Index: linux-4.19.25-rt16/arch/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/Kconfig
+++ linux-4.19.25-rt16/arch/Kconfig
@@ -28,6 +28,7 @@ config OPROFILE
 	tristate "OProfile system profiling"
 	depends on PROFILING
 	depends on HAVE_OPROFILE
+	depends on !PREEMPT_RT_FULL
 	select RING_BUFFER
 	select RING_BUFFER_ALLOW_SWAP
 	help
Index: linux-4.19.25-rt16/arch/alpha/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/alpha/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/alpha/include/asm/spinlock_types.h
@@ -2,10 +2,6 @@
 #ifndef _ALPHA_SPINLOCK_TYPES_H
 #define _ALPHA_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 typedef struct {
 	volatile unsigned int lock;
 } arch_spinlock_t;
Index: linux-4.19.25-rt16/arch/arm/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/Kconfig
+++ linux-4.19.25-rt16/arch/arm/Kconfig
@@ -51,7 +51,7 @@ config ARM
 	select HARDIRQS_SW_RESEND
 	select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
 	select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
-	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
+	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU && !PREEMPT_RT_BASE
 	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
 	select HAVE_ARCH_MMAP_RND_BITS if MMU
 	select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
@@ -90,6 +90,7 @@ config ARM
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_PREEMPT_LAZY
 	select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RSEQ
@@ -2161,7 +2162,7 @@ config NEON
 
 config KERNEL_MODE_NEON
 	bool "Support for NEON in kernel mode"
-	depends on NEON && AEABI
+	depends on NEON && AEABI && !PREEMPT_RT_BASE
 	help
 	  Say Y to include support for NEON in kernel mode.
 
Index: linux-4.19.25-rt16/arch/arm/configs/at91_dt_defconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/configs/at91_dt_defconfig
+++ linux-4.19.25-rt16/arch/arm/configs/at91_dt_defconfig
@@ -19,6 +19,7 @@ CONFIG_ARCH_MULTI_V5=y
 CONFIG_ARCH_AT91=y
 CONFIG_SOC_AT91RM9200=y
 CONFIG_SOC_AT91SAM9=y
+# CONFIG_ATMEL_CLOCKSOURCE_PIT is not set
 CONFIG_AEABI=y
 CONFIG_UACCESS_WITH_MEMCPY=y
 CONFIG_ZBOOT_ROM_TEXT=0x0
@@ -64,7 +65,6 @@ CONFIG_BLK_DEV_LOOP=y
 CONFIG_BLK_DEV_RAM=y
 CONFIG_BLK_DEV_RAM_COUNT=4
 CONFIG_BLK_DEV_RAM_SIZE=8192
-CONFIG_ATMEL_TCLIB=y
 CONFIG_ATMEL_SSC=y
 CONFIG_SCSI=y
 CONFIG_BLK_DEV_SD=y
Index: linux-4.19.25-rt16/arch/arm/configs/sama5_defconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/configs/sama5_defconfig
+++ linux-4.19.25-rt16/arch/arm/configs/sama5_defconfig
@@ -20,6 +20,7 @@ CONFIG_ARCH_AT91=y
 CONFIG_SOC_SAMA5D2=y
 CONFIG_SOC_SAMA5D3=y
 CONFIG_SOC_SAMA5D4=y
+# CONFIG_ATMEL_CLOCKSOURCE_PIT is not set
 CONFIG_AEABI=y
 CONFIG_UACCESS_WITH_MEMCPY=y
 CONFIG_ZBOOT_ROM_TEXT=0x0
@@ -75,7 +76,6 @@ CONFIG_BLK_DEV_LOOP=y
 CONFIG_BLK_DEV_RAM=y
 CONFIG_BLK_DEV_RAM_COUNT=4
 CONFIG_BLK_DEV_RAM_SIZE=8192
-CONFIG_ATMEL_TCLIB=y
 CONFIG_ATMEL_SSC=y
 CONFIG_EEPROM_AT24=y
 CONFIG_SCSI=y
Index: linux-4.19.25-rt16/arch/arm/include/asm/irq.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/include/asm/irq.h
+++ linux-4.19.25-rt16/arch/arm/include/asm/irq.h
@@ -23,6 +23,8 @@
 #endif
 
 #ifndef __ASSEMBLY__
+#include <linux/cpumask.h>
+
 struct irqaction;
 struct pt_regs;
 
Index: linux-4.19.25-rt16/arch/arm/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/arm/include/asm/spinlock_types.h
@@ -2,10 +2,6 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 #define TICKET_SHIFT	16
 
 typedef struct {
Index: linux-4.19.25-rt16/arch/arm/include/asm/switch_to.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/include/asm/switch_to.h
+++ linux-4.19.25-rt16/arch/arm/include/asm/switch_to.h
@@ -4,6 +4,13 @@
 
 #include <linux/thread_info.h>
 
+#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM
+void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p);
+#else
+static inline void
+switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { }
+#endif
+
 /*
  * For v7 SMP cores running a preemptible kernel we may be pre-empted
  * during a TLB maintenance operation, so execute an inner-shareable dsb
@@ -26,6 +33,7 @@ extern struct task_struct *__switch_to(s
 #define switch_to(prev,next,last)					\
 do {									\
 	__complete_pending_tlbi();					\
+	switch_kmaps(prev, next);					\
 	last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));	\
 } while (0)
 
Index: linux-4.19.25-rt16/arch/arm/include/asm/thread_info.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/include/asm/thread_info.h
+++ linux-4.19.25-rt16/arch/arm/include/asm/thread_info.h
@@ -49,6 +49,7 @@ struct cpu_context_save {
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	int			preempt_count;	/* 0 => preemptable, <0 => bug */
+	int			preempt_lazy_count; /* 0 => preemptable, <0 => bug */
 	mm_segment_t		addr_limit;	/* address limit */
 	struct task_struct	*task;		/* main task structure */
 	__u32			cpu;		/* cpu */
@@ -139,7 +140,8 @@ extern int vfp_restore_user_hwstate(stru
 #define TIF_SYSCALL_TRACE	4	/* syscall trace active */
 #define TIF_SYSCALL_AUDIT	5	/* syscall auditing active */
 #define TIF_SYSCALL_TRACEPOINT	6	/* syscall tracepoint instrumentation */
-#define TIF_SECCOMP		7	/* seccomp syscall filtering active */
+#define TIF_SECCOMP		8	/* seccomp syscall filtering active */
+#define TIF_NEED_RESCHED_LAZY	7
 
 #define TIF_NOHZ		12	/* in adaptive nohz mode */
 #define TIF_USING_IWMMXT	17
@@ -149,6 +151,7 @@ extern int vfp_restore_user_hwstate(stru
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 #define _TIF_UPROBE		(1 << TIF_UPROBE)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
@@ -164,7 +167,8 @@ extern int vfp_restore_user_hwstate(stru
  * Change these and you break ASM code in entry-common.S
  */
 #define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
-				 _TIF_NOTIFY_RESUME | _TIF_UPROBE)
+				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
+				 _TIF_NEED_RESCHED_LAZY)
 
 #endif /* __KERNEL__ */
 #endif /* __ASM_ARM_THREAD_INFO_H */
Index: linux-4.19.25-rt16/arch/arm/kernel/asm-offsets.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/kernel/asm-offsets.c
+++ linux-4.19.25-rt16/arch/arm/kernel/asm-offsets.c
@@ -56,6 +56,7 @@ int main(void)
   BLANK();
   DEFINE(TI_FLAGS,		offsetof(struct thread_info, flags));
   DEFINE(TI_PREEMPT,		offsetof(struct thread_info, preempt_count));
+  DEFINE(TI_PREEMPT_LAZY,	offsetof(struct thread_info, preempt_lazy_count));
   DEFINE(TI_ADDR_LIMIT,		offsetof(struct thread_info, addr_limit));
   DEFINE(TI_TASK,		offsetof(struct thread_info, task));
   DEFINE(TI_CPU,		offsetof(struct thread_info, cpu));
Index: linux-4.19.25-rt16/arch/arm/kernel/entry-armv.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/kernel/entry-armv.S
+++ linux-4.19.25-rt16/arch/arm/kernel/entry-armv.S
@@ -216,11 +216,18 @@ __irq_svc:
 
 #ifdef CONFIG_PREEMPT
 	ldr	r8, [tsk, #TI_PREEMPT]		@ get preempt count
-	ldr	r0, [tsk, #TI_FLAGS]		@ get flags
 	teq	r8, #0				@ if preempt count != 0
+	bne	1f				@ return from exeption
+	ldr	r0, [tsk, #TI_FLAGS]		@ get flags
+	tst	r0, #_TIF_NEED_RESCHED		@ if NEED_RESCHED is set
+	blne	svc_preempt			@ preempt!
+
+	ldr	r8, [tsk, #TI_PREEMPT_LAZY]	@ get preempt lazy count
+	teq	r8, #0				@ if preempt lazy count != 0
 	movne	r0, #0				@ force flags to 0
-	tst	r0, #_TIF_NEED_RESCHED
+	tst	r0, #_TIF_NEED_RESCHED_LAZY
 	blne	svc_preempt
+1:
 #endif
 
 	svc_exit r5, irq = 1			@ return from exception
@@ -235,8 +242,14 @@ svc_preempt:
 1:	bl	preempt_schedule_irq		@ irq en/disable is done inside
 	ldr	r0, [tsk, #TI_FLAGS]		@ get new tasks TI_FLAGS
 	tst	r0, #_TIF_NEED_RESCHED
+	bne	1b
+	tst	r0, #_TIF_NEED_RESCHED_LAZY
 	reteq	r8				@ go again
-	b	1b
+	ldr	r0, [tsk, #TI_PREEMPT_LAZY]	@ get preempt lazy count
+	teq	r0, #0				@ if preempt lazy count != 0
+	beq	1b
+	ret	r8				@ go again
+
 #endif
 
 __und_fault:
Index: linux-4.19.25-rt16/arch/arm/kernel/entry-common.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/kernel/entry-common.S
+++ linux-4.19.25-rt16/arch/arm/kernel/entry-common.S
@@ -56,7 +56,9 @@ __ret_fast_syscall:
 	cmp	r2, #TASK_SIZE
 	blne	addr_limit_check_failed
 	ldr	r1, [tsk, #TI_FLAGS]		@ re-check for syscall tracing
-	tst	r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
+	tst	r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP)
+	bne	fast_work_pending
+	tst	r1, #_TIF_SECCOMP
 	bne	fast_work_pending
 
 
@@ -93,8 +95,11 @@ __ret_fast_syscall:
 	cmp	r2, #TASK_SIZE
 	blne	addr_limit_check_failed
 	ldr	r1, [tsk, #TI_FLAGS]		@ re-check for syscall tracing
-	tst	r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
+	tst	r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP)
+	bne	do_slower_path
+	tst	r1, #_TIF_SECCOMP
 	beq	no_work_pending
+do_slower_path:
  UNWIND(.fnend		)
 ENDPROC(ret_fast_syscall)
 
Index: linux-4.19.25-rt16/arch/arm/kernel/process.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/kernel/process.c
+++ linux-4.19.25-rt16/arch/arm/kernel/process.c
@@ -324,6 +324,30 @@ unsigned long arch_randomize_brk(struct
 }
 
 #ifdef CONFIG_MMU
+/*
+ * CONFIG_SPLIT_PTLOCK_CPUS results in a page->ptl lock.  If the lock is not
+ * initialized by pgtable_page_ctor() then a coredump of the vector page will
+ * fail.
+ */
+static int __init vectors_user_mapping_init_page(void)
+{
+	struct page *page;
+	unsigned long addr = 0xffff0000;
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pgd = pgd_offset_k(addr);
+	pud = pud_offset(pgd, addr);
+	pmd = pmd_offset(pud, addr);
+	page = pmd_page(*(pmd));
+
+	pgtable_page_ctor(page);
+
+	return 0;
+}
+late_initcall(vectors_user_mapping_init_page);
+
 #ifdef CONFIG_KUSER_HELPERS
 /*
  * The vectors page is always readable from user space for the
Index: linux-4.19.25-rt16/arch/arm/kernel/signal.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/kernel/signal.c
+++ linux-4.19.25-rt16/arch/arm/kernel/signal.c
@@ -652,7 +652,8 @@ do_work_pending(struct pt_regs *regs, un
 	 */
 	trace_hardirqs_off();
 	do {
-		if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+		if (likely(thread_flags & (_TIF_NEED_RESCHED |
+					   _TIF_NEED_RESCHED_LAZY))) {
 			schedule();
 		} else {
 			if (unlikely(!user_mode(regs)))
Index: linux-4.19.25-rt16/arch/arm/mach-at91/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mach-at91/Kconfig
+++ linux-4.19.25-rt16/arch/arm/mach-at91/Kconfig
@@ -107,6 +107,31 @@ config SOC_AT91SAM9
 	    AT91SAM9X35
 	    AT91SAM9XE
 
+comment "Clocksource driver selection"
+
+config ATMEL_CLOCKSOURCE_PIT
+	bool "Periodic Interval Timer (PIT) support"
+	depends on SOC_AT91SAM9 || SOC_SAMA5
+	default SOC_AT91SAM9 || SOC_SAMA5
+	select ATMEL_PIT
+	help
+	  Select this to get a clocksource based on the Atmel Periodic Interval
+	  Timer. It has a relatively low resolution and the TC Block clocksource
+	  should be preferred.
+
+config ATMEL_CLOCKSOURCE_TCB
+	bool "Timer Counter Blocks (TCB) support"
+	depends on SOC_AT91RM9200 || SOC_AT91SAM9 || SOC_SAMA5 || COMPILE_TEST
+	default SOC_AT91RM9200 || SOC_AT91SAM9 || SOC_SAMA5
+	depends on !ATMEL_TCLIB
+	select ATMEL_ARM_TCB_CLKSRC
+	help
+	  Select this to get a high precision clocksource based on a
+	  TC block with a 5+ MHz base clock rate.
+	  On platforms with 16-bit counters, two timer channels are combined
+	  to make a single 32-bit timer.
+	  It can also be used as a clock event device supporting oneshot mode.
+
 config HAVE_AT91_UTMI
 	bool
 
Index: linux-4.19.25-rt16/arch/arm/mach-exynos/platsmp.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mach-exynos/platsmp.c
+++ linux-4.19.25-rt16/arch/arm/mach-exynos/platsmp.c
@@ -239,7 +239,7 @@ static void write_pen_release(int val)
 	sync_cache_w(&pen_release);
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static void exynos_secondary_init(unsigned int cpu)
 {
@@ -252,8 +252,8 @@ static void exynos_secondary_init(unsign
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 int exynos_set_boot_addr(u32 core_id, unsigned long boot_addr)
@@ -317,7 +317,7 @@ static int exynos_boot_secondary(unsigne
 	 * Set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -344,7 +344,7 @@ static int exynos_boot_secondary(unsigne
 
 		if (timeout == 0) {
 			printk(KERN_ERR "cpu1 power enable failed");
-			spin_unlock(&boot_lock);
+			raw_spin_unlock(&boot_lock);
 			return -ETIMEDOUT;
 		}
 	}
@@ -390,7 +390,7 @@ static int exynos_boot_secondary(unsigne
 	 * calibrations, then wait for it to finish
 	 */
 fail:
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? ret : 0;
 }
Index: linux-4.19.25-rt16/arch/arm/mach-hisi/platmcpm.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mach-hisi/platmcpm.c
+++ linux-4.19.25-rt16/arch/arm/mach-hisi/platmcpm.c
@@ -61,7 +61,7 @@
 
 static void __iomem *sysctrl, *fabric;
 static int hip04_cpu_table[HIP04_MAX_CLUSTERS][HIP04_MAX_CPUS_PER_CLUSTER];
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 static u32 fabric_phys_addr;
 /*
  * [0]: bootwrapper physical address
@@ -113,7 +113,7 @@ static int hip04_boot_secondary(unsigned
 	if (cluster >= HIP04_MAX_CLUSTERS || cpu >= HIP04_MAX_CPUS_PER_CLUSTER)
 		return -EINVAL;
 
-	spin_lock_irq(&boot_lock);
+	raw_spin_lock_irq(&boot_lock);
 
 	if (hip04_cpu_table[cluster][cpu])
 		goto out;
@@ -147,7 +147,7 @@ static int hip04_boot_secondary(unsigned
 
 out:
 	hip04_cpu_table[cluster][cpu]++;
-	spin_unlock_irq(&boot_lock);
+	raw_spin_unlock_irq(&boot_lock);
 
 	return 0;
 }
@@ -162,11 +162,11 @@ static void hip04_cpu_die(unsigned int l
 	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 	hip04_cpu_table[cluster][cpu]--;
 	if (hip04_cpu_table[cluster][cpu] == 1) {
 		/* A power_up request went ahead of us. */
-		spin_unlock(&boot_lock);
+		raw_spin_unlock(&boot_lock);
 		return;
 	} else if (hip04_cpu_table[cluster][cpu] > 1) {
 		pr_err("Cluster %d CPU%d boots multiple times\n", cluster, cpu);
@@ -174,7 +174,7 @@ static void hip04_cpu_die(unsigned int l
 	}
 
 	last_man = hip04_cluster_is_down(cluster);
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 	if (last_man) {
 		/* Since it's Cortex A15, disable L2 prefetching. */
 		asm volatile(
@@ -203,7 +203,7 @@ static int hip04_cpu_kill(unsigned int l
 	       cpu >= HIP04_MAX_CPUS_PER_CLUSTER);
 
 	count = TIMEOUT_MSEC / POLL_MSEC;
-	spin_lock_irq(&boot_lock);
+	raw_spin_lock_irq(&boot_lock);
 	for (tries = 0; tries < count; tries++) {
 		if (hip04_cpu_table[cluster][cpu])
 			goto err;
@@ -211,10 +211,10 @@ static int hip04_cpu_kill(unsigned int l
 		data = readl_relaxed(sysctrl + SC_CPU_RESET_STATUS(cluster));
 		if (data & CORE_WFI_STATUS(cpu))
 			break;
-		spin_unlock_irq(&boot_lock);
+		raw_spin_unlock_irq(&boot_lock);
 		/* Wait for clean L2 when the whole cluster is down. */
 		msleep(POLL_MSEC);
-		spin_lock_irq(&boot_lock);
+		raw_spin_lock_irq(&boot_lock);
 	}
 	if (tries >= count)
 		goto err;
@@ -231,10 +231,10 @@ static int hip04_cpu_kill(unsigned int l
 		goto err;
 	if (hip04_cluster_is_down(cluster))
 		hip04_set_snoop_filter(cluster, 0);
-	spin_unlock_irq(&boot_lock);
+	raw_spin_unlock_irq(&boot_lock);
 	return 1;
 err:
-	spin_unlock_irq(&boot_lock);
+	raw_spin_unlock_irq(&boot_lock);
 	return 0;
 }
 #endif
Index: linux-4.19.25-rt16/arch/arm/mach-omap2/omap-smp.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mach-omap2/omap-smp.c
+++ linux-4.19.25-rt16/arch/arm/mach-omap2/omap-smp.c
@@ -69,7 +69,7 @@ static const struct omap_smp_config omap
 	.startup_addr = omap5_secondary_startup,
 };
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 void __iomem *omap4_get_scu_base(void)
 {
@@ -177,8 +177,8 @@ static void omap4_secondary_init(unsigne
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -191,7 +191,7 @@ static int omap4_boot_secondary(unsigned
 	 * Set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * Update the AuxCoreBoot0 with boot state for secondary core.
@@ -270,7 +270,7 @@ static int omap4_boot_secondary(unsigned
 	 * Now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return 0;
 }
Index: linux-4.19.25-rt16/arch/arm/mach-prima2/platsmp.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mach-prima2/platsmp.c
+++ linux-4.19.25-rt16/arch/arm/mach-prima2/platsmp.c
@@ -22,7 +22,7 @@
 
 static void __iomem *clk_base;
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static void sirfsoc_secondary_init(unsigned int cpu)
 {
@@ -36,8 +36,8 @@ static void sirfsoc_secondary_init(unsig
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static const struct of_device_id clk_ids[]  = {
@@ -75,7 +75,7 @@ static int sirfsoc_boot_secondary(unsign
 	/* make sure write buffer is drained */
 	mb();
 
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -107,7 +107,7 @@ static int sirfsoc_boot_secondary(unsign
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
Index: linux-4.19.25-rt16/arch/arm/mach-qcom/platsmp.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mach-qcom/platsmp.c
+++ linux-4.19.25-rt16/arch/arm/mach-qcom/platsmp.c
@@ -46,7 +46,7 @@
 
 extern void secondary_startup_arm(void);
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 #ifdef CONFIG_HOTPLUG_CPU
 static void qcom_cpu_die(unsigned int cpu)
@@ -60,8 +60,8 @@ static void qcom_secondary_init(unsigned
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int scss_release_secondary(unsigned int cpu)
@@ -284,7 +284,7 @@ static int qcom_boot_secondary(unsigned
 	 * set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * Send the secondary CPU a soft interrupt, thereby causing
@@ -297,7 +297,7 @@ static int qcom_boot_secondary(unsigned
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return ret;
 }
Index: linux-4.19.25-rt16/arch/arm/mach-spear/platsmp.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mach-spear/platsmp.c
+++ linux-4.19.25-rt16/arch/arm/mach-spear/platsmp.c
@@ -32,7 +32,7 @@ static void write_pen_release(int val)
 	sync_cache_w(&pen_release);
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static void __iomem *scu_base = IOMEM(VA_SCU_BASE);
 
@@ -47,8 +47,8 @@ static void spear13xx_secondary_init(uns
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -59,7 +59,7 @@ static int spear13xx_boot_secondary(unsi
 	 * set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -84,7 +84,7 @@ static int spear13xx_boot_secondary(unsi
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
Index: linux-4.19.25-rt16/arch/arm/mach-sti/platsmp.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mach-sti/platsmp.c
+++ linux-4.19.25-rt16/arch/arm/mach-sti/platsmp.c
@@ -35,7 +35,7 @@ static void write_pen_release(int val)
 	sync_cache_w(&pen_release);
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static void sti_secondary_init(unsigned int cpu)
 {
@@ -48,8 +48,8 @@ static void sti_secondary_init(unsigned
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int sti_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -60,7 +60,7 @@ static int sti_boot_secondary(unsigned i
 	 * set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -91,7 +91,7 @@ static int sti_boot_secondary(unsigned i
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
Index: linux-4.19.25-rt16/arch/arm/mm/fault.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mm/fault.c
+++ linux-4.19.25-rt16/arch/arm/mm/fault.c
@@ -439,6 +439,9 @@ do_translation_fault(unsigned long addr,
 	if (addr < TASK_SIZE)
 		return do_page_fault(addr, fsr, regs);
 
+	if (interrupts_enabled(regs))
+		local_irq_enable();
+
 	if (user_mode(regs))
 		goto bad_area;
 
@@ -506,6 +509,9 @@ do_translation_fault(unsigned long addr,
 static int
 do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
+	if (interrupts_enabled(regs))
+		local_irq_enable();
+
 	do_bad_area(addr, fsr, regs);
 	return 0;
 }
Index: linux-4.19.25-rt16/arch/arm/mm/highmem.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/mm/highmem.c
+++ linux-4.19.25-rt16/arch/arm/mm/highmem.c
@@ -34,6 +34,11 @@ static inline pte_t get_fixmap_pte(unsig
 	return *ptep;
 }
 
+static unsigned int fixmap_idx(int type)
+{
+	return FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
+}
+
 void *kmap(struct page *page)
 {
 	might_sleep();
@@ -54,12 +59,13 @@ EXPORT_SYMBOL(kunmap);
 
 void *kmap_atomic(struct page *page)
 {
+	pte_t pte = mk_pte(page, kmap_prot);
 	unsigned int idx;
 	unsigned long vaddr;
 	void *kmap;
 	int type;
 
-	preempt_disable();
+	preempt_disable_nort();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
@@ -79,7 +85,7 @@ void *kmap_atomic(struct page *page)
 
 	type = kmap_atomic_idx_push();
 
-	idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
+	idx = fixmap_idx(type);
 	vaddr = __fix_to_virt(idx);
 #ifdef CONFIG_DEBUG_HIGHMEM
 	/*
@@ -93,7 +99,10 @@ void *kmap_atomic(struct page *page)
 	 * in place, so the contained TLB flush ensures the TLB is updated
 	 * with the new mapping.
 	 */
-	set_fixmap_pte(idx, mk_pte(page, kmap_prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+	current->kmap_pte[type] = pte;
+#endif
+	set_fixmap_pte(idx, pte);
 
 	return (void *)vaddr;
 }
@@ -106,44 +115,75 @@ void __kunmap_atomic(void *kvaddr)
 
 	if (kvaddr >= (void *)FIXADDR_START) {
 		type = kmap_atomic_idx();
-		idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
+		idx = fixmap_idx(type);
 
 		if (cache_is_vivt())
 			__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
+#ifdef CONFIG_PREEMPT_RT_FULL
+		current->kmap_pte[type] = __pte(0);
+#endif
 #ifdef CONFIG_DEBUG_HIGHMEM
 		BUG_ON(vaddr != __fix_to_virt(idx));
-		set_fixmap_pte(idx, __pte(0));
 #else
 		(void) idx;  /* to kill a warning */
 #endif
+		set_fixmap_pte(idx, __pte(0));
 		kmap_atomic_idx_pop();
 	} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
 		/* this address was obtained through kmap_high_get() */
 		kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
 	}
 	pagefault_enable();
-	preempt_enable();
+	preempt_enable_nort();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
 void *kmap_atomic_pfn(unsigned long pfn)
 {
+	pte_t pte = pfn_pte(pfn, kmap_prot);
 	unsigned long vaddr;
 	int idx, type;
 	struct page *page = pfn_to_page(pfn);
 
-	preempt_disable();
+	preempt_disable_nort();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
 
 	type = kmap_atomic_idx_push();
-	idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
+	idx = fixmap_idx(type);
 	vaddr = __fix_to_virt(idx);
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
 #endif
-	set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+	current->kmap_pte[type] = pte;
+#endif
+	set_fixmap_pte(idx, pte);
 
 	return (void *)vaddr;
 }
+#if defined CONFIG_PREEMPT_RT_FULL
+void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p)
+{
+	int i;
+
+	/*
+	 * Clear @prev's kmap_atomic mappings
+	 */
+	for (i = 0; i < prev_p->kmap_idx; i++) {
+		int idx = fixmap_idx(i);
+
+		set_fixmap_pte(idx, __pte(0));
+	}
+	/*
+	 * Restore @next_p's kmap_atomic mappings
+	 */
+	for (i = 0; i < next_p->kmap_idx; i++) {
+		int idx = fixmap_idx(i);
+
+		if (!pte_none(next_p->kmap_pte[i]))
+			set_fixmap_pte(idx, next_p->kmap_pte[i]);
+	}
+}
+#endif
Index: linux-4.19.25-rt16/arch/arm/plat-versatile/platsmp.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm/plat-versatile/platsmp.c
+++ linux-4.19.25-rt16/arch/arm/plat-versatile/platsmp.c
@@ -32,7 +32,7 @@ static void write_pen_release(int val)
 	sync_cache_w(&pen_release);
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 void versatile_secondary_init(unsigned int cpu)
 {
@@ -45,8 +45,8 @@ void versatile_secondary_init(unsigned i
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -57,7 +57,7 @@ int versatile_boot_secondary(unsigned in
 	 * Set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * This is really belt and braces; we hold unintended secondary
@@ -87,7 +87,7 @@ int versatile_boot_secondary(unsigned in
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
Index: linux-4.19.25-rt16/arch/arm64/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/Kconfig
+++ linux-4.19.25-rt16/arch/arm64/Kconfig
@@ -140,6 +140,7 @@ config ARM64
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_PREEMPT_LAZY
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RCU_TABLE_FREE
 	select HAVE_RSEQ
Index: linux-4.19.25-rt16/arch/arm64/crypto/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/crypto/Kconfig
+++ linux-4.19.25-rt16/arch/arm64/crypto/Kconfig
@@ -19,43 +19,43 @@ config CRYPTO_SHA512_ARM64
 
 config CRYPTO_SHA1_ARM64_CE
 	tristate "SHA-1 digest algorithm (ARMv8 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SHA1
 
 config CRYPTO_SHA2_ARM64_CE
 	tristate "SHA-224/SHA-256 digest algorithm (ARMv8 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SHA256_ARM64
 
 config CRYPTO_SHA512_ARM64_CE
 	tristate "SHA-384/SHA-512 digest algorithm (ARMv8 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SHA512_ARM64
 
 config CRYPTO_SHA3_ARM64
 	tristate "SHA3 digest algorithm (ARMv8.2 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SHA3
 
 config CRYPTO_SM3_ARM64_CE
 	tristate "SM3 digest algorithm (ARMv8.2 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_SM3
 
 config CRYPTO_SM4_ARM64_CE
 	tristate "SM4 symmetric cipher (ARMv8.2 Crypto Extensions)"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_ALGAPI
 	select CRYPTO_SM4
 
 config CRYPTO_GHASH_ARM64_CE
 	tristate "GHASH/AES-GCM using ARMv8 Crypto Extensions"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 	select CRYPTO_GF128MUL
 	select CRYPTO_AES
@@ -63,7 +63,7 @@ config CRYPTO_GHASH_ARM64_CE
 
 config CRYPTO_CRCT10DIF_ARM64_CE
 	tristate "CRCT10DIF digest algorithm using PMULL instructions"
-	depends on KERNEL_MODE_NEON && CRC_T10DIF
+	depends on KERNEL_MODE_NEON && CRC_T10DIF && !PREEMPT_RT_BASE
 	select CRYPTO_HASH
 
 config CRYPTO_CRC32_ARM64_CE
@@ -77,13 +77,13 @@ config CRYPTO_AES_ARM64
 
 config CRYPTO_AES_ARM64_CE
 	tristate "AES core cipher using ARMv8 Crypto Extensions"
-	depends on ARM64 && KERNEL_MODE_NEON
+	depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_ALGAPI
 	select CRYPTO_AES_ARM64
 
 config CRYPTO_AES_ARM64_CE_CCM
 	tristate "AES in CCM mode using ARMv8 Crypto Extensions"
-	depends on ARM64 && KERNEL_MODE_NEON
+	depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_ALGAPI
 	select CRYPTO_AES_ARM64_CE
 	select CRYPTO_AES_ARM64
@@ -91,7 +91,7 @@ config CRYPTO_AES_ARM64_CE_CCM
 
 config CRYPTO_AES_ARM64_CE_BLK
 	tristate "AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_AES_ARM64_CE
 	select CRYPTO_AES_ARM64
@@ -99,7 +99,7 @@ config CRYPTO_AES_ARM64_CE_BLK
 
 config CRYPTO_AES_ARM64_NEON_BLK
 	tristate "AES in ECB/CBC/CTR/XTS modes using NEON instructions"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_AES_ARM64
 	select CRYPTO_AES
@@ -107,13 +107,13 @@ config CRYPTO_AES_ARM64_NEON_BLK
 
 config CRYPTO_CHACHA20_NEON
 	tristate "NEON accelerated ChaCha20 symmetric cipher"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_CHACHA20
 
 config CRYPTO_AES_ARM64_BS
 	tristate "AES in ECB/CBC/CTR/XTS modes using bit-sliced NEON algorithm"
-	depends on KERNEL_MODE_NEON
+	depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_AES_ARM64_NEON_BLK
 	select CRYPTO_AES_ARM64
Index: linux-4.19.25-rt16/arch/arm64/crypto/crc32-ce-glue.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/crypto/crc32-ce-glue.c
+++ linux-4.19.25-rt16/arch/arm64/crypto/crc32-ce-glue.c
@@ -208,7 +208,8 @@ static struct shash_alg crc32_pmull_algs
 
 static int __init crc32_pmull_mod_init(void)
 {
-	if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_PMULL)) {
+	if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
+	    !IS_ENABLED(CONFIG_PREEMPT_RT_BASE) && (elf_hwcap & HWCAP_PMULL)) {
 		crc32_pmull_algs[0].update = crc32_pmull_update;
 		crc32_pmull_algs[1].update = crc32c_pmull_update;
 
Index: linux-4.19.25-rt16/arch/arm64/include/asm/alternative.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/include/asm/alternative.h
+++ linux-4.19.25-rt16/arch/arm64/include/asm/alternative.h
@@ -35,6 +35,12 @@ void apply_alternatives_module(void *sta
 static inline void apply_alternatives_module(void *start, size_t length) { }
 #endif
 
+#ifdef CONFIG_KVM_ARM_HOST
+void kvm_compute_layout(void);
+#else
+static inline void kvm_compute_layout(void) { }
+#endif
+
 #define ALTINSTR_ENTRY(feature,cb)					      \
 	" .word 661b - .\n"				/* label           */ \
 	" .if " __stringify(cb) " == 0\n"				      \
Index: linux-4.19.25-rt16/arch/arm64/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/arm64/include/asm/spinlock_types.h
@@ -16,10 +16,6 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#if !defined(__LINUX_SPINLOCK_TYPES_H) && !defined(__ASM_SPINLOCK_H)
-# error "please don't include this file directly"
-#endif
-
 #include <asm-generic/qspinlock_types.h>
 #include <asm-generic/qrwlock_types.h>
 
Index: linux-4.19.25-rt16/arch/arm64/include/asm/thread_info.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/include/asm/thread_info.h
+++ linux-4.19.25-rt16/arch/arm64/include/asm/thread_info.h
@@ -43,6 +43,7 @@ struct thread_info {
 	u64			ttbr0;		/* saved TTBR0_EL1 */
 #endif
 	int			preempt_count;	/* 0 => preemptable, <0 => bug */
+	int			preempt_lazy_count; /* 0 => preemptable, <0 => bug */
 };
 
 #define thread_saved_pc(tsk)	\
@@ -76,6 +77,7 @@ void arch_release_task_struct(struct tas
 #define TIF_FOREIGN_FPSTATE	3	/* CPU's FP state is not current's */
 #define TIF_UPROBE		4	/* uprobe breakpoint or singlestep */
 #define TIF_FSCHECK		5	/* Check FS is USER_DS on return */
+#define TIF_NEED_RESCHED_LAZY	6
 #define TIF_NOHZ		7
 #define TIF_SYSCALL_TRACE	8
 #define TIF_SYSCALL_AUDIT	9
@@ -94,6 +96,7 @@ void arch_release_task_struct(struct tas
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 #define _TIF_FOREIGN_FPSTATE	(1 << TIF_FOREIGN_FPSTATE)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 #define _TIF_NOHZ		(1 << TIF_NOHZ)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
@@ -106,8 +109,9 @@ void arch_release_task_struct(struct tas
 
 #define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
 				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
-				 _TIF_UPROBE | _TIF_FSCHECK)
+				 _TIF_UPROBE | _TIF_FSCHECK | _TIF_NEED_RESCHED_LAZY)
 
+#define _TIF_NEED_RESCHED_MASK	(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
 #define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
 				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
 				 _TIF_NOHZ)
Index: linux-4.19.25-rt16/arch/arm64/kernel/alternative.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/kernel/alternative.c
+++ linux-4.19.25-rt16/arch/arm64/kernel/alternative.c
@@ -224,6 +224,7 @@ static int __apply_alternatives_multi_st
 void __init apply_alternatives_all(void)
 {
 	/* better not try code patching on a live SMP system */
+	kvm_compute_layout();
 	stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask);
 }
 
Index: linux-4.19.25-rt16/arch/arm64/kernel/asm-offsets.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/kernel/asm-offsets.c
+++ linux-4.19.25-rt16/arch/arm64/kernel/asm-offsets.c
@@ -41,6 +41,7 @@ int main(void)
   BLANK();
   DEFINE(TSK_TI_FLAGS,		offsetof(struct task_struct, thread_info.flags));
   DEFINE(TSK_TI_PREEMPT,	offsetof(struct task_struct, thread_info.preempt_count));
+  DEFINE(TSK_TI_PREEMPT_LAZY,	offsetof(struct task_struct, thread_info.preempt_lazy_count));
   DEFINE(TSK_TI_ADDR_LIMIT,	offsetof(struct task_struct, thread_info.addr_limit));
 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
   DEFINE(TSK_TI_TTBR0,		offsetof(struct task_struct, thread_info.ttbr0));
Index: linux-4.19.25-rt16/arch/arm64/kernel/entry.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/kernel/entry.S
+++ linux-4.19.25-rt16/arch/arm64/kernel/entry.S
@@ -623,11 +623,16 @@ el1_irq:
 
 #ifdef CONFIG_PREEMPT
 	ldr	w24, [tsk, #TSK_TI_PREEMPT]	// get preempt count
-	cbnz	w24, 1f				// preempt count != 0
+	cbnz	w24, 2f				// preempt count != 0
 	ldr	x0, [tsk, #TSK_TI_FLAGS]	// get flags
-	tbz	x0, #TIF_NEED_RESCHED, 1f	// needs rescheduling?
-	bl	el1_preempt
+	tbnz	x0, #TIF_NEED_RESCHED, 1f	// needs rescheduling?
+
+	ldr	w24, [tsk, #TSK_TI_PREEMPT_LAZY] // get preempt lazy count
+	cbnz	w24, 2f				// preempt lazy count != 0
+	tbz	x0, #TIF_NEED_RESCHED_LAZY, 2f	// needs rescheduling?
 1:
+	bl	el1_preempt
+2:
 #endif
 #ifdef CONFIG_TRACE_IRQFLAGS
 	bl	trace_hardirqs_on
@@ -641,6 +646,7 @@ el1_preempt:
 1:	bl	preempt_schedule_irq		// irq en/disable is done inside
 	ldr	x0, [tsk, #TSK_TI_FLAGS]	// get new tasks TI_FLAGS
 	tbnz	x0, #TIF_NEED_RESCHED, 1b	// needs rescheduling?
+	tbnz	x0, #TIF_NEED_RESCHED_LAZY, 1b	// needs rescheduling?
 	ret	x24
 #endif
 
Index: linux-4.19.25-rt16/arch/arm64/kernel/fpsimd.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/kernel/fpsimd.c
+++ linux-4.19.25-rt16/arch/arm64/kernel/fpsimd.c
@@ -159,6 +159,16 @@ static void sve_free(struct task_struct
 	__sve_free(task);
 }
 
+static void *sve_free_atomic(struct task_struct *task)
+{
+	void *sve_state = task->thread.sve_state;
+
+	WARN_ON(test_tsk_thread_flag(task, TIF_SVE));
+
+	task->thread.sve_state = NULL;
+	return sve_state;
+}
+
 /*
  * TIF_SVE controls whether a task can use SVE without trapping while
  * in userspace, and also the way a task's FPSIMD/SVE state is stored
@@ -547,6 +557,7 @@ int sve_set_vector_length(struct task_st
 	 * non-SVE thread.
 	 */
 	if (task == current) {
+		preempt_disable();
 		local_bh_disable();
 
 		fpsimd_save();
@@ -557,8 +568,10 @@ int sve_set_vector_length(struct task_st
 	if (test_and_clear_tsk_thread_flag(task, TIF_SVE))
 		sve_to_fpsimd(task);
 
-	if (task == current)
+	if (task == current) {
 		local_bh_enable();
+		preempt_enable();
+	}
 
 	/*
 	 * Force reallocation of task SVE state to the correct size
@@ -813,6 +826,7 @@ asmlinkage void do_sve_acc(unsigned int
 
 	sve_alloc(current);
 
+	preempt_disable();
 	local_bh_disable();
 
 	fpsimd_save();
@@ -826,6 +840,7 @@ asmlinkage void do_sve_acc(unsigned int
 		WARN_ON(1); /* SVE access shouldn't have trapped */
 
 	local_bh_enable();
+	preempt_enable();
 }
 
 /*
@@ -892,10 +907,12 @@ void fpsimd_thread_switch(struct task_st
 void fpsimd_flush_thread(void)
 {
 	int vl, supported_vl;
+	void *mem = NULL;
 
 	if (!system_supports_fpsimd())
 		return;
 
+	preempt_disable();
 	local_bh_disable();
 
 	memset(&current->thread.uw.fpsimd_state, 0,
@@ -904,7 +921,7 @@ void fpsimd_flush_thread(void)
 
 	if (system_supports_sve()) {
 		clear_thread_flag(TIF_SVE);
-		sve_free(current);
+		mem = sve_free_atomic(current);
 
 		/*
 		 * Reset the task vector length as required.
@@ -940,6 +957,8 @@ void fpsimd_flush_thread(void)
 	set_thread_flag(TIF_FOREIGN_FPSTATE);
 
 	local_bh_enable();
+	preempt_enable();
+	kfree(mem);
 }
 
 /*
@@ -951,9 +970,11 @@ void fpsimd_preserve_current_state(void)
 	if (!system_supports_fpsimd())
 		return;
 
+	preempt_disable();
 	local_bh_disable();
 	fpsimd_save();
 	local_bh_enable();
+	preempt_enable();
 }
 
 /*
@@ -1011,6 +1032,7 @@ void fpsimd_restore_current_state(void)
 	if (!system_supports_fpsimd())
 		return;
 
+	preempt_disable();
 	local_bh_disable();
 
 	if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) {
@@ -1019,6 +1041,7 @@ void fpsimd_restore_current_state(void)
 	}
 
 	local_bh_enable();
+	preempt_enable();
 }
 
 /*
@@ -1031,6 +1054,7 @@ void fpsimd_update_current_state(struct
 	if (!system_supports_fpsimd())
 		return;
 
+	preempt_disable();
 	local_bh_disable();
 
 	current->thread.uw.fpsimd_state = *state;
@@ -1043,6 +1067,7 @@ void fpsimd_update_current_state(struct
 	clear_thread_flag(TIF_FOREIGN_FPSTATE);
 
 	local_bh_enable();
+	preempt_enable();
 }
 
 /*
@@ -1088,6 +1113,7 @@ void kernel_neon_begin(void)
 
 	BUG_ON(!may_use_simd());
 
+	preempt_disable();
 	local_bh_disable();
 
 	__this_cpu_write(kernel_neon_busy, true);
@@ -1101,6 +1127,7 @@ void kernel_neon_begin(void)
 	preempt_disable();
 
 	local_bh_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(kernel_neon_begin);
 
Index: linux-4.19.25-rt16/arch/arm64/kernel/signal.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/kernel/signal.c
+++ linux-4.19.25-rt16/arch/arm64/kernel/signal.c
@@ -926,7 +926,7 @@ asmlinkage void do_notify_resume(struct
 		/* Check valid user FS if needed */
 		addr_limit_user_check();
 
-		if (thread_flags & _TIF_NEED_RESCHED) {
+		if (thread_flags & _TIF_NEED_RESCHED_MASK) {
 			/* Unmask Debug and SError for the next task */
 			local_daif_restore(DAIF_PROCCTX_NOIRQ);
 
Index: linux-4.19.25-rt16/arch/arm64/kvm/va_layout.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/arm64/kvm/va_layout.c
+++ linux-4.19.25-rt16/arch/arm64/kvm/va_layout.c
@@ -33,7 +33,7 @@ static u8 tag_lsb;
 static u64 tag_val;
 static u64 va_mask;
 
-static void compute_layout(void)
+__init void kvm_compute_layout(void)
 {
 	phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start);
 	u64 hyp_va_msb;
@@ -121,8 +121,6 @@ void __init kvm_update_va_mask(struct al
 
 	BUG_ON(nr_inst != 5);
 
-	if (!has_vhe() && !va_mask)
-		compute_layout();
 
 	for (i = 0; i < nr_inst; i++) {
 		u32 rd, rn, insn, oinsn;
@@ -167,9 +165,6 @@ void kvm_patch_vector_branch(struct alt_
 		return;
 	}
 
-	if (!va_mask)
-		compute_layout();
-
 	/*
 	 * Compute HYP VA by using the same computation as kern_hyp_va()
 	 */
Index: linux-4.19.25-rt16/arch/hexagon/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/hexagon/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/hexagon/include/asm/spinlock_types.h
@@ -21,10 +21,6 @@
 #ifndef _ASM_SPINLOCK_TYPES_H
 #define _ASM_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 typedef struct {
 	volatile unsigned int lock;
 } arch_spinlock_t;
Index: linux-4.19.25-rt16/arch/ia64/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/ia64/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/ia64/include/asm/spinlock_types.h
@@ -2,10 +2,6 @@
 #ifndef _ASM_IA64_SPINLOCK_TYPES_H
 #define _ASM_IA64_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 typedef struct {
 	volatile unsigned int lock;
 } arch_spinlock_t;
Index: linux-4.19.25-rt16/arch/ia64/kernel/mca.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/ia64/kernel/mca.c
+++ linux-4.19.25-rt16/arch/ia64/kernel/mca.c
@@ -1824,7 +1824,7 @@ format_mca_init_stack(void *mca_data, un
 	ti->cpu = cpu;
 	p->stack = ti;
 	p->state = TASK_UNINTERRUPTIBLE;
-	cpumask_set_cpu(cpu, &p->cpus_allowed);
+	cpumask_set_cpu(cpu, &p->cpus_mask);
 	INIT_LIST_HEAD(&p->tasks);
 	p->parent = p->real_parent = p->group_leader = p;
 	INIT_LIST_HEAD(&p->children);
Index: linux-4.19.25-rt16/arch/mips/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/mips/Kconfig
+++ linux-4.19.25-rt16/arch/mips/Kconfig
@@ -2517,7 +2517,7 @@ config MIPS_CRC_SUPPORT
 #
 config HIGHMEM
 	bool "High Memory Support"
-	depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !CPU_MIPS32_3_5_EVA
+	depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !CPU_MIPS32_3_5_EVA && !PREEMPT_RT_FULL
 
 config CPU_SUPPORTS_HIGHMEM
 	bool
Index: linux-4.19.25-rt16/arch/mips/include/asm/switch_to.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/mips/include/asm/switch_to.h
+++ linux-4.19.25-rt16/arch/mips/include/asm/switch_to.h
@@ -42,7 +42,7 @@ extern struct task_struct *ll_task;
  * inline to try to keep the overhead down. If we have been forced to run on
  * a "CPU" with an FPU because of a previous high level of FP computation,
  * but did not actually use the FPU during the most recent time-slice (CU1
- * isn't set), we undo the restriction on cpus_allowed.
+ * isn't set), we undo the restriction on cpus_mask.
  *
  * We're not calling set_cpus_allowed() here, because we have no need to
  * force prompt migration - we're already switching the current CPU to a
@@ -57,7 +57,7 @@ do {									\
 	    test_ti_thread_flag(__prev_ti, TIF_FPUBOUND) &&		\
 	    (!(KSTK_STATUS(prev) & ST0_CU1))) {				\
 		clear_ti_thread_flag(__prev_ti, TIF_FPUBOUND);		\
-		prev->cpus_allowed = prev->thread.user_cpus_allowed;	\
+		prev->cpus_mask = prev->thread.user_cpus_allowed;	\
 	}								\
 	next->thread.emulated_fp = 0;					\
 } while(0)
Index: linux-4.19.25-rt16/arch/mips/kernel/mips-mt-fpaff.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/mips/kernel/mips-mt-fpaff.c
+++ linux-4.19.25-rt16/arch/mips/kernel/mips-mt-fpaff.c
@@ -177,7 +177,7 @@ asmlinkage long mipsmt_sys_sched_getaffi
 	if (retval)
 		goto out_unlock;
 
-	cpumask_or(&allowed, &p->thread.user_cpus_allowed, &p->cpus_allowed);
+	cpumask_or(&allowed, &p->thread.user_cpus_allowed, p->cpus_ptr);
 	cpumask_and(&mask, &allowed, cpu_active_mask);
 
 out_unlock:
Index: linux-4.19.25-rt16/arch/mips/kernel/traps.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/mips/kernel/traps.c
+++ linux-4.19.25-rt16/arch/mips/kernel/traps.c
@@ -1174,12 +1174,12 @@ static void mt_ase_fp_affinity(void)
 		 * restricted the allowed set to exclude any CPUs with FPUs,
 		 * we'll skip the procedure.
 		 */
-		if (cpumask_intersects(&current->cpus_allowed, &mt_fpu_cpumask)) {
+		if (cpumask_intersects(&current->cpus_mask, &mt_fpu_cpumask)) {
 			cpumask_t tmask;
 
 			current->thread.user_cpus_allowed
-				= current->cpus_allowed;
-			cpumask_and(&tmask, &current->cpus_allowed,
+				= current->cpus_mask;
+			cpumask_and(&tmask, &current->cpus_mask,
 				    &mt_fpu_cpumask);
 			set_cpus_allowed_ptr(current, &tmask);
 			set_thread_flag(TIF_FPUBOUND);
Index: linux-4.19.25-rt16/arch/powerpc/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/Kconfig
+++ linux-4.19.25-rt16/arch/powerpc/Kconfig
@@ -105,10 +105,11 @@ config LOCKDEP_SUPPORT
 
 config RWSEM_GENERIC_SPINLOCK
 	bool
+	default y if PREEMPT_RT_FULL
 
 config RWSEM_XCHGADD_ALGORITHM
 	bool
-	default y
+	default y if !PREEMPT_RT_FULL
 
 config GENERIC_LOCKBREAK
 	bool
@@ -215,6 +216,7 @@ config PPC
 	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !HAVE_HARDLOCKUP_DETECTOR_ARCH
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_PREEMPT_LAZY
 	select HAVE_RCU_TABLE_FREE		if SMP
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RELIABLE_STACKTRACE		if PPC64 && CPU_LITTLE_ENDIAN
@@ -397,7 +399,7 @@ menu "Kernel options"
 
 config HIGHMEM
 	bool "High memory support"
-	depends on PPC32
+	depends on PPC32 && !PREEMPT_RT_FULL
 
 source kernel/Kconfig.hz
 
Index: linux-4.19.25-rt16/arch/powerpc/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/powerpc/include/asm/spinlock_types.h
@@ -2,10 +2,6 @@
 #ifndef _ASM_POWERPC_SPINLOCK_TYPES_H
 #define _ASM_POWERPC_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 typedef struct {
 	volatile unsigned int slock;
 } arch_spinlock_t;
Index: linux-4.19.25-rt16/arch/powerpc/include/asm/thread_info.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/include/asm/thread_info.h
+++ linux-4.19.25-rt16/arch/powerpc/include/asm/thread_info.h
@@ -37,6 +37,8 @@ struct thread_info {
 	int		cpu;			/* cpu we're on */
 	int		preempt_count;		/* 0 => preemptable,
 						   <0 => BUG */
+	int		preempt_lazy_count;	/* 0 => preemptable,
+						   <0 => BUG */
 	unsigned long	local_flags;		/* private flags for thread */
 #ifdef CONFIG_LIVEPATCH
 	unsigned long *livepatch_sp;
@@ -81,18 +83,18 @@ extern int arch_dup_task_struct(struct t
 #define TIF_SIGPENDING		1	/* signal pending */
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
 #define TIF_FSCHECK		3	/* Check FS is USER_DS on return */
-#define TIF_32BIT		4	/* 32 bit binary */
 #define TIF_RESTORE_TM		5	/* need to restore TM FP/VEC/VSX */
 #define TIF_PATCH_PENDING	6	/* pending live patching update */
 #define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
 #define TIF_SINGLESTEP		8	/* singlestepping active */
 #define TIF_NOHZ		9	/* in adaptive nohz mode */
 #define TIF_SECCOMP		10	/* secure computing */
-#define TIF_RESTOREALL		11	/* Restore all regs (implies NOERROR) */
-#define TIF_NOERROR		12	/* Force successful syscall return */
+
+#define TIF_NEED_RESCHED_LAZY	11	/* lazy rescheduling necessary */
+#define TIF_SYSCALL_TRACEPOINT	12	/* syscall tracepoint instrumentation */
+
 #define TIF_NOTIFY_RESUME	13	/* callback before returning to user */
 #define TIF_UPROBE		14	/* breakpointed or single-stepping */
-#define TIF_SYSCALL_TRACEPOINT	15	/* syscall tracepoint instrumentation */
 #define TIF_EMULATE_STACK_STORE	16	/* Is an instruction emulation
 						for stack store? */
 #define TIF_MEMDIE		17	/* is terminating due to OOM killer */
@@ -100,6 +102,10 @@ extern int arch_dup_task_struct(struct t
 #define TIF_ELF2ABI		18	/* function descriptors must die! */
 #endif
 #define TIF_POLLING_NRFLAG	19	/* true if poll_idle() is polling TIF_NEED_RESCHED */
+#define TIF_32BIT		20	/* 32 bit binary */
+#define TIF_RESTOREALL		21	/* Restore all regs (implies NOERROR) */
+#define TIF_NOERROR		22	/* Force successful syscall return */
+
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
@@ -119,6 +125,7 @@ extern int arch_dup_task_struct(struct t
 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
 #define _TIF_EMULATE_STACK_STORE	(1<<TIF_EMULATE_STACK_STORE)
 #define _TIF_NOHZ		(1<<TIF_NOHZ)
+#define _TIF_NEED_RESCHED_LAZY	(1<<TIF_NEED_RESCHED_LAZY)
 #define _TIF_FSCHECK		(1<<TIF_FSCHECK)
 #define _TIF_SYSCALL_DOTRACE	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
 				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
@@ -127,8 +134,9 @@ extern int arch_dup_task_struct(struct t
 #define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
 				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
 				 _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
-				 _TIF_FSCHECK)
+				 _TIF_FSCHECK | _TIF_NEED_RESCHED_LAZY)
 #define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)
+#define _TIF_NEED_RESCHED_MASK	(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
 
 /* Bits in local_flags */
 /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
Index: linux-4.19.25-rt16/arch/powerpc/kernel/asm-offsets.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/kernel/asm-offsets.c
+++ linux-4.19.25-rt16/arch/powerpc/kernel/asm-offsets.c
@@ -156,6 +156,7 @@ int main(void)
 	OFFSET(TI_FLAGS, thread_info, flags);
 	OFFSET(TI_LOCAL_FLAGS, thread_info, local_flags);
 	OFFSET(TI_PREEMPT, thread_info, preempt_count);
+	OFFSET(TI_PREEMPT_LAZY, thread_info, preempt_lazy_count);
 	OFFSET(TI_TASK, thread_info, task);
 	OFFSET(TI_CPU, thread_info, cpu);
 
Index: linux-4.19.25-rt16/arch/powerpc/kernel/entry_32.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/kernel/entry_32.S
+++ linux-4.19.25-rt16/arch/powerpc/kernel/entry_32.S
@@ -393,7 +393,9 @@ ret_from_syscall:
 	MTMSRD(r10)
 	lwz	r9,TI_FLAGS(r12)
 	li	r8,-MAX_ERRNO
-	andi.	r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
+	lis	r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@h
+	ori	r0,r0, (_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@l
+	and.	r0,r9,r0
 	bne-	syscall_exit_work
 	cmplw	0,r3,r8
 	blt+	syscall_exit_cont
@@ -511,13 +513,13 @@ syscall_dotrace:
 	b	syscall_dotrace_cont
 
 syscall_exit_work:
-	andi.	r0,r9,_TIF_RESTOREALL
+	andis.	r0,r9,_TIF_RESTOREALL@h
 	beq+	0f
 	REST_NVGPRS(r1)
 	b	2f
 0:	cmplw	0,r3,r8
 	blt+	1f
-	andi.	r0,r9,_TIF_NOERROR
+	andis.	r0,r9,_TIF_NOERROR@h
 	bne-	1f
 	lwz	r11,_CCR(r1)			/* Load CR */
 	neg	r3,r3
@@ -526,12 +528,12 @@ syscall_exit_work:
 
 1:	stw	r6,RESULT(r1)	/* Save result */
 	stw	r3,GPR3(r1)	/* Update return value */
-2:	andi.	r0,r9,(_TIF_PERSYSCALL_MASK)
+2:	andis.	r0,r9,(_TIF_PERSYSCALL_MASK)@h
 	beq	4f
 
 	/* Clear per-syscall TIF flags if any are set.  */
 
-	li	r11,_TIF_PERSYSCALL_MASK
+	lis	r11,_TIF_PERSYSCALL_MASK@h
 	addi	r12,r12,TI_FLAGS
 3:	lwarx	r8,0,r12
 	andc	r8,r8,r11
@@ -888,7 +890,14 @@ resume_kernel:
 	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
 	bne	restore
 	andi.	r8,r8,_TIF_NEED_RESCHED
+	bne+	1f
+	lwz	r0,TI_PREEMPT_LAZY(r9)
+	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
+	bne	restore
+	lwz	r0,TI_FLAGS(r9)
+	andi.	r0,r0,_TIF_NEED_RESCHED_LAZY
 	beq+	restore
+1:
 	lwz	r3,_MSR(r1)
 	andi.	r0,r3,MSR_EE	/* interrupts off? */
 	beq	restore		/* don't schedule if so */
@@ -899,11 +908,11 @@ resume_kernel:
 	 */
 	bl	trace_hardirqs_off
 #endif
-1:	bl	preempt_schedule_irq
+2:	bl	preempt_schedule_irq
 	CURRENT_THREAD_INFO(r9, r1)
 	lwz	r3,TI_FLAGS(r9)
-	andi.	r0,r3,_TIF_NEED_RESCHED
-	bne-	1b
+	andi.	r0,r3,_TIF_NEED_RESCHED_MASK
+	bne-	2b
 #ifdef CONFIG_TRACE_IRQFLAGS
 	/* And now, to properly rebalance the above, we tell lockdep they
 	 * are being turned back on, which will happen when we return
@@ -1232,7 +1241,7 @@ global_dbcr0:
 #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
 
 do_work:			/* r10 contains MSR_KERNEL here */
-	andi.	r0,r9,_TIF_NEED_RESCHED
+	andi.	r0,r9,_TIF_NEED_RESCHED_MASK
 	beq	do_user_signal
 
 do_resched:			/* r10 contains MSR_KERNEL here */
@@ -1253,7 +1262,7 @@ recheck:
 	MTMSRD(r10)		/* disable interrupts */
 	CURRENT_THREAD_INFO(r9, r1)
 	lwz	r9,TI_FLAGS(r9)
-	andi.	r0,r9,_TIF_NEED_RESCHED
+	andi.	r0,r9,_TIF_NEED_RESCHED_MASK
 	bne-	do_resched
 	andi.	r0,r9,_TIF_USER_WORK_MASK
 	beq	restore_user
Index: linux-4.19.25-rt16/arch/powerpc/kernel/entry_64.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/kernel/entry_64.S
+++ linux-4.19.25-rt16/arch/powerpc/kernel/entry_64.S
@@ -176,7 +176,7 @@ system_call:			/* label this so stack tr
  * based on caller's run-mode / personality.
  */
 	ld	r11,SYS_CALL_TABLE@toc(2)
-	andi.	r10,r10,_TIF_32BIT
+	andis.	r10,r10,_TIF_32BIT@h
 	beq	15f
 	addi	r11,r11,8	/* use 32-bit syscall entries */
 	clrldi	r3,r3,32
@@ -250,7 +250,9 @@ system_call_exit:
 
 	ld	r9,TI_FLAGS(r12)
 	li	r11,-MAX_ERRNO
-	andi.	r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
+	lis	r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@h
+	ori	r0,r0,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)@l
+	and.	r0,r9,r0
 	bne-	.Lsyscall_exit_work
 
 	andi.	r0,r8,MSR_FP
@@ -363,25 +365,25 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	/* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr.
 	 If TIF_NOERROR is set, just save r3 as it is. */
 
-	andi.	r0,r9,_TIF_RESTOREALL
+	andis.	r0,r9,_TIF_RESTOREALL@h
 	beq+	0f
 	REST_NVGPRS(r1)
 	b	2f
 0:	cmpld	r3,r11		/* r11 is -MAX_ERRNO */
 	blt+	1f
-	andi.	r0,r9,_TIF_NOERROR
+	andis.	r0,r9,_TIF_NOERROR@h
 	bne-	1f
 	ld	r5,_CCR(r1)
 	neg	r3,r3
 	oris	r5,r5,0x1000	/* Set SO bit in CR */
 	std	r5,_CCR(r1)
 1:	std	r3,GPR3(r1)
-2:	andi.	r0,r9,(_TIF_PERSYSCALL_MASK)
+2:	andis.	r0,r9,(_TIF_PERSYSCALL_MASK)@h
 	beq	4f
 
 	/* Clear per-syscall TIF flags if any are set.  */
 
-	li	r11,_TIF_PERSYSCALL_MASK
+	lis	r11,(_TIF_PERSYSCALL_MASK)@h
 	addi	r12,r12,TI_FLAGS
 3:	ldarx	r10,0,r12
 	andc	r10,r10,r11
@@ -768,7 +770,7 @@ _GLOBAL(ret_from_except_lite)
 	bl	restore_math
 	b	restore
 #endif
-1:	andi.	r0,r4,_TIF_NEED_RESCHED
+1:	andi.	r0,r4,_TIF_NEED_RESCHED_MASK
 	beq	2f
 	bl	restore_interrupts
 	SCHEDULE_USER
@@ -830,10 +832,18 @@ resume_kernel:
 
 #ifdef CONFIG_PREEMPT
 	/* Check if we need to preempt */
+	lwz	r8,TI_PREEMPT(r9)
+	cmpwi	0,r8,0		/* if non-zero, just restore regs and return */
+	bne	restore
 	andi.	r0,r4,_TIF_NEED_RESCHED
+	bne+	check_count
+
+	andi.	r0,r4,_TIF_NEED_RESCHED_LAZY
 	beq+	restore
+	lwz	r8,TI_PREEMPT_LAZY(r9)
+
 	/* Check that preempt_count() == 0 and interrupts are enabled */
-	lwz	r8,TI_PREEMPT(r9)
+check_count:
 	cmpwi	cr0,r8,0
 	bne	restore
 	ld	r0,SOFTE(r1)
@@ -850,7 +860,7 @@ resume_kernel:
 	/* Re-test flags and eventually loop */
 	CURRENT_THREAD_INFO(r9, r1)
 	ld	r4,TI_FLAGS(r9)
-	andi.	r0,r4,_TIF_NEED_RESCHED
+	andi.	r0,r4,_TIF_NEED_RESCHED_MASK
 	bne	1b
 
 	/*
Index: linux-4.19.25-rt16/arch/powerpc/kernel/irq.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/kernel/irq.c
+++ linux-4.19.25-rt16/arch/powerpc/kernel/irq.c
@@ -766,6 +766,7 @@ void irq_ctx_init(void)
 	}
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void do_softirq_own_stack(void)
 {
 	struct thread_info *curtp, *irqtp;
@@ -783,6 +784,7 @@ void do_softirq_own_stack(void)
 	if (irqtp->flags)
 		set_bits(irqtp->flags, &curtp->flags);
 }
+#endif
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
 {
Index: linux-4.19.25-rt16/arch/powerpc/kernel/misc_32.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/kernel/misc_32.S
+++ linux-4.19.25-rt16/arch/powerpc/kernel/misc_32.S
@@ -42,6 +42,7 @@
  * We store the saved ksp_limit in the unused part
  * of the STACK_FRAME_OVERHEAD
  */
+#ifndef CONFIG_PREEMPT_RT_FULL
 _GLOBAL(call_do_softirq)
 	mflr	r0
 	stw	r0,4(r1)
@@ -58,6 +59,7 @@ _GLOBAL(call_do_softirq)
 	stw	r10,THREAD+KSP_LIMIT(r2)
 	mtlr	r0
 	blr
+#endif
 
 /*
  * void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
Index: linux-4.19.25-rt16/arch/powerpc/kernel/misc_64.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/kernel/misc_64.S
+++ linux-4.19.25-rt16/arch/powerpc/kernel/misc_64.S
@@ -32,6 +32,7 @@
 
 	.text
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 _GLOBAL(call_do_softirq)
 	mflr	r0
 	std	r0,16(r1)
@@ -42,6 +43,7 @@ _GLOBAL(call_do_softirq)
 	ld	r0,16(r1)
 	mtlr	r0
 	blr
+#endif
 
 _GLOBAL(call_do_irq)
 	mflr	r0
Index: linux-4.19.25-rt16/arch/powerpc/kvm/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/kvm/Kconfig
+++ linux-4.19.25-rt16/arch/powerpc/kvm/Kconfig
@@ -178,6 +178,7 @@ config KVM_E500MC
 config KVM_MPIC
 	bool "KVM in-kernel MPIC emulation"
 	depends on KVM && E500
+	depends on !PREEMPT_RT_FULL
 	select HAVE_KVM_IRQCHIP
 	select HAVE_KVM_IRQFD
 	select HAVE_KVM_IRQ_ROUTING
Index: linux-4.19.25-rt16/arch/powerpc/platforms/cell/spufs/sched.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/platforms/cell/spufs/sched.c
+++ linux-4.19.25-rt16/arch/powerpc/platforms/cell/spufs/sched.c
@@ -141,7 +141,7 @@ void __spu_update_sched_info(struct spu_
 	 * runqueue. The context will be rescheduled on the proper node
 	 * if it is timesliced or preempted.
 	 */
-	cpumask_copy(&ctx->cpus_allowed, &current->cpus_allowed);
+	cpumask_copy(&ctx->cpus_allowed, current->cpus_ptr);
 
 	/* Save the current cpu id for spu interrupt routing. */
 	ctx->last_ran = raw_smp_processor_id();
Index: linux-4.19.25-rt16/arch/powerpc/platforms/ps3/device-init.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/platforms/ps3/device-init.c
+++ linux-4.19.25-rt16/arch/powerpc/platforms/ps3/device-init.c
@@ -752,8 +752,8 @@ static int ps3_notification_read_write(s
 	}
 	pr_debug("%s:%u: notification %s issued\n", __func__, __LINE__, op);
 
-	res = wait_event_interruptible(dev->done.wait,
-				       dev->done.done || kthread_should_stop());
+	res = swait_event_interruptible_exclusive(dev->done.wait,
+						  dev->done.done || kthread_should_stop());
 	if (kthread_should_stop())
 		res = -EINTR;
 	if (res) {
Index: linux-4.19.25-rt16/arch/powerpc/platforms/pseries/iommu.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/powerpc/platforms/pseries/iommu.c
+++ linux-4.19.25-rt16/arch/powerpc/platforms/pseries/iommu.c
@@ -38,6 +38,7 @@
 #include <linux/of.h>
 #include <linux/iommu.h>
 #include <linux/rculist.h>
+#include <linux/locallock.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/rtas.h>
@@ -212,6 +213,7 @@ static int tce_build_pSeriesLP(struct io
 }
 
 static DEFINE_PER_CPU(__be64 *, tce_page);
+static DEFINE_LOCAL_IRQ_LOCK(tcp_page_lock);
 
 static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
 				     long npages, unsigned long uaddr,
@@ -232,7 +234,8 @@ static int tce_buildmulti_pSeriesLP(stru
 		                           direction, attrs);
 	}
 
-	local_irq_save(flags);	/* to protect tcep and the page behind it */
+	/* to protect tcep and the page behind it */
+	local_lock_irqsave(tcp_page_lock, flags);
 
 	tcep = __this_cpu_read(tce_page);
 
@@ -243,7 +246,7 @@ static int tce_buildmulti_pSeriesLP(stru
 		tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
 		/* If allocation fails, fall back to the loop implementation */
 		if (!tcep) {
-			local_irq_restore(flags);
+			local_unlock_irqrestore(tcp_page_lock, flags);
 			return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
 					    direction, attrs);
 		}
@@ -277,7 +280,7 @@ static int tce_buildmulti_pSeriesLP(stru
 		tcenum += limit;
 	} while (npages > 0 && !rc);
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(tcp_page_lock, flags);
 
 	if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
 		ret = (int)rc;
@@ -435,13 +438,14 @@ static int tce_setrange_multi_pSeriesLP(
 	u64 rc = 0;
 	long l, limit;
 
-	local_irq_disable();	/* to protect tcep and the page behind it */
+	/* to protect tcep and the page behind it */
+	local_lock_irq(tcp_page_lock);
 	tcep = __this_cpu_read(tce_page);
 
 	if (!tcep) {
 		tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
 		if (!tcep) {
-			local_irq_enable();
+			local_unlock_irq(tcp_page_lock);
 			return -ENOMEM;
 		}
 		__this_cpu_write(tce_page, tcep);
@@ -487,7 +491,7 @@ static int tce_setrange_multi_pSeriesLP(
 
 	/* error cleanup: caller will clear whole range */
 
-	local_irq_enable();
+	local_unlock_irq(tcp_page_lock);
 	return rc;
 }
 
Index: linux-4.19.25-rt16/arch/s390/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/s390/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/s390/include/asm/spinlock_types.h
@@ -2,10 +2,6 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 typedef struct {
 	int lock;
 } __attribute__ ((aligned (4))) arch_spinlock_t;
Index: linux-4.19.25-rt16/arch/sh/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/sh/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/sh/include/asm/spinlock_types.h
@@ -2,10 +2,6 @@
 #ifndef __ASM_SH_SPINLOCK_TYPES_H
 #define __ASM_SH_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 typedef struct {
 	volatile unsigned int lock;
 } arch_spinlock_t;
Index: linux-4.19.25-rt16/arch/sh/kernel/irq.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/sh/kernel/irq.c
+++ linux-4.19.25-rt16/arch/sh/kernel/irq.c
@@ -148,6 +148,7 @@ void irq_ctx_exit(int cpu)
 	hardirq_ctx[cpu] = NULL;
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void do_softirq_own_stack(void)
 {
 	struct thread_info *curctx;
@@ -175,6 +176,7 @@ void do_softirq_own_stack(void)
 		  "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
 	);
 }
+#endif
 #else
 static inline void handle_one_irq(unsigned int irq)
 {
Index: linux-4.19.25-rt16/arch/sparc/kernel/irq_64.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/sparc/kernel/irq_64.c
+++ linux-4.19.25-rt16/arch/sparc/kernel/irq_64.c
@@ -854,6 +854,7 @@ void __irq_entry handler_irq(int pil, st
 	set_irq_regs(old_regs);
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void do_softirq_own_stack(void)
 {
 	void *orig_sp, *sp = softirq_stack[smp_processor_id()];
@@ -868,6 +869,7 @@ void do_softirq_own_stack(void)
 	__asm__ __volatile__("mov %0, %%sp"
 			     : : "r" (orig_sp));
 }
+#endif
 
 #ifdef CONFIG_HOTPLUG_CPU
 void fixup_irqs(void)
Index: linux-4.19.25-rt16/arch/x86/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/Kconfig
+++ linux-4.19.25-rt16/arch/x86/Kconfig
@@ -180,6 +180,7 @@ config X86
 	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_PREEMPT_LAZY
 	select HAVE_RCU_TABLE_FREE		if PARAVIRT
 	select HAVE_RCU_TABLE_INVALIDATE	if HAVE_RCU_TABLE_FREE
 	select HAVE_REGS_AND_STACK_ACCESS_API
@@ -264,8 +265,11 @@ config ARCH_MAY_HAVE_PC_FDC
 	def_bool y
 	depends on ISA_DMA_API
 
+config RWSEM_GENERIC_SPINLOCK
+	def_bool PREEMPT_RT_FULL
+
 config RWSEM_XCHGADD_ALGORITHM
-	def_bool y
+	def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL
 
 config GENERIC_CALIBRATE_DELAY
 	def_bool y
@@ -934,7 +938,7 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 config MAXSMP
 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 	depends on X86_64 && SMP && DEBUG_KERNEL
-	select CPUMASK_OFFSTACK
+	select CPUMASK_OFFSTACK if !PREEMPT_RT_FULL
 	---help---
 	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
 	  If unsure, say N.
Index: linux-4.19.25-rt16/arch/x86/crypto/aesni-intel_glue.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/crypto/aesni-intel_glue.c
+++ linux-4.19.25-rt16/arch/x86/crypto/aesni-intel_glue.c
@@ -434,14 +434,14 @@ static int ecb_encrypt(struct skcipher_r
 
 	err = skcipher_walk_virt(&walk, req, true);
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
+		kernel_fpu_begin();
 		aesni_ecb_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 			      nbytes & AES_BLOCK_MASK);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = skcipher_walk_done(&walk, nbytes);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
@@ -456,14 +456,14 @@ static int ecb_decrypt(struct skcipher_r
 
 	err = skcipher_walk_virt(&walk, req, true);
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
+		kernel_fpu_begin();
 		aesni_ecb_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 			      nbytes & AES_BLOCK_MASK);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = skcipher_walk_done(&walk, nbytes);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
@@ -478,14 +478,14 @@ static int cbc_encrypt(struct skcipher_r
 
 	err = skcipher_walk_virt(&walk, req, true);
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
+		kernel_fpu_begin();
 		aesni_cbc_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 			      nbytes & AES_BLOCK_MASK, walk.iv);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = skcipher_walk_done(&walk, nbytes);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
@@ -500,14 +500,14 @@ static int cbc_decrypt(struct skcipher_r
 
 	err = skcipher_walk_virt(&walk, req, true);
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
+		kernel_fpu_begin();
 		aesni_cbc_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 			      nbytes & AES_BLOCK_MASK, walk.iv);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = skcipher_walk_done(&walk, nbytes);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
@@ -557,18 +557,20 @@ static int ctr_crypt(struct skcipher_req
 
 	err = skcipher_walk_virt(&walk, req, true);
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
+		kernel_fpu_begin();
 		aesni_ctr_enc_tfm(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 			              nbytes & AES_BLOCK_MASK, walk.iv);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = skcipher_walk_done(&walk, nbytes);
 	}
 	if (walk.nbytes) {
+		kernel_fpu_begin();
 		ctr_crypt_final(ctx, &walk);
+		kernel_fpu_end();
 		err = skcipher_walk_done(&walk, 0);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
Index: linux-4.19.25-rt16/arch/x86/crypto/cast5_avx_glue.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/crypto/cast5_avx_glue.c
+++ linux-4.19.25-rt16/arch/x86/crypto/cast5_avx_glue.c
@@ -61,7 +61,7 @@ static inline void cast5_fpu_end(bool fp
 
 static int ecb_crypt(struct skcipher_request *req, bool enc)
 {
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct skcipher_walk walk;
@@ -76,7 +76,7 @@ static int ecb_crypt(struct skcipher_req
 		u8 *wsrc = walk.src.virt.addr;
 		u8 *wdst = walk.dst.virt.addr;
 
-		fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes);
+		fpu_enabled = cast5_fpu_begin(false, &walk, nbytes);
 
 		/* Process multi-block batch */
 		if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) {
@@ -105,10 +105,9 @@ static int ecb_crypt(struct skcipher_req
 		} while (nbytes >= bsize);
 
 done:
+		cast5_fpu_end(fpu_enabled);
 		err = skcipher_walk_done(&walk, nbytes);
 	}
-
-	cast5_fpu_end(fpu_enabled);
 	return err;
 }
 
@@ -212,7 +211,7 @@ static int cbc_decrypt(struct skcipher_r
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm);
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct skcipher_walk walk;
 	unsigned int nbytes;
 	int err;
@@ -220,12 +219,11 @@ static int cbc_decrypt(struct skcipher_r
 	err = skcipher_walk_virt(&walk, req, false);
 
 	while ((nbytes = walk.nbytes)) {
-		fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes);
+		fpu_enabled = cast5_fpu_begin(false, &walk, nbytes);
 		nbytes = __cbc_decrypt(ctx, &walk);
+		cast5_fpu_end(fpu_enabled);
 		err = skcipher_walk_done(&walk, nbytes);
 	}
-
-	cast5_fpu_end(fpu_enabled);
 	return err;
 }
 
@@ -292,7 +290,7 @@ static int ctr_crypt(struct skcipher_req
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct cast5_ctx *ctx = crypto_skcipher_ctx(tfm);
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct skcipher_walk walk;
 	unsigned int nbytes;
 	int err;
@@ -300,13 +298,12 @@ static int ctr_crypt(struct skcipher_req
 	err = skcipher_walk_virt(&walk, req, false);
 
 	while ((nbytes = walk.nbytes) >= CAST5_BLOCK_SIZE) {
-		fpu_enabled = cast5_fpu_begin(fpu_enabled, &walk, nbytes);
+		fpu_enabled = cast5_fpu_begin(false, &walk, nbytes);
 		nbytes = __ctr_crypt(&walk, ctx);
+		cast5_fpu_end(fpu_enabled);
 		err = skcipher_walk_done(&walk, nbytes);
 	}
 
-	cast5_fpu_end(fpu_enabled);
-
 	if (walk.nbytes) {
 		ctr_crypt_final(&walk, ctx);
 		err = skcipher_walk_done(&walk, 0);
Index: linux-4.19.25-rt16/arch/x86/crypto/chacha20_glue.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/crypto/chacha20_glue.c
+++ linux-4.19.25-rt16/arch/x86/crypto/chacha20_glue.c
@@ -81,23 +81,24 @@ static int chacha20_simd(struct skcipher
 
 	crypto_chacha20_init(state, ctx, walk.iv);
 
-	kernel_fpu_begin();
-
 	while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
+		kernel_fpu_begin();
+
 		chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr,
 				rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE));
+		kernel_fpu_end();
 		err = skcipher_walk_done(&walk,
 					 walk.nbytes % CHACHA20_BLOCK_SIZE);
 	}
 
 	if (walk.nbytes) {
+		kernel_fpu_begin();
 		chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr,
 				walk.nbytes);
+		kernel_fpu_end();
 		err = skcipher_walk_done(&walk, 0);
 	}
 
-	kernel_fpu_end();
-
 	return err;
 }
 
Index: linux-4.19.25-rt16/arch/x86/crypto/glue_helper.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/crypto/glue_helper.c
+++ linux-4.19.25-rt16/arch/x86/crypto/glue_helper.c
@@ -38,7 +38,7 @@ int glue_ecb_req_128bit(const struct com
 	void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
 	const unsigned int bsize = 128 / 8;
 	struct skcipher_walk walk;
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	unsigned int nbytes;
 	int err;
 
@@ -51,7 +51,7 @@ int glue_ecb_req_128bit(const struct com
 		unsigned int i;
 
 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
-					     &walk, fpu_enabled, nbytes);
+					     &walk, false, nbytes);
 		for (i = 0; i < gctx->num_funcs; i++) {
 			func_bytes = bsize * gctx->funcs[i].num_blocks;
 
@@ -69,10 +69,9 @@ int glue_ecb_req_128bit(const struct com
 			if (nbytes < bsize)
 				break;
 		}
+		glue_fpu_end(fpu_enabled);
 		err = skcipher_walk_done(&walk, nbytes);
 	}
-
-	glue_fpu_end(fpu_enabled);
 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_ecb_req_128bit);
@@ -115,7 +114,7 @@ int glue_cbc_decrypt_req_128bit(const st
 	void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
 	const unsigned int bsize = 128 / 8;
 	struct skcipher_walk walk;
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	unsigned int nbytes;
 	int err;
 
@@ -129,7 +128,7 @@ int glue_cbc_decrypt_req_128bit(const st
 		u128 last_iv;
 
 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
-					     &walk, fpu_enabled, nbytes);
+					     &walk, false, nbytes);
 		/* Start of the last block. */
 		src += nbytes / bsize - 1;
 		dst += nbytes / bsize - 1;
@@ -161,10 +160,10 @@ int glue_cbc_decrypt_req_128bit(const st
 done:
 		u128_xor(dst, dst, (u128 *)walk.iv);
 		*(u128 *)walk.iv = last_iv;
+		glue_fpu_end(fpu_enabled);
 		err = skcipher_walk_done(&walk, nbytes);
 	}
 
-	glue_fpu_end(fpu_enabled);
 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_cbc_decrypt_req_128bit);
@@ -175,7 +174,7 @@ int glue_ctr_req_128bit(const struct com
 	void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
 	const unsigned int bsize = 128 / 8;
 	struct skcipher_walk walk;
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	unsigned int nbytes;
 	int err;
 
@@ -189,7 +188,7 @@ int glue_ctr_req_128bit(const struct com
 		le128 ctrblk;
 
 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
-					     &walk, fpu_enabled, nbytes);
+					     &walk, false, nbytes);
 
 		be128_to_le128(&ctrblk, (be128 *)walk.iv);
 
@@ -213,11 +212,10 @@ int glue_ctr_req_128bit(const struct com
 		}
 
 		le128_to_be128((be128 *)walk.iv, &ctrblk);
+		glue_fpu_end(fpu_enabled);
 		err = skcipher_walk_done(&walk, nbytes);
 	}
 
-	glue_fpu_end(fpu_enabled);
-
 	if (nbytes) {
 		le128 ctrblk;
 		u128 tmp;
@@ -278,7 +276,7 @@ int glue_xts_req_128bit(const struct com
 {
 	const unsigned int bsize = 128 / 8;
 	struct skcipher_walk walk;
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	unsigned int nbytes;
 	int err;
 
@@ -289,21 +287,24 @@ int glue_xts_req_128bit(const struct com
 
 	/* set minimum length to bsize, for tweak_fn */
 	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
-				     &walk, fpu_enabled,
+				     &walk, false,
 				     nbytes < bsize ? bsize : nbytes);
 
 	/* calculate first value of T */
 	tweak_fn(tweak_ctx, walk.iv, walk.iv);
 
 	while (nbytes) {
+		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
+					     &walk, fpu_enabled,
+					     nbytes < bsize ? bsize : nbytes);
 		nbytes = __glue_xts_req_128bit(gctx, crypt_ctx, &walk);
 
+		glue_fpu_end(fpu_enabled);
+		fpu_enabled = false;
 		err = skcipher_walk_done(&walk, nbytes);
 		nbytes = walk.nbytes;
 	}
 
-	glue_fpu_end(fpu_enabled);
-
 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_xts_req_128bit);
Index: linux-4.19.25-rt16/arch/x86/entry/common.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/entry/common.c
+++ linux-4.19.25-rt16/arch/x86/entry/common.c
@@ -133,7 +133,7 @@ static long syscall_trace_enter(struct p
 
 #define EXIT_TO_USERMODE_LOOP_FLAGS				\
 	(_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_UPROBE |	\
-	 _TIF_NEED_RESCHED | _TIF_USER_RETURN_NOTIFY | _TIF_PATCH_PENDING)
+	 _TIF_NEED_RESCHED_MASK | _TIF_USER_RETURN_NOTIFY | _TIF_PATCH_PENDING)
 
 static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags)
 {
@@ -148,9 +148,16 @@ static void exit_to_usermode_loop(struct
 		/* We have work to do. */
 		local_irq_enable();
 
-		if (cached_flags & _TIF_NEED_RESCHED)
+		if (cached_flags & _TIF_NEED_RESCHED_MASK)
 			schedule();
 
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+		if (unlikely(current->forced_info.si_signo)) {
+			struct task_struct *t = current;
+			force_sig_info(t->forced_info.si_signo, &t->forced_info, t);
+			t->forced_info.si_signo = 0;
+		}
+#endif
 		if (cached_flags & _TIF_UPROBE)
 			uprobe_notify_resume(regs);
 
Index: linux-4.19.25-rt16/arch/x86/entry/entry_32.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/entry/entry_32.S
+++ linux-4.19.25-rt16/arch/x86/entry/entry_32.S
@@ -764,8 +764,25 @@ END(ret_from_exception)
 ENTRY(resume_kernel)
 	DISABLE_INTERRUPTS(CLBR_ANY)
 .Lneed_resched:
+	# preempt count == 0 + NEED_RS set?
 	cmpl	$0, PER_CPU_VAR(__preempt_count)
+#ifndef CONFIG_PREEMPT_LAZY
 	jnz	restore_all_kernel
+#else
+	jz	test_int_off
+
+	# atleast preempt count == 0 ?
+	cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count)
+	jne	restore_all_kernel
+
+	movl	PER_CPU_VAR(current_task), %ebp
+	cmpl	$0,TASK_TI_preempt_lazy_count(%ebp)	# non-zero preempt_lazy_count ?
+	jnz	restore_all_kernel
+
+	testl	$_TIF_NEED_RESCHED_LAZY, TASK_TI_flags(%ebp)
+	jz	restore_all_kernel
+test_int_off:
+#endif
 	testl	$X86_EFLAGS_IF, PT_EFLAGS(%esp)	# interrupts off (exception path) ?
 	jz	restore_all_kernel
 	call	preempt_schedule_irq
Index: linux-4.19.25-rt16/arch/x86/entry/entry_64.S
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/entry/entry_64.S
+++ linux-4.19.25-rt16/arch/x86/entry/entry_64.S
@@ -706,7 +706,23 @@ retint_kernel:
 	btl	$9, EFLAGS(%rsp)		/* were interrupts off? */
 	jnc	1f
 0:	cmpl	$0, PER_CPU_VAR(__preempt_count)
+#ifndef CONFIG_PREEMPT_LAZY
 	jnz	1f
+#else
+	jz	do_preempt_schedule_irq
+
+	# atleast preempt count == 0 ?
+	cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count)
+	jnz	1f
+
+	movq	PER_CPU_VAR(current_task), %rcx
+	cmpl	$0, TASK_TI_preempt_lazy_count(%rcx)
+	jnz	1f
+
+	btl	$TIF_NEED_RESCHED_LAZY,TASK_TI_flags(%rcx)
+	jnc	1f
+do_preempt_schedule_irq:
+#endif
 	call	preempt_schedule_irq
 	jmp	0b
 1:
@@ -1043,6 +1059,7 @@ bad_gs:
 	jmp	2b
 	.previous
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /* Call softirq on interrupt stack. Interrupts are off. */
 ENTRY(do_softirq_own_stack)
 	pushq	%rbp
@@ -1053,6 +1070,7 @@ ENTRY(do_softirq_own_stack)
 	leaveq
 	ret
 ENDPROC(do_softirq_own_stack)
+#endif
 
 #ifdef CONFIG_XEN
 idtentry hypervisor_callback xen_do_hypervisor_callback has_error_code=0
Index: linux-4.19.25-rt16/arch/x86/include/asm/fpu/api.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/include/asm/fpu/api.h
+++ linux-4.19.25-rt16/arch/x86/include/asm/fpu/api.h
@@ -25,6 +25,7 @@ extern void __kernel_fpu_begin(void);
 extern void __kernel_fpu_end(void);
 extern void kernel_fpu_begin(void);
 extern void kernel_fpu_end(void);
+extern void kernel_fpu_resched(void);
 extern bool irq_fpu_usable(void);
 
 /*
Index: linux-4.19.25-rt16/arch/x86/include/asm/preempt.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/include/asm/preempt.h
+++ linux-4.19.25-rt16/arch/x86/include/asm/preempt.h
@@ -86,17 +86,46 @@ static __always_inline void __preempt_co
  * a decrement which hits zero means we have no preempt_count and should
  * reschedule.
  */
-static __always_inline bool __preempt_count_dec_and_test(void)
+static __always_inline bool ____preempt_count_dec_and_test(void)
 {
 	GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), e);
 }
 
+static __always_inline bool __preempt_count_dec_and_test(void)
+{
+	if (____preempt_count_dec_and_test())
+		return true;
+#ifdef CONFIG_PREEMPT_LAZY
+	if (current_thread_info()->preempt_lazy_count)
+		return false;
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+#else
+	return false;
+#endif
+}
+
 /*
  * Returns true when we need to resched and can (barring IRQ state).
  */
 static __always_inline bool should_resched(int preempt_offset)
 {
+#ifdef CONFIG_PREEMPT_LAZY
+	u32 tmp;
+
+	tmp = raw_cpu_read_4(__preempt_count);
+	if (tmp == preempt_offset)
+		return true;
+
+	/* preempt count == 0 ? */
+	tmp &= ~PREEMPT_NEED_RESCHED;
+	if (tmp != preempt_offset)
+		return false;
+	if (current_thread_info()->preempt_lazy_count)
+		return false;
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+#else
 	return unlikely(raw_cpu_read_4(__preempt_count) == preempt_offset);
+#endif
 }
 
 #ifdef CONFIG_PREEMPT
Index: linux-4.19.25-rt16/arch/x86/include/asm/signal.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/include/asm/signal.h
+++ linux-4.19.25-rt16/arch/x86/include/asm/signal.h
@@ -28,6 +28,19 @@ typedef struct {
 #define SA_IA32_ABI	0x02000000u
 #define SA_X32_ABI	0x01000000u
 
+/*
+ * Because some traps use the IST stack, we must keep preemption
+ * disabled while calling do_trap(), but do_trap() may call
+ * force_sig_info() which will grab the signal spin_locks for the
+ * task, which in PREEMPT_RT_FULL are mutexes.  By defining
+ * ARCH_RT_DELAYS_SIGNAL_SEND the force_sig_info() will set
+ * TIF_NOTIFY_RESUME and set up the signal to be sent on exit of the
+ * trap.
+ */
+#if defined(CONFIG_PREEMPT_RT_FULL)
+#define ARCH_RT_DELAYS_SIGNAL_SEND
+#endif
+
 #ifndef CONFIG_COMPAT
 typedef sigset_t compat_sigset_t;
 #endif
Index: linux-4.19.25-rt16/arch/x86/include/asm/stackprotector.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/include/asm/stackprotector.h
+++ linux-4.19.25-rt16/arch/x86/include/asm/stackprotector.h
@@ -60,7 +60,7 @@
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	u64 canary;
+	u64 uninitialized_var(canary);
 	u64 tsc;
 
 #ifdef CONFIG_X86_64
@@ -71,8 +71,14 @@ static __always_inline void boot_init_st
 	 * of randomness. The TSC only matters for very early init,
 	 * there it already has some randomness on most systems. Later
 	 * on during the bootup the random pool has true entropy too.
+	 * For preempt-rt we need to weaken the randomness a bit, as
+	 * we can't call into the random generator from atomic context
+	 * due to locking constraints. We just leave canary
+	 * uninitialized and use the TSC based randomness on top of it.
 	 */
+#ifndef CONFIG_PREEMPT_RT_FULL
 	get_random_bytes(&canary, sizeof(canary));
+#endif
 	tsc = rdtsc();
 	canary += tsc + (tsc << 32UL);
 	canary &= CANARY_MASK;
Index: linux-4.19.25-rt16/arch/x86/include/asm/thread_info.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/include/asm/thread_info.h
+++ linux-4.19.25-rt16/arch/x86/include/asm/thread_info.h
@@ -56,17 +56,24 @@ struct task_struct;
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	u32			status;		/* thread synchronous flags */
+	int			preempt_lazy_count;	/* 0 => lazy preemptable
+							  <0 => BUG */
 };
 
 #define INIT_THREAD_INFO(tsk)			\
 {						\
 	.flags		= 0,			\
+	.preempt_lazy_count = 0,		\
 }
 
 #else /* !__ASSEMBLY__ */
 
 #include <asm/asm-offsets.h>
 
+#define GET_THREAD_INFO(reg) \
+	_ASM_MOV PER_CPU_VAR(cpu_current_top_of_stack),reg ; \
+	_ASM_SUB $(THREAD_SIZE),reg ;
+
 #endif
 
 /*
@@ -91,6 +98,7 @@ struct thread_info {
 #define TIF_NOCPUID		15	/* CPUID is not accessible in userland */
 #define TIF_NOTSC		16	/* TSC is not accessible in userland */
 #define TIF_IA32		17	/* IA32 compatibility process */
+#define TIF_NEED_RESCHED_LAZY	18	/* lazy rescheduling necessary */
 #define TIF_NOHZ		19	/* in adaptive nohz mode */
 #define TIF_MEMDIE		20	/* is terminating due to OOM killer */
 #define TIF_POLLING_NRFLAG	21	/* idle is polling for TIF_NEED_RESCHED */
@@ -120,6 +128,7 @@ struct thread_info {
 #define _TIF_NOCPUID		(1 << TIF_NOCPUID)
 #define _TIF_NOTSC		(1 << TIF_NOTSC)
 #define _TIF_IA32		(1 << TIF_IA32)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 #define _TIF_NOHZ		(1 << TIF_NOHZ)
 #define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 #define _TIF_IO_BITMAP		(1 << TIF_IO_BITMAP)
@@ -165,6 +174,8 @@ struct thread_info {
 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
 
+#define _TIF_NEED_RESCHED_MASK	(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
+
 #define STACK_WARN		(THREAD_SIZE/8)
 
 /*
Index: linux-4.19.25-rt16/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-4.19.25-rt16/arch/x86/kernel/apic/io_apic.c
@@ -1722,19 +1722,20 @@ static bool io_apic_level_ack_pending(st
 	return false;
 }
 
-static inline bool ioapic_irqd_mask(struct irq_data *data)
+static inline bool ioapic_prepare_move(struct irq_data *data)
 {
 	/* If we are moving the irq we need to mask it */
 	if (unlikely(irqd_is_setaffinity_pending(data))) {
-		mask_ioapic_irq(data);
+		if (!irqd_irq_masked(data))
+			mask_ioapic_irq(data);
 		return true;
 	}
 	return false;
 }
 
-static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked)
+static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
 {
-	if (unlikely(masked)) {
+	if (unlikely(moveit)) {
 		/* Only migrate the irq if the ack has been received.
 		 *
 		 * On rare occasions the broadcast level triggered ack gets
@@ -1763,15 +1764,17 @@ static inline void ioapic_irqd_unmask(st
 		 */
 		if (!io_apic_level_ack_pending(data->chip_data))
 			irq_move_masked_irq(data);
-		unmask_ioapic_irq(data);
+		/* If the irq is masked in the core, leave it */
+		if (!irqd_irq_masked(data))
+			unmask_ioapic_irq(data);
 	}
 }
 #else
-static inline bool ioapic_irqd_mask(struct irq_data *data)
+static inline bool ioapic_prepare_move(struct irq_data *data)
 {
 	return false;
 }
-static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked)
+static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
 {
 }
 #endif
@@ -1780,11 +1783,11 @@ static void ioapic_ack_level(struct irq_
 {
 	struct irq_cfg *cfg = irqd_cfg(irq_data);
 	unsigned long v;
-	bool masked;
+	bool moveit;
 	int i;
 
 	irq_complete_move(cfg);
-	masked = ioapic_irqd_mask(irq_data);
+	moveit = ioapic_prepare_move(irq_data);
 
 	/*
 	 * It appears there is an erratum which affects at least version 0x11
@@ -1839,7 +1842,7 @@ static void ioapic_ack_level(struct irq_
 		eoi_ioapic_pin(cfg->vector, irq_data->chip_data);
 	}
 
-	ioapic_irqd_unmask(irq_data, masked);
+	ioapic_finish_move(irq_data, moveit);
 }
 
 static void ioapic_ir_ack_level(struct irq_data *irq_data)
Index: linux-4.19.25-rt16/arch/x86/kernel/asm-offsets.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kernel/asm-offsets.c
+++ linux-4.19.25-rt16/arch/x86/kernel/asm-offsets.c
@@ -38,6 +38,7 @@ void common(void) {
 
 	BLANK();
 	OFFSET(TASK_TI_flags, task_struct, thread_info.flags);
+	OFFSET(TASK_TI_preempt_lazy_count, task_struct, thread_info.preempt_lazy_count);
 	OFFSET(TASK_addr_limit, task_struct, thread.addr_limit);
 
 	BLANK();
@@ -94,6 +95,7 @@ void common(void) {
 
 	BLANK();
 	DEFINE(PTREGS_SIZE, sizeof(struct pt_regs));
+	DEFINE(_PREEMPT_ENABLED, PREEMPT_ENABLED);
 
 	/* TLB state for the entry code */
 	OFFSET(TLB_STATE_user_pcid_flush_mask, tlb_state, user_pcid_flush_mask);
Index: linux-4.19.25-rt16/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
+++ linux-4.19.25-rt16/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
@@ -1435,7 +1435,7 @@ static int pseudo_lock_dev_mmap(struct f
 	 * may be scheduled elsewhere and invalidate entries in the
 	 * pseudo-locked region.
 	 */
-	if (!cpumask_subset(&current->cpus_allowed, &plr->d->cpu_mask)) {
+	if (!cpumask_subset(current->cpus_ptr, &plr->d->cpu_mask)) {
 		mutex_unlock(&rdtgroup_mutex);
 		return -EINVAL;
 	}
Index: linux-4.19.25-rt16/arch/x86/kernel/fpu/core.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kernel/fpu/core.c
+++ linux-4.19.25-rt16/arch/x86/kernel/fpu/core.c
@@ -138,6 +138,18 @@ void kernel_fpu_end(void)
 }
 EXPORT_SYMBOL_GPL(kernel_fpu_end);
 
+void kernel_fpu_resched(void)
+{
+	WARN_ON_FPU(!this_cpu_read(in_kernel_fpu));
+
+	if (should_resched(PREEMPT_OFFSET)) {
+		kernel_fpu_end();
+		cond_resched();
+		kernel_fpu_begin();
+	}
+}
+EXPORT_SYMBOL_GPL(kernel_fpu_resched);
+
 /*
  * Save the FPU state (mark it for reload if necessary):
  *
Index: linux-4.19.25-rt16/arch/x86/kernel/fpu/signal.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kernel/fpu/signal.c
+++ linux-4.19.25-rt16/arch/x86/kernel/fpu/signal.c
@@ -344,10 +344,12 @@ static int __fpu__restore_sig(void __use
 			sanitize_restored_xstate(tsk, &env, xfeatures, fx_only);
 		}
 
+		preempt_disable();
 		local_bh_disable();
 		fpu->initialized = 1;
 		fpu__restore(fpu);
 		local_bh_enable();
+		preempt_enable();
 
 		return err;
 	} else {
Index: linux-4.19.25-rt16/arch/x86/kernel/irq_32.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kernel/irq_32.c
+++ linux-4.19.25-rt16/arch/x86/kernel/irq_32.c
@@ -130,6 +130,7 @@ void irq_ctx_init(int cpu)
 	       cpu, per_cpu(hardirq_stack, cpu),  per_cpu(softirq_stack, cpu));
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void do_softirq_own_stack(void)
 {
 	struct irq_stack *irqstk;
@@ -146,6 +147,7 @@ void do_softirq_own_stack(void)
 
 	call_on_stack(__do_softirq, isp);
 }
+#endif
 
 bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
 {
Index: linux-4.19.25-rt16/arch/x86/kernel/process_32.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kernel/process_32.c
+++ linux-4.19.25-rt16/arch/x86/kernel/process_32.c
@@ -38,6 +38,7 @@
 #include <linux/io.h>
 #include <linux/kdebug.h>
 #include <linux/syscalls.h>
+#include <linux/highmem.h>
 
 #include <asm/pgtable.h>
 #include <asm/ldt.h>
@@ -198,6 +199,35 @@ start_thread(struct pt_regs *regs, unsig
 }
 EXPORT_SYMBOL_GPL(start_thread);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p)
+{
+	int i;
+
+	/*
+	 * Clear @prev's kmap_atomic mappings
+	 */
+	for (i = 0; i < prev_p->kmap_idx; i++) {
+		int idx = i + KM_TYPE_NR * smp_processor_id();
+		pte_t *ptep = kmap_pte - idx;
+
+		kpte_clear_flush(ptep, __fix_to_virt(FIX_KMAP_BEGIN + idx));
+	}
+	/*
+	 * Restore @next_p's kmap_atomic mappings
+	 */
+	for (i = 0; i < next_p->kmap_idx; i++) {
+		int idx = i + KM_TYPE_NR * smp_processor_id();
+
+		if (!pte_none(next_p->kmap_pte[i]))
+			set_pte(kmap_pte - idx, next_p->kmap_pte[i]);
+	}
+}
+#else
+static inline void
+switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { }
+#endif
+
 
 /*
  *	switch_to(x,y) should switch tasks from x to y.
@@ -267,6 +297,8 @@ __switch_to(struct task_struct *prev_p,
 
 	switch_to_extra(prev_p, next_p);
 
+	switch_kmaps(prev_p, next_p);
+
 	/*
 	 * Leave lazy mode, flushing any hypercalls made here.
 	 * This must be done before restoring TLS segments so
Index: linux-4.19.25-rt16/arch/x86/kvm/lapic.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kvm/lapic.c
+++ linux-4.19.25-rt16/arch/x86/kvm/lapic.c
@@ -2250,7 +2250,7 @@ int kvm_create_lapic(struct kvm_vcpu *vc
 	apic->vcpu = vcpu;
 
 	hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
-		     HRTIMER_MODE_ABS_PINNED);
+		     HRTIMER_MODE_ABS_PINNED_HARD);
 	apic->lapic_timer.timer.function = apic_timer_fn;
 
 	/*
Index: linux-4.19.25-rt16/arch/x86/kvm/x86.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/kvm/x86.c
+++ linux-4.19.25-rt16/arch/x86/kvm/x86.c
@@ -6725,6 +6725,13 @@ int kvm_arch_init(void *opaque)
 		goto out;
 	}
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
+		printk(KERN_ERR "RT requires X86_FEATURE_CONSTANT_TSC\n");
+		return -EOPNOTSUPP;
+	}
+#endif
+
 	r = kvm_mmu_module_init();
 	if (r)
 		goto out_free_percpu;
Index: linux-4.19.25-rt16/arch/x86/mm/highmem_32.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/mm/highmem_32.c
+++ linux-4.19.25-rt16/arch/x86/mm/highmem_32.c
@@ -32,10 +32,11 @@ EXPORT_SYMBOL(kunmap);
  */
 void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 {
+	pte_t pte = mk_pte(page, prot);
 	unsigned long vaddr;
 	int idx, type;
 
-	preempt_disable();
+	preempt_disable_nort();
 	pagefault_disable();
 
 	if (!PageHighMem(page))
@@ -45,7 +46,10 @@ void *kmap_atomic_prot(struct page *page
 	idx = type + KM_TYPE_NR*smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
 	BUG_ON(!pte_none(*(kmap_pte-idx)));
-	set_pte(kmap_pte-idx, mk_pte(page, prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+	current->kmap_pte[type] = pte;
+#endif
+	set_pte(kmap_pte-idx, pte);
 	arch_flush_lazy_mmu_mode();
 
 	return (void *)vaddr;
@@ -88,6 +92,9 @@ void __kunmap_atomic(void *kvaddr)
 		 * is a bad idea also, in case the page changes cacheability
 		 * attributes or becomes a protected page in a hypervisor.
 		 */
+#ifdef CONFIG_PREEMPT_RT_FULL
+		current->kmap_pte[type] = __pte(0);
+#endif
 		kpte_clear_flush(kmap_pte-idx, vaddr);
 		kmap_atomic_idx_pop();
 		arch_flush_lazy_mmu_mode();
@@ -100,7 +107,7 @@ void __kunmap_atomic(void *kvaddr)
 #endif
 
 	pagefault_enable();
-	preempt_enable();
+	preempt_enable_nort();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
Index: linux-4.19.25-rt16/arch/x86/mm/iomap_32.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/mm/iomap_32.c
+++ linux-4.19.25-rt16/arch/x86/mm/iomap_32.c
@@ -59,6 +59,7 @@ EXPORT_SYMBOL_GPL(iomap_free);
 
 void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
 {
+	pte_t pte = pfn_pte(pfn, prot);
 	unsigned long vaddr;
 	int idx, type;
 
@@ -68,7 +69,12 @@ void *kmap_atomic_prot_pfn(unsigned long
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR * smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-	set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
+	WARN_ON(!pte_none(*(kmap_pte - idx)));
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+	current->kmap_pte[type] = pte;
+#endif
+	set_pte(kmap_pte - idx, pte);
 	arch_flush_lazy_mmu_mode();
 
 	return (void *)vaddr;
@@ -119,6 +125,9 @@ iounmap_atomic(void __iomem *kvaddr)
 		 * is a bad idea also, in case the page changes cacheability
 		 * attributes or becomes a protected page in a hypervisor.
 		 */
+#ifdef CONFIG_PREEMPT_RT_FULL
+		current->kmap_pte[type] = __pte(0);
+#endif
 		kpte_clear_flush(kmap_pte-idx, vaddr);
 		kmap_atomic_idx_pop();
 	}
Index: linux-4.19.25-rt16/arch/x86/mm/pageattr.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/mm/pageattr.c
+++ linux-4.19.25-rt16/arch/x86/mm/pageattr.c
@@ -688,11 +688,17 @@ __split_large_page(struct cpa_data *cpa,
 
 	spin_lock(&pgd_lock);
 	/*
+	 * Keep preemption disabled after __flush_tlb_all() which expects not be
+	 * preempted during the flush of the local TLB.
+	 */
+	preempt_disable();
+	/*
 	 * Check for races, another CPU might have split this page
 	 * up for us already:
 	 */
 	tmp = _lookup_address_cpa(cpa, address, &level);
 	if (tmp != kpte) {
+		preempt_enable();
 		spin_unlock(&pgd_lock);
 		return 1;
 	}
@@ -726,6 +732,7 @@ __split_large_page(struct cpa_data *cpa,
 		break;
 
 	default:
+		preempt_enable();
 		spin_unlock(&pgd_lock);
 		return 1;
 	}
@@ -764,6 +771,7 @@ __split_large_page(struct cpa_data *cpa,
 	 * going on.
 	 */
 	__flush_tlb_all();
+	preempt_enable();
 	spin_unlock(&pgd_lock);
 
 	return 0;
Index: linux-4.19.25-rt16/arch/x86/platform/efi/efi_64.c
===================================================================
--- linux-4.19.25-rt16.orig/arch/x86/platform/efi/efi_64.c
+++ linux-4.19.25-rt16/arch/x86/platform/efi/efi_64.c
@@ -619,18 +619,16 @@ void __init efi_dump_pagetable(void)
 
 /*
  * Makes the calling thread switch to/from efi_mm context. Can be used
- * for SetVirtualAddressMap() i.e. current->active_mm == init_mm as well
- * as during efi runtime calls i.e current->active_mm == current_mm.
- * We are not mm_dropping()/mm_grabbing() any mm, because we are not
- * losing/creating any references.
+ * in a kernel thread and user context. Preemption needs to remain disabled
+ * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
+ * can not change under us.
+ * It should be ensured that there are no concurent calls to this function.
  */
 void efi_switch_mm(struct mm_struct *mm)
 {
-	task_lock(current);
 	efi_scratch.prev_mm = current->active_mm;
 	current->active_mm = mm;
 	switch_mm(efi_scratch.prev_mm, mm, NULL);
-	task_unlock(current);
 }
 
 #ifdef CONFIG_EFI_MIXED
Index: linux-4.19.25-rt16/arch/xtensa/include/asm/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/arch/xtensa/include/asm/spinlock_types.h
+++ linux-4.19.25-rt16/arch/xtensa/include/asm/spinlock_types.h
@@ -2,10 +2,6 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 typedef struct {
 	volatile unsigned int slock;
 } arch_spinlock_t;
Index: linux-4.19.25-rt16/block/blk-core.c
===================================================================
--- linux-4.19.25-rt16.orig/block/blk-core.c
+++ linux-4.19.25-rt16/block/blk-core.c
@@ -189,6 +189,9 @@ void blk_rq_init(struct request_queue *q
 
 	INIT_LIST_HEAD(&rq->queuelist);
 	INIT_LIST_HEAD(&rq->timeout_list);
+#ifdef CONFIG_PREEMPT_RT_FULL
+	INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work);
+#endif
 	rq->cpu = -1;
 	rq->q = q;
 	rq->__sector = (sector_t) -1;
@@ -965,12 +968,21 @@ void blk_queue_exit(struct request_queue
 	percpu_ref_put(&q->q_usage_counter);
 }
 
+static void blk_queue_usage_counter_release_swork(struct swork_event *sev)
+{
+	struct request_queue *q =
+		container_of(sev, struct request_queue, mq_pcpu_wake);
+
+	wake_up_all(&q->mq_freeze_wq);
+}
+
 static void blk_queue_usage_counter_release(struct percpu_ref *ref)
 {
 	struct request_queue *q =
 		container_of(ref, struct request_queue, q_usage_counter);
 
-	wake_up_all(&q->mq_freeze_wq);
+	if (wq_has_sleeper(&q->mq_freeze_wq))
+		swork_queue(&q->mq_pcpu_wake);
 }
 
 static void blk_rq_timed_out_timer(struct timer_list *t)
@@ -1063,6 +1075,7 @@ struct request_queue *blk_alloc_queue_no
 	queue_flag_set_unlocked(QUEUE_FLAG_BYPASS, q);
 
 	init_waitqueue_head(&q->mq_freeze_wq);
+	INIT_SWORK(&q->mq_pcpu_wake, blk_queue_usage_counter_release_swork);
 
 	/*
 	 * Init percpu_ref in atomic mode so that it's faster to shutdown.
@@ -3953,6 +3966,8 @@ int __init blk_dev_init(void)
 	if (!kblockd_workqueue)
 		panic("Failed to create kblockd\n");
 
+	BUG_ON(swork_get());
+
 	request_cachep = kmem_cache_create("blkdev_requests",
 			sizeof(struct request), 0, SLAB_PANIC, NULL);
 
Index: linux-4.19.25-rt16/block/blk-ioc.c
===================================================================
--- linux-4.19.25-rt16.orig/block/blk-ioc.c
+++ linux-4.19.25-rt16/block/blk-ioc.c
@@ -9,6 +9,7 @@
 #include <linux/blkdev.h>
 #include <linux/slab.h>
 #include <linux/sched/task.h>
+#include <linux/delay.h>
 
 #include "blk.h"
 
@@ -118,7 +119,7 @@ static void ioc_release_fn(struct work_s
 			spin_unlock(q->queue_lock);
 		} else {
 			spin_unlock_irqrestore(&ioc->lock, flags);
-			cpu_relax();
+			cpu_chill();
 			spin_lock_irqsave_nested(&ioc->lock, flags, 1);
 		}
 	}
@@ -202,7 +203,7 @@ retry:
 				spin_unlock(icq->q->queue_lock);
 			} else {
 				spin_unlock_irqrestore(&ioc->lock, flags);
-				cpu_relax();
+				cpu_chill();
 				goto retry;
 			}
 		}
Index: linux-4.19.25-rt16/block/blk-mq.c
===================================================================
--- linux-4.19.25-rt16.orig/block/blk-mq.c
+++ linux-4.19.25-rt16/block/blk-mq.c
@@ -320,6 +320,9 @@ static struct request *blk_mq_rq_ctx_ini
 	rq->extra_len = 0;
 	rq->__deadline = 0;
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work);
+#endif
 	INIT_LIST_HEAD(&rq->timeout_list);
 	rq->timeout = 0;
 
@@ -547,12 +550,24 @@ void blk_mq_end_request(struct request *
 }
 EXPORT_SYMBOL(blk_mq_end_request);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+
+void __blk_mq_complete_request_remote_work(struct work_struct *work)
+{
+	struct request *rq = container_of(work, struct request, work);
+
+	rq->q->softirq_done_fn(rq);
+}
+
+#else
+
 static void __blk_mq_complete_request_remote(void *data)
 {
 	struct request *rq = data;
 
 	rq->q->softirq_done_fn(rq);
 }
+#endif
 
 static void __blk_mq_complete_request(struct request *rq)
 {
@@ -570,19 +585,27 @@ static void __blk_mq_complete_request(st
 		return;
 	}
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
 		shared = cpus_share_cache(cpu, ctx->cpu);
 
 	if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
+#ifdef CONFIG_PREEMPT_RT_FULL
+		/*
+		 * We could force QUEUE_FLAG_SAME_FORCE then we would not get in
+		 * here. But we could try to invoke it one the CPU like this.
+		 */
+		schedule_work_on(ctx->cpu, &rq->work);
+#else
 		rq->csd.func = __blk_mq_complete_request_remote;
 		rq->csd.info = rq;
 		rq->csd.flags = 0;
 		smp_call_function_single_async(ctx->cpu, &rq->csd);
+#endif
 	} else {
 		rq->q->softirq_done_fn(rq);
 	}
-	put_cpu();
+	put_cpu_light();
 }
 
 static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx)
@@ -1368,14 +1391,14 @@ static void __blk_mq_delay_run_hw_queue(
 		return;
 
 	if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
-		int cpu = get_cpu();
+		int cpu = get_cpu_light();
 		if (cpumask_test_cpu(cpu, hctx->cpumask)) {
 			__blk_mq_run_hw_queue(hctx);
-			put_cpu();
+			put_cpu_light();
 			return;
 		}
 
-		put_cpu();
+		put_cpu_light();
 	}
 
 	kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work,
@@ -3124,10 +3147,9 @@ static bool blk_mq_poll_hybrid_sleep(str
 	kt = nsecs;
 
 	mode = HRTIMER_MODE_REL;
-	hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode);
+	hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode, current);
 	hrtimer_set_expires(&hs.timer, kt);
 
-	hrtimer_init_sleeper(&hs, current);
 	do {
 		if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE)
 			break;
Index: linux-4.19.25-rt16/block/blk-mq.h
===================================================================
--- linux-4.19.25-rt16.orig/block/blk-mq.h
+++ linux-4.19.25-rt16/block/blk-mq.h
@@ -113,12 +113,12 @@ static inline struct blk_mq_ctx *__blk_m
  */
 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 {
-	return __blk_mq_get_ctx(q, get_cpu());
+	return __blk_mq_get_ctx(q, get_cpu_light());
 }
 
 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 {
-	put_cpu();
+	put_cpu_light();
 }
 
 struct blk_mq_alloc_data {
Index: linux-4.19.25-rt16/block/blk-softirq.c
===================================================================
--- linux-4.19.25-rt16.orig/block/blk-softirq.c
+++ linux-4.19.25-rt16/block/blk-softirq.c
@@ -53,6 +53,7 @@ static void trigger_softirq(void *data)
 		raise_softirq_irqoff(BLOCK_SOFTIRQ);
 
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 
 /*
@@ -91,6 +92,7 @@ static int blk_softirq_cpu_dead(unsigned
 			 this_cpu_ptr(&blk_cpu_done));
 	raise_softirq_irqoff(BLOCK_SOFTIRQ);
 	local_irq_enable();
+	preempt_check_resched_rt();
 
 	return 0;
 }
@@ -143,6 +145,7 @@ do_local:
 		goto do_local;
 
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 EXPORT_SYMBOL(__blk_complete_request);
 
Index: linux-4.19.25-rt16/crypto/cryptd.c
===================================================================
--- linux-4.19.25-rt16.orig/crypto/cryptd.c
+++ linux-4.19.25-rt16/crypto/cryptd.c
@@ -39,6 +39,7 @@ MODULE_PARM_DESC(cryptd_max_cpu_qlen, "S
 struct cryptd_cpu_queue {
 	struct crypto_queue queue;
 	struct work_struct work;
+	spinlock_t qlock;
 };
 
 struct cryptd_queue {
@@ -117,6 +118,7 @@ static int cryptd_init_queue(struct cryp
 		cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
 		crypto_init_queue(&cpu_queue->queue, max_cpu_qlen);
 		INIT_WORK(&cpu_queue->work, cryptd_queue_worker);
+		spin_lock_init(&cpu_queue->qlock);
 	}
 	pr_info("cryptd: max_cpu_qlen set to %d\n", max_cpu_qlen);
 	return 0;
@@ -141,8 +143,10 @@ static int cryptd_enqueue_request(struct
 	struct cryptd_cpu_queue *cpu_queue;
 	atomic_t *refcnt;
 
-	cpu = get_cpu();
-	cpu_queue = this_cpu_ptr(queue->cpu_queue);
+	cpu_queue = raw_cpu_ptr(queue->cpu_queue);
+	spin_lock_bh(&cpu_queue->qlock);
+	cpu = smp_processor_id();
+
 	err = crypto_enqueue_request(&cpu_queue->queue, request);
 
 	refcnt = crypto_tfm_ctx(request->tfm);
@@ -158,7 +162,7 @@ static int cryptd_enqueue_request(struct
 	atomic_inc(refcnt);
 
 out_put_cpu:
-	put_cpu();
+	spin_unlock_bh(&cpu_queue->qlock);
 
 	return err;
 }
@@ -174,16 +178,11 @@ static void cryptd_queue_worker(struct w
 	cpu_queue = container_of(work, struct cryptd_cpu_queue, work);
 	/*
 	 * Only handle one request at a time to avoid hogging crypto workqueue.
-	 * preempt_disable/enable is used to prevent being preempted by
-	 * cryptd_enqueue_request(). local_bh_disable/enable is used to prevent
-	 * cryptd_enqueue_request() being accessed from software interrupts.
 	 */
-	local_bh_disable();
-	preempt_disable();
+	spin_lock_bh(&cpu_queue->qlock);
 	backlog = crypto_get_backlog(&cpu_queue->queue);
 	req = crypto_dequeue_request(&cpu_queue->queue);
-	preempt_enable();
-	local_bh_enable();
+	spin_unlock_bh(&cpu_queue->qlock);
 
 	if (!req)
 		return;
Index: linux-4.19.25-rt16/crypto/scompress.c
===================================================================
--- linux-4.19.25-rt16.orig/crypto/scompress.c
+++ linux-4.19.25-rt16/crypto/scompress.c
@@ -24,6 +24,7 @@
 #include <linux/cryptouser.h>
 #include <net/netlink.h>
 #include <linux/scatterlist.h>
+#include <linux/locallock.h>
 #include <crypto/scatterwalk.h>
 #include <crypto/internal/acompress.h>
 #include <crypto/internal/scompress.h>
@@ -34,6 +35,7 @@ static void * __percpu *scomp_src_scratc
 static void * __percpu *scomp_dst_scratches;
 static int scomp_scratch_users;
 static DEFINE_MUTEX(scomp_lock);
+static DEFINE_LOCAL_IRQ_LOCK(scomp_scratches_lock);
 
 #ifdef CONFIG_NET
 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
@@ -146,7 +148,7 @@ static int scomp_acomp_comp_decomp(struc
 	void **tfm_ctx = acomp_tfm_ctx(tfm);
 	struct crypto_scomp *scomp = *tfm_ctx;
 	void **ctx = acomp_request_ctx(req);
-	const int cpu = get_cpu();
+	const int cpu = local_lock_cpu(scomp_scratches_lock);
 	u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
 	u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
 	int ret;
@@ -181,7 +183,7 @@ static int scomp_acomp_comp_decomp(struc
 					 1);
 	}
 out:
-	put_cpu();
+	local_unlock_cpu(scomp_scratches_lock);
 	return ret;
 }
 
Index: linux-4.19.25-rt16/drivers/block/zram/zcomp.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/block/zram/zcomp.c
+++ linux-4.19.25-rt16/drivers/block/zram/zcomp.c
@@ -116,12 +116,20 @@ ssize_t zcomp_available_show(const char
 
 struct zcomp_strm *zcomp_stream_get(struct zcomp *comp)
 {
-	return *get_cpu_ptr(comp->stream);
+	struct zcomp_strm *zstrm;
+
+	zstrm = *get_local_ptr(comp->stream);
+	spin_lock(&zstrm->zcomp_lock);
+	return zstrm;
 }
 
 void zcomp_stream_put(struct zcomp *comp)
 {
-	put_cpu_ptr(comp->stream);
+	struct zcomp_strm *zstrm;
+
+	zstrm = *this_cpu_ptr(comp->stream);
+	spin_unlock(&zstrm->zcomp_lock);
+	put_local_ptr(zstrm);
 }
 
 int zcomp_compress(struct zcomp_strm *zstrm,
@@ -171,6 +179,7 @@ int zcomp_cpu_up_prepare(unsigned int cp
 		pr_err("Can't allocate a compression stream\n");
 		return -ENOMEM;
 	}
+	spin_lock_init(&zstrm->zcomp_lock);
 	*per_cpu_ptr(comp->stream, cpu) = zstrm;
 	return 0;
 }
Index: linux-4.19.25-rt16/drivers/block/zram/zcomp.h
===================================================================
--- linux-4.19.25-rt16.orig/drivers/block/zram/zcomp.h
+++ linux-4.19.25-rt16/drivers/block/zram/zcomp.h
@@ -14,6 +14,7 @@ struct zcomp_strm {
 	/* compression/decompression buffer */
 	void *buffer;
 	struct crypto_comp *tfm;
+	spinlock_t zcomp_lock;
 };
 
 /* dynamic per-device compression frontend */
Index: linux-4.19.25-rt16/drivers/block/zram/zram_drv.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/block/zram/zram_drv.c
+++ linux-4.19.25-rt16/drivers/block/zram/zram_drv.c
@@ -53,6 +53,40 @@ static size_t huge_class_size;
 
 static void zram_free_page(struct zram *zram, size_t index);
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages)
+{
+	size_t index;
+
+	for (index = 0; index < num_pages; index++)
+		spin_lock_init(&zram->table[index].lock);
+}
+
+static int zram_slot_trylock(struct zram *zram, u32 index)
+{
+	int ret;
+
+	ret = spin_trylock(&zram->table[index].lock);
+	if (ret)
+		__set_bit(ZRAM_LOCK, &zram->table[index].value);
+	return ret;
+}
+
+static void zram_slot_lock(struct zram *zram, u32 index)
+{
+	spin_lock(&zram->table[index].lock);
+	__set_bit(ZRAM_LOCK, &zram->table[index].value);
+}
+
+static void zram_slot_unlock(struct zram *zram, u32 index)
+{
+	__clear_bit(ZRAM_LOCK, &zram->table[index].value);
+	spin_unlock(&zram->table[index].lock);
+}
+
+#else
+static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) { }
+
 static int zram_slot_trylock(struct zram *zram, u32 index)
 {
 	return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].value);
@@ -67,6 +101,7 @@ static void zram_slot_unlock(struct zram
 {
 	bit_spin_unlock(ZRAM_LOCK, &zram->table[index].value);
 }
+#endif
 
 static inline bool init_done(struct zram *zram)
 {
@@ -900,6 +935,8 @@ static DEVICE_ATTR_RO(io_stat);
 static DEVICE_ATTR_RO(mm_stat);
 static DEVICE_ATTR_RO(debug_stat);
 
+
+
 static void zram_meta_free(struct zram *zram, u64 disksize)
 {
 	size_t num_pages = disksize >> PAGE_SHIFT;
@@ -930,6 +967,7 @@ static bool zram_meta_alloc(struct zram
 
 	if (!huge_class_size)
 		huge_class_size = zs_huge_class_size(zram->mem_pool);
+	zram_meta_init_table_locks(zram, num_pages);
 	return true;
 }
 
@@ -988,6 +1026,7 @@ static int __zram_bvec_read(struct zram
 	unsigned long handle;
 	unsigned int size;
 	void *src, *dst;
+	struct zcomp_strm *zstrm;
 
 	if (zram_wb_enabled(zram)) {
 		zram_slot_lock(zram, index);
@@ -1022,6 +1061,7 @@ static int __zram_bvec_read(struct zram
 
 	size = zram_get_obj_size(zram, index);
 
+	zstrm = zcomp_stream_get(zram->comp);
 	src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
 	if (size == PAGE_SIZE) {
 		dst = kmap_atomic(page);
@@ -1029,14 +1069,13 @@ static int __zram_bvec_read(struct zram
 		kunmap_atomic(dst);
 		ret = 0;
 	} else {
-		struct zcomp_strm *zstrm = zcomp_stream_get(zram->comp);
 
 		dst = kmap_atomic(page);
 		ret = zcomp_decompress(zstrm, src, size, dst);
 		kunmap_atomic(dst);
-		zcomp_stream_put(zram->comp);
 	}
 	zs_unmap_object(zram->mem_pool, handle);
+	zcomp_stream_put(zram->comp);
 	zram_slot_unlock(zram, index);
 
 	/* Should NEVER happen. Return bio error if it does. */
Index: linux-4.19.25-rt16/drivers/block/zram/zram_drv.h
===================================================================
--- linux-4.19.25-rt16.orig/drivers/block/zram/zram_drv.h
+++ linux-4.19.25-rt16/drivers/block/zram/zram_drv.h
@@ -61,6 +61,9 @@ struct zram_table_entry {
 		unsigned long element;
 	};
 	unsigned long value;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	spinlock_t lock;
+#endif
 #ifdef CONFIG_ZRAM_MEMORY_TRACKING
 	ktime_t ac_time;
 #endif
Index: linux-4.19.25-rt16/drivers/char/random.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/char/random.c
+++ linux-4.19.25-rt16/drivers/char/random.c
@@ -265,6 +265,7 @@
 #include <linux/syscalls.h>
 #include <linux/completion.h>
 #include <linux/uuid.h>
+#include <linux/locallock.h>
 #include <crypto/chacha20.h>
 
 #include <asm/processor.h>
@@ -1229,28 +1230,27 @@ static __u32 get_reg(struct fast_pool *f
 	return *ptr;
 }
 
-void add_interrupt_randomness(int irq, int irq_flags)
+void add_interrupt_randomness(int irq, int irq_flags, __u64 ip)
 {
 	struct entropy_store	*r;
 	struct fast_pool	*fast_pool = this_cpu_ptr(&irq_randomness);
-	struct pt_regs		*regs = get_irq_regs();
 	unsigned long		now = jiffies;
 	cycles_t		cycles = random_get_entropy();
 	__u32			c_high, j_high;
-	__u64			ip;
 	unsigned long		seed;
 	int			credit = 0;
 
 	if (cycles == 0)
-		cycles = get_reg(fast_pool, regs);
+		cycles = get_reg(fast_pool, NULL);
 	c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0;
 	j_high = (sizeof(now) > 4) ? now >> 32 : 0;
 	fast_pool->pool[0] ^= cycles ^ j_high ^ irq;
 	fast_pool->pool[1] ^= now ^ c_high;
-	ip = regs ? instruction_pointer(regs) : _RET_IP_;
+	if (!ip)
+		ip = _RET_IP_;
 	fast_pool->pool[2] ^= ip;
 	fast_pool->pool[3] ^= (sizeof(ip) > 4) ? ip >> 32 :
-		get_reg(fast_pool, regs);
+		get_reg(fast_pool, NULL);
 
 	fast_mix(fast_pool);
 	add_interrupt_bench(cycles);
@@ -2224,6 +2224,7 @@ static rwlock_t batched_entropy_reset_lo
  * at any point prior.
  */
 static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u64);
+static DEFINE_LOCAL_IRQ_LOCK(batched_entropy_u64_lock);
 u64 get_random_u64(void)
 {
 	u64 ret;
@@ -2244,7 +2245,7 @@ u64 get_random_u64(void)
 	warn_unseeded_randomness(&previous);
 
 	use_lock = READ_ONCE(crng_init) < 2;
-	batch = &get_cpu_var(batched_entropy_u64);
+	batch = &get_locked_var(batched_entropy_u64_lock, batched_entropy_u64);
 	if (use_lock)
 		read_lock_irqsave(&batched_entropy_reset_lock, flags);
 	if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) {
@@ -2254,12 +2255,13 @@ u64 get_random_u64(void)
 	ret = batch->entropy_u64[batch->position++];
 	if (use_lock)
 		read_unlock_irqrestore(&batched_entropy_reset_lock, flags);
-	put_cpu_var(batched_entropy_u64);
+	put_locked_var(batched_entropy_u64_lock, batched_entropy_u64);
 	return ret;
 }
 EXPORT_SYMBOL(get_random_u64);
 
 static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u32);
+static DEFINE_LOCAL_IRQ_LOCK(batched_entropy_u32_lock);
 u32 get_random_u32(void)
 {
 	u32 ret;
@@ -2274,7 +2276,7 @@ u32 get_random_u32(void)
 	warn_unseeded_randomness(&previous);
 
 	use_lock = READ_ONCE(crng_init) < 2;
-	batch = &get_cpu_var(batched_entropy_u32);
+	batch = &get_locked_var(batched_entropy_u32_lock, batched_entropy_u32);
 	if (use_lock)
 		read_lock_irqsave(&batched_entropy_reset_lock, flags);
 	if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) {
@@ -2284,7 +2286,7 @@ u32 get_random_u32(void)
 	ret = batch->entropy_u32[batch->position++];
 	if (use_lock)
 		read_unlock_irqrestore(&batched_entropy_reset_lock, flags);
-	put_cpu_var(batched_entropy_u32);
+	put_locked_var(batched_entropy_u32_lock, batched_entropy_u32);
 	return ret;
 }
 EXPORT_SYMBOL(get_random_u32);
Index: linux-4.19.25-rt16/drivers/char/tpm/tpm_tis.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/char/tpm/tpm_tis.c
+++ linux-4.19.25-rt16/drivers/char/tpm/tpm_tis.c
@@ -53,6 +53,31 @@ static inline struct tpm_tis_tcg_phy *to
 	return container_of(data, struct tpm_tis_tcg_phy, priv);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Flushes previous write operations to chip so that a subsequent
+ * ioread*()s won't stall a cpu.
+ */
+static inline void tpm_tis_flush(void __iomem *iobase)
+{
+	ioread8(iobase + TPM_ACCESS(0));
+}
+#else
+#define tpm_tis_flush(iobase) do { } while (0)
+#endif
+
+static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr)
+{
+	iowrite8(b, iobase + addr);
+	tpm_tis_flush(iobase);
+}
+
+static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr)
+{
+	iowrite32(b, iobase + addr);
+	tpm_tis_flush(iobase);
+}
+
 static bool interrupts = true;
 module_param(interrupts, bool, 0444);
 MODULE_PARM_DESC(interrupts, "Enable interrupts");
@@ -150,7 +175,7 @@ static int tpm_tcg_write_bytes(struct tp
 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 
 	while (len--)
-		iowrite8(*value++, phy->iobase + addr);
+		tpm_tis_iowrite8(*value++, phy->iobase, addr);
 
 	return 0;
 }
@@ -177,7 +202,7 @@ static int tpm_tcg_write32(struct tpm_ti
 {
 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 
-	iowrite32(value, phy->iobase + addr);
+	tpm_tis_iowrite32(value, phy->iobase, addr);
 
 	return 0;
 }
Index: linux-4.19.25-rt16/drivers/clocksource/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/drivers/clocksource/Kconfig
+++ linux-4.19.25-rt16/drivers/clocksource/Kconfig
@@ -403,8 +403,11 @@ config ARMV7M_SYSTICK
 	  This options enables support for the ARMv7M system timer unit
 
 config ATMEL_PIT
+	bool "Microchip ARM Periodic Interval Timer (PIT)" if COMPILE_TEST
 	select TIMER_OF if OF
-	def_bool SOC_AT91SAM9 || SOC_SAMA5
+	help
+	  This enables build of clocksource and clockevent driver for
+	  the integrated PIT in Microchip ARM SoCs.
 
 config ATMEL_ST
 	bool "Atmel ST timer support" if COMPILE_TEST
@@ -414,6 +417,14 @@ config ATMEL_ST
 	help
 	  Support for the Atmel ST timer.
 
+config ATMEL_ARM_TCB_CLKSRC
+	bool "Microchip ARM TC Block" if COMPILE_TEST
+	select REGMAP_MMIO
+	depends on GENERIC_CLOCKEVENTS
+	help
+	  This enables build of clocksource and clockevent driver for
+	  the integrated Timer Counter Blocks in Microchip ARM SoCs.
+
 config CLKSRC_EXYNOS_MCT
 	bool "Exynos multi core timer driver" if COMPILE_TEST
 	depends on ARM || ARM64
Index: linux-4.19.25-rt16/drivers/clocksource/Makefile
===================================================================
--- linux-4.19.25-rt16.orig/drivers/clocksource/Makefile
+++ linux-4.19.25-rt16/drivers/clocksource/Makefile
@@ -3,7 +3,8 @@ obj-$(CONFIG_TIMER_OF)		+= timer-of.o
 obj-$(CONFIG_TIMER_PROBE)	+= timer-probe.o
 obj-$(CONFIG_ATMEL_PIT)		+= timer-atmel-pit.o
 obj-$(CONFIG_ATMEL_ST)		+= timer-atmel-st.o
-obj-$(CONFIG_ATMEL_TCB_CLKSRC)	+= tcb_clksrc.o
+obj-$(CONFIG_ATMEL_TCB_CLKSRC) += tcb_clksrc.o
+obj-$(CONFIG_ATMEL_ARM_TCB_CLKSRC)	+= timer-atmel-tcb.o
 obj-$(CONFIG_X86_PM_TIMER)	+= acpi_pm.o
 obj-$(CONFIG_SCx200HR_TIMER)	+= scx200_hrt.o
 obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC)	+= cs5535-clockevt.o
Index: linux-4.19.25-rt16/drivers/clocksource/tcb_clksrc.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/clocksource/tcb_clksrc.c
+++ linux-4.19.25-rt16/drivers/clocksource/tcb_clksrc.c
@@ -25,8 +25,7 @@
  *     this 32 bit free-running counter. the second channel is not used.
  *
  *   - The third channel may be used to provide a 16-bit clockevent
- *     source, used in either periodic or oneshot mode.  This runs
- *     at 32 KiHZ, and can handle delays of up to two seconds.
+ *     source, used in either periodic or oneshot mode.
  *
  * A boot clocksource and clockevent source are also currently needed,
  * unless the relevant platforms (ARM/AT91, AVR32/AT32) are changed so
@@ -126,6 +125,8 @@ static struct clocksource clksrc = {
 struct tc_clkevt_device {
 	struct clock_event_device	clkevt;
 	struct clk			*clk;
+	bool				clk_enabled;
+	u32				freq;
 	void __iomem			*regs;
 };
 
@@ -134,15 +135,26 @@ static struct tc_clkevt_device *to_tc_cl
 	return container_of(clkevt, struct tc_clkevt_device, clkevt);
 }
 
-/* For now, we always use the 32K clock ... this optimizes for NO_HZ,
- * because using one of the divided clocks would usually mean the
- * tick rate can never be less than several dozen Hz (vs 0.5 Hz).
- *
- * A divided clock could be good for high resolution timers, since
- * 30.5 usec resolution can seem "low".
- */
 static u32 timer_clock;
 
+static void tc_clk_disable(struct clock_event_device *d)
+{
+	struct tc_clkevt_device *tcd = to_tc_clkevt(d);
+
+	clk_disable(tcd->clk);
+	tcd->clk_enabled = false;
+}
+
+static void tc_clk_enable(struct clock_event_device *d)
+{
+	struct tc_clkevt_device *tcd = to_tc_clkevt(d);
+
+	if (tcd->clk_enabled)
+		return;
+	clk_enable(tcd->clk);
+	tcd->clk_enabled = true;
+}
+
 static int tc_shutdown(struct clock_event_device *d)
 {
 	struct tc_clkevt_device *tcd = to_tc_clkevt(d);
@@ -150,8 +162,14 @@ static int tc_shutdown(struct clock_even
 
 	writel(0xff, regs + ATMEL_TC_REG(2, IDR));
 	writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
+	return 0;
+}
+
+static int tc_shutdown_clk_off(struct clock_event_device *d)
+{
+	tc_shutdown(d);
 	if (!clockevent_state_detached(d))
-		clk_disable(tcd->clk);
+		tc_clk_disable(d);
 
 	return 0;
 }
@@ -164,9 +182,9 @@ static int tc_set_oneshot(struct clock_e
 	if (clockevent_state_oneshot(d) || clockevent_state_periodic(d))
 		tc_shutdown(d);
 
-	clk_enable(tcd->clk);
+	tc_clk_enable(d);
 
-	/* slow clock, count up to RC, then irq and stop */
+	/* count up to RC, then irq and stop */
 	writel(timer_clock | ATMEL_TC_CPCSTOP | ATMEL_TC_WAVE |
 		     ATMEL_TC_WAVESEL_UP_AUTO, regs + ATMEL_TC_REG(2, CMR));
 	writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
@@ -186,12 +204,12 @@ static int tc_set_periodic(struct clock_
 	/* By not making the gentime core emulate periodic mode on top
 	 * of oneshot, we get lower overhead and improved accuracy.
 	 */
-	clk_enable(tcd->clk);
+	tc_clk_enable(d);
 
-	/* slow clock, count up to RC, then irq and restart */
+	/* count up to RC, then irq and restart */
 	writel(timer_clock | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
 		     regs + ATMEL_TC_REG(2, CMR));
-	writel((32768 + HZ / 2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
+	writel((tcd->freq + HZ / 2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
 
 	/* Enable clock and interrupts on RC compare */
 	writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
@@ -218,9 +236,13 @@ static struct tc_clkevt_device clkevt =
 		.features		= CLOCK_EVT_FEAT_PERIODIC |
 					  CLOCK_EVT_FEAT_ONESHOT,
 		/* Should be lower than at91rm9200's system timer */
+#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
 		.rating			= 125,
+#else
+		.rating			= 200,
+#endif
 		.set_next_event		= tc_next_event,
-		.set_state_shutdown	= tc_shutdown,
+		.set_state_shutdown	= tc_shutdown_clk_off,
 		.set_state_periodic	= tc_set_periodic,
 		.set_state_oneshot	= tc_set_oneshot,
 	},
@@ -240,8 +262,9 @@ static irqreturn_t ch2_irq(int irq, void
 	return IRQ_NONE;
 }
 
-static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int divisor_idx)
 {
+	unsigned divisor = atmel_tc_divisors[divisor_idx];
 	int ret;
 	struct clk *t2_clk = tc->clk[2];
 	int irq = tc->irq[2];
@@ -262,7 +285,11 @@ static int __init setup_clkevents(struct
 	clkevt.regs = tc->regs;
 	clkevt.clk = t2_clk;
 
-	timer_clock = clk32k_divisor_idx;
+	timer_clock = divisor_idx;
+	if (!divisor)
+		clkevt.freq = 32768;
+	else
+		clkevt.freq = clk_get_rate(t2_clk) / divisor;
 
 	clkevt.clkevt.cpumask = cpumask_of(0);
 
@@ -273,7 +300,7 @@ static int __init setup_clkevents(struct
 		return ret;
 	}
 
-	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+	clockevents_config_and_register(&clkevt.clkevt, clkevt.freq, 1, 0xffff);
 
 	return ret;
 }
@@ -410,7 +437,11 @@ static int __init tcb_clksrc_init(void)
 		goto err_disable_t1;
 
 	/* channel 2:  periodic and oneshot timer support */
+#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
 	ret = setup_clkevents(tc, clk32k_divisor_idx);
+#else
+	ret = setup_clkevents(tc, best_divisor_idx);
+#endif
 	if (ret)
 		goto err_unregister_clksrc;
 
Index: linux-4.19.25-rt16/drivers/clocksource/timer-atmel-tcb.c
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/drivers/clocksource/timer-atmel-tcb.c
@@ -0,0 +1,617 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/regmap.h>
+#include <linux/sched_clock.h>
+#include <soc/at91/atmel_tcb.h>
+
+struct atmel_tcb_clksrc {
+	struct clocksource clksrc;
+	struct clock_event_device clkevt;
+	struct regmap *regmap;
+	void __iomem *base;
+	struct clk *clk[2];
+	char name[20];
+	int channels[2];
+	int bits;
+	int irq;
+	struct {
+		u32 cmr;
+		u32 imr;
+		u32 rc;
+		bool clken;
+	} cache[2];
+	u32 bmr_cache;
+	bool registered;
+	bool clk_enabled;
+};
+
+static struct atmel_tcb_clksrc tc, tce;
+
+static struct clk *tcb_clk_get(struct device_node *node, int channel)
+{
+	struct clk *clk;
+	char clk_name[] = "t0_clk";
+
+	clk_name[1] += channel;
+	clk = of_clk_get_by_name(node->parent, clk_name);
+	if (!IS_ERR(clk))
+		return clk;
+
+	return of_clk_get_by_name(node->parent, "t0_clk");
+}
+
+/*
+ * Clockevent device using its own channel
+ */
+
+static void tc_clkevt2_clk_disable(struct clock_event_device *d)
+{
+	clk_disable(tce.clk[0]);
+	tce.clk_enabled = false;
+}
+
+static void tc_clkevt2_clk_enable(struct clock_event_device *d)
+{
+	if (tce.clk_enabled)
+		return;
+	clk_enable(tce.clk[0]);
+	tce.clk_enabled = true;
+}
+
+static int tc_clkevt2_stop(struct clock_event_device *d)
+{
+	writel(0xff, tce.base + ATMEL_TC_IDR(tce.channels[0]));
+	writel(ATMEL_TC_CCR_CLKDIS, tce.base + ATMEL_TC_CCR(tce.channels[0]));
+
+	return 0;
+}
+
+static int tc_clkevt2_shutdown(struct clock_event_device *d)
+{
+	tc_clkevt2_stop(d);
+	if (!clockevent_state_detached(d))
+		tc_clkevt2_clk_disable(d);
+
+	return 0;
+}
+
+/* For now, we always use the 32K clock ... this optimizes for NO_HZ,
+ * because using one of the divided clocks would usually mean the
+ * tick rate can never be less than several dozen Hz (vs 0.5 Hz).
+ *
+ * A divided clock could be good for high resolution timers, since
+ * 30.5 usec resolution can seem "low".
+ */
+static int tc_clkevt2_set_oneshot(struct clock_event_device *d)
+{
+	if (clockevent_state_oneshot(d) || clockevent_state_periodic(d))
+		tc_clkevt2_stop(d);
+
+	tc_clkevt2_clk_enable(d);
+
+	/* slow clock, count up to RC, then irq and stop */
+	writel(ATMEL_TC_CMR_TCLK(4) | ATMEL_TC_CMR_CPCSTOP |
+	       ATMEL_TC_CMR_WAVE | ATMEL_TC_CMR_WAVESEL_UPRC,
+	       tce.base + ATMEL_TC_CMR(tce.channels[0]));
+	writel(ATMEL_TC_CPCS, tce.base + ATMEL_TC_IER(tce.channels[0]));
+
+	return 0;
+}
+
+static int tc_clkevt2_set_periodic(struct clock_event_device *d)
+{
+	if (clockevent_state_oneshot(d) || clockevent_state_periodic(d))
+		tc_clkevt2_stop(d);
+
+	/* By not making the gentime core emulate periodic mode on top
+	 * of oneshot, we get lower overhead and improved accuracy.
+	 */
+	tc_clkevt2_clk_enable(d);
+
+	/* slow clock, count up to RC, then irq and restart */
+	writel(ATMEL_TC_CMR_TCLK(4) | ATMEL_TC_CMR_WAVE |
+	       ATMEL_TC_CMR_WAVESEL_UPRC,
+	       tce.base + ATMEL_TC_CMR(tce.channels[0]));
+	writel((32768 + HZ / 2) / HZ, tce.base + ATMEL_TC_RC(tce.channels[0]));
+
+	/* Enable clock and interrupts on RC compare */
+	writel(ATMEL_TC_CPCS, tce.base + ATMEL_TC_IER(tce.channels[0]));
+	writel(ATMEL_TC_CCR_CLKEN | ATMEL_TC_CCR_SWTRG,
+	       tce.base + ATMEL_TC_CCR(tce.channels[0]));
+
+	return 0;
+}
+
+static int tc_clkevt2_next_event(unsigned long delta,
+				 struct clock_event_device *d)
+{
+	writel(delta, tce.base + ATMEL_TC_RC(tce.channels[0]));
+	writel(ATMEL_TC_CCR_CLKEN | ATMEL_TC_CCR_SWTRG,
+	       tce.base + ATMEL_TC_CCR(tce.channels[0]));
+
+	return 0;
+}
+
+static irqreturn_t tc_clkevt2_irq(int irq, void *handle)
+{
+	unsigned int sr;
+
+	sr = readl(tce.base + ATMEL_TC_SR(tce.channels[0]));
+	if (sr & ATMEL_TC_CPCS) {
+		tce.clkevt.event_handler(&tce.clkevt);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static void tc_clkevt2_suspend(struct clock_event_device *d)
+{
+	tce.cache[0].cmr = readl(tce.base + ATMEL_TC_CMR(tce.channels[0]));
+	tce.cache[0].imr = readl(tce.base + ATMEL_TC_IMR(tce.channels[0]));
+	tce.cache[0].rc = readl(tce.base + ATMEL_TC_RC(tce.channels[0]));
+	tce.cache[0].clken = !!(readl(tce.base + ATMEL_TC_SR(tce.channels[0])) &
+				ATMEL_TC_CLKSTA);
+}
+
+static void tc_clkevt2_resume(struct clock_event_device *d)
+{
+	/* Restore registers for the channel, RA and RB are not used  */
+	writel(tce.cache[0].cmr, tc.base + ATMEL_TC_CMR(tce.channels[0]));
+	writel(tce.cache[0].rc, tc.base + ATMEL_TC_RC(tce.channels[0]));
+	writel(0, tc.base + ATMEL_TC_RA(tce.channels[0]));
+	writel(0, tc.base + ATMEL_TC_RB(tce.channels[0]));
+	/* Disable all the interrupts */
+	writel(0xff, tc.base + ATMEL_TC_IDR(tce.channels[0]));
+	/* Reenable interrupts that were enabled before suspending */
+	writel(tce.cache[0].imr, tc.base + ATMEL_TC_IER(tce.channels[0]));
+
+	/* Start the clock if it was used */
+	if (tce.cache[0].clken)
+		writel(ATMEL_TC_CCR_CLKEN | ATMEL_TC_CCR_SWTRG,
+		       tc.base + ATMEL_TC_CCR(tce.channels[0]));
+}
+
+static int __init tc_clkevt_register(struct device_node *node,
+				     struct regmap *regmap, void __iomem *base,
+				     int channel, int irq, int bits)
+{
+	int ret;
+	struct clk *slow_clk;
+
+	tce.regmap = regmap;
+	tce.base = base;
+	tce.channels[0] = channel;
+	tce.irq = irq;
+
+	slow_clk = of_clk_get_by_name(node->parent, "slow_clk");
+	if (IS_ERR(slow_clk))
+		return PTR_ERR(slow_clk);
+
+	ret = clk_prepare_enable(slow_clk);
+	if (ret)
+		return ret;
+
+	tce.clk[0] = tcb_clk_get(node, tce.channels[0]);
+	if (IS_ERR(tce.clk[0])) {
+		ret = PTR_ERR(tce.clk[0]);
+		goto err_slow;
+	}
+
+	snprintf(tce.name, sizeof(tce.name), "%s:%d",
+		 kbasename(node->parent->full_name), channel);
+	tce.clkevt.cpumask = cpumask_of(0);
+	tce.clkevt.name = tce.name;
+	tce.clkevt.set_next_event = tc_clkevt2_next_event,
+	tce.clkevt.set_state_shutdown = tc_clkevt2_shutdown,
+	tce.clkevt.set_state_periodic = tc_clkevt2_set_periodic,
+	tce.clkevt.set_state_oneshot = tc_clkevt2_set_oneshot,
+	tce.clkevt.suspend = tc_clkevt2_suspend,
+	tce.clkevt.resume = tc_clkevt2_resume,
+	tce.clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+	tce.clkevt.rating = 140;
+
+	/* try to enable clk to avoid future errors in mode change */
+	ret = clk_prepare_enable(tce.clk[0]);
+	if (ret)
+		goto err_slow;
+	clk_disable(tce.clk[0]);
+
+	clockevents_config_and_register(&tce.clkevt, 32768, 1,
+					CLOCKSOURCE_MASK(bits));
+
+	ret = request_irq(tce.irq, tc_clkevt2_irq, IRQF_TIMER | IRQF_SHARED,
+			  tce.clkevt.name, &tce);
+	if (ret)
+		goto err_clk;
+
+	tce.registered = true;
+
+	return 0;
+
+err_clk:
+	clk_unprepare(tce.clk[0]);
+err_slow:
+	clk_disable_unprepare(slow_clk);
+
+	return ret;
+}
+
+/*
+ * Clocksource and clockevent using the same channel(s)
+ */
+static u64 tc_get_cycles(struct clocksource *cs)
+{
+	u32 lower, upper;
+
+	do {
+		upper = readl_relaxed(tc.base + ATMEL_TC_CV(tc.channels[1]));
+		lower = readl_relaxed(tc.base + ATMEL_TC_CV(tc.channels[0]));
+	} while (upper != readl_relaxed(tc.base + ATMEL_TC_CV(tc.channels[1])));
+
+	return (upper << 16) | lower;
+}
+
+static u64 tc_get_cycles32(struct clocksource *cs)
+{
+	return readl_relaxed(tc.base + ATMEL_TC_CV(tc.channels[0]));
+}
+
+static u64 notrace tc_sched_clock_read(void)
+{
+	return tc_get_cycles(&tc.clksrc);
+}
+
+static u64 notrace tc_sched_clock_read32(void)
+{
+	return tc_get_cycles32(&tc.clksrc);
+}
+
+static int tcb_clkevt_next_event(unsigned long delta,
+				 struct clock_event_device *d)
+{
+	u32 old, next, cur;
+
+	old = readl(tc.base + ATMEL_TC_CV(tc.channels[0]));
+	next = old + delta;
+	writel(next, tc.base + ATMEL_TC_RC(tc.channels[0]));
+	cur = readl(tc.base + ATMEL_TC_CV(tc.channels[0]));
+
+	/* check whether the delta elapsed while setting the register */
+	if ((next < old && cur < old && cur > next) ||
+	    (next > old && (cur < old || cur > next))) {
+		/*
+		 * Clear the CPCS bit in the status register to avoid
+		 * generating a spurious interrupt next time a valid
+		 * timer event is configured.
+		 */
+		old = readl(tc.base + ATMEL_TC_SR(tc.channels[0]));
+		return -ETIME;
+	}
+
+	writel(ATMEL_TC_CPCS, tc.base + ATMEL_TC_IER(tc.channels[0]));
+
+	return 0;
+}
+
+static irqreturn_t tc_clkevt_irq(int irq, void *handle)
+{
+	unsigned int sr;
+
+	sr = readl(tc.base + ATMEL_TC_SR(tc.channels[0]));
+	if (sr & ATMEL_TC_CPCS) {
+		tc.clkevt.event_handler(&tc.clkevt);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int tcb_clkevt_oneshot(struct clock_event_device *dev)
+{
+	if (clockevent_state_oneshot(dev))
+		return 0;
+
+	/*
+	 * Because both clockevent devices may share the same IRQ, we don't want
+	 * the less likely one to stay requested
+	 */
+	return request_irq(tc.irq, tc_clkevt_irq, IRQF_TIMER | IRQF_SHARED,
+			   tc.name, &tc);
+}
+
+static int tcb_clkevt_shutdown(struct clock_event_device *dev)
+{
+	writel(0xff, tc.base + ATMEL_TC_IDR(tc.channels[0]));
+	if (tc.bits == 16)
+		writel(0xff, tc.base + ATMEL_TC_IDR(tc.channels[1]));
+
+	if (!clockevent_state_detached(dev))
+		free_irq(tc.irq, &tc);
+
+	return 0;
+}
+
+static void __init tcb_setup_dual_chan(struct atmel_tcb_clksrc *tc,
+				       int mck_divisor_idx)
+{
+	/* first channel: waveform mode, input mclk/8, clock TIOA on overflow */
+	writel(mck_divisor_idx			/* likely divide-by-8 */
+	       | ATMEL_TC_CMR_WAVE
+	       | ATMEL_TC_CMR_WAVESEL_UP	/* free-run */
+	       | ATMEL_TC_CMR_ACPA(SET)		/* TIOA rises at 0 */
+	       | ATMEL_TC_CMR_ACPC(CLEAR),	/* (duty cycle 50%) */
+	       tc->base + ATMEL_TC_CMR(tc->channels[0]));
+	writel(0x0000, tc->base + ATMEL_TC_RA(tc->channels[0]));
+	writel(0x8000, tc->base + ATMEL_TC_RC(tc->channels[0]));
+	writel(0xff, tc->base + ATMEL_TC_IDR(tc->channels[0]));	/* no irqs */
+	writel(ATMEL_TC_CCR_CLKEN, tc->base + ATMEL_TC_CCR(tc->channels[0]));
+
+	/* second channel: waveform mode, input TIOA */
+	writel(ATMEL_TC_CMR_XC(tc->channels[1])		/* input: TIOA */
+	       | ATMEL_TC_CMR_WAVE
+	       | ATMEL_TC_CMR_WAVESEL_UP,		/* free-run */
+	       tc->base + ATMEL_TC_CMR(tc->channels[1]));
+	writel(0xff, tc->base + ATMEL_TC_IDR(tc->channels[1]));	/* no irqs */
+	writel(ATMEL_TC_CCR_CLKEN, tc->base + ATMEL_TC_CCR(tc->channels[1]));
+
+	/* chain both channel, we assume the previous channel */
+	regmap_write(tc->regmap, ATMEL_TC_BMR,
+		     ATMEL_TC_BMR_TCXC(1 + tc->channels[1], tc->channels[1]));
+	/* then reset all the timers */
+	regmap_write(tc->regmap, ATMEL_TC_BCR, ATMEL_TC_BCR_SYNC);
+}
+
+static void __init tcb_setup_single_chan(struct atmel_tcb_clksrc *tc,
+					 int mck_divisor_idx)
+{
+	/* channel 0:  waveform mode, input mclk/8 */
+	writel(mck_divisor_idx			/* likely divide-by-8 */
+	       | ATMEL_TC_CMR_WAVE
+	       | ATMEL_TC_CMR_WAVESEL_UP,	/* free-run */
+	       tc->base + ATMEL_TC_CMR(tc->channels[0]));
+	writel(0xff, tc->base + ATMEL_TC_IDR(tc->channels[0]));	/* no irqs */
+	writel(ATMEL_TC_CCR_CLKEN, tc->base + ATMEL_TC_CCR(tc->channels[0]));
+
+	/* then reset all the timers */
+	regmap_write(tc->regmap, ATMEL_TC_BCR, ATMEL_TC_BCR_SYNC);
+}
+
+static void tc_clksrc_suspend(struct clocksource *cs)
+{
+	int i;
+
+	for (i = 0; i < 1 + (tc.bits == 16); i++) {
+		tc.cache[i].cmr = readl(tc.base + ATMEL_TC_CMR(tc.channels[i]));
+		tc.cache[i].imr = readl(tc.base + ATMEL_TC_IMR(tc.channels[i]));
+		tc.cache[i].rc = readl(tc.base + ATMEL_TC_RC(tc.channels[i]));
+		tc.cache[i].clken = !!(readl(tc.base +
+					     ATMEL_TC_SR(tc.channels[i])) &
+				       ATMEL_TC_CLKSTA);
+	}
+
+	if (tc.bits == 16)
+		regmap_read(tc.regmap, ATMEL_TC_BMR, &tc.bmr_cache);
+}
+
+static void tc_clksrc_resume(struct clocksource *cs)
+{
+	int i;
+
+	for (i = 0; i < 1 + (tc.bits == 16); i++) {
+		/* Restore registers for the channel, RA and RB are not used  */
+		writel(tc.cache[i].cmr, tc.base + ATMEL_TC_CMR(tc.channels[i]));
+		writel(tc.cache[i].rc, tc.base + ATMEL_TC_RC(tc.channels[i]));
+		writel(0, tc.base + ATMEL_TC_RA(tc.channels[i]));
+		writel(0, tc.base + ATMEL_TC_RB(tc.channels[i]));
+		/* Disable all the interrupts */
+		writel(0xff, tc.base + ATMEL_TC_IDR(tc.channels[i]));
+		/* Reenable interrupts that were enabled before suspending */
+		writel(tc.cache[i].imr, tc.base + ATMEL_TC_IER(tc.channels[i]));
+
+		/* Start the clock if it was used */
+		if (tc.cache[i].clken)
+			writel(ATMEL_TC_CCR_CLKEN, tc.base +
+			       ATMEL_TC_CCR(tc.channels[i]));
+	}
+
+	/* in case of dual channel, chain channels */
+	if (tc.bits == 16)
+		regmap_write(tc.regmap, ATMEL_TC_BMR, tc.bmr_cache);
+	/* Finally, trigger all the channels*/
+	regmap_write(tc.regmap, ATMEL_TC_BCR, ATMEL_TC_BCR_SYNC);
+}
+
+static int __init tcb_clksrc_register(struct device_node *node,
+				      struct regmap *regmap, void __iomem *base,
+				      int channel, int channel1, int irq,
+				      int bits)
+{
+	u32 rate, divided_rate = 0;
+	int best_divisor_idx = -1;
+	int i, err = -1;
+	u64 (*tc_sched_clock)(void);
+
+	tc.regmap = regmap;
+	tc.base = base;
+	tc.channels[0] = channel;
+	tc.channels[1] = channel1;
+	tc.irq = irq;
+	tc.bits = bits;
+
+	tc.clk[0] = tcb_clk_get(node, tc.channels[0]);
+	if (IS_ERR(tc.clk[0]))
+		return PTR_ERR(tc.clk[0]);
+	err = clk_prepare_enable(tc.clk[0]);
+	if (err) {
+		pr_debug("can't enable T0 clk\n");
+		goto err_clk;
+	}
+
+	/* How fast will we be counting?  Pick something over 5 MHz.  */
+	rate = (u32)clk_get_rate(tc.clk[0]);
+	for (i = 0; i < 5; i++) {
+		unsigned int divisor = atmel_tc_divisors[i];
+		unsigned int tmp;
+
+		if (!divisor)
+			continue;
+
+		tmp = rate / divisor;
+		pr_debug("TC: %u / %-3u [%d] --> %u\n", rate, divisor, i, tmp);
+		if (best_divisor_idx > 0) {
+			if (tmp < 5 * 1000 * 1000)
+				continue;
+		}
+		divided_rate = tmp;
+		best_divisor_idx = i;
+	}
+
+	if (tc.bits == 32) {
+		tc.clksrc.read = tc_get_cycles32;
+		tcb_setup_single_chan(&tc, best_divisor_idx);
+		tc_sched_clock = tc_sched_clock_read32;
+		snprintf(tc.name, sizeof(tc.name), "%s:%d",
+			 kbasename(node->parent->full_name), tc.channels[0]);
+	} else {
+		tc.clk[1] = tcb_clk_get(node, tc.channels[1]);
+		if (IS_ERR(tc.clk[1]))
+			goto err_disable_t0;
+
+		err = clk_prepare_enable(tc.clk[1]);
+		if (err) {
+			pr_debug("can't enable T1 clk\n");
+			goto err_clk1;
+		}
+		tc.clksrc.read = tc_get_cycles,
+		tcb_setup_dual_chan(&tc, best_divisor_idx);
+		tc_sched_clock = tc_sched_clock_read;
+		snprintf(tc.name, sizeof(tc.name), "%s:%d,%d",
+			 kbasename(node->parent->full_name), tc.channels[0],
+			 tc.channels[1]);
+	}
+
+	pr_debug("%s at %d.%03d MHz\n", tc.name,
+		 divided_rate / 1000000,
+		 ((divided_rate + 500000) % 1000000) / 1000);
+
+	tc.clksrc.name = tc.name;
+	tc.clksrc.suspend = tc_clksrc_suspend;
+	tc.clksrc.resume = tc_clksrc_resume;
+	tc.clksrc.rating = 200;
+	tc.clksrc.mask = CLOCKSOURCE_MASK(32);
+	tc.clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+	err = clocksource_register_hz(&tc.clksrc, divided_rate);
+	if (err)
+		goto err_disable_t1;
+
+	sched_clock_register(tc_sched_clock, 32, divided_rate);
+
+	tc.registered = true;
+
+	/* Set up and register clockevents */
+	tc.clkevt.name = tc.name;
+	tc.clkevt.cpumask = cpumask_of(0);
+	tc.clkevt.set_next_event = tcb_clkevt_next_event;
+	tc.clkevt.set_state_oneshot = tcb_clkevt_oneshot;
+	tc.clkevt.set_state_shutdown = tcb_clkevt_shutdown;
+	tc.clkevt.features = CLOCK_EVT_FEAT_ONESHOT;
+	tc.clkevt.rating = 125;
+
+	clockevents_config_and_register(&tc.clkevt, divided_rate, 1,
+					BIT(tc.bits) - 1);
+
+	return 0;
+
+err_disable_t1:
+	if (tc.bits == 16)
+		clk_disable_unprepare(tc.clk[1]);
+
+err_clk1:
+	if (tc.bits == 16)
+		clk_put(tc.clk[1]);
+
+err_disable_t0:
+	clk_disable_unprepare(tc.clk[0]);
+
+err_clk:
+	clk_put(tc.clk[0]);
+
+	pr_err("%s: unable to register clocksource/clockevent\n",
+	       tc.clksrc.name);
+
+	return err;
+}
+
+static int __init tcb_clksrc_init(struct device_node *node)
+{
+	const struct of_device_id *match;
+	struct regmap *regmap;
+	void __iomem *tcb_base;
+	u32 channel;
+	int irq, err, chan1 = -1;
+	unsigned bits;
+
+	if (tc.registered && tce.registered)
+		return -ENODEV;
+
+	/*
+	 * The regmap has to be used to access registers that are shared
+	 * between channels on the same TCB but we keep direct IO access for
+	 * the counters to avoid the impact on performance
+	 */
+	regmap = syscon_node_to_regmap(node->parent);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	tcb_base = of_iomap(node->parent, 0);
+	if (!tcb_base) {
+		pr_err("%s +%d %s\n", __FILE__, __LINE__, __func__);
+		return -ENXIO;
+	}
+
+	match = of_match_node(atmel_tcb_dt_ids, node->parent);
+	bits = (uintptr_t)match->data;
+
+	err = of_property_read_u32_index(node, "reg", 0, &channel);
+	if (err)
+		return err;
+
+	irq = of_irq_get(node->parent, channel);
+	if (irq < 0) {
+		irq = of_irq_get(node->parent, 0);
+		if (irq < 0)
+			return irq;
+	}
+
+	if (tc.registered)
+		return tc_clkevt_register(node, regmap, tcb_base, channel, irq,
+					  bits);
+
+	if (bits == 16) {
+		of_property_read_u32_index(node, "reg", 1, &chan1);
+		if (chan1 == -1) {
+			if (tce.registered) {
+				pr_err("%s: clocksource needs two channels\n",
+				       node->parent->full_name);
+				return -EINVAL;
+			} else {
+				return tc_clkevt_register(node, regmap,
+							  tcb_base, channel,
+							  irq, bits);
+			}
+		}
+	}
+
+	return tcb_clksrc_register(node, regmap, tcb_base, channel, chan1, irq,
+				   bits);
+}
+TIMER_OF_DECLARE(atmel_tcb_clksrc, "atmel,tcb-timer", tcb_clksrc_init);
Index: linux-4.19.25-rt16/drivers/connector/cn_proc.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/connector/cn_proc.c
+++ linux-4.19.25-rt16/drivers/connector/cn_proc.c
@@ -32,6 +32,7 @@
 #include <linux/pid_namespace.h>
 
 #include <linux/cn_proc.h>
+#include <linux/locallock.h>
 
 /*
  * Size of a cn_msg followed by a proc_event structure.  Since the
@@ -54,10 +55,11 @@ static struct cb_id cn_proc_event_id = {
 
 /* proc_event_counts is used as the sequence number of the netlink message */
 static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
+static DEFINE_LOCAL_IRQ_LOCK(send_msg_lock);
 
 static inline void send_msg(struct cn_msg *msg)
 {
-	preempt_disable();
+	local_lock(send_msg_lock);
 
 	msg->seq = __this_cpu_inc_return(proc_event_counts) - 1;
 	((struct proc_event *)msg->data)->cpu = smp_processor_id();
@@ -70,7 +72,7 @@ static inline void send_msg(struct cn_ms
 	 */
 	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);
 
-	preempt_enable();
+	local_unlock(send_msg_lock);
 }
 
 void proc_fork_connector(struct task_struct *task)
Index: linux-4.19.25-rt16/drivers/cpufreq/Kconfig.x86
===================================================================
--- linux-4.19.25-rt16.orig/drivers/cpufreq/Kconfig.x86
+++ linux-4.19.25-rt16/drivers/cpufreq/Kconfig.x86
@@ -125,7 +125,7 @@ config X86_POWERNOW_K7_ACPI
 
 config X86_POWERNOW_K8
 	tristate "AMD Opteron/Athlon64 PowerNow!"
-	depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ
+	depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ && !PREEMPT_RT_BASE
 	help
 	  This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors.
 	  Support for K10 and newer processors is now in acpi-cpufreq.
Index: linux-4.19.25-rt16/drivers/crypto/caam/qi.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/crypto/caam/qi.c
+++ linux-4.19.25-rt16/drivers/crypto/caam/qi.c
@@ -84,13 +84,6 @@ static u64 times_congested;
 #endif
 
 /*
- * CPU from where the module initialised. This is required because QMan driver
- * requires CGRs to be removed from same CPU from where they were originally
- * allocated.
- */
-static int mod_init_cpu;
-
-/*
  * This is a a cache of buffers, from which the users of CAAM QI driver
  * can allocate short (CAAM_QI_MEMCACHE_SIZE) buffers. It's faster than
  * doing malloc on the hotpath.
@@ -492,12 +485,11 @@ void caam_drv_ctx_rel(struct caam_drv_ct
 }
 EXPORT_SYMBOL(caam_drv_ctx_rel);
 
-int caam_qi_shutdown(struct device *qidev)
+void caam_qi_shutdown(struct device *qidev)
 {
-	int i, ret;
+	int i;
 	struct caam_qi_priv *priv = dev_get_drvdata(qidev);
 	const cpumask_t *cpus = qman_affine_cpus();
-	struct cpumask old_cpumask = current->cpus_allowed;
 
 	for_each_cpu(i, cpus) {
 		struct napi_struct *irqtask;
@@ -510,26 +502,12 @@ int caam_qi_shutdown(struct device *qide
 			dev_err(qidev, "Rsp FQ kill failed, cpu: %d\n", i);
 	}
 
-	/*
-	 * QMan driver requires CGRs to be deleted from same CPU from where they
-	 * were instantiated. Hence we get the module removal execute from the
-	 * same CPU from where it was originally inserted.
-	 */
-	set_cpus_allowed_ptr(current, get_cpu_mask(mod_init_cpu));
-
-	ret = qman_delete_cgr(&priv->cgr);
-	if (ret)
-		dev_err(qidev, "Deletion of CGR failed: %d\n", ret);
-	else
-		qman_release_cgrid(priv->cgr.cgrid);
+	qman_delete_cgr_safe(&priv->cgr);
+	qman_release_cgrid(priv->cgr.cgrid);
 
 	kmem_cache_destroy(qi_cache);
 
-	/* Now that we're done with the CGRs, restore the cpus allowed mask */
-	set_cpus_allowed_ptr(current, &old_cpumask);
-
 	platform_device_unregister(priv->qi_pdev);
-	return ret;
 }
 
 static void cgr_cb(struct qman_portal *qm, struct qman_cgr *cgr, int congested)
@@ -718,22 +696,11 @@ int caam_qi_init(struct platform_device
 	struct device *ctrldev = &caam_pdev->dev, *qidev;
 	struct caam_drv_private *ctrlpriv;
 	const cpumask_t *cpus = qman_affine_cpus();
-	struct cpumask old_cpumask = current->cpus_allowed;
 	static struct platform_device_info qi_pdev_info = {
 		.name = "caam_qi",
 		.id = PLATFORM_DEVID_NONE
 	};
 
-	/*
-	 * QMAN requires CGRs to be removed from same CPU+portal from where it
-	 * was originally allocated. Hence we need to note down the
-	 * initialisation CPU and use the same CPU for module exit.
-	 * We select the first CPU to from the list of portal owning CPUs.
-	 * Then we pin module init to this CPU.
-	 */
-	mod_init_cpu = cpumask_first(cpus);
-	set_cpus_allowed_ptr(current, get_cpu_mask(mod_init_cpu));
-
 	qi_pdev_info.parent = ctrldev;
 	qi_pdev_info.dma_mask = dma_get_mask(ctrldev);
 	qi_pdev = platform_device_register_full(&qi_pdev_info);
@@ -795,8 +762,6 @@ int caam_qi_init(struct platform_device
 		return -ENOMEM;
 	}
 
-	/* Done with the CGRs; restore the cpus allowed mask */
-	set_cpus_allowed_ptr(current, &old_cpumask);
 #ifdef CONFIG_DEBUG_FS
 	debugfs_create_file("qi_congested", 0444, ctrlpriv->ctl,
 			    &times_congested, &caam_fops_u64_ro);
Index: linux-4.19.25-rt16/drivers/crypto/caam/qi.h
===================================================================
--- linux-4.19.25-rt16.orig/drivers/crypto/caam/qi.h
+++ linux-4.19.25-rt16/drivers/crypto/caam/qi.h
@@ -174,7 +174,7 @@ int caam_drv_ctx_update(struct caam_drv_
 void caam_drv_ctx_rel(struct caam_drv_ctx *drv_ctx);
 
 int caam_qi_init(struct platform_device *pdev);
-int caam_qi_shutdown(struct device *dev);
+void caam_qi_shutdown(struct device *dev);
 
 /**
  * qi_cache_alloc - Allocate buffers from CAAM-QI cache
Index: linux-4.19.25-rt16/drivers/firmware/efi/efi.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/firmware/efi/efi.c
+++ linux-4.19.25-rt16/drivers/firmware/efi/efi.c
@@ -87,7 +87,7 @@ struct mm_struct efi_mm = {
 
 struct workqueue_struct *efi_rts_wq;
 
-static bool disable_runtime;
+static bool disable_runtime = IS_ENABLED(CONFIG_PREEMPT_RT_BASE);
 static int __init setup_noefi(char *arg)
 {
 	disable_runtime = true;
@@ -113,6 +113,9 @@ static int __init parse_efi_cmdline(char
 	if (parse_option_str(str, "noruntime"))
 		disable_runtime = true;
 
+	if (parse_option_str(str, "runtime"))
+		disable_runtime = false;
+
 	return 0;
 }
 early_param("efi", parse_efi_cmdline);
Index: linux-4.19.25-rt16/drivers/gpu/drm/i915/i915_irq.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/gpu/drm/i915/i915_irq.c
+++ linux-4.19.25-rt16/drivers/gpu/drm/i915/i915_irq.c
@@ -1025,6 +1025,7 @@ static bool i915_get_crtc_scanoutpos(str
 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
 	/* preempt_disable_rt() should go right here in PREEMPT_RT patchset. */
+	preempt_disable_rt();
 
 	/* Get optional system timestamp before query. */
 	if (stime)
@@ -1076,6 +1077,7 @@ static bool i915_get_crtc_scanoutpos(str
 		*etime = ktime_get();
 
 	/* preempt_enable_rt() should go right here in PREEMPT_RT patchset. */
+	preempt_enable_rt();
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 
Index: linux-4.19.25-rt16/drivers/gpu/drm/i915/i915_request.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/gpu/drm/i915/i915_request.c
+++ linux-4.19.25-rt16/drivers/gpu/drm/i915/i915_request.c
@@ -356,9 +356,7 @@ static void __retire_engine_request(stru
 
 	GEM_BUG_ON(!i915_request_completed(rq));
 
-	local_irq_disable();
-
-	spin_lock(&engine->timeline.lock);
+	spin_lock_irq(&engine->timeline.lock);
 	GEM_BUG_ON(!list_is_first(&rq->link, &engine->timeline.requests));
 	list_del_init(&rq->link);
 	spin_unlock(&engine->timeline.lock);
@@ -372,9 +370,7 @@ static void __retire_engine_request(stru
 		GEM_BUG_ON(!atomic_read(&rq->i915->gt_pm.rps.num_waiters));
 		atomic_dec(&rq->i915->gt_pm.rps.num_waiters);
 	}
-	spin_unlock(&rq->lock);
-
-	local_irq_enable();
+	spin_unlock_irq(&rq->lock);
 
 	/*
 	 * The backing object for the context is done after switching to the
Index: linux-4.19.25-rt16/drivers/gpu/drm/i915/i915_trace.h
===================================================================
--- linux-4.19.25-rt16.orig/drivers/gpu/drm/i915/i915_trace.h
+++ linux-4.19.25-rt16/drivers/gpu/drm/i915/i915_trace.h
@@ -2,6 +2,10 @@
 #if !defined(_I915_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ)
 #define _I915_TRACE_H_
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+#define NOTRACE
+#endif
+
 #include <linux/stringify.h>
 #include <linux/types.h>
 #include <linux/tracepoint.h>
@@ -679,7 +683,7 @@ DEFINE_EVENT(i915_request, i915_request_
 	    TP_ARGS(rq)
 );
 
-#if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS)
+#if defined(CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS) && !defined(NOTRACE)
 DEFINE_EVENT(i915_request, i915_request_submit,
 	     TP_PROTO(struct i915_request *rq),
 	     TP_ARGS(rq)
Index: linux-4.19.25-rt16/drivers/gpu/drm/i915/intel_sprite.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/gpu/drm/i915/intel_sprite.c
+++ linux-4.19.25-rt16/drivers/gpu/drm/i915/intel_sprite.c
@@ -36,6 +36,7 @@
 #include <drm/drm_rect.h>
 #include <drm/drm_atomic.h>
 #include <drm/drm_plane_helper.h>
+#include <linux/locallock.h>
 #include "intel_drv.h"
 #include "intel_frontbuffer.h"
 #include <drm/i915_drm.h>
@@ -60,6 +61,8 @@ int intel_usecs_to_scanlines(const struc
 #define VBLANK_EVASION_TIME_US 100
 #endif
 
+static DEFINE_LOCAL_IRQ_LOCK(pipe_update_lock);
+
 /**
  * intel_pipe_update_start() - start update of a set of display registers
  * @new_crtc_state: the new crtc state
@@ -107,7 +110,7 @@ void intel_pipe_update_start(const struc
 	if (intel_psr_wait_for_idle(new_crtc_state))
 		DRM_ERROR("PSR idle timed out, atomic update may fail\n");
 
-	local_irq_disable();
+	local_lock_irq(pipe_update_lock);
 
 	crtc->debug.min_vbl = min;
 	crtc->debug.max_vbl = max;
@@ -131,11 +134,11 @@ void intel_pipe_update_start(const struc
 			break;
 		}
 
-		local_irq_enable();
+		local_unlock_irq(pipe_update_lock);
 
 		timeout = schedule_timeout(timeout);
 
-		local_irq_disable();
+		local_lock_irq(pipe_update_lock);
 	}
 
 	finish_wait(wq, &wait);
@@ -168,7 +171,7 @@ void intel_pipe_update_start(const struc
 	return;
 
 irq_disable:
-	local_irq_disable();
+	local_lock_irq(pipe_update_lock);
 }
 
 /**
@@ -204,7 +207,7 @@ void intel_pipe_update_end(struct intel_
 		new_crtc_state->base.event = NULL;
 	}
 
-	local_irq_enable();
+	local_unlock_irq(pipe_update_lock);
 
 	if (intel_vgpu_active(dev_priv))
 		return;
Index: linux-4.19.25-rt16/drivers/gpu/drm/radeon/radeon_display.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/gpu/drm/radeon/radeon_display.c
+++ linux-4.19.25-rt16/drivers/gpu/drm/radeon/radeon_display.c
@@ -1813,6 +1813,7 @@ int radeon_get_crtc_scanoutpos(struct dr
 	struct radeon_device *rdev = dev->dev_private;
 
 	/* preempt_disable_rt() should go right here in PREEMPT_RT patchset. */
+	preempt_disable_rt();
 
 	/* Get optional system timestamp before query. */
 	if (stime)
@@ -1905,6 +1906,7 @@ int radeon_get_crtc_scanoutpos(struct dr
 		*etime = ktime_get();
 
 	/* preempt_enable_rt() should go right here in PREEMPT_RT patchset. */
+	preempt_enable_rt();
 
 	/* Decode into vertical and horizontal scanout position. */
 	*vpos = position & 0x1fff;
Index: linux-4.19.25-rt16/drivers/hv/hv.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/hv/hv.c
+++ linux-4.19.25-rt16/drivers/hv/hv.c
@@ -112,10 +112,12 @@ int hv_post_message(union hv_connection_
 static void hv_stimer0_isr(void)
 {
 	struct hv_per_cpu_context *hv_cpu;
+	struct pt_regs *regs = get_irq_regs();
+	u64 ip = regs ? instruction_pointer(regs) : 0;
 
 	hv_cpu = this_cpu_ptr(hv_context.cpu_context);
 	hv_cpu->clk_evt->event_handler(hv_cpu->clk_evt);
-	add_interrupt_randomness(stimer0_vector, 0);
+	add_interrupt_randomness(stimer0_vector, 0, ip);
 }
 
 static int hv_ce_set_next_event(unsigned long delta,
Index: linux-4.19.25-rt16/drivers/hv/hyperv_vmbus.h
===================================================================
--- linux-4.19.25-rt16.orig/drivers/hv/hyperv_vmbus.h
+++ linux-4.19.25-rt16/drivers/hv/hyperv_vmbus.h
@@ -31,6 +31,7 @@
 #include <linux/atomic.h>
 #include <linux/hyperv.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 
 #include "hv_trace.h"
 
Index: linux-4.19.25-rt16/drivers/hv/vmbus_drv.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/hv/vmbus_drv.c
+++ linux-4.19.25-rt16/drivers/hv/vmbus_drv.c
@@ -1042,6 +1042,8 @@ static void vmbus_isr(void)
 	void *page_addr = hv_cpu->synic_event_page;
 	struct hv_message *msg;
 	union hv_synic_event_flags *event;
+	struct pt_regs *regs = get_irq_regs();
+	u64 ip = regs ? instruction_pointer(regs) : 0;
 	bool handled = false;
 
 	if (unlikely(page_addr == NULL))
@@ -1085,7 +1087,7 @@ static void vmbus_isr(void)
 			tasklet_schedule(&hv_cpu->msg_dpc);
 	}
 
-	add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
+	add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0, ip);
 }
 
 /*
Index: linux-4.19.25-rt16/drivers/infiniband/hw/hfi1/affinity.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/infiniband/hw/hfi1/affinity.c
+++ linux-4.19.25-rt16/drivers/infiniband/hw/hfi1/affinity.c
@@ -1037,7 +1037,7 @@ int hfi1_get_proc_affinity(int node)
 	struct hfi1_affinity_node *entry;
 	cpumask_var_t diff, hw_thread_mask, available_mask, intrs_mask;
 	const struct cpumask *node_mask,
-		*proc_mask = &current->cpus_allowed;
+		*proc_mask = current->cpus_ptr;
 	struct hfi1_affinity_node_list *affinity = &node_affinity;
 	struct cpu_mask_set *set = &affinity->proc;
 
@@ -1045,7 +1045,7 @@ int hfi1_get_proc_affinity(int node)
 	 * check whether process/context affinity has already
 	 * been set
 	 */
-	if (cpumask_weight(proc_mask) == 1) {
+	if (current->nr_cpus_allowed == 1) {
 		hfi1_cdbg(PROC, "PID %u %s affinity set to CPU %*pbl",
 			  current->pid, current->comm,
 			  cpumask_pr_args(proc_mask));
@@ -1056,7 +1056,7 @@ int hfi1_get_proc_affinity(int node)
 		cpu = cpumask_first(proc_mask);
 		cpumask_set_cpu(cpu, &set->used);
 		goto done;
-	} else if (cpumask_weight(proc_mask) < cpumask_weight(&set->mask)) {
+	} else if (current->nr_cpus_allowed < cpumask_weight(&set->mask)) {
 		hfi1_cdbg(PROC, "PID %u %s affinity set to CPU set(s) %*pbl",
 			  current->pid, current->comm,
 			  cpumask_pr_args(proc_mask));
Index: linux-4.19.25-rt16/drivers/infiniband/hw/hfi1/sdma.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/infiniband/hw/hfi1/sdma.c
+++ linux-4.19.25-rt16/drivers/infiniband/hw/hfi1/sdma.c
@@ -855,14 +855,13 @@ struct sdma_engine *sdma_select_user_eng
 {
 	struct sdma_rht_node *rht_node;
 	struct sdma_engine *sde = NULL;
-	const struct cpumask *current_mask = &current->cpus_allowed;
 	unsigned long cpu_id;
 
 	/*
 	 * To ensure that always the same sdma engine(s) will be
 	 * selected make sure the process is pinned to this CPU only.
 	 */
-	if (cpumask_weight(current_mask) != 1)
+	if (current->nr_cpus_allowed != 1)
 		goto out;
 
 	cpu_id = smp_processor_id();
Index: linux-4.19.25-rt16/drivers/infiniband/hw/qib/qib_file_ops.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/infiniband/hw/qib/qib_file_ops.c
+++ linux-4.19.25-rt16/drivers/infiniband/hw/qib/qib_file_ops.c
@@ -1142,7 +1142,7 @@ static __poll_t qib_poll(struct file *fp
 static void assign_ctxt_affinity(struct file *fp, struct qib_devdata *dd)
 {
 	struct qib_filedata *fd = fp->private_data;
-	const unsigned int weight = cpumask_weight(&current->cpus_allowed);
+	const unsigned int weight = current->nr_cpus_allowed;
 	const struct cpumask *local_mask = cpumask_of_pcibus(dd->pcidev->bus);
 	int local_cpu;
 
@@ -1623,9 +1623,8 @@ static int qib_assign_ctxt(struct file *
 		ret = find_free_ctxt(i_minor - 1, fp, uinfo);
 	else {
 		int unit;
-		const unsigned int cpu = cpumask_first(&current->cpus_allowed);
-		const unsigned int weight =
-			cpumask_weight(&current->cpus_allowed);
+		const unsigned int cpu = cpumask_first(current->cpus_ptr);
+		const unsigned int weight = current->nr_cpus_allowed;
 
 		if (weight == 1 && !test_bit(cpu, qib_cpulist))
 			if (!find_hca(cpu, &unit) && unit >= 0)
Index: linux-4.19.25-rt16/drivers/irqchip/irq-gic-v3-its.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/irqchip/irq-gic-v3-its.c
+++ linux-4.19.25-rt16/drivers/irqchip/irq-gic-v3-its.c
@@ -179,6 +179,7 @@ static DEFINE_RAW_SPINLOCK(vmovp_lock);
 static DEFINE_IDA(its_vpeid_ida);
 
 #define gic_data_rdist()		(raw_cpu_ptr(gic_rdists->rdist))
+#define gic_data_rdist_cpu(cpu)		(per_cpu_ptr(gic_rdists->rdist, cpu))
 #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
 #define gic_data_rdist_vlpi_base()	(gic_data_rdist_rd_base() + SZ_128K)
 
@@ -1631,7 +1632,7 @@ static void its_free_prop_table(struct p
 		   get_order(LPI_PROPBASE_SZ));
 }
 
-static int __init its_alloc_lpi_tables(void)
+static int __init its_alloc_lpi_prop_table(void)
 {
 	phys_addr_t paddr;
 
@@ -1979,30 +1980,47 @@ static u64 its_clear_vpend_valid(void __
 	return val;
 }
 
-static void its_cpu_init_lpis(void)
+static int __init allocate_lpi_tables(void)
 {
-	void __iomem *rbase = gic_data_rdist_rd_base();
-	struct page *pend_page;
-	u64 val, tmp;
+	int err, cpu;
 
-	/* If we didn't allocate the pending table yet, do it now */
-	pend_page = gic_data_rdist()->pend_page;
-	if (!pend_page) {
-		phys_addr_t paddr;
+	err = its_alloc_lpi_prop_table();
+	if (err)
+		return err;
+
+	/*
+	 * We allocate all the pending tables anyway, as we may have a
+	 * mix of RDs that have had LPIs enabled, and some that
+	 * don't. We'll free the unused ones as each CPU comes online.
+	 */
+	for_each_possible_cpu(cpu) {
+		struct page *pend_page;
 
 		pend_page = its_allocate_pending_table(GFP_NOWAIT);
 		if (!pend_page) {
-			pr_err("Failed to allocate PENDBASE for CPU%d\n",
-			       smp_processor_id());
-			return;
+			pr_err("Failed to allocate PENDBASE for CPU%d\n", cpu);
+			return -ENOMEM;
 		}
 
-		paddr = page_to_phys(pend_page);
-		pr_info("CPU%d: using LPI pending table @%pa\n",
-			smp_processor_id(), &paddr);
-		gic_data_rdist()->pend_page = pend_page;
+		gic_data_rdist_cpu(cpu)->pend_page = pend_page;
 	}
 
+	return 0;
+}
+
+static void its_cpu_init_lpis(void)
+{
+	void __iomem *rbase = gic_data_rdist_rd_base();
+	struct page *pend_page;
+	phys_addr_t paddr;
+	u64 val, tmp;
+
+	if (gic_data_rdist()->lpi_enabled)
+		return;
+
+	pend_page = gic_data_rdist()->pend_page;
+	paddr = page_to_phys(pend_page);
+
 	/* set PROPBASE */
 	val = (page_to_phys(gic_rdists->prop_page) |
 	       GICR_PROPBASER_InnerShareable |
@@ -2078,6 +2096,10 @@ static void its_cpu_init_lpis(void)
 
 	/* Make sure the GIC has seen the above */
 	dsb(sy);
+	gic_data_rdist()->lpi_enabled = true;
+	pr_info("GICv3: CPU%d: using LPI pending table @%pa\n",
+		smp_processor_id(),
+		&paddr);
 }
 
 static void its_cpu_init_collection(struct its_node *its)
@@ -3558,16 +3580,6 @@ static int redist_disable_lpis(void)
 	u64 timeout = USEC_PER_SEC;
 	u64 val;
 
-	/*
-	 * If coming via a CPU hotplug event, we don't need to disable
-	 * LPIs before trying to re-enable them. They are already
-	 * configured and all is well in the world. Detect this case
-	 * by checking the allocation of the pending table for the
-	 * current CPU.
-	 */
-	if (gic_data_rdist()->pend_page)
-		return 0;
-
 	if (!gic_rdists_supports_plpis()) {
 		pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
 		return -ENXIO;
@@ -3577,7 +3589,18 @@ static int redist_disable_lpis(void)
 	if (!(val & GICR_CTLR_ENABLE_LPIS))
 		return 0;
 
-	pr_warn("CPU%d: Booted with LPIs enabled, memory probably corrupted\n",
+	/*
+	 * If coming via a CPU hotplug event, we don't need to disable
+	 * LPIs before trying to re-enable them. They are already
+	 * configured and all is well in the world.
+	 */
+	if (gic_data_rdist()->lpi_enabled)
+		return 0;
+
+	/*
+	 * From that point on, we only try to do some damage control.
+	 */
+	pr_warn("GICv3: CPU%d: Booted with LPIs enabled, memory probably corrupted\n",
 		smp_processor_id());
 	add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
 
@@ -3833,7 +3856,8 @@ int __init its_init(struct fwnode_handle
 	}
 
 	gic_rdists = rdists;
-	err = its_alloc_lpi_tables();
+
+	err = allocate_lpi_tables();
 	if (err)
 		return err;
 
Index: linux-4.19.25-rt16/drivers/leds/trigger/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/drivers/leds/trigger/Kconfig
+++ linux-4.19.25-rt16/drivers/leds/trigger/Kconfig
@@ -63,6 +63,7 @@ config LEDS_TRIGGER_BACKLIGHT
 
 config LEDS_TRIGGER_CPU
 	bool "LED CPU Trigger"
+	depends on !PREEMPT_RT_BASE
 	help
 	  This allows LEDs to be controlled by active CPUs. This shows
 	  the active CPUs across an array of LEDs so you can see which
Index: linux-4.19.25-rt16/drivers/md/bcache/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/drivers/md/bcache/Kconfig
+++ linux-4.19.25-rt16/drivers/md/bcache/Kconfig
@@ -1,6 +1,7 @@
 
 config BCACHE
 	tristate "Block device as cache"
+	depends on !PREEMPT_RT_FULL
 	select CRC64
 	help
 	Allows a block device to be used as cache for other devices; uses
Index: linux-4.19.25-rt16/drivers/md/dm-rq.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/md/dm-rq.c
+++ linux-4.19.25-rt16/drivers/md/dm-rq.c
@@ -688,7 +688,6 @@ static void dm_old_request_fn(struct req
 		/* Establish tio->ti before queuing work (map_tio_request) */
 		tio->ti = ti;
 		kthread_queue_work(&md->kworker, &tio->work);
-		BUG_ON(!irqs_disabled());
 	}
 }
 
Index: linux-4.19.25-rt16/drivers/md/raid5.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/md/raid5.c
+++ linux-4.19.25-rt16/drivers/md/raid5.c
@@ -2069,8 +2069,9 @@ static void raid_run_ops(struct stripe_h
 	struct raid5_percpu *percpu;
 	unsigned long cpu;
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	percpu = per_cpu_ptr(conf->percpu, cpu);
+	spin_lock(&percpu->lock);
 	if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
 		ops_run_biofill(sh);
 		overlap_clear++;
@@ -2129,7 +2130,8 @@ static void raid_run_ops(struct stripe_h
 			if (test_and_clear_bit(R5_Overlap, &dev->flags))
 				wake_up(&sh->raid_conf->wait_for_overlap);
 		}
-	put_cpu();
+	spin_unlock(&percpu->lock);
+	put_cpu_light();
 }
 
 static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh)
@@ -6803,6 +6805,7 @@ static int raid456_cpu_up_prepare(unsign
 			__func__, cpu);
 		return -ENOMEM;
 	}
+	spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock);
 	return 0;
 }
 
@@ -6813,7 +6816,6 @@ static int raid5_alloc_percpu(struct r5c
 	conf->percpu = alloc_percpu(struct raid5_percpu);
 	if (!conf->percpu)
 		return -ENOMEM;
-
 	err = cpuhp_state_add_instance(CPUHP_MD_RAID5_PREPARE, &conf->node);
 	if (!err) {
 		conf->scribble_disks = max(conf->raid_disks,
Index: linux-4.19.25-rt16/drivers/md/raid5.h
===================================================================
--- linux-4.19.25-rt16.orig/drivers/md/raid5.h
+++ linux-4.19.25-rt16/drivers/md/raid5.h
@@ -637,6 +637,7 @@ struct r5conf {
 	int			recovery_disabled;
 	/* per cpu variables */
 	struct raid5_percpu {
+		spinlock_t	lock;		/* Protection for -RT */
 		struct page	*spare_page; /* Used when checking P/Q in raid6 */
 		struct flex_array *scribble;   /* space for constructing buffer
 					      * lists and performing address
Index: linux-4.19.25-rt16/drivers/misc/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/drivers/misc/Kconfig
+++ linux-4.19.25-rt16/drivers/misc/Kconfig
@@ -69,8 +69,7 @@ config ATMEL_TCB_CLKSRC
 	  are combined to make a single 32-bit timer.
 
 	  When GENERIC_CLOCKEVENTS is defined, the third timer channel
-	  may be used as a clock event device supporting oneshot mode
-	  (delays of up to two seconds) based on the 32 KiHz clock.
+	  may be used as a clock event device supporting oneshot mode.
 
 config ATMEL_TCB_CLKSRC_BLOCK
 	int
@@ -83,6 +82,15 @@ config ATMEL_TCB_CLKSRC_BLOCK
 	  TC can be used for other purposes, such as PWM generation and
 	  interval timing.
 
+config ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
+	bool "TC Block use 32 KiHz clock"
+	depends on ATMEL_TCB_CLKSRC
+	default y
+	help
+	  Select this to use 32 KiHz base clock rate as TC block clock
+	  source for clock events.
+
+
 config DUMMY_IRQ
 	tristate "Dummy IRQ handler"
 	default n
Index: linux-4.19.25-rt16/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
+++ linux-4.19.25-rt16/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
@@ -697,8 +697,8 @@ static void ezusb_req_ctx_wait(struct ez
 			while (!ctx->done.done && msecs--)
 				udelay(1000);
 		} else {
-			wait_event_interruptible(ctx->done.wait,
-						 ctx->done.done);
+			swait_event_interruptible_exclusive(ctx->done.wait,
+							    ctx->done.done);
 		}
 		break;
 	default:
Index: linux-4.19.25-rt16/drivers/of/base.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/of/base.c
+++ linux-4.19.25-rt16/drivers/of/base.c
@@ -130,31 +130,34 @@ static u32 phandle_cache_mask;
 /*
  * Caller must hold devtree_lock.
  */
-static void __of_free_phandle_cache(void)
+static struct device_node** __of_free_phandle_cache(void)
 {
 	u32 cache_entries = phandle_cache_mask + 1;
 	u32 k;
+	struct device_node **shadow;
 
 	if (!phandle_cache)
-		return;
+		return NULL;
 
 	for (k = 0; k < cache_entries; k++)
 		of_node_put(phandle_cache[k]);
 
-	kfree(phandle_cache);
+	shadow = phandle_cache;
 	phandle_cache = NULL;
+	return shadow;
 }
 
 int of_free_phandle_cache(void)
 {
 	unsigned long flags;
+	struct device_node **shadow;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 
-	__of_free_phandle_cache();
+	shadow = __of_free_phandle_cache();
 
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
-
+	kfree(shadow);
 	return 0;
 }
 #if !defined(CONFIG_MODULES)
@@ -189,10 +192,11 @@ void of_populate_phandle_cache(void)
 	u32 cache_entries;
 	struct device_node *np;
 	u32 phandles = 0;
+	struct device_node **shadow;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 
-	__of_free_phandle_cache();
+	shadow = __of_free_phandle_cache();
 
 	for_each_of_allnodes(np)
 		if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
@@ -200,12 +204,14 @@ void of_populate_phandle_cache(void)
 
 	if (!phandles)
 		goto out;
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
 	cache_entries = roundup_pow_of_two(phandles);
 	phandle_cache_mask = cache_entries - 1;
 
 	phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),
 				GFP_ATOMIC);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
 	if (!phandle_cache)
 		goto out;
 
@@ -217,6 +223,7 @@ void of_populate_phandle_cache(void)
 
 out:
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	kfree(shadow);
 }
 
 void __init of_core_init(void)
Index: linux-4.19.25-rt16/drivers/pci/switch/switchtec.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/pci/switch/switchtec.c
+++ linux-4.19.25-rt16/drivers/pci/switch/switchtec.c
@@ -43,10 +43,11 @@ struct switchtec_user {
 
 	enum mrpc_state state;
 
-	struct completion comp;
+	wait_queue_head_t cmd_comp;
 	struct kref kref;
 	struct list_head list;
 
+	bool cmd_done;
 	u32 cmd;
 	u32 status;
 	u32 return_code;
@@ -68,7 +69,7 @@ static struct switchtec_user *stuser_cre
 	stuser->stdev = stdev;
 	kref_init(&stuser->kref);
 	INIT_LIST_HEAD(&stuser->list);
-	init_completion(&stuser->comp);
+	init_waitqueue_head(&stuser->cmd_comp);
 	stuser->event_cnt = atomic_read(&stdev->event_cnt);
 
 	dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser);
@@ -151,7 +152,7 @@ static int mrpc_queue_cmd(struct switcht
 	kref_get(&stuser->kref);
 	stuser->read_len = sizeof(stuser->data);
 	stuser_set_state(stuser, MRPC_QUEUED);
-	init_completion(&stuser->comp);
+	stuser->cmd_done = false;
 	list_add_tail(&stuser->list, &stdev->mrpc_queue);
 
 	mrpc_cmd_submit(stdev);
@@ -188,7 +189,8 @@ static void mrpc_complete_cmd(struct swi
 		      stuser->read_len);
 
 out:
-	complete_all(&stuser->comp);
+	stuser->cmd_done = true;
+	wake_up_interruptible(&stuser->cmd_comp);
 	list_del_init(&stuser->list);
 	stuser_put(stuser);
 	stdev->mrpc_busy = 0;
@@ -458,10 +460,11 @@ static ssize_t switchtec_dev_read(struct
 	mutex_unlock(&stdev->mrpc_mutex);
 
 	if (filp->f_flags & O_NONBLOCK) {
-		if (!try_wait_for_completion(&stuser->comp))
+		if (!READ_ONCE(stuser->cmd_done))
 			return -EAGAIN;
 	} else {
-		rc = wait_for_completion_interruptible(&stuser->comp);
+		rc = wait_event_interruptible(stuser->cmd_comp,
+					      stuser->cmd_done);
 		if (rc < 0)
 			return rc;
 	}
@@ -509,7 +512,7 @@ static __poll_t switchtec_dev_poll(struc
 	struct switchtec_dev *stdev = stuser->stdev;
 	__poll_t ret = 0;
 
-	poll_wait(filp, &stuser->comp.wait, wait);
+	poll_wait(filp, &stuser->cmd_comp, wait);
 	poll_wait(filp, &stdev->event_wq, wait);
 
 	if (lock_mutex_and_test_alive(stdev))
@@ -517,7 +520,7 @@ static __poll_t switchtec_dev_poll(struc
 
 	mutex_unlock(&stdev->mrpc_mutex);
 
-	if (try_wait_for_completion(&stuser->comp))
+	if (READ_ONCE(stuser->cmd_done))
 		ret |= EPOLLIN | EPOLLRDNORM;
 
 	if (stuser->event_cnt != atomic_read(&stdev->event_cnt))
@@ -1041,7 +1044,8 @@ static void stdev_kill(struct switchtec_
 
 	/* Wake up and kill any users waiting on an MRPC request */
 	list_for_each_entry_safe(stuser, tmpuser, &stdev->mrpc_queue, list) {
-		complete_all(&stuser->comp);
+		stuser->cmd_done = true;
+		wake_up_interruptible(&stuser->cmd_comp);
 		list_del_init(&stuser->list);
 		stuser_put(stuser);
 	}
Index: linux-4.19.25-rt16/drivers/scsi/fcoe/fcoe.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/scsi/fcoe/fcoe.c
+++ linux-4.19.25-rt16/drivers/scsi/fcoe/fcoe.c
@@ -1459,11 +1459,11 @@ err2:
 static int fcoe_alloc_paged_crc_eof(struct sk_buff *skb, int tlen)
 {
 	struct fcoe_percpu_s *fps;
-	int rc;
+	int rc, cpu = get_cpu_light();
 
-	fps = &get_cpu_var(fcoe_percpu);
+	fps = &per_cpu(fcoe_percpu, cpu);
 	rc = fcoe_get_paged_crc_eof(skb, tlen, fps);
-	put_cpu_var(fcoe_percpu);
+	put_cpu_light();
 
 	return rc;
 }
@@ -1650,11 +1650,11 @@ static inline int fcoe_filter_frames(str
 		return 0;
 	}
 
-	stats = per_cpu_ptr(lport->stats, get_cpu());
+	stats = per_cpu_ptr(lport->stats, get_cpu_light());
 	stats->InvalidCRCCount++;
 	if (stats->InvalidCRCCount < 5)
 		printk(KERN_WARNING "fcoe: dropping frame with CRC error\n");
-	put_cpu();
+	put_cpu_light();
 	return -EINVAL;
 }
 
@@ -1697,7 +1697,7 @@ static void fcoe_recv_frame(struct sk_bu
 	 */
 	hp = (struct fcoe_hdr *) skb_network_header(skb);
 
-	stats = per_cpu_ptr(lport->stats, get_cpu());
+	stats = per_cpu_ptr(lport->stats, get_cpu_light());
 	if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
 		if (stats->ErrorFrames < 5)
 			printk(KERN_WARNING "fcoe: FCoE version "
@@ -1729,13 +1729,13 @@ static void fcoe_recv_frame(struct sk_bu
 		goto drop;
 
 	if (!fcoe_filter_frames(lport, fp)) {
-		put_cpu();
+		put_cpu_light();
 		fc_exch_recv(lport, fp);
 		return;
 	}
 drop:
 	stats->ErrorFrames++;
-	put_cpu();
+	put_cpu_light();
 	kfree_skb(skb);
 }
 
Index: linux-4.19.25-rt16/drivers/scsi/fcoe/fcoe_ctlr.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/scsi/fcoe/fcoe_ctlr.c
+++ linux-4.19.25-rt16/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -838,7 +838,7 @@ static unsigned long fcoe_ctlr_age_fcfs(
 
 	INIT_LIST_HEAD(&del_list);
 
-	stats = per_cpu_ptr(fip->lp->stats, get_cpu());
+	stats = per_cpu_ptr(fip->lp->stats, get_cpu_light());
 
 	list_for_each_entry_safe(fcf, next, &fip->fcfs, list) {
 		deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2;
@@ -874,7 +874,7 @@ static unsigned long fcoe_ctlr_age_fcfs(
 				sel_time = fcf->time;
 		}
 	}
-	put_cpu();
+	put_cpu_light();
 
 	list_for_each_entry_safe(fcf, next, &del_list, list) {
 		/* Removes fcf from current list */
Index: linux-4.19.25-rt16/drivers/scsi/libfc/fc_exch.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/scsi/libfc/fc_exch.c
+++ linux-4.19.25-rt16/drivers/scsi/libfc/fc_exch.c
@@ -833,10 +833,10 @@ static struct fc_exch *fc_exch_em_alloc(
 	}
 	memset(ep, 0, sizeof(*ep));
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	pool = per_cpu_ptr(mp->pool, cpu);
 	spin_lock_bh(&pool->lock);
-	put_cpu();
+	put_cpu_light();
 
 	/* peek cache of free slot */
 	if (pool->left != FC_XID_UNKNOWN) {
Index: linux-4.19.25-rt16/drivers/staging/android/vsoc.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/staging/android/vsoc.c
+++ linux-4.19.25-rt16/drivers/staging/android/vsoc.c
@@ -437,12 +437,10 @@ static int handle_vsoc_cond_wait(struct
 			return -EINVAL;
 		wake_time = ktime_set(arg->wake_time_sec, arg->wake_time_nsec);
 
-		hrtimer_init_on_stack(&to->timer, CLOCK_MONOTONIC,
-				      HRTIMER_MODE_ABS);
+		hrtimer_init_sleeper_on_stack(to, CLOCK_MONOTONIC,
+					      HRTIMER_MODE_ABS, current);
 		hrtimer_set_expires_range_ns(&to->timer, wake_time,
 					     current->timer_slack_ns);
-
-		hrtimer_init_sleeper(to, current);
 	}
 
 	while (1) {
Index: linux-4.19.25-rt16/drivers/thermal/x86_pkg_temp_thermal.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/thermal/x86_pkg_temp_thermal.c
+++ linux-4.19.25-rt16/drivers/thermal/x86_pkg_temp_thermal.c
@@ -29,6 +29,7 @@
 #include <linux/pm.h>
 #include <linux/thermal.h>
 #include <linux/debugfs.h>
+#include <linux/swork.h>
 #include <asm/cpu_device_id.h>
 #include <asm/mce.h>
 
@@ -329,7 +330,7 @@ static void pkg_thermal_schedule_work(in
 	schedule_delayed_work_on(cpu, work, ms);
 }
 
-static int pkg_thermal_notify(u64 msr_val)
+static void pkg_thermal_notify_work(struct swork_event *event)
 {
 	int cpu = smp_processor_id();
 	struct pkg_device *pkgdev;
@@ -348,9 +349,47 @@ static int pkg_thermal_notify(u64 msr_va
 	}
 
 	spin_unlock_irqrestore(&pkg_temp_lock, flags);
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static struct swork_event notify_work;
+
+static int pkg_thermal_notify_work_init(void)
+{
+	int err;
+
+	err = swork_get();
+	if (err)
+		return err;
+
+	INIT_SWORK(&notify_work, pkg_thermal_notify_work);
 	return 0;
 }
 
+static void pkg_thermal_notify_work_cleanup(void)
+{
+	swork_put();
+}
+
+static int pkg_thermal_notify(u64 msr_val)
+{
+	swork_queue(&notify_work);
+	return 0;
+}
+
+#else  /* !CONFIG_PREEMPT_RT_FULL */
+
+static int pkg_thermal_notify_work_init(void) { return 0; }
+
+static void pkg_thermal_notify_work_cleanup(void) {  }
+
+static int pkg_thermal_notify(u64 msr_val)
+{
+	pkg_thermal_notify_work(NULL);
+	return 0;
+}
+#endif /* CONFIG_PREEMPT_RT_FULL */
+
 static int pkg_temp_thermal_device_add(unsigned int cpu)
 {
 	int pkgid = topology_logical_package_id(cpu);
@@ -515,11 +554,16 @@ static int __init pkg_temp_thermal_init(
 	if (!x86_match_cpu(pkg_temp_thermal_ids))
 		return -ENODEV;
 
+	if (!pkg_thermal_notify_work_init())
+		return -ENODEV;
+
 	max_packages = topology_max_packages();
 	packages = kcalloc(max_packages, sizeof(struct pkg_device *),
 			   GFP_KERNEL);
-	if (!packages)
-		return -ENOMEM;
+	if (!packages) {
+		ret = -ENOMEM;
+		goto err;
+	}
 
 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "thermal/x86_pkg:online",
 				pkg_thermal_cpu_online,	pkg_thermal_cpu_offline);
@@ -537,6 +581,7 @@ static int __init pkg_temp_thermal_init(
 	return 0;
 
 err:
+	pkg_thermal_notify_work_cleanup();
 	kfree(packages);
 	return ret;
 }
@@ -550,6 +595,7 @@ static void __exit pkg_temp_thermal_exit
 	cpuhp_remove_state(pkg_thermal_hp_state);
 	debugfs_remove_recursive(debugfs);
 	kfree(packages);
+	pkg_thermal_notify_work_cleanup();
 }
 module_exit(pkg_temp_thermal_exit)
 
Index: linux-4.19.25-rt16/drivers/tty/serial/8250/8250_core.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/tty/serial/8250/8250_core.c
+++ linux-4.19.25-rt16/drivers/tty/serial/8250/8250_core.c
@@ -54,7 +54,16 @@ static struct uart_driver serial8250_reg
 
 static unsigned int skip_txen_test; /* force skip of txen test at init time */
 
-#define PASS_LIMIT	512
+/*
+ * On -rt we can have a more delays, and legitimately
+ * so - so don't drop work spuriously and spam the
+ * syslog:
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define PASS_LIMIT	1000000
+#else
+# define PASS_LIMIT	512
+#endif
 
 #include <asm/serial.h>
 /*
Index: linux-4.19.25-rt16/drivers/tty/serial/8250/8250_port.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/tty/serial/8250/8250_port.c
+++ linux-4.19.25-rt16/drivers/tty/serial/8250/8250_port.c
@@ -31,6 +31,7 @@
 #include <linux/nmi.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/kdb.h>
 #include <linux/uaccess.h>
 #include <linux/pm_runtime.h>
 #include <linux/ktime.h>
@@ -3239,9 +3240,9 @@ void serial8250_console_write(struct uar
 
 	serial8250_rpm_get(up);
 
-	if (port->sysrq)
+	if (port->sysrq || oops_in_progress)
 		locked = 0;
-	else if (oops_in_progress)
+	else if (in_kdb_printk())
 		locked = spin_trylock_irqsave(&port->lock, flags);
 	else
 		spin_lock_irqsave(&port->lock, flags);
Index: linux-4.19.25-rt16/drivers/tty/serial/amba-pl011.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/tty/serial/amba-pl011.c
+++ linux-4.19.25-rt16/drivers/tty/serial/amba-pl011.c
@@ -2211,18 +2211,24 @@ pl011_console_write(struct console *co,
 {
 	struct uart_amba_port *uap = amba_ports[co->index];
 	unsigned int old_cr = 0, new_cr;
-	unsigned long flags;
+	unsigned long flags = 0;
 	int locked = 1;
 
 	clk_enable(uap->clk);
 
-	local_irq_save(flags);
+	/*
+	 * local_irq_save(flags);
+	 *
+	 * This local_irq_save() is nonsense. If we come in via sysrq
+	 * handling then interrupts are already disabled. Aside of
+	 * that the port.sysrq check is racy on SMP regardless.
+	*/
 	if (uap->port.sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&uap->port.lock);
+		locked = spin_trylock_irqsave(&uap->port.lock, flags);
 	else
-		spin_lock(&uap->port.lock);
+		spin_lock_irqsave(&uap->port.lock, flags);
 
 	/*
 	 *	First save the CR then disable the interrupts
@@ -2248,8 +2254,7 @@ pl011_console_write(struct console *co,
 		pl011_write(old_cr, uap, REG_CR);
 
 	if (locked)
-		spin_unlock(&uap->port.lock);
-	local_irq_restore(flags);
+		spin_unlock_irqrestore(&uap->port.lock, flags);
 
 	clk_disable(uap->clk);
 }
Index: linux-4.19.25-rt16/drivers/tty/serial/omap-serial.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/tty/serial/omap-serial.c
+++ linux-4.19.25-rt16/drivers/tty/serial/omap-serial.c
@@ -1307,13 +1307,10 @@ serial_omap_console_write(struct console
 
 	pm_runtime_get_sync(up->dev);
 
-	local_irq_save(flags);
-	if (up->port.sysrq)
-		locked = 0;
-	else if (oops_in_progress)
-		locked = spin_trylock(&up->port.lock);
+	if (up->port.sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
 	else
-		spin_lock(&up->port.lock);
+		spin_lock_irqsave(&up->port.lock, flags);
 
 	/*
 	 * First save the IER then disable the interrupts
@@ -1342,8 +1339,7 @@ serial_omap_console_write(struct console
 	pm_runtime_mark_last_busy(up->dev);
 	pm_runtime_put_autosuspend(up->dev);
 	if (locked)
-		spin_unlock(&up->port.lock);
-	local_irq_restore(flags);
+		spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static int __init
Index: linux-4.19.25-rt16/drivers/tty/sysrq.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/tty/sysrq.c
+++ linux-4.19.25-rt16/drivers/tty/sysrq.c
@@ -215,7 +215,7 @@ static struct sysrq_key_op sysrq_showloc
 #endif
 
 #ifdef CONFIG_SMP
-static DEFINE_SPINLOCK(show_lock);
+static DEFINE_RAW_SPINLOCK(show_lock);
 
 static void showacpu(void *dummy)
 {
@@ -225,10 +225,10 @@ static void showacpu(void *dummy)
 	if (idle_cpu(smp_processor_id()))
 		return;
 
-	spin_lock_irqsave(&show_lock, flags);
+	raw_spin_lock_irqsave(&show_lock, flags);
 	pr_info("CPU%d:\n", smp_processor_id());
 	show_stack(NULL, NULL);
-	spin_unlock_irqrestore(&show_lock, flags);
+	raw_spin_unlock_irqrestore(&show_lock, flags);
 }
 
 static void sysrq_showregs_othercpus(struct work_struct *dummy)
Index: linux-4.19.25-rt16/drivers/usb/core/hcd.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/usb/core/hcd.c
+++ linux-4.19.25-rt16/drivers/usb/core/hcd.c
@@ -1738,7 +1738,6 @@ static void __usb_hcd_giveback_urb(struc
 	struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
 	struct usb_anchor *anchor = urb->anchor;
 	int status = urb->unlinked;
-	unsigned long flags;
 
 	urb->hcpriv = NULL;
 	if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
@@ -1766,9 +1765,7 @@ static void __usb_hcd_giveback_urb(struc
 	 * and no one may trigger the above deadlock situation when
 	 * running complete() in tasklet.
 	 */
-	local_irq_save(flags);
 	urb->complete(urb);
-	local_irq_restore(flags);
 
 	usb_anchor_resume_wakeups(anchor);
 	atomic_dec(&urb->use_count);
Index: linux-4.19.25-rt16/drivers/usb/gadget/function/f_fs.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/usb/gadget/function/f_fs.c
+++ linux-4.19.25-rt16/drivers/usb/gadget/function/f_fs.c
@@ -1624,7 +1624,7 @@ static void ffs_data_put(struct ffs_data
 		pr_info("%s(): freeing\n", __func__);
 		ffs_data_clear(ffs);
 		BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
-		       waitqueue_active(&ffs->ep0req_completion.wait) ||
+		       swait_active(&ffs->ep0req_completion.wait) ||
 		       waitqueue_active(&ffs->wait));
 		destroy_workqueue(ffs->io_completion_wq);
 		kfree(ffs->dev_name);
Index: linux-4.19.25-rt16/drivers/usb/gadget/legacy/inode.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/usb/gadget/legacy/inode.c
+++ linux-4.19.25-rt16/drivers/usb/gadget/legacy/inode.c
@@ -343,7 +343,7 @@ ep_io (struct ep_data *epdata, void *buf
 	spin_unlock_irq (&epdata->dev->lock);
 
 	if (likely (value == 0)) {
-		value = wait_event_interruptible (done.wait, done.done);
+		value = swait_event_interruptible_exclusive(done.wait, done.done);
 		if (value != 0) {
 			spin_lock_irq (&epdata->dev->lock);
 			if (likely (epdata->ep != NULL)) {
@@ -352,7 +352,7 @@ ep_io (struct ep_data *epdata, void *buf
 				usb_ep_dequeue (epdata->ep, epdata->req);
 				spin_unlock_irq (&epdata->dev->lock);
 
-				wait_event (done.wait, done.done);
+				swait_event_exclusive(done.wait, done.done);
 				if (epdata->status == -ECONNRESET)
 					epdata->status = -EINTR;
 			} else {
Index: linux-4.19.25-rt16/drivers/watchdog/watchdog_dev.c
===================================================================
--- linux-4.19.25-rt16.orig/drivers/watchdog/watchdog_dev.c
+++ linux-4.19.25-rt16/drivers/watchdog/watchdog_dev.c
@@ -147,7 +147,7 @@ static inline void watchdog_update_worke
 		ktime_t t = watchdog_next_keepalive(wdd);
 
 		if (t > 0)
-			hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL);
+			hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL_HARD);
 	} else {
 		hrtimer_cancel(&wd_data->timer);
 	}
@@ -166,7 +166,7 @@ static int __watchdog_ping(struct watchd
 	if (ktime_after(earliest_keepalive, now)) {
 		hrtimer_start(&wd_data->timer,
 			      ktime_sub(earliest_keepalive, now),
-			      HRTIMER_MODE_REL);
+			      HRTIMER_MODE_REL_HARD);
 		return 0;
 	}
 
@@ -945,7 +945,7 @@ static int watchdog_cdev_register(struct
 		return -ENODEV;
 
 	kthread_init_work(&wd_data->work, watchdog_ping_work);
-	hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	wd_data->timer.function = watchdog_timer_expired;
 
 	if (wdd->id == 0) {
@@ -992,7 +992,7 @@ static int watchdog_cdev_register(struct
 		__module_get(wdd->ops->owner);
 		kref_get(&wd_data->kref);
 		if (handle_boot_enabled)
-			hrtimer_start(&wd_data->timer, 0, HRTIMER_MODE_REL);
+			hrtimer_start(&wd_data->timer, 0, HRTIMER_MODE_REL_HARD);
 		else
 			pr_info("watchdog%d running and kernel based pre-userspace handler disabled\n",
 				wdd->id);
Index: linux-4.19.25-rt16/fs/aio.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/aio.c
+++ linux-4.19.25-rt16/fs/aio.c
@@ -42,6 +42,7 @@
 #include <linux/ramfs.h>
 #include <linux/percpu-refcount.h>
 #include <linux/mount.h>
+#include <linux/swork.h>
 
 #include <asm/kmap_types.h>
 #include <linux/uaccess.h>
@@ -121,6 +122,7 @@ struct kioctx {
 	long			nr_pages;
 
 	struct rcu_work		free_rwork;	/* see free_ioctx() */
+	struct swork_event	free_swork;	/* see free_ioctx() */
 
 	/*
 	 * signals when all in-flight requests are done
@@ -255,6 +257,7 @@ static int __init aio_setup(void)
 		.mount		= aio_mount,
 		.kill_sb	= kill_anon_super,
 	};
+	BUG_ON(swork_get());
 	aio_mnt = kern_mount(&aio_fs);
 	if (IS_ERR(aio_mnt))
 		panic("Failed to create aio fs mount.");
@@ -596,9 +599,9 @@ static void free_ioctx_reqs(struct percp
  * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
  * now it's safe to cancel any that need to be.
  */
-static void free_ioctx_users(struct percpu_ref *ref)
+static void free_ioctx_users_work(struct swork_event *sev)
 {
-	struct kioctx *ctx = container_of(ref, struct kioctx, users);
+	struct kioctx *ctx = container_of(sev, struct kioctx, free_swork);
 	struct aio_kiocb *req;
 
 	spin_lock_irq(&ctx->ctx_lock);
@@ -616,6 +619,14 @@ static void free_ioctx_users(struct perc
 	percpu_ref_put(&ctx->reqs);
 }
 
+static void free_ioctx_users(struct percpu_ref *ref)
+{
+	struct kioctx *ctx = container_of(ref, struct kioctx, users);
+
+	INIT_SWORK(&ctx->free_swork, free_ioctx_users_work);
+	swork_queue(&ctx->free_swork);
+}
+
 static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
 {
 	unsigned i, new_nr;
Index: linux-4.19.25-rt16/fs/autofs/expire.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/autofs/expire.c
+++ linux-4.19.25-rt16/fs/autofs/expire.c
@@ -8,6 +8,7 @@
  * option, any later version, incorporated herein by reference.
  */
 
+#include <linux/delay.h>
 #include "autofs_i.h"
 
 /* Check if a dentry can be expired */
@@ -153,7 +154,7 @@ again:
 			parent = p->d_parent;
 			if (!spin_trylock(&parent->d_lock)) {
 				spin_unlock(&p->d_lock);
-				cpu_relax();
+				cpu_chill();
 				goto relock;
 			}
 			spin_unlock(&p->d_lock);
Index: linux-4.19.25-rt16/fs/buffer.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/buffer.c
+++ linux-4.19.25-rt16/fs/buffer.c
@@ -274,8 +274,7 @@ static void end_buffer_async_read(struct
 	 * decide that the page is now completely done.
 	 */
 	first = page_buffers(page);
-	local_irq_save(flags);
-	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+	flags = bh_uptodate_lock_irqsave(first);
 	clear_buffer_async_read(bh);
 	unlock_buffer(bh);
 	tmp = bh;
@@ -288,8 +287,7 @@ static void end_buffer_async_read(struct
 		}
 		tmp = tmp->b_this_page;
 	} while (tmp != bh);
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
+	bh_uptodate_unlock_irqrestore(first, flags);
 
 	/*
 	 * If none of the buffers had errors and they are all
@@ -301,9 +299,7 @@ static void end_buffer_async_read(struct
 	return;
 
 still_busy:
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	return;
+	bh_uptodate_unlock_irqrestore(first, flags);
 }
 
 /*
@@ -330,8 +326,7 @@ void end_buffer_async_write(struct buffe
 	}
 
 	first = page_buffers(page);
-	local_irq_save(flags);
-	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+	flags = bh_uptodate_lock_irqsave(first);
 
 	clear_buffer_async_write(bh);
 	unlock_buffer(bh);
@@ -343,15 +338,12 @@ void end_buffer_async_write(struct buffe
 		}
 		tmp = tmp->b_this_page;
 	}
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
+	bh_uptodate_unlock_irqrestore(first, flags);
 	end_page_writeback(page);
 	return;
 
 still_busy:
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	return;
+	bh_uptodate_unlock_irqrestore(first, flags);
 }
 EXPORT_SYMBOL(end_buffer_async_write);
 
@@ -3368,6 +3360,7 @@ struct buffer_head *alloc_buffer_head(gf
 	struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags);
 	if (ret) {
 		INIT_LIST_HEAD(&ret->b_assoc_buffers);
+		buffer_head_init_locks(ret);
 		preempt_disable();
 		__this_cpu_inc(bh_accounting.nr);
 		recalc_bh_state();
Index: linux-4.19.25-rt16/fs/cifs/readdir.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/cifs/readdir.c
+++ linux-4.19.25-rt16/fs/cifs/readdir.c
@@ -80,7 +80,7 @@ cifs_prime_dcache(struct dentry *parent,
 	struct inode *inode;
 	struct super_block *sb = parent->d_sb;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
 
Index: linux-4.19.25-rt16/fs/dcache.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/dcache.c
+++ linux-4.19.25-rt16/fs/dcache.c
@@ -2400,9 +2400,10 @@ EXPORT_SYMBOL(d_rehash);
 static inline unsigned start_dir_add(struct inode *dir)
 {
 
+	preempt_disable_rt();
 	for (;;) {
-		unsigned n = dir->i_dir_seq;
-		if (!(n & 1) && cmpxchg(&dir->i_dir_seq, n, n + 1) == n)
+		unsigned n = dir->__i_dir_seq;
+		if (!(n & 1) && cmpxchg(&dir->__i_dir_seq, n, n + 1) == n)
 			return n;
 		cpu_relax();
 	}
@@ -2410,26 +2411,30 @@ static inline unsigned start_dir_add(str
 
 static inline void end_dir_add(struct inode *dir, unsigned n)
 {
-	smp_store_release(&dir->i_dir_seq, n + 2);
+	smp_store_release(&dir->__i_dir_seq, n + 2);
+	preempt_enable_rt();
 }
 
 static void d_wait_lookup(struct dentry *dentry)
 {
-	if (d_in_lookup(dentry)) {
-		DECLARE_WAITQUEUE(wait, current);
-		add_wait_queue(dentry->d_wait, &wait);
-		do {
-			set_current_state(TASK_UNINTERRUPTIBLE);
-			spin_unlock(&dentry->d_lock);
-			schedule();
-			spin_lock(&dentry->d_lock);
-		} while (d_in_lookup(dentry));
-	}
+	struct swait_queue __wait;
+
+	if (!d_in_lookup(dentry))
+		return;
+
+	INIT_LIST_HEAD(&__wait.task_list);
+	do {
+		prepare_to_swait_exclusive(dentry->d_wait, &__wait, TASK_UNINTERRUPTIBLE);
+		spin_unlock(&dentry->d_lock);
+		schedule();
+		spin_lock(&dentry->d_lock);
+	} while (d_in_lookup(dentry));
+	finish_swait(dentry->d_wait, &__wait);
 }
 
 struct dentry *d_alloc_parallel(struct dentry *parent,
 				const struct qstr *name,
-				wait_queue_head_t *wq)
+				struct swait_queue_head *wq)
 {
 	unsigned int hash = name->hash;
 	struct hlist_bl_head *b = in_lookup_hash(parent, hash);
@@ -2443,7 +2448,7 @@ struct dentry *d_alloc_parallel(struct d
 
 retry:
 	rcu_read_lock();
-	seq = smp_load_acquire(&parent->d_inode->i_dir_seq);
+	seq = smp_load_acquire(&parent->d_inode->__i_dir_seq);
 	r_seq = read_seqbegin(&rename_lock);
 	dentry = __d_lookup_rcu(parent, name, &d_seq);
 	if (unlikely(dentry)) {
@@ -2471,7 +2476,7 @@ retry:
 	}
 
 	hlist_bl_lock(b);
-	if (unlikely(READ_ONCE(parent->d_inode->i_dir_seq) != seq)) {
+	if (unlikely(READ_ONCE(parent->d_inode->__i_dir_seq) != seq)) {
 		hlist_bl_unlock(b);
 		rcu_read_unlock();
 		goto retry;
@@ -2544,7 +2549,7 @@ void __d_lookup_done(struct dentry *dent
 	hlist_bl_lock(b);
 	dentry->d_flags &= ~DCACHE_PAR_LOOKUP;
 	__hlist_bl_del(&dentry->d_u.d_in_lookup_hash);
-	wake_up_all(dentry->d_wait);
+	swake_up_all(dentry->d_wait);
 	dentry->d_wait = NULL;
 	hlist_bl_unlock(b);
 	INIT_HLIST_NODE(&dentry->d_u.d_alias);
@@ -3058,6 +3063,8 @@ __setup("dhash_entries=", set_dhash_entr
 
 static void __init dcache_init_early(void)
 {
+	unsigned int loop;
+
 	/* If hashes are distributed across NUMA nodes, defer
 	 * hash allocation until vmalloc space is available.
 	 */
@@ -3074,11 +3081,16 @@ static void __init dcache_init_early(voi
 					NULL,
 					0,
 					0);
+
+	for (loop = 0; loop < (1U << d_hash_shift); loop++)
+		INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
+
 	d_hash_shift = 32 - d_hash_shift;
 }
 
 static void __init dcache_init(void)
 {
+	unsigned int loop;
 	/*
 	 * A constructor could be added for stable state like the lists,
 	 * but it is probably not worth it because of the cache nature
@@ -3102,6 +3114,10 @@ static void __init dcache_init(void)
 					NULL,
 					0,
 					0);
+
+	for (loop = 0; loop < (1U << d_hash_shift); loop++)
+		INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
+
 	d_hash_shift = 32 - d_hash_shift;
 }
 
Index: linux-4.19.25-rt16/fs/eventpoll.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/eventpoll.c
+++ linux-4.19.25-rt16/fs/eventpoll.c
@@ -571,12 +571,12 @@ static int ep_poll_wakeup_proc(void *pri
 
 static void ep_poll_safewake(wait_queue_head_t *wq)
 {
-	int this_cpu = get_cpu();
+	int this_cpu = get_cpu_light();
 
 	ep_call_nested(&poll_safewake_ncalls, EP_MAX_NESTS,
 		       ep_poll_wakeup_proc, NULL, wq, (void *) (long) this_cpu);
 
-	put_cpu();
+	put_cpu_light();
 }
 
 #else
Index: linux-4.19.25-rt16/fs/exec.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/exec.c
+++ linux-4.19.25-rt16/fs/exec.c
@@ -1028,12 +1028,14 @@ static int exec_mmap(struct mm_struct *m
 		}
 	}
 	task_lock(tsk);
+	preempt_disable_rt();
 	active_mm = tsk->active_mm;
 	tsk->mm = mm;
 	tsk->active_mm = mm;
 	activate_mm(active_mm, mm);
 	tsk->mm->vmacache_seqnum = 0;
 	vmacache_flush(tsk);
+	preempt_enable_rt();
 	task_unlock(tsk);
 	if (old_mm) {
 		up_read(&old_mm->mmap_sem);
Index: linux-4.19.25-rt16/fs/ext4/page-io.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/ext4/page-io.c
+++ linux-4.19.25-rt16/fs/ext4/page-io.c
@@ -95,8 +95,7 @@ static void ext4_finish_bio(struct bio *
 		 * We check all buffers in the page under BH_Uptodate_Lock
 		 * to avoid races with other end io clearing async_write flags
 		 */
-		local_irq_save(flags);
-		bit_spin_lock(BH_Uptodate_Lock, &head->b_state);
+		flags = bh_uptodate_lock_irqsave(head);
 		do {
 			if (bh_offset(bh) < bio_start ||
 			    bh_offset(bh) + bh->b_size > bio_end) {
@@ -108,8 +107,7 @@ static void ext4_finish_bio(struct bio *
 			if (bio->bi_status)
 				buffer_io_error(bh);
 		} while ((bh = bh->b_this_page) != head);
-		bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
-		local_irq_restore(flags);
+		bh_uptodate_unlock_irqrestore(head, flags);
 		if (!under_io) {
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 			if (data_page)
Index: linux-4.19.25-rt16/fs/fscache/cookie.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/fscache/cookie.c
+++ linux-4.19.25-rt16/fs/fscache/cookie.c
@@ -962,3 +962,11 @@ inconsistent:
 	return -ESTALE;
 }
 EXPORT_SYMBOL(__fscache_check_consistency);
+
+void __init fscache_cookie_init(void)
+{
+	int i;
+
+	for (i = 0; i < (1 << fscache_cookie_hash_shift) - 1; i++)
+		INIT_HLIST_BL_HEAD(&fscache_cookie_hash[i]);
+}
Index: linux-4.19.25-rt16/fs/fscache/main.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/fscache/main.c
+++ linux-4.19.25-rt16/fs/fscache/main.c
@@ -149,6 +149,7 @@ static int __init fscache_init(void)
 		ret = -ENOMEM;
 		goto error_cookie_jar;
 	}
+	fscache_cookie_init();
 
 	fscache_root = kobject_create_and_add("fscache", kernel_kobj);
 	if (!fscache_root)
Index: linux-4.19.25-rt16/fs/fuse/dir.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/fuse/dir.c
+++ linux-4.19.25-rt16/fs/fuse/dir.c
@@ -1203,7 +1203,7 @@ static int fuse_direntplus_link(struct f
 	struct inode *dir = d_inode(parent);
 	struct fuse_conn *fc;
 	struct inode *inode;
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	if (!o->nodeid) {
 		/*
Index: linux-4.19.25-rt16/fs/inode.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/inode.c
+++ linux-4.19.25-rt16/fs/inode.c
@@ -155,7 +155,7 @@ int inode_init_always(struct super_block
 	inode->i_bdev = NULL;
 	inode->i_cdev = NULL;
 	inode->i_link = NULL;
-	inode->i_dir_seq = 0;
+	inode->__i_dir_seq = 0;
 	inode->i_rdev = 0;
 	inode->dirtied_when = 0;
 
Index: linux-4.19.25-rt16/fs/libfs.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/libfs.c
+++ linux-4.19.25-rt16/fs/libfs.c
@@ -90,7 +90,7 @@ static struct dentry *next_positive(stru
 				    struct list_head *from,
 				    int count)
 {
-	unsigned *seq = &parent->d_inode->i_dir_seq, n;
+	unsigned *seq = &parent->d_inode->__i_dir_seq, n;
 	struct dentry *res;
 	struct list_head *p;
 	bool skipped;
@@ -123,8 +123,9 @@ retry:
 static void move_cursor(struct dentry *cursor, struct list_head *after)
 {
 	struct dentry *parent = cursor->d_parent;
-	unsigned n, *seq = &parent->d_inode->i_dir_seq;
+	unsigned n, *seq = &parent->d_inode->__i_dir_seq;
 	spin_lock(&parent->d_lock);
+	preempt_disable_rt();
 	for (;;) {
 		n = *seq;
 		if (!(n & 1) && cmpxchg(seq, n, n + 1) == n)
@@ -137,6 +138,7 @@ static void move_cursor(struct dentry *c
 	else
 		list_add_tail(&cursor->d_child, &parent->d_subdirs);
 	smp_store_release(seq, n + 2);
+	preempt_enable_rt();
 	spin_unlock(&parent->d_lock);
 }
 
Index: linux-4.19.25-rt16/fs/locks.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/locks.c
+++ linux-4.19.25-rt16/fs/locks.c
@@ -936,7 +936,7 @@ static int flock_lock_inode(struct inode
 			return -ENOMEM;
 	}
 
-	percpu_down_read_preempt_disable(&file_rwsem);
+	percpu_down_read(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	if (request->fl_flags & FL_ACCESS)
 		goto find_conflict;
@@ -977,7 +977,7 @@ find_conflict:
 
 out:
 	spin_unlock(&ctx->flc_lock);
-	percpu_up_read_preempt_enable(&file_rwsem);
+	percpu_up_read(&file_rwsem);
 	if (new_fl)
 		locks_free_lock(new_fl);
 	locks_dispose_list(&dispose);
@@ -1015,7 +1015,7 @@ static int posix_lock_inode(struct inode
 		new_fl2 = locks_alloc_lock();
 	}
 
-	percpu_down_read_preempt_disable(&file_rwsem);
+	percpu_down_read(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	/*
 	 * New lock request. Walk all POSIX locks and look for conflicts. If
@@ -1187,7 +1187,7 @@ static int posix_lock_inode(struct inode
 	}
  out:
 	spin_unlock(&ctx->flc_lock);
-	percpu_up_read_preempt_enable(&file_rwsem);
+	percpu_up_read(&file_rwsem);
 	/*
 	 * Free any unused locks.
 	 */
@@ -1462,7 +1462,7 @@ int __break_lease(struct inode *inode, u
 		return error;
 	}
 
-	percpu_down_read_preempt_disable(&file_rwsem);
+	percpu_down_read(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 
 	time_out_leases(inode, &dispose);
@@ -1514,13 +1514,13 @@ restart:
 	locks_insert_block(fl, new_fl);
 	trace_break_lease_block(inode, new_fl);
 	spin_unlock(&ctx->flc_lock);
-	percpu_up_read_preempt_enable(&file_rwsem);
+	percpu_up_read(&file_rwsem);
 
 	locks_dispose_list(&dispose);
 	error = wait_event_interruptible_timeout(new_fl->fl_wait,
 						!new_fl->fl_next, break_time);
 
-	percpu_down_read_preempt_disable(&file_rwsem);
+	percpu_down_read(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	trace_break_lease_unblock(inode, new_fl);
 	locks_delete_block(new_fl);
@@ -1537,7 +1537,7 @@ restart:
 	}
 out:
 	spin_unlock(&ctx->flc_lock);
-	percpu_up_read_preempt_enable(&file_rwsem);
+	percpu_up_read(&file_rwsem);
 	locks_dispose_list(&dispose);
 	locks_free_lock(new_fl);
 	return error;
@@ -1609,7 +1609,7 @@ int fcntl_getlease(struct file *filp)
 
 	ctx = smp_load_acquire(&inode->i_flctx);
 	if (ctx && !list_empty_careful(&ctx->flc_lease)) {
-		percpu_down_read_preempt_disable(&file_rwsem);
+		percpu_down_read(&file_rwsem);
 		spin_lock(&ctx->flc_lock);
 		time_out_leases(inode, &dispose);
 		list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
@@ -1619,7 +1619,7 @@ int fcntl_getlease(struct file *filp)
 			break;
 		}
 		spin_unlock(&ctx->flc_lock);
-		percpu_up_read_preempt_enable(&file_rwsem);
+		percpu_up_read(&file_rwsem);
 
 		locks_dispose_list(&dispose);
 	}
@@ -1693,7 +1693,7 @@ generic_add_lease(struct file *filp, lon
 		return -EINVAL;
 	}
 
-	percpu_down_read_preempt_disable(&file_rwsem);
+	percpu_down_read(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	time_out_leases(inode, &dispose);
 	error = check_conflicting_open(dentry, arg, lease->fl_flags);
@@ -1764,7 +1764,7 @@ out_setup:
 		lease->fl_lmops->lm_setup(lease, priv);
 out:
 	spin_unlock(&ctx->flc_lock);
-	percpu_up_read_preempt_enable(&file_rwsem);
+	percpu_up_read(&file_rwsem);
 	locks_dispose_list(&dispose);
 	if (is_deleg)
 		inode_unlock(inode);
@@ -1787,7 +1787,7 @@ static int generic_delete_lease(struct f
 		return error;
 	}
 
-	percpu_down_read_preempt_disable(&file_rwsem);
+	percpu_down_read(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
 		if (fl->fl_file == filp &&
@@ -1800,7 +1800,7 @@ static int generic_delete_lease(struct f
 	if (victim)
 		error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose);
 	spin_unlock(&ctx->flc_lock);
-	percpu_up_read_preempt_enable(&file_rwsem);
+	percpu_up_read(&file_rwsem);
 	locks_dispose_list(&dispose);
 	return error;
 }
@@ -2531,13 +2531,13 @@ locks_remove_lease(struct file *filp, st
 	if (list_empty(&ctx->flc_lease))
 		return;
 
-	percpu_down_read_preempt_disable(&file_rwsem);
+	percpu_down_read(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
 		if (filp == fl->fl_file)
 			lease_modify(fl, F_UNLCK, &dispose);
 	spin_unlock(&ctx->flc_lock);
-	percpu_up_read_preempt_enable(&file_rwsem);
+	percpu_up_read(&file_rwsem);
 
 	locks_dispose_list(&dispose);
 }
Index: linux-4.19.25-rt16/fs/namei.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/namei.c
+++ linux-4.19.25-rt16/fs/namei.c
@@ -1645,7 +1645,7 @@ static struct dentry *__lookup_slow(cons
 {
 	struct dentry *dentry, *old;
 	struct inode *inode = dir->d_inode;
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	/* Don't go there if it's already dead */
 	if (unlikely(IS_DEADDIR(inode)))
@@ -3135,7 +3135,7 @@ static int lookup_open(struct nameidata
 	struct dentry *dentry;
 	int error, create_error = 0;
 	umode_t mode = op->mode;
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 
 	if (unlikely(IS_DEADDIR(dir_inode)))
 		return -ENOENT;
Index: linux-4.19.25-rt16/fs/namespace.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/namespace.c
+++ linux-4.19.25-rt16/fs/namespace.c
@@ -14,6 +14,7 @@
 #include <linux/mnt_namespace.h>
 #include <linux/user_namespace.h>
 #include <linux/namei.h>
+#include <linux/delay.h>
 #include <linux/security.h>
 #include <linux/cred.h>
 #include <linux/idr.h>
@@ -327,8 +328,11 @@ int __mnt_want_write(struct vfsmount *m)
 	 * incremented count after it has set MNT_WRITE_HOLD.
 	 */
 	smp_mb();
-	while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD)
-		cpu_relax();
+	while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) {
+		preempt_enable();
+		cpu_chill();
+		preempt_disable();
+	}
 	/*
 	 * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
 	 * be set to match its requirements. So we must not load that until
Index: linux-4.19.25-rt16/fs/nfs/delegation.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/nfs/delegation.c
+++ linux-4.19.25-rt16/fs/nfs/delegation.c
@@ -152,11 +152,11 @@ again:
 		sp = state->owner;
 		/* Block nfs4_proc_unlck */
 		mutex_lock(&sp->so_delegreturn_mutex);
-		seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
+		seq = read_seqbegin(&sp->so_reclaim_seqlock);
 		err = nfs4_open_delegation_recall(ctx, state, stateid, type);
 		if (!err)
 			err = nfs_delegation_claim_locks(ctx, state, stateid);
-		if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
+		if (!err && read_seqretry(&sp->so_reclaim_seqlock, seq))
 			err = -EAGAIN;
 		mutex_unlock(&sp->so_delegreturn_mutex);
 		put_nfs_open_context(ctx);
Index: linux-4.19.25-rt16/fs/nfs/dir.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/nfs/dir.c
+++ linux-4.19.25-rt16/fs/nfs/dir.c
@@ -445,7 +445,7 @@ static
 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
 {
 	struct qstr filename = QSTR_INIT(entry->name, entry->len);
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 	struct dentry *dentry;
 	struct dentry *alias;
 	struct inode *dir = d_inode(parent);
@@ -1459,7 +1459,7 @@ int nfs_atomic_open(struct inode *dir, s
 		    struct file *file, unsigned open_flags,
 		    umode_t mode)
 {
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 	struct nfs_open_context *ctx;
 	struct dentry *res;
 	struct iattr attr = { .ia_valid = ATTR_OPEN };
@@ -1786,7 +1786,11 @@ int nfs_rmdir(struct inode *dir, struct
 
 	trace_nfs_rmdir_enter(dir, dentry);
 	if (d_really_is_positive(dentry)) {
+#ifdef CONFIG_PREEMPT_RT_BASE
+		down(&NFS_I(d_inode(dentry))->rmdir_sem);
+#else
 		down_write(&NFS_I(d_inode(dentry))->rmdir_sem);
+#endif
 		error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
 		/* Ensure the VFS deletes this inode */
 		switch (error) {
@@ -1796,7 +1800,11 @@ int nfs_rmdir(struct inode *dir, struct
 		case -ENOENT:
 			nfs_dentry_handle_enoent(dentry);
 		}
+#ifdef CONFIG_PREEMPT_RT_BASE
+		up(&NFS_I(d_inode(dentry))->rmdir_sem);
+#else
 		up_write(&NFS_I(d_inode(dentry))->rmdir_sem);
+#endif
 	} else
 		error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
 	trace_nfs_rmdir_exit(dir, dentry, error);
Index: linux-4.19.25-rt16/fs/nfs/inode.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/nfs/inode.c
+++ linux-4.19.25-rt16/fs/nfs/inode.c
@@ -2103,7 +2103,11 @@ static void init_once(void *foo)
 	atomic_long_set(&nfsi->nrequests, 0);
 	atomic_long_set(&nfsi->commit_info.ncommit, 0);
 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
+#ifdef CONFIG_PREEMPT_RT_BASE
+	sema_init(&nfsi->rmdir_sem, 1);
+#else
 	init_rwsem(&nfsi->rmdir_sem);
+#endif
 	mutex_init(&nfsi->commit_mutex);
 	nfs4_init_once(nfsi);
 }
Index: linux-4.19.25-rt16/fs/nfs/nfs4_fs.h
===================================================================
--- linux-4.19.25-rt16.orig/fs/nfs/nfs4_fs.h
+++ linux-4.19.25-rt16/fs/nfs/nfs4_fs.h
@@ -114,7 +114,7 @@ struct nfs4_state_owner {
 	unsigned long	     so_flags;
 	struct list_head     so_states;
 	struct nfs_seqid_counter so_seqid;
-	seqcount_t	     so_reclaim_seqcount;
+	seqlock_t	     so_reclaim_seqlock;
 	struct mutex	     so_delegreturn_mutex;
 };
 
Index: linux-4.19.25-rt16/fs/nfs/nfs4proc.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/nfs/nfs4proc.c
+++ linux-4.19.25-rt16/fs/nfs/nfs4proc.c
@@ -2863,7 +2863,7 @@ static int _nfs4_open_and_get_state(stru
 	unsigned int seq;
 	int ret;
 
-	seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
+	seq = raw_seqcount_begin(&sp->so_reclaim_seqlock.seqcount);
 
 	ret = _nfs4_proc_open(opendata, ctx);
 	if (ret != 0)
@@ -2904,7 +2904,7 @@ static int _nfs4_open_and_get_state(stru
 
 	if (d_inode(dentry) == state->inode) {
 		nfs_inode_attach_open_context(ctx);
-		if (read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
+		if (read_seqretry(&sp->so_reclaim_seqlock, seq))
 			nfs4_schedule_stateid_recovery(server, state);
 	}
 
Index: linux-4.19.25-rt16/fs/nfs/nfs4state.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/nfs/nfs4state.c
+++ linux-4.19.25-rt16/fs/nfs/nfs4state.c
@@ -511,7 +511,7 @@ nfs4_alloc_state_owner(struct nfs_server
 	nfs4_init_seqid_counter(&sp->so_seqid);
 	atomic_set(&sp->so_count, 1);
 	INIT_LIST_HEAD(&sp->so_lru);
-	seqcount_init(&sp->so_reclaim_seqcount);
+	seqlock_init(&sp->so_reclaim_seqlock);
 	mutex_init(&sp->so_delegreturn_mutex);
 	return sp;
 }
@@ -1564,8 +1564,12 @@ static int nfs4_reclaim_open_state(struc
 	 * recovering after a network partition or a reboot from a
 	 * server that doesn't support a grace period.
 	 */
+#ifdef CONFIG_PREEMPT_RT_FULL
+	write_seqlock(&sp->so_reclaim_seqlock);
+#else
+	write_seqcount_begin(&sp->so_reclaim_seqlock.seqcount);
+#endif
 	spin_lock(&sp->so_lock);
-	raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
 restart:
 	list_for_each_entry(state, &sp->so_states, open_states) {
 		if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
@@ -1652,14 +1656,20 @@ restart:
 		spin_lock(&sp->so_lock);
 		goto restart;
 	}
-	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
 	spin_unlock(&sp->so_lock);
+#ifdef CONFIG_PREEMPT_RT_FULL
+	write_sequnlock(&sp->so_reclaim_seqlock);
+#else
+	write_seqcount_end(&sp->so_reclaim_seqlock.seqcount);
+#endif
 	return 0;
 out_err:
 	nfs4_put_open_state(state);
-	spin_lock(&sp->so_lock);
-	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
-	spin_unlock(&sp->so_lock);
+#ifdef CONFIG_PREEMPT_RT_FULL
+	write_sequnlock(&sp->so_reclaim_seqlock);
+#else
+	write_seqcount_end(&sp->so_reclaim_seqlock.seqcount);
+#endif
 	return status;
 }
 
Index: linux-4.19.25-rt16/fs/nfs/unlink.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/nfs/unlink.c
+++ linux-4.19.25-rt16/fs/nfs/unlink.c
@@ -13,7 +13,7 @@
 #include <linux/sunrpc/clnt.h>
 #include <linux/nfs_fs.h>
 #include <linux/sched.h>
-#include <linux/wait.h>
+#include <linux/swait.h>
 #include <linux/namei.h>
 #include <linux/fsnotify.h>
 
@@ -52,6 +52,29 @@ static void nfs_async_unlink_done(struct
 		rpc_restart_call_prepare(task);
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+static void nfs_down_anon(struct semaphore *sema)
+{
+	down(sema);
+}
+
+static void nfs_up_anon(struct semaphore *sema)
+{
+	up(sema);
+}
+
+#else
+static void nfs_down_anon(struct rw_semaphore *rwsem)
+{
+	down_read_non_owner(rwsem);
+}
+
+static void nfs_up_anon(struct rw_semaphore *rwsem)
+{
+	up_read_non_owner(rwsem);
+}
+#endif
+
 /**
  * nfs_async_unlink_release - Release the sillydelete data.
  * @task: rpc_task of the sillydelete
@@ -65,7 +88,7 @@ static void nfs_async_unlink_release(voi
 	struct dentry *dentry = data->dentry;
 	struct super_block *sb = dentry->d_sb;
 
-	up_read_non_owner(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem);
+	nfs_up_anon(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem);
 	d_lookup_done(dentry);
 	nfs_free_unlinkdata(data);
 	dput(dentry);
@@ -118,10 +141,10 @@ static int nfs_call_unlink(struct dentry
 	struct inode *dir = d_inode(dentry->d_parent);
 	struct dentry *alias;
 
-	down_read_non_owner(&NFS_I(dir)->rmdir_sem);
+	nfs_down_anon(&NFS_I(dir)->rmdir_sem);
 	alias = d_alloc_parallel(dentry->d_parent, &data->args.name, &data->wq);
 	if (IS_ERR(alias)) {
-		up_read_non_owner(&NFS_I(dir)->rmdir_sem);
+		nfs_up_anon(&NFS_I(dir)->rmdir_sem);
 		return 0;
 	}
 	if (!d_in_lookup(alias)) {
@@ -143,7 +166,7 @@ static int nfs_call_unlink(struct dentry
 			ret = 0;
 		spin_unlock(&alias->d_lock);
 		dput(alias);
-		up_read_non_owner(&NFS_I(dir)->rmdir_sem);
+		nfs_up_anon(&NFS_I(dir)->rmdir_sem);
 		/*
 		 * If we'd displaced old cached devname, free it.  At that
 		 * point dentry is definitely not a root, so we won't need
@@ -183,7 +206,7 @@ nfs_async_unlink(struct dentry *dentry,
 		goto out_free_name;
 	}
 	data->res.dir_attr = &data->dir_attr;
-	init_waitqueue_head(&data->wq);
+	init_swait_queue_head(&data->wq);
 
 	status = -EBUSY;
 	spin_lock(&dentry->d_lock);
Index: linux-4.19.25-rt16/fs/ntfs/aops.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/ntfs/aops.c
+++ linux-4.19.25-rt16/fs/ntfs/aops.c
@@ -106,8 +106,7 @@ static void ntfs_end_buffer_async_read(s
 				"0x%llx.", (unsigned long long)bh->b_blocknr);
 	}
 	first = page_buffers(page);
-	local_irq_save(flags);
-	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+	flags = bh_uptodate_lock_irqsave(first);
 	clear_buffer_async_read(bh);
 	unlock_buffer(bh);
 	tmp = bh;
@@ -122,8 +121,7 @@ static void ntfs_end_buffer_async_read(s
 		}
 		tmp = tmp->b_this_page;
 	} while (tmp != bh);
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
+	bh_uptodate_unlock_irqrestore(first, flags);
 	/*
 	 * If none of the buffers had errors then we can set the page uptodate,
 	 * but we first have to perform the post read mst fixups, if the
@@ -156,9 +154,7 @@ static void ntfs_end_buffer_async_read(s
 	unlock_page(page);
 	return;
 still_busy:
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	return;
+	bh_uptodate_unlock_irqrestore(first, flags);
 }
 
 /**
Index: linux-4.19.25-rt16/fs/proc/array.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/proc/array.c
+++ linux-4.19.25-rt16/fs/proc/array.c
@@ -381,9 +381,9 @@ static inline void task_context_switch_c
 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
 {
 	seq_printf(m, "Cpus_allowed:\t%*pb\n",
-		   cpumask_pr_args(&task->cpus_allowed));
+		   cpumask_pr_args(task->cpus_ptr));
 	seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
-		   cpumask_pr_args(&task->cpus_allowed));
+		   cpumask_pr_args(task->cpus_ptr));
 }
 
 static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm)
Index: linux-4.19.25-rt16/fs/proc/base.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/proc/base.c
+++ linux-4.19.25-rt16/fs/proc/base.c
@@ -1872,7 +1872,7 @@ bool proc_fill_cache(struct file *file,
 
 	child = d_hash_and_lookup(dir, &qname);
 	if (!child) {
-		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+		DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 		child = d_alloc_parallel(dir, &qname, &wq);
 		if (IS_ERR(child))
 			goto end_instantiate;
Index: linux-4.19.25-rt16/fs/proc/proc_sysctl.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/proc/proc_sysctl.c
+++ linux-4.19.25-rt16/fs/proc/proc_sysctl.c
@@ -677,7 +677,7 @@ static bool proc_sys_fill_cache(struct f
 
 	child = d_lookup(dir, &qname);
 	if (!child) {
-		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+		DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq);
 		child = d_alloc_parallel(dir, &qname, &wq);
 		if (IS_ERR(child))
 			return false;
Index: linux-4.19.25-rt16/fs/squashfs/decompressor_multi_percpu.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/squashfs/decompressor_multi_percpu.c
+++ linux-4.19.25-rt16/fs/squashfs/decompressor_multi_percpu.c
@@ -10,6 +10,7 @@
 #include <linux/slab.h>
 #include <linux/percpu.h>
 #include <linux/buffer_head.h>
+#include <linux/locallock.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
@@ -25,6 +26,8 @@ struct squashfs_stream {
 	void		*stream;
 };
 
+static DEFINE_LOCAL_IRQ_LOCK(stream_lock);
+
 void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
 						void *comp_opts)
 {
@@ -79,10 +82,15 @@ int squashfs_decompress(struct squashfs_
 {
 	struct squashfs_stream __percpu *percpu =
 			(struct squashfs_stream __percpu *) msblk->stream;
-	struct squashfs_stream *stream = get_cpu_ptr(percpu);
-	int res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
-		offset, length, output);
-	put_cpu_ptr(stream);
+	struct squashfs_stream *stream;
+	int res;
+
+	stream = get_locked_ptr(stream_lock, percpu);
+
+	res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
+			offset, length, output);
+
+	put_locked_ptr(stream_lock, stream);
 
 	if (res < 0)
 		ERROR("%s decompression failed, data probably corrupt\n",
Index: linux-4.19.25-rt16/fs/timerfd.c
===================================================================
--- linux-4.19.25-rt16.orig/fs/timerfd.c
+++ linux-4.19.25-rt16/fs/timerfd.c
@@ -471,7 +471,10 @@ static int do_timerfd_settime(int ufd, i
 				break;
 		}
 		spin_unlock_irq(&ctx->wqh.lock);
-		cpu_relax();
+		if (isalarm(ctx))
+			hrtimer_wait_for_timer(&ctx->t.alarm.timer);
+		else
+			hrtimer_wait_for_timer(&ctx->t.tmr);
 	}
 
 	/*
Index: linux-4.19.25-rt16/include/asm-generic/percpu.h
===================================================================
--- linux-4.19.25-rt16.orig/include/asm-generic/percpu.h
+++ linux-4.19.25-rt16/include/asm-generic/percpu.h
@@ -5,6 +5,7 @@
 #include <linux/compiler.h>
 #include <linux/threads.h>
 #include <linux/percpu-defs.h>
+#include <linux/irqflags.h>
 
 #ifdef CONFIG_SMP
 
Index: linux-4.19.25-rt16/include/linux/blk-mq.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/blk-mq.h
+++ linux-4.19.25-rt16/include/linux/blk-mq.h
@@ -249,7 +249,7 @@ static inline u16 blk_mq_unique_tag_to_t
 	return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
 }
 
-
+void __blk_mq_complete_request_remote_work(struct work_struct *work);
 int blk_mq_request_started(struct request *rq);
 void blk_mq_start_request(struct request *rq);
 void blk_mq_end_request(struct request *rq, blk_status_t error);
Index: linux-4.19.25-rt16/include/linux/blkdev.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/blkdev.h
+++ linux-4.19.25-rt16/include/linux/blkdev.h
@@ -27,6 +27,7 @@
 #include <linux/percpu-refcount.h>
 #include <linux/scatterlist.h>
 #include <linux/blkzoned.h>
+#include <linux/swork.h>
 
 struct module;
 struct scsi_ioctl_command;
@@ -149,6 +150,9 @@ enum mq_rq_state {
  */
 struct request {
 	struct request_queue *q;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	struct work_struct work;
+#endif
 	struct blk_mq_ctx *mq_ctx;
 
 	int cpu;
@@ -646,6 +650,7 @@ struct request_queue {
 #endif
 	struct rcu_head		rcu_head;
 	wait_queue_head_t	mq_freeze_wq;
+	struct swork_event	mq_pcpu_wake;
 	struct percpu_ref	q_usage_counter;
 	struct list_head	all_q_node;
 
Index: linux-4.19.25-rt16/include/linux/bottom_half.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/bottom_half.h
+++ linux-4.19.25-rt16/include/linux/bottom_half.h
@@ -4,6 +4,39 @@
 
 #include <linux/preempt.h>
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+
+extern void __local_bh_disable(void);
+extern void _local_bh_enable(void);
+extern void __local_bh_enable(void);
+
+static inline void local_bh_disable(void)
+{
+	__local_bh_disable();
+}
+
+static inline void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
+{
+	__local_bh_disable();
+}
+
+static inline void local_bh_enable(void)
+{
+	__local_bh_enable();
+}
+
+static inline void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
+{
+	__local_bh_enable();
+}
+
+static inline void local_bh_enable_ip(unsigned long ip)
+{
+	__local_bh_enable();
+}
+
+#else
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);
 #else
@@ -31,5 +64,6 @@ static inline void local_bh_enable(void)
 {
 	__local_bh_enable_ip(_THIS_IP_, SOFTIRQ_DISABLE_OFFSET);
 }
+#endif
 
 #endif /* _LINUX_BH_H */
Index: linux-4.19.25-rt16/include/linux/buffer_head.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/buffer_head.h
+++ linux-4.19.25-rt16/include/linux/buffer_head.h
@@ -76,8 +76,50 @@ struct buffer_head {
 	struct address_space *b_assoc_map;	/* mapping this buffer is
 						   associated with */
 	atomic_t b_count;		/* users using this buffer_head */
+#ifdef CONFIG_PREEMPT_RT_BASE
+	spinlock_t b_uptodate_lock;
+#if IS_ENABLED(CONFIG_JBD2)
+	spinlock_t b_state_lock;
+	spinlock_t b_journal_head_lock;
+#endif
+#endif
 };
 
+static inline unsigned long bh_uptodate_lock_irqsave(struct buffer_head *bh)
+{
+	unsigned long flags;
+
+#ifndef CONFIG_PREEMPT_RT_BASE
+	local_irq_save(flags);
+	bit_spin_lock(BH_Uptodate_Lock, &bh->b_state);
+#else
+	spin_lock_irqsave(&bh->b_uptodate_lock, flags);
+#endif
+	return flags;
+}
+
+static inline void
+bh_uptodate_unlock_irqrestore(struct buffer_head *bh, unsigned long flags)
+{
+#ifndef CONFIG_PREEMPT_RT_BASE
+	bit_spin_unlock(BH_Uptodate_Lock, &bh->b_state);
+	local_irq_restore(flags);
+#else
+	spin_unlock_irqrestore(&bh->b_uptodate_lock, flags);
+#endif
+}
+
+static inline void buffer_head_init_locks(struct buffer_head *bh)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+	spin_lock_init(&bh->b_uptodate_lock);
+#if IS_ENABLED(CONFIG_JBD2)
+	spin_lock_init(&bh->b_state_lock);
+	spin_lock_init(&bh->b_journal_head_lock);
+#endif
+#endif
+}
+
 /*
  * macro tricks to expand the set_buffer_foo(), clear_buffer_foo()
  * and buffer_foo() functions.
Index: linux-4.19.25-rt16/include/linux/cgroup-defs.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/cgroup-defs.h
+++ linux-4.19.25-rt16/include/linux/cgroup-defs.h
@@ -20,6 +20,7 @@
 #include <linux/u64_stats_sync.h>
 #include <linux/workqueue.h>
 #include <linux/bpf-cgroup.h>
+#include <linux/swork.h>
 
 #ifdef CONFIG_CGROUPS
 
@@ -157,6 +158,7 @@ struct cgroup_subsys_state {
 
 	/* percpu_ref killing and RCU release */
 	struct work_struct destroy_work;
+	struct swork_event destroy_swork;
 	struct rcu_work destroy_rwork;
 
 	/*
Index: linux-4.19.25-rt16/include/linux/completion.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/completion.h
+++ linux-4.19.25-rt16/include/linux/completion.h
@@ -9,7 +9,7 @@
  * See kernel/sched/completion.c for details.
  */
 
-#include <linux/wait.h>
+#include <linux/swait.h>
 
 /*
  * struct completion - structure used to maintain state for a "completion"
@@ -25,7 +25,7 @@
  */
 struct completion {
 	unsigned int done;
-	wait_queue_head_t wait;
+	struct swait_queue_head wait;
 };
 
 #define init_completion_map(x, m) __init_completion(x)
@@ -34,7 +34,7 @@ static inline void complete_acquire(stru
 static inline void complete_release(struct completion *x) {}
 
 #define COMPLETION_INITIALIZER(work) \
-	{ 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+	{ 0, __SWAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
 
 #define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \
 	(*({ init_completion_map(&(work), &(map)); &(work); }))
@@ -85,7 +85,7 @@ static inline void complete_release(stru
 static inline void __init_completion(struct completion *x)
 {
 	x->done = 0;
-	init_waitqueue_head(&x->wait);
+	init_swait_queue_head(&x->wait);
 }
 
 /**
Index: linux-4.19.25-rt16/include/linux/cpu.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/cpu.h
+++ linux-4.19.25-rt16/include/linux/cpu.h
@@ -111,6 +111,8 @@ extern void cpu_hotplug_disable(void);
 extern void cpu_hotplug_enable(void);
 void clear_tasks_mm_cpumask(int cpu);
 int cpu_down(unsigned int cpu);
+extern void pin_current_cpu(void);
+extern void unpin_current_cpu(void);
 
 #else /* CONFIG_HOTPLUG_CPU */
 
@@ -122,6 +124,9 @@ static inline int  cpus_read_trylock(voi
 static inline void lockdep_assert_cpus_held(void) { }
 static inline void cpu_hotplug_disable(void) { }
 static inline void cpu_hotplug_enable(void) { }
+static inline void pin_current_cpu(void) { }
+static inline void unpin_current_cpu(void) { }
+
 #endif	/* !CONFIG_HOTPLUG_CPU */
 
 /* Wrappers which go away once all code is converted */
Index: linux-4.19.25-rt16/include/linux/dcache.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/dcache.h
+++ linux-4.19.25-rt16/include/linux/dcache.h
@@ -105,7 +105,7 @@ struct dentry {
 
 	union {
 		struct list_head d_lru;		/* LRU list */
-		wait_queue_head_t *d_wait;	/* in-lookup ones only */
+		struct swait_queue_head *d_wait;	/* in-lookup ones only */
 	};
 	struct list_head d_child;	/* child of parent list */
 	struct list_head d_subdirs;	/* our children */
@@ -236,7 +236,7 @@ extern struct dentry * d_alloc(struct de
 extern struct dentry * d_alloc_anon(struct super_block *);
 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
 extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *,
-					wait_queue_head_t *);
+					struct swait_queue_head *);
 extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
 extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
 extern struct dentry * d_exact_alias(struct dentry *, struct inode *);
Index: linux-4.19.25-rt16/include/linux/delay.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/delay.h
+++ linux-4.19.25-rt16/include/linux/delay.h
@@ -64,4 +64,10 @@ static inline void ssleep(unsigned int s
 	msleep(seconds * 1000);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void cpu_chill(void);
+#else
+# define cpu_chill()	cpu_relax()
+#endif
+
 #endif /* defined(_LINUX_DELAY_H) */
Index: linux-4.19.25-rt16/include/linux/fs.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/fs.h
+++ linux-4.19.25-rt16/include/linux/fs.h
@@ -669,7 +669,7 @@ struct inode {
 		struct block_device	*i_bdev;
 		struct cdev		*i_cdev;
 		char			*i_link;
-		unsigned		i_dir_seq;
+		unsigned		__i_dir_seq;
 	};
 
 	__u32			i_generation;
Index: linux-4.19.25-rt16/include/linux/fscache.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/fscache.h
+++ linux-4.19.25-rt16/include/linux/fscache.h
@@ -230,6 +230,7 @@ extern void __fscache_readpages_cancel(s
 extern void __fscache_disable_cookie(struct fscache_cookie *, const void *, bool);
 extern void __fscache_enable_cookie(struct fscache_cookie *, const void *, loff_t,
 				    bool (*)(void *), void *);
+extern void fscache_cookie_init(void);
 
 /**
  * fscache_register_netfs - Register a filesystem as desiring caching services
Index: linux-4.19.25-rt16/include/linux/highmem.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/highmem.h
+++ linux-4.19.25-rt16/include/linux/highmem.h
@@ -8,6 +8,7 @@
 #include <linux/mm.h>
 #include <linux/uaccess.h>
 #include <linux/hardirq.h>
+#include <linux/sched.h>
 
 #include <asm/cacheflush.h>
 
@@ -66,7 +67,7 @@ static inline void kunmap(struct page *p
 
 static inline void *kmap_atomic(struct page *page)
 {
-	preempt_disable();
+	preempt_disable_nort();
 	pagefault_disable();
 	return page_address(page);
 }
@@ -75,7 +76,7 @@ static inline void *kmap_atomic(struct p
 static inline void __kunmap_atomic(void *addr)
 {
 	pagefault_enable();
-	preempt_enable();
+	preempt_enable_nort();
 }
 
 #define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
@@ -87,32 +88,51 @@ static inline void __kunmap_atomic(void
 
 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 DECLARE_PER_CPU(int, __kmap_atomic_idx);
+#endif
 
 static inline int kmap_atomic_idx_push(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
 
-#ifdef CONFIG_DEBUG_HIGHMEM
+# ifdef CONFIG_DEBUG_HIGHMEM
 	WARN_ON_ONCE(in_irq() && !irqs_disabled());
 	BUG_ON(idx >= KM_TYPE_NR);
-#endif
+# endif
 	return idx;
+#else
+	current->kmap_idx++;
+	BUG_ON(current->kmap_idx > KM_TYPE_NR);
+	return current->kmap_idx - 1;
+#endif
 }
 
 static inline int kmap_atomic_idx(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	return __this_cpu_read(__kmap_atomic_idx) - 1;
+#else
+	return current->kmap_idx - 1;
+#endif
 }
 
 static inline void kmap_atomic_idx_pop(void)
 {
-#ifdef CONFIG_DEBUG_HIGHMEM
+#ifndef CONFIG_PREEMPT_RT_FULL
+# ifdef CONFIG_DEBUG_HIGHMEM
 	int idx = __this_cpu_dec_return(__kmap_atomic_idx);
 
 	BUG_ON(idx < 0);
-#else
+# else
 	__this_cpu_dec(__kmap_atomic_idx);
+# endif
+#else
+	current->kmap_idx--;
+# ifdef CONFIG_DEBUG_HIGHMEM
+	BUG_ON(current->kmap_idx < 0);
+# endif
 #endif
 }
 
Index: linux-4.19.25-rt16/include/linux/hrtimer.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/hrtimer.h
+++ linux-4.19.25-rt16/include/linux/hrtimer.h
@@ -22,6 +22,7 @@
 #include <linux/percpu.h>
 #include <linux/timer.h>
 #include <linux/timerqueue.h>
+#include <linux/wait.h>
 
 struct hrtimer_clock_base;
 struct hrtimer_cpu_base;
@@ -41,6 +42,7 @@ enum hrtimer_mode {
 	HRTIMER_MODE_REL	= 0x01,
 	HRTIMER_MODE_PINNED	= 0x02,
 	HRTIMER_MODE_SOFT	= 0x04,
+	HRTIMER_MODE_HARD	= 0x08,
 
 	HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED,
 	HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED,
@@ -51,6 +53,11 @@ enum hrtimer_mode {
 	HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT,
 	HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT,
 
+	HRTIMER_MODE_ABS_HARD	= HRTIMER_MODE_ABS | HRTIMER_MODE_HARD,
+	HRTIMER_MODE_REL_HARD	= HRTIMER_MODE_REL | HRTIMER_MODE_HARD,
+
+	HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_HARD,
+	HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD,
 };
 
 /*
@@ -216,6 +223,9 @@ struct hrtimer_cpu_base {
 	ktime_t				expires_next;
 	struct hrtimer			*next_timer;
 	ktime_t				softirq_expires_next;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	wait_queue_head_t		wait;
+#endif
 	struct hrtimer			*softirq_next_timer;
 	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
 } ____cacheline_aligned;
@@ -364,10 +374,17 @@ DECLARE_PER_CPU(struct tick_device, tick
 /* Initialize timers: */
 extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
 			 enum hrtimer_mode mode);
+extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
+				 enum hrtimer_mode mode,
+				 struct task_struct *task);
 
 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
 				  enum hrtimer_mode mode);
+extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+					  clockid_t clock_id,
+					  enum hrtimer_mode mode,
+					  struct task_struct *task);
 
 extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
 #else
@@ -377,6 +394,15 @@ static inline void hrtimer_init_on_stack
 {
 	hrtimer_init(timer, which_clock, mode);
 }
+
+static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+					    clockid_t clock_id,
+					    enum hrtimer_mode mode,
+					    struct task_struct *task)
+{
+	hrtimer_init_sleeper(sl, clock_id, mode, task);
+}
+
 static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
 #endif
 
@@ -417,6 +443,13 @@ static inline void hrtimer_restart(struc
 	hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
+/* Softirq preemption could deadlock timer removal */
+#ifdef CONFIG_PREEMPT_RT_BASE
+  extern void hrtimer_wait_for_timer(const struct hrtimer *timer);
+#else
+# define hrtimer_wait_for_timer(timer)	do { cpu_relax(); } while (0)
+#endif
+
 /* Query timers: */
 extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);
 
@@ -442,7 +475,7 @@ static inline int hrtimer_is_queued(stru
  * Helper function to check, whether the timer is running the callback
  * function
  */
-static inline int hrtimer_callback_running(struct hrtimer *timer)
+static inline int hrtimer_callback_running(const struct hrtimer *timer)
 {
 	return timer->base->running == timer;
 }
@@ -480,9 +513,6 @@ extern long hrtimer_nanosleep(const stru
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);
 
-extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
-				 struct task_struct *tsk);
-
 extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
 						const enum hrtimer_mode mode);
 extern int schedule_hrtimeout_range_clock(ktime_t *expires,
Index: linux-4.19.25-rt16/include/linux/idr.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/idr.h
+++ linux-4.19.25-rt16/include/linux/idr.h
@@ -169,10 +169,7 @@ static inline bool idr_is_empty(const st
  * Each idr_preload() should be matched with an invocation of this
  * function.  See idr_preload() for details.
  */
-static inline void idr_preload_end(void)
-{
-	preempt_enable();
-}
+void idr_preload_end(void);
 
 /**
  * idr_for_each_entry() - Iterate over an IDR's elements of a given type.
Index: linux-4.19.25-rt16/include/linux/interrupt.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/interrupt.h
+++ linux-4.19.25-rt16/include/linux/interrupt.h
@@ -13,6 +13,7 @@
 #include <linux/hrtimer.h>
 #include <linux/kref.h>
 #include <linux/workqueue.h>
+#include <linux/swork.h>
 
 #include <linux/atomic.h>
 #include <asm/ptrace.h>
@@ -61,6 +62,7 @@
  *                interrupt handler after suspending interrupts. For system
  *                wakeup devices users need to implement wakeup detection in
  *                their interrupt handlers.
+ * IRQF_NO_SOFTIRQ_CALL - Do not process softirqs in the irq thread context (RT)
  */
 #define IRQF_SHARED		0x00000080
 #define IRQF_PROBE_SHARED	0x00000100
@@ -74,6 +76,7 @@
 #define IRQF_NO_THREAD		0x00010000
 #define IRQF_EARLY_RESUME	0x00020000
 #define IRQF_COND_SUSPEND	0x00040000
+#define IRQF_NO_SOFTIRQ_CALL	0x00080000
 
 #define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
 
@@ -225,6 +228,7 @@ extern void resume_device_irqs(void);
  * struct irq_affinity_notify - context for notification of IRQ affinity changes
  * @irq:		Interrupt to which notification applies
  * @kref:		Reference count, for internal use
+ * @swork:		Swork item, for internal use
  * @work:		Work item, for internal use
  * @notify:		Function to be called on change.  This will be
  *			called in process context.
@@ -236,7 +240,11 @@ extern void resume_device_irqs(void);
 struct irq_affinity_notify {
 	unsigned int irq;
 	struct kref kref;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	struct swork_event swork;
+#else
 	struct work_struct work;
+#endif
 	void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
 	void (*release)(struct kref *ref);
 };
@@ -427,7 +435,11 @@ extern int irq_set_irqchip_state(unsigne
 				 bool state);
 
 #ifdef CONFIG_IRQ_FORCED_THREADING
+# ifdef CONFIG_PREEMPT_RT_BASE
+#  define force_irqthreads	(true)
+# else
 extern bool force_irqthreads;
+# endif
 #else
 #define force_irqthreads	(0)
 #endif
@@ -493,9 +505,10 @@ struct softirq_action
 	void	(*action)(struct softirq_action *);
 };
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 asmlinkage void do_softirq(void);
 asmlinkage void __do_softirq(void);
-
+static inline void thread_do_softirq(void) { do_softirq(); }
 #ifdef __ARCH_HAS_DO_SOFTIRQ
 void do_softirq_own_stack(void);
 #else
@@ -504,13 +517,25 @@ static inline void do_softirq_own_stack(
 	__do_softirq();
 }
 #endif
+#else
+extern void thread_do_softirq(void);
+#endif
 
 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 extern void softirq_init(void);
 extern void __raise_softirq_irqoff(unsigned int nr);
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void __raise_softirq_irqoff_ksoft(unsigned int nr);
+#else
+static inline void __raise_softirq_irqoff_ksoft(unsigned int nr)
+{
+	__raise_softirq_irqoff(nr);
+}
+#endif
 
 extern void raise_softirq_irqoff(unsigned int nr);
 extern void raise_softirq(unsigned int nr);
+extern void softirq_check_pending_idle(void);
 
 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
 
@@ -532,8 +557,9 @@ static inline struct task_struct *this_c
      to be executed on some cpu at least once after this.
    * If the tasklet is already scheduled, but its execution is still not
      started, it will be executed only once.
-   * If this tasklet is already running on another CPU (or schedule is called
-     from tasklet itself), it is rescheduled for later.
+   * If this tasklet is already running on another CPU, it is rescheduled
+     for later.
+   * Schedule must not be called from the tasklet itself (a lockup occurs)
    * Tasklet is strictly serialized wrt itself, but not
      wrt another tasklets. If client needs some intertask synchronization,
      he makes it with spinlocks.
@@ -558,27 +584,36 @@ struct tasklet_struct name = { NULL, 0,
 enum
 {
 	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
-	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
+	TASKLET_STATE_RUN,	/* Tasklet is running (SMP only) */
+	TASKLET_STATE_PENDING	/* Tasklet is pending */
 };
 
-#ifdef CONFIG_SMP
+#define TASKLET_STATEF_SCHED	(1 << TASKLET_STATE_SCHED)
+#define TASKLET_STATEF_RUN	(1 << TASKLET_STATE_RUN)
+#define TASKLET_STATEF_PENDING	(1 << TASKLET_STATE_PENDING)
+
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
 static inline int tasklet_trylock(struct tasklet_struct *t)
 {
 	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 }
 
+static inline int tasklet_tryunlock(struct tasklet_struct *t)
+{
+	return cmpxchg(&t->state, TASKLET_STATEF_RUN, 0) == TASKLET_STATEF_RUN;
+}
+
 static inline void tasklet_unlock(struct tasklet_struct *t)
 {
 	smp_mb__before_atomic();
 	clear_bit(TASKLET_STATE_RUN, &(t)->state);
 }
 
-static inline void tasklet_unlock_wait(struct tasklet_struct *t)
-{
-	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
-}
+extern void tasklet_unlock_wait(struct tasklet_struct *t);
+
 #else
 #define tasklet_trylock(t) 1
+#define tasklet_tryunlock(t)	1
 #define tasklet_unlock_wait(t) do { } while (0)
 #define tasklet_unlock(t) do { } while (0)
 #endif
@@ -612,17 +647,18 @@ static inline void tasklet_disable(struc
 	smp_mb();
 }
 
-static inline void tasklet_enable(struct tasklet_struct *t)
-{
-	smp_mb__before_atomic();
-	atomic_dec(&t->count);
-}
-
+extern void tasklet_enable(struct tasklet_struct *t);
 extern void tasklet_kill(struct tasklet_struct *t);
 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 extern void tasklet_init(struct tasklet_struct *t,
 			 void (*func)(unsigned long), unsigned long data);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void softirq_early_init(void);
+#else
+static inline void softirq_early_init(void) { }
+#endif
+
 struct tasklet_hrtimer {
 	struct hrtimer		timer;
 	struct tasklet_struct	tasklet;
Index: linux-4.19.25-rt16/include/linux/irq.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/irq.h
+++ linux-4.19.25-rt16/include/linux/irq.h
@@ -69,6 +69,7 @@ enum irqchip_irq_state;
  * IRQ_IS_POLLED		- Always polled by another interrupt. Exclude
  *				  it from the spurious interrupt detection
  *				  mechanism and from core side polling.
+ * IRQ_NO_SOFTIRQ_CALL		- No softirq processing in the irq thread context (RT)
  * IRQ_DISABLE_UNLAZY		- Disable lazy irq disable
  */
 enum {
@@ -96,13 +97,14 @@ enum {
 	IRQ_PER_CPU_DEVID	= (1 << 17),
 	IRQ_IS_POLLED		= (1 << 18),
 	IRQ_DISABLE_UNLAZY	= (1 << 19),
+	IRQ_NO_SOFTIRQ_CALL	= (1 << 20),
 };
 
 #define IRQF_MODIFY_MASK	\
 	(IRQ_TYPE_SENSE_MASK | IRQ_NOPROBE | IRQ_NOREQUEST | \
 	 IRQ_NOAUTOEN | IRQ_MOVE_PCNTXT | IRQ_LEVEL | IRQ_NO_BALANCING | \
 	 IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID | \
-	 IRQ_IS_POLLED | IRQ_DISABLE_UNLAZY)
+	 IRQ_IS_POLLED | IRQ_DISABLE_UNLAZY | IRQ_NO_SOFTIRQ_CALL)
 
 #define IRQ_NO_BALANCING_MASK	(IRQ_PER_CPU | IRQ_NO_BALANCING)
 
Index: linux-4.19.25-rt16/include/linux/irq_work.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/irq_work.h
+++ linux-4.19.25-rt16/include/linux/irq_work.h
@@ -18,6 +18,8 @@
 
 /* Doesn't want IPI, wait for tick: */
 #define IRQ_WORK_LAZY		BIT(2)
+/* Run hard IRQ context, even on RT */
+#define IRQ_WORK_HARD_IRQ	BIT(3)
 
 #define IRQ_WORK_CLAIMED	(IRQ_WORK_PENDING | IRQ_WORK_BUSY)
 
@@ -52,4 +54,10 @@ static inline bool irq_work_needs_cpu(vo
 static inline void irq_work_run(void) { }
 #endif
 
+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
+void irq_work_tick_soft(void);
+#else
+static inline void irq_work_tick_soft(void) { }
+#endif
+
 #endif /* _LINUX_IRQ_WORK_H */
Index: linux-4.19.25-rt16/include/linux/irqchip/arm-gic-v3.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/irqchip/arm-gic-v3.h
+++ linux-4.19.25-rt16/include/linux/irqchip/arm-gic-v3.h
@@ -585,6 +585,7 @@ struct rdists {
 		void __iomem	*rd_base;
 		struct page	*pend_page;
 		phys_addr_t	phys_base;
+		bool		lpi_enabled;
 	} __percpu		*rdist;
 	struct page		*prop_page;
 	u64			flags;
Index: linux-4.19.25-rt16/include/linux/irqdesc.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/irqdesc.h
+++ linux-4.19.25-rt16/include/linux/irqdesc.h
@@ -71,6 +71,7 @@ struct irq_desc {
 	unsigned int		irqs_unhandled;
 	atomic_t		threads_handled;
 	int			threads_handled_last;
+	u64			random_ip;
 	raw_spinlock_t		lock;
 	struct cpumask		*percpu_enabled;
 	const struct cpumask	*percpu_affinity;
Index: linux-4.19.25-rt16/include/linux/irqflags.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/irqflags.h
+++ linux-4.19.25-rt16/include/linux/irqflags.h
@@ -43,14 +43,6 @@ do {						\
 do {						\
 	current->hardirq_context--;		\
 } while (0)
-# define lockdep_softirq_enter()		\
-do {						\
-	current->softirq_context++;		\
-} while (0)
-# define lockdep_softirq_exit()			\
-do {						\
-	current->softirq_context--;		\
-} while (0)
 #else
 # define trace_hardirqs_on()		do { } while (0)
 # define trace_hardirqs_off()		do { } while (0)
@@ -63,6 +55,21 @@ do {						\
 # define lockdep_softirq_enter()	do { } while (0)
 # define lockdep_softirq_exit()		do { } while (0)
 #endif
+
+#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT_FULL)
+# define lockdep_softirq_enter()		\
+do {						\
+	current->softirq_context++;		\
+} while (0)
+# define lockdep_softirq_exit()			\
+do {						\
+	current->softirq_context--;		\
+} while (0)
+
+#else
+# define lockdep_softirq_enter()	do { } while (0)
+# define lockdep_softirq_exit()		do { } while (0)
+#endif
 
 #if defined(CONFIG_IRQSOFF_TRACER) || \
 	defined(CONFIG_PREEMPT_TRACER)
Index: linux-4.19.25-rt16/include/linux/jbd2.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/jbd2.h
+++ linux-4.19.25-rt16/include/linux/jbd2.h
@@ -347,32 +347,56 @@ static inline struct journal_head *bh2jh
 
 static inline void jbd_lock_bh_state(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_lock(BH_State, &bh->b_state);
+#else
+	spin_lock(&bh->b_state_lock);
+#endif
 }
 
 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	return bit_spin_trylock(BH_State, &bh->b_state);
+#else
+	return spin_trylock(&bh->b_state_lock);
+#endif
 }
 
 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	return bit_spin_is_locked(BH_State, &bh->b_state);
+#else
+	return spin_is_locked(&bh->b_state_lock);
+#endif
 }
 
 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_unlock(BH_State, &bh->b_state);
+#else
+	spin_unlock(&bh->b_state_lock);
+#endif
 }
 
 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_lock(BH_JournalHead, &bh->b_state);
+#else
+	spin_lock(&bh->b_journal_head_lock);
+#endif
 }
 
 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_unlock(BH_JournalHead, &bh->b_state);
+#else
+	spin_unlock(&bh->b_journal_head_lock);
+#endif
 }
 
 #define J_ASSERT(assert)	BUG_ON(!(assert))
Index: linux-4.19.25-rt16/include/linux/kdb.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/kdb.h
+++ linux-4.19.25-rt16/include/linux/kdb.h
@@ -167,6 +167,7 @@ extern __printf(2, 0) int vkdb_printf(en
 extern __printf(1, 2) int kdb_printf(const char *, ...);
 typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);
 
+#define in_kdb_printk()	(kdb_trap_printk)
 extern void kdb_init(int level);
 
 /* Access to kdb specific polling devices */
@@ -201,6 +202,7 @@ extern int kdb_register_flags(char *, kd
 extern int kdb_unregister(char *);
 #else /* ! CONFIG_KGDB_KDB */
 static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
+#define in_kdb_printk() (0)
 static inline void kdb_init(int level) {}
 static inline int kdb_register(char *cmd, kdb_func_t func, char *usage,
 			       char *help, short minlen) { return 0; }
Index: linux-4.19.25-rt16/include/linux/kernel.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/kernel.h
+++ linux-4.19.25-rt16/include/linux/kernel.h
@@ -259,6 +259,9 @@ extern int _cond_resched(void);
  */
 # define might_sleep() \
 	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
+
+# define might_sleep_no_state_check() \
+	do { ___might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
 # define sched_annotate_sleep()	(current->task_state_change = 0)
 #else
   static inline void ___might_sleep(const char *file, int line,
@@ -266,6 +269,7 @@ extern int _cond_resched(void);
   static inline void __might_sleep(const char *file, int line,
 				   int preempt_offset) { }
 # define might_sleep() do { might_resched(); } while (0)
+# define might_sleep_no_state_check() do { might_resched(); } while (0)
 # define sched_annotate_sleep() do { } while (0)
 #endif
 
Index: linux-4.19.25-rt16/include/linux/kthread.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/kthread.h
+++ linux-4.19.25-rt16/include/linux/kthread.h
@@ -85,7 +85,7 @@ enum {
 
 struct kthread_worker {
 	unsigned int		flags;
-	spinlock_t		lock;
+	raw_spinlock_t		lock;
 	struct list_head	work_list;
 	struct list_head	delayed_work_list;
 	struct task_struct	*task;
Index: linux-4.19.25-rt16/include/linux/list_bl.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/list_bl.h
+++ linux-4.19.25-rt16/include/linux/list_bl.h
@@ -3,6 +3,7 @@
 #define _LINUX_LIST_BL_H
 
 #include <linux/list.h>
+#include <linux/spinlock.h>
 #include <linux/bit_spinlock.h>
 
 /*
@@ -33,13 +34,24 @@
 
 struct hlist_bl_head {
 	struct hlist_bl_node *first;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	raw_spinlock_t lock;
+#endif
 };
 
 struct hlist_bl_node {
 	struct hlist_bl_node *next, **pprev;
 };
-#define INIT_HLIST_BL_HEAD(ptr) \
-	((ptr)->first = NULL)
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+#define INIT_HLIST_BL_HEAD(h)		\
+do {					\
+	(h)->first = NULL;		\
+	raw_spin_lock_init(&(h)->lock);	\
+} while (0)
+#else
+#define INIT_HLIST_BL_HEAD(h) (h)->first = NULL
+#endif
 
 static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h)
 {
@@ -119,12 +131,26 @@ static inline void hlist_bl_del_init(str
 
 static inline void hlist_bl_lock(struct hlist_bl_head *b)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_lock(0, (unsigned long *)b);
+#else
+	raw_spin_lock(&b->lock);
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+	__set_bit(0, (unsigned long *)b);
+#endif
+#endif
 }
 
 static inline void hlist_bl_unlock(struct hlist_bl_head *b)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	__bit_spin_unlock(0, (unsigned long *)b);
+#else
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+	__clear_bit(0, (unsigned long *)b);
+#endif
+	raw_spin_unlock(&b->lock);
+#endif
 }
 
 static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
Index: linux-4.19.25-rt16/include/linux/locallock.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/locallock.h
@@ -0,0 +1,281 @@
+#ifndef _LINUX_LOCALLOCK_H
+#define _LINUX_LOCALLOCK_H
+
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define LL_WARN(cond)	WARN_ON(cond)
+#else
+# define LL_WARN(cond)	do { } while (0)
+#endif
+
+/*
+ * per cpu lock based substitute for local_irq_*()
+ */
+struct local_irq_lock {
+	spinlock_t		lock;
+	struct task_struct	*owner;
+	int			nestcnt;
+	unsigned long		flags;
+};
+
+#define DEFINE_LOCAL_IRQ_LOCK(lvar)					\
+	DEFINE_PER_CPU(struct local_irq_lock, lvar) = {			\
+		.lock = __SPIN_LOCK_UNLOCKED((lvar).lock) }
+
+#define DECLARE_LOCAL_IRQ_LOCK(lvar)					\
+	DECLARE_PER_CPU(struct local_irq_lock, lvar)
+
+#define local_irq_lock_init(lvar)					\
+	do {								\
+		int __cpu;						\
+		for_each_possible_cpu(__cpu)				\
+			spin_lock_init(&per_cpu(lvar, __cpu).lock);	\
+	} while (0)
+
+static inline void __local_lock(struct local_irq_lock *lv)
+{
+	if (lv->owner != current) {
+		spin_lock(&lv->lock);
+		LL_WARN(lv->owner);
+		LL_WARN(lv->nestcnt);
+		lv->owner = current;
+	}
+	lv->nestcnt++;
+}
+
+#define local_lock(lvar)					\
+	do { __local_lock(&get_local_var(lvar)); } while (0)
+
+#define local_lock_on(lvar, cpu)				\
+	do { __local_lock(&per_cpu(lvar, cpu)); } while (0)
+
+static inline int __local_trylock(struct local_irq_lock *lv)
+{
+	if (lv->owner != current && spin_trylock(&lv->lock)) {
+		LL_WARN(lv->owner);
+		LL_WARN(lv->nestcnt);
+		lv->owner = current;
+		lv->nestcnt = 1;
+		return 1;
+	} else if (lv->owner == current) {
+		lv->nestcnt++;
+		return 1;
+	}
+	return 0;
+}
+
+#define local_trylock(lvar)						\
+	({								\
+		int __locked;						\
+		__locked = __local_trylock(&get_local_var(lvar));	\
+		if (!__locked)						\
+			put_local_var(lvar);				\
+		__locked;						\
+	})
+
+static inline void __local_unlock(struct local_irq_lock *lv)
+{
+	LL_WARN(lv->nestcnt == 0);
+	LL_WARN(lv->owner != current);
+	if (--lv->nestcnt)
+		return;
+
+	lv->owner = NULL;
+	spin_unlock(&lv->lock);
+}
+
+#define local_unlock(lvar)					\
+	do {							\
+		__local_unlock(this_cpu_ptr(&lvar));		\
+		put_local_var(lvar);				\
+	} while (0)
+
+#define local_unlock_on(lvar, cpu)                       \
+	do { __local_unlock(&per_cpu(lvar, cpu)); } while (0)
+
+static inline void __local_lock_irq(struct local_irq_lock *lv)
+{
+	spin_lock_irqsave(&lv->lock, lv->flags);
+	LL_WARN(lv->owner);
+	LL_WARN(lv->nestcnt);
+	lv->owner = current;
+	lv->nestcnt = 1;
+}
+
+#define local_lock_irq(lvar)						\
+	do { __local_lock_irq(&get_local_var(lvar)); } while (0)
+
+#define local_lock_irq_on(lvar, cpu)					\
+	do { __local_lock_irq(&per_cpu(lvar, cpu)); } while (0)
+
+static inline void __local_unlock_irq(struct local_irq_lock *lv)
+{
+	LL_WARN(!lv->nestcnt);
+	LL_WARN(lv->owner != current);
+	lv->owner = NULL;
+	lv->nestcnt = 0;
+	spin_unlock_irq(&lv->lock);
+}
+
+#define local_unlock_irq(lvar)						\
+	do {								\
+		__local_unlock_irq(this_cpu_ptr(&lvar));		\
+		put_local_var(lvar);					\
+	} while (0)
+
+#define local_unlock_irq_on(lvar, cpu)					\
+	do {								\
+		__local_unlock_irq(&per_cpu(lvar, cpu));		\
+	} while (0)
+
+static inline int __local_lock_irqsave(struct local_irq_lock *lv)
+{
+	if (lv->owner != current) {
+		__local_lock_irq(lv);
+		return 0;
+	} else {
+		lv->nestcnt++;
+		return 1;
+	}
+}
+
+#define local_lock_irqsave(lvar, _flags)				\
+	do {								\
+		if (__local_lock_irqsave(&get_local_var(lvar)))		\
+			put_local_var(lvar);				\
+		_flags = __this_cpu_read(lvar.flags);			\
+	} while (0)
+
+#define local_lock_irqsave_on(lvar, _flags, cpu)			\
+	do {								\
+		__local_lock_irqsave(&per_cpu(lvar, cpu));		\
+		_flags = per_cpu(lvar, cpu).flags;			\
+	} while (0)
+
+static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,
+					    unsigned long flags)
+{
+	LL_WARN(!lv->nestcnt);
+	LL_WARN(lv->owner != current);
+	if (--lv->nestcnt)
+		return 0;
+
+	lv->owner = NULL;
+	spin_unlock_irqrestore(&lv->lock, lv->flags);
+	return 1;
+}
+
+#define local_unlock_irqrestore(lvar, flags)				\
+	do {								\
+		if (__local_unlock_irqrestore(this_cpu_ptr(&lvar), flags)) \
+			put_local_var(lvar);				\
+	} while (0)
+
+#define local_unlock_irqrestore_on(lvar, flags, cpu)			\
+	do {								\
+		__local_unlock_irqrestore(&per_cpu(lvar, cpu), flags);	\
+	} while (0)
+
+#define local_spin_trylock_irq(lvar, lock)				\
+	({								\
+		int __locked;						\
+		local_lock_irq(lvar);					\
+		__locked = spin_trylock(lock);				\
+		if (!__locked)						\
+			local_unlock_irq(lvar);				\
+		__locked;						\
+	})
+
+#define local_spin_lock_irq(lvar, lock)					\
+	do {								\
+		local_lock_irq(lvar);					\
+		spin_lock(lock);					\
+	} while (0)
+
+#define local_spin_unlock_irq(lvar, lock)				\
+	do {								\
+		spin_unlock(lock);					\
+		local_unlock_irq(lvar);					\
+	} while (0)
+
+#define local_spin_lock_irqsave(lvar, lock, flags)			\
+	do {								\
+		local_lock_irqsave(lvar, flags);			\
+		spin_lock(lock);					\
+	} while (0)
+
+#define local_spin_unlock_irqrestore(lvar, lock, flags)			\
+	do {								\
+		spin_unlock(lock);					\
+		local_unlock_irqrestore(lvar, flags);			\
+	} while (0)
+
+#define get_locked_var(lvar, var)					\
+	(*({								\
+		local_lock(lvar);					\
+		this_cpu_ptr(&var);					\
+	}))
+
+#define put_locked_var(lvar, var)	local_unlock(lvar);
+
+#define get_locked_ptr(lvar, var)					\
+	({								\
+		local_lock(lvar);					\
+		this_cpu_ptr(var);					\
+	})
+
+#define put_locked_ptr(lvar, var)	local_unlock(lvar);
+
+#define local_lock_cpu(lvar)						\
+	({								\
+		local_lock(lvar);					\
+		smp_processor_id();					\
+	})
+
+#define local_unlock_cpu(lvar)			local_unlock(lvar)
+
+#else /* PREEMPT_RT_BASE */
+
+#define DEFINE_LOCAL_IRQ_LOCK(lvar)		__typeof__(const int) lvar
+#define DECLARE_LOCAL_IRQ_LOCK(lvar)		extern __typeof__(const int) lvar
+
+static inline void local_irq_lock_init(int lvar) { }
+
+#define local_trylock(lvar)					\
+	({							\
+		preempt_disable();				\
+		1;						\
+	})
+
+#define local_lock(lvar)			preempt_disable()
+#define local_unlock(lvar)			preempt_enable()
+#define local_lock_irq(lvar)			local_irq_disable()
+#define local_lock_irq_on(lvar, cpu)		local_irq_disable()
+#define local_unlock_irq(lvar)			local_irq_enable()
+#define local_unlock_irq_on(lvar, cpu)		local_irq_enable()
+#define local_lock_irqsave(lvar, flags)		local_irq_save(flags)
+#define local_unlock_irqrestore(lvar, flags)	local_irq_restore(flags)
+
+#define local_spin_trylock_irq(lvar, lock)	spin_trylock_irq(lock)
+#define local_spin_lock_irq(lvar, lock)		spin_lock_irq(lock)
+#define local_spin_unlock_irq(lvar, lock)	spin_unlock_irq(lock)
+#define local_spin_lock_irqsave(lvar, lock, flags)	\
+	spin_lock_irqsave(lock, flags)
+#define local_spin_unlock_irqrestore(lvar, lock, flags)	\
+	spin_unlock_irqrestore(lock, flags)
+
+#define get_locked_var(lvar, var)		get_cpu_var(var)
+#define put_locked_var(lvar, var)		put_cpu_var(var)
+#define get_locked_ptr(lvar, var)		get_cpu_ptr(var)
+#define put_locked_ptr(lvar, var)		put_cpu_ptr(var)
+
+#define local_lock_cpu(lvar)			get_cpu()
+#define local_unlock_cpu(lvar)			put_cpu()
+
+#endif
+
+#endif
Index: linux-4.19.25-rt16/include/linux/mm_types.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/mm_types.h
+++ linux-4.19.25-rt16/include/linux/mm_types.h
@@ -12,6 +12,7 @@
 #include <linux/completion.h>
 #include <linux/cpumask.h>
 #include <linux/uprobes.h>
+#include <linux/rcupdate.h>
 #include <linux/page-flags-layout.h>
 #include <linux/workqueue.h>
 
@@ -482,6 +483,9 @@ struct mm_struct {
 		bool tlb_flush_batched;
 #endif
 		struct uprobes_state uprobes_state;
+#ifdef CONFIG_PREEMPT_RT_BASE
+		struct rcu_head delayed_drop;
+#endif
 #ifdef CONFIG_HUGETLB_PAGE
 		atomic_long_t hugetlb_usage;
 #endif
Index: linux-4.19.25-rt16/include/linux/mutex.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/mutex.h
+++ linux-4.19.25-rt16/include/linux/mutex.h
@@ -22,6 +22,17 @@
 
 struct ww_acquire_ctx;
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
+		, .dep_map = { .name = #lockname }
+#else
+# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
+#endif
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/mutex_rt.h>
+#else
+
 /*
  * Simple, straightforward mutexes with strict semantics:
  *
@@ -118,13 +129,6 @@ do {									\
 	__mutex_init((mutex), #mutex, &__key);				\
 } while (0)
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
-		, .dep_map = { .name = #lockname }
-#else
-# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
-#endif
-
 #define __MUTEX_INITIALIZER(lockname) \
 		{ .owner = ATOMIC_LONG_INIT(0) \
 		, .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
@@ -229,4 +233,6 @@ mutex_trylock_recursive(struct mutex *lo
 	return mutex_trylock(lock);
 }
 
+#endif /* !PREEMPT_RT_FULL */
+
 #endif /* __LINUX_MUTEX_H */
Index: linux-4.19.25-rt16/include/linux/mutex_rt.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/mutex_rt.h
@@ -0,0 +1,130 @@
+#ifndef __LINUX_MUTEX_RT_H
+#define __LINUX_MUTEX_RT_H
+
+#ifndef __LINUX_MUTEX_H
+#error "Please include mutex.h"
+#endif
+
+#include <linux/rtmutex.h>
+
+/* FIXME: Just for __lockfunc */
+#include <linux/spinlock.h>
+
+struct mutex {
+	struct rt_mutex		lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+};
+
+#define __MUTEX_INITIALIZER(mutexname)					\
+	{								\
+		.lock = __RT_MUTEX_INITIALIZER(mutexname.lock)		\
+		__DEP_MAP_MUTEX_INITIALIZER(mutexname)			\
+	}
+
+#define DEFINE_MUTEX(mutexname)						\
+	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
+
+extern void __mutex_do_init(struct mutex *lock, const char *name, struct lock_class_key *key);
+extern void __lockfunc _mutex_lock(struct mutex *lock);
+extern void __lockfunc _mutex_lock_io(struct mutex *lock);
+extern void __lockfunc _mutex_lock_io_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_lock_interruptible(struct mutex *lock);
+extern int __lockfunc _mutex_lock_killable(struct mutex *lock);
+extern void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass);
+extern void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
+extern int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_trylock(struct mutex *lock);
+extern void __lockfunc _mutex_unlock(struct mutex *lock);
+
+#define mutex_is_locked(l)		rt_mutex_is_locked(&(l)->lock)
+#define mutex_lock(l)			_mutex_lock(l)
+#define mutex_lock_interruptible(l)	_mutex_lock_interruptible(l)
+#define mutex_lock_killable(l)		_mutex_lock_killable(l)
+#define mutex_trylock(l)		_mutex_trylock(l)
+#define mutex_unlock(l)			_mutex_unlock(l)
+#define mutex_lock_io(l)		_mutex_lock_io(l);
+
+#define __mutex_owner(l)		((l)->lock.owner)
+
+#ifdef CONFIG_DEBUG_MUTEXES
+#define mutex_destroy(l)		rt_mutex_destroy(&(l)->lock)
+#else
+static inline void mutex_destroy(struct mutex *lock) {}
+#endif
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define mutex_lock_nested(l, s)	_mutex_lock_nested(l, s)
+# define mutex_lock_interruptible_nested(l, s) \
+					_mutex_lock_interruptible_nested(l, s)
+# define mutex_lock_killable_nested(l, s) \
+					_mutex_lock_killable_nested(l, s)
+# define mutex_lock_io_nested(l, s)	_mutex_lock_io_nested(l, s)
+
+# define mutex_lock_nest_lock(lock, nest_lock)				\
+do {									\
+	typecheck(struct lockdep_map *, &(nest_lock)->dep_map);		\
+	_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map);		\
+} while (0)
+
+#else
+# define mutex_lock_nested(l, s)	_mutex_lock(l)
+# define mutex_lock_interruptible_nested(l, s) \
+					_mutex_lock_interruptible(l)
+# define mutex_lock_killable_nested(l, s) \
+					_mutex_lock_killable(l)
+# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
+# define mutex_lock_io_nested(l, s)	_mutex_lock_io(l)
+#endif
+
+# define mutex_init(mutex)				\
+do {							\
+	static struct lock_class_key __key;		\
+							\
+	rt_mutex_init(&(mutex)->lock);			\
+	__mutex_do_init((mutex), #mutex, &__key);	\
+} while (0)
+
+# define __mutex_init(mutex, name, key)			\
+do {							\
+	rt_mutex_init(&(mutex)->lock);			\
+	__mutex_do_init((mutex), name, key);		\
+} while (0)
+
+/**
+ * These values are chosen such that FAIL and SUCCESS match the
+ * values of the regular mutex_trylock().
+ */
+enum mutex_trylock_recursive_enum {
+	MUTEX_TRYLOCK_FAILED    = 0,
+	MUTEX_TRYLOCK_SUCCESS   = 1,
+	MUTEX_TRYLOCK_RECURSIVE,
+};
+/**
+ * mutex_trylock_recursive - trylock variant that allows recursive locking
+ * @lock: mutex to be locked
+ *
+ * This function should not be used, _ever_. It is purely for hysterical GEM
+ * raisins, and once those are gone this will be removed.
+ *
+ * Returns:
+ *  MUTEX_TRYLOCK_FAILED    - trylock failed,
+ *  MUTEX_TRYLOCK_SUCCESS   - lock acquired,
+ *  MUTEX_TRYLOCK_RECURSIVE - we already owned the lock.
+ */
+int __rt_mutex_owner_current(struct rt_mutex *lock);
+
+static inline /* __deprecated */ __must_check enum mutex_trylock_recursive_enum
+mutex_trylock_recursive(struct mutex *lock)
+{
+	if (unlikely(__rt_mutex_owner_current(&lock->lock)))
+		return MUTEX_TRYLOCK_RECURSIVE;
+
+	return mutex_trylock(lock);
+}
+
+extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
+
+#endif
Index: linux-4.19.25-rt16/include/linux/netdevice.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/netdevice.h
+++ linux-4.19.25-rt16/include/linux/netdevice.h
@@ -422,7 +422,19 @@ typedef enum rx_handler_result rx_handle
 typedef rx_handler_result_t rx_handler_func_t(struct sk_buff **pskb);
 
 void __napi_schedule(struct napi_struct *n);
+
+/*
+ * When PREEMPT_RT_FULL is defined, all device interrupt handlers
+ * run as threads, and they can also be preempted (without PREEMPT_RT
+ * interrupt threads can not be preempted). Which means that calling
+ * __napi_schedule_irqoff() from an interrupt handler can be preempted
+ * and can corrupt the napi->poll_list.
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+#define __napi_schedule_irqoff(n) __napi_schedule(n)
+#else
 void __napi_schedule_irqoff(struct napi_struct *n);
+#endif
 
 static inline bool napi_disable_pending(struct napi_struct *n)
 {
@@ -587,7 +599,11 @@ struct netdev_queue {
  * write-mostly part
  */
 	spinlock_t		_xmit_lock ____cacheline_aligned_in_smp;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	struct task_struct	*xmit_lock_owner;
+#else
 	int			xmit_lock_owner;
+#endif
 	/*
 	 * Time (in jiffies) of last Tx
 	 */
@@ -2611,14 +2627,53 @@ void netdev_freemem(struct net_device *d
 void synchronize_net(void);
 int init_dummy_netdev(struct net_device *dev);
 
-DECLARE_PER_CPU(int, xmit_recursion);
 #define XMIT_RECURSION_LIMIT	10
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline int dev_recursion_level(void)
+{
+	return current->xmit_recursion;
+}
+
+static inline int xmit_rec_read(void)
+{
+	return current->xmit_recursion;
+}
+
+static inline void xmit_rec_inc(void)
+{
+	current->xmit_recursion++;
+}
+
+static inline void xmit_rec_dec(void)
+{
+	current->xmit_recursion--;
+}
+
+#else
+
+DECLARE_PER_CPU(int, xmit_recursion);
 
 static inline int dev_recursion_level(void)
 {
 	return this_cpu_read(xmit_recursion);
 }
 
+static inline int xmit_rec_read(void)
+{
+	return __this_cpu_read(xmit_recursion);
+}
+
+static inline void xmit_rec_inc(void)
+{
+	__this_cpu_inc(xmit_recursion);
+}
+
+static inline void xmit_rec_dec(void)
+{
+	__this_cpu_dec(xmit_recursion);
+}
+#endif
+
 struct net_device *dev_get_by_index(struct net *net, int ifindex);
 struct net_device *__dev_get_by_index(struct net *net, int ifindex);
 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex);
@@ -2973,6 +3028,7 @@ struct softnet_data {
 	unsigned int		dropped;
 	struct sk_buff_head	input_pkt_queue;
 	struct napi_struct	backlog;
+	struct sk_buff_head	tofree_queue;
 
 };
 
@@ -3793,10 +3849,48 @@ static inline u32 netif_msg_init(int deb
 	return (1 << debug_value) - 1;
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline void netdev_queue_set_owner(struct netdev_queue *txq, int cpu)
+{
+	txq->xmit_lock_owner = current;
+}
+
+static inline void netdev_queue_clear_owner(struct netdev_queue *txq)
+{
+	txq->xmit_lock_owner = NULL;
+}
+
+static inline bool netdev_queue_has_owner(struct netdev_queue *txq)
+{
+	if (txq->xmit_lock_owner != NULL)
+		return true;
+	return false;
+}
+
+#else
+
+static inline void netdev_queue_set_owner(struct netdev_queue *txq, int cpu)
+{
+	txq->xmit_lock_owner = cpu;
+}
+
+static inline void netdev_queue_clear_owner(struct netdev_queue *txq)
+{
+	txq->xmit_lock_owner = -1;
+}
+
+static inline bool netdev_queue_has_owner(struct netdev_queue *txq)
+{
+	if (txq->xmit_lock_owner != -1)
+		return true;
+	return false;
+}
+#endif
+
 static inline void __netif_tx_lock(struct netdev_queue *txq, int cpu)
 {
 	spin_lock(&txq->_xmit_lock);
-	txq->xmit_lock_owner = cpu;
+	netdev_queue_set_owner(txq, cpu);
 }
 
 static inline bool __netif_tx_acquire(struct netdev_queue *txq)
@@ -3813,32 +3907,32 @@ static inline void __netif_tx_release(st
 static inline void __netif_tx_lock_bh(struct netdev_queue *txq)
 {
 	spin_lock_bh(&txq->_xmit_lock);
-	txq->xmit_lock_owner = smp_processor_id();
+	netdev_queue_set_owner(txq, smp_processor_id());
 }
 
 static inline bool __netif_tx_trylock(struct netdev_queue *txq)
 {
 	bool ok = spin_trylock(&txq->_xmit_lock);
 	if (likely(ok))
-		txq->xmit_lock_owner = smp_processor_id();
+		netdev_queue_set_owner(txq, smp_processor_id());
 	return ok;
 }
 
 static inline void __netif_tx_unlock(struct netdev_queue *txq)
 {
-	txq->xmit_lock_owner = -1;
+	netdev_queue_clear_owner(txq);
 	spin_unlock(&txq->_xmit_lock);
 }
 
 static inline void __netif_tx_unlock_bh(struct netdev_queue *txq)
 {
-	txq->xmit_lock_owner = -1;
+	netdev_queue_clear_owner(txq);
 	spin_unlock_bh(&txq->_xmit_lock);
 }
 
 static inline void txq_trans_update(struct netdev_queue *txq)
 {
-	if (txq->xmit_lock_owner != -1)
+	if (netdev_queue_has_owner(txq))
 		txq->trans_start = jiffies;
 }
 
Index: linux-4.19.25-rt16/include/linux/netfilter/x_tables.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/netfilter/x_tables.h
+++ linux-4.19.25-rt16/include/linux/netfilter/x_tables.h
@@ -6,6 +6,7 @@
 #include <linux/netdevice.h>
 #include <linux/static_key.h>
 #include <linux/netfilter.h>
+#include <linux/locallock.h>
 #include <uapi/linux/netfilter/x_tables.h>
 
 /* Test a struct->invflags and a boolean for inequality */
@@ -345,6 +346,8 @@ void xt_free_table_info(struct xt_table_
  */
 DECLARE_PER_CPU(seqcount_t, xt_recseq);
 
+DECLARE_LOCAL_IRQ_LOCK(xt_write_lock);
+
 /* xt_tee_enabled - true if x_tables needs to handle reentrancy
  *
  * Enabled if current ip(6)tables ruleset has at least one -j TEE rule.
@@ -365,6 +368,9 @@ static inline unsigned int xt_write_recs
 {
 	unsigned int addend;
 
+	/* RT protection */
+	local_lock(xt_write_lock);
+
 	/*
 	 * Low order bit of sequence is set if we already
 	 * called xt_write_recseq_begin().
@@ -395,6 +401,7 @@ static inline void xt_write_recseq_end(u
 	/* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
 	smp_wmb();
 	__this_cpu_add(xt_recseq.sequence, addend);
+	local_unlock(xt_write_lock);
 }
 
 /*
Index: linux-4.19.25-rt16/include/linux/nfs_fs.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/nfs_fs.h
+++ linux-4.19.25-rt16/include/linux/nfs_fs.h
@@ -163,7 +163,11 @@ struct nfs_inode {
 
 	/* Readers: in-flight sillydelete RPC calls */
 	/* Writers: rmdir */
+#ifdef CONFIG_PREEMPT_RT_BASE
+	struct semaphore        rmdir_sem;
+#else
 	struct rw_semaphore	rmdir_sem;
+#endif
 	struct mutex		commit_mutex;
 
 #if IS_ENABLED(CONFIG_NFS_V4)
Index: linux-4.19.25-rt16/include/linux/nfs_xdr.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/nfs_xdr.h
+++ linux-4.19.25-rt16/include/linux/nfs_xdr.h
@@ -1549,7 +1549,7 @@ struct nfs_unlinkdata {
 	struct nfs_removeargs args;
 	struct nfs_removeres res;
 	struct dentry *dentry;
-	wait_queue_head_t wq;
+	struct swait_queue_head wq;
 	struct rpc_cred	*cred;
 	struct nfs_fattr dir_attr;
 	long timeout;
Index: linux-4.19.25-rt16/include/linux/percpu-rwsem.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/percpu-rwsem.h
+++ linux-4.19.25-rt16/include/linux/percpu-rwsem.h
@@ -29,7 +29,7 @@ static struct percpu_rw_semaphore name =
 extern int __percpu_down_read(struct percpu_rw_semaphore *, int);
 extern void __percpu_up_read(struct percpu_rw_semaphore *);
 
-static inline void percpu_down_read_preempt_disable(struct percpu_rw_semaphore *sem)
+static inline void percpu_down_read(struct percpu_rw_semaphore *sem)
 {
 	might_sleep();
 
@@ -47,16 +47,10 @@ static inline void percpu_down_read_pree
 	__this_cpu_inc(*sem->read_count);
 	if (unlikely(!rcu_sync_is_idle(&sem->rss)))
 		__percpu_down_read(sem, false); /* Unconditional memory barrier */
-	barrier();
 	/*
-	 * The barrier() prevents the compiler from
+	 * The preempt_enable() prevents the compiler from
 	 * bleeding the critical section out.
 	 */
-}
-
-static inline void percpu_down_read(struct percpu_rw_semaphore *sem)
-{
-	percpu_down_read_preempt_disable(sem);
 	preempt_enable();
 }
 
@@ -83,13 +77,9 @@ static inline int percpu_down_read_trylo
 	return ret;
 }
 
-static inline void percpu_up_read_preempt_enable(struct percpu_rw_semaphore *sem)
+static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
 {
-	/*
-	 * The barrier() prevents the compiler from
-	 * bleeding the critical section out.
-	 */
-	barrier();
+	preempt_disable();
 	/*
 	 * Same as in percpu_down_read().
 	 */
@@ -102,12 +92,6 @@ static inline void percpu_up_read_preemp
 	rwsem_release(&sem->rw_sem.dep_map, 1, _RET_IP_);
 }
 
-static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
-{
-	preempt_disable();
-	percpu_up_read_preempt_enable(sem);
-}
-
 extern void percpu_down_write(struct percpu_rw_semaphore *);
 extern void percpu_up_write(struct percpu_rw_semaphore *);
 
Index: linux-4.19.25-rt16/include/linux/percpu.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/percpu.h
+++ linux-4.19.25-rt16/include/linux/percpu.h
@@ -19,6 +19,35 @@
 #define PERCPU_MODULE_RESERVE		0
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+
+#define get_local_var(var) (*({	\
+	migrate_disable();	\
+	this_cpu_ptr(&var);	}))
+
+#define put_local_var(var) do {	\
+	(void)&(var);		\
+	migrate_enable();	\
+} while (0)
+
+# define get_local_ptr(var) ({	\
+	migrate_disable();	\
+	this_cpu_ptr(var);	})
+
+# define put_local_ptr(var) do {	\
+	(void)(var);			\
+	migrate_enable();		\
+} while (0)
+
+#else
+
+#define get_local_var(var)	get_cpu_var(var)
+#define put_local_var(var)	put_cpu_var(var)
+#define get_local_ptr(var)	get_cpu_ptr(var)
+#define put_local_ptr(var)	put_cpu_ptr(var)
+
+#endif
+
 /* minimum unit size, also is the maximum supported allocation size */
 #define PCPU_MIN_UNIT_SIZE		PFN_ALIGN(32 << 10)
 
Index: linux-4.19.25-rt16/include/linux/pid.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/pid.h
+++ linux-4.19.25-rt16/include/linux/pid.h
@@ -3,6 +3,7 @@
 #define _LINUX_PID_H
 
 #include <linux/rculist.h>
+#include <linux/atomic.h>
 
 enum pid_type
 {
Index: linux-4.19.25-rt16/include/linux/posix-timers.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/posix-timers.h
+++ linux-4.19.25-rt16/include/linux/posix-timers.h
@@ -114,8 +114,8 @@ struct k_itimer {
 		struct {
 			struct alarm	alarmtimer;
 		} alarm;
-		struct rcu_head		rcu;
 	} it;
+	struct rcu_head		rcu;
 };
 
 void run_posix_cpu_timers(struct task_struct *task);
Index: linux-4.19.25-rt16/include/linux/preempt.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/preempt.h
+++ linux-4.19.25-rt16/include/linux/preempt.h
@@ -51,7 +51,11 @@
 #define HARDIRQ_OFFSET	(1UL << HARDIRQ_SHIFT)
 #define NMI_OFFSET	(1UL << NMI_SHIFT)
 
-#define SOFTIRQ_DISABLE_OFFSET	(2 * SOFTIRQ_OFFSET)
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define SOFTIRQ_DISABLE_OFFSET		(2 * SOFTIRQ_OFFSET)
+#else
+# define SOFTIRQ_DISABLE_OFFSET		(0)
+#endif
 
 /* We use the MSB mostly because its available */
 #define PREEMPT_NEED_RESCHED	0x80000000
@@ -81,9 +85,15 @@
 #include <asm/preempt.h>
 
 #define hardirq_count()	(preempt_count() & HARDIRQ_MASK)
-#define softirq_count()	(preempt_count() & SOFTIRQ_MASK)
 #define irq_count()	(preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
 				 | NMI_MASK))
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define softirq_count()	(preempt_count() & SOFTIRQ_MASK)
+# define in_serving_softirq()	(softirq_count() & SOFTIRQ_OFFSET)
+#else
+# define softirq_count()	((unsigned long)current->softirq_nestcnt)
+extern int in_serving_softirq(void);
+#endif
 
 /*
  * Are we doing bottom half or hardware interrupt processing?
@@ -101,7 +111,6 @@
 #define in_irq()		(hardirq_count())
 #define in_softirq()		(softirq_count())
 #define in_interrupt()		(irq_count())
-#define in_serving_softirq()	(softirq_count() & SOFTIRQ_OFFSET)
 #define in_nmi()		(preempt_count() & NMI_MASK)
 #define in_task()		(!(preempt_count() & \
 				   (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)))
@@ -118,7 +127,11 @@
 /*
  * The preempt_count offset after spin_lock()
  */
+#if !defined(CONFIG_PREEMPT_RT_FULL)
 #define PREEMPT_LOCK_OFFSET	PREEMPT_DISABLE_OFFSET
+#else
+#define PREEMPT_LOCK_OFFSET	0
+#endif
 
 /*
  * The preempt_count offset needed for things like:
@@ -167,6 +180,20 @@ extern void preempt_count_sub(int val);
 #define preempt_count_inc() preempt_count_add(1)
 #define preempt_count_dec() preempt_count_sub(1)
 
+#ifdef CONFIG_PREEMPT_LAZY
+#define add_preempt_lazy_count(val)	do { preempt_lazy_count() += (val); } while (0)
+#define sub_preempt_lazy_count(val)	do { preempt_lazy_count() -= (val); } while (0)
+#define inc_preempt_lazy_count()	add_preempt_lazy_count(1)
+#define dec_preempt_lazy_count()	sub_preempt_lazy_count(1)
+#define preempt_lazy_count()		(current_thread_info()->preempt_lazy_count)
+#else
+#define add_preempt_lazy_count(val)	do { } while (0)
+#define sub_preempt_lazy_count(val)	do { } while (0)
+#define inc_preempt_lazy_count()	do { } while (0)
+#define dec_preempt_lazy_count()	do { } while (0)
+#define preempt_lazy_count()		(0)
+#endif
+
 #ifdef CONFIG_PREEMPT_COUNT
 
 #define preempt_disable() \
@@ -175,16 +202,53 @@ do { \
 	barrier(); \
 } while (0)
 
+#define preempt_lazy_disable() \
+do { \
+	inc_preempt_lazy_count(); \
+	barrier(); \
+} while (0)
+
 #define sched_preempt_enable_no_resched() \
 do { \
 	barrier(); \
 	preempt_count_dec(); \
 } while (0)
 
-#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+# define preempt_check_resched_rt() preempt_check_resched()
+#else
+# define preempt_enable_no_resched() preempt_enable()
+# define preempt_check_resched_rt() barrier();
+#endif
 
 #define preemptible()	(preempt_count() == 0 && !irqs_disabled())
 
+#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+
+extern void migrate_disable(void);
+extern void migrate_enable(void);
+
+int __migrate_disabled(struct task_struct *p);
+
+#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+
+extern void migrate_disable(void);
+extern void migrate_enable(void);
+static inline int __migrate_disabled(struct task_struct *p)
+{
+	return 0;
+}
+
+#else
+#define migrate_disable()		preempt_disable()
+#define migrate_enable()		preempt_enable()
+static inline int __migrate_disabled(struct task_struct *p)
+{
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_PREEMPT
 #define preempt_enable() \
 do { \
@@ -206,6 +270,13 @@ do { \
 		__preempt_schedule(); \
 } while (0)
 
+#define preempt_lazy_enable() \
+do { \
+	dec_preempt_lazy_count(); \
+	barrier(); \
+	preempt_check_resched(); \
+} while (0)
+
 #else /* !CONFIG_PREEMPT */
 #define preempt_enable() \
 do { \
@@ -213,6 +284,12 @@ do { \
 	preempt_count_dec(); \
 } while (0)
 
+#define preempt_lazy_enable() \
+do { \
+	dec_preempt_lazy_count(); \
+	barrier(); \
+} while (0)
+
 #define preempt_enable_notrace() \
 do { \
 	barrier(); \
@@ -251,8 +328,16 @@ do { \
 #define preempt_disable_notrace()		barrier()
 #define preempt_enable_no_resched_notrace()	barrier()
 #define preempt_enable_notrace()		barrier()
+#define preempt_check_resched_rt()		barrier()
 #define preemptible()				0
 
+#define migrate_disable()			barrier()
+#define migrate_enable()			barrier()
+
+static inline int __migrate_disabled(struct task_struct *p)
+{
+	return 0;
+}
 #endif /* CONFIG_PREEMPT_COUNT */
 
 #ifdef MODULE
@@ -271,10 +356,22 @@ do { \
 } while (0)
 #define preempt_fold_need_resched() \
 do { \
-	if (tif_need_resched()) \
+	if (tif_need_resched_now()) \
 		set_preempt_need_resched(); \
 } while (0)
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define preempt_disable_rt()		preempt_disable()
+# define preempt_enable_rt()		preempt_enable()
+# define preempt_disable_nort()		barrier()
+# define preempt_enable_nort()		barrier()
+#else
+# define preempt_disable_rt()		barrier()
+# define preempt_enable_rt()		barrier()
+# define preempt_disable_nort()		preempt_disable()
+# define preempt_enable_nort()		preempt_enable()
+#endif
+
 #ifdef CONFIG_PREEMPT_NOTIFIERS
 
 struct preempt_notifier;
Index: linux-4.19.25-rt16/include/linux/printk.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/printk.h
+++ linux-4.19.25-rt16/include/linux/printk.h
@@ -140,9 +140,11 @@ struct va_format {
 #ifdef CONFIG_EARLY_PRINTK
 extern asmlinkage __printf(1, 2)
 void early_printk(const char *fmt, ...);
+extern void printk_kill(void);
 #else
 static inline __printf(1, 2) __cold
 void early_printk(const char *s, ...) { }
+static inline void printk_kill(void) { }
 #endif
 
 #ifdef CONFIG_PRINTK_NMI
Index: linux-4.19.25-rt16/include/linux/radix-tree.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/radix-tree.h
+++ linux-4.19.25-rt16/include/linux/radix-tree.h
@@ -330,6 +330,8 @@ unsigned int radix_tree_gang_lookup_slot
 int radix_tree_preload(gfp_t gfp_mask);
 int radix_tree_maybe_preload(gfp_t gfp_mask);
 int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order);
+void radix_tree_preload_end(void);
+
 void radix_tree_init(void);
 void *radix_tree_tag_set(struct radix_tree_root *,
 			unsigned long index, unsigned int tag);
@@ -349,11 +351,6 @@ unsigned int radix_tree_gang_lookup_tag_
 		unsigned int max_items, unsigned int tag);
 int radix_tree_tagged(const struct radix_tree_root *, unsigned int tag);
 
-static inline void radix_tree_preload_end(void)
-{
-	preempt_enable();
-}
-
 int radix_tree_split_preload(unsigned old_order, unsigned new_order, gfp_t);
 int radix_tree_split(struct radix_tree_root *, unsigned long index,
 			unsigned new_order);
Index: linux-4.19.25-rt16/include/linux/random.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/random.h
+++ linux-4.19.25-rt16/include/linux/random.h
@@ -32,7 +32,7 @@ static inline void add_latent_entropy(vo
 
 extern void add_input_randomness(unsigned int type, unsigned int code,
 				 unsigned int value) __latent_entropy;
-extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;
+extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip) __latent_entropy;
 
 extern void get_random_bytes(void *buf, int nbytes);
 extern int wait_for_random_bytes(void);
Index: linux-4.19.25-rt16/include/linux/rbtree.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/rbtree.h
+++ linux-4.19.25-rt16/include/linux/rbtree.h
@@ -31,7 +31,7 @@
 
 #include <linux/kernel.h>
 #include <linux/stddef.h>
-#include <linux/rcupdate.h>
+#include <linux/rcu_assign_pointer.h>
 
 struct rb_node {
 	unsigned long  __rb_parent_color;
Index: linux-4.19.25-rt16/include/linux/rcu_assign_pointer.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/rcu_assign_pointer.h
@@ -0,0 +1,54 @@
+#ifndef __LINUX_RCU_ASSIGN_POINTER_H__
+#define __LINUX_RCU_ASSIGN_POINTER_H__
+#include <linux/compiler.h>
+#include <asm/barrier.h>
+
+/**
+ * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
+ * @v: The value to statically initialize with.
+ */
+#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
+
+/**
+ * rcu_assign_pointer() - assign to RCU-protected pointer
+ * @p: pointer to assign to
+ * @v: value to assign (publish)
+ *
+ * Assigns the specified value to the specified RCU-protected
+ * pointer, ensuring that any concurrent RCU readers will see
+ * any prior initialization.
+ *
+ * Inserts memory barriers on architectures that require them
+ * (which is most of them), and also prevents the compiler from
+ * reordering the code that initializes the structure after the pointer
+ * assignment.  More importantly, this call documents which pointers
+ * will be dereferenced by RCU read-side code.
+ *
+ * In some special cases, you may use RCU_INIT_POINTER() instead
+ * of rcu_assign_pointer().  RCU_INIT_POINTER() is a bit faster due
+ * to the fact that it does not constrain either the CPU or the compiler.
+ * That said, using RCU_INIT_POINTER() when you should have used
+ * rcu_assign_pointer() is a very bad thing that results in
+ * impossible-to-diagnose memory corruption.  So please be careful.
+ * See the RCU_INIT_POINTER() comment header for details.
+ *
+ * Note that rcu_assign_pointer() evaluates each of its arguments only
+ * once, appearances notwithstanding.  One of the "extra" evaluations
+ * is in typeof() and the other visible only to sparse (__CHECKER__),
+ * neither of which actually execute the argument.  As with most cpp
+ * macros, this execute-arguments-only-once property is important, so
+ * please be careful when making changes to rcu_assign_pointer() and the
+ * other macros that it invokes.
+ */
+#define rcu_assign_pointer(p, v)					      \
+({									      \
+	uintptr_t _r_a_p__v = (uintptr_t)(v);				      \
+									      \
+	if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL)	      \
+		WRITE_ONCE((p), (typeof(p))(_r_a_p__v));		      \
+	else								      \
+		smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
+	_r_a_p__v;							      \
+})
+
+#endif
Index: linux-4.19.25-rt16/include/linux/rcupdate.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/rcupdate.h
+++ linux-4.19.25-rt16/include/linux/rcupdate.h
@@ -42,6 +42,7 @@
 #include <linux/lockdep.h>
 #include <asm/processor.h>
 #include <linux/cpumask.h>
+#include <linux/rcu_assign_pointer.h>
 
 #define ULONG_CMP_GE(a, b)	(ULONG_MAX / 2 >= (a) - (b))
 #define ULONG_CMP_LT(a, b)	(ULONG_MAX / 2 < (a) - (b))
@@ -55,7 +56,11 @@ void call_rcu(struct rcu_head *head, rcu
 #define	call_rcu	call_rcu_sched
 #endif /* #else #ifdef CONFIG_PREEMPT_RCU */
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+#define call_rcu_bh	call_rcu
+#else
 void call_rcu_bh(struct rcu_head *head, rcu_callback_t func);
+#endif
 void call_rcu_sched(struct rcu_head *head, rcu_callback_t func);
 void synchronize_sched(void);
 void rcu_barrier_tasks(void);
@@ -73,6 +78,11 @@ void synchronize_rcu(void);
  * types of kernel builds, the rcu_read_lock() nesting depth is unknowable.
  */
 #define rcu_preempt_depth() (current->rcu_read_lock_nesting)
+#ifndef CONFIG_PREEMPT_RT_FULL
+#define sched_rcu_preempt_depth()	rcu_preempt_depth()
+#else
+static inline int sched_rcu_preempt_depth(void) { return 0; }
+#endif
 
 #else /* #ifdef CONFIG_PREEMPT_RCU */
 
@@ -98,6 +108,8 @@ static inline int rcu_preempt_depth(void
 	return 0;
 }
 
+#define sched_rcu_preempt_depth()	rcu_preempt_depth()
+
 #endif /* #else #ifdef CONFIG_PREEMPT_RCU */
 
 /* Internal to kernel */
@@ -255,7 +267,14 @@ extern struct lockdep_map rcu_sched_lock
 extern struct lockdep_map rcu_callback_map;
 int debug_lockdep_rcu_enabled(void);
 int rcu_read_lock_held(void);
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline int rcu_read_lock_bh_held(void)
+{
+	return rcu_read_lock_held();
+}
+#else
 int rcu_read_lock_bh_held(void);
+#endif
 int rcu_read_lock_sched_held(void);
 
 #else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
@@ -365,54 +384,6 @@ static inline void rcu_preempt_sleep_che
 })
 
 /**
- * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
- * @v: The value to statically initialize with.
- */
-#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
-
-/**
- * rcu_assign_pointer() - assign to RCU-protected pointer
- * @p: pointer to assign to
- * @v: value to assign (publish)
- *
- * Assigns the specified value to the specified RCU-protected
- * pointer, ensuring that any concurrent RCU readers will see
- * any prior initialization.
- *
- * Inserts memory barriers on architectures that require them
- * (which is most of them), and also prevents the compiler from
- * reordering the code that initializes the structure after the pointer
- * assignment.  More importantly, this call documents which pointers
- * will be dereferenced by RCU read-side code.
- *
- * In some special cases, you may use RCU_INIT_POINTER() instead
- * of rcu_assign_pointer().  RCU_INIT_POINTER() is a bit faster due
- * to the fact that it does not constrain either the CPU or the compiler.
- * That said, using RCU_INIT_POINTER() when you should have used
- * rcu_assign_pointer() is a very bad thing that results in
- * impossible-to-diagnose memory corruption.  So please be careful.
- * See the RCU_INIT_POINTER() comment header for details.
- *
- * Note that rcu_assign_pointer() evaluates each of its arguments only
- * once, appearances notwithstanding.  One of the "extra" evaluations
- * is in typeof() and the other visible only to sparse (__CHECKER__),
- * neither of which actually execute the argument.  As with most cpp
- * macros, this execute-arguments-only-once property is important, so
- * please be careful when making changes to rcu_assign_pointer() and the
- * other macros that it invokes.
- */
-#define rcu_assign_pointer(p, v)					      \
-({									      \
-	uintptr_t _r_a_p__v = (uintptr_t)(v);				      \
-									      \
-	if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL)	      \
-		WRITE_ONCE((p), (typeof(p))(_r_a_p__v));		      \
-	else								      \
-		smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
-	_r_a_p__v;							      \
-})
-
-/**
  * rcu_swap_protected() - swap an RCU and a regular pointer
  * @rcu_ptr: RCU pointer
  * @ptr: regular pointer
@@ -703,10 +674,14 @@ static inline void rcu_read_unlock(void)
 static inline void rcu_read_lock_bh(void)
 {
 	local_bh_disable();
+#ifdef CONFIG_PREEMPT_RT_FULL
+	rcu_read_lock();
+#else
 	__acquire(RCU_BH);
 	rcu_lock_acquire(&rcu_bh_lock_map);
 	RCU_LOCKDEP_WARN(!rcu_is_watching(),
 			 "rcu_read_lock_bh() used illegally while idle");
+#endif
 }
 
 /*
@@ -716,10 +691,14 @@ static inline void rcu_read_lock_bh(void
  */
 static inline void rcu_read_unlock_bh(void)
 {
+#ifdef CONFIG_PREEMPT_RT_FULL
+	rcu_read_unlock();
+#else
 	RCU_LOCKDEP_WARN(!rcu_is_watching(),
 			 "rcu_read_unlock_bh() used illegally while idle");
 	rcu_lock_release(&rcu_bh_lock_map);
 	__release(RCU_BH);
+#endif
 	local_bh_enable();
 }
 
Index: linux-4.19.25-rt16/include/linux/rcutree.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/rcutree.h
+++ linux-4.19.25-rt16/include/linux/rcutree.h
@@ -44,7 +44,11 @@ static inline void rcu_virt_note_context
 	rcu_note_context_switch(false);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define synchronize_rcu_bh	synchronize_rcu
+#else
 void synchronize_rcu_bh(void);
+#endif
 void synchronize_sched_expedited(void);
 void synchronize_rcu_expedited(void);
 
@@ -72,7 +76,11 @@ static inline void synchronize_rcu_bh_ex
 }
 
 void rcu_barrier(void);
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define rcu_barrier_bh		rcu_barrier
+#else
 void rcu_barrier_bh(void);
+#endif
 void rcu_barrier_sched(void);
 bool rcu_eqs_special_set(int cpu);
 unsigned long get_state_synchronize_rcu(void);
Index: linux-4.19.25-rt16/include/linux/rtmutex.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/rtmutex.h
+++ linux-4.19.25-rt16/include/linux/rtmutex.h
@@ -14,11 +14,15 @@
 #define __LINUX_RT_MUTEX_H
 
 #include <linux/linkage.h>
+#include <linux/spinlock_types_raw.h>
 #include <linux/rbtree.h>
-#include <linux/spinlock_types.h>
 
 extern int max_lock_depth; /* for sysctl */
 
+#ifdef CONFIG_DEBUG_MUTEXES
+#include <linux/debug_locks.h>
+#endif
+
 /**
  * The rt_mutex structure
  *
@@ -31,8 +35,8 @@ struct rt_mutex {
 	raw_spinlock_t		wait_lock;
 	struct rb_root_cached   waiters;
 	struct task_struct	*owner;
-#ifdef CONFIG_DEBUG_RT_MUTEXES
 	int			save_state;
+#ifdef CONFIG_DEBUG_RT_MUTEXES
 	const char		*name, *file;
 	int			line;
 	void			*magic;
@@ -82,16 +86,23 @@ do { \
 #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
 #endif
 
-#define __RT_MUTEX_INITIALIZER(mutexname) \
-	{ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
+#define __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \
+	.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
 	, .waiters = RB_ROOT_CACHED \
 	, .owner = NULL \
 	__DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
-	__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)}
+	__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
+
+#define __RT_MUTEX_INITIALIZER(mutexname) \
+	{ __RT_MUTEX_INITIALIZER_PLAIN(mutexname) }
 
 #define DEFINE_RT_MUTEX(mutexname) \
 	struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
 
+#define __RT_MUTEX_INITIALIZER_SAVE_STATE(mutexname) \
+	{ __RT_MUTEX_INITIALIZER_PLAIN(mutexname)    \
+		, .save_state = 1 }
+
 /**
  * rt_mutex_is_locked - is the mutex locked
  * @lock: the mutex to be queried
@@ -115,6 +126,7 @@ extern void rt_mutex_lock(struct rt_mute
 #endif
 
 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
 extern int rt_mutex_timed_lock(struct rt_mutex *lock,
 			       struct hrtimer_sleeper *timeout);
 
Index: linux-4.19.25-rt16/include/linux/rwlock_rt.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/rwlock_rt.h
@@ -0,0 +1,119 @@
+#ifndef __LINUX_RWLOCK_RT_H
+#define __LINUX_RWLOCK_RT_H
+
+#ifndef __LINUX_SPINLOCK_H
+#error Do not include directly. Use spinlock.h
+#endif
+
+extern void __lockfunc rt_write_lock(rwlock_t *rwlock);
+extern void __lockfunc rt_read_lock(rwlock_t *rwlock);
+extern int __lockfunc rt_write_trylock(rwlock_t *rwlock);
+extern int __lockfunc rt_read_trylock(rwlock_t *rwlock);
+extern void __lockfunc rt_write_unlock(rwlock_t *rwlock);
+extern void __lockfunc rt_read_unlock(rwlock_t *rwlock);
+extern int __lockfunc rt_read_can_lock(rwlock_t *rwlock);
+extern int __lockfunc rt_write_can_lock(rwlock_t *rwlock);
+extern void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key);
+
+#define read_can_lock(rwlock)		rt_read_can_lock(rwlock)
+#define write_can_lock(rwlock)		rt_write_can_lock(rwlock)
+
+#define read_trylock(lock)	__cond_lock(lock, rt_read_trylock(lock))
+#define write_trylock(lock)	__cond_lock(lock, rt_write_trylock(lock))
+
+static inline int __write_trylock_rt_irqsave(rwlock_t *lock, unsigned long *flags)
+{
+	/* XXX ARCH_IRQ_ENABLED */
+	*flags = 0;
+	return rt_write_trylock(lock);
+}
+
+#define write_trylock_irqsave(lock, flags)		\
+	__cond_lock(lock, __write_trylock_rt_irqsave(lock, &(flags)))
+
+#define read_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		rt_read_lock(lock);			\
+		flags = 0;				\
+	} while (0)
+
+#define write_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		rt_write_lock(lock);			\
+		flags = 0;				\
+	} while (0)
+
+#define read_lock(lock)		rt_read_lock(lock)
+
+#define read_lock_bh(lock)				\
+	do {						\
+		local_bh_disable();			\
+		rt_read_lock(lock);			\
+	} while (0)
+
+#define read_lock_irq(lock)	read_lock(lock)
+
+#define write_lock(lock)	rt_write_lock(lock)
+
+#define write_lock_bh(lock)				\
+	do {						\
+		local_bh_disable();			\
+		rt_write_lock(lock);			\
+	} while (0)
+
+#define write_lock_irq(lock)	write_lock(lock)
+
+#define read_unlock(lock)	rt_read_unlock(lock)
+
+#define read_unlock_bh(lock)				\
+	do {						\
+		rt_read_unlock(lock);			\
+		local_bh_enable();			\
+	} while (0)
+
+#define read_unlock_irq(lock)	read_unlock(lock)
+
+#define write_unlock(lock)	rt_write_unlock(lock)
+
+#define write_unlock_bh(lock)				\
+	do {						\
+		rt_write_unlock(lock);			\
+		local_bh_enable();			\
+	} while (0)
+
+#define write_unlock_irq(lock)	write_unlock(lock)
+
+#define read_unlock_irqrestore(lock, flags)		\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		(void) flags;				\
+		rt_read_unlock(lock);			\
+	} while (0)
+
+#define write_unlock_irqrestore(lock, flags) \
+	do {						\
+		typecheck(unsigned long, flags);	\
+		(void) flags;				\
+		rt_write_unlock(lock);			\
+	} while (0)
+
+#define rwlock_init(rwl)				\
+do {							\
+	static struct lock_class_key __key;		\
+							\
+	__rt_rwlock_init(rwl, #rwl, &__key);		\
+} while (0)
+
+/*
+ * Internal functions made global for CPU pinning
+ */
+void __read_rt_lock(struct rt_rw_lock *lock);
+int __read_rt_trylock(struct rt_rw_lock *lock);
+void __write_rt_lock(struct rt_rw_lock *lock);
+int __write_rt_trylock(struct rt_rw_lock *lock);
+void __read_rt_unlock(struct rt_rw_lock *lock);
+void __write_rt_unlock(struct rt_rw_lock *lock);
+
+#endif
Index: linux-4.19.25-rt16/include/linux/rwlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/rwlock_types.h
+++ linux-4.19.25-rt16/include/linux/rwlock_types.h
@@ -1,6 +1,10 @@
 #ifndef __LINUX_RWLOCK_TYPES_H
 #define __LINUX_RWLOCK_TYPES_H
 
+#if !defined(__LINUX_SPINLOCK_TYPES_H)
+# error "Do not include directly, include spinlock_types.h"
+#endif
+
 /*
  * include/linux/rwlock_types.h - generic rwlock type definitions
  *				  and initializers
Index: linux-4.19.25-rt16/include/linux/rwlock_types_rt.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/rwlock_types_rt.h
@@ -0,0 +1,55 @@
+#ifndef __LINUX_RWLOCK_TYPES_RT_H
+#define __LINUX_RWLOCK_TYPES_RT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define RW_DEP_MAP_INIT(lockname)	.dep_map = { .name = #lockname }
+#else
+# define RW_DEP_MAP_INIT(lockname)
+#endif
+
+typedef struct rt_rw_lock rwlock_t;
+
+#define __RW_LOCK_UNLOCKED(name) __RWLOCK_RT_INITIALIZER(name)
+
+#define DEFINE_RWLOCK(name) \
+	rwlock_t name = __RW_LOCK_UNLOCKED(name)
+
+/*
+ * A reader biased implementation primarily for CPU pinning.
+ *
+ * Can be selected as general replacement for the single reader RT rwlock
+ * variant
+ */
+struct rt_rw_lock {
+	struct rt_mutex		rtmutex;
+	atomic_t		readers;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+};
+
+#define READER_BIAS	(1U << 31)
+#define WRITER_BIAS	(1U << 30)
+
+#define __RWLOCK_RT_INITIALIZER(name)					\
+{									\
+	.readers = ATOMIC_INIT(READER_BIAS),				\
+	.rtmutex = __RT_MUTEX_INITIALIZER_SAVE_STATE(name.rtmutex),	\
+	RW_DEP_MAP_INIT(name)						\
+}
+
+void __rwlock_biased_rt_init(struct rt_rw_lock *lock, const char *name,
+			     struct lock_class_key *key);
+
+#define rwlock_biased_rt_init(rwlock)					\
+	do {								\
+		static struct lock_class_key __key;			\
+									\
+		__rwlock_biased_rt_init((rwlock), #rwlock, &__key);	\
+	} while (0)
+
+#endif
Index: linux-4.19.25-rt16/include/linux/rwsem.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/rwsem.h
+++ linux-4.19.25-rt16/include/linux/rwsem.h
@@ -20,6 +20,10 @@
 #include <linux/osq_lock.h>
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+#include <linux/rwsem_rt.h>
+#else /* PREEMPT_RT_FULL */
+
 struct rw_semaphore;
 
 #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
@@ -114,6 +118,13 @@ static inline int rwsem_is_contended(str
 	return !list_empty(&sem->wait_list);
 }
 
+#endif /* !PREEMPT_RT_FULL */
+
+/*
+ * The functions below are the same for all rwsem implementations including
+ * the RT specific variant.
+ */
+
 /*
  * lock for reading
  */
Index: linux-4.19.25-rt16/include/linux/rwsem_rt.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/rwsem_rt.h
@@ -0,0 +1,68 @@
+#ifndef _LINUX_RWSEM_RT_H
+#define _LINUX_RWSEM_RT_H
+
+#ifndef _LINUX_RWSEM_H
+#error "Include rwsem.h"
+#endif
+
+#include <linux/rtmutex.h>
+#include <linux/swait.h>
+
+#define READER_BIAS		(1U << 31)
+#define WRITER_BIAS		(1U << 30)
+
+struct rw_semaphore {
+	atomic_t		readers;
+	struct rt_mutex		rtmutex;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+};
+
+#define __RWSEM_INITIALIZER(name)				\
+{								\
+	.readers = ATOMIC_INIT(READER_BIAS),			\
+	.rtmutex = __RT_MUTEX_INITIALIZER(name.rtmutex),	\
+	RW_DEP_MAP_INIT(name)					\
+}
+
+#define DECLARE_RWSEM(lockname) \
+	struct rw_semaphore lockname = __RWSEM_INITIALIZER(lockname)
+
+extern void  __rwsem_init(struct rw_semaphore *rwsem, const char *name,
+			  struct lock_class_key *key);
+
+#define __init_rwsem(sem, name, key)			\
+do {							\
+		rt_mutex_init(&(sem)->rtmutex);		\
+		__rwsem_init((sem), (name), (key));	\
+} while (0)
+
+#define init_rwsem(sem)					\
+do {							\
+	static struct lock_class_key __key;		\
+							\
+	__init_rwsem((sem), #sem, &__key);		\
+} while (0)
+
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return atomic_read(&sem->readers) != READER_BIAS;
+}
+
+static inline int rwsem_is_contended(struct rw_semaphore *sem)
+{
+	return atomic_read(&sem->readers) > 0;
+}
+
+extern void __down_read(struct rw_semaphore *sem);
+extern int __down_read_killable(struct rw_semaphore *sem);
+extern int __down_read_trylock(struct rw_semaphore *sem);
+extern void __down_write(struct rw_semaphore *sem);
+extern int __must_check __down_write_killable(struct rw_semaphore *sem);
+extern int __down_write_trylock(struct rw_semaphore *sem);
+extern void __up_read(struct rw_semaphore *sem);
+extern void __up_write(struct rw_semaphore *sem);
+extern void __downgrade_write(struct rw_semaphore *sem);
+
+#endif
Index: linux-4.19.25-rt16/include/linux/sched.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/sched.h
+++ linux-4.19.25-rt16/include/linux/sched.h
@@ -28,6 +28,7 @@
 #include <linux/mm_types_task.h>
 #include <linux/task_io_accounting.h>
 #include <linux/rseq.h>
+#include <asm/kmap_types.h>
 
 /* task_struct member predeclarations (sorted alphabetically): */
 struct audit_context;
@@ -101,12 +102,8 @@ struct task_group;
 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
 					 TASK_PARKED)
 
-#define task_is_traced(task)		((task->state & __TASK_TRACED) != 0)
-
 #define task_is_stopped(task)		((task->state & __TASK_STOPPED) != 0)
 
-#define task_is_stopped_or_traced(task)	((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
-
 #define task_contributes_to_load(task)	((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
 					 (task->flags & PF_FROZEN) == 0 && \
 					 (task->state & TASK_NOLOAD) == 0)
@@ -134,6 +131,9 @@ struct task_group;
 		smp_store_mb(current->state, (state_value));	\
 	} while (0)
 
+#define __set_current_state_no_track(state_value)		\
+	current->state = (state_value);
+
 #define set_special_state(state_value)					\
 	do {								\
 		unsigned long flags; /* may shadow */			\
@@ -143,6 +143,7 @@ struct task_group;
 		current->state = (state_value);				\
 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
 	} while (0)
+
 #else
 /*
  * set_current_state() includes a barrier so that the write of current->state
@@ -187,6 +188,9 @@ struct task_group;
 #define set_current_state(state_value)					\
 	smp_store_mb(current->state, (state_value))
 
+#define __set_current_state_no_track(state_value)	\
+	__set_current_state(state_value)
+
 /*
  * set_special_state() should be used for those states when the blocking task
  * can not use the regular condition based wait-loop. In that case we must
@@ -600,6 +604,8 @@ struct task_struct {
 #endif
 	/* -1 unrunnable, 0 runnable, >0 stopped: */
 	volatile long			state;
+	/* saved state for "spinlock sleepers" */
+	volatile long			saved_state;
 
 	/*
 	 * This begins the randomizable portion of task_struct. Only
@@ -660,7 +666,25 @@ struct task_struct {
 
 	unsigned int			policy;
 	int				nr_cpus_allowed;
-	cpumask_t			cpus_allowed;
+	const cpumask_t			*cpus_ptr;
+	cpumask_t			cpus_mask;
+#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+	int				migrate_disable;
+	int				migrate_disable_update;
+	int				pinned_on_cpu;
+# ifdef CONFIG_SCHED_DEBUG
+	int				migrate_disable_atomic;
+# endif
+
+#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+# ifdef CONFIG_SCHED_DEBUG
+	int				migrate_disable;
+	int				migrate_disable_atomic;
+# endif
+#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+	int				sleeping_lock;
+#endif
 
 #ifdef CONFIG_PREEMPT_RCU
 	int				rcu_read_lock_nesting;
@@ -824,6 +848,9 @@ struct task_struct {
 #ifdef CONFIG_POSIX_TIMERS
 	struct task_cputime		cputime_expires;
 	struct list_head		cpu_timers[3];
+#ifdef CONFIG_PREEMPT_RT_BASE
+	struct task_struct		*posix_timer_list;
+#endif
 #endif
 
 	/* Process credentials: */
@@ -868,11 +895,17 @@ struct task_struct {
 	/* Signal handlers: */
 	struct signal_struct		*signal;
 	struct sighand_struct		*sighand;
+	struct sigqueue			*sigqueue_cache;
+
 	sigset_t			blocked;
 	sigset_t			real_blocked;
 	/* Restored if set_restore_sigmask() was used: */
 	sigset_t			saved_sigmask;
 	struct sigpending		pending;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	/* TODO: move me into ->restart_block ? */
+	struct				siginfo forced_info;
+#endif
 	unsigned long			sas_ss_sp;
 	size_t				sas_ss_size;
 	unsigned int			sas_ss_flags;
@@ -897,6 +930,7 @@ struct task_struct {
 	raw_spinlock_t			pi_lock;
 
 	struct wake_q_node		wake_q;
+	struct wake_q_node		wake_q_sleeper;
 
 #ifdef CONFIG_RT_MUTEXES
 	/* PI waiters blocked on a rt_mutex held by this task: */
@@ -1171,9 +1205,23 @@ struct task_struct {
 	unsigned int			sequential_io;
 	unsigned int			sequential_io_avg;
 #endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+	struct rcu_head			put_rcu;
+	int				softirq_nestcnt;
+	unsigned int			softirqs_raised;
+#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+# if defined CONFIG_HIGHMEM || defined CONFIG_X86_32
+	int				kmap_idx;
+	pte_t				kmap_pte[KM_TYPE_NR];
+# endif
+#endif
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 	unsigned long			task_state_change;
 #endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+	int				xmit_recursion;
+#endif
 	int				pagefault_disabled;
 #ifdef CONFIG_MMU
 	struct task_struct		*oom_reaper_list;
@@ -1367,6 +1415,7 @@ extern struct pid *cad_pid;
 /*
  * Per process flags
  */
+#define PF_IN_SOFTIRQ		0x00000001      /* Task is serving softirq */
 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
 #define PF_EXITING		0x00000004	/* Getting shut down */
 #define PF_EXITPIDONE		0x00000008	/* PI exit done on shut down */
@@ -1390,7 +1439,7 @@ extern struct pid *cad_pid;
 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
 #define PF_SWAPWRITE		0x00800000	/* Allowed to write to swap */
-#define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_allowed */
+#define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
 #define PF_MUTEX_TESTER		0x20000000	/* Thread belongs to the rt mutex tester */
 #define PF_FREEZER_SKIP		0x40000000	/* Freezer should not count it as freezable */
@@ -1595,6 +1644,7 @@ extern struct task_struct *find_get_task
 
 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
 extern int wake_up_process(struct task_struct *tsk);
+extern int wake_up_lock_sleeper(struct task_struct *tsk);
 extern void wake_up_new_task(struct task_struct *tsk);
 
 #ifdef CONFIG_SMP
@@ -1677,6 +1727,89 @@ static inline int test_tsk_need_resched(
 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
 }
 
+#ifdef CONFIG_PREEMPT_LAZY
+static inline void set_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int test_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY));
+}
+
+static inline int need_resched_lazy(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int need_resched_now(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+#else
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk) { }
+static inline int need_resched_lazy(void) { return 0; }
+
+static inline int need_resched_now(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+#endif
+
+
+static inline bool __task_is_stopped_or_traced(struct task_struct *task)
+{
+	if (task->state & (__TASK_STOPPED | __TASK_TRACED))
+		return true;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (task->saved_state & (__TASK_STOPPED | __TASK_TRACED))
+		return true;
+#endif
+	return false;
+}
+
+static inline bool task_is_stopped_or_traced(struct task_struct *task)
+{
+	bool traced_stopped;
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&task->pi_lock, flags);
+	traced_stopped = __task_is_stopped_or_traced(task);
+	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+#else
+	traced_stopped = __task_is_stopped_or_traced(task);
+#endif
+	return traced_stopped;
+}
+
+static inline bool task_is_traced(struct task_struct *task)
+{
+	bool traced = false;
+
+	if (task->state & __TASK_TRACED)
+		return true;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	/* in case the task is sleeping on tasklist_lock */
+	raw_spin_lock_irq(&task->pi_lock);
+	if (task->state & __TASK_TRACED)
+		traced = true;
+	else if (task->saved_state & __TASK_TRACED)
+		traced = true;
+	raw_spin_unlock_irq(&task->pi_lock);
+#endif
+	return traced;
+}
+
 /*
  * cond_resched() and cond_resched_lock(): latency reduction via
  * explicit rescheduling in places that are safe. The return
@@ -1729,6 +1862,23 @@ static __always_inline bool need_resched
 	return unlikely(tif_need_resched());
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline void sleeping_lock_inc(void)
+{
+	current->sleeping_lock++;
+}
+
+static inline void sleeping_lock_dec(void)
+{
+	current->sleeping_lock--;
+}
+
+#else
+
+static inline void sleeping_lock_inc(void) { }
+static inline void sleeping_lock_dec(void) { }
+#endif
+
 /*
  * Wrappers for p->thread_info->cpu access. No-op on UP.
  */
Index: linux-4.19.25-rt16/include/linux/sched/mm.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/sched/mm.h
+++ linux-4.19.25-rt16/include/linux/sched/mm.h
@@ -49,6 +49,17 @@ static inline void mmdrop(struct mm_stru
 		__mmdrop(mm);
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+extern void __mmdrop_delayed(struct rcu_head *rhp);
+static inline void mmdrop_delayed(struct mm_struct *mm)
+{
+	if (atomic_dec_and_test(&mm->mm_count))
+		call_rcu(&mm->delayed_drop, __mmdrop_delayed);
+}
+#else
+# define mmdrop_delayed(mm)	mmdrop(mm)
+#endif
+
 /*
  * This has to be called after a get_task_mm()/mmget_not_zero()
  * followed by taking the mmap_sem for writing before modifying the
Index: linux-4.19.25-rt16/include/linux/sched/task.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/sched/task.h
+++ linux-4.19.25-rt16/include/linux/sched/task.h
@@ -88,6 +88,15 @@ extern void sched_exec(void);
 
 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+extern void __put_task_struct_cb(struct rcu_head *rhp);
+
+static inline void put_task_struct(struct task_struct *t)
+{
+	if (atomic_dec_and_test(&t->usage))
+		call_rcu(&t->put_rcu, __put_task_struct_cb);
+}
+#else
 extern void __put_task_struct(struct task_struct *t);
 
 static inline void put_task_struct(struct task_struct *t)
@@ -95,7 +104,7 @@ static inline void put_task_struct(struc
 	if (atomic_dec_and_test(&t->usage))
 		__put_task_struct(t);
 }
-
+#endif
 struct task_struct *task_rcu_dereference(struct task_struct **ptask);
 
 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
Index: linux-4.19.25-rt16/include/linux/sched/wake_q.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/sched/wake_q.h
+++ linux-4.19.25-rt16/include/linux/sched/wake_q.h
@@ -47,8 +47,29 @@ static inline void wake_q_init(struct wa
 	head->lastp = &head->first;
 }
 
-extern void wake_q_add(struct wake_q_head *head,
-		       struct task_struct *task);
-extern void wake_up_q(struct wake_q_head *head);
+extern void __wake_q_add(struct wake_q_head *head,
+			 struct task_struct *task, bool sleeper);
+static inline void wake_q_add(struct wake_q_head *head,
+			      struct task_struct *task)
+{
+	__wake_q_add(head, task, false);
+}
+
+static inline void wake_q_add_sleeper(struct wake_q_head *head,
+				      struct task_struct *task)
+{
+	__wake_q_add(head, task, true);
+}
+
+extern void __wake_up_q(struct wake_q_head *head, bool sleeper);
+static inline void wake_up_q(struct wake_q_head *head)
+{
+	__wake_up_q(head, false);
+}
+
+static inline void wake_up_q_sleeper(struct wake_q_head *head)
+{
+	__wake_up_q(head, true);
+}
 
 #endif /* _LINUX_SCHED_WAKE_Q_H */
Index: linux-4.19.25-rt16/include/linux/seqlock.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/seqlock.h
+++ linux-4.19.25-rt16/include/linux/seqlock.h
@@ -221,20 +221,30 @@ static inline int read_seqcount_retry(co
 	return __read_seqcount_retry(s, start);
 }
 
-
-
-static inline void raw_write_seqcount_begin(seqcount_t *s)
+static inline void __raw_write_seqcount_begin(seqcount_t *s)
 {
 	s->sequence++;
 	smp_wmb();
 }
 
-static inline void raw_write_seqcount_end(seqcount_t *s)
+static inline void raw_write_seqcount_begin(seqcount_t *s)
+{
+	preempt_disable_rt();
+	__raw_write_seqcount_begin(s);
+}
+
+static inline void __raw_write_seqcount_end(seqcount_t *s)
 {
 	smp_wmb();
 	s->sequence++;
 }
 
+static inline void raw_write_seqcount_end(seqcount_t *s)
+{
+	__raw_write_seqcount_end(s);
+	preempt_enable_rt();
+}
+
 /**
  * raw_write_seqcount_barrier - do a seq write barrier
  * @s: pointer to seqcount_t
@@ -428,10 +438,33 @@ typedef struct {
 /*
  * Read side functions for starting and finalizing a read side section.
  */
+#ifndef CONFIG_PREEMPT_RT_FULL
 static inline unsigned read_seqbegin(const seqlock_t *sl)
 {
 	return read_seqcount_begin(&sl->seqcount);
 }
+#else
+/*
+ * Starvation safe read side for RT
+ */
+static inline unsigned read_seqbegin(seqlock_t *sl)
+{
+	unsigned ret;
+
+repeat:
+	ret = READ_ONCE(sl->seqcount.sequence);
+	if (unlikely(ret & 1)) {
+		/*
+		 * Take the lock and let the writer proceed (i.e. evtl
+		 * boost it), otherwise we could loop here forever.
+		 */
+		spin_unlock_wait(&sl->lock);
+		goto repeat;
+	}
+	smp_rmb();
+	return ret;
+}
+#endif
 
 static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start)
 {
@@ -446,36 +479,45 @@ static inline unsigned read_seqretry(con
 static inline void write_seqlock(seqlock_t *sl)
 {
 	spin_lock(&sl->lock);
-	write_seqcount_begin(&sl->seqcount);
+	__raw_write_seqcount_begin(&sl->seqcount);
+}
+
+static inline int try_write_seqlock(seqlock_t *sl)
+{
+	if (spin_trylock(&sl->lock)) {
+		__raw_write_seqcount_begin(&sl->seqcount);
+		return 1;
+	}
+	return 0;
 }
 
 static inline void write_sequnlock(seqlock_t *sl)
 {
-	write_seqcount_end(&sl->seqcount);
+	__raw_write_seqcount_end(&sl->seqcount);
 	spin_unlock(&sl->lock);
 }
 
 static inline void write_seqlock_bh(seqlock_t *sl)
 {
 	spin_lock_bh(&sl->lock);
-	write_seqcount_begin(&sl->seqcount);
+	__raw_write_seqcount_begin(&sl->seqcount);
 }
 
 static inline void write_sequnlock_bh(seqlock_t *sl)
 {
-	write_seqcount_end(&sl->seqcount);
+	__raw_write_seqcount_end(&sl->seqcount);
 	spin_unlock_bh(&sl->lock);
 }
 
 static inline void write_seqlock_irq(seqlock_t *sl)
 {
 	spin_lock_irq(&sl->lock);
-	write_seqcount_begin(&sl->seqcount);
+	__raw_write_seqcount_begin(&sl->seqcount);
 }
 
 static inline void write_sequnlock_irq(seqlock_t *sl)
 {
-	write_seqcount_end(&sl->seqcount);
+	__raw_write_seqcount_end(&sl->seqcount);
 	spin_unlock_irq(&sl->lock);
 }
 
@@ -484,7 +526,7 @@ static inline unsigned long __write_seql
 	unsigned long flags;
 
 	spin_lock_irqsave(&sl->lock, flags);
-	write_seqcount_begin(&sl->seqcount);
+	__raw_write_seqcount_begin(&sl->seqcount);
 	return flags;
 }
 
@@ -494,7 +536,7 @@ static inline unsigned long __write_seql
 static inline void
 write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags)
 {
-	write_seqcount_end(&sl->seqcount);
+	__raw_write_seqcount_end(&sl->seqcount);
 	spin_unlock_irqrestore(&sl->lock, flags);
 }
 
Index: linux-4.19.25-rt16/include/linux/signal.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/signal.h
+++ linux-4.19.25-rt16/include/linux/signal.h
@@ -245,6 +245,7 @@ static inline void init_sigpending(struc
 }
 
 extern void flush_sigqueue(struct sigpending *queue);
+extern void flush_task_sigqueue(struct task_struct *tsk);
 
 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
 static inline int valid_signal(unsigned long sig)
Index: linux-4.19.25-rt16/include/linux/skbuff.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/skbuff.h
+++ linux-4.19.25-rt16/include/linux/skbuff.h
@@ -287,6 +287,7 @@ struct sk_buff_head {
 
 	__u32		qlen;
 	spinlock_t	lock;
+	raw_spinlock_t	raw_lock;
 };
 
 struct sk_buff;
@@ -1702,6 +1703,12 @@ static inline void skb_queue_head_init(s
 	__skb_queue_head_init(list);
 }
 
+static inline void skb_queue_head_init_raw(struct sk_buff_head *list)
+{
+	raw_spin_lock_init(&list->raw_lock);
+	__skb_queue_head_init(list);
+}
+
 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
 		struct lock_class_key *class)
 {
Index: linux-4.19.25-rt16/include/linux/smp.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/smp.h
+++ linux-4.19.25-rt16/include/linux/smp.h
@@ -202,6 +202,9 @@ static inline int get_boot_cpu_id(void)
 #define get_cpu()		({ preempt_disable(); smp_processor_id(); })
 #define put_cpu()		preempt_enable()
 
+#define get_cpu_light()		({ migrate_disable(); smp_processor_id(); })
+#define put_cpu_light()		migrate_enable()
+
 /*
  * Callback to arch code if there's nosmp or maxcpus=0 on the
  * boot command line:
Index: linux-4.19.25-rt16/include/linux/spinlock.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/spinlock.h
+++ linux-4.19.25-rt16/include/linux/spinlock.h
@@ -298,7 +298,11 @@ static inline void do_raw_spin_unlock(ra
 })
 
 /* Include rwlock functions */
-#include <linux/rwlock.h>
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/rwlock_rt.h>
+#else
+# include <linux/rwlock.h>
+#endif
 
 /*
  * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
@@ -309,6 +313,10 @@ static inline void do_raw_spin_unlock(ra
 # include <linux/spinlock_api_up.h>
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/spinlock_rt.h>
+#else /* PREEMPT_RT_FULL */
+
 /*
  * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
  */
@@ -429,6 +437,8 @@ static __always_inline int spin_is_conte
 
 #define assert_spin_locked(lock)	assert_raw_spin_locked(&(lock)->rlock)
 
+#endif /* !PREEMPT_RT_FULL */
+
 /*
  * Pull the atomic_t declaration:
  * (asm-mips/atomic.h needs above definitions)
Index: linux-4.19.25-rt16/include/linux/spinlock_api_smp.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/spinlock_api_smp.h
+++ linux-4.19.25-rt16/include/linux/spinlock_api_smp.h
@@ -187,6 +187,8 @@ static inline int __raw_spin_trylock_bh(
 	return 0;
 }
 
-#include <linux/rwlock_api_smp.h>
+#ifndef CONFIG_PREEMPT_RT_FULL
+# include <linux/rwlock_api_smp.h>
+#endif
 
 #endif /* __LINUX_SPINLOCK_API_SMP_H */
Index: linux-4.19.25-rt16/include/linux/spinlock_rt.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/spinlock_rt.h
@@ -0,0 +1,156 @@
+#ifndef __LINUX_SPINLOCK_RT_H
+#define __LINUX_SPINLOCK_RT_H
+
+#ifndef __LINUX_SPINLOCK_H
+#error Do not include directly. Use spinlock.h
+#endif
+
+#include <linux/bug.h>
+
+extern void
+__rt_spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key);
+
+#define spin_lock_init(slock)				\
+do {							\
+	static struct lock_class_key __key;		\
+							\
+	rt_mutex_init(&(slock)->lock);			\
+	__rt_spin_lock_init(slock, #slock, &__key);	\
+} while (0)
+
+extern void __lockfunc rt_spin_lock(spinlock_t *lock);
+extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock);
+extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass);
+extern void __lockfunc rt_spin_unlock(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags);
+extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock(spinlock_t *lock);
+extern int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock);
+
+/*
+ * lockdep-less calls, for derived types like rwlock:
+ * (for trylock they can use rt_mutex_trylock() directly.
+ * Migrate disable handling must be done at the call site.
+ */
+extern void __lockfunc __rt_spin_lock(struct rt_mutex *lock);
+extern void __lockfunc __rt_spin_trylock(struct rt_mutex *lock);
+extern void __lockfunc __rt_spin_unlock(struct rt_mutex *lock);
+
+#define spin_lock(lock)			rt_spin_lock(lock)
+
+#define spin_lock_bh(lock)			\
+	do {					\
+		local_bh_disable();		\
+		rt_spin_lock(lock);		\
+	} while (0)
+
+#define spin_lock_irq(lock)		spin_lock(lock)
+
+#define spin_do_trylock(lock)		__cond_lock(lock, rt_spin_trylock(lock))
+
+#define spin_trylock(lock)			\
+({						\
+	int __locked;				\
+	__locked = spin_do_trylock(lock);	\
+	__locked;				\
+})
+
+#ifdef CONFIG_LOCKDEP
+# define spin_lock_nested(lock, subclass)		\
+	do {						\
+		rt_spin_lock_nested(lock, subclass);	\
+	} while (0)
+
+#define spin_lock_bh_nested(lock, subclass)		\
+	do {						\
+		local_bh_disable();			\
+		rt_spin_lock_nested(lock, subclass);	\
+	} while (0)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+	do {						 \
+		typecheck(unsigned long, flags);	 \
+		flags = 0;				 \
+		rt_spin_lock_nested(lock, subclass);	 \
+	} while (0)
+#else
+# define spin_lock_nested(lock, subclass)	spin_lock(lock)
+# define spin_lock_bh_nested(lock, subclass)	spin_lock_bh(lock)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+	do {						 \
+		typecheck(unsigned long, flags);	 \
+		flags = 0;				 \
+		spin_lock(lock);			 \
+	} while (0)
+#endif
+
+#define spin_lock_irqsave(lock, flags)			 \
+	do {						 \
+		typecheck(unsigned long, flags);	 \
+		flags = 0;				 \
+		spin_lock(lock);			 \
+	} while (0)
+
+static inline unsigned long spin_lock_trace_flags(spinlock_t *lock)
+{
+	unsigned long flags = 0;
+#ifdef CONFIG_TRACE_IRQFLAGS
+	flags = rt_spin_lock_trace_flags(lock);
+#else
+	spin_lock(lock); /* lock_local */
+#endif
+	return flags;
+}
+
+/* FIXME: we need rt_spin_lock_nest_lock */
+#define spin_lock_nest_lock(lock, nest_lock) spin_lock_nested(lock, 0)
+
+#define spin_unlock(lock)			rt_spin_unlock(lock)
+
+#define spin_unlock_bh(lock)				\
+	do {						\
+		rt_spin_unlock(lock);			\
+		local_bh_enable();			\
+	} while (0)
+
+#define spin_unlock_irq(lock)		spin_unlock(lock)
+
+#define spin_unlock_irqrestore(lock, flags)		\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		(void) flags;				\
+		spin_unlock(lock);			\
+	} while (0)
+
+#define spin_trylock_bh(lock)	__cond_lock(lock, rt_spin_trylock_bh(lock))
+#define spin_trylock_irq(lock)	spin_trylock(lock)
+
+#define spin_trylock_irqsave(lock, flags)	\
+	rt_spin_trylock_irqsave(lock, &(flags))
+
+#define spin_unlock_wait(lock)		rt_spin_unlock_wait(lock)
+
+#ifdef CONFIG_GENERIC_LOCKBREAK
+# define spin_is_contended(lock)	((lock)->break_lock)
+#else
+# define spin_is_contended(lock)	(((void)(lock), 0))
+#endif
+
+static inline int spin_can_lock(spinlock_t *lock)
+{
+	return !rt_mutex_is_locked(&lock->lock);
+}
+
+static inline int spin_is_locked(spinlock_t *lock)
+{
+	return rt_mutex_is_locked(&lock->lock);
+}
+
+static inline void assert_spin_locked(spinlock_t *lock)
+{
+	BUG_ON(!spin_is_locked(lock));
+}
+
+#endif
Index: linux-4.19.25-rt16/include/linux/spinlock_types.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/spinlock_types.h
+++ linux-4.19.25-rt16/include/linux/spinlock_types.h
@@ -9,77 +9,15 @@
  * Released under the General Public License (GPL).
  */
 
-#if defined(CONFIG_SMP)
-# include <asm/spinlock_types.h>
-#else
-# include <linux/spinlock_types_up.h>
-#endif
-
-#include <linux/lockdep.h>
-
-typedef struct raw_spinlock {
-	arch_spinlock_t raw_lock;
-#ifdef CONFIG_DEBUG_SPINLOCK
-	unsigned int magic, owner_cpu;
-	void *owner;
-#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-	struct lockdep_map dep_map;
-#endif
-} raw_spinlock_t;
-
-#define SPINLOCK_MAGIC		0xdead4ead
-
-#define SPINLOCK_OWNER_INIT	((void *)-1L)
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define SPIN_DEP_MAP_INIT(lockname)	.dep_map = { .name = #lockname }
-#else
-# define SPIN_DEP_MAP_INIT(lockname)
-#endif
+#include <linux/spinlock_types_raw.h>
 
-#ifdef CONFIG_DEBUG_SPINLOCK
-# define SPIN_DEBUG_INIT(lockname)		\
-	.magic = SPINLOCK_MAGIC,		\
-	.owner_cpu = -1,			\
-	.owner = SPINLOCK_OWNER_INIT,
+#ifndef CONFIG_PREEMPT_RT_FULL
+# include <linux/spinlock_types_nort.h>
+# include <linux/rwlock_types.h>
 #else
-# define SPIN_DEBUG_INIT(lockname)
+# include <linux/rtmutex.h>
+# include <linux/spinlock_types_rt.h>
+# include <linux/rwlock_types_rt.h>
 #endif
 
-#define __RAW_SPIN_LOCK_INITIALIZER(lockname)	\
-	{					\
-	.raw_lock = __ARCH_SPIN_LOCK_UNLOCKED,	\
-	SPIN_DEBUG_INIT(lockname)		\
-	SPIN_DEP_MAP_INIT(lockname) }
-
-#define __RAW_SPIN_LOCK_UNLOCKED(lockname)	\
-	(raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
-
-#define DEFINE_RAW_SPINLOCK(x)	raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
-
-typedef struct spinlock {
-	union {
-		struct raw_spinlock rlock;
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
-		struct {
-			u8 __padding[LOCK_PADSIZE];
-			struct lockdep_map dep_map;
-		};
-#endif
-	};
-} spinlock_t;
-
-#define __SPIN_LOCK_INITIALIZER(lockname) \
-	{ { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
-
-#define __SPIN_LOCK_UNLOCKED(lockname) \
-	(spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
-
-#define DEFINE_SPINLOCK(x)	spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
-
-#include <linux/rwlock_types.h>
-
 #endif /* __LINUX_SPINLOCK_TYPES_H */
Index: linux-4.19.25-rt16/include/linux/spinlock_types_nort.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/spinlock_types_nort.h
@@ -0,0 +1,33 @@
+#ifndef __LINUX_SPINLOCK_TYPES_NORT_H
+#define __LINUX_SPINLOCK_TYPES_NORT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+/*
+ * The non RT version maps spinlocks to raw_spinlocks
+ */
+typedef struct spinlock {
+	union {
+		struct raw_spinlock rlock;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
+		struct {
+			u8 __padding[LOCK_PADSIZE];
+			struct lockdep_map dep_map;
+		};
+#endif
+	};
+} spinlock_t;
+
+#define __SPIN_LOCK_INITIALIZER(lockname) \
+	{ { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
+
+#define __SPIN_LOCK_UNLOCKED(lockname) \
+	(spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_SPINLOCK(x)	spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
+
+#endif
Index: linux-4.19.25-rt16/include/linux/spinlock_types_raw.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/spinlock_types_raw.h
@@ -0,0 +1,55 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
+#define __LINUX_SPINLOCK_TYPES_RAW_H
+
+#include <linux/types.h>
+
+#if defined(CONFIG_SMP)
+# include <asm/spinlock_types.h>
+#else
+# include <linux/spinlock_types_up.h>
+#endif
+
+#include <linux/lockdep.h>
+
+typedef struct raw_spinlock {
+	arch_spinlock_t raw_lock;
+#ifdef CONFIG_DEBUG_SPINLOCK
+	unsigned int magic, owner_cpu;
+	void *owner;
+#endif
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map dep_map;
+#endif
+} raw_spinlock_t;
+
+#define SPINLOCK_MAGIC		0xdead4ead
+
+#define SPINLOCK_OWNER_INIT	((void *)-1L)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define SPIN_DEP_MAP_INIT(lockname)	.dep_map = { .name = #lockname }
+#else
+# define SPIN_DEP_MAP_INIT(lockname)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define SPIN_DEBUG_INIT(lockname)		\
+	.magic = SPINLOCK_MAGIC,		\
+	.owner_cpu = -1,			\
+	.owner = SPINLOCK_OWNER_INIT,
+#else
+# define SPIN_DEBUG_INIT(lockname)
+#endif
+
+#define __RAW_SPIN_LOCK_INITIALIZER(lockname)	\
+	{					\
+	.raw_lock = __ARCH_SPIN_LOCK_UNLOCKED,	\
+	SPIN_DEBUG_INIT(lockname)		\
+	SPIN_DEP_MAP_INIT(lockname) }
+
+#define __RAW_SPIN_LOCK_UNLOCKED(lockname)	\
+	(raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_RAW_SPINLOCK(x)	raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
+
+#endif
Index: linux-4.19.25-rt16/include/linux/spinlock_types_rt.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/spinlock_types_rt.h
@@ -0,0 +1,48 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RT_H
+#define __LINUX_SPINLOCK_TYPES_RT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+#include <linux/cache.h>
+
+/*
+ * PREEMPT_RT: spinlocks - an RT mutex plus lock-break field:
+ */
+typedef struct spinlock {
+	struct rt_mutex		lock;
+	unsigned int		break_lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+} spinlock_t;
+
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+# define __RT_SPIN_INITIALIZER(name) \
+	{ \
+	.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
+	.save_state = 1, \
+	.file = __FILE__, \
+	.line = __LINE__ , \
+	}
+#else
+# define __RT_SPIN_INITIALIZER(name) \
+	{								\
+	.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock),		\
+	.save_state = 1, \
+	}
+#endif
+
+/*
+.wait_list = PLIST_HEAD_INIT_RAW((name).lock.wait_list, (name).lock.wait_lock)
+*/
+
+#define __SPIN_LOCK_UNLOCKED(name)			\
+	{ .lock = __RT_SPIN_INITIALIZER(name.lock),		\
+	  SPIN_DEP_MAP_INIT(name) }
+
+#define DEFINE_SPINLOCK(name) \
+	spinlock_t name = __SPIN_LOCK_UNLOCKED(name)
+
+#endif
Index: linux-4.19.25-rt16/include/linux/spinlock_types_up.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/spinlock_types_up.h
+++ linux-4.19.25-rt16/include/linux/spinlock_types_up.h
@@ -1,10 +1,6 @@
 #ifndef __LINUX_SPINLOCK_TYPES_UP_H
 #define __LINUX_SPINLOCK_TYPES_UP_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
-# error "please don't include this file directly"
-#endif
-
 /*
  * include/linux/spinlock_types_up.h - spinlock type definitions for UP
  *
Index: linux-4.19.25-rt16/include/linux/suspend.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/suspend.h
+++ linux-4.19.25-rt16/include/linux/suspend.h
@@ -196,6 +196,12 @@ struct platform_s2idle_ops {
 	void (*end)(void);
 };
 
+#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION)
+extern bool pm_in_action;
+#else
+# define pm_in_action false
+#endif
+
 #ifdef CONFIG_SUSPEND
 extern suspend_state_t mem_sleep_current;
 extern suspend_state_t mem_sleep_default;
Index: linux-4.19.25-rt16/include/linux/swait.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/swait.h
+++ linux-4.19.25-rt16/include/linux/swait.h
@@ -160,7 +160,9 @@ static inline bool swq_has_sleeper(struc
 extern void swake_up_one(struct swait_queue_head *q);
 extern void swake_up_all(struct swait_queue_head *q);
 extern void swake_up_locked(struct swait_queue_head *q);
+extern void swake_up_all_locked(struct swait_queue_head *q);
 
+extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
 extern void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state);
 extern long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state);
 
Index: linux-4.19.25-rt16/include/linux/swap.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/swap.h
+++ linux-4.19.25-rt16/include/linux/swap.h
@@ -12,6 +12,7 @@
 #include <linux/fs.h>
 #include <linux/atomic.h>
 #include <linux/page-flags.h>
+#include <linux/locallock.h>
 #include <asm/page.h>
 
 struct notifier_block;
@@ -331,6 +332,7 @@ extern unsigned long nr_free_pagecache_p
 
 
 /* linux/mm/swap.c */
+DECLARE_LOCAL_IRQ_LOCK(swapvec_lock);
 extern void lru_cache_add(struct page *);
 extern void lru_cache_add_anon(struct page *page);
 extern void lru_cache_add_file(struct page *page);
Index: linux-4.19.25-rt16/include/linux/swork.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/linux/swork.h
@@ -0,0 +1,24 @@
+#ifndef _LINUX_SWORK_H
+#define _LINUX_SWORK_H
+
+#include <linux/list.h>
+
+struct swork_event {
+	struct list_head item;
+	unsigned long flags;
+	void (*func)(struct swork_event *);
+};
+
+static inline void INIT_SWORK(struct swork_event *event,
+			      void (*func)(struct swork_event *))
+{
+	event->flags = 0;
+	event->func = func;
+}
+
+bool swork_queue(struct swork_event *sev);
+
+int swork_get(void);
+void swork_put(void);
+
+#endif /* _LINUX_SWORK_H */
Index: linux-4.19.25-rt16/include/linux/thread_info.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/thread_info.h
+++ linux-4.19.25-rt16/include/linux/thread_info.h
@@ -97,7 +97,17 @@ static inline int test_ti_thread_flag(st
 #define test_thread_flag(flag) \
 	test_ti_thread_flag(current_thread_info(), flag)
 
-#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+#ifdef CONFIG_PREEMPT_LAZY
+#define tif_need_resched()	(test_thread_flag(TIF_NEED_RESCHED) || \
+				 test_thread_flag(TIF_NEED_RESCHED_LAZY))
+#define tif_need_resched_now()	(test_thread_flag(TIF_NEED_RESCHED))
+#define tif_need_resched_lazy()	test_thread_flag(TIF_NEED_RESCHED_LAZY))
+
+#else
+#define tif_need_resched()	test_thread_flag(TIF_NEED_RESCHED)
+#define tif_need_resched_now()	test_thread_flag(TIF_NEED_RESCHED)
+#define tif_need_resched_lazy()	0
+#endif
 
 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
 static inline int arch_within_stack_frames(const void * const stack,
Index: linux-4.19.25-rt16/include/linux/timer.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/timer.h
+++ linux-4.19.25-rt16/include/linux/timer.h
@@ -172,7 +172,7 @@ extern void add_timer(struct timer_list
 
 extern int try_to_del_timer_sync(struct timer_list *timer);
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
   extern int del_timer_sync(struct timer_list *timer);
 #else
 # define del_timer_sync(t)		del_timer(t)
Index: linux-4.19.25-rt16/include/linux/trace_events.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/trace_events.h
+++ linux-4.19.25-rt16/include/linux/trace_events.h
@@ -62,6 +62,9 @@ struct trace_entry {
 	unsigned char		flags;
 	unsigned char		preempt_count;
 	int			pid;
+	unsigned short		migrate_disable;
+	unsigned short		padding;
+	unsigned char		preempt_lazy_count;
 };
 
 #define TRACE_EVENT_TYPE_MAX						\
Index: linux-4.19.25-rt16/include/linux/uaccess.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/uaccess.h
+++ linux-4.19.25-rt16/include/linux/uaccess.h
@@ -185,6 +185,7 @@ static __always_inline void pagefault_di
  */
 static inline void pagefault_disable(void)
 {
+	migrate_disable();
 	pagefault_disabled_inc();
 	/*
 	 * make sure to have issued the store before a pagefault
@@ -201,6 +202,7 @@ static inline void pagefault_enable(void
 	 */
 	barrier();
 	pagefault_disabled_dec();
+	migrate_enable();
 }
 
 /*
Index: linux-4.19.25-rt16/include/linux/vmstat.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/vmstat.h
+++ linux-4.19.25-rt16/include/linux/vmstat.h
@@ -54,7 +54,9 @@ DECLARE_PER_CPU(struct vm_event_state, v
  */
 static inline void __count_vm_event(enum vm_event_item item)
 {
+	preempt_disable_rt();
 	raw_cpu_inc(vm_event_states.event[item]);
+	preempt_enable_rt();
 }
 
 static inline void count_vm_event(enum vm_event_item item)
@@ -64,7 +66,9 @@ static inline void count_vm_event(enum v
 
 static inline void __count_vm_events(enum vm_event_item item, long delta)
 {
+	preempt_disable_rt();
 	raw_cpu_add(vm_event_states.event[item], delta);
+	preempt_enable_rt();
 }
 
 static inline void count_vm_events(enum vm_event_item item, long delta)
Index: linux-4.19.25-rt16/include/linux/wait.h
===================================================================
--- linux-4.19.25-rt16.orig/include/linux/wait.h
+++ linux-4.19.25-rt16/include/linux/wait.h
@@ -10,6 +10,7 @@
 
 #include <asm/current.h>
 #include <uapi/linux/wait.h>
+#include <linux/atomic.h>
 
 typedef struct wait_queue_entry wait_queue_entry_t;
 
@@ -488,8 +489,8 @@ do {										\
 	int __ret = 0;								\
 	struct hrtimer_sleeper __t;						\
 										\
-	hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);	\
-	hrtimer_init_sleeper(&__t, current);					\
+	hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC, HRTIMER_MODE_REL,	\
+				      current);					\
 	if ((timeout) != KTIME_MAX)						\
 		hrtimer_start_range_ns(&__t.timer, timeout,			\
 				       current->timer_slack_ns,			\
Index: linux-4.19.25-rt16/include/net/gen_stats.h
===================================================================
--- linux-4.19.25-rt16.orig/include/net/gen_stats.h
+++ linux-4.19.25-rt16/include/net/gen_stats.h
@@ -6,6 +6,7 @@
 #include <linux/socket.h>
 #include <linux/rtnetlink.h>
 #include <linux/pkt_sched.h>
+#include <net/net_seq_lock.h>
 
 struct gnet_stats_basic_cpu {
 	struct gnet_stats_basic_packed bstats;
@@ -36,11 +37,11 @@ int gnet_stats_start_copy_compat(struct
 				 spinlock_t *lock, struct gnet_dump *d,
 				 int padattr);
 
-int gnet_stats_copy_basic(const seqcount_t *running,
+int gnet_stats_copy_basic(net_seqlock_t *running,
 			  struct gnet_dump *d,
 			  struct gnet_stats_basic_cpu __percpu *cpu,
 			  struct gnet_stats_basic_packed *b);
-void __gnet_stats_copy_basic(const seqcount_t *running,
+void __gnet_stats_copy_basic(net_seqlock_t *running,
 			     struct gnet_stats_basic_packed *bstats,
 			     struct gnet_stats_basic_cpu __percpu *cpu,
 			     struct gnet_stats_basic_packed *b);
@@ -60,13 +61,13 @@ int gen_new_estimator(struct gnet_stats_
 		      struct gnet_stats_basic_cpu __percpu *cpu_bstats,
 		      struct net_rate_estimator __rcu **rate_est,
 		      spinlock_t *lock,
-		      seqcount_t *running, struct nlattr *opt);
+		      net_seqlock_t *running, struct nlattr *opt);
 void gen_kill_estimator(struct net_rate_estimator __rcu **ptr);
 int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
 			  struct gnet_stats_basic_cpu __percpu *cpu_bstats,
 			  struct net_rate_estimator __rcu **ptr,
 			  spinlock_t *lock,
-			  seqcount_t *running, struct nlattr *opt);
+			  net_seqlock_t *running, struct nlattr *opt);
 bool gen_estimator_active(struct net_rate_estimator __rcu **ptr);
 bool gen_estimator_read(struct net_rate_estimator __rcu **ptr,
 			struct gnet_stats_rate_est64 *sample);
Index: linux-4.19.25-rt16/include/net/neighbour.h
===================================================================
--- linux-4.19.25-rt16.orig/include/net/neighbour.h
+++ linux-4.19.25-rt16/include/net/neighbour.h
@@ -451,7 +451,7 @@ static inline int neigh_hh_bridge(struct
 }
 #endif
 
-static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
+static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
 {
 	unsigned int hh_alen = 0;
 	unsigned int seq;
@@ -493,7 +493,7 @@ static inline int neigh_hh_output(const
 
 static inline int neigh_output(struct neighbour *n, struct sk_buff *skb)
 {
-	const struct hh_cache *hh = &n->hh;
+	struct hh_cache *hh = &n->hh;
 
 	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
 		return neigh_hh_output(hh, skb);
@@ -534,7 +534,7 @@ struct neighbour_cb {
 
 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
 
-static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
+static inline void neigh_ha_snapshot(char *dst, struct neighbour *n,
 				     const struct net_device *dev)
 {
 	unsigned int seq;
Index: linux-4.19.25-rt16/include/net/net_seq_lock.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/net/net_seq_lock.h
@@ -0,0 +1,15 @@
+#ifndef __NET_NET_SEQ_LOCK_H__
+#define __NET_NET_SEQ_LOCK_H__
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define net_seqlock_t			seqlock_t
+# define net_seq_begin(__r)		read_seqbegin(__r)
+# define net_seq_retry(__r, __s)	read_seqretry(__r, __s)
+
+#else
+# define net_seqlock_t			seqcount_t
+# define net_seq_begin(__r)		read_seqcount_begin(__r)
+# define net_seq_retry(__r, __s)	read_seqcount_retry(__r, __s)
+#endif
+
+#endif
Index: linux-4.19.25-rt16/include/net/sch_generic.h
===================================================================
--- linux-4.19.25-rt16.orig/include/net/sch_generic.h
+++ linux-4.19.25-rt16/include/net/sch_generic.h
@@ -10,6 +10,7 @@
 #include <linux/percpu.h>
 #include <linux/dynamic_queue_limits.h>
 #include <linux/list.h>
+#include <net/net_seq_lock.h>
 #include <linux/refcount.h>
 #include <linux/workqueue.h>
 #include <net/gen_stats.h>
@@ -100,7 +101,7 @@ struct Qdisc {
 	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
 	struct qdisc_skb_head	q;
 	struct gnet_stats_basic_packed bstats;
-	seqcount_t		running;
+	net_seqlock_t		running;
 	struct gnet_stats_queue	qstats;
 	unsigned long		state;
 	struct Qdisc            *next_sched;
@@ -121,7 +122,11 @@ static inline bool qdisc_is_running(stru
 {
 	if (qdisc->flags & TCQ_F_NOLOCK)
 		return spin_is_locked(&qdisc->seqlock);
+#ifdef CONFIG_PREEMPT_RT_BASE
+	return spin_is_locked(&qdisc->running.lock) ? true : false;
+#else
 	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
+#endif
 }
 
 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
@@ -132,17 +137,27 @@ static inline bool qdisc_run_begin(struc
 	} else if (qdisc_is_running(qdisc)) {
 		return false;
 	}
+#ifdef CONFIG_PREEMPT_RT_BASE
+	if (try_write_seqlock(&qdisc->running))
+		return true;
+	return false;
+#else
 	/* Variant of write_seqcount_begin() telling lockdep a trylock
 	 * was attempted.
 	 */
 	raw_write_seqcount_begin(&qdisc->running);
 	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
 	return true;
+#endif
 }
 
 static inline void qdisc_run_end(struct Qdisc *qdisc)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	write_sequnlock(&qdisc->running);
+#else
 	write_seqcount_end(&qdisc->running);
+#endif
 	if (qdisc->flags & TCQ_F_NOLOCK)
 		spin_unlock(&qdisc->seqlock);
 }
@@ -453,7 +468,7 @@ static inline spinlock_t *qdisc_root_sle
 	return qdisc_lock(root);
 }
 
-static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
+static inline net_seqlock_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
 {
 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
 
Index: linux-4.19.25-rt16/include/soc/at91/atmel_tcb.h
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/include/soc/at91/atmel_tcb.h
@@ -0,0 +1,183 @@
+//SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2018 Microchip */
+
+#ifndef __SOC_ATMEL_TCB_H
+#define __SOC_ATMEL_TCB_H
+
+/* Channel registers */
+#define ATMEL_TC_COFFS(c)		((c) * 0x40)
+#define ATMEL_TC_CCR(c)			ATMEL_TC_COFFS(c)
+#define ATMEL_TC_CMR(c)			(ATMEL_TC_COFFS(c) + 0x4)
+#define ATMEL_TC_SMMR(c)		(ATMEL_TC_COFFS(c) + 0x8)
+#define ATMEL_TC_RAB(c)			(ATMEL_TC_COFFS(c) + 0xc)
+#define ATMEL_TC_CV(c)			(ATMEL_TC_COFFS(c) + 0x10)
+#define ATMEL_TC_RA(c)			(ATMEL_TC_COFFS(c) + 0x14)
+#define ATMEL_TC_RB(c)			(ATMEL_TC_COFFS(c) + 0x18)
+#define ATMEL_TC_RC(c)			(ATMEL_TC_COFFS(c) + 0x1c)
+#define ATMEL_TC_SR(c)			(ATMEL_TC_COFFS(c) + 0x20)
+#define ATMEL_TC_IER(c)			(ATMEL_TC_COFFS(c) + 0x24)
+#define ATMEL_TC_IDR(c)			(ATMEL_TC_COFFS(c) + 0x28)
+#define ATMEL_TC_IMR(c)			(ATMEL_TC_COFFS(c) + 0x2c)
+#define ATMEL_TC_EMR(c)			(ATMEL_TC_COFFS(c) + 0x30)
+
+/* Block registers */
+#define ATMEL_TC_BCR			0xc0
+#define ATMEL_TC_BMR			0xc4
+#define ATMEL_TC_QIER			0xc8
+#define ATMEL_TC_QIDR			0xcc
+#define ATMEL_TC_QIMR			0xd0
+#define ATMEL_TC_QISR			0xd4
+#define ATMEL_TC_FMR			0xd8
+#define ATMEL_TC_WPMR			0xe4
+
+/* CCR fields */
+#define ATMEL_TC_CCR_CLKEN		BIT(0)
+#define ATMEL_TC_CCR_CLKDIS		BIT(1)
+#define ATMEL_TC_CCR_SWTRG		BIT(2)
+
+/* Common CMR fields */
+#define ATMEL_TC_CMR_TCLKS_MSK		GENMASK(2, 0)
+#define ATMEL_TC_CMR_TCLK(x)		(x)
+#define ATMEL_TC_CMR_XC(x)		((x) + 5)
+#define ATMEL_TC_CMR_CLKI		BIT(3)
+#define ATMEL_TC_CMR_BURST_MSK		GENMASK(5, 4)
+#define ATMEL_TC_CMR_BURST_XC(x)	(((x) + 1) << 4)
+#define ATMEL_TC_CMR_WAVE		BIT(15)
+
+/* Capture mode CMR fields */
+#define ATMEL_TC_CMR_LDBSTOP		BIT(6)
+#define ATMEL_TC_CMR_LDBDIS		BIT(7)
+#define ATMEL_TC_CMR_ETRGEDG_MSK	GENMASK(9, 8)
+#define ATMEL_TC_CMR_ETRGEDG_NONE	(0 << 8)
+#define ATMEL_TC_CMR_ETRGEDG_RISING	(1 << 8)
+#define ATMEL_TC_CMR_ETRGEDG_FALLING	(2 << 8)
+#define ATMEL_TC_CMR_ETRGEDG_BOTH	(3 << 8)
+#define ATMEL_TC_CMR_ABETRG		BIT(10)
+#define ATMEL_TC_CMR_CPCTRG		BIT(14)
+#define ATMEL_TC_CMR_LDRA_MSK		GENMASK(17, 16)
+#define ATMEL_TC_CMR_LDRA_NONE		(0 << 16)
+#define ATMEL_TC_CMR_LDRA_RISING	(1 << 16)
+#define ATMEL_TC_CMR_LDRA_FALLING	(2 << 16)
+#define ATMEL_TC_CMR_LDRA_BOTH		(3 << 16)
+#define ATMEL_TC_CMR_LDRB_MSK		GENMASK(19, 18)
+#define ATMEL_TC_CMR_LDRB_NONE		(0 << 18)
+#define ATMEL_TC_CMR_LDRB_RISING	(1 << 18)
+#define ATMEL_TC_CMR_LDRB_FALLING	(2 << 18)
+#define ATMEL_TC_CMR_LDRB_BOTH		(3 << 18)
+#define ATMEL_TC_CMR_SBSMPLR_MSK	GENMASK(22, 20)
+#define ATMEL_TC_CMR_SBSMPLR(x)		((x) << 20)
+
+/* Waveform mode CMR fields */
+#define ATMEL_TC_CMR_CPCSTOP		BIT(6)
+#define ATMEL_TC_CMR_CPCDIS		BIT(7)
+#define ATMEL_TC_CMR_EEVTEDG_MSK	GENMASK(9, 8)
+#define ATMEL_TC_CMR_EEVTEDG_NONE	(0 << 8)
+#define ATMEL_TC_CMR_EEVTEDG_RISING	(1 << 8)
+#define ATMEL_TC_CMR_EEVTEDG_FALLING	(2 << 8)
+#define ATMEL_TC_CMR_EEVTEDG_BOTH	(3 << 8)
+#define ATMEL_TC_CMR_EEVT_MSK		GENMASK(11, 10)
+#define ATMEL_TC_CMR_EEVT_XC(x)		(((x) + 1) << 10)
+#define ATMEL_TC_CMR_ENETRG		BIT(12)
+#define ATMEL_TC_CMR_WAVESEL_MSK	GENMASK(14, 13)
+#define ATMEL_TC_CMR_WAVESEL_UP		(0 << 13)
+#define ATMEL_TC_CMR_WAVESEL_UPDOWN	(1 << 13)
+#define ATMEL_TC_CMR_WAVESEL_UPRC	(2 << 13)
+#define ATMEL_TC_CMR_WAVESEL_UPDOWNRC	(3 << 13)
+#define ATMEL_TC_CMR_ACPA_MSK		GENMASK(17, 16)
+#define ATMEL_TC_CMR_ACPA(a)		(ATMEL_TC_CMR_ACTION_##a << 16)
+#define ATMEL_TC_CMR_ACPC_MSK		GENMASK(19, 18)
+#define ATMEL_TC_CMR_ACPC(a)		(ATMEL_TC_CMR_ACTION_##a << 18)
+#define ATMEL_TC_CMR_AEEVT_MSK		GENMASK(21, 20)
+#define ATMEL_TC_CMR_AEEVT(a)		(ATMEL_TC_CMR_ACTION_##a << 20)
+#define ATMEL_TC_CMR_ASWTRG_MSK		GENMASK(23, 22)
+#define ATMEL_TC_CMR_ASWTRG(a)		(ATMEL_TC_CMR_ACTION_##a << 22)
+#define ATMEL_TC_CMR_BCPB_MSK		GENMASK(25, 24)
+#define ATMEL_TC_CMR_BCPB(a)		(ATMEL_TC_CMR_ACTION_##a << 24)
+#define ATMEL_TC_CMR_BCPC_MSK		GENMASK(27, 26)
+#define ATMEL_TC_CMR_BCPC(a)		(ATMEL_TC_CMR_ACTION_##a << 26)
+#define ATMEL_TC_CMR_BEEVT_MSK		GENMASK(29, 28)
+#define ATMEL_TC_CMR_BEEVT(a)		(ATMEL_TC_CMR_ACTION_##a << 28)
+#define ATMEL_TC_CMR_BSWTRG_MSK		GENMASK(31, 30)
+#define ATMEL_TC_CMR_BSWTRG(a)		(ATMEL_TC_CMR_ACTION_##a << 30)
+#define ATMEL_TC_CMR_ACTION_NONE	0
+#define ATMEL_TC_CMR_ACTION_SET		1
+#define ATMEL_TC_CMR_ACTION_CLEAR	2
+#define ATMEL_TC_CMR_ACTION_TOGGLE	3
+
+/* SMMR fields */
+#define ATMEL_TC_SMMR_GCEN		BIT(0)
+#define ATMEL_TC_SMMR_DOWN		BIT(1)
+
+/* SR/IER/IDR/IMR fields */
+#define ATMEL_TC_COVFS			BIT(0)
+#define ATMEL_TC_LOVRS			BIT(1)
+#define ATMEL_TC_CPAS			BIT(2)
+#define ATMEL_TC_CPBS			BIT(3)
+#define ATMEL_TC_CPCS			BIT(4)
+#define ATMEL_TC_LDRAS			BIT(5)
+#define ATMEL_TC_LDRBS			BIT(6)
+#define ATMEL_TC_ETRGS			BIT(7)
+#define ATMEL_TC_CLKSTA			BIT(16)
+#define ATMEL_TC_MTIOA			BIT(17)
+#define ATMEL_TC_MTIOB			BIT(18)
+
+/* EMR fields */
+#define ATMEL_TC_EMR_TRIGSRCA_MSK	GENMASK(1, 0)
+#define ATMEL_TC_EMR_TRIGSRCA_TIOA	0
+#define ATMEL_TC_EMR_TRIGSRCA_PWMX	1
+#define ATMEL_TC_EMR_TRIGSRCB_MSK	GENMASK(5, 4)
+#define ATMEL_TC_EMR_TRIGSRCB_TIOB	(0 << 4)
+#define ATMEL_TC_EMR_TRIGSRCB_PWM	(1 << 4)
+#define ATMEL_TC_EMR_NOCLKDIV		BIT(8)
+
+/* BCR fields */
+#define ATMEL_TC_BCR_SYNC		BIT(0)
+
+/* BMR fields */
+#define ATMEL_TC_BMR_TCXC_MSK(c)	GENMASK(((c) * 2) + 1, (c) * 2)
+#define ATMEL_TC_BMR_TCXC(x, c)		((x) << (2 * (c)))
+#define ATMEL_TC_BMR_QDEN		BIT(8)
+#define ATMEL_TC_BMR_POSEN		BIT(9)
+#define ATMEL_TC_BMR_SPEEDEN		BIT(10)
+#define ATMEL_TC_BMR_QDTRANS		BIT(11)
+#define ATMEL_TC_BMR_EDGPHA		BIT(12)
+#define ATMEL_TC_BMR_INVA		BIT(13)
+#define ATMEL_TC_BMR_INVB		BIT(14)
+#define ATMEL_TC_BMR_INVIDX		BIT(15)
+#define ATMEL_TC_BMR_SWAP		BIT(16)
+#define ATMEL_TC_BMR_IDXPHB		BIT(17)
+#define ATMEL_TC_BMR_AUTOC		BIT(18)
+#define ATMEL_TC_MAXFILT_MSK		GENMASK(25, 20)
+#define ATMEL_TC_MAXFILT(x)		(((x) - 1) << 20)
+#define ATMEL_TC_MAXCMP_MSK		GENMASK(29, 26)
+#define ATMEL_TC_MAXCMP(x)		((x) << 26)
+
+/* QEDC fields */
+#define ATMEL_TC_QEDC_IDX		BIT(0)
+#define ATMEL_TC_QEDC_DIRCHG		BIT(1)
+#define ATMEL_TC_QEDC_QERR		BIT(2)
+#define ATMEL_TC_QEDC_MPE		BIT(3)
+#define ATMEL_TC_QEDC_DIR		BIT(8)
+
+/* FMR fields */
+#define ATMEL_TC_FMR_ENCF(x)		BIT(x)
+
+/* WPMR fields */
+#define ATMEL_TC_WPMR_WPKEY		(0x54494d << 8)
+#define ATMEL_TC_WPMR_WPEN		BIT(0)
+
+static const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
+
+static const struct of_device_id atmel_tcb_dt_ids[] = {
+	{
+		.compatible = "atmel,at91rm9200-tcb",
+		.data = (void *)16,
+	}, {
+		.compatible = "atmel,at91sam9x5-tcb",
+		.data = (void *)32,
+	}, {
+		/* sentinel */
+	}
+};
+
+#endif /* __SOC_ATMEL_TCB_H */
Index: linux-4.19.25-rt16/init/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/init/Kconfig
+++ linux-4.19.25-rt16/init/Kconfig
@@ -781,6 +781,7 @@ config CFS_BANDWIDTH
 config RT_GROUP_SCHED
 	bool "Group scheduling for SCHED_RR/FIFO"
 	depends on CGROUP_SCHED
+	depends on !PREEMPT_RT_FULL
 	default n
 	help
 	  This feature lets you explicitly allocate real CPU bandwidth
@@ -1634,6 +1635,7 @@ choice
 
 config SLAB
 	bool "SLAB"
+	depends on !PREEMPT_RT_FULL
 	select HAVE_HARDENED_USERCOPY_ALLOCATOR
 	help
 	  The regular slab allocator that is established and known to work
@@ -1654,6 +1656,7 @@ config SLUB
 config SLOB
 	depends on EXPERT
 	bool "SLOB (Simple Allocator)"
+	depends on !PREEMPT_RT_FULL
 	help
 	   SLOB replaces the stock allocator with a drastically simpler
 	   allocator. SLOB is generally more space efficient but
@@ -1695,7 +1698,7 @@ config SLAB_FREELIST_HARDENED
 
 config SLUB_CPU_PARTIAL
 	default y
-	depends on SLUB && SMP
+	depends on SLUB && SMP && !PREEMPT_RT_FULL
 	bool "SLUB per cpu partial cache"
 	help
 	  Per cpu partial caches accellerate objects allocation and freeing
Index: linux-4.19.25-rt16/init/Makefile
===================================================================
--- linux-4.19.25-rt16.orig/init/Makefile
+++ linux-4.19.25-rt16/init/Makefile
@@ -34,4 +34,4 @@ silent_chk_compile.h = :
 include/generated/compile.h: FORCE
 	@$($(quiet)chk_compile.h)
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@ \
-	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(KBUILD_CFLAGS)"
+	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CONFIG_PREEMPT_RT_FULL)" "$(CC) $(KBUILD_CFLAGS)"
Index: linux-4.19.25-rt16/init/init_task.c
===================================================================
--- linux-4.19.25-rt16.orig/init/init_task.c
+++ linux-4.19.25-rt16/init/init_task.c
@@ -50,6 +50,12 @@ static struct sighand_struct init_sighan
 	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
 };
 
+#if defined(CONFIG_POSIX_TIMERS) && defined(CONFIG_PREEMPT_RT_BASE)
+# define INIT_TIMER_LIST		.posix_timer_list = NULL,
+#else
+# define INIT_TIMER_LIST
+#endif
+
 /*
  * Set up the first task table, touch at your own risk!. Base=0,
  * limit=0x1fffff (=2MB)
@@ -71,7 +77,8 @@ struct task_struct init_task
 	.static_prio	= MAX_PRIO - 20,
 	.normal_prio	= MAX_PRIO - 20,
 	.policy		= SCHED_NORMAL,
-	.cpus_allowed	= CPU_MASK_ALL,
+	.cpus_ptr	= &init_task.cpus_mask,
+	.cpus_mask	= CPU_MASK_ALL,
 	.nr_cpus_allowed= NR_CPUS,
 	.mm		= NULL,
 	.active_mm	= &init_mm,
@@ -118,6 +125,7 @@ struct task_struct init_task
 	INIT_CPU_TIMERS(init_task)
 	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
 	.timer_slack_ns = 50000, /* 50 usec default slack */
+	INIT_TIMER_LIST
 	.thread_pid	= &init_struct_pid,
 	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
 	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
Index: linux-4.19.25-rt16/init/main.c
===================================================================
--- linux-4.19.25-rt16.orig/init/main.c
+++ linux-4.19.25-rt16/init/main.c
@@ -561,6 +561,7 @@ asmlinkage __visible void __init start_k
 	setup_command_line(command_line);
 	setup_nr_cpu_ids();
 	setup_per_cpu_areas();
+	softirq_early_init();
 	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
 	boot_cpu_hotplug_init();
 
Index: linux-4.19.25-rt16/kernel/Kconfig.locks
===================================================================
--- linux-4.19.25-rt16.orig/kernel/Kconfig.locks
+++ linux-4.19.25-rt16/kernel/Kconfig.locks
@@ -225,11 +225,11 @@ config ARCH_SUPPORTS_ATOMIC_RMW
 
 config MUTEX_SPIN_ON_OWNER
 	def_bool y
-	depends on SMP && ARCH_SUPPORTS_ATOMIC_RMW
+	depends on SMP && ARCH_SUPPORTS_ATOMIC_RMW && !PREEMPT_RT_FULL
 
 config RWSEM_SPIN_ON_OWNER
        def_bool y
-       depends on SMP && RWSEM_XCHGADD_ALGORITHM && ARCH_SUPPORTS_ATOMIC_RMW
+       depends on SMP && RWSEM_XCHGADD_ALGORITHM && ARCH_SUPPORTS_ATOMIC_RMW && !PREEMPT_RT_FULL
 
 config LOCK_SPIN_ON_OWNER
        def_bool y
Index: linux-4.19.25-rt16/kernel/Kconfig.preempt
===================================================================
--- linux-4.19.25-rt16.orig/kernel/Kconfig.preempt
+++ linux-4.19.25-rt16/kernel/Kconfig.preempt
@@ -1,3 +1,16 @@
+config PREEMPT
+	bool
+	select PREEMPT_COUNT
+
+config PREEMPT_RT_BASE
+	bool
+	select PREEMPT
+
+config HAVE_PREEMPT_LAZY
+	bool
+
+config PREEMPT_LAZY
+	def_bool y if HAVE_PREEMPT_LAZY && PREEMPT_RT_FULL
 
 choice
 	prompt "Preemption Model"
@@ -34,10 +47,10 @@ config PREEMPT_VOLUNTARY
 
 	  Select this if you are building a kernel for a desktop system.
 
-config PREEMPT
+config PREEMPT__LL
 	bool "Preemptible Kernel (Low-Latency Desktop)"
 	depends on !ARCH_NO_PREEMPT
-	select PREEMPT_COUNT
+	select PREEMPT
 	select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
 	help
 	  This option reduces the latency of the kernel by making
@@ -54,7 +67,23 @@ config PREEMPT
 	  embedded system with latency requirements in the milliseconds
 	  range.
 
+config PREEMPT_RTB
+	bool "Preemptible Kernel (Basic RT)"
+	select PREEMPT_RT_BASE
+	help
+	  This option is basically the same as (Low-Latency Desktop) but
+	  enables changes which are preliminary for the full preemptible
+	  RT kernel.
+
+config PREEMPT_RT_FULL
+	bool "Fully Preemptible Kernel (RT)"
+	depends on IRQ_FORCED_THREADING
+	select PREEMPT_RT_BASE
+	select PREEMPT_RCU
+	help
+	  All and everything
+
 endchoice
 
 config PREEMPT_COUNT
-       bool
\ No newline at end of file
+       bool
Index: linux-4.19.25-rt16/kernel/cgroup/cgroup.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/cgroup/cgroup.c
+++ linux-4.19.25-rt16/kernel/cgroup/cgroup.c
@@ -4628,10 +4628,10 @@ static void css_free_rwork_fn(struct wor
 	}
 }
 
-static void css_release_work_fn(struct work_struct *work)
+static void css_release_work_fn(struct swork_event *sev)
 {
 	struct cgroup_subsys_state *css =
-		container_of(work, struct cgroup_subsys_state, destroy_work);
+		container_of(sev, struct cgroup_subsys_state, destroy_swork);
 	struct cgroup_subsys *ss = css->ss;
 	struct cgroup *cgrp = css->cgroup;
 
@@ -4691,8 +4691,8 @@ static void css_release(struct percpu_re
 	struct cgroup_subsys_state *css =
 		container_of(ref, struct cgroup_subsys_state, refcnt);
 
-	INIT_WORK(&css->destroy_work, css_release_work_fn);
-	queue_work(cgroup_destroy_wq, &css->destroy_work);
+	INIT_SWORK(&css->destroy_swork, css_release_work_fn);
+	swork_queue(&css->destroy_swork);
 }
 
 static void init_and_link_css(struct cgroup_subsys_state *css,
@@ -5414,6 +5414,7 @@ static int __init cgroup_wq_init(void)
 	 */
 	cgroup_destroy_wq = alloc_workqueue("cgroup_destroy", 0, 1);
 	BUG_ON(!cgroup_destroy_wq);
+	BUG_ON(swork_get());
 	return 0;
 }
 core_initcall(cgroup_wq_init);
Index: linux-4.19.25-rt16/kernel/cgroup/cpuset.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/cgroup/cpuset.c
+++ linux-4.19.25-rt16/kernel/cgroup/cpuset.c
@@ -288,7 +288,7 @@ static struct cpuset top_cpuset = {
  */
 
 static DEFINE_MUTEX(cpuset_mutex);
-static DEFINE_SPINLOCK(callback_lock);
+static DEFINE_RAW_SPINLOCK(callback_lock);
 
 static struct workqueue_struct *cpuset_migrate_mm_wq;
 
@@ -922,9 +922,9 @@ static void update_cpumasks_hier(struct
 			continue;
 		rcu_read_unlock();
 
-		spin_lock_irq(&callback_lock);
+		raw_spin_lock_irq(&callback_lock);
 		cpumask_copy(cp->effective_cpus, new_cpus);
-		spin_unlock_irq(&callback_lock);
+		raw_spin_unlock_irq(&callback_lock);
 
 		WARN_ON(!is_in_v2_mode() &&
 			!cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
@@ -989,9 +989,9 @@ static int update_cpumask(struct cpuset
 	if (retval < 0)
 		return retval;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	/* use trialcs->cpus_allowed as a temp variable */
 	update_cpumasks_hier(cs, trialcs->cpus_allowed);
@@ -1175,9 +1175,9 @@ static void update_nodemasks_hier(struct
 			continue;
 		rcu_read_unlock();
 
-		spin_lock_irq(&callback_lock);
+		raw_spin_lock_irq(&callback_lock);
 		cp->effective_mems = *new_mems;
-		spin_unlock_irq(&callback_lock);
+		raw_spin_unlock_irq(&callback_lock);
 
 		WARN_ON(!is_in_v2_mode() &&
 			!nodes_equal(cp->mems_allowed, cp->effective_mems));
@@ -1245,9 +1245,9 @@ static int update_nodemask(struct cpuset
 	if (retval < 0)
 		goto done;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cs->mems_allowed = trialcs->mems_allowed;
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	/* use trialcs->mems_allowed as a temp variable */
 	update_nodemasks_hier(cs, &trialcs->mems_allowed);
@@ -1338,9 +1338,9 @@ static int update_flag(cpuset_flagbits_t
 	spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs))
 			|| (is_spread_page(cs) != is_spread_page(trialcs)));
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cs->flags = trialcs->flags;
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
 		rebuild_sched_domains_locked();
@@ -1755,7 +1755,7 @@ static int cpuset_common_seq_show(struct
 	cpuset_filetype_t type = seq_cft(sf)->private;
 	int ret = 0;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 
 	switch (type) {
 	case FILE_CPULIST:
@@ -1774,7 +1774,7 @@ static int cpuset_common_seq_show(struct
 		ret = -EINVAL;
 	}
 
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 	return ret;
 }
 
@@ -1989,12 +1989,12 @@ static int cpuset_css_online(struct cgro
 
 	cpuset_inc();
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	if (is_in_v2_mode()) {
 		cpumask_copy(cs->effective_cpus, parent->effective_cpus);
 		cs->effective_mems = parent->effective_mems;
 	}
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))
 		goto out_unlock;
@@ -2021,12 +2021,12 @@ static int cpuset_css_online(struct cgro
 	}
 	rcu_read_unlock();
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cs->mems_allowed = parent->mems_allowed;
 	cs->effective_mems = parent->mems_allowed;
 	cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
 	cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
 	return 0;
@@ -2065,7 +2065,7 @@ static void cpuset_css_free(struct cgrou
 static void cpuset_bind(struct cgroup_subsys_state *root_css)
 {
 	mutex_lock(&cpuset_mutex);
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 
 	if (is_in_v2_mode()) {
 		cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask);
@@ -2076,7 +2076,7 @@ static void cpuset_bind(struct cgroup_su
 		top_cpuset.mems_allowed = top_cpuset.effective_mems;
 	}
 
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 	mutex_unlock(&cpuset_mutex);
 }
 
@@ -2090,7 +2090,7 @@ static void cpuset_fork(struct task_stru
 	if (task_css_is_root(task, cpuset_cgrp_id))
 		return;
 
-	set_cpus_allowed_ptr(task, &current->cpus_allowed);
+	set_cpus_allowed_ptr(task, current->cpus_ptr);
 	task->mems_allowed = current->mems_allowed;
 }
 
@@ -2174,12 +2174,12 @@ hotplug_update_tasks_legacy(struct cpuse
 {
 	bool is_empty;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cpumask_copy(cs->cpus_allowed, new_cpus);
 	cpumask_copy(cs->effective_cpus, new_cpus);
 	cs->mems_allowed = *new_mems;
 	cs->effective_mems = *new_mems;
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	/*
 	 * Don't call update_tasks_cpumask() if the cpuset becomes empty,
@@ -2216,10 +2216,10 @@ hotplug_update_tasks(struct cpuset *cs,
 	if (nodes_empty(*new_mems))
 		*new_mems = parent_cs(cs)->effective_mems;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cpumask_copy(cs->effective_cpus, new_cpus);
 	cs->effective_mems = *new_mems;
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	if (cpus_updated)
 		update_tasks_cpumask(cs);
@@ -2312,21 +2312,21 @@ static void cpuset_hotplug_workfn(struct
 
 	/* synchronize cpus_allowed to cpu_active_mask */
 	if (cpus_updated) {
-		spin_lock_irq(&callback_lock);
+		raw_spin_lock_irq(&callback_lock);
 		if (!on_dfl)
 			cpumask_copy(top_cpuset.cpus_allowed, &new_cpus);
 		cpumask_copy(top_cpuset.effective_cpus, &new_cpus);
-		spin_unlock_irq(&callback_lock);
+		raw_spin_unlock_irq(&callback_lock);
 		/* we don't mess with cpumasks of tasks in top_cpuset */
 	}
 
 	/* synchronize mems_allowed to N_MEMORY */
 	if (mems_updated) {
-		spin_lock_irq(&callback_lock);
+		raw_spin_lock_irq(&callback_lock);
 		if (!on_dfl)
 			top_cpuset.mems_allowed = new_mems;
 		top_cpuset.effective_mems = new_mems;
-		spin_unlock_irq(&callback_lock);
+		raw_spin_unlock_irq(&callback_lock);
 		update_tasks_nodemask(&top_cpuset);
 	}
 
@@ -2425,11 +2425,11 @@ void cpuset_cpus_allowed(struct task_str
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&callback_lock, flags);
+	raw_spin_lock_irqsave(&callback_lock, flags);
 	rcu_read_lock();
 	guarantee_online_cpus(task_cs(tsk), pmask);
 	rcu_read_unlock();
-	spin_unlock_irqrestore(&callback_lock, flags);
+	raw_spin_unlock_irqrestore(&callback_lock, flags);
 }
 
 void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
@@ -2477,11 +2477,11 @@ nodemask_t cpuset_mems_allowed(struct ta
 	nodemask_t mask;
 	unsigned long flags;
 
-	spin_lock_irqsave(&callback_lock, flags);
+	raw_spin_lock_irqsave(&callback_lock, flags);
 	rcu_read_lock();
 	guarantee_online_mems(task_cs(tsk), &mask);
 	rcu_read_unlock();
-	spin_unlock_irqrestore(&callback_lock, flags);
+	raw_spin_unlock_irqrestore(&callback_lock, flags);
 
 	return mask;
 }
@@ -2573,14 +2573,14 @@ bool __cpuset_node_allowed(int node, gfp
 		return true;
 
 	/* Not hardwall and node outside mems_allowed: scan up cpusets */
-	spin_lock_irqsave(&callback_lock, flags);
+	raw_spin_lock_irqsave(&callback_lock, flags);
 
 	rcu_read_lock();
 	cs = nearest_hardwall_ancestor(task_cs(current));
 	allowed = node_isset(node, cs->mems_allowed);
 	rcu_read_unlock();
 
-	spin_unlock_irqrestore(&callback_lock, flags);
+	raw_spin_unlock_irqrestore(&callback_lock, flags);
 	return allowed;
 }
 
Index: linux-4.19.25-rt16/kernel/cgroup/rstat.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/cgroup/rstat.c
+++ linux-4.19.25-rt16/kernel/cgroup/rstat.c
@@ -159,8 +159,9 @@ static void cgroup_rstat_flush_locked(st
 		raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock,
 						       cpu);
 		struct cgroup *pos = NULL;
+		unsigned long flags;
 
-		raw_spin_lock(cpu_lock);
+		raw_spin_lock_irqsave(cpu_lock, flags);
 		while ((pos = cgroup_rstat_cpu_pop_updated(pos, cgrp, cpu))) {
 			struct cgroup_subsys_state *css;
 
@@ -172,7 +173,7 @@ static void cgroup_rstat_flush_locked(st
 				css->ss->css_rstat_flush(css, cpu);
 			rcu_read_unlock();
 		}
-		raw_spin_unlock(cpu_lock);
+		raw_spin_unlock_irqrestore(cpu_lock, flags);
 
 		/* if @may_sleep, play nice and yield if necessary */
 		if (may_sleep && (need_resched() ||
Index: linux-4.19.25-rt16/kernel/cpu.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/cpu.c
+++ linux-4.19.25-rt16/kernel/cpu.c
@@ -75,6 +75,11 @@ static DEFINE_PER_CPU(struct cpuhp_cpu_s
 	.fail = CPUHP_INVALID,
 };
 
+#if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PREEMPT_RT_FULL)
+static DEFINE_PER_CPU(struct rt_rw_lock, cpuhp_pin_lock) = \
+	__RWLOCK_RT_INITIALIZER(cpuhp_pin_lock);
+#endif
+
 #if defined(CONFIG_LOCKDEP) && defined(CONFIG_SMP)
 static struct lockdep_map cpuhp_state_up_map =
 	STATIC_LOCKDEP_MAP_INIT("cpuhp_state-up", &cpuhp_state_up_map);
@@ -281,6 +286,55 @@ static int cpu_hotplug_disabled;
 
 #ifdef CONFIG_HOTPLUG_CPU
 
+/**
+ * pin_current_cpu - Prevent the current cpu from being unplugged
+ */
+void pin_current_cpu(void)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+	struct rt_rw_lock *cpuhp_pin;
+	unsigned int cpu;
+	int ret;
+
+again:
+	cpuhp_pin = this_cpu_ptr(&cpuhp_pin_lock);
+	ret = __read_rt_trylock(cpuhp_pin);
+	if (ret) {
+		current->pinned_on_cpu = smp_processor_id();
+		return;
+	}
+	cpu = smp_processor_id();
+	preempt_lazy_enable();
+	preempt_enable();
+
+	__read_rt_lock(cpuhp_pin);
+
+	preempt_disable();
+	preempt_lazy_disable();
+	if (cpu != smp_processor_id()) {
+		__read_rt_unlock(cpuhp_pin);
+		goto again;
+	}
+	current->pinned_on_cpu = cpu;
+#endif
+}
+
+/**
+ * unpin_current_cpu - Allow unplug of current cpu
+ */
+void unpin_current_cpu(void)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+	struct rt_rw_lock *cpuhp_pin = this_cpu_ptr(&cpuhp_pin_lock);
+
+	if (WARN_ON(current->pinned_on_cpu != smp_processor_id()))
+		cpuhp_pin = per_cpu_ptr(&cpuhp_pin_lock, current->pinned_on_cpu);
+
+	current->pinned_on_cpu = -1;
+	__read_rt_unlock(cpuhp_pin);
+#endif
+}
+
 DEFINE_STATIC_PERCPU_RWSEM(cpu_hotplug_lock);
 
 void cpus_read_lock(void)
@@ -838,6 +892,9 @@ static int take_cpu_down(void *_param)
 
 static int takedown_cpu(unsigned int cpu)
 {
+#ifdef CONFIG_PREEMPT_RT_FULL
+	struct rt_rw_lock *cpuhp_pin = per_cpu_ptr(&cpuhp_pin_lock, cpu);
+#endif
 	struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
 	int err;
 
@@ -850,11 +907,18 @@ static int takedown_cpu(unsigned int cpu
 	 */
 	irq_lock_sparse();
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	__write_rt_lock(cpuhp_pin);
+#endif
+
 	/*
 	 * So now all preempt/rcu users must observe !cpu_active().
 	 */
 	err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu));
 	if (err) {
+#ifdef CONFIG_PREEMPT_RT_FULL
+		__write_rt_unlock(cpuhp_pin);
+#endif
 		/* CPU refused to die */
 		irq_unlock_sparse();
 		/* Unpark the hotplug thread so we can rollback there */
@@ -873,6 +937,9 @@ static int takedown_cpu(unsigned int cpu
 	wait_for_ap_thread(st, false);
 	BUG_ON(st->state != CPUHP_AP_IDLE_DEAD);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	__write_rt_unlock(cpuhp_pin);
+#endif
 	/* Interrupts are moved away from the dying cpu, reenable alloc/free */
 	irq_unlock_sparse();
 
Index: linux-4.19.25-rt16/kernel/debug/kdb/kdb_io.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/debug/kdb/kdb_io.c
+++ linux-4.19.25-rt16/kernel/debug/kdb/kdb_io.c
@@ -857,9 +857,11 @@ int kdb_printf(const char *fmt, ...)
 	va_list ap;
 	int r;
 
+	kdb_trap_printk++;
 	va_start(ap, fmt);
 	r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
 	va_end(ap);
+	kdb_trap_printk--;
 
 	return r;
 }
Index: linux-4.19.25-rt16/kernel/events/core.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/events/core.c
+++ linux-4.19.25-rt16/kernel/events/core.c
@@ -1102,7 +1102,7 @@ static void __perf_mux_hrtimer_init(stru
 	cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
 
 	raw_spin_lock_init(&cpuctx->hrtimer_lock);
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
+	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
 	timer->function = perf_mux_hrtimer_handler;
 }
 
@@ -9183,7 +9183,7 @@ static void perf_swevent_init_hrtimer(st
 	if (!is_sampling_event(event))
 		return;
 
-	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	hwc->hrtimer.function = perf_swevent_hrtimer;
 
 	/*
Index: linux-4.19.25-rt16/kernel/exit.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/exit.c
+++ linux-4.19.25-rt16/kernel/exit.c
@@ -160,7 +160,7 @@ static void __exit_signal(struct task_st
 	 * Do this under ->siglock, we can race with another thread
 	 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
 	 */
-	flush_sigqueue(&tsk->pending);
+	flush_task_sigqueue(tsk);
 	tsk->sighand = NULL;
 	spin_unlock(&sighand->siglock);
 
Index: linux-4.19.25-rt16/kernel/fork.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/fork.c
+++ linux-4.19.25-rt16/kernel/fork.c
@@ -40,6 +40,7 @@
 #include <linux/hmm.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
+#include <linux/kprobes.h>
 #include <linux/vmacache.h>
 #include <linux/nsproxy.h>
 #include <linux/capability.h>
@@ -637,6 +638,19 @@ void __mmdrop(struct mm_struct *mm)
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+/*
+ * RCU callback for delayed mm drop. Not strictly rcu, but we don't
+ * want another facility to make this work.
+ */
+void __mmdrop_delayed(struct rcu_head *rhp)
+{
+	struct mm_struct *mm = container_of(rhp, struct mm_struct, delayed_drop);
+
+	__mmdrop(mm);
+}
+#endif
+
 static void mmdrop_async_fn(struct work_struct *work)
 {
 	struct mm_struct *mm;
@@ -671,13 +685,24 @@ static inline void put_signal_struct(str
 	if (atomic_dec_and_test(&sig->sigcnt))
 		free_signal_struct(sig);
 }
-
+#ifdef CONFIG_PREEMPT_RT_BASE
+static
+#endif
 void __put_task_struct(struct task_struct *tsk)
 {
 	WARN_ON(!tsk->exit_state);
 	WARN_ON(atomic_read(&tsk->usage));
 	WARN_ON(tsk == current);
 
+	/*
+	 * Remove function-return probe instances associated with this
+	 * task and put them back on the free list.
+	 */
+	kprobe_flush_task(tsk);
+
+	/* Task is done with its stack. */
+	put_task_stack(tsk);
+
 	cgroup_free(tsk);
 	task_numa_free(tsk);
 	security_task_free(tsk);
@@ -688,7 +713,18 @@ void __put_task_struct(struct task_struc
 	if (!profile_handoff_task(tsk))
 		free_task(tsk);
 }
+#ifndef CONFIG_PREEMPT_RT_BASE
 EXPORT_SYMBOL_GPL(__put_task_struct);
+#else
+void __put_task_struct_cb(struct rcu_head *rhp)
+{
+	struct task_struct *tsk = container_of(rhp, struct task_struct, put_rcu);
+
+	__put_task_struct(tsk);
+
+}
+EXPORT_SYMBOL_GPL(__put_task_struct_cb);
+#endif
 
 void __init __weak arch_task_cache_init(void) { }
 
@@ -845,6 +881,8 @@ static struct task_struct *dup_task_stru
 #ifdef CONFIG_STACKPROTECTOR
 	tsk->stack_canary = get_random_canary();
 #endif
+	if (orig->cpus_ptr == &orig->cpus_mask)
+		tsk->cpus_ptr = &tsk->cpus_mask;
 
 	/*
 	 * One for us, one for whoever does the "release_task()" (usually
@@ -857,6 +895,7 @@ static struct task_struct *dup_task_stru
 	tsk->splice_pipe = NULL;
 	tsk->task_frag.page = NULL;
 	tsk->wake_q.next = NULL;
+	tsk->wake_q_sleeper.next = NULL;
 
 	account_kernel_stack(tsk, 1);
 
@@ -1573,6 +1612,9 @@ static void rt_mutex_init_task(struct ta
  */
 static void posix_cpu_timers_init(struct task_struct *tsk)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	tsk->posix_timer_list = NULL;
+#endif
 	tsk->cputime_expires.prof_exp = 0;
 	tsk->cputime_expires.virt_exp = 0;
 	tsk->cputime_expires.sched_exp = 0;
@@ -1760,6 +1802,7 @@ static __latent_entropy struct task_stru
 	spin_lock_init(&p->alloc_lock);
 
 	init_sigpending(&p->pending);
+	p->sigqueue_cache = NULL;
 
 	p->utime = p->stime = p->gtime = 0;
 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
Index: linux-4.19.25-rt16/kernel/futex.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/futex.c
+++ linux-4.19.25-rt16/kernel/futex.c
@@ -918,7 +918,9 @@ void exit_pi_state_list(struct task_stru
 		if (head->next != next) {
 			/* retain curr->pi_lock for the loop invariant */
 			raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
+			raw_spin_unlock_irq(&curr->pi_lock);
 			spin_unlock(&hb->lock);
+			raw_spin_lock_irq(&curr->pi_lock);
 			put_pi_state(pi_state);
 			continue;
 		}
@@ -1472,6 +1474,7 @@ static int wake_futex_pi(u32 __user *uad
 	struct task_struct *new_owner;
 	bool postunlock = false;
 	DEFINE_WAKE_Q(wake_q);
+	DEFINE_WAKE_Q(wake_sleeper_q);
 	int ret = 0;
 
 	new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
@@ -1533,13 +1536,13 @@ static int wake_futex_pi(u32 __user *uad
 	pi_state->owner = new_owner;
 	raw_spin_unlock(&new_owner->pi_lock);
 
-	postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q);
-
+	postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q,
+					     &wake_sleeper_q);
 out_unlock:
 	raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
 
 	if (postunlock)
-		rt_mutex_postunlock(&wake_q);
+		rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
 
 	return ret;
 }
@@ -2146,6 +2149,16 @@ retry_private:
 				requeue_pi_wake_futex(this, &key2, hb2);
 				drop_count++;
 				continue;
+			} else if (ret == -EAGAIN) {
+				/*
+				 * Waiter was woken by timeout or
+				 * signal and has set pi_blocked_on to
+				 * PI_WAKEUP_INPROGRESS before we
+				 * tried to enqueue it on the rtmutex.
+				 */
+				this->pi_state = NULL;
+				put_pi_state(pi_state);
+				continue;
 			} else if (ret) {
 				/*
 				 * rt_mutex_start_proxy_lock() detected a
@@ -2684,10 +2697,9 @@ static int futex_wait(u32 __user *uaddr,
 	if (abs_time) {
 		to = &timeout;
 
-		hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ?
-				      CLOCK_REALTIME : CLOCK_MONOTONIC,
-				      HRTIMER_MODE_ABS);
-		hrtimer_init_sleeper(to, current);
+		hrtimer_init_sleeper_on_stack(to, (flags & FLAGS_CLOCKRT) ?
+					      CLOCK_REALTIME : CLOCK_MONOTONIC,
+					      HRTIMER_MODE_ABS, current);
 		hrtimer_set_expires_range_ns(&to->timer, *abs_time,
 					     current->timer_slack_ns);
 	}
@@ -2786,9 +2798,8 @@ static int futex_lock_pi(u32 __user *uad
 
 	if (time) {
 		to = &timeout;
-		hrtimer_init_on_stack(&to->timer, CLOCK_REALTIME,
-				      HRTIMER_MODE_ABS);
-		hrtimer_init_sleeper(to, current);
+		hrtimer_init_sleeper_on_stack(to, CLOCK_REALTIME,
+					      HRTIMER_MODE_ABS, current);
 		hrtimer_set_expires(&to->timer, *time);
 	}
 
@@ -2843,7 +2854,7 @@ retry_private:
 		goto no_block;
 	}
 
-	rt_mutex_init_waiter(&rt_waiter);
+	rt_mutex_init_waiter(&rt_waiter, false);
 
 	/*
 	 * On PREEMPT_RT_FULL, when hb->lock becomes an rt_mutex, we must not
@@ -2859,6 +2870,14 @@ retry_private:
 	 * before __rt_mutex_start_proxy_lock() is done.
 	 */
 	raw_spin_lock_irq(&q.pi_state->pi_mutex.wait_lock);
+	/*
+	 * the migrate_disable() here disables migration in the in_atomic() fast
+	 * path which is enabled again in the following spin_unlock(). We have
+	 * one migrate_disable() pending in the slow-path which is reversed
+	 * after the raw_spin_unlock_irq() where we leave the atomic context.
+	 */
+	migrate_disable();
+
 	spin_unlock(q.lock_ptr);
 	/*
 	 * __rt_mutex_start_proxy_lock() unconditionally enqueues the @rt_waiter
@@ -2867,6 +2886,7 @@ retry_private:
 	 */
 	ret = __rt_mutex_start_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter, current);
 	raw_spin_unlock_irq(&q.pi_state->pi_mutex.wait_lock);
+	migrate_enable();
 
 	if (ret) {
 		if (ret == 1)
@@ -3015,11 +3035,21 @@ retry:
 		 * rt_waiter. Also see the WARN in wake_futex_pi().
 		 */
 		raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
+		/*
+		 * Magic trickery for now to make the RT migrate disable
+		 * logic happy. The following spin_unlock() happens with
+		 * interrupts disabled so the internal migrate_enable()
+		 * won't undo the migrate_disable() which was issued when
+		 * locking hb->lock.
+		 */
+		migrate_disable();
 		spin_unlock(&hb->lock);
 
 		/* drops pi_state->pi_mutex.wait_lock */
 		ret = wake_futex_pi(uaddr, uval, pi_state);
 
+		migrate_enable();
+
 		put_pi_state(pi_state);
 
 		/*
@@ -3177,7 +3207,7 @@ static int futex_wait_requeue_pi(u32 __u
 	struct hrtimer_sleeper timeout, *to = NULL;
 	struct futex_pi_state *pi_state = NULL;
 	struct rt_mutex_waiter rt_waiter;
-	struct futex_hash_bucket *hb;
+	struct futex_hash_bucket *hb, *hb2;
 	union futex_key key2 = FUTEX_KEY_INIT;
 	struct futex_q q = futex_q_init;
 	int res, ret;
@@ -3193,10 +3223,9 @@ static int futex_wait_requeue_pi(u32 __u
 
 	if (abs_time) {
 		to = &timeout;
-		hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ?
-				      CLOCK_REALTIME : CLOCK_MONOTONIC,
-				      HRTIMER_MODE_ABS);
-		hrtimer_init_sleeper(to, current);
+		hrtimer_init_sleeper_on_stack(to, (flags & FLAGS_CLOCKRT) ?
+					      CLOCK_REALTIME : CLOCK_MONOTONIC,
+					      HRTIMER_MODE_ABS, current);
 		hrtimer_set_expires_range_ns(&to->timer, *abs_time,
 					     current->timer_slack_ns);
 	}
@@ -3205,7 +3234,7 @@ static int futex_wait_requeue_pi(u32 __u
 	 * The waiter is allocated on our stack, manipulated by the requeue
 	 * code while we sleep on uaddr.
 	 */
-	rt_mutex_init_waiter(&rt_waiter);
+	rt_mutex_init_waiter(&rt_waiter, false);
 
 	ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, VERIFY_WRITE);
 	if (unlikely(ret != 0))
@@ -3236,20 +3265,55 @@ static int futex_wait_requeue_pi(u32 __u
 	/* Queue the futex_q, drop the hb lock, wait for wakeup. */
 	futex_wait_queue_me(hb, &q, to);
 
-	spin_lock(&hb->lock);
-	ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
-	spin_unlock(&hb->lock);
-	if (ret)
-		goto out_put_keys;
+	/*
+	 * On RT we must avoid races with requeue and trying to block
+	 * on two mutexes (hb->lock and uaddr2's rtmutex) by
+	 * serializing access to pi_blocked_on with pi_lock.
+	 */
+	raw_spin_lock_irq(&current->pi_lock);
+	if (current->pi_blocked_on) {
+		/*
+		 * We have been requeued or are in the process of
+		 * being requeued.
+		 */
+		raw_spin_unlock_irq(&current->pi_lock);
+	} else {
+		/*
+		 * Setting pi_blocked_on to PI_WAKEUP_INPROGRESS
+		 * prevents a concurrent requeue from moving us to the
+		 * uaddr2 rtmutex. After that we can safely acquire
+		 * (and possibly block on) hb->lock.
+		 */
+		current->pi_blocked_on = PI_WAKEUP_INPROGRESS;
+		raw_spin_unlock_irq(&current->pi_lock);
+
+		spin_lock(&hb->lock);
+
+		/*
+		 * Clean up pi_blocked_on. We might leak it otherwise
+		 * when we succeeded with the hb->lock in the fast
+		 * path.
+		 */
+		raw_spin_lock_irq(&current->pi_lock);
+		current->pi_blocked_on = NULL;
+		raw_spin_unlock_irq(&current->pi_lock);
+
+		ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
+		spin_unlock(&hb->lock);
+		if (ret)
+			goto out_put_keys;
+	}
 
 	/*
-	 * In order for us to be here, we know our q.key == key2, and since
-	 * we took the hb->lock above, we also know that futex_requeue() has
-	 * completed and we no longer have to concern ourselves with a wakeup
-	 * race with the atomic proxy lock acquisition by the requeue code. The
-	 * futex_requeue dropped our key1 reference and incremented our key2
-	 * reference count.
+	 * In order to be here, we have either been requeued, are in
+	 * the process of being requeued, or requeue successfully
+	 * acquired uaddr2 on our behalf.  If pi_blocked_on was
+	 * non-null above, we may be racing with a requeue.  Do not
+	 * rely on q->lock_ptr to be hb2->lock until after blocking on
+	 * hb->lock or hb2->lock. The futex_requeue dropped our key1
+	 * reference and incremented our key2 reference count.
 	 */
+	hb2 = hash_futex(&key2);
 
 	/* Check if the requeue code acquired the second futex for us. */
 	if (!q.rt_waiter) {
@@ -3258,7 +3322,8 @@ static int futex_wait_requeue_pi(u32 __u
 		 * did a lock-steal - fix up the PI-state in that case.
 		 */
 		if (q.pi_state && (q.pi_state->owner != current)) {
-			spin_lock(q.lock_ptr);
+			spin_lock(&hb2->lock);
+			BUG_ON(&hb2->lock != q.lock_ptr);
 			ret = fixup_pi_state_owner(uaddr2, &q, current);
 			if (ret && rt_mutex_owner(&q.pi_state->pi_mutex) == current) {
 				pi_state = q.pi_state;
@@ -3269,7 +3334,7 @@ static int futex_wait_requeue_pi(u32 __u
 			 * the requeue_pi() code acquired for us.
 			 */
 			put_pi_state(q.pi_state);
-			spin_unlock(q.lock_ptr);
+			spin_unlock(&hb2->lock);
 		}
 	} else {
 		struct rt_mutex *pi_mutex;
@@ -3283,7 +3348,8 @@ static int futex_wait_requeue_pi(u32 __u
 		pi_mutex = &q.pi_state->pi_mutex;
 		ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter);
 
-		spin_lock(q.lock_ptr);
+		spin_lock(&hb2->lock);
+		BUG_ON(&hb2->lock != q.lock_ptr);
 		if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter))
 			ret = 0;
 
Index: linux-4.19.25-rt16/kernel/irq/handle.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/irq/handle.c
+++ linux-4.19.25-rt16/kernel/irq/handle.c
@@ -185,10 +185,16 @@ irqreturn_t handle_irq_event_percpu(stru
 {
 	irqreturn_t retval;
 	unsigned int flags = 0;
+	struct pt_regs *regs = get_irq_regs();
+	u64 ip = regs ? instruction_pointer(regs) : 0;
 
 	retval = __handle_irq_event_percpu(desc, &flags);
 
-	add_interrupt_randomness(desc->irq_data.irq, flags);
+#ifdef CONFIG_PREEMPT_RT_FULL
+	desc->random_ip = ip;
+#else
+	add_interrupt_randomness(desc->irq_data.irq, flags, ip);
+#endif
 
 	if (!noirqdebug)
 		note_interrupt(desc, retval);
Index: linux-4.19.25-rt16/kernel/irq/manage.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/irq/manage.c
+++ linux-4.19.25-rt16/kernel/irq/manage.c
@@ -23,6 +23,7 @@
 #include "internals.h"
 
 #ifdef CONFIG_IRQ_FORCED_THREADING
+# ifndef CONFIG_PREEMPT_RT_BASE
 __read_mostly bool force_irqthreads;
 EXPORT_SYMBOL_GPL(force_irqthreads);
 
@@ -32,6 +33,7 @@ static int __init setup_forced_irqthread
 	return 0;
 }
 early_param("threadirqs", setup_forced_irqthreads);
+# endif
 #endif
 
 static void __synchronize_hardirq(struct irq_desc *desc)
@@ -257,7 +259,12 @@ int irq_set_affinity_locked(struct irq_d
 
 	if (desc->affinity_notify) {
 		kref_get(&desc->affinity_notify->kref);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+		swork_queue(&desc->affinity_notify->swork);
+#else
 		schedule_work(&desc->affinity_notify->work);
+#endif
 	}
 	irqd_set(data, IRQD_AFFINITY_SET);
 
@@ -295,10 +302,8 @@ int irq_set_affinity_hint(unsigned int i
 }
 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
 
-static void irq_affinity_notify(struct work_struct *work)
+static void _irq_affinity_notify(struct irq_affinity_notify *notify)
 {
-	struct irq_affinity_notify *notify =
-		container_of(work, struct irq_affinity_notify, work);
 	struct irq_desc *desc = irq_to_desc(notify->irq);
 	cpumask_var_t cpumask;
 	unsigned long flags;
@@ -320,6 +325,35 @@ out:
 	kref_put(&notify->kref, notify->release);
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+static void init_helper_thread(void)
+{
+	static int init_sworker_once;
+
+	if (init_sworker_once)
+		return;
+	if (WARN_ON(swork_get()))
+		return;
+	init_sworker_once = 1;
+}
+
+static void irq_affinity_notify(struct swork_event *swork)
+{
+	struct irq_affinity_notify *notify =
+		container_of(swork, struct irq_affinity_notify, swork);
+	_irq_affinity_notify(notify);
+}
+
+#else
+
+static void irq_affinity_notify(struct work_struct *work)
+{
+	struct irq_affinity_notify *notify =
+		container_of(work, struct irq_affinity_notify, work);
+	_irq_affinity_notify(notify);
+}
+#endif
+
 /**
  *	irq_set_affinity_notifier - control notification of IRQ affinity changes
  *	@irq:		Interrupt for which to enable/disable notification
@@ -348,7 +382,12 @@ irq_set_affinity_notifier(unsigned int i
 	if (notify) {
 		notify->irq = irq;
 		kref_init(&notify->kref);
+#ifdef CONFIG_PREEMPT_RT_BASE
+		INIT_SWORK(&notify->swork, irq_affinity_notify);
+		init_helper_thread();
+#else
 		INIT_WORK(&notify->work, irq_affinity_notify);
+#endif
 	}
 
 	raw_spin_lock_irqsave(&desc->lock, flags);
@@ -934,7 +973,15 @@ irq_forced_thread_fn(struct irq_desc *de
 		atomic_inc(&desc->threads_handled);
 
 	irq_finalize_oneshot(desc, action);
-	local_bh_enable();
+	/*
+	 * Interrupts which have real time requirements can be set up
+	 * to avoid softirq processing in the thread handler. This is
+	 * safe as these interrupts do not raise soft interrupts.
+	 */
+	if (irq_settings_no_softirq_call(desc))
+		_local_bh_enable();
+	else
+		local_bh_enable();
 	return ret;
 }
 
@@ -1032,6 +1079,12 @@ static int irq_thread(void *data)
 		if (action_ret == IRQ_WAKE_THREAD)
 			irq_wake_secondary(desc, action);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+		migrate_disable();
+		add_interrupt_randomness(action->irq, 0,
+				 desc->random_ip ^ (unsigned long) action);
+		migrate_enable();
+#endif
 		wake_threads_waitq(desc);
 	}
 
@@ -1444,6 +1497,9 @@ __setup_irq(unsigned int irq, struct irq
 			irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
 		}
 
+		if (new->flags & IRQF_NO_SOFTIRQ_CALL)
+			irq_settings_set_no_softirq_call(desc);
+
 		if (irq_settings_can_autoenable(desc)) {
 			irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
 		} else {
@@ -2227,7 +2283,7 @@ EXPORT_SYMBOL_GPL(irq_get_irqchip_state)
  *	This call sets the internal irqchip state of an interrupt,
  *	depending on the value of @which.
  *
- *	This function should be called with preemption disabled if the
+ *	This function should be called with migration disabled if the
  *	interrupt controller has per-cpu registers.
  */
 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
Index: linux-4.19.25-rt16/kernel/irq/settings.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/irq/settings.h
+++ linux-4.19.25-rt16/kernel/irq/settings.h
@@ -17,6 +17,7 @@ enum {
 	_IRQ_PER_CPU_DEVID	= IRQ_PER_CPU_DEVID,
 	_IRQ_IS_POLLED		= IRQ_IS_POLLED,
 	_IRQ_DISABLE_UNLAZY	= IRQ_DISABLE_UNLAZY,
+	_IRQ_NO_SOFTIRQ_CALL	= IRQ_NO_SOFTIRQ_CALL,
 	_IRQF_MODIFY_MASK	= IRQF_MODIFY_MASK,
 };
 
@@ -31,6 +32,7 @@ enum {
 #define IRQ_PER_CPU_DEVID	GOT_YOU_MORON
 #define IRQ_IS_POLLED		GOT_YOU_MORON
 #define IRQ_DISABLE_UNLAZY	GOT_YOU_MORON
+#define IRQ_NO_SOFTIRQ_CALL	GOT_YOU_MORON
 #undef IRQF_MODIFY_MASK
 #define IRQF_MODIFY_MASK	GOT_YOU_MORON
 
@@ -41,6 +43,16 @@ irq_settings_clr_and_set(struct irq_desc
 	desc->status_use_accessors |= (set & _IRQF_MODIFY_MASK);
 }
 
+static inline bool irq_settings_no_softirq_call(struct irq_desc *desc)
+{
+	return desc->status_use_accessors & _IRQ_NO_SOFTIRQ_CALL;
+}
+
+static inline void irq_settings_set_no_softirq_call(struct irq_desc *desc)
+{
+	desc->status_use_accessors |= _IRQ_NO_SOFTIRQ_CALL;
+}
+
 static inline bool irq_settings_is_per_cpu(struct irq_desc *desc)
 {
 	return desc->status_use_accessors & _IRQ_PER_CPU;
Index: linux-4.19.25-rt16/kernel/irq/spurious.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/irq/spurious.c
+++ linux-4.19.25-rt16/kernel/irq/spurious.c
@@ -442,6 +442,10 @@ MODULE_PARM_DESC(noirqdebug, "Disable ir
 
 static int __init irqfixup_setup(char *str)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	pr_warn("irqfixup boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+	return 1;
+#endif
 	irqfixup = 1;
 	printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
 	printk(KERN_WARNING "This may impact system performance.\n");
@@ -454,6 +458,10 @@ module_param(irqfixup, int, 0644);
 
 static int __init irqpoll_setup(char *str)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	pr_warn("irqpoll boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+	return 1;
+#endif
 	irqfixup = 2;
 	printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
 				"enabled\n");
Index: linux-4.19.25-rt16/kernel/irq_work.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/irq_work.c
+++ linux-4.19.25-rt16/kernel/irq_work.c
@@ -17,6 +17,7 @@
 #include <linux/cpu.h>
 #include <linux/notifier.h>
 #include <linux/smp.h>
+#include <linux/interrupt.h>
 #include <asm/processor.h>
 
 
@@ -64,6 +65,8 @@ void __weak arch_irq_work_raise(void)
  */
 bool irq_work_queue_on(struct irq_work *work, int cpu)
 {
+	struct llist_head *list;
+
 	/* All work should have been flushed before going offline */
 	WARN_ON_ONCE(cpu_is_offline(cpu));
 
@@ -76,7 +79,12 @@ bool irq_work_queue_on(struct irq_work *
 	if (!irq_work_claim(work))
 		return false;
 
-	if (llist_add(&work->llnode, &per_cpu(raised_list, cpu)))
+	if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL) && !(work->flags & IRQ_WORK_HARD_IRQ))
+		list = &per_cpu(lazy_list, cpu);
+	else
+		list = &per_cpu(raised_list, cpu);
+
+	if (llist_add(&work->llnode, list))
 		arch_send_call_function_single_ipi(cpu);
 
 #else /* #ifdef CONFIG_SMP */
@@ -89,6 +97,9 @@ bool irq_work_queue_on(struct irq_work *
 /* Enqueue the irq work @work on the current CPU */
 bool irq_work_queue(struct irq_work *work)
 {
+	struct llist_head *list;
+	bool lazy_work, realtime = IS_ENABLED(CONFIG_PREEMPT_RT_FULL);
+
 	/* Only queue if not already pending */
 	if (!irq_work_claim(work))
 		return false;
@@ -96,13 +107,15 @@ bool irq_work_queue(struct irq_work *wor
 	/* Queue the entry and raise the IPI if needed. */
 	preempt_disable();
 
-	/* If the work is "lazy", handle it from next tick if any */
-	if (work->flags & IRQ_WORK_LAZY) {
-		if (llist_add(&work->llnode, this_cpu_ptr(&lazy_list)) &&
-		    tick_nohz_tick_stopped())
-			arch_irq_work_raise();
-	} else {
-		if (llist_add(&work->llnode, this_cpu_ptr(&raised_list)))
+	lazy_work = work->flags & IRQ_WORK_LAZY;
+
+	if (lazy_work || (realtime && !(work->flags & IRQ_WORK_HARD_IRQ)))
+		list = this_cpu_ptr(&lazy_list);
+	else
+		list = this_cpu_ptr(&raised_list);
+
+	if (llist_add(&work->llnode, list)) {
+		if (!lazy_work || tick_nohz_tick_stopped())
 			arch_irq_work_raise();
 	}
 
@@ -119,9 +132,8 @@ bool irq_work_needs_cpu(void)
 	raised = this_cpu_ptr(&raised_list);
 	lazy = this_cpu_ptr(&lazy_list);
 
-	if (llist_empty(raised) || arch_irq_work_has_interrupt())
-		if (llist_empty(lazy))
-			return false;
+	if (llist_empty(raised) && llist_empty(lazy))
+		return false;
 
 	/* All work should have been flushed before going offline */
 	WARN_ON_ONCE(cpu_is_offline(smp_processor_id()));
@@ -135,8 +147,12 @@ static void irq_work_run_list(struct lli
 	struct llist_node *llnode;
 	unsigned long flags;
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+	/*
+	 * nort: On RT IRQ-work may run in SOFTIRQ context.
+	 */
 	BUG_ON(!irqs_disabled());
-
+#endif
 	if (llist_empty(list))
 		return;
 
@@ -168,7 +184,16 @@ static void irq_work_run_list(struct lli
 void irq_work_run(void)
 {
 	irq_work_run_list(this_cpu_ptr(&raised_list));
-	irq_work_run_list(this_cpu_ptr(&lazy_list));
+	if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) {
+		/*
+		 * NOTE: we raise softirq via IPI for safety,
+		 * and execute in irq_work_tick() to move the
+		 * overhead from hard to soft irq context.
+		 */
+		if (!llist_empty(this_cpu_ptr(&lazy_list)))
+			raise_softirq(TIMER_SOFTIRQ);
+	} else
+		irq_work_run_list(this_cpu_ptr(&lazy_list));
 }
 EXPORT_SYMBOL_GPL(irq_work_run);
 
@@ -178,8 +203,17 @@ void irq_work_tick(void)
 
 	if (!llist_empty(raised) && !arch_irq_work_has_interrupt())
 		irq_work_run_list(raised);
+
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL))
+		irq_work_run_list(this_cpu_ptr(&lazy_list));
+}
+
+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
+void irq_work_tick_soft(void)
+{
 	irq_work_run_list(this_cpu_ptr(&lazy_list));
 }
+#endif
 
 /*
  * Synchronize against the irq_work @entry, ensures the entry is not
Index: linux-4.19.25-rt16/kernel/ksysfs.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/ksysfs.c
+++ linux-4.19.25-rt16/kernel/ksysfs.c
@@ -140,6 +140,15 @@ KERNEL_ATTR_RO(vmcoreinfo);
 
 #endif /* CONFIG_CRASH_CORE */
 
+#if defined(CONFIG_PREEMPT_RT_FULL)
+static ssize_t realtime_show(struct kobject *kobj,
+			     struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", 1);
+}
+KERNEL_ATTR_RO(realtime);
+#endif
+
 /* whether file capabilities are enabled */
 static ssize_t fscaps_show(struct kobject *kobj,
 				  struct kobj_attribute *attr, char *buf)
@@ -231,6 +240,9 @@ static struct attribute * kernel_attrs[]
 	&rcu_expedited_attr.attr,
 	&rcu_normal_attr.attr,
 #endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+	&realtime_attr.attr,
+#endif
 	NULL
 };
 
Index: linux-4.19.25-rt16/kernel/kthread.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/kthread.c
+++ linux-4.19.25-rt16/kernel/kthread.c
@@ -599,7 +599,7 @@ void __kthread_init_worker(struct kthrea
 				struct lock_class_key *key)
 {
 	memset(worker, 0, sizeof(struct kthread_worker));
-	spin_lock_init(&worker->lock);
+	raw_spin_lock_init(&worker->lock);
 	lockdep_set_class_and_name(&worker->lock, key, name);
 	INIT_LIST_HEAD(&worker->work_list);
 	INIT_LIST_HEAD(&worker->delayed_work_list);
@@ -641,21 +641,21 @@ repeat:
 
 	if (kthread_should_stop()) {
 		__set_current_state(TASK_RUNNING);
-		spin_lock_irq(&worker->lock);
+		raw_spin_lock_irq(&worker->lock);
 		worker->task = NULL;
-		spin_unlock_irq(&worker->lock);
+		raw_spin_unlock_irq(&worker->lock);
 		return 0;
 	}
 
 	work = NULL;
-	spin_lock_irq(&worker->lock);
+	raw_spin_lock_irq(&worker->lock);
 	if (!list_empty(&worker->work_list)) {
 		work = list_first_entry(&worker->work_list,
 					struct kthread_work, node);
 		list_del_init(&work->node);
 	}
 	worker->current_work = work;
-	spin_unlock_irq(&worker->lock);
+	raw_spin_unlock_irq(&worker->lock);
 
 	if (work) {
 		__set_current_state(TASK_RUNNING);
@@ -812,12 +812,12 @@ bool kthread_queue_work(struct kthread_w
 	bool ret = false;
 	unsigned long flags;
 
-	spin_lock_irqsave(&worker->lock, flags);
+	raw_spin_lock_irqsave(&worker->lock, flags);
 	if (!queuing_blocked(worker, work)) {
 		kthread_insert_work(worker, work, &worker->work_list);
 		ret = true;
 	}
-	spin_unlock_irqrestore(&worker->lock, flags);
+	raw_spin_unlock_irqrestore(&worker->lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(kthread_queue_work);
@@ -843,7 +843,7 @@ void kthread_delayed_work_timer_fn(struc
 	if (WARN_ON_ONCE(!worker))
 		return;
 
-	spin_lock(&worker->lock);
+	raw_spin_lock(&worker->lock);
 	/* Work must not be used with >1 worker, see kthread_queue_work(). */
 	WARN_ON_ONCE(work->worker != worker);
 
@@ -852,7 +852,7 @@ void kthread_delayed_work_timer_fn(struc
 	list_del_init(&work->node);
 	kthread_insert_work(worker, work, &worker->work_list);
 
-	spin_unlock(&worker->lock);
+	raw_spin_unlock(&worker->lock);
 }
 EXPORT_SYMBOL(kthread_delayed_work_timer_fn);
 
@@ -908,14 +908,14 @@ bool kthread_queue_delayed_work(struct k
 	unsigned long flags;
 	bool ret = false;
 
-	spin_lock_irqsave(&worker->lock, flags);
+	raw_spin_lock_irqsave(&worker->lock, flags);
 
 	if (!queuing_blocked(worker, work)) {
 		__kthread_queue_delayed_work(worker, dwork, delay);
 		ret = true;
 	}
 
-	spin_unlock_irqrestore(&worker->lock, flags);
+	raw_spin_unlock_irqrestore(&worker->lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(kthread_queue_delayed_work);
@@ -951,7 +951,7 @@ void kthread_flush_work(struct kthread_w
 	if (!worker)
 		return;
 
-	spin_lock_irq(&worker->lock);
+	raw_spin_lock_irq(&worker->lock);
 	/* Work must not be used with >1 worker, see kthread_queue_work(). */
 	WARN_ON_ONCE(work->worker != worker);
 
@@ -963,7 +963,7 @@ void kthread_flush_work(struct kthread_w
 	else
 		noop = true;
 
-	spin_unlock_irq(&worker->lock);
+	raw_spin_unlock_irq(&worker->lock);
 
 	if (!noop)
 		wait_for_completion(&fwork.done);
@@ -996,9 +996,9 @@ static bool __kthread_cancel_work(struct
 		 * any queuing is blocked by setting the canceling counter.
 		 */
 		work->canceling++;
-		spin_unlock_irqrestore(&worker->lock, *flags);
+		raw_spin_unlock_irqrestore(&worker->lock, *flags);
 		del_timer_sync(&dwork->timer);
-		spin_lock_irqsave(&worker->lock, *flags);
+		raw_spin_lock_irqsave(&worker->lock, *flags);
 		work->canceling--;
 	}
 
@@ -1045,7 +1045,7 @@ bool kthread_mod_delayed_work(struct kth
 	unsigned long flags;
 	int ret = false;
 
-	spin_lock_irqsave(&worker->lock, flags);
+	raw_spin_lock_irqsave(&worker->lock, flags);
 
 	/* Do not bother with canceling when never queued. */
 	if (!work->worker)
@@ -1062,7 +1062,7 @@ bool kthread_mod_delayed_work(struct kth
 fast_queue:
 	__kthread_queue_delayed_work(worker, dwork, delay);
 out:
-	spin_unlock_irqrestore(&worker->lock, flags);
+	raw_spin_unlock_irqrestore(&worker->lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(kthread_mod_delayed_work);
@@ -1076,7 +1076,7 @@ static bool __kthread_cancel_work_sync(s
 	if (!worker)
 		goto out;
 
-	spin_lock_irqsave(&worker->lock, flags);
+	raw_spin_lock_irqsave(&worker->lock, flags);
 	/* Work must not be used with >1 worker, see kthread_queue_work(). */
 	WARN_ON_ONCE(work->worker != worker);
 
@@ -1090,13 +1090,13 @@ static bool __kthread_cancel_work_sync(s
 	 * In the meantime, block any queuing by setting the canceling counter.
 	 */
 	work->canceling++;
-	spin_unlock_irqrestore(&worker->lock, flags);
+	raw_spin_unlock_irqrestore(&worker->lock, flags);
 	kthread_flush_work(work);
-	spin_lock_irqsave(&worker->lock, flags);
+	raw_spin_lock_irqsave(&worker->lock, flags);
 	work->canceling--;
 
 out_fast:
-	spin_unlock_irqrestore(&worker->lock, flags);
+	raw_spin_unlock_irqrestore(&worker->lock, flags);
 out:
 	return ret;
 }
Index: linux-4.19.25-rt16/kernel/locking/Makefile
===================================================================
--- linux-4.19.25-rt16.orig/kernel/locking/Makefile
+++ linux-4.19.25-rt16/kernel/locking/Makefile
@@ -3,7 +3,7 @@
 # and is generally not a function of system call inputs.
 KCOV_INSTRUMENT		:= n
 
-obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o
+obj-y += semaphore.o percpu-rwsem.o
 
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)
@@ -12,7 +12,11 @@ CFLAGS_REMOVE_mutex-debug.o = $(CC_FLAGS
 CFLAGS_REMOVE_rtmutex-debug.o = $(CC_FLAGS_FTRACE)
 endif
 
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
+obj-y += mutex.o
 obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
+endif
+obj-y += rwsem.o
 obj-$(CONFIG_LOCKDEP) += lockdep.o
 ifeq ($(CONFIG_PROC_FS),y)
 obj-$(CONFIG_LOCKDEP) += lockdep_proc.o
@@ -25,8 +29,11 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
 obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
 obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
 obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o
+endif
+obj-$(CONFIG_PREEMPT_RT_FULL) += mutex-rt.o rwsem-rt.o rwlock-rt.o
 obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o
 obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o
 obj-$(CONFIG_WW_MUTEX_SELFTEST) += test-ww_mutex.o
Index: linux-4.19.25-rt16/kernel/locking/lockdep.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/locking/lockdep.c
+++ linux-4.19.25-rt16/kernel/locking/lockdep.c
@@ -3823,6 +3823,7 @@ static void check_flags(unsigned long fl
 		}
 	}
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 	/*
 	 * We dont accurately track softirq state in e.g.
 	 * hardirq contexts (such as on 4KSTACKS), so only
@@ -3837,6 +3838,7 @@ static void check_flags(unsigned long fl
 			DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
 		}
 	}
+#endif
 
 	if (!debug_locks)
 		print_irqtrace_events(current);
Index: linux-4.19.25-rt16/kernel/locking/locktorture.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/locking/locktorture.c
+++ linux-4.19.25-rt16/kernel/locking/locktorture.c
@@ -29,7 +29,6 @@
 #include <linux/kthread.h>
 #include <linux/sched/rt.h>
 #include <linux/spinlock.h>
-#include <linux/rwlock.h>
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
 #include <linux/smp.h>
Index: linux-4.19.25-rt16/kernel/locking/mutex-rt.c
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/kernel/locking/mutex-rt.c
@@ -0,0 +1,223 @@
+/*
+ * kernel/rt.c
+ *
+ * Real-Time Preemption Support
+ *
+ * started by Ingo Molnar:
+ *
+ *  Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * historic credit for proving that Linux spinlocks can be implemented via
+ * RT-aware mutexes goes to many people: The Pmutex project (Dirk Grambow
+ * and others) who prototyped it on 2.4 and did lots of comparative
+ * research and analysis; TimeSys, for proving that you can implement a
+ * fully preemptible kernel via the use of IRQ threading and mutexes;
+ * Bill Huey for persuasively arguing on lkml that the mutex model is the
+ * right one; and to MontaVista, who ported pmutexes to 2.6.
+ *
+ * This code is a from-scratch implementation and is not based on pmutexes,
+ * but the idea of converting spinlocks to mutexes is used here too.
+ *
+ * lock debugging, locking tree, deadlock detection:
+ *
+ *  Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
+ *  Released under the General Public License (GPL).
+ *
+ * Includes portions of the generic R/W semaphore implementation from:
+ *
+ *  Copyright (c) 2001   David Howells (dhowells@redhat.com).
+ *  - Derived partially from idea by Andrea Arcangeli <andrea@suse.de>
+ *  - Derived also from comments by Linus
+ *
+ * Pending ownership of locks and ownership stealing:
+ *
+ *  Copyright (C) 2005, Kihon Technologies Inc., Steven Rostedt
+ *
+ *   (also by Steven Rostedt)
+ *    - Converted single pi_lock to individual task locks.
+ *
+ * By Esben Nielsen:
+ *    Doing priority inheritance with help of the scheduler.
+ *
+ *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *  - major rework based on Esben Nielsens initial patch
+ *  - replaced thread_info references by task_struct refs
+ *  - removed task->pending_owner dependency
+ *  - BKL drop/reacquire for semaphore style locks to avoid deadlocks
+ *    in the scheduler return path as discussed with Steven Rostedt
+ *
+ *  Copyright (C) 2006, Kihon Technologies Inc.
+ *    Steven Rostedt <rostedt@goodmis.org>
+ *  - debugged and patched Thomas Gleixner's rework.
+ *  - added back the cmpxchg to the rework.
+ *  - turned atomic require back on for SMP.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/rtmutex.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/syscalls.h>
+#include <linux/interrupt.h>
+#include <linux/plist.h>
+#include <linux/fs.h>
+#include <linux/futex.h>
+#include <linux/hrtimer.h>
+
+#include "rtmutex_common.h"
+
+/*
+ * struct mutex functions
+ */
+void __mutex_do_init(struct mutex *mutex, const char *name,
+		     struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held lock:
+	 */
+	debug_check_no_locks_freed((void *)mutex, sizeof(*mutex));
+	lockdep_init_map(&mutex->dep_map, name, key, 0);
+#endif
+	mutex->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__mutex_do_init);
+
+void __lockfunc _mutex_lock(struct mutex *lock)
+{
+	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+	__rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(_mutex_lock);
+
+void __lockfunc _mutex_lock_io(struct mutex *lock)
+{
+	int token;
+
+	token = io_schedule_prepare();
+	_mutex_lock(lock);
+	io_schedule_finish(token);
+}
+EXPORT_SYMBOL_GPL(_mutex_lock_io);
+
+int __lockfunc _mutex_lock_interruptible(struct mutex *lock)
+{
+	int ret;
+
+	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+	ret = __rt_mutex_lock_state(&lock->lock, TASK_INTERRUPTIBLE);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible);
+
+int __lockfunc _mutex_lock_killable(struct mutex *lock)
+{
+	int ret;
+
+	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+	ret = __rt_mutex_lock_state(&lock->lock, TASK_KILLABLE);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass)
+{
+	mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+	__rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(_mutex_lock_nested);
+
+void __lockfunc _mutex_lock_io_nested(struct mutex *lock, int subclass)
+{
+	int token;
+
+	token = io_schedule_prepare();
+
+	mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+	__rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE);
+
+	io_schedule_finish(token);
+}
+EXPORT_SYMBOL_GPL(_mutex_lock_io_nested);
+
+void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
+{
+	mutex_acquire_nest(&lock->dep_map, 0, 0, nest, _RET_IP_);
+	__rt_mutex_lock_state(&lock->lock, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(_mutex_lock_nest_lock);
+
+int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass)
+{
+	int ret;
+
+	mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+	ret = __rt_mutex_lock_state(&lock->lock, TASK_INTERRUPTIBLE);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible_nested);
+
+int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass)
+{
+	int ret;
+
+	mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+	ret = __rt_mutex_lock_state(&lock->lock, TASK_KILLABLE);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable_nested);
+#endif
+
+int __lockfunc _mutex_trylock(struct mutex *lock)
+{
+	int ret = __rt_mutex_trylock(&lock->lock);
+
+	if (ret)
+		mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_trylock);
+
+void __lockfunc _mutex_unlock(struct mutex *lock)
+{
+	mutex_release(&lock->dep_map, 1, _RET_IP_);
+	__rt_mutex_unlock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_unlock);
+
+/**
+ * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
+ * @cnt: the atomic which we are to dec
+ * @lock: the mutex to return holding if we dec to 0
+ *
+ * return true and hold lock if we dec to 0, return false otherwise
+ */
+int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
+{
+	/* dec if we can't possibly hit 0 */
+	if (atomic_add_unless(cnt, -1, 1))
+		return 0;
+	/* we might hit 0, so take the lock */
+	mutex_lock(lock);
+	if (!atomic_dec_and_test(cnt)) {
+		/* when we actually did the dec, we didn't hit 0 */
+		mutex_unlock(lock);
+		return 0;
+	}
+	/* we hit 0, and we hold the lock */
+	return 1;
+}
+EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
Index: linux-4.19.25-rt16/kernel/locking/rtmutex.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/locking/rtmutex.c
+++ linux-4.19.25-rt16/kernel/locking/rtmutex.c
@@ -7,6 +7,11 @@
  *  Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
  *  Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
  *  Copyright (C) 2006 Esben Nielsen
+ *  Adaptive Spinlocks:
+ *  Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich,
+ *				     and Peter Morreale,
+ * Adaptive Spinlocks simplification:
+ *  Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com>
  *
  *  See Documentation/locking/rt-mutex-design.txt for details.
  */
@@ -18,6 +23,8 @@
 #include <linux/sched/wake_q.h>
 #include <linux/sched/debug.h>
 #include <linux/timer.h>
+#include <linux/ww_mutex.h>
+#include <linux/blkdev.h>
 
 #include "rtmutex_common.h"
 
@@ -135,6 +142,12 @@ static void fixup_rt_mutex_waiters(struc
 		WRITE_ONCE(*p, owner & ~RT_MUTEX_HAS_WAITERS);
 }
 
+static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter)
+{
+	return waiter && waiter != PI_WAKEUP_INPROGRESS &&
+		waiter != PI_REQUEUE_INPROGRESS;
+}
+
 /*
  * We can speed up the acquire/release, if there's no debugging state to be
  * set up.
@@ -228,7 +241,7 @@ static inline bool unlock_rt_mutex_safe(
  * Only use with rt_mutex_waiter_{less,equal}()
  */
 #define task_to_waiter(p)	\
-	&(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline }
+	&(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline, .task = (p) }
 
 static inline int
 rt_mutex_waiter_less(struct rt_mutex_waiter *left,
@@ -268,6 +281,27 @@ rt_mutex_waiter_equal(struct rt_mutex_wa
 	return 1;
 }
 
+#define STEAL_NORMAL  0
+#define STEAL_LATERAL 1
+
+static inline int
+rt_mutex_steal(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, int mode)
+{
+	struct rt_mutex_waiter *top_waiter = rt_mutex_top_waiter(lock);
+
+	if (waiter == top_waiter || rt_mutex_waiter_less(waiter, top_waiter))
+		return 1;
+
+	/*
+	 * Note that RT tasks are excluded from lateral-steals
+	 * to prevent the introduction of an unbounded latency.
+	 */
+	if (mode == STEAL_NORMAL || rt_task(waiter->task))
+		return 0;
+
+	return rt_mutex_waiter_equal(waiter, top_waiter);
+}
+
 static void
 rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
 {
@@ -372,6 +406,14 @@ static bool rt_mutex_cond_detect_deadloc
 	return debug_rt_mutex_detect_deadlock(waiter, chwalk);
 }
 
+static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter)
+{
+	if (waiter->savestate)
+		wake_up_lock_sleeper(waiter->task);
+	else
+		wake_up_process(waiter->task);
+}
+
 /*
  * Max number of times we'll walk the boosting chain:
  */
@@ -379,7 +421,8 @@ int max_lock_depth = 1024;
 
 static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
 {
-	return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL;
+	return rt_mutex_real_waiter(p->pi_blocked_on) ?
+		p->pi_blocked_on->lock : NULL;
 }
 
 /*
@@ -515,7 +558,7 @@ static int rt_mutex_adjust_prio_chain(st
 	 * reached or the state of the chain has changed while we
 	 * dropped the locks.
 	 */
-	if (!waiter)
+	if (!rt_mutex_real_waiter(waiter))
 		goto out_unlock_pi;
 
 	/*
@@ -696,13 +739,16 @@ static int rt_mutex_adjust_prio_chain(st
 	 * follow here. This is the end of the chain we are walking.
 	 */
 	if (!rt_mutex_owner(lock)) {
+		struct rt_mutex_waiter *lock_top_waiter;
+
 		/*
 		 * If the requeue [7] above changed the top waiter,
 		 * then we need to wake the new top waiter up to try
 		 * to get the lock.
 		 */
-		if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
-			wake_up_process(rt_mutex_top_waiter(lock)->task);
+		lock_top_waiter = rt_mutex_top_waiter(lock);
+		if (prerequeue_top_waiter != lock_top_waiter)
+			rt_mutex_wake_waiter(lock_top_waiter);
 		raw_spin_unlock_irq(&lock->wait_lock);
 		return 0;
 	}
@@ -804,9 +850,11 @@ static int rt_mutex_adjust_prio_chain(st
  * @task:   The task which wants to acquire the lock
  * @waiter: The waiter that is queued to the lock's wait tree if the
  *	    callsite called task_blocked_on_lock(), otherwise NULL
+ * @mode:   Lock steal mode (STEAL_NORMAL, STEAL_LATERAL)
  */
-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
-				struct rt_mutex_waiter *waiter)
+static int __try_to_take_rt_mutex(struct rt_mutex *lock,
+				  struct task_struct *task,
+				  struct rt_mutex_waiter *waiter, int mode)
 {
 	lockdep_assert_held(&lock->wait_lock);
 
@@ -842,12 +890,11 @@ static int try_to_take_rt_mutex(struct r
 	 */
 	if (waiter) {
 		/*
-		 * If waiter is not the highest priority waiter of
-		 * @lock, give up.
+		 * If waiter is not the highest priority waiter of @lock,
+		 * or its peer when lateral steal is allowed, give up.
 		 */
-		if (waiter != rt_mutex_top_waiter(lock))
+		if (!rt_mutex_steal(lock, waiter, mode))
 			return 0;
-
 		/*
 		 * We can acquire the lock. Remove the waiter from the
 		 * lock waiters tree.
@@ -865,14 +912,12 @@ static int try_to_take_rt_mutex(struct r
 		 */
 		if (rt_mutex_has_waiters(lock)) {
 			/*
-			 * If @task->prio is greater than or equal to
-			 * the top waiter priority (kernel view),
-			 * @task lost.
+			 * If @task->prio is greater than the top waiter
+			 * priority (kernel view), or equal to it when a
+			 * lateral steal is forbidden, @task lost.
 			 */
-			if (!rt_mutex_waiter_less(task_to_waiter(task),
-						  rt_mutex_top_waiter(lock)))
+			if (!rt_mutex_steal(lock, task_to_waiter(task), mode))
 				return 0;
-
 			/*
 			 * The current top waiter stays enqueued. We
 			 * don't have to change anything in the lock
@@ -919,6 +964,338 @@ takeit:
 	return 1;
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * preemptible spin_lock functions:
+ */
+static inline void rt_spin_lock_fastlock(struct rt_mutex *lock,
+					 void  (*slowfn)(struct rt_mutex *lock))
+{
+	might_sleep_no_state_check();
+
+	if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
+		return;
+	else
+		slowfn(lock);
+}
+
+static inline void rt_spin_lock_fastunlock(struct rt_mutex *lock,
+					   void  (*slowfn)(struct rt_mutex *lock))
+{
+	if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
+		return;
+	else
+		slowfn(lock);
+}
+#ifdef CONFIG_SMP
+/*
+ * Note that owner is a speculative pointer and dereferencing relies
+ * on rcu_read_lock() and the check against the lock owner.
+ */
+static int adaptive_wait(struct rt_mutex *lock,
+			 struct task_struct *owner)
+{
+	int res = 0;
+
+	rcu_read_lock();
+	for (;;) {
+		if (owner != rt_mutex_owner(lock))
+			break;
+		/*
+		 * Ensure that owner->on_cpu is dereferenced _after_
+		 * checking the above to be valid.
+		 */
+		barrier();
+		if (!owner->on_cpu) {
+			res = 1;
+			break;
+		}
+		cpu_relax();
+	}
+	rcu_read_unlock();
+	return res;
+}
+#else
+static int adaptive_wait(struct rt_mutex *lock,
+			 struct task_struct *orig_owner)
+{
+	return 1;
+}
+#endif
+
+static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+				   struct rt_mutex_waiter *waiter,
+				   struct task_struct *task,
+				   enum rtmutex_chainwalk chwalk);
+/*
+ * Slow path lock function spin_lock style: this variant is very
+ * careful not to miss any non-lock wakeups.
+ *
+ * We store the current state under p->pi_lock in p->saved_state and
+ * the try_to_wake_up() code handles this accordingly.
+ */
+void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock,
+					  struct rt_mutex_waiter *waiter,
+					  unsigned long flags)
+{
+	struct task_struct *lock_owner, *self = current;
+	struct rt_mutex_waiter *top_waiter;
+	int ret;
+
+	if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL))
+		return;
+
+	BUG_ON(rt_mutex_owner(lock) == self);
+
+	/*
+	 * We save whatever state the task is in and we'll restore it
+	 * after acquiring the lock taking real wakeups into account
+	 * as well. We are serialized via pi_lock against wakeups. See
+	 * try_to_wake_up().
+	 */
+	raw_spin_lock(&self->pi_lock);
+	self->saved_state = self->state;
+	__set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+	raw_spin_unlock(&self->pi_lock);
+
+	ret = task_blocks_on_rt_mutex(lock, waiter, self, RT_MUTEX_MIN_CHAINWALK);
+	BUG_ON(ret);
+
+	for (;;) {
+		/* Try to acquire the lock again. */
+		if (__try_to_take_rt_mutex(lock, self, waiter, STEAL_LATERAL))
+			break;
+
+		top_waiter = rt_mutex_top_waiter(lock);
+		lock_owner = rt_mutex_owner(lock);
+
+		raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+
+		debug_rt_mutex_print_deadlock(waiter);
+
+		if (top_waiter != waiter || adaptive_wait(lock, lock_owner))
+			schedule();
+
+		raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+		raw_spin_lock(&self->pi_lock);
+		__set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+		raw_spin_unlock(&self->pi_lock);
+	}
+
+	/*
+	 * Restore the task state to current->saved_state. We set it
+	 * to the original state above and the try_to_wake_up() code
+	 * has possibly updated it when a real (non-rtmutex) wakeup
+	 * happened while we were blocked. Clear saved_state so
+	 * try_to_wakeup() does not get confused.
+	 */
+	raw_spin_lock(&self->pi_lock);
+	__set_current_state_no_track(self->saved_state);
+	self->saved_state = TASK_RUNNING;
+	raw_spin_unlock(&self->pi_lock);
+
+	/*
+	 * try_to_take_rt_mutex() sets the waiter bit
+	 * unconditionally. We might have to fix that up:
+	 */
+	fixup_rt_mutex_waiters(lock);
+
+	BUG_ON(rt_mutex_has_waiters(lock) && waiter == rt_mutex_top_waiter(lock));
+	BUG_ON(!RB_EMPTY_NODE(&waiter->tree_entry));
+}
+
+static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
+{
+	struct rt_mutex_waiter waiter;
+	unsigned long flags;
+
+	rt_mutex_init_waiter(&waiter, true);
+
+	raw_spin_lock_irqsave(&lock->wait_lock, flags);
+	rt_spin_lock_slowlock_locked(lock, &waiter, flags);
+	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+	debug_rt_mutex_free_waiter(&waiter);
+}
+
+static bool __sched __rt_mutex_unlock_common(struct rt_mutex *lock,
+					     struct wake_q_head *wake_q,
+					     struct wake_q_head *wq_sleeper);
+/*
+ * Slow path to release a rt_mutex spin_lock style
+ */
+void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+	unsigned long flags;
+	DEFINE_WAKE_Q(wake_q);
+	DEFINE_WAKE_Q(wake_sleeper_q);
+	bool postunlock;
+
+	raw_spin_lock_irqsave(&lock->wait_lock, flags);
+	postunlock = __rt_mutex_unlock_common(lock, &wake_q, &wake_sleeper_q);
+	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+
+	if (postunlock)
+		rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
+}
+
+void __lockfunc rt_spin_lock(spinlock_t *lock)
+{
+	sleeping_lock_inc();
+	migrate_disable();
+	spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+	rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+}
+EXPORT_SYMBOL(rt_spin_lock);
+
+void __lockfunc __rt_spin_lock(struct rt_mutex *lock)
+{
+	rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock);
+}
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
+{
+	sleeping_lock_inc();
+	migrate_disable();
+	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+	rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+}
+EXPORT_SYMBOL(rt_spin_lock_nested);
+#endif
+
+void __lockfunc rt_spin_unlock(spinlock_t *lock)
+{
+	/* NOTE: we always pass in '1' for nested, for simplicity */
+	spin_release(&lock->dep_map, 1, _RET_IP_);
+	rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
+	migrate_enable();
+	sleeping_lock_dec();
+}
+EXPORT_SYMBOL(rt_spin_unlock);
+
+void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
+{
+	rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(__rt_spin_unlock);
+
+/*
+ * Wait for the lock to get unlocked: instead of polling for an unlock
+ * (like raw spinlocks do), we lock and unlock, to force the kernel to
+ * schedule if there's contention:
+ */
+void __lockfunc rt_spin_unlock_wait(spinlock_t *lock)
+{
+	spin_lock(lock);
+	spin_unlock(lock);
+}
+EXPORT_SYMBOL(rt_spin_unlock_wait);
+
+int __lockfunc rt_spin_trylock(spinlock_t *lock)
+{
+	int ret;
+
+	sleeping_lock_inc();
+	migrate_disable();
+	ret = __rt_mutex_trylock(&lock->lock);
+	if (ret) {
+		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+	} else {
+		migrate_enable();
+		sleeping_lock_dec();
+	}
+	return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock);
+
+int __lockfunc rt_spin_trylock_bh(spinlock_t *lock)
+{
+	int ret;
+
+	local_bh_disable();
+	ret = __rt_mutex_trylock(&lock->lock);
+	if (ret) {
+		sleeping_lock_inc();
+		migrate_disable();
+		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+	} else
+		local_bh_enable();
+	return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_bh);
+
+int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
+{
+	int ret;
+
+	*flags = 0;
+	ret = __rt_mutex_trylock(&lock->lock);
+	if (ret) {
+		sleeping_lock_inc();
+		migrate_disable();
+		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_irqsave);
+
+void
+__rt_spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held lock:
+	 */
+	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+	lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
+}
+EXPORT_SYMBOL(__rt_spin_lock_init);
+
+#endif /* PREEMPT_RT_FULL */
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+	static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+	struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+	struct ww_acquire_ctx *hold_ctx = READ_ONCE(ww->ctx);
+
+	if (!hold_ctx)
+		return 0;
+
+	if (unlikely(ctx == hold_ctx))
+		return -EALREADY;
+
+	if (ctx->stamp - hold_ctx->stamp <= LONG_MAX &&
+	    (ctx->stamp != hold_ctx->stamp || ctx > hold_ctx)) {
+#ifdef CONFIG_DEBUG_MUTEXES
+		DEBUG_LOCKS_WARN_ON(ctx->contending_lock);
+		ctx->contending_lock = ww;
+#endif
+		return -EDEADLK;
+	}
+
+	return 0;
+}
+#else
+	static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+	BUG();
+	return 0;
+}
+
+#endif
+
+static inline int
+try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+		     struct rt_mutex_waiter *waiter)
+{
+	return __try_to_take_rt_mutex(lock, task, waiter, STEAL_NORMAL);
+}
+
 /*
  * Task blocks on lock.
  *
@@ -951,6 +1328,22 @@ static int task_blocks_on_rt_mutex(struc
 		return -EDEADLK;
 
 	raw_spin_lock(&task->pi_lock);
+	/*
+	 * In the case of futex requeue PI, this will be a proxy
+	 * lock. The task will wake unaware that it is enqueueed on
+	 * this lock. Avoid blocking on two locks and corrupting
+	 * pi_blocked_on via the PI_WAKEUP_INPROGRESS
+	 * flag. futex_wait_requeue_pi() sets this when it wakes up
+	 * before requeue (due to a signal or timeout). Do not enqueue
+	 * the task if PI_WAKEUP_INPROGRESS is set.
+	 */
+	if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) {
+		raw_spin_unlock(&task->pi_lock);
+		return -EAGAIN;
+	}
+
+       BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on));
+
 	waiter->task = task;
 	waiter->lock = lock;
 	waiter->prio = task->prio;
@@ -974,7 +1367,7 @@ static int task_blocks_on_rt_mutex(struc
 		rt_mutex_enqueue_pi(owner, waiter);
 
 		rt_mutex_adjust_prio(owner);
-		if (owner->pi_blocked_on)
+		if (rt_mutex_real_waiter(owner->pi_blocked_on))
 			chain_walk = 1;
 	} else if (rt_mutex_cond_detect_deadlock(waiter, chwalk)) {
 		chain_walk = 1;
@@ -1016,6 +1409,7 @@ static int task_blocks_on_rt_mutex(struc
  * Called with lock->wait_lock held and interrupts disabled.
  */
 static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
+				    struct wake_q_head *wake_sleeper_q,
 				    struct rt_mutex *lock)
 {
 	struct rt_mutex_waiter *waiter;
@@ -1055,7 +1449,10 @@ static void mark_wakeup_next_waiter(stru
 	 * Pairs with preempt_enable() in rt_mutex_postunlock();
 	 */
 	preempt_disable();
-	wake_q_add(wake_q, waiter->task);
+	if (waiter->savestate)
+		wake_q_add_sleeper(wake_sleeper_q, waiter->task);
+	else
+		wake_q_add(wake_q, waiter->task);
 	raw_spin_unlock(&current->pi_lock);
 }
 
@@ -1070,7 +1467,7 @@ static void remove_waiter(struct rt_mute
 {
 	bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock));
 	struct task_struct *owner = rt_mutex_owner(lock);
-	struct rt_mutex *next_lock;
+	struct rt_mutex *next_lock = NULL;
 
 	lockdep_assert_held(&lock->wait_lock);
 
@@ -1096,7 +1493,8 @@ static void remove_waiter(struct rt_mute
 	rt_mutex_adjust_prio(owner);
 
 	/* Store the lock on which owner is blocked or NULL */
-	next_lock = task_blocked_on_lock(owner);
+	if (rt_mutex_real_waiter(owner->pi_blocked_on))
+		next_lock = task_blocked_on_lock(owner);
 
 	raw_spin_unlock(&owner->pi_lock);
 
@@ -1132,26 +1530,28 @@ void rt_mutex_adjust_pi(struct task_stru
 	raw_spin_lock_irqsave(&task->pi_lock, flags);
 
 	waiter = task->pi_blocked_on;
-	if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) {
+	if (!rt_mutex_real_waiter(waiter) ||
+	    rt_mutex_waiter_equal(waiter, task_to_waiter(task))) {
 		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 		return;
 	}
 	next_lock = waiter->lock;
-	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 
 	/* gets dropped in rt_mutex_adjust_prio_chain()! */
 	get_task_struct(task);
 
+	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 	rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL,
 				   next_lock, NULL, task);
 }
 
-void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
+void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savestate)
 {
 	debug_rt_mutex_init_waiter(waiter);
 	RB_CLEAR_NODE(&waiter->pi_tree_entry);
 	RB_CLEAR_NODE(&waiter->tree_entry);
 	waiter->task = NULL;
+	waiter->savestate = savestate;
 }
 
 /**
@@ -1167,7 +1567,8 @@ void rt_mutex_init_waiter(struct rt_mute
 static int __sched
 __rt_mutex_slowlock(struct rt_mutex *lock, int state,
 		    struct hrtimer_sleeper *timeout,
-		    struct rt_mutex_waiter *waiter)
+		    struct rt_mutex_waiter *waiter,
+		    struct ww_acquire_ctx *ww_ctx)
 {
 	int ret = 0;
 
@@ -1176,16 +1577,17 @@ __rt_mutex_slowlock(struct rt_mutex *loc
 		if (try_to_take_rt_mutex(lock, current, waiter))
 			break;
 
-		/*
-		 * TASK_INTERRUPTIBLE checks for signals and
-		 * timeout. Ignored otherwise.
-		 */
-		if (likely(state == TASK_INTERRUPTIBLE)) {
-			/* Signal pending? */
-			if (signal_pending(current))
-				ret = -EINTR;
-			if (timeout && !timeout->task)
-				ret = -ETIMEDOUT;
+		if (timeout && !timeout->task) {
+			ret = -ETIMEDOUT;
+			break;
+		}
+		if (signal_pending_state(state, current)) {
+			ret = -EINTR;
+			break;
+		}
+
+		if (ww_ctx && ww_ctx->acquired > 0) {
+			ret = __mutex_lock_check_stamp(lock, ww_ctx);
 			if (ret)
 				break;
 		}
@@ -1224,33 +1626,104 @@ static void rt_mutex_handle_deadlock(int
 	}
 }
 
-/*
- * Slow path lock function:
- */
-static int __sched
-rt_mutex_slowlock(struct rt_mutex *lock, int state,
-		  struct hrtimer_sleeper *timeout,
-		  enum rtmutex_chainwalk chwalk)
+static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww,
+						   struct ww_acquire_ctx *ww_ctx)
 {
-	struct rt_mutex_waiter waiter;
-	unsigned long flags;
-	int ret = 0;
+#ifdef CONFIG_DEBUG_MUTEXES
+	/*
+	 * If this WARN_ON triggers, you used ww_mutex_lock to acquire,
+	 * but released with a normal mutex_unlock in this call.
+	 *
+	 * This should never happen, always use ww_mutex_unlock.
+	 */
+	DEBUG_LOCKS_WARN_ON(ww->ctx);
+
+	/*
+	 * Not quite done after calling ww_acquire_done() ?
+	 */
+	DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire);
 
-	rt_mutex_init_waiter(&waiter);
+	if (ww_ctx->contending_lock) {
+		/*
+		 * After -EDEADLK you tried to
+		 * acquire a different ww_mutex? Bad!
+		 */
+		DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww);
+
+		/*
+		 * You called ww_mutex_lock after receiving -EDEADLK,
+		 * but 'forgot' to unlock everything else first?
+		 */
+		DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0);
+		ww_ctx->contending_lock = NULL;
+	}
 
 	/*
-	 * Technically we could use raw_spin_[un]lock_irq() here, but this can
-	 * be called in early boot if the cmpxchg() fast path is disabled
-	 * (debug, no architecture support). In this case we will acquire the
-	 * rtmutex with lock->wait_lock held. But we cannot unconditionally
-	 * enable interrupts in that early boot case. So we need to use the
-	 * irqsave/restore variants.
+	 * Naughty, using a different class will lead to undefined behavior!
 	 */
-	raw_spin_lock_irqsave(&lock->wait_lock, flags);
+	DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class);
+#endif
+	ww_ctx->acquired++;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+				  struct ww_acquire_ctx *ww_ctx)
+{
+	struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+	struct rt_mutex_waiter *waiter, *n;
+
+	/*
+	 * This branch gets optimized out for the common case,
+	 * and is only important for ww_mutex_lock.
+	 */
+	ww_mutex_lock_acquired(ww, ww_ctx);
+	ww->ctx = ww_ctx;
+
+	/*
+	 * Give any possible sleeping processes the chance to wake up,
+	 * so they can recheck if they have to back off.
+	 */
+	rbtree_postorder_for_each_entry_safe(waiter, n, &lock->waiters.rb_root,
+					     tree_entry) {
+		/* XXX debug rt mutex waiter wakeup */
+
+		BUG_ON(waiter->lock != lock);
+		rt_mutex_wake_waiter(waiter);
+	}
+}
+
+#else
+
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+				  struct ww_acquire_ctx *ww_ctx)
+{
+	BUG();
+}
+#endif
+
+int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state,
+				     struct hrtimer_sleeper *timeout,
+				     enum rtmutex_chainwalk chwalk,
+				     struct ww_acquire_ctx *ww_ctx,
+				     struct rt_mutex_waiter *waiter)
+{
+	int ret;
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (ww_ctx) {
+		struct ww_mutex *ww;
+
+		ww = container_of(lock, struct ww_mutex, base.lock);
+		if (unlikely(ww_ctx == READ_ONCE(ww->ctx)))
+			return -EALREADY;
+	}
+#endif
 
 	/* Try to acquire the lock again: */
 	if (try_to_take_rt_mutex(lock, current, NULL)) {
-		raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+		if (ww_ctx)
+			ww_mutex_account_lock(lock, ww_ctx);
 		return 0;
 	}
 
@@ -1260,16 +1733,26 @@ rt_mutex_slowlock(struct rt_mutex *lock,
 	if (unlikely(timeout))
 		hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
 
-	ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk);
+	ret = task_blocks_on_rt_mutex(lock, waiter, current, chwalk);
 
-	if (likely(!ret))
+	if (likely(!ret)) {
 		/* sleep on the mutex */
-		ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
+		ret = __rt_mutex_slowlock(lock, state, timeout, waiter,
+					  ww_ctx);
+	} else if (ww_ctx) {
+		/* ww_mutex received EDEADLK, let it become EALREADY */
+		ret = __mutex_lock_check_stamp(lock, ww_ctx);
+		BUG_ON(!ret);
+	}
 
 	if (unlikely(ret)) {
 		__set_current_state(TASK_RUNNING);
-		remove_waiter(lock, &waiter);
-		rt_mutex_handle_deadlock(ret, chwalk, &waiter);
+		remove_waiter(lock, waiter);
+		/* ww_mutex wants to report EDEADLK/EALREADY, let it */
+		if (!ww_ctx)
+			rt_mutex_handle_deadlock(ret, chwalk, waiter);
+	} else if (ww_ctx) {
+		ww_mutex_account_lock(lock, ww_ctx);
 	}
 
 	/*
@@ -1277,6 +1760,36 @@ rt_mutex_slowlock(struct rt_mutex *lock,
 	 * unconditionally. We might have to fix that up.
 	 */
 	fixup_rt_mutex_waiters(lock);
+	return ret;
+}
+
+/*
+ * Slow path lock function:
+ */
+static int __sched
+rt_mutex_slowlock(struct rt_mutex *lock, int state,
+		  struct hrtimer_sleeper *timeout,
+		  enum rtmutex_chainwalk chwalk,
+		  struct ww_acquire_ctx *ww_ctx)
+{
+	struct rt_mutex_waiter waiter;
+	unsigned long flags;
+	int ret = 0;
+
+	rt_mutex_init_waiter(&waiter, false);
+
+	/*
+	 * Technically we could use raw_spin_[un]lock_irq() here, but this can
+	 * be called in early boot if the cmpxchg() fast path is disabled
+	 * (debug, no architecture support). In this case we will acquire the
+	 * rtmutex with lock->wait_lock held. But we cannot unconditionally
+	 * enable interrupts in that early boot case. So we need to use the
+	 * irqsave/restore variants.
+	 */
+	raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+	ret = rt_mutex_slowlock_locked(lock, state, timeout, chwalk, ww_ctx,
+				       &waiter);
 
 	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 
@@ -1337,7 +1850,8 @@ static inline int rt_mutex_slowtrylock(s
  * Return whether the current task needs to call rt_mutex_postunlock().
  */
 static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
-					struct wake_q_head *wake_q)
+					struct wake_q_head *wake_q,
+					struct wake_q_head *wake_sleeper_q)
 {
 	unsigned long flags;
 
@@ -1391,7 +1905,7 @@ static bool __sched rt_mutex_slowunlock(
 	 *
 	 * Queue the next waiter for wakeup once we release the wait_lock.
 	 */
-	mark_wakeup_next_waiter(wake_q, lock);
+	mark_wakeup_next_waiter(wake_q, wake_sleeper_q, lock);
 	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 
 	return true; /* call rt_mutex_postunlock() */
@@ -1405,29 +1919,45 @@ static bool __sched rt_mutex_slowunlock(
  */
 static inline int
 rt_mutex_fastlock(struct rt_mutex *lock, int state,
+		  struct ww_acquire_ctx *ww_ctx,
 		  int (*slowfn)(struct rt_mutex *lock, int state,
 				struct hrtimer_sleeper *timeout,
-				enum rtmutex_chainwalk chwalk))
+				enum rtmutex_chainwalk chwalk,
+				struct ww_acquire_ctx *ww_ctx))
 {
 	if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
 		return 0;
 
-	return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK);
+	/*
+	 * If rt_mutex blocks, the function sched_submit_work will not call
+	 * blk_schedule_flush_plug (because tsk_is_pi_blocked would be true).
+	 * We must call blk_schedule_flush_plug here, if we don't call it,
+	 * a deadlock in I/O may happen.
+	 */
+	if (unlikely(blk_needs_flush_plug(current)))
+		blk_schedule_flush_plug(current);
+
+	return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK, ww_ctx);
 }
 
 static inline int
 rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
 			struct hrtimer_sleeper *timeout,
 			enum rtmutex_chainwalk chwalk,
+			struct ww_acquire_ctx *ww_ctx,
 			int (*slowfn)(struct rt_mutex *lock, int state,
 				      struct hrtimer_sleeper *timeout,
-				      enum rtmutex_chainwalk chwalk))
+				      enum rtmutex_chainwalk chwalk,
+				      struct ww_acquire_ctx *ww_ctx))
 {
 	if (chwalk == RT_MUTEX_MIN_CHAINWALK &&
 	    likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
 		return 0;
 
-	return slowfn(lock, state, timeout, chwalk);
+	if (unlikely(blk_needs_flush_plug(current)))
+		blk_schedule_flush_plug(current);
+
+	return slowfn(lock, state, timeout, chwalk, ww_ctx);
 }
 
 static inline int
@@ -1443,9 +1973,11 @@ rt_mutex_fasttrylock(struct rt_mutex *lo
 /*
  * Performs the wakeup of the the top-waiter and re-enables preemption.
  */
-void rt_mutex_postunlock(struct wake_q_head *wake_q)
+void rt_mutex_postunlock(struct wake_q_head *wake_q,
+			 struct wake_q_head *wake_sleeper_q)
 {
 	wake_up_q(wake_q);
+	wake_up_q_sleeper(wake_sleeper_q);
 
 	/* Pairs with preempt_disable() in rt_mutex_slowunlock() */
 	preempt_enable();
@@ -1454,23 +1986,46 @@ void rt_mutex_postunlock(struct wake_q_h
 static inline void
 rt_mutex_fastunlock(struct rt_mutex *lock,
 		    bool (*slowfn)(struct rt_mutex *lock,
-				   struct wake_q_head *wqh))
+				   struct wake_q_head *wqh,
+				   struct wake_q_head *wq_sleeper))
 {
 	DEFINE_WAKE_Q(wake_q);
+	DEFINE_WAKE_Q(wake_sleeper_q);
 
 	if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
 		return;
 
-	if (slowfn(lock, &wake_q))
-		rt_mutex_postunlock(&wake_q);
+	if (slowfn(lock, &wake_q, &wake_sleeper_q))
+		rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
 }
 
-static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass)
+int __sched __rt_mutex_lock_state(struct rt_mutex *lock, int state)
 {
 	might_sleep();
+	return rt_mutex_fastlock(lock, state, NULL, rt_mutex_slowlock);
+}
+
+/**
+ * rt_mutex_lock_state - lock a rt_mutex with a given state
+ *
+ * @lock:      The rt_mutex to be locked
+ * @state:     The state to set when blocking on the rt_mutex
+ */
+static inline int __sched rt_mutex_lock_state(struct rt_mutex *lock,
+					      unsigned int subclass, int state)
+{
+	int ret;
 
 	mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
-	rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
+	ret = __rt_mutex_lock_state(lock, state);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+
+static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass)
+{
+	rt_mutex_lock_state(lock, subclass, TASK_UNINTERRUPTIBLE);
 }
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -1511,16 +2066,7 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock);
  */
 int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
 {
-	int ret;
-
-	might_sleep();
-
-	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-	ret = rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock);
-	if (ret)
-		mutex_release(&lock->dep_map, 1, _RET_IP_);
-
-	return ret;
+	return rt_mutex_lock_state(lock, 0, TASK_INTERRUPTIBLE);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
 
@@ -1538,6 +2084,22 @@ int __sched __rt_mutex_futex_trylock(str
 }
 
 /**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock:              the rt_mutex to be locked
+ * @detect_deadlock:   deadlock detection on/off
+ *
+ * Returns:
+ *  0          on success
+ * -EINTR      when interrupted by a signal
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+	return rt_mutex_lock_state(lock, 0, TASK_KILLABLE);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
+/**
  * rt_mutex_timed_lock - lock a rt_mutex interruptible
  *			the timeout structure is provided
  *			by the caller
@@ -1560,6 +2122,7 @@ rt_mutex_timed_lock(struct rt_mutex *loc
 	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
 	ret = rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
 				       RT_MUTEX_MIN_CHAINWALK,
+				       NULL,
 				       rt_mutex_slowlock);
 	if (ret)
 		mutex_release(&lock->dep_map, 1, _RET_IP_);
@@ -1568,6 +2131,18 @@ rt_mutex_timed_lock(struct rt_mutex *loc
 }
 EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
 
+int __sched __rt_mutex_trylock(struct rt_mutex *lock)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (WARN_ON_ONCE(in_irq() || in_nmi()))
+#else
+	if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
+#endif
+		return 0;
+
+	return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
+}
+
 /**
  * rt_mutex_trylock - try to lock a rt_mutex
  *
@@ -1583,10 +2158,7 @@ int __sched rt_mutex_trylock(struct rt_m
 {
 	int ret;
 
-	if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
-		return 0;
-
-	ret = rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
+	ret = __rt_mutex_trylock(lock);
 	if (ret)
 		mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
 
@@ -1594,6 +2166,11 @@ int __sched rt_mutex_trylock(struct rt_m
 }
 EXPORT_SYMBOL_GPL(rt_mutex_trylock);
 
+void __sched __rt_mutex_unlock(struct rt_mutex *lock)
+{
+	rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
+}
+
 /**
  * rt_mutex_unlock - unlock a rt_mutex
  *
@@ -1602,16 +2179,13 @@ EXPORT_SYMBOL_GPL(rt_mutex_trylock);
 void __sched rt_mutex_unlock(struct rt_mutex *lock)
 {
 	mutex_release(&lock->dep_map, 1, _RET_IP_);
-	rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
+	__rt_mutex_unlock(lock);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_unlock);
 
-/**
- * Futex variant, that since futex variants do not use the fast-path, can be
- * simple and will not need to retry.
- */
-bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
-				    struct wake_q_head *wake_q)
+static bool __sched __rt_mutex_unlock_common(struct rt_mutex *lock,
+					     struct wake_q_head *wake_q,
+					     struct wake_q_head *wq_sleeper)
 {
 	lockdep_assert_held(&lock->wait_lock);
 
@@ -1628,23 +2202,35 @@ bool __sched __rt_mutex_futex_unlock(str
 	 * avoid inversion prior to the wakeup.  preempt_disable()
 	 * therein pairs with rt_mutex_postunlock().
 	 */
-	mark_wakeup_next_waiter(wake_q, lock);
+	mark_wakeup_next_waiter(wake_q, wq_sleeper, lock);
 
 	return true; /* call postunlock() */
 }
 
+/**
+ * Futex variant, that since futex variants do not use the fast-path, can be
+ * simple and will not need to retry.
+ */
+bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
+				     struct wake_q_head *wake_q,
+				     struct wake_q_head *wq_sleeper)
+{
+	return __rt_mutex_unlock_common(lock, wake_q, wq_sleeper);
+}
+
 void __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
 {
 	DEFINE_WAKE_Q(wake_q);
+	DEFINE_WAKE_Q(wake_sleeper_q);
 	unsigned long flags;
 	bool postunlock;
 
 	raw_spin_lock_irqsave(&lock->wait_lock, flags);
-	postunlock = __rt_mutex_futex_unlock(lock, &wake_q);
+	postunlock = __rt_mutex_futex_unlock(lock, &wake_q, &wake_sleeper_q);
 	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 
 	if (postunlock)
-		rt_mutex_postunlock(&wake_q);
+		rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
 }
 
 /**
@@ -1683,7 +2269,7 @@ void __rt_mutex_init(struct rt_mutex *lo
 	if (name && key)
 		debug_rt_mutex_init(lock, name, key);
 }
-EXPORT_SYMBOL_GPL(__rt_mutex_init);
+EXPORT_SYMBOL(__rt_mutex_init);
 
 /**
  * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
@@ -1703,6 +2289,14 @@ void rt_mutex_init_proxy_locked(struct r
 				struct task_struct *proxy_owner)
 {
 	__rt_mutex_init(lock, NULL, NULL);
+#ifdef CONFIG_DEBUG_SPINLOCK
+	/*
+	 * get another key class for the wait_lock. LOCK_PI and UNLOCK_PI is
+	 * holding the ->wait_lock of the proxy_lock while unlocking a sleeping
+	 * lock.
+	 */
+	raw_spin_lock_init(&lock->wait_lock);
+#endif
 	debug_rt_mutex_proxy_lock(lock, proxy_owner);
 	rt_mutex_set_owner(lock, proxy_owner);
 }
@@ -1756,6 +2350,34 @@ int __rt_mutex_start_proxy_lock(struct r
 	if (try_to_take_rt_mutex(lock, task, NULL))
 		return 1;
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	/*
+	 * In PREEMPT_RT there's an added race.
+	 * If the task, that we are about to requeue, times out,
+	 * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue
+	 * to skip this task. But right after the task sets
+	 * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then
+	 * block on the spin_lock(&hb->lock), which in RT is an rtmutex.
+	 * This will replace the PI_WAKEUP_INPROGRESS with the actual
+	 * lock that it blocks on. We *must not* place this task
+	 * on this proxy lock in that case.
+	 *
+	 * To prevent this race, we first take the task's pi_lock
+	 * and check if it has updated its pi_blocked_on. If it has,
+	 * we assume that it woke up and we return -EAGAIN.
+	 * Otherwise, we set the task's pi_blocked_on to
+	 * PI_REQUEUE_INPROGRESS, so that if the task is waking up
+	 * it will know that we are in the process of requeuing it.
+	 */
+	raw_spin_lock(&task->pi_lock);
+	if (task->pi_blocked_on) {
+		raw_spin_unlock(&task->pi_lock);
+		return -EAGAIN;
+	}
+	task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
+	raw_spin_unlock(&task->pi_lock);
+#endif
+
 	/* We enforce deadlock detection for futexes */
 	ret = task_blocks_on_rt_mutex(lock, waiter, task,
 				      RT_MUTEX_FULL_CHAINWALK);
@@ -1850,17 +2472,36 @@ int rt_mutex_wait_proxy_lock(struct rt_m
 			       struct hrtimer_sleeper *to,
 			       struct rt_mutex_waiter *waiter)
 {
+	struct task_struct *tsk = current;
 	int ret;
 
 	raw_spin_lock_irq(&lock->wait_lock);
 	/* sleep on the mutex */
 	set_current_state(TASK_INTERRUPTIBLE);
-	ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
+	ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL);
 	/*
 	 * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
 	 * have to fix that up.
 	 */
 	fixup_rt_mutex_waiters(lock);
+	/*
+	 * RT has a problem here when the wait got interrupted by a timeout
+	 * or a signal. task->pi_blocked_on is still set. The task must
+	 * acquire the hash bucket lock when returning from this function.
+	 *
+	 * If the hash bucket lock is contended then the
+	 * BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on)) in
+	 * task_blocks_on_rt_mutex() will trigger. This can be avoided by
+	 * clearing task->pi_blocked_on which removes the task from the
+	 * boosting chain of the rtmutex. That's correct because the task
+	 * is not longer blocked on it.
+	 */
+	if (ret) {
+		raw_spin_lock(&tsk->pi_lock);
+		tsk->pi_blocked_on = NULL;
+		raw_spin_unlock(&tsk->pi_lock);
+	}
+
 	raw_spin_unlock_irq(&lock->wait_lock);
 
 	return ret;
@@ -1922,3 +2563,99 @@ bool rt_mutex_cleanup_proxy_lock(struct
 
 	return cleanup;
 }
+
+static inline int
+ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+	unsigned tmp;
+
+	if (ctx->deadlock_inject_countdown-- == 0) {
+		tmp = ctx->deadlock_inject_interval;
+		if (tmp > UINT_MAX/4)
+			tmp = UINT_MAX;
+		else
+			tmp = tmp*2 + tmp + tmp/2;
+
+		ctx->deadlock_inject_interval = tmp;
+		ctx->deadlock_inject_countdown = tmp;
+		ctx->contending_lock = lock;
+
+		ww_mutex_unlock(lock);
+
+		return -EDEADLK;
+	}
+#endif
+
+	return 0;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+int __sched
+ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+	int ret;
+
+	might_sleep();
+
+	mutex_acquire_nest(&lock->base.dep_map, 0, 0,
+			   ctx ? &ctx->dep_map : NULL, _RET_IP_);
+	ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0,
+				ctx);
+	if (ret)
+		mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+	else if (!ret && ctx && ctx->acquired > 1)
+		return ww_mutex_deadlock_injection(lock, ctx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ww_mutex_lock_interruptible);
+
+int __sched
+ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+	int ret;
+
+	might_sleep();
+
+	mutex_acquire_nest(&lock->base.dep_map, 0, 0,
+			   ctx ? &ctx->dep_map : NULL, _RET_IP_);
+	ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0,
+				ctx);
+	if (ret)
+		mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+	else if (!ret && ctx && ctx->acquired > 1)
+		return ww_mutex_deadlock_injection(lock, ctx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ww_mutex_lock);
+
+void __sched ww_mutex_unlock(struct ww_mutex *lock)
+{
+	int nest = !!lock->ctx;
+
+	/*
+	 * The unlocking fastpath is the 0->1 transition from 'locked'
+	 * into 'unlocked' state:
+	 */
+	if (nest) {
+#ifdef CONFIG_DEBUG_MUTEXES
+		DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired);
+#endif
+		if (lock->ctx->acquired > 0)
+			lock->ctx->acquired--;
+		lock->ctx = NULL;
+	}
+
+	mutex_release(&lock->base.dep_map, nest, _RET_IP_);
+	__rt_mutex_unlock(&lock->base.lock);
+}
+EXPORT_SYMBOL(ww_mutex_unlock);
+
+int __rt_mutex_owner_current(struct rt_mutex *lock)
+{
+	return rt_mutex_owner(lock) == current;
+}
+EXPORT_SYMBOL(__rt_mutex_owner_current);
+#endif
Index: linux-4.19.25-rt16/kernel/locking/rtmutex_common.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/locking/rtmutex_common.h
+++ linux-4.19.25-rt16/kernel/locking/rtmutex_common.h
@@ -15,6 +15,7 @@
 
 #include <linux/rtmutex.h>
 #include <linux/sched/wake_q.h>
+#include <linux/sched/debug.h>
 
 /*
  * This is the control structure for tasks blocked on a rt_mutex,
@@ -29,6 +30,7 @@ struct rt_mutex_waiter {
 	struct rb_node          pi_tree_entry;
 	struct task_struct	*task;
 	struct rt_mutex		*lock;
+	bool			savestate;
 #ifdef CONFIG_DEBUG_RT_MUTEXES
 	unsigned long		ip;
 	struct pid		*deadlock_task_pid;
@@ -130,12 +132,15 @@ enum rtmutex_chainwalk {
 /*
  * PI-futex support (proxy locking functions, etc.):
  */
+#define PI_WAKEUP_INPROGRESS	((struct rt_mutex_waiter *) 1)
+#define PI_REQUEUE_INPROGRESS	((struct rt_mutex_waiter *) 2)
+
 extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
 extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
 				       struct task_struct *proxy_owner);
 extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
 				  struct task_struct *proxy_owner);
-extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
+extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savetate);
 extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
 				     struct rt_mutex_waiter *waiter,
 				     struct task_struct *task);
@@ -153,9 +158,27 @@ extern int __rt_mutex_futex_trylock(stru
 
 extern void rt_mutex_futex_unlock(struct rt_mutex *lock);
 extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock,
-				 struct wake_q_head *wqh);
+				 struct wake_q_head *wqh,
+				 struct wake_q_head *wq_sleeper);
+
+extern void rt_mutex_postunlock(struct wake_q_head *wake_q,
+				struct wake_q_head *wake_sleeper_q);
+
+/* RW semaphore special interface */
+struct ww_acquire_ctx;
 
-extern void rt_mutex_postunlock(struct wake_q_head *wake_q);
+extern int __rt_mutex_lock_state(struct rt_mutex *lock, int state);
+extern int __rt_mutex_trylock(struct rt_mutex *lock);
+extern void __rt_mutex_unlock(struct rt_mutex *lock);
+int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state,
+				     struct hrtimer_sleeper *timeout,
+				     enum rtmutex_chainwalk chwalk,
+				     struct ww_acquire_ctx *ww_ctx,
+				     struct rt_mutex_waiter *waiter);
+void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock,
+					  struct rt_mutex_waiter *waiter,
+					  unsigned long flags);
+void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock);
 
 #ifdef CONFIG_DEBUG_RT_MUTEXES
 # include "rtmutex-debug.h"
Index: linux-4.19.25-rt16/kernel/locking/rwlock-rt.c
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/kernel/locking/rwlock-rt.c
@@ -0,0 +1,378 @@
+/*
+ */
+#include <linux/sched/debug.h>
+#include <linux/export.h>
+
+#include "rtmutex_common.h"
+#include <linux/rwlock_types_rt.h>
+
+/*
+ * RT-specific reader/writer locks
+ *
+ * write_lock()
+ *  1) Lock lock->rtmutex
+ *  2) Remove the reader BIAS to force readers into the slow path
+ *  3) Wait until all readers have left the critical region
+ *  4) Mark it write locked
+ *
+ * write_unlock()
+ *  1) Remove the write locked marker
+ *  2) Set the reader BIAS so readers can use the fast path again
+ *  3) Unlock lock->rtmutex to release blocked readers
+ *
+ * read_lock()
+ *  1) Try fast path acquisition (reader BIAS is set)
+ *  2) Take lock->rtmutex.wait_lock which protects the writelocked flag
+ *  3) If !writelocked, acquire it for read
+ *  4) If writelocked, block on lock->rtmutex
+ *  5) unlock lock->rtmutex, goto 1)
+ *
+ * read_unlock()
+ *  1) Try fast path release (reader count != 1)
+ *  2) Wake the writer waiting in write_lock()#3
+ *
+ * read_lock()#3 has the consequence, that rw locks on RT are not writer
+ * fair, but writers, which should be avoided in RT tasks (think tasklist
+ * lock), are subject to the rtmutex priority/DL inheritance mechanism.
+ *
+ * It's possible to make the rw locks writer fair by keeping a list of
+ * active readers. A blocked writer would force all newly incoming readers
+ * to block on the rtmutex, but the rtmutex would have to be proxy locked
+ * for one reader after the other. We can't use multi-reader inheritance
+ * because there is no way to support that with
+ * SCHED_DEADLINE. Implementing the one by one reader boosting/handover
+ * mechanism is a major surgery for a very dubious value.
+ *
+ * The risk of writer starvation is there, but the pathological use cases
+ * which trigger it are not necessarily the typical RT workloads.
+ */
+
+void __rwlock_biased_rt_init(struct rt_rw_lock *lock, const char *name,
+			     struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held semaphore:
+	 */
+	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+	lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
+	atomic_set(&lock->readers, READER_BIAS);
+	rt_mutex_init(&lock->rtmutex);
+	lock->rtmutex.save_state = 1;
+}
+
+int __read_rt_trylock(struct rt_rw_lock *lock)
+{
+	int r, old;
+
+	/*
+	 * Increment reader count, if lock->readers < 0, i.e. READER_BIAS is
+	 * set.
+	 */
+	for (r = atomic_read(&lock->readers); r < 0;) {
+		old = atomic_cmpxchg(&lock->readers, r, r + 1);
+		if (likely(old == r))
+			return 1;
+		r = old;
+	}
+	return 0;
+}
+
+void __sched __read_rt_lock(struct rt_rw_lock *lock)
+{
+	struct rt_mutex *m = &lock->rtmutex;
+	struct rt_mutex_waiter waiter;
+	unsigned long flags;
+
+	if (__read_rt_trylock(lock))
+		return;
+
+	raw_spin_lock_irqsave(&m->wait_lock, flags);
+	/*
+	 * Allow readers as long as the writer has not completely
+	 * acquired the semaphore for write.
+	 */
+	if (atomic_read(&lock->readers) != WRITER_BIAS) {
+		atomic_inc(&lock->readers);
+		raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+		return;
+	}
+
+	/*
+	 * Call into the slow lock path with the rtmutex->wait_lock
+	 * held, so this can't result in the following race:
+	 *
+	 * Reader1		Reader2		Writer
+	 *			read_lock()
+	 *					write_lock()
+	 *					rtmutex_lock(m)
+	 *					swait()
+	 * read_lock()
+	 * unlock(m->wait_lock)
+	 *			read_unlock()
+	 *			swake()
+	 *					lock(m->wait_lock)
+	 *					lock->writelocked=true
+	 *					unlock(m->wait_lock)
+	 *
+	 *					write_unlock()
+	 *					lock->writelocked=false
+	 *					rtmutex_unlock(m)
+	 *			read_lock()
+	 *					write_lock()
+	 *					rtmutex_lock(m)
+	 *					swait()
+	 * rtmutex_lock(m)
+	 *
+	 * That would put Reader1 behind the writer waiting on
+	 * Reader2 to call read_unlock() which might be unbound.
+	 */
+	rt_mutex_init_waiter(&waiter, true);
+	rt_spin_lock_slowlock_locked(m, &waiter, flags);
+	/*
+	 * The slowlock() above is guaranteed to return with the rtmutex is
+	 * now held, so there can't be a writer active. Increment the reader
+	 * count and immediately drop the rtmutex again.
+	 */
+	atomic_inc(&lock->readers);
+	raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+	rt_spin_lock_slowunlock(m);
+
+	debug_rt_mutex_free_waiter(&waiter);
+}
+
+void __read_rt_unlock(struct rt_rw_lock *lock)
+{
+	struct rt_mutex *m = &lock->rtmutex;
+	struct task_struct *tsk;
+
+	/*
+	 * sem->readers can only hit 0 when a writer is waiting for the
+	 * active readers to leave the critical region.
+	 */
+	if (!atomic_dec_and_test(&lock->readers))
+		return;
+
+	raw_spin_lock_irq(&m->wait_lock);
+	/*
+	 * Wake the writer, i.e. the rtmutex owner. It might release the
+	 * rtmutex concurrently in the fast path, but to clean up the rw
+	 * lock it needs to acquire m->wait_lock. The worst case which can
+	 * happen is a spurious wakeup.
+	 */
+	tsk = rt_mutex_owner(m);
+	if (tsk)
+		wake_up_process(tsk);
+
+	raw_spin_unlock_irq(&m->wait_lock);
+}
+
+static void __write_unlock_common(struct rt_rw_lock *lock, int bias,
+				  unsigned long flags)
+{
+	struct rt_mutex *m = &lock->rtmutex;
+
+	atomic_add(READER_BIAS - bias, &lock->readers);
+	raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+	rt_spin_lock_slowunlock(m);
+}
+
+void __sched __write_rt_lock(struct rt_rw_lock *lock)
+{
+	struct rt_mutex *m = &lock->rtmutex;
+	struct task_struct *self = current;
+	unsigned long flags;
+
+	/* Take the rtmutex as a first step */
+	__rt_spin_lock(m);
+
+	/* Force readers into slow path */
+	atomic_sub(READER_BIAS, &lock->readers);
+
+	raw_spin_lock_irqsave(&m->wait_lock, flags);
+
+	raw_spin_lock(&self->pi_lock);
+	self->saved_state = self->state;
+	__set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+	raw_spin_unlock(&self->pi_lock);
+
+	for (;;) {
+		/* Have all readers left the critical region? */
+		if (!atomic_read(&lock->readers)) {
+			atomic_set(&lock->readers, WRITER_BIAS);
+			raw_spin_lock(&self->pi_lock);
+			__set_current_state_no_track(self->saved_state);
+			self->saved_state = TASK_RUNNING;
+			raw_spin_unlock(&self->pi_lock);
+			raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+			return;
+		}
+
+		raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+
+		if (atomic_read(&lock->readers) != 0)
+			schedule();
+
+		raw_spin_lock_irqsave(&m->wait_lock, flags);
+
+		raw_spin_lock(&self->pi_lock);
+		__set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+		raw_spin_unlock(&self->pi_lock);
+	}
+}
+
+int __write_rt_trylock(struct rt_rw_lock *lock)
+{
+	struct rt_mutex *m = &lock->rtmutex;
+	unsigned long flags;
+
+	if (!__rt_mutex_trylock(m))
+		return 0;
+
+	atomic_sub(READER_BIAS, &lock->readers);
+
+	raw_spin_lock_irqsave(&m->wait_lock, flags);
+	if (!atomic_read(&lock->readers)) {
+		atomic_set(&lock->readers, WRITER_BIAS);
+		raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+		return 1;
+	}
+	__write_unlock_common(lock, 0, flags);
+	return 0;
+}
+
+void __write_rt_unlock(struct rt_rw_lock *lock)
+{
+	struct rt_mutex *m = &lock->rtmutex;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&m->wait_lock, flags);
+	__write_unlock_common(lock, WRITER_BIAS, flags);
+}
+
+/* Map the reader biased implementation */
+static inline int do_read_rt_trylock(rwlock_t *rwlock)
+{
+	return __read_rt_trylock(rwlock);
+}
+
+static inline int do_write_rt_trylock(rwlock_t *rwlock)
+{
+	return __write_rt_trylock(rwlock);
+}
+
+static inline void do_read_rt_lock(rwlock_t *rwlock)
+{
+	__read_rt_lock(rwlock);
+}
+
+static inline void do_write_rt_lock(rwlock_t *rwlock)
+{
+	__write_rt_lock(rwlock);
+}
+
+static inline void do_read_rt_unlock(rwlock_t *rwlock)
+{
+	__read_rt_unlock(rwlock);
+}
+
+static inline void do_write_rt_unlock(rwlock_t *rwlock)
+{
+	__write_rt_unlock(rwlock);
+}
+
+static inline void do_rwlock_rt_init(rwlock_t *rwlock, const char *name,
+				     struct lock_class_key *key)
+{
+	__rwlock_biased_rt_init(rwlock, name, key);
+}
+
+int __lockfunc rt_read_can_lock(rwlock_t *rwlock)
+{
+	return  atomic_read(&rwlock->readers) < 0;
+}
+
+int __lockfunc rt_write_can_lock(rwlock_t *rwlock)
+{
+	return atomic_read(&rwlock->readers) == READER_BIAS;
+}
+
+/*
+ * The common functions which get wrapped into the rwlock API.
+ */
+int __lockfunc rt_read_trylock(rwlock_t *rwlock)
+{
+	int ret;
+
+	sleeping_lock_inc();
+	migrate_disable();
+	ret = do_read_rt_trylock(rwlock);
+	if (ret) {
+		rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_);
+	} else {
+		migrate_enable();
+		sleeping_lock_dec();
+	}
+	return ret;
+}
+EXPORT_SYMBOL(rt_read_trylock);
+
+int __lockfunc rt_write_trylock(rwlock_t *rwlock)
+{
+	int ret;
+
+	sleeping_lock_inc();
+	migrate_disable();
+	ret = do_write_rt_trylock(rwlock);
+	if (ret) {
+		rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+	} else {
+		migrate_enable();
+		sleeping_lock_dec();
+	}
+	return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock);
+
+void __lockfunc rt_read_lock(rwlock_t *rwlock)
+{
+	sleeping_lock_inc();
+	migrate_disable();
+	rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_);
+	do_read_rt_lock(rwlock);
+}
+EXPORT_SYMBOL(rt_read_lock);
+
+void __lockfunc rt_write_lock(rwlock_t *rwlock)
+{
+	sleeping_lock_inc();
+	migrate_disable();
+	rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+	do_write_rt_lock(rwlock);
+}
+EXPORT_SYMBOL(rt_write_lock);
+
+void __lockfunc rt_read_unlock(rwlock_t *rwlock)
+{
+	rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+	do_read_rt_unlock(rwlock);
+	migrate_enable();
+	sleeping_lock_dec();
+}
+EXPORT_SYMBOL(rt_read_unlock);
+
+void __lockfunc rt_write_unlock(rwlock_t *rwlock)
+{
+	rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+	do_write_rt_unlock(rwlock);
+	migrate_enable();
+	sleeping_lock_dec();
+}
+EXPORT_SYMBOL(rt_write_unlock);
+
+void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key)
+{
+	do_rwlock_rt_init(rwlock, name, key);
+}
+EXPORT_SYMBOL(__rt_rwlock_init);
Index: linux-4.19.25-rt16/kernel/locking/rwsem-rt.c
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/kernel/locking/rwsem-rt.c
@@ -0,0 +1,302 @@
+/*
+ */
+#include <linux/blkdev.h>
+#include <linux/rwsem.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/signal.h>
+#include <linux/export.h>
+
+#include "rtmutex_common.h"
+
+/*
+ * RT-specific reader/writer semaphores
+ *
+ * down_write()
+ *  1) Lock sem->rtmutex
+ *  2) Remove the reader BIAS to force readers into the slow path
+ *  3) Wait until all readers have left the critical region
+ *  4) Mark it write locked
+ *
+ * up_write()
+ *  1) Remove the write locked marker
+ *  2) Set the reader BIAS so readers can use the fast path again
+ *  3) Unlock sem->rtmutex to release blocked readers
+ *
+ * down_read()
+ *  1) Try fast path acquisition (reader BIAS is set)
+ *  2) Take sem->rtmutex.wait_lock which protects the writelocked flag
+ *  3) If !writelocked, acquire it for read
+ *  4) If writelocked, block on sem->rtmutex
+ *  5) unlock sem->rtmutex, goto 1)
+ *
+ * up_read()
+ *  1) Try fast path release (reader count != 1)
+ *  2) Wake the writer waiting in down_write()#3
+ *
+ * down_read()#3 has the consequence, that rw semaphores on RT are not writer
+ * fair, but writers, which should be avoided in RT tasks (think mmap_sem),
+ * are subject to the rtmutex priority/DL inheritance mechanism.
+ *
+ * It's possible to make the rw semaphores writer fair by keeping a list of
+ * active readers. A blocked writer would force all newly incoming readers to
+ * block on the rtmutex, but the rtmutex would have to be proxy locked for one
+ * reader after the other. We can't use multi-reader inheritance because there
+ * is no way to support that with SCHED_DEADLINE. Implementing the one by one
+ * reader boosting/handover mechanism is a major surgery for a very dubious
+ * value.
+ *
+ * The risk of writer starvation is there, but the pathological use cases
+ * which trigger it are not necessarily the typical RT workloads.
+ */
+
+void __rwsem_init(struct rw_semaphore *sem, const char *name,
+		  struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held semaphore:
+	 */
+	debug_check_no_locks_freed((void *)sem, sizeof(*sem));
+	lockdep_init_map(&sem->dep_map, name, key, 0);
+#endif
+	atomic_set(&sem->readers, READER_BIAS);
+}
+EXPORT_SYMBOL(__rwsem_init);
+
+int __down_read_trylock(struct rw_semaphore *sem)
+{
+	int r, old;
+
+	/*
+	 * Increment reader count, if sem->readers < 0, i.e. READER_BIAS is
+	 * set.
+	 */
+	for (r = atomic_read(&sem->readers); r < 0;) {
+		old = atomic_cmpxchg(&sem->readers, r, r + 1);
+		if (likely(old == r))
+			return 1;
+		r = old;
+	}
+	return 0;
+}
+
+static int __sched __down_read_common(struct rw_semaphore *sem, int state)
+{
+	struct rt_mutex *m = &sem->rtmutex;
+	struct rt_mutex_waiter waiter;
+	int ret;
+
+	if (__down_read_trylock(sem))
+		return 0;
+	/*
+	 * If rt_mutex blocks, the function sched_submit_work will not call
+	 * blk_schedule_flush_plug (because tsk_is_pi_blocked would be true).
+	 * We must call blk_schedule_flush_plug here, if we don't call it,
+	 * a deadlock in I/O may happen.
+	 */
+	if (unlikely(blk_needs_flush_plug(current)))
+		blk_schedule_flush_plug(current);
+
+	might_sleep();
+	raw_spin_lock_irq(&m->wait_lock);
+	/*
+	 * Allow readers as long as the writer has not completely
+	 * acquired the semaphore for write.
+	 */
+	if (atomic_read(&sem->readers) != WRITER_BIAS) {
+		atomic_inc(&sem->readers);
+		raw_spin_unlock_irq(&m->wait_lock);
+		return 0;
+	}
+
+	/*
+	 * Call into the slow lock path with the rtmutex->wait_lock
+	 * held, so this can't result in the following race:
+	 *
+	 * Reader1		Reader2		Writer
+	 *			down_read()
+	 *					down_write()
+	 *					rtmutex_lock(m)
+	 *					swait()
+	 * down_read()
+	 * unlock(m->wait_lock)
+	 *			up_read()
+	 *			swake()
+	 *					lock(m->wait_lock)
+	 *					sem->writelocked=true
+	 *					unlock(m->wait_lock)
+	 *
+	 *					up_write()
+	 *					sem->writelocked=false
+	 *					rtmutex_unlock(m)
+	 *			down_read()
+	 *					down_write()
+	 *					rtmutex_lock(m)
+	 *					swait()
+	 * rtmutex_lock(m)
+	 *
+	 * That would put Reader1 behind the writer waiting on
+	 * Reader2 to call up_read() which might be unbound.
+	 */
+	rt_mutex_init_waiter(&waiter, false);
+	ret = rt_mutex_slowlock_locked(m, state, NULL, RT_MUTEX_MIN_CHAINWALK,
+				       NULL, &waiter);
+	/*
+	 * The slowlock() above is guaranteed to return with the rtmutex (for
+	 * ret = 0) is now held, so there can't be a writer active. Increment
+	 * the reader count and immediately drop the rtmutex again.
+	 * For ret != 0 we don't hold the rtmutex and need unlock the wait_lock.
+	 * We don't own the lock then.
+	 */
+	if (!ret)
+		atomic_inc(&sem->readers);
+	raw_spin_unlock_irq(&m->wait_lock);
+	if (!ret)
+		__rt_mutex_unlock(m);
+
+	debug_rt_mutex_free_waiter(&waiter);
+	return ret;
+}
+
+void __down_read(struct rw_semaphore *sem)
+{
+	int ret;
+
+	ret = __down_read_common(sem, TASK_UNINTERRUPTIBLE);
+	WARN_ON_ONCE(ret);
+}
+
+int __down_read_killable(struct rw_semaphore *sem)
+{
+	int ret;
+
+	ret = __down_read_common(sem, TASK_KILLABLE);
+	if (likely(!ret))
+		return ret;
+	WARN_ONCE(ret != -EINTR, "Unexpected state: %d\n", ret);
+	return -EINTR;
+}
+
+void __up_read(struct rw_semaphore *sem)
+{
+	struct rt_mutex *m = &sem->rtmutex;
+	struct task_struct *tsk;
+
+	/*
+	 * sem->readers can only hit 0 when a writer is waiting for the
+	 * active readers to leave the critical region.
+	 */
+	if (!atomic_dec_and_test(&sem->readers))
+		return;
+
+	might_sleep();
+	raw_spin_lock_irq(&m->wait_lock);
+	/*
+	 * Wake the writer, i.e. the rtmutex owner. It might release the
+	 * rtmutex concurrently in the fast path (due to a signal), but to
+	 * clean up the rwsem it needs to acquire m->wait_lock. The worst
+	 * case which can happen is a spurious wakeup.
+	 */
+	tsk = rt_mutex_owner(m);
+	if (tsk)
+		wake_up_process(tsk);
+
+	raw_spin_unlock_irq(&m->wait_lock);
+}
+
+static void __up_write_unlock(struct rw_semaphore *sem, int bias,
+			      unsigned long flags)
+{
+	struct rt_mutex *m = &sem->rtmutex;
+
+	atomic_add(READER_BIAS - bias, &sem->readers);
+	raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+	__rt_mutex_unlock(m);
+}
+
+static int __sched __down_write_common(struct rw_semaphore *sem, int state)
+{
+	struct rt_mutex *m = &sem->rtmutex;
+	unsigned long flags;
+
+	/* Take the rtmutex as a first step */
+	if (__rt_mutex_lock_state(m, state))
+		return -EINTR;
+
+	/* Force readers into slow path */
+	atomic_sub(READER_BIAS, &sem->readers);
+	might_sleep();
+
+	set_current_state(state);
+	for (;;) {
+		raw_spin_lock_irqsave(&m->wait_lock, flags);
+		/* Have all readers left the critical region? */
+		if (!atomic_read(&sem->readers)) {
+			atomic_set(&sem->readers, WRITER_BIAS);
+			__set_current_state(TASK_RUNNING);
+			raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+			return 0;
+		}
+
+		if (signal_pending_state(state, current)) {
+			__set_current_state(TASK_RUNNING);
+			__up_write_unlock(sem, 0, flags);
+			return -EINTR;
+		}
+		raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+
+		if (atomic_read(&sem->readers) != 0) {
+			schedule();
+			set_current_state(state);
+		}
+	}
+}
+
+void __sched __down_write(struct rw_semaphore *sem)
+{
+	__down_write_common(sem, TASK_UNINTERRUPTIBLE);
+}
+
+int __sched __down_write_killable(struct rw_semaphore *sem)
+{
+	return __down_write_common(sem, TASK_KILLABLE);
+}
+
+int __down_write_trylock(struct rw_semaphore *sem)
+{
+	struct rt_mutex *m = &sem->rtmutex;
+	unsigned long flags;
+
+	if (!__rt_mutex_trylock(m))
+		return 0;
+
+	atomic_sub(READER_BIAS, &sem->readers);
+
+	raw_spin_lock_irqsave(&m->wait_lock, flags);
+	if (!atomic_read(&sem->readers)) {
+		atomic_set(&sem->readers, WRITER_BIAS);
+		raw_spin_unlock_irqrestore(&m->wait_lock, flags);
+		return 1;
+	}
+	__up_write_unlock(sem, 0, flags);
+	return 0;
+}
+
+void __up_write(struct rw_semaphore *sem)
+{
+	struct rt_mutex *m = &sem->rtmutex;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&m->wait_lock, flags);
+	__up_write_unlock(sem, WRITER_BIAS, flags);
+}
+
+void __downgrade_write(struct rw_semaphore *sem)
+{
+	struct rt_mutex *m = &sem->rtmutex;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&m->wait_lock, flags);
+	/* Release it and account current as reader */
+	__up_write_unlock(sem, WRITER_BIAS - 1, flags);
+}
Index: linux-4.19.25-rt16/kernel/locking/spinlock.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/locking/spinlock.c
+++ linux-4.19.25-rt16/kernel/locking/spinlock.c
@@ -117,8 +117,11 @@ void __lockfunc __raw_##op##_lock_bh(loc
  *         __[spin|read|write]_lock_bh()
  */
 BUILD_LOCK_OPS(spin, raw_spinlock);
+
+#ifndef CONFIG_PREEMPT_RT_FULL
 BUILD_LOCK_OPS(read, rwlock);
 BUILD_LOCK_OPS(write, rwlock);
+#endif
 
 #endif
 
@@ -202,6 +205,8 @@ void __lockfunc _raw_spin_unlock_bh(raw_
 EXPORT_SYMBOL(_raw_spin_unlock_bh);
 #endif
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 #ifndef CONFIG_INLINE_READ_TRYLOCK
 int __lockfunc _raw_read_trylock(rwlock_t *lock)
 {
@@ -346,6 +351,8 @@ void __lockfunc _raw_write_unlock_bh(rwl
 EXPORT_SYMBOL(_raw_write_unlock_bh);
 #endif
 
+#endif /* !PREEMPT_RT_FULL */
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 
 void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
Index: linux-4.19.25-rt16/kernel/locking/spinlock_debug.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/locking/spinlock_debug.c
+++ linux-4.19.25-rt16/kernel/locking/spinlock_debug.c
@@ -31,6 +31,7 @@ void __raw_spin_lock_init(raw_spinlock_t
 
 EXPORT_SYMBOL(__raw_spin_lock_init);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void __rwlock_init(rwlock_t *lock, const char *name,
 		   struct lock_class_key *key)
 {
@@ -48,6 +49,7 @@ void __rwlock_init(rwlock_t *lock, const
 }
 
 EXPORT_SYMBOL(__rwlock_init);
+#endif
 
 static void spin_dump(raw_spinlock_t *lock, const char *msg)
 {
@@ -135,6 +137,7 @@ void do_raw_spin_unlock(raw_spinlock_t *
 	arch_spin_unlock(&lock->raw_lock);
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 static void rwlock_bug(rwlock_t *lock, const char *msg)
 {
 	if (!debug_locks_off())
@@ -224,3 +227,5 @@ void do_raw_write_unlock(rwlock_t *lock)
 	debug_write_unlock(lock);
 	arch_write_unlock(&lock->raw_lock);
 }
+
+#endif
Index: linux-4.19.25-rt16/kernel/panic.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/panic.c
+++ linux-4.19.25-rt16/kernel/panic.c
@@ -479,9 +479,11 @@ static u64 oops_id;
 
 static int init_oops_id(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	if (!oops_id)
 		get_random_bytes(&oops_id, sizeof(oops_id));
 	else
+#endif
 		oops_id++;
 
 	return 0;
Index: linux-4.19.25-rt16/kernel/power/hibernate.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/power/hibernate.c
+++ linux-4.19.25-rt16/kernel/power/hibernate.c
@@ -681,6 +681,10 @@ static int load_image_and_restore(void)
 	return error;
 }
 
+#ifndef CONFIG_SUSPEND
+bool pm_in_action;
+#endif
+
 /**
  * hibernate - Carry out system hibernation, including saving the image.
  */
@@ -694,6 +698,8 @@ int hibernate(void)
 		return -EPERM;
 	}
 
+	pm_in_action = true;
+
 	lock_system_sleep();
 	/* The snapshot device should not be opened while we're running */
 	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
@@ -772,6 +778,7 @@ int hibernate(void)
 	atomic_inc(&snapshot_device_available);
  Unlock:
 	unlock_system_sleep();
+	pm_in_action = false;
 	pr_info("hibernation exit\n");
 
 	return error;
Index: linux-4.19.25-rt16/kernel/power/suspend.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/power/suspend.c
+++ linux-4.19.25-rt16/kernel/power/suspend.c
@@ -600,6 +600,8 @@ static int enter_state(suspend_state_t s
 	return error;
 }
 
+bool pm_in_action;
+
 /**
  * pm_suspend - Externally visible function for suspending the system.
  * @state: System sleep state to enter.
@@ -614,6 +616,7 @@ int pm_suspend(suspend_state_t state)
 	if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
 		return -EINVAL;
 
+	pm_in_action = true;
 	pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
 	error = enter_state(state);
 	if (error) {
@@ -623,6 +626,7 @@ int pm_suspend(suspend_state_t state)
 		suspend_stats.success++;
 	}
 	pr_info("suspend exit\n");
+	pm_in_action = false;
 	return error;
 }
 EXPORT_SYMBOL(pm_suspend);
Index: linux-4.19.25-rt16/kernel/printk/printk.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/printk/printk.c
+++ linux-4.19.25-rt16/kernel/printk/printk.c
@@ -405,6 +405,65 @@ DEFINE_RAW_SPINLOCK(logbuf_lock);
 		printk_safe_exit_irqrestore(flags);	\
 	} while (0)
 
+#ifdef CONFIG_EARLY_PRINTK
+struct console *early_console;
+
+static void early_vprintk(const char *fmt, va_list ap)
+{
+	if (early_console) {
+		char buf[512];
+		int n = vscnprintf(buf, sizeof(buf), fmt, ap);
+
+		early_console->write(early_console, buf, n);
+	}
+}
+
+asmlinkage void early_printk(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	early_vprintk(fmt, ap);
+	va_end(ap);
+}
+
+/*
+ * This is independent of any log levels - a global
+ * kill switch that turns off all of printk.
+ *
+ * Used by the NMI watchdog if early-printk is enabled.
+ */
+static bool __read_mostly printk_killswitch;
+
+static int __init force_early_printk_setup(char *str)
+{
+	printk_killswitch = true;
+	return 0;
+}
+early_param("force_early_printk", force_early_printk_setup);
+
+void printk_kill(void)
+{
+	printk_killswitch = true;
+}
+
+#ifdef CONFIG_PRINTK
+static int forced_early_printk(const char *fmt, va_list ap)
+{
+	if (!printk_killswitch)
+		return 0;
+	early_vprintk(fmt, ap);
+	return 1;
+}
+#endif
+
+#else
+static inline int forced_early_printk(const char *fmt, va_list ap)
+{
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_PRINTK
 DECLARE_WAIT_QUEUE_HEAD(log_wait);
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
@@ -1361,12 +1420,23 @@ static int syslog_print_all(char __user
 	u64 next_seq;
 	u64 seq;
 	u32 idx;
+	int attempts = 0;
+	int num_msg;
 
 	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
 	if (!text)
 		return -ENOMEM;
 
 	logbuf_lock_irq();
+
+try_again:
+	attempts++;
+	if (attempts > 10) {
+		len = -EBUSY;
+		goto out;
+	}
+	num_msg = 0;
+
 	/*
 	 * Find first record that fits, including all following records,
 	 * into the user-provided buffer for this dump.
@@ -1379,6 +1449,14 @@ static int syslog_print_all(char __user
 		len += msg_print_text(msg, true, NULL, 0);
 		idx = log_next(idx);
 		seq++;
+		num_msg++;
+		if (num_msg > 5) {
+			num_msg = 0;
+			logbuf_unlock_irq();
+			logbuf_lock_irq();
+			if (clear_seq < log_first_seq)
+				goto try_again;
+		}
 	}
 
 	/* move first record forward until length fits into the buffer */
@@ -1390,6 +1468,14 @@ static int syslog_print_all(char __user
 		len -= msg_print_text(msg, true, NULL, 0);
 		idx = log_next(idx);
 		seq++;
+		num_msg++;
+		if (num_msg > 5) {
+			num_msg = 0;
+			logbuf_unlock_irq();
+			logbuf_lock_irq();
+			if (clear_seq < log_first_seq)
+				goto try_again;
+		}
 	}
 
 	/* last message fitting into this dump */
@@ -1427,6 +1513,7 @@ static int syslog_print_all(char __user
 		clear_seq = log_next_seq;
 		clear_idx = log_next_idx;
 	}
+out:
 	logbuf_unlock_irq();
 
 	kfree(text);
@@ -1558,6 +1645,7 @@ SYSCALL_DEFINE3(syslog, int, type, char
 	return do_syslog(type, buf, len, SYSLOG_FROM_READER);
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Special console_lock variants that help to reduce the risk of soft-lockups.
  * They allow to pass console_lock to another printk() call using a busy wait.
@@ -1698,6 +1786,15 @@ static int console_trylock_spinning(void
 	return 1;
 }
 
+#else
+
+static int console_trylock_spinning(void)
+{
+	return console_trylock();
+}
+
+#endif
+
 /*
  * Call the console drivers, asking them to write out
  * log_buf[start] to log_buf[end - 1].
@@ -1713,6 +1810,12 @@ static void call_console_drivers(const c
 	if (!console_drivers)
 		return;
 
+	if (IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) {
+		if (in_irq() || in_nmi())
+			return;
+	}
+
+	migrate_disable();
 	for_each_console(con) {
 		if (exclusive_console && con != exclusive_console)
 			continue;
@@ -1728,6 +1831,7 @@ static void call_console_drivers(const c
 		else
 			con->write(con, text, len);
 	}
+	migrate_enable();
 }
 
 int printk_delay_msec __read_mostly;
@@ -1897,6 +2001,13 @@ asmlinkage int vprintk_emit(int facility
 	bool in_sched = false;
 	unsigned long flags;
 
+	/*
+	 * Fall back to early_printk if a debugging subsystem has
+	 * killed printk output
+	 */
+	if (unlikely(forced_early_printk(fmt, args)))
+		return 1;
+
 	if (level == LOGLEVEL_SCHED) {
 		level = LOGLEVEL_DEFAULT;
 		in_sched = true;
@@ -1912,20 +2023,30 @@ asmlinkage int vprintk_emit(int facility
 
 	/* If called from the scheduler, we can not call up(). */
 	if (!in_sched) {
+		int may_trylock = 1;
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+		/*
+		 * we can't take a sleeping lock with IRQs or preeption disabled
+		 * so we can't print in these contexts
+		 */
+		if (!(preempt_count() == 0 && !irqs_disabled()))
+			may_trylock = 0;
+#endif
 		/*
 		 * Disable preemption to avoid being preempted while holding
 		 * console_sem which would prevent anyone from printing to
 		 * console
 		 */
-		preempt_disable();
+		migrate_disable();
 		/*
 		 * Try to acquire and then immediately release the console
 		 * semaphore.  The release will print out buffers and wake up
 		 * /dev/kmsg and syslog() users.
 		 */
-		if (console_trylock_spinning())
+		if (may_trylock && console_trylock_spinning())
 			console_unlock();
-		preempt_enable();
+		migrate_enable();
 	}
 
 	wake_up_klogd();
@@ -2037,26 +2158,6 @@ static bool suppress_message_printing(in
 
 #endif /* CONFIG_PRINTK */
 
-#ifdef CONFIG_EARLY_PRINTK
-struct console *early_console;
-
-asmlinkage __visible void early_printk(const char *fmt, ...)
-{
-	va_list ap;
-	char buf[512];
-	int n;
-
-	if (!early_console)
-		return;
-
-	va_start(ap, fmt);
-	n = vscnprintf(buf, sizeof(buf), fmt, ap);
-	va_end(ap);
-
-	early_console->write(early_console, buf, n);
-}
-#endif
-
 static int __add_preferred_console(char *name, int idx, char *options,
 				   char *brl_options)
 {
@@ -2398,6 +2499,10 @@ skip:
 		console_seq++;
 		raw_spin_unlock(&logbuf_lock);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+		printk_safe_exit_irqrestore(flags);
+		call_console_drivers(ext_text, ext_len, text, len);
+#else
 		/*
 		 * While actively printing out messages, if another printk()
 		 * were to occur on another CPU, it may wait for this one to
@@ -2416,6 +2521,7 @@ skip:
 		}
 
 		printk_safe_exit_irqrestore(flags);
+#endif
 
 		if (do_cond_resched)
 			cond_resched();
@@ -2467,6 +2573,11 @@ void console_unblank(void)
 {
 	struct console *c;
 
+	if (IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) {
+		if (in_irq() || in_nmi())
+			return;
+	}
+
 	/*
 	 * console_unblank can no longer be called in interrupt context unless
 	 * oops_in_progress is set to 1..
Index: linux-4.19.25-rt16/kernel/ptrace.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/ptrace.c
+++ linux-4.19.25-rt16/kernel/ptrace.c
@@ -175,7 +175,14 @@ static bool ptrace_freeze_traced(struct
 
 	spin_lock_irq(&task->sighand->siglock);
 	if (task_is_traced(task) && !__fatal_signal_pending(task)) {
-		task->state = __TASK_TRACED;
+		unsigned long flags;
+
+		raw_spin_lock_irqsave(&task->pi_lock, flags);
+		if (task->state & __TASK_TRACED)
+			task->state = __TASK_TRACED;
+		else
+			task->saved_state = __TASK_TRACED;
+		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 		ret = true;
 	}
 	spin_unlock_irq(&task->sighand->siglock);
Index: linux-4.19.25-rt16/kernel/rcu/Kconfig
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/Kconfig
+++ linux-4.19.25-rt16/kernel/rcu/Kconfig
@@ -172,7 +172,7 @@ config RCU_FANOUT_LEAF
 
 config RCU_FAST_NO_HZ
 	bool "Accelerate last non-dyntick-idle CPU's grace periods"
-	depends on NO_HZ_COMMON && SMP && RCU_EXPERT
+	depends on NO_HZ_COMMON && SMP && RCU_EXPERT && !PREEMPT_RT_FULL
 	default n
 	help
 	  This option permits CPUs to enter dynticks-idle state even if
@@ -190,8 +190,8 @@ config RCU_FAST_NO_HZ
 
 config RCU_BOOST
 	bool "Enable RCU priority boosting"
-	depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT
-	default n
+	depends on (RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT) || PREEMPT_RT_FULL
+	default y if PREEMPT_RT_FULL
 	help
 	  This option boosts the priority of preempted RCU readers that
 	  block the current preemptible RCU grace period for too long.
Index: linux-4.19.25-rt16/kernel/rcu/rcu.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/rcu.h
+++ linux-4.19.25-rt16/kernel/rcu/rcu.h
@@ -528,7 +528,6 @@ static inline void show_rcu_gp_kthreads(
 static inline int rcu_get_gp_kthreads_prio(void) { return 0; }
 #else /* #ifdef CONFIG_TINY_RCU */
 unsigned long rcu_get_gp_seq(void);
-unsigned long rcu_bh_get_gp_seq(void);
 unsigned long rcu_sched_get_gp_seq(void);
 unsigned long rcu_exp_batches_completed(void);
 unsigned long rcu_exp_batches_completed_sched(void);
@@ -536,10 +535,18 @@ unsigned long srcu_batches_completed(str
 void show_rcu_gp_kthreads(void);
 int rcu_get_gp_kthreads_prio(void);
 void rcu_force_quiescent_state(void);
-void rcu_bh_force_quiescent_state(void);
 void rcu_sched_force_quiescent_state(void);
 extern struct workqueue_struct *rcu_gp_wq;
 extern struct workqueue_struct *rcu_par_gp_wq;
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+#define rcu_bh_get_gp_seq		rcu_get_gp_seq
+#define rcu_bh_force_quiescent_state	rcu_force_quiescent_state
+#else
+unsigned long rcu_bh_get_gp_seq(void);
+void rcu_bh_force_quiescent_state(void);
+#endif
+
 #endif /* #else #ifdef CONFIG_TINY_RCU */
 
 #ifdef CONFIG_RCU_NOCB_CPU
Index: linux-4.19.25-rt16/kernel/rcu/rcutorture.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/rcutorture.c
+++ linux-4.19.25-rt16/kernel/rcu/rcutorture.c
@@ -434,6 +434,7 @@ static struct rcu_torture_ops rcu_ops =
 	.name		= "rcu"
 };
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Definitions for rcu_bh torture testing.
  */
@@ -475,6 +476,12 @@ static struct rcu_torture_ops rcu_bh_ops
 	.name		= "rcu_bh"
 };
 
+#else
+static struct rcu_torture_ops rcu_bh_ops = {
+	.ttype		= INVALID_RCU_FLAVOR,
+};
+#endif
+
 /*
  * Don't even think about trying any of these in real life!!!
  * The names includes "busted", and they really means it!
Index: linux-4.19.25-rt16/kernel/rcu/srcutree.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/srcutree.c
+++ linux-4.19.25-rt16/kernel/rcu/srcutree.c
@@ -38,6 +38,8 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/srcu.h>
+#include <linux/cpu.h>
+#include <linux/locallock.h>
 
 #include "rcu.h"
 #include "rcu_segcblist.h"
@@ -461,21 +463,6 @@ static void srcu_gp_start(struct srcu_st
 }
 
 /*
- * Track online CPUs to guide callback workqueue placement.
- */
-DEFINE_PER_CPU(bool, srcu_online);
-
-void srcu_online_cpu(unsigned int cpu)
-{
-	WRITE_ONCE(per_cpu(srcu_online, cpu), true);
-}
-
-void srcu_offline_cpu(unsigned int cpu)
-{
-	WRITE_ONCE(per_cpu(srcu_online, cpu), false);
-}
-
-/*
  * Place the workqueue handler on the specified CPU if online, otherwise
  * just run it whereever.  This is useful for placing workqueue handlers
  * that are to invoke the specified CPU's callbacks.
@@ -486,12 +473,12 @@ static bool srcu_queue_delayed_work_on(i
 {
 	bool ret;
 
-	preempt_disable();
-	if (READ_ONCE(per_cpu(srcu_online, cpu)))
+	cpus_read_lock();
+	if (cpu_online(cpu))
 		ret = queue_delayed_work_on(cpu, wq, dwork, delay);
 	else
 		ret = queue_delayed_work(wq, dwork, delay);
-	preempt_enable();
+	cpus_read_unlock();
 	return ret;
 }
 
@@ -774,6 +761,8 @@ static void srcu_flip(struct srcu_struct
  * negligible when amoritized over that time period, and the extra latency
  * of a needlessly non-expedited grace period is similarly negligible.
  */
+static DEFINE_LOCAL_IRQ_LOCK(sp_llock);
+
 static bool srcu_might_be_idle(struct srcu_struct *sp)
 {
 	unsigned long curseq;
@@ -782,13 +771,13 @@ static bool srcu_might_be_idle(struct sr
 	unsigned long t;
 
 	/* If the local srcu_data structure has callbacks, not idle.  */
-	local_irq_save(flags);
+	local_lock_irqsave(sp_llock, flags);
 	sdp = this_cpu_ptr(sp->sda);
 	if (rcu_segcblist_pend_cbs(&sdp->srcu_cblist)) {
-		local_irq_restore(flags);
+		local_unlock_irqrestore(sp_llock, flags);
 		return false; /* Callbacks already present, so not idle. */
 	}
-	local_irq_restore(flags);
+	local_unlock_irqrestore(sp_llock, flags);
 
 	/*
 	 * No local callbacks, so probabalistically probe global state.
@@ -866,7 +855,7 @@ void __call_srcu(struct srcu_struct *sp,
 		return;
 	}
 	rhp->func = func;
-	local_irq_save(flags);
+	local_lock_irqsave(sp_llock, flags);
 	sdp = this_cpu_ptr(sp->sda);
 	spin_lock_rcu_node(sdp);
 	rcu_segcblist_enqueue(&sdp->srcu_cblist, rhp, false);
@@ -882,7 +871,8 @@ void __call_srcu(struct srcu_struct *sp,
 		sdp->srcu_gp_seq_needed_exp = s;
 		needexp = true;
 	}
-	spin_unlock_irqrestore_rcu_node(sdp, flags);
+	spin_unlock_rcu_node(sdp);
+	local_unlock_irqrestore(sp_llock, flags);
 	if (needgp)
 		srcu_funnel_gp_start(sp, sdp, s, do_norm);
 	else if (needexp)
Index: linux-4.19.25-rt16/kernel/rcu/tree.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/tree.c
+++ linux-4.19.25-rt16/kernel/rcu/tree.c
@@ -61,6 +61,13 @@
 #include <linux/trace_events.h>
 #include <linux/suspend.h>
 #include <linux/ftrace.h>
+#include <linux/delay.h>
+#include <linux/gfp.h>
+#include <linux/oom.h>
+#include <linux/smpboot.h>
+#include <linux/jiffies.h>
+#include <linux/sched/isolation.h>
+#include "../time/tick-internal.h"
 
 #include "tree.h"
 #include "rcu.h"
@@ -244,6 +251,19 @@ void rcu_sched_qs(void)
 			   this_cpu_ptr(&rcu_sched_data), true);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void rcu_preempt_qs(void);
+
+void rcu_bh_qs(void)
+{
+	unsigned long flags;
+
+	/* Callers to this function, rcu_preempt_qs(), must disable irqs. */
+	local_irq_save(flags);
+	rcu_preempt_qs();
+	local_irq_restore(flags);
+}
+#else
 void rcu_bh_qs(void)
 {
 	RCU_LOCKDEP_WARN(preemptible(), "rcu_bh_qs() invoked with preemption enabled!!!");
@@ -254,6 +274,7 @@ void rcu_bh_qs(void)
 		__this_cpu_write(rcu_bh_data.cpu_no_qs.b.norm, false);
 	}
 }
+#endif
 
 /*
  * Steal a bit from the bottom of ->dynticks for idle entry/exit
@@ -568,6 +589,7 @@ unsigned long rcu_sched_get_gp_seq(void)
 }
 EXPORT_SYMBOL_GPL(rcu_sched_get_gp_seq);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Return the number of RCU-bh GPs completed thus far for debug & stats.
  */
@@ -576,6 +598,7 @@ unsigned long rcu_bh_get_gp_seq(void)
 	return READ_ONCE(rcu_bh_state.gp_seq);
 }
 EXPORT_SYMBOL_GPL(rcu_bh_get_gp_seq);
+#endif
 
 /*
  * Return the number of RCU expedited batches completed thus far for
@@ -599,6 +622,7 @@ unsigned long rcu_exp_batches_completed_
 }
 EXPORT_SYMBOL_GPL(rcu_exp_batches_completed_sched);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Force a quiescent state.
  */
@@ -617,6 +641,13 @@ void rcu_bh_force_quiescent_state(void)
 }
 EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state);
 
+#else
+void rcu_force_quiescent_state(void)
+{
+}
+EXPORT_SYMBOL_GPL(rcu_force_quiescent_state);
+#endif
+
 /*
  * Force a quiescent state for RCU-sched.
  */
@@ -674,9 +705,11 @@ void rcutorture_get_gp_data(enum rcutort
 	case RCU_FLAVOR:
 		rsp = rcu_state_p;
 		break;
+#ifndef CONFIG_PREEMPT_RT_FULL
 	case RCU_BH_FLAVOR:
 		rsp = &rcu_bh_state;
 		break;
+#endif
 	case RCU_SCHED_FLAVOR:
 		rsp = &rcu_sched_state;
 		break;
@@ -1263,6 +1296,7 @@ static int rcu_implicit_dynticks_qs(stru
 		    !rdp->rcu_iw_pending && rdp->rcu_iw_gp_seq != rnp->gp_seq &&
 		    (rnp->ffmask & rdp->grpmask)) {
 			init_irq_work(&rdp->rcu_iw, rcu_iw_handler);
+			rdp->rcu_iw.flags = IRQ_WORK_HARD_IRQ;
 			rdp->rcu_iw_pending = true;
 			rdp->rcu_iw_gp_seq = rnp->gp_seq;
 			irq_work_queue_on(&rdp->rcu_iw, rdp->cpu);
@@ -2870,18 +2904,17 @@ __rcu_process_callbacks(struct rcu_state
 /*
  * Do RCU core processing for the current CPU.
  */
-static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused)
+static __latent_entropy void rcu_process_callbacks(void)
 {
 	struct rcu_state *rsp;
 
 	if (cpu_is_offline(smp_processor_id()))
 		return;
-	trace_rcu_utilization(TPS("Start RCU core"));
 	for_each_rcu_flavor(rsp)
 		__rcu_process_callbacks(rsp);
-	trace_rcu_utilization(TPS("End RCU core"));
 }
 
+static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task);
 /*
  * Schedule RCU callback invocation.  If the specified type of RCU
  * does not support RCU priority boosting, just do a direct call,
@@ -2893,18 +2926,105 @@ static void invoke_rcu_callbacks(struct
 {
 	if (unlikely(!READ_ONCE(rcu_scheduler_fully_active)))
 		return;
-	if (likely(!rsp->boost)) {
-		rcu_do_batch(rsp, rdp);
+	rcu_do_batch(rsp, rdp);
+}
+
+static void rcu_wake_cond(struct task_struct *t, int status)
+{
+	/*
+	 * If the thread is yielding, only wake it when this
+	 * is invoked from idle
+	 */
+	if (t && (status != RCU_KTHREAD_YIELDING || is_idle_task(current)))
+		wake_up_process(t);
+}
+
+/*
+ * Wake up this CPU's rcuc kthread to do RCU core processing.
+ */
+static void invoke_rcu_core(void)
+{
+	unsigned long flags;
+	struct task_struct *t;
+
+	if (!cpu_online(smp_processor_id()))
 		return;
+	local_irq_save(flags);
+	__this_cpu_write(rcu_cpu_has_work, 1);
+	t = __this_cpu_read(rcu_cpu_kthread_task);
+	if (t != NULL && current != t)
+		rcu_wake_cond(t, __this_cpu_read(rcu_cpu_kthread_status));
+	local_irq_restore(flags);
+}
+
+static void rcu_cpu_kthread_park(unsigned int cpu)
+{
+	per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
+}
+
+static int rcu_cpu_kthread_should_run(unsigned int cpu)
+{
+	return __this_cpu_read(rcu_cpu_has_work);
+}
+
+/*
+ * Per-CPU kernel thread that invokes RCU callbacks.  This replaces the
+ * RCU softirq used in flavors and configurations of RCU that do not
+ * support RCU priority boosting.
+ */
+static void rcu_cpu_kthread(unsigned int cpu)
+{
+	unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status);
+	char work, *workp = this_cpu_ptr(&rcu_cpu_has_work);
+	int spincnt;
+
+	for (spincnt = 0; spincnt < 10; spincnt++) {
+		trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
+		local_bh_disable();
+		*statusp = RCU_KTHREAD_RUNNING;
+		this_cpu_inc(rcu_cpu_kthread_loops);
+		local_irq_disable();
+		work = *workp;
+		*workp = 0;
+		local_irq_enable();
+		if (work)
+			rcu_process_callbacks();
+		local_bh_enable();
+		if (*workp == 0) {
+			trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
+			*statusp = RCU_KTHREAD_WAITING;
+			return;
+		}
 	}
-	invoke_rcu_callbacks_kthread();
+	*statusp = RCU_KTHREAD_YIELDING;
+	trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
+	schedule_timeout_interruptible(2);
+	trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
+	*statusp = RCU_KTHREAD_WAITING;
 }
 
-static void invoke_rcu_core(void)
+static struct smp_hotplug_thread rcu_cpu_thread_spec = {
+	.store			= &rcu_cpu_kthread_task,
+	.thread_should_run	= rcu_cpu_kthread_should_run,
+	.thread_fn		= rcu_cpu_kthread,
+	.thread_comm		= "rcuc/%u",
+	.setup			= rcu_cpu_kthread_setup,
+	.park			= rcu_cpu_kthread_park,
+};
+
+/*
+ * Spawn per-CPU RCU core processing kthreads.
+ */
+static int __init rcu_spawn_core_kthreads(void)
 {
-	if (cpu_online(smp_processor_id()))
-		raise_softirq(RCU_SOFTIRQ);
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		per_cpu(rcu_cpu_has_work, cpu) = 0;
+	BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
+	return 0;
 }
+early_initcall(rcu_spawn_core_kthreads);
 
 /*
  * Handle any core-RCU processing required by a call_rcu() invocation.
@@ -3057,6 +3177,7 @@ void call_rcu_sched(struct rcu_head *hea
 }
 EXPORT_SYMBOL_GPL(call_rcu_sched);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /**
  * call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
  * @head: structure to be used for queueing the RCU updates.
@@ -3084,6 +3205,7 @@ void call_rcu_bh(struct rcu_head *head,
 	__call_rcu(head, func, &rcu_bh_state, -1, 0);
 }
 EXPORT_SYMBOL_GPL(call_rcu_bh);
+#endif
 
 /*
  * Queue an RCU callback for lazy invocation after a grace period.
@@ -3169,6 +3291,7 @@ void synchronize_sched(void)
 }
 EXPORT_SYMBOL_GPL(synchronize_sched);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /**
  * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
  *
@@ -3195,6 +3318,7 @@ void synchronize_rcu_bh(void)
 		wait_rcu_gp(call_rcu_bh);
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
+#endif
 
 /**
  * get_state_synchronize_rcu - Snapshot current RCU state
@@ -3502,6 +3626,7 @@ static void _rcu_barrier(struct rcu_stat
 	mutex_unlock(&rsp->barrier_mutex);
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /**
  * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
  */
@@ -3510,6 +3635,7 @@ void rcu_barrier_bh(void)
 	_rcu_barrier(&rcu_bh_state);
 }
 EXPORT_SYMBOL_GPL(rcu_barrier_bh);
+#endif
 
 /**
  * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
@@ -3659,8 +3785,6 @@ int rcutree_online_cpu(unsigned int cpu)
 		rnp->ffmask |= rdp->grpmask;
 		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	}
-	if (IS_ENABLED(CONFIG_TREE_SRCU))
-		srcu_online_cpu(cpu);
 	if (rcu_scheduler_active == RCU_SCHEDULER_INACTIVE)
 		return 0; /* Too early in boot for scheduler work. */
 	sync_sched_exp_online_cleanup(cpu);
@@ -3688,8 +3812,6 @@ int rcutree_offline_cpu(unsigned int cpu
 	}
 
 	rcutree_affinity_setting(cpu, cpu);
-	if (IS_ENABLED(CONFIG_TREE_SRCU))
-		srcu_offline_cpu(cpu);
 	return 0;
 }
 
@@ -4157,12 +4279,13 @@ void __init rcu_init(void)
 
 	rcu_bootup_announce();
 	rcu_init_geometry();
+#ifndef CONFIG_PREEMPT_RT_FULL
 	rcu_init_one(&rcu_bh_state);
+#endif
 	rcu_init_one(&rcu_sched_state);
 	if (dump_tree)
 		rcu_dump_rcu_node_tree(&rcu_sched_state);
 	__rcu_init_preempt();
-	open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
 
 	/*
 	 * We don't need protection against CPU-hotplug here because
Index: linux-4.19.25-rt16/kernel/rcu/tree.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/tree.h
+++ linux-4.19.25-rt16/kernel/rcu/tree.h
@@ -413,7 +413,9 @@ extern struct list_head rcu_struct_flavo
  */
 extern struct rcu_state rcu_sched_state;
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 extern struct rcu_state rcu_bh_state;
+#endif
 
 #ifdef CONFIG_PREEMPT_RCU
 extern struct rcu_state rcu_preempt_state;
@@ -421,12 +423,10 @@ extern struct rcu_state rcu_preempt_stat
 
 int rcu_dynticks_snap(struct rcu_dynticks *rdtp);
 
-#ifdef CONFIG_RCU_BOOST
 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
 DECLARE_PER_CPU(int, rcu_cpu_kthread_cpu);
 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
 DECLARE_PER_CPU(char, rcu_cpu_has_work);
-#endif /* #ifdef CONFIG_RCU_BOOST */
 
 #ifndef RCU_TREE_NONCORE
 
@@ -449,8 +449,8 @@ static void dump_blkd_tasks(struct rcu_s
 			    int ncheck);
 static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
 static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
-static void invoke_rcu_callbacks_kthread(void);
 static bool rcu_is_callbacks_kthread(void);
+static void rcu_cpu_kthread_setup(unsigned int cpu);
 #ifdef CONFIG_RCU_BOOST
 static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
 						 struct rcu_node *rnp);
Index: linux-4.19.25-rt16/kernel/rcu/tree_exp.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/tree_exp.h
+++ linux-4.19.25-rt16/kernel/rcu/tree_exp.h
@@ -472,7 +472,6 @@ retry_ipi:
 static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
 				     smp_call_func_t func)
 {
-	int cpu;
 	struct rcu_node *rnp;
 
 	trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("reset"));
@@ -494,13 +493,7 @@ static void sync_rcu_exp_select_cpus(str
 			continue;
 		}
 		INIT_WORK(&rnp->rew.rew_work, sync_rcu_exp_select_node_cpus);
-		preempt_disable();
-		cpu = cpumask_next(rnp->grplo - 1, cpu_online_mask);
-		/* If all offline, queue the work on an unbound CPU. */
-		if (unlikely(cpu > rnp->grphi))
-			cpu = WORK_CPU_UNBOUND;
-		queue_work_on(cpu, rcu_par_gp_wq, &rnp->rew.rew_work);
-		preempt_enable();
+		queue_work_on(rnp->grplo, rcu_par_gp_wq, &rnp->rew.rew_work);
 		rnp->exp_need_flush = true;
 	}
 
Index: linux-4.19.25-rt16/kernel/rcu/tree_plugin.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/tree_plugin.h
+++ linux-4.19.25-rt16/kernel/rcu/tree_plugin.h
@@ -24,41 +24,16 @@
  *	   Paul E. McKenney <paulmck@linux.vnet.ibm.com>
  */
 
-#include <linux/delay.h>
-#include <linux/gfp.h>
-#include <linux/oom.h>
-#include <linux/sched/debug.h>
-#include <linux/smpboot.h>
-#include <linux/sched/isolation.h>
-#include <uapi/linux/sched/types.h>
-#include "../time/tick-internal.h"
-
-#ifdef CONFIG_RCU_BOOST
-
 #include "../locking/rtmutex_common.h"
 
 /*
  * Control variables for per-CPU and per-rcu_node kthreads.  These
  * handle all flavors of RCU.
  */
-static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task);
 DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
 DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
 DEFINE_PER_CPU(char, rcu_cpu_has_work);
 
-#else /* #ifdef CONFIG_RCU_BOOST */
-
-/*
- * Some architectures do not define rt_mutexes, but if !CONFIG_RCU_BOOST,
- * all uses are in dead code.  Provide a definition to keep the compiler
- * happy, but add WARN_ON_ONCE() to complain if used in the wrong place.
- * This probably needs to be excluded from -rt builds.
- */
-#define rt_mutex_owner(a) ({ WARN_ON_ONCE(1); NULL; })
-#define rt_mutex_futex_unlock(x) WARN_ON_ONCE(1)
-
-#endif /* #else #ifdef CONFIG_RCU_BOOST */
-
 #ifdef CONFIG_RCU_NOCB_CPU
 static cpumask_var_t rcu_nocb_mask; /* CPUs to have callbacks offloaded. */
 static bool __read_mostly rcu_nocb_poll;    /* Offload kthread are to poll. */
@@ -337,9 +312,13 @@ static void rcu_preempt_note_context_swi
 	struct task_struct *t = current;
 	struct rcu_data *rdp;
 	struct rcu_node *rnp;
+	int sleeping_l = 0;
 
 	lockdep_assert_irqs_disabled();
-	WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0);
+#if defined(CONFIG_PREEMPT_RT_FULL)
+	sleeping_l = t->sleeping_lock;
+#endif
+	WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0 && !sleeping_l);
 	if (t->rcu_read_lock_nesting > 0 &&
 	    !t->rcu_read_unlock_special.b.blocked) {
 
@@ -520,7 +499,7 @@ static void rcu_read_unlock_special(stru
 	}
 
 	/* Hardware IRQ handlers cannot block, complain if they get here. */
-	if (in_irq() || in_serving_softirq()) {
+	if (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET)) {
 		lockdep_rcu_suspicious(__FILE__, __LINE__,
 				       "rcu_read_unlock() from irq or softirq with blocking in critical section!!!\n");
 		pr_alert("->rcu_read_unlock_special: %#x (b: %d, enq: %d nq: %d)\n",
@@ -1022,18 +1001,21 @@ dump_blkd_tasks(struct rcu_state *rsp, s
 
 #endif /* #else #ifdef CONFIG_PREEMPT_RCU */
 
+/*
+ * If boosting, set rcuc kthreads to realtime priority.
+ */
+static void rcu_cpu_kthread_setup(unsigned int cpu)
+{
 #ifdef CONFIG_RCU_BOOST
+	struct sched_param sp;
 
-static void rcu_wake_cond(struct task_struct *t, int status)
-{
-	/*
-	 * If the thread is yielding, only wake it when this
-	 * is invoked from idle
-	 */
-	if (status != RCU_KTHREAD_YIELDING || is_idle_task(current))
-		wake_up_process(t);
+	sp.sched_priority = kthread_prio;
+	sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
+#endif /* #ifdef CONFIG_RCU_BOOST */
 }
 
+#ifdef CONFIG_RCU_BOOST
+
 /*
  * Carry out RCU priority boosting on the task indicated by ->exp_tasks
  * or ->boost_tasks, advancing the pointer to the next task in the
@@ -1172,23 +1154,6 @@ static void rcu_initiate_boost(struct rc
 }
 
 /*
- * Wake up the per-CPU kthread to invoke RCU callbacks.
- */
-static void invoke_rcu_callbacks_kthread(void)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	__this_cpu_write(rcu_cpu_has_work, 1);
-	if (__this_cpu_read(rcu_cpu_kthread_task) != NULL &&
-	    current != __this_cpu_read(rcu_cpu_kthread_task)) {
-		rcu_wake_cond(__this_cpu_read(rcu_cpu_kthread_task),
-			      __this_cpu_read(rcu_cpu_kthread_status));
-	}
-	local_irq_restore(flags);
-}
-
-/*
  * Is the current CPU running the RCU-callbacks kthread?
  * Caller must have preemption disabled.
  */
@@ -1242,67 +1207,6 @@ static int rcu_spawn_one_boost_kthread(s
 	return 0;
 }
 
-static void rcu_kthread_do_work(void)
-{
-	rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
-	rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
-	rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
-}
-
-static void rcu_cpu_kthread_setup(unsigned int cpu)
-{
-	struct sched_param sp;
-
-	sp.sched_priority = kthread_prio;
-	sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
-}
-
-static void rcu_cpu_kthread_park(unsigned int cpu)
-{
-	per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
-}
-
-static int rcu_cpu_kthread_should_run(unsigned int cpu)
-{
-	return __this_cpu_read(rcu_cpu_has_work);
-}
-
-/*
- * Per-CPU kernel thread that invokes RCU callbacks.  This replaces the
- * RCU softirq used in flavors and configurations of RCU that do not
- * support RCU priority boosting.
- */
-static void rcu_cpu_kthread(unsigned int cpu)
-{
-	unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status);
-	char work, *workp = this_cpu_ptr(&rcu_cpu_has_work);
-	int spincnt;
-
-	for (spincnt = 0; spincnt < 10; spincnt++) {
-		trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
-		local_bh_disable();
-		*statusp = RCU_KTHREAD_RUNNING;
-		this_cpu_inc(rcu_cpu_kthread_loops);
-		local_irq_disable();
-		work = *workp;
-		*workp = 0;
-		local_irq_enable();
-		if (work)
-			rcu_kthread_do_work();
-		local_bh_enable();
-		if (*workp == 0) {
-			trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
-			*statusp = RCU_KTHREAD_WAITING;
-			return;
-		}
-	}
-	*statusp = RCU_KTHREAD_YIELDING;
-	trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
-	schedule_timeout_interruptible(2);
-	trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
-	*statusp = RCU_KTHREAD_WAITING;
-}
-
 /*
  * Set the per-rcu_node kthread's affinity to cover all CPUs that are
  * served by the rcu_node in question.  The CPU hotplug lock is still
@@ -1333,26 +1237,12 @@ static void rcu_boost_kthread_setaffinit
 	free_cpumask_var(cm);
 }
 
-static struct smp_hotplug_thread rcu_cpu_thread_spec = {
-	.store			= &rcu_cpu_kthread_task,
-	.thread_should_run	= rcu_cpu_kthread_should_run,
-	.thread_fn		= rcu_cpu_kthread,
-	.thread_comm		= "rcuc/%u",
-	.setup			= rcu_cpu_kthread_setup,
-	.park			= rcu_cpu_kthread_park,
-};
-
 /*
  * Spawn boost kthreads -- called as soon as the scheduler is running.
  */
 static void __init rcu_spawn_boost_kthreads(void)
 {
 	struct rcu_node *rnp;
-	int cpu;
-
-	for_each_possible_cpu(cpu)
-		per_cpu(rcu_cpu_has_work, cpu) = 0;
-	BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
 	rcu_for_each_leaf_node(rcu_state_p, rnp)
 		(void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp);
 }
@@ -1375,11 +1265,6 @@ static void rcu_initiate_boost(struct rc
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 }
 
-static void invoke_rcu_callbacks_kthread(void)
-{
-	WARN_ON_ONCE(1);
-}
-
 static bool rcu_is_callbacks_kthread(void)
 {
 	return false;
@@ -1403,7 +1288,7 @@ static void rcu_prepare_kthreads(int cpu
 
 #endif /* #else #ifdef CONFIG_RCU_BOOST */
 
-#if !defined(CONFIG_RCU_FAST_NO_HZ)
+#if !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL)
 
 /*
  * Check to see if any future RCU-related work will need to be done
@@ -1419,7 +1304,9 @@ int rcu_needs_cpu(u64 basemono, u64 *nex
 	*nextevt = KTIME_MAX;
 	return rcu_cpu_has_callbacks(NULL);
 }
+#endif /* !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL) */
 
+#if !defined(CONFIG_RCU_FAST_NO_HZ)
 /*
  * Because we do not have RCU_FAST_NO_HZ, don't bother cleaning up
  * after it.
@@ -1516,6 +1403,8 @@ static bool __maybe_unused rcu_try_advan
 	return cbs_ready;
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 /*
  * Allow the CPU to enter dyntick-idle mode unless it has callbacks ready
  * to invoke.  If the CPU has callbacks, try to advance them.  Tell the
@@ -1558,6 +1447,7 @@ int rcu_needs_cpu(u64 basemono, u64 *nex
 	*nextevt = basemono + dj * TICK_NSEC;
 	return 0;
 }
+#endif /* #ifndef CONFIG_PREEMPT_RT_FULL */
 
 /*
  * Prepare a CPU for idle from an RCU perspective.  The first major task
Index: linux-4.19.25-rt16/kernel/rcu/update.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/rcu/update.c
+++ linux-4.19.25-rt16/kernel/rcu/update.c
@@ -68,7 +68,7 @@ extern int rcu_expedited; /* from sysctl
 module_param(rcu_expedited, int, 0);
 extern int rcu_normal; /* from sysctl */
 module_param(rcu_normal, int, 0);
-static int rcu_normal_after_boot;
+static int rcu_normal_after_boot = IS_ENABLED(CONFIG_PREEMPT_RT_FULL);
 module_param(rcu_normal_after_boot, int, 0);
 #endif /* #ifndef CONFIG_TINY_RCU */
 
@@ -288,6 +288,7 @@ int rcu_read_lock_held(void)
 }
 EXPORT_SYMBOL_GPL(rcu_read_lock_held);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /**
  * rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
  *
@@ -314,6 +315,7 @@ int rcu_read_lock_bh_held(void)
 	return in_softirq() || irqs_disabled();
 }
 EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
+#endif
 
 #endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
 
Index: linux-4.19.25-rt16/kernel/sched/Makefile
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/Makefile
+++ linux-4.19.25-rt16/kernel/sched/Makefile
@@ -18,7 +18,7 @@ endif
 
 obj-y += core.o loadavg.o clock.o cputime.o
 obj-y += idle.o fair.o rt.o deadline.o
-obj-y += wait.o wait_bit.o swait.o completion.o
+obj-y += wait.o wait_bit.o swait.o swork.o completion.o
 
 obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o pelt.o
 obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o
Index: linux-4.19.25-rt16/kernel/sched/completion.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/completion.c
+++ linux-4.19.25-rt16/kernel/sched/completion.c
@@ -29,12 +29,12 @@ void complete(struct completion *x)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 
 	if (x->done != UINT_MAX)
 		x->done++;
-	__wake_up_locked(&x->wait, TASK_NORMAL, 1);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	swake_up_locked(&x->wait);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 }
 EXPORT_SYMBOL(complete);
 
@@ -58,10 +58,10 @@ void complete_all(struct completion *x)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	x->done = UINT_MAX;
-	__wake_up_locked(&x->wait, TASK_NORMAL, 0);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	swake_up_all_locked(&x->wait);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 }
 EXPORT_SYMBOL(complete_all);
 
@@ -70,20 +70,20 @@ do_wait_for_common(struct completion *x,
 		   long (*action)(long), long timeout, int state)
 {
 	if (!x->done) {
-		DECLARE_WAITQUEUE(wait, current);
+		DECLARE_SWAITQUEUE(wait);
 
-		__add_wait_queue_entry_tail_exclusive(&x->wait, &wait);
 		do {
 			if (signal_pending_state(state, current)) {
 				timeout = -ERESTARTSYS;
 				break;
 			}
+			__prepare_to_swait(&x->wait, &wait);
 			__set_current_state(state);
-			spin_unlock_irq(&x->wait.lock);
+			raw_spin_unlock_irq(&x->wait.lock);
 			timeout = action(timeout);
-			spin_lock_irq(&x->wait.lock);
+			raw_spin_lock_irq(&x->wait.lock);
 		} while (!x->done && timeout);
-		__remove_wait_queue(&x->wait, &wait);
+		__finish_swait(&x->wait, &wait);
 		if (!x->done)
 			return timeout;
 	}
@@ -100,9 +100,9 @@ __wait_for_common(struct completion *x,
 
 	complete_acquire(x);
 
-	spin_lock_irq(&x->wait.lock);
+	raw_spin_lock_irq(&x->wait.lock);
 	timeout = do_wait_for_common(x, action, timeout, state);
-	spin_unlock_irq(&x->wait.lock);
+	raw_spin_unlock_irq(&x->wait.lock);
 
 	complete_release(x);
 
@@ -291,12 +291,12 @@ bool try_wait_for_completion(struct comp
 	if (!READ_ONCE(x->done))
 		return false;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	if (!x->done)
 		ret = false;
 	else if (x->done != UINT_MAX)
 		x->done--;
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(try_wait_for_completion);
@@ -322,8 +322,8 @@ bool completion_done(struct completion *
 	 * otherwise we can end up freeing the completion before complete()
 	 * is done referencing it.
 	 */
-	spin_lock_irqsave(&x->wait.lock, flags);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 	return true;
 }
 EXPORT_SYMBOL(completion_done);
Index: linux-4.19.25-rt16/kernel/sched/core.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/core.c
+++ linux-4.19.25-rt16/kernel/sched/core.c
@@ -44,7 +44,11 @@ const_debug unsigned int sysctl_sched_fe
  * Number of tasks to iterate in a single balance run.
  * Limited because this is done with IRQs disabled.
  */
+#ifdef CONFIG_PREEMPT_RT_FULL
+const_debug unsigned int sysctl_sched_nr_migrate = 8;
+#else
 const_debug unsigned int sysctl_sched_nr_migrate = 32;
+#endif
 
 /*
  * period over which we measure -rt task CPU usage in us.
@@ -315,7 +319,7 @@ static void hrtick_rq_init(struct rq *rq
 	rq->hrtick_csd.info = rq;
 #endif
 
-	hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	rq->hrtick_timer.function = hrtick;
 }
 #else	/* CONFIG_SCHED_HRTICK */
@@ -397,9 +401,15 @@ static bool set_nr_if_polling(struct tas
 #endif
 #endif
 
-void wake_q_add(struct wake_q_head *head, struct task_struct *task)
+void __wake_q_add(struct wake_q_head *head, struct task_struct *task,
+		  bool sleeper)
 {
-	struct wake_q_node *node = &task->wake_q;
+	struct wake_q_node *node;
+
+	if (sleeper)
+		node = &task->wake_q_sleeper;
+	else
+		node = &task->wake_q;
 
 	/*
 	 * Atomically grab the task, if ->wake_q is !nil already it means
@@ -422,24 +432,32 @@ void wake_q_add(struct wake_q_head *head
 	head->lastp = &node->next;
 }
 
-void wake_up_q(struct wake_q_head *head)
+void __wake_up_q(struct wake_q_head *head, bool sleeper)
 {
 	struct wake_q_node *node = head->first;
 
 	while (node != WAKE_Q_TAIL) {
 		struct task_struct *task;
 
-		task = container_of(node, struct task_struct, wake_q);
+		if (sleeper)
+			task = container_of(node, struct task_struct, wake_q_sleeper);
+		else
+			task = container_of(node, struct task_struct, wake_q);
 		BUG_ON(!task);
 		/* Task can safely be re-inserted now: */
 		node = node->next;
-		task->wake_q.next = NULL;
-
+		if (sleeper)
+			task->wake_q_sleeper.next = NULL;
+		else
+			task->wake_q.next = NULL;
 		/*
 		 * wake_up_process() executes a full barrier, which pairs with
 		 * the queueing in wake_q_add() so as not to miss wakeups.
 		 */
-		wake_up_process(task);
+		if (sleeper)
+			wake_up_lock_sleeper(task);
+		else
+			wake_up_process(task);
 		put_task_struct(task);
 	}
 }
@@ -475,6 +493,48 @@ void resched_curr(struct rq *rq)
 		trace_sched_wake_idle_without_ipi(cpu);
 }
 
+#ifdef CONFIG_PREEMPT_LAZY
+
+static int tsk_is_polling(struct task_struct *p)
+{
+#ifdef TIF_POLLING_NRFLAG
+	return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
+#else
+	return 0;
+#endif
+}
+
+void resched_curr_lazy(struct rq *rq)
+{
+	struct task_struct *curr = rq->curr;
+	int cpu;
+
+	if (!sched_feat(PREEMPT_LAZY)) {
+		resched_curr(rq);
+		return;
+	}
+
+	lockdep_assert_held(&rq->lock);
+
+	if (test_tsk_need_resched(curr))
+		return;
+
+	if (test_tsk_need_resched_lazy(curr))
+		return;
+
+	set_tsk_need_resched_lazy(curr);
+
+	cpu = cpu_of(rq);
+	if (cpu == smp_processor_id())
+		return;
+
+	/* NEED_RESCHED_LAZY must be visible before we test polling */
+	smp_mb();
+	if (!tsk_is_polling(curr))
+		smp_send_reschedule(cpu);
+}
+#endif
+
 void resched_cpu(int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
@@ -498,11 +558,14 @@ void resched_cpu(int cpu)
  */
 int get_nohz_timer_target(void)
 {
-	int i, cpu = smp_processor_id();
+	int i, cpu;
 	struct sched_domain *sd;
 
+	preempt_disable_rt();
+	cpu = smp_processor_id();
+
 	if (!idle_cpu(cpu) && housekeeping_cpu(cpu, HK_FLAG_TIMER))
-		return cpu;
+		goto preempt_en_rt;
 
 	rcu_read_lock();
 	for_each_domain(cpu, sd) {
@@ -521,6 +584,8 @@ int get_nohz_timer_target(void)
 		cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
 unlock:
 	rcu_read_unlock();
+preempt_en_rt:
+	preempt_enable_rt();
 	return cpu;
 }
 
@@ -878,10 +943,10 @@ static inline bool is_per_cpu_kthread(st
  */
 static inline bool is_cpu_allowed(struct task_struct *p, int cpu)
 {
-	if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
+	if (!cpumask_test_cpu(cpu, p->cpus_ptr))
 		return false;
 
-	if (is_per_cpu_kthread(p))
+	if (is_per_cpu_kthread(p) || __migrate_disabled(p))
 		return cpu_online(cpu);
 
 	return cpu_active(cpu);
@@ -973,7 +1038,7 @@ static int migration_cpu_stop(void *data
 	local_irq_disable();
 	/*
 	 * We need to explicitly wake pending tasks before running
-	 * __migrate_task() such that we will not miss enforcing cpus_allowed
+	 * __migrate_task() such that we will not miss enforcing cpus_ptr
 	 * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test.
 	 */
 	sched_ttwu_pending();
@@ -1004,11 +1069,20 @@ static int migration_cpu_stop(void *data
  */
 void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask)
 {
-	cpumask_copy(&p->cpus_allowed, new_mask);
+	cpumask_copy(&p->cpus_mask, new_mask);
 	p->nr_cpus_allowed = cpumask_weight(new_mask);
 }
 
-void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
+#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+int __migrate_disabled(struct task_struct *p)
+{
+	return p->migrate_disable;
+}
+EXPORT_SYMBOL_GPL(__migrate_disabled);
+#endif
+
+static void __do_set_cpus_allowed_tail(struct task_struct *p,
+				       const struct cpumask *new_mask)
 {
 	struct rq *rq = task_rq(p);
 	bool queued, running;
@@ -1037,6 +1111,20 @@ void do_set_cpus_allowed(struct task_str
 		set_curr_task(rq, p);
 }
 
+void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
+{
+#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+	if (__migrate_disabled(p)) {
+		lockdep_assert_held(&p->pi_lock);
+
+		cpumask_copy(&p->cpus_mask, new_mask);
+		p->migrate_disable_update = 1;
+		return;
+	}
+#endif
+	__do_set_cpus_allowed_tail(p, new_mask);
+}
+
 /*
  * Change a given task's CPU affinity. Migrate the thread to a
  * proper CPU and schedule it away if the CPU it's executing on
@@ -1074,7 +1162,7 @@ static int __set_cpus_allowed_ptr(struct
 		goto out;
 	}
 
-	if (cpumask_equal(&p->cpus_allowed, new_mask))
+	if (cpumask_equal(p->cpus_ptr, new_mask))
 		goto out;
 
 	if (!cpumask_intersects(new_mask, cpu_valid_mask)) {
@@ -1095,9 +1183,16 @@ static int __set_cpus_allowed_ptr(struct
 	}
 
 	/* Can the task run on the task's current CPU? If so, we're done */
-	if (cpumask_test_cpu(task_cpu(p), new_mask))
+	if (cpumask_test_cpu(task_cpu(p), new_mask) || __migrate_disabled(p))
 		goto out;
 
+#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+	if (__migrate_disabled(p)) {
+		p->migrate_disable_update = 1;
+		goto out;
+	}
+#endif
+
 	dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask);
 	if (task_running(rq, p) || p->state == TASK_WAKING) {
 		struct migration_arg arg = { p, dest_cpu };
@@ -1237,10 +1332,10 @@ static int migrate_swap_stop(void *data)
 	if (task_cpu(arg->src_task) != arg->src_cpu)
 		goto unlock;
 
-	if (!cpumask_test_cpu(arg->dst_cpu, &arg->src_task->cpus_allowed))
+	if (!cpumask_test_cpu(arg->dst_cpu, arg->src_task->cpus_ptr))
 		goto unlock;
 
-	if (!cpumask_test_cpu(arg->src_cpu, &arg->dst_task->cpus_allowed))
+	if (!cpumask_test_cpu(arg->src_cpu, arg->dst_task->cpus_ptr))
 		goto unlock;
 
 	__migrate_swap_task(arg->src_task, arg->dst_cpu);
@@ -1282,10 +1377,10 @@ int migrate_swap(struct task_struct *cur
 	if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu))
 		goto out;
 
-	if (!cpumask_test_cpu(arg.dst_cpu, &arg.src_task->cpus_allowed))
+	if (!cpumask_test_cpu(arg.dst_cpu, arg.src_task->cpus_ptr))
 		goto out;
 
-	if (!cpumask_test_cpu(arg.src_cpu, &arg.dst_task->cpus_allowed))
+	if (!cpumask_test_cpu(arg.src_cpu, arg.dst_task->cpus_ptr))
 		goto out;
 
 	trace_sched_swap_numa(cur, arg.src_cpu, p, arg.dst_cpu);
@@ -1296,6 +1391,18 @@ out:
 }
 #endif /* CONFIG_NUMA_BALANCING */
 
+static bool check_task_state(struct task_struct *p, long match_state)
+{
+	bool match = false;
+
+	raw_spin_lock_irq(&p->pi_lock);
+	if (p->state == match_state || p->saved_state == match_state)
+		match = true;
+	raw_spin_unlock_irq(&p->pi_lock);
+
+	return match;
+}
+
 /*
  * wait_task_inactive - wait for a thread to unschedule.
  *
@@ -1340,7 +1447,7 @@ unsigned long wait_task_inactive(struct
 		 * is actually now running somewhere else!
 		 */
 		while (task_running(rq, p)) {
-			if (match_state && unlikely(p->state != match_state))
+			if (match_state && !check_task_state(p, match_state))
 				return 0;
 			cpu_relax();
 		}
@@ -1355,7 +1462,8 @@ unsigned long wait_task_inactive(struct
 		running = task_running(rq, p);
 		queued = task_on_rq_queued(p);
 		ncsw = 0;
-		if (!match_state || p->state == match_state)
+		if (!match_state || p->state == match_state ||
+		    p->saved_state == match_state)
 			ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
 		task_rq_unlock(rq, p, &rf);
 
@@ -1430,7 +1538,7 @@ void kick_process(struct task_struct *p)
 EXPORT_SYMBOL_GPL(kick_process);
 
 /*
- * ->cpus_allowed is protected by both rq->lock and p->pi_lock
+ * ->cpus_ptr is protected by both rq->lock and p->pi_lock
  *
  * A few notes on cpu_active vs cpu_online:
  *
@@ -1470,14 +1578,14 @@ static int select_fallback_rq(int cpu, s
 		for_each_cpu(dest_cpu, nodemask) {
 			if (!cpu_active(dest_cpu))
 				continue;
-			if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
+			if (cpumask_test_cpu(dest_cpu, p->cpus_ptr))
 				return dest_cpu;
 		}
 	}
 
 	for (;;) {
 		/* Any allowed, online CPU? */
-		for_each_cpu(dest_cpu, &p->cpus_allowed) {
+		for_each_cpu(dest_cpu, p->cpus_ptr) {
 			if (!is_cpu_allowed(p, dest_cpu))
 				continue;
 
@@ -1521,7 +1629,7 @@ out:
 }
 
 /*
- * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
+ * The caller (fork, wakeup) owns p->pi_lock, ->cpus_ptr is stable.
  */
 static inline
 int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags)
@@ -1531,11 +1639,11 @@ int select_task_rq(struct task_struct *p
 	if (p->nr_cpus_allowed > 1)
 		cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags);
 	else
-		cpu = cpumask_any(&p->cpus_allowed);
+		cpu = cpumask_any(p->cpus_ptr);
 
 	/*
 	 * In order not to call set_task_cpu() on a blocking task we need
-	 * to rely on ttwu() to place the task on a valid ->cpus_allowed
+	 * to rely on ttwu() to place the task on a valid ->cpus_ptr
 	 * CPU.
 	 *
 	 * Since this is common to all placement strategies, this lives here.
@@ -1638,10 +1746,6 @@ static inline void ttwu_activate(struct
 {
 	activate_task(rq, p, en_flags);
 	p->on_rq = TASK_ON_RQ_QUEUED;
-
-	/* If a worker is waking up, notify the workqueue: */
-	if (p->flags & PF_WQ_WORKER)
-		wq_worker_waking_up(p, cpu_of(rq));
 }
 
 /*
@@ -1960,8 +2064,27 @@ try_to_wake_up(struct task_struct *p, un
 	 */
 	raw_spin_lock_irqsave(&p->pi_lock, flags);
 	smp_mb__after_spinlock();
-	if (!(p->state & state))
+	if (!(p->state & state)) {
+		/*
+		 * The task might be running due to a spinlock sleeper
+		 * wakeup. Check the saved state and set it to running
+		 * if the wakeup condition is true.
+		 */
+		if (!(wake_flags & WF_LOCK_SLEEPER)) {
+			if (p->saved_state & state) {
+				p->saved_state = TASK_RUNNING;
+				success = 1;
+			}
+		}
 		goto out;
+	}
+
+	/*
+	 * If this is a regular wakeup, then we can unconditionally
+	 * clear the saved state of a "lock sleeper".
+	 */
+	if (!(wake_flags & WF_LOCK_SLEEPER))
+		p->saved_state = TASK_RUNNING;
 
 	trace_sched_waking(p);
 
@@ -2059,56 +2182,6 @@ out:
 }
 
 /**
- * try_to_wake_up_local - try to wake up a local task with rq lock held
- * @p: the thread to be awakened
- * @rf: request-queue flags for pinning
- *
- * Put @p on the run-queue if it's not already there. The caller must
- * ensure that this_rq() is locked, @p is bound to this_rq() and not
- * the current task.
- */
-static void try_to_wake_up_local(struct task_struct *p, struct rq_flags *rf)
-{
-	struct rq *rq = task_rq(p);
-
-	if (WARN_ON_ONCE(rq != this_rq()) ||
-	    WARN_ON_ONCE(p == current))
-		return;
-
-	lockdep_assert_held(&rq->lock);
-
-	if (!raw_spin_trylock(&p->pi_lock)) {
-		/*
-		 * This is OK, because current is on_cpu, which avoids it being
-		 * picked for load-balance and preemption/IRQs are still
-		 * disabled avoiding further scheduler activity on it and we've
-		 * not yet picked a replacement task.
-		 */
-		rq_unlock(rq, rf);
-		raw_spin_lock(&p->pi_lock);
-		rq_relock(rq, rf);
-	}
-
-	if (!(p->state & TASK_NORMAL))
-		goto out;
-
-	trace_sched_waking(p);
-
-	if (!task_on_rq_queued(p)) {
-		if (p->in_iowait) {
-			delayacct_blkio_end(p);
-			atomic_dec(&rq->nr_iowait);
-		}
-		ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK);
-	}
-
-	ttwu_do_wakeup(rq, p, 0, rf);
-	ttwu_stat(p, smp_processor_id(), 0);
-out:
-	raw_spin_unlock(&p->pi_lock);
-}
-
-/**
  * wake_up_process - Wake up a specific process
  * @p: The process to be woken up.
  *
@@ -2125,6 +2198,18 @@ int wake_up_process(struct task_struct *
 }
 EXPORT_SYMBOL(wake_up_process);
 
+/**
+ * wake_up_lock_sleeper - Wake up a specific process blocked on a "sleeping lock"
+ * @p: The process to be woken up.
+ *
+ * Same as wake_up_process() above, but wake_flags=WF_LOCK_SLEEPER to indicate
+ * the nature of the wakeup.
+ */
+int wake_up_lock_sleeper(struct task_struct *p)
+{
+	return try_to_wake_up(p, TASK_UNINTERRUPTIBLE, WF_LOCK_SLEEPER);
+}
+
 int wake_up_state(struct task_struct *p, unsigned int state)
 {
 	return try_to_wake_up(p, state, 0);
@@ -2362,6 +2447,9 @@ int sched_fork(unsigned long clone_flags
 	p->on_cpu = 0;
 #endif
 	init_task_preempt_count(p);
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+	task_thread_info(p)->preempt_lazy_count = 0;
+#endif
 #ifdef CONFIG_SMP
 	plist_node_init(&p->pushable_tasks, MAX_PRIO);
 	RB_CLEAR_NODE(&p->pushable_dl_tasks);
@@ -2402,7 +2490,7 @@ void wake_up_new_task(struct task_struct
 #ifdef CONFIG_SMP
 	/*
 	 * Fork balancing, do it here and not earlier because:
-	 *  - cpus_allowed can change in the fork path
+	 *  - cpus_ptr can change in the fork path
 	 *  - any previously selected CPU might disappear through hotplug
 	 *
 	 * Use __set_task_cpu() to avoid calling sched_class::migrate_task_rq,
@@ -2690,23 +2778,18 @@ static struct rq *finish_task_switch(str
 	 *   provided by mmdrop(),
 	 * - a sync_core for SYNC_CORE.
 	 */
+	/*
+	 * We use mmdrop_delayed() here so we don't have to do the
+	 * full __mmdrop() when we are the last user.
+	 */
 	if (mm) {
 		membarrier_mm_sync_core_before_usermode(mm);
-		mmdrop(mm);
+		mmdrop_delayed(mm);
 	}
 	if (unlikely(prev_state == TASK_DEAD)) {
 		if (prev->sched_class->task_dead)
 			prev->sched_class->task_dead(prev);
 
-		/*
-		 * Remove function-return probe instances associated with this
-		 * task and put them back on the free list.
-		 */
-		kprobe_flush_task(prev);
-
-		/* Task is done with its stack. */
-		put_task_stack(prev);
-
 		put_task_struct(prev);
 	}
 
@@ -3428,25 +3511,13 @@ static void __sched notrace __schedule(b
 				atomic_inc(&rq->nr_iowait);
 				delayacct_blkio_start();
 			}
-
-			/*
-			 * If a worker went to sleep, notify and ask workqueue
-			 * whether it wants to wake up a task to maintain
-			 * concurrency.
-			 */
-			if (prev->flags & PF_WQ_WORKER) {
-				struct task_struct *to_wakeup;
-
-				to_wakeup = wq_worker_sleeping(prev);
-				if (to_wakeup)
-					try_to_wake_up_local(to_wakeup, &rf);
-			}
 		}
 		switch_count = &prev->nvcsw;
 	}
 
 	next = pick_next_task(rq, prev, &rf);
 	clear_tsk_need_resched(prev);
+	clear_tsk_need_resched_lazy(prev);
 	clear_preempt_need_resched();
 
 	if (likely(prev != next)) {
@@ -3498,8 +3569,24 @@ void __noreturn do_task_dead(void)
 
 static inline void sched_submit_work(struct task_struct *tsk)
 {
-	if (!tsk->state || tsk_is_pi_blocked(tsk))
+	if (!tsk->state)
+		return;
+	/*
+	 * If a worker went to sleep, notify and ask workqueue whether
+	 * it wants to wake up a task to maintain concurrency.
+	 * As this function is called inside the schedule() context,
+	 * we disable preemption to avoid it calling schedule() again
+	 * in the possible wakeup of a kworker.
+	 */
+	if (tsk->flags & PF_WQ_WORKER) {
+		preempt_disable();
+		wq_worker_sleeping(tsk);
+		preempt_enable_no_resched();
+	}
+
+	if (tsk_is_pi_blocked(tsk))
 		return;
+
 	/*
 	 * If we are going to sleep and we have plugged IO queued,
 	 * make sure to submit it to avoid deadlocks.
@@ -3508,6 +3595,12 @@ static inline void sched_submit_work(str
 		blk_schedule_flush_plug(tsk);
 }
 
+static void sched_update_worker(struct task_struct *tsk)
+{
+	if (tsk->flags & PF_WQ_WORKER)
+		wq_worker_running(tsk);
+}
+
 asmlinkage __visible void __sched schedule(void)
 {
 	struct task_struct *tsk = current;
@@ -3518,6 +3611,7 @@ asmlinkage __visible void __sched schedu
 		__schedule(false);
 		sched_preempt_enable_no_resched();
 	} while (need_resched());
+	sched_update_worker(tsk);
 }
 EXPORT_SYMBOL(schedule);
 
@@ -3606,6 +3700,30 @@ static void __sched notrace preempt_sche
 	} while (need_resched());
 }
 
+#ifdef CONFIG_PREEMPT_LAZY
+/*
+ * If TIF_NEED_RESCHED is then we allow to be scheduled away since this is
+ * set by a RT task. Oterwise we try to avoid beeing scheduled out as long as
+ * preempt_lazy_count counter >0.
+ */
+static __always_inline int preemptible_lazy(void)
+{
+	if (test_thread_flag(TIF_NEED_RESCHED))
+		return 1;
+	if (current_thread_info()->preempt_lazy_count)
+		return 0;
+	return 1;
+}
+
+#else
+
+static inline int preemptible_lazy(void)
+{
+	return 1;
+}
+
+#endif
+
 #ifdef CONFIG_PREEMPT
 /*
  * this is the entry point to schedule() from in-kernel preemption
@@ -3620,7 +3738,8 @@ asmlinkage __visible void __sched notrac
 	 */
 	if (likely(!preemptible()))
 		return;
-
+	if (!preemptible_lazy())
+		return;
 	preempt_schedule_common();
 }
 NOKPROBE_SYMBOL(preempt_schedule);
@@ -3647,6 +3766,9 @@ asmlinkage __visible void __sched notrac
 	if (likely(!preemptible()))
 		return;
 
+	if (!preemptible_lazy())
+		return;
+
 	do {
 		/*
 		 * Because the function tracer can trace preempt_count_sub()
@@ -4275,7 +4397,7 @@ change:
 			 * the entire root_domain to become SCHED_DEADLINE. We
 			 * will also fail if there's no bandwidth available.
 			 */
-			if (!cpumask_subset(span, &p->cpus_allowed) ||
+			if (!cpumask_subset(span, p->cpus_ptr) ||
 			    rq->rd->dl_bw.bw == 0) {
 				task_rq_unlock(rq, p, &rf);
 				return -EPERM;
@@ -4874,7 +4996,7 @@ long sched_getaffinity(pid_t pid, struct
 		goto out_unlock;
 
 	raw_spin_lock_irqsave(&p->pi_lock, flags);
-	cpumask_and(mask, &p->cpus_allowed, cpu_active_mask);
+	cpumask_and(mask, &p->cpus_mask, cpu_active_mask);
 	raw_spin_unlock_irqrestore(&p->pi_lock, flags);
 
 out_unlock:
@@ -5415,7 +5537,9 @@ void init_idle(struct task_struct *idle,
 
 	/* Set the preempt count _outside_ the spinlocks! */
 	init_idle_preempt_count(idle, cpu);
-
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+	task_thread_info(idle)->preempt_lazy_count = 0;
+#endif
 	/*
 	 * The idle tasks have their own, simple scheduling class:
 	 */
@@ -5454,7 +5578,7 @@ int task_can_attach(struct task_struct *
 	 * allowed nodes is unnecessary.  Thus, cpusets are not
 	 * applicable for such threads.  This prevents checking for
 	 * success of set_cpus_allowed_ptr() on all attached tasks
-	 * before cpus_allowed may be changed.
+	 * before cpus_mask may be changed.
 	 */
 	if (p->flags & PF_NO_SETAFFINITY) {
 		ret = -EINVAL;
@@ -5481,7 +5605,7 @@ int migrate_task_to(struct task_struct *
 	if (curr_cpu == target_cpu)
 		return 0;
 
-	if (!cpumask_test_cpu(target_cpu, &p->cpus_allowed))
+	if (!cpumask_test_cpu(target_cpu, p->cpus_ptr))
 		return -EINVAL;
 
 	/* TODO: This is not properly updating schedstats */
@@ -5520,6 +5644,8 @@ void sched_setnuma(struct task_struct *p
 #endif /* CONFIG_NUMA_BALANCING */
 
 #ifdef CONFIG_HOTPLUG_CPU
+static DEFINE_PER_CPU(struct mm_struct *, idle_last_mm);
+
 /*
  * Ensure that the idle task is using init_mm right before its CPU goes
  * offline.
@@ -5535,7 +5661,11 @@ void idle_task_exit(void)
 		current->active_mm = &init_mm;
 		finish_arch_post_lock_switch();
 	}
-	mmdrop(mm);
+	/*
+	 * Defer the cleanup to an alive cpu. On RT we can neither
+	 * call mmdrop() nor mmdrop_delayed() from here.
+	 */
+	per_cpu(idle_last_mm, smp_processor_id()) = mm;
 }
 
 /*
@@ -5619,7 +5749,7 @@ static void migrate_tasks(struct rq *dea
 		put_prev_task(rq, next);
 
 		/*
-		 * Rules for changing task_struct::cpus_allowed are holding
+		 * Rules for changing task_struct::cpus_mask are holding
 		 * both pi_lock and rq->lock, such that holding either
 		 * stabilizes the mask.
 		 *
@@ -5847,6 +5977,10 @@ int sched_cpu_dying(unsigned int cpu)
 	update_max_interval();
 	nohz_balance_exit_idle(rq);
 	hrtick_clear(rq);
+	if (per_cpu(idle_last_mm, cpu)) {
+		mmdrop_delayed(per_cpu(idle_last_mm, cpu));
+		per_cpu(idle_last_mm, cpu) = NULL;
+	}
 	return 0;
 }
 #endif
@@ -6081,7 +6215,7 @@ void __init sched_init(void)
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 static inline int preempt_count_equals(int preempt_offset)
 {
-	int nested = preempt_count() + rcu_preempt_depth();
+	int nested = preempt_count() + sched_rcu_preempt_depth();
 
 	return (nested == preempt_offset);
 }
@@ -7060,3 +7194,196 @@ const u32 sched_prio_to_wmult[40] = {
 };
 
 #undef CREATE_TRACE_POINTS
+
+#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+
+static inline void
+update_nr_migratory(struct task_struct *p, long delta)
+{
+	if (unlikely((p->sched_class == &rt_sched_class ||
+		      p->sched_class == &dl_sched_class) &&
+		      p->nr_cpus_allowed > 1)) {
+		if (p->sched_class == &rt_sched_class)
+			task_rq(p)->rt.rt_nr_migratory += delta;
+		else
+			task_rq(p)->dl.dl_nr_migratory += delta;
+	}
+}
+
+static inline void
+migrate_disable_update_cpus_allowed(struct task_struct *p)
+{
+	struct rq *rq;
+	struct rq_flags rf;
+
+	p->cpus_ptr = cpumask_of(smp_processor_id());
+
+	rq = task_rq_lock(p, &rf);
+	update_nr_migratory(p, -1);
+	p->nr_cpus_allowed = 1;
+	task_rq_unlock(rq, p, &rf);
+}
+
+static inline void
+migrate_enable_update_cpus_allowed(struct task_struct *p)
+{
+	struct rq *rq;
+	struct rq_flags rf;
+
+	p->cpus_ptr = &p->cpus_mask;
+
+	rq = task_rq_lock(p, &rf);
+	p->nr_cpus_allowed = cpumask_weight(&p->cpus_mask);
+	update_nr_migratory(p, 1);
+	task_rq_unlock(rq, p, &rf);
+}
+
+void migrate_disable(void)
+{
+	struct task_struct *p = current;
+
+	if (in_atomic() || irqs_disabled()) {
+#ifdef CONFIG_SCHED_DEBUG
+		p->migrate_disable_atomic++;
+#endif
+		return;
+	}
+#ifdef CONFIG_SCHED_DEBUG
+	if (unlikely(p->migrate_disable_atomic)) {
+		tracing_off();
+		WARN_ON_ONCE(1);
+	}
+#endif
+
+	if (p->migrate_disable) {
+		p->migrate_disable++;
+		return;
+	}
+
+	preempt_disable();
+	preempt_lazy_disable();
+	pin_current_cpu();
+
+	migrate_disable_update_cpus_allowed(p);
+	p->migrate_disable = 1;
+
+	preempt_enable();
+}
+EXPORT_SYMBOL(migrate_disable);
+
+void migrate_enable(void)
+{
+	struct task_struct *p = current;
+
+	if (in_atomic() || irqs_disabled()) {
+#ifdef CONFIG_SCHED_DEBUG
+		p->migrate_disable_atomic--;
+#endif
+		return;
+	}
+
+#ifdef CONFIG_SCHED_DEBUG
+	if (unlikely(p->migrate_disable_atomic)) {
+		tracing_off();
+		WARN_ON_ONCE(1);
+	}
+#endif
+
+	WARN_ON_ONCE(p->migrate_disable <= 0);
+	if (p->migrate_disable > 1) {
+		p->migrate_disable--;
+		return;
+	}
+
+	preempt_disable();
+
+	p->migrate_disable = 0;
+	migrate_enable_update_cpus_allowed(p);
+
+	if (p->migrate_disable_update) {
+		struct rq *rq;
+		struct rq_flags rf;
+
+		rq = task_rq_lock(p, &rf);
+		update_rq_clock(rq);
+
+		__do_set_cpus_allowed_tail(p, &p->cpus_mask);
+		task_rq_unlock(rq, p, &rf);
+
+		p->migrate_disable_update = 0;
+
+		WARN_ON(smp_processor_id() != task_cpu(p));
+		if (!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) {
+			const struct cpumask *cpu_valid_mask = cpu_active_mask;
+			struct migration_arg arg;
+			unsigned int dest_cpu;
+
+			if (p->flags & PF_KTHREAD) {
+				/*
+				 * Kernel threads are allowed on online && !active CPUs
+				 */
+				cpu_valid_mask = cpu_online_mask;
+			}
+			dest_cpu = cpumask_any_and(cpu_valid_mask, &p->cpus_mask);
+			arg.task = p;
+			arg.dest_cpu = dest_cpu;
+
+			unpin_current_cpu();
+			preempt_lazy_enable();
+			preempt_enable();
+			stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg);
+			tlb_migrate_finish(p->mm);
+
+			return;
+		}
+	}
+	unpin_current_cpu();
+	preempt_lazy_enable();
+	preempt_enable();
+}
+EXPORT_SYMBOL(migrate_enable);
+
+#elif !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+void migrate_disable(void)
+{
+#ifdef CONFIG_SCHED_DEBUG
+	struct task_struct *p = current;
+
+	if (in_atomic() || irqs_disabled()) {
+		p->migrate_disable_atomic++;
+		return;
+	}
+
+	if (unlikely(p->migrate_disable_atomic)) {
+		tracing_off();
+		WARN_ON_ONCE(1);
+	}
+
+	p->migrate_disable++;
+#endif
+	barrier();
+}
+EXPORT_SYMBOL(migrate_disable);
+
+void migrate_enable(void)
+{
+#ifdef CONFIG_SCHED_DEBUG
+	struct task_struct *p = current;
+
+	if (in_atomic() || irqs_disabled()) {
+		p->migrate_disable_atomic--;
+		return;
+	}
+
+	if (unlikely(p->migrate_disable_atomic)) {
+		tracing_off();
+		WARN_ON_ONCE(1);
+	}
+
+	WARN_ON_ONCE(p->migrate_disable <= 0);
+	p->migrate_disable--;
+#endif
+	barrier();
+}
+EXPORT_SYMBOL(migrate_enable);
+#endif
Index: linux-4.19.25-rt16/kernel/sched/cpudeadline.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/cpudeadline.c
+++ linux-4.19.25-rt16/kernel/sched/cpudeadline.c
@@ -124,14 +124,14 @@ int cpudl_find(struct cpudl *cp, struct
 	const struct sched_dl_entity *dl_se = &p->dl;
 
 	if (later_mask &&
-	    cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) {
+	    cpumask_and(later_mask, cp->free_cpus, p->cpus_ptr)) {
 		return 1;
 	} else {
 		int best_cpu = cpudl_maximum(cp);
 
 		WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
 
-		if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) &&
+		if (cpumask_test_cpu(best_cpu, p->cpus_ptr) &&
 		    dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
 			if (later_mask)
 				cpumask_set_cpu(best_cpu, later_mask);
Index: linux-4.19.25-rt16/kernel/sched/cpupri.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/cpupri.c
+++ linux-4.19.25-rt16/kernel/sched/cpupri.c
@@ -98,11 +98,11 @@ int cpupri_find(struct cpupri *cp, struc
 		if (skip)
 			continue;
 
-		if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
+		if (cpumask_any_and(p->cpus_ptr, vec->mask) >= nr_cpu_ids)
 			continue;
 
 		if (lowest_mask) {
-			cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
+			cpumask_and(lowest_mask, p->cpus_ptr, vec->mask);
 
 			/*
 			 * We have to ensure that we have at least one bit
Index: linux-4.19.25-rt16/kernel/sched/deadline.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/deadline.c
+++ linux-4.19.25-rt16/kernel/sched/deadline.c
@@ -539,7 +539,7 @@ static struct rq *dl_task_offline_migrat
 		 * If we cannot preempt any rq, fall back to pick any
 		 * online CPU:
 		 */
-		cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
+		cpu = cpumask_any_and(cpu_active_mask, p->cpus_ptr);
 		if (cpu >= nr_cpu_ids) {
 			/*
 			 * Failed to find any suitable CPU.
@@ -1054,7 +1054,7 @@ void init_dl_task_timer(struct sched_dl_
 {
 	struct hrtimer *timer = &dl_se->dl_timer;
 
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	timer->function = dl_task_timer;
 }
 
@@ -1824,7 +1824,7 @@ static void set_curr_task_dl(struct rq *
 static int pick_dl_task(struct rq *rq, struct task_struct *p, int cpu)
 {
 	if (!task_running(rq, p) &&
-	    cpumask_test_cpu(cpu, &p->cpus_allowed))
+	    cpumask_test_cpu(cpu, p->cpus_ptr))
 		return 1;
 	return 0;
 }
@@ -1974,7 +1974,7 @@ static struct rq *find_lock_later_rq(str
 		/* Retry if something changed. */
 		if (double_lock_balance(rq, later_rq)) {
 			if (unlikely(task_rq(task) != rq ||
-				     !cpumask_test_cpu(later_rq->cpu, &task->cpus_allowed) ||
+				     !cpumask_test_cpu(later_rq->cpu, task->cpus_ptr) ||
 				     task_running(rq, task) ||
 				     !dl_task(task) ||
 				     !task_on_rq_queued(task))) {
Index: linux-4.19.25-rt16/kernel/sched/debug.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/debug.c
+++ linux-4.19.25-rt16/kernel/sched/debug.c
@@ -982,6 +982,10 @@ void proc_sched_show_task(struct task_st
 		P(dl.runtime);
 		P(dl.deadline);
 	}
+#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT_BASE)
+	P(migrate_disable);
+#endif
+	P(nr_cpus_allowed);
 #undef PN_SCHEDSTAT
 #undef PN
 #undef __PN
Index: linux-4.19.25-rt16/kernel/sched/fair.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/fair.c
+++ linux-4.19.25-rt16/kernel/sched/fair.c
@@ -1630,7 +1630,7 @@ static void task_numa_compare(struct tas
 	 * be incurred if the tasks were swapped.
 	 */
 	/* Skip this swap candidate if cannot move to the source cpu */
-	if (!cpumask_test_cpu(env->src_cpu, &cur->cpus_allowed))
+	if (!cpumask_test_cpu(env->src_cpu, cur->cpus_ptr))
 		goto unlock;
 
 	/*
@@ -1727,7 +1727,7 @@ static void task_numa_find_cpu(struct ta
 
 	for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) {
 		/* Skip this CPU if the source task cannot migrate */
-		if (!cpumask_test_cpu(cpu, &env->p->cpus_allowed))
+		if (!cpumask_test_cpu(cpu, env->p->cpus_ptr))
 			continue;
 
 		env->dst_cpu = cpu;
@@ -4017,7 +4017,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq
 	ideal_runtime = sched_slice(cfs_rq, curr);
 	delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
 	if (delta_exec > ideal_runtime) {
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 		/*
 		 * The current task ran long enough, ensure it doesn't get
 		 * re-elected due to buddy favours.
@@ -4041,7 +4041,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq
 		return;
 
 	if (delta > ideal_runtime)
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 }
 
 static void
@@ -4183,7 +4183,7 @@ entity_tick(struct cfs_rq *cfs_rq, struc
 	 * validating it and just reschedule.
 	 */
 	if (queued) {
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 		return;
 	}
 	/*
@@ -4367,7 +4367,7 @@ static void __account_cfs_rq_runtime(str
 	 * hierarchy can be throttled
 	 */
 	if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 }
 
 static __always_inline
@@ -4553,7 +4553,7 @@ static u64 distribute_cfs_runtime(struct
 		struct rq *rq = rq_of(cfs_rq);
 		struct rq_flags rf;
 
-		rq_lock(rq, &rf);
+		rq_lock_irqsave(rq, &rf);
 		if (!cfs_rq_throttled(cfs_rq))
 			goto next;
 
@@ -4570,7 +4570,7 @@ static u64 distribute_cfs_runtime(struct
 			unthrottle_cfs_rq(cfs_rq);
 
 next:
-		rq_unlock(rq, &rf);
+		rq_unlock_irqrestore(rq, &rf);
 
 		if (!remaining)
 			break;
@@ -4586,7 +4586,7 @@ next:
  * period the timer is deactivated until scheduling resumes; cfs_b->idle is
  * used to track this state.
  */
-static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
+static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, unsigned long flags)
 {
 	u64 runtime, runtime_expires;
 	int throttled;
@@ -4628,11 +4628,11 @@ static int do_sched_cfs_period_timer(str
 	while (throttled && cfs_b->runtime > 0 && !cfs_b->distribute_running) {
 		runtime = cfs_b->runtime;
 		cfs_b->distribute_running = 1;
-		raw_spin_unlock(&cfs_b->lock);
+		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 		/* we can't nest cfs_b->lock while distributing bandwidth */
 		runtime = distribute_cfs_runtime(cfs_b, runtime,
 						 runtime_expires);
-		raw_spin_lock(&cfs_b->lock);
+		raw_spin_lock_irqsave(&cfs_b->lock, flags);
 
 		cfs_b->distribute_running = 0;
 		throttled = !list_empty(&cfs_b->throttled_cfs_rq);
@@ -4741,17 +4741,18 @@ static __always_inline void return_cfs_r
 static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
 {
 	u64 runtime = 0, slice = sched_cfs_bandwidth_slice();
+	unsigned long flags;
 	u64 expires;
 
 	/* confirm we're still not at a refresh boundary */
-	raw_spin_lock(&cfs_b->lock);
+	raw_spin_lock_irqsave(&cfs_b->lock, flags);
 	if (cfs_b->distribute_running) {
-		raw_spin_unlock(&cfs_b->lock);
+		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 		return;
 	}
 
 	if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) {
-		raw_spin_unlock(&cfs_b->lock);
+		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 		return;
 	}
 
@@ -4762,18 +4763,18 @@ static void do_sched_cfs_slack_timer(str
 	if (runtime)
 		cfs_b->distribute_running = 1;
 
-	raw_spin_unlock(&cfs_b->lock);
+	raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 
 	if (!runtime)
 		return;
 
 	runtime = distribute_cfs_runtime(cfs_b, runtime, expires);
 
-	raw_spin_lock(&cfs_b->lock);
+	raw_spin_lock_irqsave(&cfs_b->lock, flags);
 	if (expires == cfs_b->runtime_expires)
 		cfs_b->runtime -= min(runtime, cfs_b->runtime);
 	cfs_b->distribute_running = 0;
-	raw_spin_unlock(&cfs_b->lock);
+	raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 }
 
 /*
@@ -4853,11 +4854,12 @@ static enum hrtimer_restart sched_cfs_pe
 {
 	struct cfs_bandwidth *cfs_b =
 		container_of(timer, struct cfs_bandwidth, period_timer);
+	unsigned long flags;
 	int overrun;
 	int idle = 0;
 	int count = 0;
 
-	raw_spin_lock(&cfs_b->lock);
+	raw_spin_lock_irqsave(&cfs_b->lock, flags);
 	for (;;) {
 		overrun = hrtimer_forward_now(timer, cfs_b->period);
 		if (!overrun)
@@ -4885,11 +4887,11 @@ static enum hrtimer_restart sched_cfs_pe
 			count = 0;
 		}
 
-		idle = do_sched_cfs_period_timer(cfs_b, overrun);
+		idle = do_sched_cfs_period_timer(cfs_b, overrun, flags);
 	}
 	if (idle)
 		cfs_b->period_active = 0;
-	raw_spin_unlock(&cfs_b->lock);
+	raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 
 	return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
 }
@@ -5061,7 +5063,7 @@ static void hrtick_start_fair(struct rq
 
 		if (delta < 0) {
 			if (rq->curr == p)
-				resched_curr(rq);
+				resched_curr_lazy(rq);
 			return;
 		}
 		hrtick_start(rq, delta);
@@ -5735,7 +5737,7 @@ find_idlest_group(struct sched_domain *s
 
 		/* Skip over this group if it has no CPUs allowed */
 		if (!cpumask_intersects(sched_group_span(group),
-					&p->cpus_allowed))
+					p->cpus_ptr))
 			continue;
 
 		local_group = cpumask_test_cpu(this_cpu,
@@ -5867,7 +5869,7 @@ find_idlest_group_cpu(struct sched_group
 		return cpumask_first(sched_group_span(group));
 
 	/* Traverse only the allowed CPUs */
-	for_each_cpu_and(i, sched_group_span(group), &p->cpus_allowed) {
+	for_each_cpu_and(i, sched_group_span(group), p->cpus_ptr) {
 		if (available_idle_cpu(i)) {
 			struct rq *rq = cpu_rq(i);
 			struct cpuidle_state *idle = idle_get_state(rq);
@@ -5907,7 +5909,7 @@ static inline int find_idlest_cpu(struct
 {
 	int new_cpu = cpu;
 
-	if (!cpumask_intersects(sched_domain_span(sd), &p->cpus_allowed))
+	if (!cpumask_intersects(sched_domain_span(sd), p->cpus_ptr))
 		return prev_cpu;
 
 	/*
@@ -6024,7 +6026,7 @@ static int select_idle_core(struct task_
 	if (!test_idle_cores(target, false))
 		return -1;
 
-	cpumask_and(cpus, sched_domain_span(sd), &p->cpus_allowed);
+	cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
 
 	for_each_cpu_wrap(core, cpus, target) {
 		bool idle = true;
@@ -6058,7 +6060,7 @@ static int select_idle_smt(struct task_s
 		return -1;
 
 	for_each_cpu(cpu, cpu_smt_mask(target)) {
-		if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
+		if (!cpumask_test_cpu(cpu, p->cpus_ptr))
 			continue;
 		if (available_idle_cpu(cpu))
 			return cpu;
@@ -6121,7 +6123,7 @@ static int select_idle_cpu(struct task_s
 	for_each_cpu_wrap(cpu, sched_domain_span(sd), target) {
 		if (!--nr)
 			return -1;
-		if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
+		if (!cpumask_test_cpu(cpu, p->cpus_ptr))
 			continue;
 		if (available_idle_cpu(cpu))
 			break;
@@ -6158,7 +6160,7 @@ static int select_idle_sibling(struct ta
 	    recent_used_cpu != target &&
 	    cpus_share_cache(recent_used_cpu, target) &&
 	    available_idle_cpu(recent_used_cpu) &&
-	    cpumask_test_cpu(p->recent_used_cpu, &p->cpus_allowed)) {
+	    cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr)) {
 		/*
 		 * Replace recent_used_cpu with prev as it is a potential
 		 * candidate for the next wake:
@@ -6376,7 +6378,7 @@ select_task_rq_fair(struct task_struct *
 	if (sd_flag & SD_BALANCE_WAKE) {
 		record_wakee(p);
 		want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu)
-			      && cpumask_test_cpu(cpu, &p->cpus_allowed);
+			      && cpumask_test_cpu(cpu, p->cpus_ptr);
 	}
 
 	rcu_read_lock();
@@ -6637,7 +6639,7 @@ static void check_preempt_wakeup(struct
 	return;
 
 preempt:
-	resched_curr(rq);
+	resched_curr_lazy(rq);
 	/*
 	 * Only set the backward buddy when the current task is still
 	 * on the rq. This can happen when a wakeup gets interleaved
@@ -7115,14 +7117,14 @@ int can_migrate_task(struct task_struct
 	/*
 	 * We do not migrate tasks that are:
 	 * 1) throttled_lb_pair, or
-	 * 2) cannot be migrated to this CPU due to cpus_allowed, or
+	 * 2) cannot be migrated to this CPU due to cpus_ptr, or
 	 * 3) running (obviously), or
 	 * 4) are cache-hot on their current CPU.
 	 */
 	if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
 		return 0;
 
-	if (!cpumask_test_cpu(env->dst_cpu, &p->cpus_allowed)) {
+	if (!cpumask_test_cpu(env->dst_cpu, p->cpus_ptr)) {
 		int cpu;
 
 		schedstat_inc(p->se.statistics.nr_failed_migrations_affine);
@@ -7142,7 +7144,7 @@ int can_migrate_task(struct task_struct
 
 		/* Prevent to re-select dst_cpu via env's CPUs: */
 		for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) {
-			if (cpumask_test_cpu(cpu, &p->cpus_allowed)) {
+			if (cpumask_test_cpu(cpu, p->cpus_ptr)) {
 				env->flags |= LBF_DST_PINNED;
 				env->new_dst_cpu = cpu;
 				break;
@@ -7739,7 +7741,7 @@ check_cpu_capacity(struct rq *rq, struct
 
 /*
  * Group imbalance indicates (and tries to solve) the problem where balancing
- * groups is inadequate due to ->cpus_allowed constraints.
+ * groups is inadequate due to ->cpus_ptr constraints.
  *
  * Imagine a situation of two groups of 4 CPUs each and 4 tasks each with a
  * cpumask covering 1 CPU of the first group and 3 CPUs of the second group.
@@ -8354,7 +8356,7 @@ static struct sched_group *find_busiest_
 	/*
 	 * If the busiest group is imbalanced the below checks don't
 	 * work because they assume all things are equal, which typically
-	 * isn't true due to cpus_allowed constraints and the like.
+	 * isn't true due to cpus_ptr constraints and the like.
 	 */
 	if (busiest->group_type == group_imbalanced)
 		goto force_balance;
@@ -8750,7 +8752,7 @@ more_balance:
 			 * if the curr task on busiest CPU can't be
 			 * moved to this_cpu:
 			 */
-			if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) {
+			if (!cpumask_test_cpu(this_cpu, busiest->curr->cpus_ptr)) {
 				raw_spin_unlock_irqrestore(&busiest->lock,
 							    flags);
 				env.flags |= LBF_ALL_PINNED;
@@ -9724,7 +9726,7 @@ static void task_fork_fair(struct task_s
 		 * 'current' within the tree based on its new key value.
 		 */
 		swap(curr->vruntime, se->vruntime);
-		resched_curr(rq);
+		resched_curr_lazy(rq);
 	}
 
 	se->vruntime -= cfs_rq->min_vruntime;
@@ -9748,7 +9750,7 @@ prio_changed_fair(struct rq *rq, struct
 	 */
 	if (rq->curr == p) {
 		if (p->prio > oldprio)
-			resched_curr(rq);
+			resched_curr_lazy(rq);
 	} else
 		check_preempt_curr(rq, p, 0);
 }
Index: linux-4.19.25-rt16/kernel/sched/features.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/features.h
+++ linux-4.19.25-rt16/kernel/sched/features.h
@@ -46,11 +46,19 @@ SCHED_FEAT(LB_BIAS, true)
  */
 SCHED_FEAT(NONTASK_CAPACITY, true)
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+SCHED_FEAT(TTWU_QUEUE, false)
+# ifdef CONFIG_PREEMPT_LAZY
+SCHED_FEAT(PREEMPT_LAZY, true)
+# endif
+#else
+
 /*
  * Queue remote wakeups on the target CPU and process them
  * using the scheduler IPI. Reduces rq->lock contention/bounces.
  */
 SCHED_FEAT(TTWU_QUEUE, true)
+#endif
 
 /*
  * When doing wakeups, attempt to limit superfluous scans of the LLC domain.
Index: linux-4.19.25-rt16/kernel/sched/rt.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/rt.c
+++ linux-4.19.25-rt16/kernel/sched/rt.c
@@ -45,8 +45,8 @@ void init_rt_bandwidth(struct rt_bandwid
 
 	raw_spin_lock_init(&rt_b->rt_runtime_lock);
 
-	hrtimer_init(&rt_b->rt_period_timer,
-			CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_REL_HARD);
 	rt_b->rt_period_timer.function = sched_rt_period_timer;
 }
 
@@ -1611,7 +1611,7 @@ static void put_prev_task_rt(struct rq *
 static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 {
 	if (!task_running(rq, p) &&
-	    cpumask_test_cpu(cpu, &p->cpus_allowed))
+	    cpumask_test_cpu(cpu, p->cpus_ptr))
 		return 1;
 
 	return 0;
@@ -1748,7 +1748,7 @@ static struct rq *find_lock_lowest_rq(st
 			 * Also make sure that it wasn't scheduled on its rq.
 			 */
 			if (unlikely(task_rq(task) != rq ||
-				     !cpumask_test_cpu(lowest_rq->cpu, &task->cpus_allowed) ||
+				     !cpumask_test_cpu(lowest_rq->cpu, task->cpus_ptr) ||
 				     task_running(rq, task) ||
 				     !rt_task(task) ||
 				     !task_on_rq_queued(task))) {
Index: linux-4.19.25-rt16/kernel/sched/sched.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/sched.h
+++ linux-4.19.25-rt16/kernel/sched/sched.h
@@ -1443,6 +1443,7 @@ static inline int task_on_rq_migrating(s
 #define WF_SYNC			0x01		/* Waker goes to sleep after wakeup */
 #define WF_FORK			0x02		/* Child wakeup after fork */
 #define WF_MIGRATED		0x4		/* Internal use, task got migrated */
+#define WF_LOCK_SLEEPER		0x08		/* wakeup spinlock "sleeper" */
 
 /*
  * To aid in avoiding the subversion of "niceness" due to uneven distribution
@@ -1637,6 +1638,15 @@ extern void reweight_task(struct task_st
 extern void resched_curr(struct rq *rq);
 extern void resched_cpu(int cpu);
 
+#ifdef CONFIG_PREEMPT_LAZY
+extern void resched_curr_lazy(struct rq *rq);
+#else
+static inline void resched_curr_lazy(struct rq *rq)
+{
+	resched_curr(rq);
+}
+#endif
+
 extern struct rt_bandwidth def_rt_bandwidth;
 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
 
Index: linux-4.19.25-rt16/kernel/sched/swait.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/swait.c
+++ linux-4.19.25-rt16/kernel/sched/swait.c
@@ -32,6 +32,25 @@ void swake_up_locked(struct swait_queue_
 }
 EXPORT_SYMBOL(swake_up_locked);
 
+void swake_up_all_locked(struct swait_queue_head *q)
+{
+	struct swait_queue *curr;
+	int wakes = 0;
+
+	while (!list_empty(&q->task_list)) {
+
+		curr = list_first_entry(&q->task_list, typeof(*curr),
+					task_list);
+		wake_up_process(curr->task);
+		list_del_init(&curr->task_list);
+		wakes++;
+	}
+	if (pm_in_action)
+		return;
+	WARN(wakes > 2, "complete_all() with %d waiters\n", wakes);
+}
+EXPORT_SYMBOL(swake_up_all_locked);
+
 void swake_up_one(struct swait_queue_head *q)
 {
 	unsigned long flags;
@@ -51,6 +70,7 @@ void swake_up_all(struct swait_queue_hea
 	struct swait_queue *curr;
 	LIST_HEAD(tmp);
 
+	WARN_ON(irqs_disabled());
 	raw_spin_lock_irq(&q->lock);
 	list_splice_init(&q->task_list, &tmp);
 	while (!list_empty(&tmp)) {
@@ -69,7 +89,7 @@ void swake_up_all(struct swait_queue_hea
 }
 EXPORT_SYMBOL(swake_up_all);
 
-static void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
+void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
 {
 	wait->task = current;
 	if (list_empty(&wait->task_list))
Index: linux-4.19.25-rt16/kernel/sched/swork.c
===================================================================
--- /dev/null
+++ linux-4.19.25-rt16/kernel/sched/swork.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2014 BMW Car IT GmbH, Daniel Wagner daniel.wagner@bmw-carit.de
+ *
+ * Provides a framework for enqueuing callbacks from irq context
+ * PREEMPT_RT_FULL safe. The callbacks are executed in kthread context.
+ */
+
+#include <linux/swait.h>
+#include <linux/swork.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/export.h>
+
+#define SWORK_EVENT_PENDING     1
+
+static DEFINE_MUTEX(worker_mutex);
+static struct sworker *glob_worker;
+
+struct sworker {
+	struct list_head events;
+	struct swait_queue_head wq;
+
+	raw_spinlock_t lock;
+
+	struct task_struct *task;
+	int refs;
+};
+
+static bool swork_readable(struct sworker *worker)
+{
+	bool r;
+
+	if (kthread_should_stop())
+		return true;
+
+	raw_spin_lock_irq(&worker->lock);
+	r = !list_empty(&worker->events);
+	raw_spin_unlock_irq(&worker->lock);
+
+	return r;
+}
+
+static int swork_kthread(void *arg)
+{
+	struct sworker *worker = arg;
+
+	for (;;) {
+		swait_event_interruptible_exclusive(worker->wq,
+						    swork_readable(worker));
+		if (kthread_should_stop())
+			break;
+
+		raw_spin_lock_irq(&worker->lock);
+		while (!list_empty(&worker->events)) {
+			struct swork_event *sev;
+
+			sev = list_first_entry(&worker->events,
+					struct swork_event, item);
+			list_del(&sev->item);
+			raw_spin_unlock_irq(&worker->lock);
+
+			WARN_ON_ONCE(!test_and_clear_bit(SWORK_EVENT_PENDING,
+							 &sev->flags));
+			sev->func(sev);
+			raw_spin_lock_irq(&worker->lock);
+		}
+		raw_spin_unlock_irq(&worker->lock);
+	}
+	return 0;
+}
+
+static struct sworker *swork_create(void)
+{
+	struct sworker *worker;
+
+	worker = kzalloc(sizeof(*worker), GFP_KERNEL);
+	if (!worker)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&worker->events);
+	raw_spin_lock_init(&worker->lock);
+	init_swait_queue_head(&worker->wq);
+
+	worker->task = kthread_run(swork_kthread, worker, "kswork");
+	if (IS_ERR(worker->task)) {
+		kfree(worker);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return worker;
+}
+
+static void swork_destroy(struct sworker *worker)
+{
+	kthread_stop(worker->task);
+
+	WARN_ON(!list_empty(&worker->events));
+	kfree(worker);
+}
+
+/**
+ * swork_queue - queue swork
+ *
+ * Returns %false if @work was already on a queue, %true otherwise.
+ *
+ * The work is queued and processed on a random CPU
+ */
+bool swork_queue(struct swork_event *sev)
+{
+	unsigned long flags;
+
+	if (test_and_set_bit(SWORK_EVENT_PENDING, &sev->flags))
+		return false;
+
+	raw_spin_lock_irqsave(&glob_worker->lock, flags);
+	list_add_tail(&sev->item, &glob_worker->events);
+	raw_spin_unlock_irqrestore(&glob_worker->lock, flags);
+
+	swake_up_one(&glob_worker->wq);
+	return true;
+}
+EXPORT_SYMBOL_GPL(swork_queue);
+
+/**
+ * swork_get - get an instance of the sworker
+ *
+ * Returns an negative error code if the initialization if the worker did not
+ * work, %0 otherwise.
+ *
+ */
+int swork_get(void)
+{
+	struct sworker *worker;
+
+	mutex_lock(&worker_mutex);
+	if (!glob_worker) {
+		worker = swork_create();
+		if (IS_ERR(worker)) {
+			mutex_unlock(&worker_mutex);
+			return -ENOMEM;
+		}
+
+		glob_worker = worker;
+	}
+
+	glob_worker->refs++;
+	mutex_unlock(&worker_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(swork_get);
+
+/**
+ * swork_put - puts an instance of the sworker
+ *
+ * Will destroy the sworker thread. This function must not be called until all
+ * queued events have been completed.
+ */
+void swork_put(void)
+{
+	mutex_lock(&worker_mutex);
+
+	glob_worker->refs--;
+	if (glob_worker->refs > 0)
+		goto out;
+
+	swork_destroy(glob_worker);
+	glob_worker = NULL;
+out:
+	mutex_unlock(&worker_mutex);
+}
+EXPORT_SYMBOL_GPL(swork_put);
Index: linux-4.19.25-rt16/kernel/sched/topology.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/sched/topology.c
+++ linux-4.19.25-rt16/kernel/sched/topology.c
@@ -279,6 +279,7 @@ static int init_rootdomain(struct root_d
 	rd->rto_cpu = -1;
 	raw_spin_lock_init(&rd->rto_lock);
 	init_irq_work(&rd->rto_push_work, rto_push_irq_work_func);
+	rd->rto_push_work.flags |= IRQ_WORK_HARD_IRQ;
 #endif
 
 	init_dl_bw(&rd->dl_bw);
Index: linux-4.19.25-rt16/kernel/signal.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/signal.c
+++ linux-4.19.25-rt16/kernel/signal.c
@@ -19,6 +19,7 @@
 #include <linux/sched/task.h>
 #include <linux/sched/task_stack.h>
 #include <linux/sched/cputime.h>
+#include <linux/sched/rt.h>
 #include <linux/fs.h>
 #include <linux/tty.h>
 #include <linux/binfmts.h>
@@ -388,13 +389,30 @@ void task_join_group_stop(struct task_st
 	}
 }
 
+static inline struct sigqueue *get_task_cache(struct task_struct *t)
+{
+	struct sigqueue *q = t->sigqueue_cache;
+
+	if (cmpxchg(&t->sigqueue_cache, q, NULL) != q)
+		return NULL;
+	return q;
+}
+
+static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
+{
+	if (cmpxchg(&t->sigqueue_cache, NULL, q) == NULL)
+		return 0;
+	return 1;
+}
+
 /*
  * allocate a new signal queue record
  * - this may be called without locks if and only if t == current, otherwise an
  *   appropriate lock must be held to stop the target task from exiting
  */
 static struct sigqueue *
-__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit)
+__sigqueue_do_alloc(int sig, struct task_struct *t, gfp_t flags,
+		    int override_rlimit, int fromslab)
 {
 	struct sigqueue *q = NULL;
 	struct user_struct *user;
@@ -411,7 +429,10 @@ __sigqueue_alloc(int sig, struct task_st
 	if (override_rlimit ||
 	    atomic_read(&user->sigpending) <=
 			task_rlimit(t, RLIMIT_SIGPENDING)) {
-		q = kmem_cache_alloc(sigqueue_cachep, flags);
+		if (!fromslab)
+			q = get_task_cache(t);
+		if (!q)
+			q = kmem_cache_alloc(sigqueue_cachep, flags);
 	} else {
 		print_dropped_signal(sig);
 	}
@@ -428,6 +449,13 @@ __sigqueue_alloc(int sig, struct task_st
 	return q;
 }
 
+static struct sigqueue *
+__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags,
+		 int override_rlimit)
+{
+	return __sigqueue_do_alloc(sig, t, flags, override_rlimit, 0);
+}
+
 static void __sigqueue_free(struct sigqueue *q)
 {
 	if (q->flags & SIGQUEUE_PREALLOC)
@@ -437,6 +465,21 @@ static void __sigqueue_free(struct sigqu
 	kmem_cache_free(sigqueue_cachep, q);
 }
 
+static void sigqueue_free_current(struct sigqueue *q)
+{
+	struct user_struct *up;
+
+	if (q->flags & SIGQUEUE_PREALLOC)
+		return;
+
+	up = q->user;
+	if (rt_prio(current->normal_prio) && !put_task_cache(current, q)) {
+		atomic_dec(&up->sigpending);
+		free_uid(up);
+	} else
+		  __sigqueue_free(q);
+}
+
 void flush_sigqueue(struct sigpending *queue)
 {
 	struct sigqueue *q;
@@ -450,6 +493,21 @@ void flush_sigqueue(struct sigpending *q
 }
 
 /*
+ * Called from __exit_signal. Flush tsk->pending and
+ * tsk->sigqueue_cache
+ */
+void flush_task_sigqueue(struct task_struct *tsk)
+{
+	struct sigqueue *q;
+
+	flush_sigqueue(&tsk->pending);
+
+	q = get_task_cache(tsk);
+	if (q)
+		kmem_cache_free(sigqueue_cachep, q);
+}
+
+/*
  * Flush all pending signals for this kthread.
  */
 void flush_signals(struct task_struct *t)
@@ -572,7 +630,7 @@ still_pending:
 			(info->si_code == SI_TIMER) &&
 			(info->si_sys_private);
 
-		__sigqueue_free(first);
+		sigqueue_free_current(first);
 	} else {
 		/*
 		 * Ok, it wasn't in the queue.  This must be
@@ -609,6 +667,8 @@ int dequeue_signal(struct task_struct *t
 	bool resched_timer = false;
 	int signr;
 
+	WARN_ON_ONCE(tsk != current);
+
 	/* We only dequeue private signals from ourselves, we don't let
 	 * signalfd steal them
 	 */
@@ -1268,8 +1328,8 @@ int do_send_sig_info(int sig, struct sig
  * We don't want to have recursive SIGSEGV's etc, for example,
  * that is why we also clear SIGNAL_UNKILLABLE.
  */
-int
-force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+static int
+do_force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 {
 	unsigned long int flags;
 	int ret, blocked, ignored;
@@ -1298,6 +1358,39 @@ force_sig_info(int sig, struct siginfo *
 	return ret;
 }
 
+int force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+{
+/*
+ * On some archs, PREEMPT_RT has to delay sending a signal from a trap
+ * since it can not enable preemption, and the signal code's spin_locks
+ * turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME which will
+ * send the signal on exit of the trap.
+ */
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+	if (in_atomic()) {
+		if (WARN_ON_ONCE(t != current))
+			return 0;
+		if (WARN_ON_ONCE(t->forced_info.si_signo))
+			return 0;
+
+		if (is_si_special(info)) {
+			WARN_ON_ONCE(info != SEND_SIG_PRIV);
+			t->forced_info.si_signo = sig;
+			t->forced_info.si_errno = 0;
+			t->forced_info.si_code = SI_KERNEL;
+			t->forced_info.si_pid = 0;
+			t->forced_info.si_uid = 0;
+		} else {
+			t->forced_info = *info;
+		}
+
+		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+		return 0;
+	}
+#endif
+	return do_force_sig_info(sig, info, t);
+}
+
 /*
  * Nuke all other threads in the group.
  */
@@ -1714,7 +1807,8 @@ EXPORT_SYMBOL(kill_pid);
  */
 struct sigqueue *sigqueue_alloc(void)
 {
-	struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0);
+	/* Preallocated sigqueue objects always from the slabcache ! */
+	struct sigqueue *q = __sigqueue_do_alloc(-1, current, GFP_KERNEL, 0, 1);
 
 	if (q)
 		q->flags |= SIGQUEUE_PREALLOC;
@@ -2094,15 +2188,7 @@ static void ptrace_stop(int exit_code, i
 		if (gstop_done && ptrace_reparented(current))
 			do_notify_parent_cldstop(current, false, why);
 
-		/*
-		 * Don't want to allow preemption here, because
-		 * sys_ptrace() needs this task to be inactive.
-		 *
-		 * XXX: implement read_unlock_no_resched().
-		 */
-		preempt_disable();
 		read_unlock(&tasklist_lock);
-		preempt_enable_no_resched();
 		freezable_schedule();
 	} else {
 		/*
Index: linux-4.19.25-rt16/kernel/softirq.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/softirq.c
+++ linux-4.19.25-rt16/kernel/softirq.c
@@ -21,11 +21,14 @@
 #include <linux/freezer.h>
 #include <linux/kthread.h>
 #include <linux/rcupdate.h>
+#include <linux/delay.h>
 #include <linux/ftrace.h>
 #include <linux/smp.h>
 #include <linux/smpboot.h>
 #include <linux/tick.h>
+#include <linux/locallock.h>
 #include <linux/irq.h>
+#include <linux/sched/types.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/irq.h>
@@ -56,12 +59,136 @@ EXPORT_PER_CPU_SYMBOL(irq_stat);
 static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp;
 
 DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
+#ifdef CONFIG_PREEMPT_RT_FULL
+#define TIMER_SOFTIRQS ((1 << TIMER_SOFTIRQ) | (1 << HRTIMER_SOFTIRQ))
+DEFINE_PER_CPU(struct task_struct *, ktimer_softirqd);
+#endif
 
 const char * const softirq_to_name[NR_SOFTIRQS] = {
 	"HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "IRQ_POLL",
 	"TASKLET", "SCHED", "HRTIMER", "RCU"
 };
 
+#ifdef CONFIG_NO_HZ_COMMON
+# ifdef CONFIG_PREEMPT_RT_FULL
+
+struct softirq_runner {
+	struct task_struct *runner[NR_SOFTIRQS];
+};
+
+static DEFINE_PER_CPU(struct softirq_runner, softirq_runners);
+
+static inline void softirq_set_runner(unsigned int sirq)
+{
+	struct softirq_runner *sr = this_cpu_ptr(&softirq_runners);
+
+	sr->runner[sirq] = current;
+}
+
+static inline void softirq_clr_runner(unsigned int sirq)
+{
+	struct softirq_runner *sr = this_cpu_ptr(&softirq_runners);
+
+	sr->runner[sirq] = NULL;
+}
+
+static bool softirq_check_runner_tsk(struct task_struct *tsk,
+				     unsigned int *pending)
+{
+	bool ret = false;
+
+	if (!tsk)
+		return ret;
+
+	/*
+	 * The wakeup code in rtmutex.c wakes up the task
+	 * _before_ it sets pi_blocked_on to NULL under
+	 * tsk->pi_lock. So we need to check for both: state
+	 * and pi_blocked_on.
+	 * The test against UNINTERRUPTIBLE + ->sleeping_lock is in case the
+	 * task does cpu_chill().
+	 */
+	raw_spin_lock(&tsk->pi_lock);
+	if (tsk->pi_blocked_on || tsk->state == TASK_RUNNING ||
+	    (tsk->state == TASK_UNINTERRUPTIBLE && tsk->sleeping_lock)) {
+		/* Clear all bits pending in that task */
+		*pending &= ~(tsk->softirqs_raised);
+		ret = true;
+	}
+	raw_spin_unlock(&tsk->pi_lock);
+
+	return ret;
+}
+
+/*
+ * On preempt-rt a softirq running context might be blocked on a
+ * lock. There might be no other runnable task on this CPU because the
+ * lock owner runs on some other CPU. So we have to go into idle with
+ * the pending bit set. Therefor we need to check this otherwise we
+ * warn about false positives which confuses users and defeats the
+ * whole purpose of this test.
+ *
+ * This code is called with interrupts disabled.
+ */
+void softirq_check_pending_idle(void)
+{
+	struct task_struct *tsk;
+	static int rate_limit;
+	struct softirq_runner *sr = this_cpu_ptr(&softirq_runners);
+	u32 warnpending;
+	int i;
+
+	if (rate_limit >= 10)
+		return;
+
+	warnpending = local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK;
+	if (!warnpending)
+		return;
+	for (i = 0; i < NR_SOFTIRQS; i++) {
+		tsk = sr->runner[i];
+
+		if (softirq_check_runner_tsk(tsk, &warnpending))
+			warnpending &= ~(1 << i);
+	}
+
+	if (warnpending) {
+		tsk = __this_cpu_read(ksoftirqd);
+		softirq_check_runner_tsk(tsk, &warnpending);
+	}
+
+	if (warnpending) {
+		tsk = __this_cpu_read(ktimer_softirqd);
+		softirq_check_runner_tsk(tsk, &warnpending);
+	}
+
+	if (warnpending) {
+		printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+		       warnpending);
+		rate_limit++;
+	}
+}
+# else
+/*
+ * On !PREEMPT_RT we just printk rate limited:
+ */
+void softirq_check_pending_idle(void)
+{
+	static int rate_limit;
+
+	if (rate_limit < 10 &&
+			(local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
+		printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+		       local_softirq_pending());
+		rate_limit++;
+	}
+}
+# endif
+
+#else /* !CONFIG_NO_HZ_COMMON */
+static inline void softirq_set_runner(unsigned int sirq) { }
+static inline void softirq_clr_runner(unsigned int sirq) { }
+#endif
+
 /*
  * we cannot loop indefinitely here to avoid userspace starvation,
  * but we also don't want to introduce a worst case 1/HZ latency
@@ -77,6 +204,38 @@ static void wakeup_softirqd(void)
 		wake_up_process(tsk);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void wakeup_timer_softirqd(void)
+{
+	/* Interrupts are disabled: no need to stop preemption */
+	struct task_struct *tsk = __this_cpu_read(ktimer_softirqd);
+
+	if (tsk && tsk->state != TASK_RUNNING)
+		wake_up_process(tsk);
+}
+#endif
+
+static void handle_softirq(unsigned int vec_nr)
+{
+	struct softirq_action *h = softirq_vec + vec_nr;
+	int prev_count;
+
+	prev_count = preempt_count();
+
+	kstat_incr_softirqs_this_cpu(vec_nr);
+
+	trace_softirq_entry(vec_nr);
+	h->action(h);
+	trace_softirq_exit(vec_nr);
+	if (unlikely(prev_count != preempt_count())) {
+		pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n",
+		       vec_nr, softirq_to_name[vec_nr], h->action,
+		       prev_count, preempt_count());
+		preempt_count_set(prev_count);
+	}
+}
+
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * If ksoftirqd is scheduled, we do not want to process pending softirqs
  * right now. Let ksoftirqd handle this at its own rate, to get fairness,
@@ -92,6 +251,47 @@ static bool ksoftirqd_running(unsigned l
 	return tsk && (tsk->state == TASK_RUNNING);
 }
 
+static inline int ksoftirqd_softirq_pending(void)
+{
+	return local_softirq_pending();
+}
+
+static void handle_pending_softirqs(u32 pending)
+{
+	struct softirq_action *h = softirq_vec;
+	int softirq_bit;
+
+	local_irq_enable();
+
+	h = softirq_vec;
+
+	while ((softirq_bit = ffs(pending))) {
+		unsigned int vec_nr;
+
+		h += softirq_bit - 1;
+		vec_nr = h - softirq_vec;
+		handle_softirq(vec_nr);
+
+		h++;
+		pending >>= softirq_bit;
+	}
+
+	rcu_bh_qs();
+	local_irq_disable();
+}
+
+static void run_ksoftirqd(unsigned int cpu)
+{
+	local_irq_disable();
+	if (ksoftirqd_softirq_pending()) {
+		__do_softirq();
+		local_irq_enable();
+		cond_resched();
+		return;
+	}
+	local_irq_enable();
+}
+
 /*
  * preempt_count and SOFTIRQ_OFFSET usage:
  * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
@@ -251,10 +451,8 @@ asmlinkage __visible void __softirq_entr
 	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
 	unsigned long old_flags = current->flags;
 	int max_restart = MAX_SOFTIRQ_RESTART;
-	struct softirq_action *h;
 	bool in_hardirq;
 	__u32 pending;
-	int softirq_bit;
 
 	/*
 	 * Mask out PF_MEMALLOC s current task context is borrowed for the
@@ -273,36 +471,7 @@ restart:
 	/* Reset the pending bitmask before enabling irqs */
 	set_softirq_pending(0);
 
-	local_irq_enable();
-
-	h = softirq_vec;
-
-	while ((softirq_bit = ffs(pending))) {
-		unsigned int vec_nr;
-		int prev_count;
-
-		h += softirq_bit - 1;
-
-		vec_nr = h - softirq_vec;
-		prev_count = preempt_count();
-
-		kstat_incr_softirqs_this_cpu(vec_nr);
-
-		trace_softirq_entry(vec_nr);
-		h->action(h);
-		trace_softirq_exit(vec_nr);
-		if (unlikely(prev_count != preempt_count())) {
-			pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n",
-			       vec_nr, softirq_to_name[vec_nr], h->action,
-			       prev_count, preempt_count());
-			preempt_count_set(prev_count);
-		}
-		h++;
-		pending >>= softirq_bit;
-	}
-
-	rcu_bh_qs();
-	local_irq_disable();
+	handle_pending_softirqs(pending);
 
 	pending = local_softirq_pending();
 	if (pending) {
@@ -339,6 +508,309 @@ asmlinkage __visible void do_softirq(voi
 }
 
 /*
+ * This function must run with irqs disabled!
+ */
+void raise_softirq_irqoff(unsigned int nr)
+{
+	__raise_softirq_irqoff(nr);
+
+	/*
+	 * If we're in an interrupt or softirq, we're done
+	 * (this also catches softirq-disabled code). We will
+	 * actually run the softirq once we return from
+	 * the irq or softirq.
+	 *
+	 * Otherwise we wake up ksoftirqd to make sure we
+	 * schedule the softirq soon.
+	 */
+	if (!in_interrupt())
+		wakeup_softirqd();
+}
+
+void __raise_softirq_irqoff(unsigned int nr)
+{
+	trace_softirq_raise(nr);
+	or_softirq_pending(1UL << nr);
+}
+
+static inline void local_bh_disable_nort(void) { local_bh_disable(); }
+static inline void _local_bh_enable_nort(void) { _local_bh_enable(); }
+static void ksoftirqd_set_sched_params(unsigned int cpu) { }
+
+#else /* !PREEMPT_RT_FULL */
+
+/*
+ * On RT we serialize softirq execution with a cpu local lock per softirq
+ */
+static DEFINE_PER_CPU(struct local_irq_lock [NR_SOFTIRQS], local_softirq_locks);
+
+void __init softirq_early_init(void)
+{
+	int i;
+
+	for (i = 0; i < NR_SOFTIRQS; i++)
+		local_irq_lock_init(local_softirq_locks[i]);
+}
+
+static void lock_softirq(int which)
+{
+	local_lock(local_softirq_locks[which]);
+}
+
+static void unlock_softirq(int which)
+{
+	local_unlock(local_softirq_locks[which]);
+}
+
+static void do_single_softirq(int which)
+{
+	unsigned long old_flags = current->flags;
+
+	current->flags &= ~PF_MEMALLOC;
+	vtime_account_irq_enter(current);
+	current->flags |= PF_IN_SOFTIRQ;
+	lockdep_softirq_enter();
+	local_irq_enable();
+	handle_softirq(which);
+	local_irq_disable();
+	lockdep_softirq_exit();
+	current->flags &= ~PF_IN_SOFTIRQ;
+	vtime_account_irq_enter(current);
+	current_restore_flags(old_flags, PF_MEMALLOC);
+}
+
+/*
+ * Called with interrupts disabled. Process softirqs which were raised
+ * in current context (or on behalf of ksoftirqd).
+ */
+static void do_current_softirqs(void)
+{
+	while (current->softirqs_raised) {
+		int i = __ffs(current->softirqs_raised);
+		unsigned int pending, mask = (1U << i);
+
+		current->softirqs_raised &= ~mask;
+		local_irq_enable();
+
+		/*
+		 * If the lock is contended, we boost the owner to
+		 * process the softirq or leave the critical section
+		 * now.
+		 */
+		lock_softirq(i);
+		local_irq_disable();
+		softirq_set_runner(i);
+		/*
+		 * Check with the local_softirq_pending() bits,
+		 * whether we need to process this still or if someone
+		 * else took care of it.
+		 */
+		pending = local_softirq_pending();
+		if (pending & mask) {
+			set_softirq_pending(pending & ~mask);
+			do_single_softirq(i);
+		}
+		softirq_clr_runner(i);
+		WARN_ON(current->softirq_nestcnt != 1);
+		local_irq_enable();
+		unlock_softirq(i);
+		local_irq_disable();
+	}
+}
+
+void __local_bh_disable(void)
+{
+	if (++current->softirq_nestcnt == 1)
+		migrate_disable();
+}
+EXPORT_SYMBOL(__local_bh_disable);
+
+void __local_bh_enable(void)
+{
+	if (WARN_ON(current->softirq_nestcnt == 0))
+		return;
+
+	local_irq_disable();
+	if (current->softirq_nestcnt == 1 && current->softirqs_raised)
+		do_current_softirqs();
+	local_irq_enable();
+
+	if (--current->softirq_nestcnt == 0)
+		migrate_enable();
+}
+EXPORT_SYMBOL(__local_bh_enable);
+
+void _local_bh_enable(void)
+{
+	if (WARN_ON(current->softirq_nestcnt == 0))
+		return;
+	if (--current->softirq_nestcnt == 0)
+		migrate_enable();
+}
+EXPORT_SYMBOL(_local_bh_enable);
+
+int in_serving_softirq(void)
+{
+	return current->flags & PF_IN_SOFTIRQ;
+}
+EXPORT_SYMBOL(in_serving_softirq);
+
+/* Called with preemption disabled */
+static void run_ksoftirqd(unsigned int cpu)
+{
+	local_irq_disable();
+	current->softirq_nestcnt++;
+
+	do_current_softirqs();
+	current->softirq_nestcnt--;
+	local_irq_enable();
+	cond_resched();
+}
+
+/*
+ * Called from netif_rx_ni(). Preemption enabled, but migration
+ * disabled. So the cpu can't go away under us.
+ */
+void thread_do_softirq(void)
+{
+	if (!in_serving_softirq() && current->softirqs_raised) {
+		current->softirq_nestcnt++;
+		do_current_softirqs();
+		current->softirq_nestcnt--;
+	}
+}
+
+static void do_raise_softirq_irqoff(unsigned int nr)
+{
+	unsigned int mask;
+
+	mask = 1UL << nr;
+
+	trace_softirq_raise(nr);
+	or_softirq_pending(mask);
+
+	/*
+	 * If we are not in a hard interrupt and inside a bh disabled
+	 * region, we simply raise the flag on current. local_bh_enable()
+	 * will make sure that the softirq is executed. Otherwise we
+	 * delegate it to ksoftirqd.
+	 */
+	if (!in_irq() && current->softirq_nestcnt)
+		current->softirqs_raised |= mask;
+	else if (!__this_cpu_read(ksoftirqd) || !__this_cpu_read(ktimer_softirqd))
+		return;
+
+	if (mask & TIMER_SOFTIRQS)
+		__this_cpu_read(ktimer_softirqd)->softirqs_raised |= mask;
+	else
+		__this_cpu_read(ksoftirqd)->softirqs_raised |= mask;
+}
+
+static void wakeup_proper_softirq(unsigned int nr)
+{
+	if ((1UL << nr) & TIMER_SOFTIRQS)
+		wakeup_timer_softirqd();
+	else
+		wakeup_softirqd();
+}
+
+void __raise_softirq_irqoff(unsigned int nr)
+{
+	do_raise_softirq_irqoff(nr);
+	if (!in_irq() && !current->softirq_nestcnt)
+		wakeup_proper_softirq(nr);
+}
+
+/*
+ * Same as __raise_softirq_irqoff() but will process them in ksoftirqd
+ */
+void __raise_softirq_irqoff_ksoft(unsigned int nr)
+{
+	unsigned int mask;
+
+	if (WARN_ON_ONCE(!__this_cpu_read(ksoftirqd) ||
+			 !__this_cpu_read(ktimer_softirqd)))
+		return;
+	mask = 1UL << nr;
+
+	trace_softirq_raise(nr);
+	or_softirq_pending(mask);
+	if (mask & TIMER_SOFTIRQS)
+		__this_cpu_read(ktimer_softirqd)->softirqs_raised |= mask;
+	else
+		__this_cpu_read(ksoftirqd)->softirqs_raised |= mask;
+	wakeup_proper_softirq(nr);
+}
+
+/*
+ * This function must run with irqs disabled!
+ */
+void raise_softirq_irqoff(unsigned int nr)
+{
+	do_raise_softirq_irqoff(nr);
+
+	/*
+	 * If we're in an hard interrupt we let irq return code deal
+	 * with the wakeup of ksoftirqd.
+	 */
+	if (in_irq())
+		return;
+	/*
+	 * If we are in thread context but outside of a bh disabled
+	 * region, we need to wake ksoftirqd as well.
+	 *
+	 * CHECKME: Some of the places which do that could be wrapped
+	 * into local_bh_disable/enable pairs. Though it's unclear
+	 * whether this is worth the effort. To find those places just
+	 * raise a WARN() if the condition is met.
+	 */
+	if (!current->softirq_nestcnt)
+		wakeup_proper_softirq(nr);
+}
+
+static inline int ksoftirqd_softirq_pending(void)
+{
+	return current->softirqs_raised;
+}
+
+static inline void local_bh_disable_nort(void) { }
+static inline void _local_bh_enable_nort(void) { }
+
+static inline void ksoftirqd_set_sched_params(unsigned int cpu)
+{
+	/* Take over all but timer pending softirqs when starting */
+	local_irq_disable();
+	current->softirqs_raised = local_softirq_pending() & ~TIMER_SOFTIRQS;
+	local_irq_enable();
+}
+
+static inline void ktimer_softirqd_set_sched_params(unsigned int cpu)
+{
+	struct sched_param param = { .sched_priority = 1 };
+
+	sched_setscheduler(current, SCHED_FIFO, &param);
+
+	/* Take over timer pending softirqs when starting */
+	local_irq_disable();
+	current->softirqs_raised = local_softirq_pending() & TIMER_SOFTIRQS;
+	local_irq_enable();
+}
+
+static inline void ktimer_softirqd_clr_sched_params(unsigned int cpu,
+						    bool online)
+{
+	struct sched_param param = { .sched_priority = 0 };
+
+	sched_setscheduler(current, SCHED_NORMAL, &param);
+}
+
+static int ktimer_softirqd_should_run(unsigned int cpu)
+{
+	return current->softirqs_raised;
+}
+
+#endif /* PREEMPT_RT_FULL */
+/*
  * Enter an interrupt context.
  */
 void irq_enter(void)
@@ -349,9 +821,9 @@ void irq_enter(void)
 		 * Prevent raise_softirq from needlessly waking up ksoftirqd
 		 * here, as softirq will be serviced on return from interrupt.
 		 */
-		local_bh_disable();
+		local_bh_disable_nort();
 		tick_irq_enter();
-		_local_bh_enable();
+		_local_bh_enable_nort();
 	}
 
 	__irq_enter();
@@ -359,6 +831,7 @@ void irq_enter(void)
 
 static inline void invoke_softirq(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	if (ksoftirqd_running(local_softirq_pending()))
 		return;
 
@@ -381,6 +854,18 @@ static inline void invoke_softirq(void)
 	} else {
 		wakeup_softirqd();
 	}
+#else /* PREEMPT_RT_FULL */
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (__this_cpu_read(ksoftirqd) &&
+			__this_cpu_read(ksoftirqd)->softirqs_raised)
+		wakeup_softirqd();
+	if (__this_cpu_read(ktimer_softirqd) &&
+			__this_cpu_read(ktimer_softirqd)->softirqs_raised)
+		wakeup_timer_softirqd();
+	local_irq_restore(flags);
+#endif
 }
 
 static inline void tick_irq_exit(void)
@@ -416,26 +901,6 @@ void irq_exit(void)
 	trace_hardirq_exit(); /* must be last! */
 }
 
-/*
- * This function must run with irqs disabled!
- */
-inline void raise_softirq_irqoff(unsigned int nr)
-{
-	__raise_softirq_irqoff(nr);
-
-	/*
-	 * If we're in an interrupt or softirq, we're done
-	 * (this also catches softirq-disabled code). We will
-	 * actually run the softirq once we return from
-	 * the irq or softirq.
-	 *
-	 * Otherwise we wake up ksoftirqd to make sure we
-	 * schedule the softirq soon.
-	 */
-	if (!in_interrupt())
-		wakeup_softirqd();
-}
-
 void raise_softirq(unsigned int nr)
 {
 	unsigned long flags;
@@ -445,12 +910,6 @@ void raise_softirq(unsigned int nr)
 	local_irq_restore(flags);
 }
 
-void __raise_softirq_irqoff(unsigned int nr)
-{
-	trace_softirq_raise(nr);
-	or_softirq_pending(1UL << nr);
-}
-
 void open_softirq(int nr, void (*action)(struct softirq_action *))
 {
 	softirq_vec[nr].action = action;
@@ -475,11 +934,38 @@ static void __tasklet_schedule_common(st
 	unsigned long flags;
 
 	local_irq_save(flags);
+	if (!tasklet_trylock(t)) {
+		local_irq_restore(flags);
+		return;
+	}
+
 	head = this_cpu_ptr(headp);
-	t->next = NULL;
-	*head->tail = t;
-	head->tail = &(t->next);
-	raise_softirq_irqoff(softirq_nr);
+again:
+	/* We may have been preempted before tasklet_trylock
+	 * and __tasklet_action may have already run.
+	 * So double check the sched bit while the takslet
+	 * is locked before adding it to the list.
+	 */
+	if (test_bit(TASKLET_STATE_SCHED, &t->state)) {
+		t->next = NULL;
+		*head->tail = t;
+		head->tail = &(t->next);
+		raise_softirq_irqoff(softirq_nr);
+		tasklet_unlock(t);
+	} else {
+		/* This is subtle. If we hit the corner case above
+		 * It is possible that we get preempted right here,
+		 * and another task has successfully called
+		 * tasklet_schedule(), then this function, and
+		 * failed on the trylock. Thus we must be sure
+		 * before releasing the tasklet lock, that the
+		 * SCHED_BIT is clear. Otherwise the tasklet
+		 * may get its SCHED_BIT set, but not added to the
+		 * list
+		 */
+		if (!tasklet_tryunlock(t))
+			goto again;
+	}
 	local_irq_restore(flags);
 }
 
@@ -497,11 +983,21 @@ void __tasklet_hi_schedule(struct taskle
 }
 EXPORT_SYMBOL(__tasklet_hi_schedule);
 
+void tasklet_enable(struct tasklet_struct *t)
+{
+	if (!atomic_dec_and_test(&t->count))
+		return;
+	if (test_and_clear_bit(TASKLET_STATE_PENDING, &t->state))
+		tasklet_schedule(t);
+}
+EXPORT_SYMBOL(tasklet_enable);
+
 static void tasklet_action_common(struct softirq_action *a,
 				  struct tasklet_head *tl_head,
 				  unsigned int softirq_nr)
 {
 	struct tasklet_struct *list;
+	int loops = 1000000;
 
 	local_irq_disable();
 	list = tl_head->head;
@@ -513,25 +1009,56 @@ static void tasklet_action_common(struct
 		struct tasklet_struct *t = list;
 
 		list = list->next;
+		/*
+		 * Should always succeed - after a tasklist got on the
+		 * list (after getting the SCHED bit set from 0 to 1),
+		 * nothing but the tasklet softirq it got queued to can
+		 * lock it:
+		 */
+		if (!tasklet_trylock(t)) {
+			WARN_ON(1);
+			continue;
+		}
 
-		if (tasklet_trylock(t)) {
-			if (!atomic_read(&t->count)) {
-				if (!test_and_clear_bit(TASKLET_STATE_SCHED,
-							&t->state))
-					BUG();
-				t->func(t->data);
+		t->next = NULL;
+
+		if (unlikely(atomic_read(&t->count))) {
+out_disabled:
+			/* implicit unlock: */
+			wmb();
+			t->state = TASKLET_STATEF_PENDING;
+			continue;
+		}
+		/*
+		 * After this point on the tasklet might be rescheduled
+		 * on another CPU, but it can only be added to another
+		 * CPU's tasklet list if we unlock the tasklet (which we
+		 * dont do yet).
+		 */
+		if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+			WARN_ON(1);
+again:
+		t->func(t->data);
+
+		while (!tasklet_tryunlock(t)) {
+			/*
+			 * If it got disabled meanwhile, bail out:
+			 */
+			if (atomic_read(&t->count))
+				goto out_disabled;
+			/*
+			 * If it got scheduled meanwhile, re-execute
+			 * the tasklet function:
+			 */
+			if (test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+				goto again;
+			if (!--loops) {
+				printk("hm, tasklet state: %08lx\n", t->state);
+				WARN_ON(1);
 				tasklet_unlock(t);
-				continue;
+				break;
 			}
-			tasklet_unlock(t);
 		}
-
-		local_irq_disable();
-		t->next = NULL;
-		*tl_head->tail = t;
-		tl_head->tail = &t->next;
-		__raise_softirq_irqoff(softirq_nr);
-		local_irq_enable();
 	}
 }
 
@@ -563,7 +1090,7 @@ void tasklet_kill(struct tasklet_struct
 
 	while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) {
 		do {
-			yield();
+			msleep(1);
 		} while (test_bit(TASKLET_STATE_SCHED, &t->state));
 	}
 	tasklet_unlock_wait(t);
@@ -637,25 +1164,26 @@ void __init softirq_init(void)
 	open_softirq(HI_SOFTIRQ, tasklet_hi_action);
 }
 
-static int ksoftirqd_should_run(unsigned int cpu)
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
+void tasklet_unlock_wait(struct tasklet_struct *t)
 {
-	return local_softirq_pending();
-}
-
-static void run_ksoftirqd(unsigned int cpu)
-{
-	local_irq_disable();
-	if (local_softirq_pending()) {
+	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) {
 		/*
-		 * We can safely run softirq on inline stack, as we are not deep
-		 * in the task stack here.
+		 * Hack for now to avoid this busy-loop:
 		 */
-		__do_softirq();
-		local_irq_enable();
-		cond_resched();
-		return;
+#ifdef CONFIG_PREEMPT_RT_FULL
+		msleep(1);
+#else
+		barrier();
+#endif
 	}
-	local_irq_enable();
+}
+EXPORT_SYMBOL(tasklet_unlock_wait);
+#endif
+
+static int ksoftirqd_should_run(unsigned int cpu)
+{
+	return ksoftirqd_softirq_pending();
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -722,17 +1250,31 @@ static int takeover_tasklets(unsigned in
 
 static struct smp_hotplug_thread softirq_threads = {
 	.store			= &ksoftirqd,
+	.setup			= ksoftirqd_set_sched_params,
 	.thread_should_run	= ksoftirqd_should_run,
 	.thread_fn		= run_ksoftirqd,
 	.thread_comm		= "ksoftirqd/%u",
 };
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static struct smp_hotplug_thread softirq_timer_threads = {
+	.store			= &ktimer_softirqd,
+	.setup			= ktimer_softirqd_set_sched_params,
+	.cleanup		= ktimer_softirqd_clr_sched_params,
+	.thread_should_run	= ktimer_softirqd_should_run,
+	.thread_fn		= run_ksoftirqd,
+	.thread_comm		= "ktimersoftd/%u",
+};
+#endif
+
 static __init int spawn_ksoftirqd(void)
 {
 	cpuhp_setup_state_nocalls(CPUHP_SOFTIRQ_DEAD, "softirq:dead", NULL,
 				  takeover_tasklets);
 	BUG_ON(smpboot_register_percpu_thread(&softirq_threads));
-
+#ifdef CONFIG_PREEMPT_RT_FULL
+	BUG_ON(smpboot_register_percpu_thread(&softirq_timer_threads));
+#endif
 	return 0;
 }
 early_initcall(spawn_ksoftirqd);
Index: linux-4.19.25-rt16/kernel/time/alarmtimer.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/alarmtimer.c
+++ linux-4.19.25-rt16/kernel/time/alarmtimer.c
@@ -436,7 +436,7 @@ int alarm_cancel(struct alarm *alarm)
 		int ret = alarm_try_to_cancel(alarm);
 		if (ret >= 0)
 			return ret;
-		cpu_relax();
+		hrtimer_wait_for_timer(&alarm->timer);
 	}
 }
 EXPORT_SYMBOL_GPL(alarm_cancel);
Index: linux-4.19.25-rt16/kernel/time/hrtimer.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/hrtimer.c
+++ linux-4.19.25-rt16/kernel/time/hrtimer.c
@@ -730,6 +730,29 @@ static void hrtimer_switch_to_hres(void)
 	retrigger_next_event(NULL);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+
+static struct swork_event clock_set_delay_work;
+
+static void run_clock_set_delay(struct swork_event *event)
+{
+	clock_was_set();
+}
+
+void clock_was_set_delayed(void)
+{
+	swork_queue(&clock_set_delay_work);
+}
+
+static __init int create_clock_set_delay_thread(void)
+{
+	WARN_ON(swork_get());
+	INIT_SWORK(&clock_set_delay_work, run_clock_set_delay);
+	return 0;
+}
+early_initcall(create_clock_set_delay_thread);
+#else /* PREEMPT_RT_FULL */
+
 static void clock_was_set_work(struct work_struct *work)
 {
 	clock_was_set();
@@ -745,6 +768,7 @@ void clock_was_set_delayed(void)
 {
 	schedule_work(&hrtimer_work);
 }
+#endif
 
 #else
 
@@ -939,6 +963,33 @@ u64 hrtimer_forward(struct hrtimer *time
 }
 EXPORT_SYMBOL_GPL(hrtimer_forward);
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define wake_up_timer_waiters(b)	wake_up(&(b)->wait)
+
+/**
+ * hrtimer_wait_for_timer - Wait for a running timer
+ *
+ * @timer:	timer to wait for
+ *
+ * The function waits in case the timers callback function is
+ * currently executed on the waitqueue of the timer base. The
+ * waitqueue is woken up after the timer callback function has
+ * finished execution.
+ */
+void hrtimer_wait_for_timer(const struct hrtimer *timer)
+{
+	struct hrtimer_clock_base *base = timer->base;
+
+	if (base && base->cpu_base &&
+	    base->index >= HRTIMER_BASE_MONOTONIC_SOFT)
+		wait_event(base->cpu_base->wait,
+				!(hrtimer_callback_running(timer)));
+}
+
+#else
+# define wake_up_timer_waiters(b)	do { } while (0)
+#endif
+
 /*
  * enqueue_hrtimer - internal function to (re)start a timer
  *
@@ -1108,7 +1159,9 @@ void hrtimer_start_range_ns(struct hrtim
 	 * Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft
 	 * match.
 	 */
+#ifndef CONFIG_PREEMPT_RT_BASE
 	WARN_ON_ONCE(!(mode & HRTIMER_MODE_SOFT) ^ !timer->is_soft);
+#endif
 
 	base = lock_hrtimer_base(timer, &flags);
 
@@ -1171,7 +1224,7 @@ int hrtimer_cancel(struct hrtimer *timer
 
 		if (ret >= 0)
 			return ret;
-		cpu_relax();
+		hrtimer_wait_for_timer(timer);
 	}
 }
 EXPORT_SYMBOL_GPL(hrtimer_cancel);
@@ -1268,10 +1321,17 @@ static inline int hrtimer_clockid_to_bas
 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 			   enum hrtimer_mode mode)
 {
-	bool softtimer = !!(mode & HRTIMER_MODE_SOFT);
-	int base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0;
+	bool softtimer;
+	int base;
 	struct hrtimer_cpu_base *cpu_base;
 
+	softtimer = !!(mode & HRTIMER_MODE_SOFT);
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (!softtimer && !(mode & HRTIMER_MODE_HARD))
+		softtimer = true;
+#endif
+	base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0;
+
 	memset(timer, 0, sizeof(struct hrtimer));
 
 	cpu_base = raw_cpu_ptr(&hrtimer_bases);
@@ -1477,6 +1537,7 @@ static __latent_entropy void hrtimer_run
 	hrtimer_update_softirq_timer(cpu_base, true);
 
 	raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
+	wake_up_timer_waiters(cpu_base);
 }
 
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -1648,13 +1709,52 @@ static enum hrtimer_restart hrtimer_wake
 	return HRTIMER_NORESTART;
 }
 
-void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
-{
+static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
+				   clockid_t clock_id,
+				   enum hrtimer_mode mode,
+				   struct task_struct *task)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (!(mode & (HRTIMER_MODE_SOFT | HRTIMER_MODE_HARD))) {
+		if (task_is_realtime(current) || system_state != SYSTEM_RUNNING)
+			mode |= HRTIMER_MODE_HARD;
+		else
+			mode |= HRTIMER_MODE_SOFT;
+	}
+#endif
+	__hrtimer_init(&sl->timer, clock_id, mode);
 	sl->timer.function = hrtimer_wakeup;
 	sl->task = task;
 }
+
+/**
+ * hrtimer_init_sleeper - initialize sleeper to the given clock
+ * @sl:		sleeper to be initialized
+ * @clock_id:	the clock to be used
+ * @mode:	timer mode abs/rel
+ * @task:	the task to wake up
+ */
+void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
+			  enum hrtimer_mode mode, struct task_struct *task)
+{
+	debug_init(&sl->timer, clock_id, mode);
+	__hrtimer_init_sleeper(sl, clock_id, mode, task);
+
+}
 EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
 
+#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
+void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+				   clockid_t clock_id,
+				   enum hrtimer_mode mode,
+				   struct task_struct *task)
+{
+	debug_object_init_on_stack(&sl->timer, &hrtimer_debug_descr);
+	__hrtimer_init_sleeper(sl, clock_id, mode, task);
+}
+EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack);
+#endif
+
 int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts)
 {
 	switch(restart->nanosleep.type) {
@@ -1678,8 +1778,6 @@ static int __sched do_nanosleep(struct h
 {
 	struct restart_block *restart;
 
-	hrtimer_init_sleeper(t, current);
-
 	do {
 		set_current_state(TASK_INTERRUPTIBLE);
 		hrtimer_start_expires(&t->timer, mode);
@@ -1687,12 +1785,12 @@ static int __sched do_nanosleep(struct h
 		if (likely(t->task))
 			freezable_schedule();
 
+		__set_current_state(TASK_RUNNING);
 		hrtimer_cancel(&t->timer);
 		mode = HRTIMER_MODE_ABS;
 
 	} while (t->task && !signal_pending(current));
 
-	__set_current_state(TASK_RUNNING);
 
 	if (!t->task)
 		return 0;
@@ -1716,10 +1814,9 @@ static long __sched hrtimer_nanosleep_re
 	struct hrtimer_sleeper t;
 	int ret;
 
-	hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid,
-				HRTIMER_MODE_ABS);
+	hrtimer_init_sleeper_on_stack(&t, restart->nanosleep.clockid,
+				      HRTIMER_MODE_ABS, current);
 	hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
-
 	ret = do_nanosleep(&t, HRTIMER_MODE_ABS);
 	destroy_hrtimer_on_stack(&t.timer);
 	return ret;
@@ -1737,7 +1834,7 @@ long hrtimer_nanosleep(const struct time
 	if (dl_task(current) || rt_task(current))
 		slack = 0;
 
-	hrtimer_init_on_stack(&t.timer, clockid, mode);
+	hrtimer_init_sleeper_on_stack(&t, clockid, mode, current);
 	hrtimer_set_expires_range_ns(&t.timer, timespec64_to_ktime(*rqtp), slack);
 	ret = do_nanosleep(&t, mode);
 	if (ret != -ERESTART_RESTARTBLOCK)
@@ -1797,6 +1894,38 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct
 }
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Sleep for 1 ms in hope whoever holds what we want will let it go.
+ */
+void cpu_chill(void)
+{
+	unsigned int freeze_flag = current->flags & PF_NOFREEZE;
+	struct task_struct *self = current;
+	ktime_t chill_time;
+
+	raw_spin_lock_irq(&self->pi_lock);
+	self->saved_state = self->state;
+	__set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+	raw_spin_unlock_irq(&self->pi_lock);
+
+	chill_time = ktime_set(0, NSEC_PER_MSEC);
+
+	current->flags |= PF_NOFREEZE;
+	sleeping_lock_inc();
+	schedule_hrtimeout(&chill_time, HRTIMER_MODE_REL_HARD);
+	sleeping_lock_dec();
+	if (!freeze_flag)
+		current->flags &= ~PF_NOFREEZE;
+
+	raw_spin_lock_irq(&self->pi_lock);
+	__set_current_state_no_track(self->saved_state);
+	self->saved_state = TASK_RUNNING;
+	raw_spin_unlock_irq(&self->pi_lock);
+}
+EXPORT_SYMBOL(cpu_chill);
+#endif
+
 /*
  * Functions related to boot-time initialization:
  */
@@ -1818,6 +1947,9 @@ int hrtimers_prepare_cpu(unsigned int cp
 	cpu_base->softirq_next_timer = NULL;
 	cpu_base->expires_next = KTIME_MAX;
 	cpu_base->softirq_expires_next = KTIME_MAX;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	init_waitqueue_head(&cpu_base->wait);
+#endif
 	return 0;
 }
 
@@ -1936,11 +2068,9 @@ schedule_hrtimeout_range_clock(ktime_t *
 		return -EINTR;
 	}
 
-	hrtimer_init_on_stack(&t.timer, clock_id, mode);
+	hrtimer_init_sleeper_on_stack(&t, clock_id, mode, current);
 	hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
 
-	hrtimer_init_sleeper(&t, current);
-
 	hrtimer_start_expires(&t.timer, mode);
 
 	if (likely(t.task))
Index: linux-4.19.25-rt16/kernel/time/itimer.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/itimer.c
+++ linux-4.19.25-rt16/kernel/time/itimer.c
@@ -215,6 +215,7 @@ again:
 		/* We are sharing ->siglock with it_real_fn() */
 		if (hrtimer_try_to_cancel(timer) < 0) {
 			spin_unlock_irq(&tsk->sighand->siglock);
+			hrtimer_wait_for_timer(&tsk->signal->real_timer);
 			goto again;
 		}
 		expires = timeval_to_ktime(value->it_value);
Index: linux-4.19.25-rt16/kernel/time/jiffies.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/jiffies.c
+++ linux-4.19.25-rt16/kernel/time/jiffies.c
@@ -74,7 +74,8 @@ static struct clocksource clocksource_ji
 	.max_cycles	= 10,
 };
 
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(jiffies_lock);
+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(jiffies_lock);
+__cacheline_aligned_in_smp seqcount_t jiffies_seq;
 
 #if (BITS_PER_LONG < 64)
 u64 get_jiffies_64(void)
@@ -83,9 +84,9 @@ u64 get_jiffies_64(void)
 	u64 ret;
 
 	do {
-		seq = read_seqbegin(&jiffies_lock);
+		seq = read_seqcount_begin(&jiffies_seq);
 		ret = jiffies_64;
-	} while (read_seqretry(&jiffies_lock, seq));
+	} while (read_seqcount_retry(&jiffies_seq, seq));
 	return ret;
 }
 EXPORT_SYMBOL(get_jiffies_64);
Index: linux-4.19.25-rt16/kernel/time/posix-cpu-timers.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/posix-cpu-timers.c
+++ linux-4.19.25-rt16/kernel/time/posix-cpu-timers.c
@@ -3,8 +3,10 @@
  * Implement CPU time clocks for the POSIX clock interface.
  */
 
+#include <uapi/linux/sched/types.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/cputime.h>
+#include <linux/sched/rt.h>
 #include <linux/posix-timers.h>
 #include <linux/errno.h>
 #include <linux/math64.h>
@@ -15,6 +17,7 @@
 #include <linux/workqueue.h>
 #include <linux/compat.h>
 #include <linux/sched/deadline.h>
+#include <linux/smpboot.h>
 
 #include "posix-timers.h"
 
@@ -1136,14 +1139,12 @@ static inline int fastpath_timer_check(s
  * already updated our counts.  We need to check if any timers fire now.
  * Interrupts are disabled.
  */
-void run_posix_cpu_timers(struct task_struct *tsk)
+static void __run_posix_cpu_timers(struct task_struct *tsk)
 {
 	LIST_HEAD(firing);
 	struct k_itimer *timer, *next;
 	unsigned long flags;
 
-	lockdep_assert_irqs_disabled();
-
 	/*
 	 * The fast path checks that there are no expired thread or thread
 	 * group timers.  If that's so, just return.
@@ -1196,6 +1197,153 @@ void run_posix_cpu_timers(struct task_st
 	}
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+#include <linux/kthread.h>
+#include <linux/cpu.h>
+DEFINE_PER_CPU(struct task_struct *, posix_timer_task);
+DEFINE_PER_CPU(struct task_struct *, posix_timer_tasklist);
+DEFINE_PER_CPU(bool, posix_timer_th_active);
+
+static void posix_cpu_kthread_fn(unsigned int cpu)
+{
+	struct task_struct *tsk = NULL;
+	struct task_struct *next = NULL;
+
+	BUG_ON(per_cpu(posix_timer_task, cpu) != current);
+
+	/* grab task list */
+	raw_local_irq_disable();
+	tsk = per_cpu(posix_timer_tasklist, cpu);
+	per_cpu(posix_timer_tasklist, cpu) = NULL;
+	raw_local_irq_enable();
+
+	/* its possible the list is empty, just return */
+	if (!tsk)
+		return;
+
+	/* Process task list */
+	while (1) {
+		/* save next */
+		next = tsk->posix_timer_list;
+
+		/* run the task timers, clear its ptr and
+		 * unreference it
+		 */
+		__run_posix_cpu_timers(tsk);
+		tsk->posix_timer_list = NULL;
+		put_task_struct(tsk);
+
+		/* check if this is the last on the list */
+		if (next == tsk)
+			break;
+		tsk = next;
+	}
+}
+
+static inline int __fastpath_timer_check(struct task_struct *tsk)
+{
+	/* tsk == current, ensure it is safe to use ->signal/sighand */
+	if (unlikely(tsk->exit_state))
+		return 0;
+
+	if (!task_cputime_zero(&tsk->cputime_expires))
+			return 1;
+
+	if (!task_cputime_zero(&tsk->signal->cputime_expires))
+			return 1;
+
+	return 0;
+}
+
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+	unsigned int cpu = smp_processor_id();
+	struct task_struct *tasklist;
+
+	BUG_ON(!irqs_disabled());
+
+	if (per_cpu(posix_timer_th_active, cpu) != true)
+		return;
+
+	/* get per-cpu references */
+	tasklist = per_cpu(posix_timer_tasklist, cpu);
+
+	/* check to see if we're already queued */
+	if (!tsk->posix_timer_list && __fastpath_timer_check(tsk)) {
+		get_task_struct(tsk);
+		if (tasklist) {
+			tsk->posix_timer_list = tasklist;
+		} else {
+			/*
+			 * The list is terminated by a self-pointing
+			 * task_struct
+			 */
+			tsk->posix_timer_list = tsk;
+		}
+		per_cpu(posix_timer_tasklist, cpu) = tsk;
+
+		wake_up_process(per_cpu(posix_timer_task, cpu));
+	}
+}
+
+static int posix_cpu_kthread_should_run(unsigned int cpu)
+{
+	return __this_cpu_read(posix_timer_tasklist) != NULL;
+}
+
+static void posix_cpu_kthread_park(unsigned int cpu)
+{
+	this_cpu_write(posix_timer_th_active, false);
+}
+
+static void posix_cpu_kthread_unpark(unsigned int cpu)
+{
+	this_cpu_write(posix_timer_th_active, true);
+}
+
+static void posix_cpu_kthread_setup(unsigned int cpu)
+{
+	struct sched_param sp;
+
+	sp.sched_priority = MAX_RT_PRIO - 1;
+	sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
+	posix_cpu_kthread_unpark(cpu);
+}
+
+static struct smp_hotplug_thread posix_cpu_thread = {
+	.store			= &posix_timer_task,
+	.thread_should_run	= posix_cpu_kthread_should_run,
+	.thread_fn		= posix_cpu_kthread_fn,
+	.thread_comm		= "posixcputmr/%u",
+	.setup			= posix_cpu_kthread_setup,
+	.park			= posix_cpu_kthread_park,
+	.unpark			= posix_cpu_kthread_unpark,
+};
+
+static int __init posix_cpu_thread_init(void)
+{
+	/* Start one for boot CPU. */
+	unsigned long cpu;
+	int ret;
+
+	/* init the per-cpu posix_timer_tasklets */
+	for_each_possible_cpu(cpu)
+		per_cpu(posix_timer_tasklist, cpu) = NULL;
+
+	ret = smpboot_register_percpu_thread(&posix_cpu_thread);
+	WARN_ON(ret);
+
+	return 0;
+}
+early_initcall(posix_cpu_thread_init);
+#else /* CONFIG_PREEMPT_RT_BASE */
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+	lockdep_assert_irqs_disabled();
+	__run_posix_cpu_timers(tsk);
+}
+#endif /* CONFIG_PREEMPT_RT_BASE */
+
 /*
  * Set one of the process-wide special case CPU timers or RLIMIT_CPU.
  * The tsk->sighand->siglock must be held by the caller.
Index: linux-4.19.25-rt16/kernel/time/posix-timers.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/posix-timers.c
+++ linux-4.19.25-rt16/kernel/time/posix-timers.c
@@ -463,7 +463,7 @@ static struct k_itimer * alloc_posix_tim
 
 static void k_itimer_rcu_free(struct rcu_head *head)
 {
-	struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu);
+	struct k_itimer *tmr = container_of(head, struct k_itimer, rcu);
 
 	kmem_cache_free(posix_timers_cache, tmr);
 }
@@ -480,7 +480,7 @@ static void release_posix_timer(struct k
 	}
 	put_pid(tmr->it_pid);
 	sigqueue_free(tmr->sigq);
-	call_rcu(&tmr->it.rcu, k_itimer_rcu_free);
+	call_rcu(&tmr->rcu, k_itimer_rcu_free);
 }
 
 static int common_timer_create(struct k_itimer *new_timer)
@@ -821,6 +821,22 @@ static void common_hrtimer_arm(struct k_
 		hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
+/*
+ * Protected by RCU!
+ */
+static void timer_wait_for_callback(const struct k_clock *kc, struct k_itimer *timr)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (kc->timer_arm == common_hrtimer_arm)
+		hrtimer_wait_for_timer(&timr->it.real.timer);
+	else if (kc == &alarm_clock)
+		hrtimer_wait_for_timer(&timr->it.alarm.alarmtimer.timer);
+	else
+		/* FIXME: Whacky hack for posix-cpu-timers */
+		schedule_timeout(1);
+#endif
+}
+
 static int common_hrtimer_try_to_cancel(struct k_itimer *timr)
 {
 	return hrtimer_try_to_cancel(&timr->it.real.timer);
@@ -885,6 +901,7 @@ retry:
 	if (!timr)
 		return -EINVAL;
 
+	rcu_read_lock();
 	kc = timr->kclock;
 	if (WARN_ON_ONCE(!kc || !kc->timer_set))
 		error = -EINVAL;
@@ -893,9 +910,12 @@ retry:
 
 	unlock_timer(timr, flag);
 	if (error == TIMER_RETRY) {
+		timer_wait_for_callback(kc, timr);
 		old_spec64 = NULL;	// We already got the old time...
+		rcu_read_unlock();
 		goto retry;
 	}
+	rcu_read_unlock();
 
 	return error;
 }
@@ -977,10 +997,15 @@ retry_delete:
 	if (!timer)
 		return -EINVAL;
 
+	rcu_read_lock();
 	if (timer_delete_hook(timer) == TIMER_RETRY) {
 		unlock_timer(timer, flags);
+		timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
+					timer);
+		rcu_read_unlock();
 		goto retry_delete;
 	}
+	rcu_read_unlock();
 
 	spin_lock(&current->sighand->siglock);
 	list_del(&timer->list);
@@ -1006,8 +1031,18 @@ static void itimer_delete(struct k_itime
 retry_delete:
 	spin_lock_irqsave(&timer->it_lock, flags);
 
+	/* On RT we can race with a deletion */
+	if (!timer->it_signal) {
+		unlock_timer(timer, flags);
+		return;
+	}
+
 	if (timer_delete_hook(timer) == TIMER_RETRY) {
+		rcu_read_lock();
 		unlock_timer(timer, flags);
+		timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
+					timer);
+		rcu_read_unlock();
 		goto retry_delete;
 	}
 	list_del(&timer->list);
Index: linux-4.19.25-rt16/kernel/time/tick-broadcast-hrtimer.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/tick-broadcast-hrtimer.c
+++ linux-4.19.25-rt16/kernel/time/tick-broadcast-hrtimer.c
@@ -106,7 +106,7 @@ static enum hrtimer_restart bc_handler(s
 
 void tick_setup_hrtimer_broadcast(void)
 {
-	hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 	bctimer.function = bc_handler;
 	clockevents_register_device(&ce_broadcast_hrtimer);
 }
Index: linux-4.19.25-rt16/kernel/time/tick-common.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/tick-common.c
+++ linux-4.19.25-rt16/kernel/time/tick-common.c
@@ -79,13 +79,15 @@ int tick_is_oneshot_available(void)
 static void tick_periodic(int cpu)
 {
 	if (tick_do_timer_cpu == cpu) {
-		write_seqlock(&jiffies_lock);
+		raw_spin_lock(&jiffies_lock);
+		write_seqcount_begin(&jiffies_seq);
 
 		/* Keep track of the next tick event */
 		tick_next_period = ktime_add(tick_next_period, tick_period);
 
 		do_timer(1);
-		write_sequnlock(&jiffies_lock);
+		write_seqcount_end(&jiffies_seq);
+		raw_spin_unlock(&jiffies_lock);
 		update_wall_time();
 	}
 
@@ -157,9 +159,9 @@ void tick_setup_periodic(struct clock_ev
 		ktime_t next;
 
 		do {
-			seq = read_seqbegin(&jiffies_lock);
+			seq = read_seqcount_begin(&jiffies_seq);
 			next = tick_next_period;
-		} while (read_seqretry(&jiffies_lock, seq));
+		} while (read_seqcount_retry(&jiffies_seq, seq));
 
 		clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
 
Index: linux-4.19.25-rt16/kernel/time/tick-sched.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/tick-sched.c
+++ linux-4.19.25-rt16/kernel/time/tick-sched.c
@@ -67,7 +67,8 @@ static void tick_do_update_jiffies64(kti
 		return;
 
 	/* Reevaluate with jiffies_lock held */
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 
 	delta = ktime_sub(now, last_jiffies_update);
 	if (delta >= tick_period) {
@@ -90,10 +91,12 @@ static void tick_do_update_jiffies64(kti
 		/* Keep the tick_next_period variable up to date */
 		tick_next_period = ktime_add(last_jiffies_update, tick_period);
 	} else {
-		write_sequnlock(&jiffies_lock);
+		write_seqcount_end(&jiffies_seq);
+		raw_spin_unlock(&jiffies_lock);
 		return;
 	}
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	update_wall_time();
 }
 
@@ -104,12 +107,14 @@ static ktime_t tick_init_jiffy_update(vo
 {
 	ktime_t period;
 
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 	/* Did we start the jiffies update yet ? */
 	if (last_jiffies_update == 0)
 		last_jiffies_update = tick_next_period;
 	period = last_jiffies_update;
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	return period;
 }
 
@@ -227,6 +232,7 @@ static void nohz_full_kick_func(struct i
 
 static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
 	.func = nohz_full_kick_func,
+	.flags = IRQ_WORK_HARD_IRQ,
 };
 
 /*
@@ -652,10 +658,10 @@ static ktime_t tick_nohz_next_event(stru
 
 	/* Read jiffies and the time when jiffies were updated last */
 	do {
-		seq = read_seqbegin(&jiffies_lock);
+		seq = read_seqcount_begin(&jiffies_seq);
 		basemono = last_jiffies_update;
 		basejiff = jiffies;
-	} while (read_seqretry(&jiffies_lock, seq));
+	} while (read_seqcount_retry(&jiffies_seq, seq));
 	ts->last_jiffies = basejiff;
 	ts->timer_expires_base = basemono;
 
@@ -886,14 +892,7 @@ static bool can_stop_idle_tick(int cpu,
 		return false;
 
 	if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
-		static int ratelimit;
-
-		if (ratelimit < 10 &&
-		    (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
-			pr_warn("NOHZ: local_softirq_pending %02x\n",
-				(unsigned int) local_softirq_pending());
-			ratelimit++;
-		}
+		softirq_check_pending_idle();
 		return false;
 	}
 
@@ -1305,7 +1304,7 @@ void tick_setup_sched_timer(void)
 	/*
 	 * Emulate tick processing via per-CPU hrtimers:
 	 */
-	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 	ts->sched_timer.function = tick_sched_timer;
 
 	/* Get the next period (per-CPU) */
Index: linux-4.19.25-rt16/kernel/time/timekeeping.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/timekeeping.c
+++ linux-4.19.25-rt16/kernel/time/timekeeping.c
@@ -2417,8 +2417,10 @@ EXPORT_SYMBOL(hardpps);
  */
 void xtime_update(unsigned long ticks)
 {
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 	do_timer(ticks);
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	update_wall_time();
 }
Index: linux-4.19.25-rt16/kernel/time/timekeeping.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/timekeeping.h
+++ linux-4.19.25-rt16/kernel/time/timekeeping.h
@@ -25,7 +25,8 @@ static inline void sched_clock_resume(vo
 extern void do_timer(unsigned long ticks);
 extern void update_wall_time(void);
 
-extern seqlock_t jiffies_lock;
+extern raw_spinlock_t jiffies_lock;
+extern seqcount_t jiffies_seq;
 
 #define CS_NAME_LEN	32
 
Index: linux-4.19.25-rt16/kernel/time/timer.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/time/timer.c
+++ linux-4.19.25-rt16/kernel/time/timer.c
@@ -44,6 +44,7 @@
 #include <linux/sched/debug.h>
 #include <linux/slab.h>
 #include <linux/compat.h>
+#include <linux/swait.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
@@ -197,6 +198,9 @@ EXPORT_SYMBOL(jiffies_64);
 struct timer_base {
 	raw_spinlock_t		lock;
 	struct timer_list	*running_timer;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	struct swait_queue_head	wait_for_running_timer;
+#endif
 	unsigned long		clk;
 	unsigned long		next_expiry;
 	unsigned int		cpu;
@@ -213,8 +217,7 @@ static DEFINE_PER_CPU(struct timer_base,
 static DEFINE_STATIC_KEY_FALSE(timers_nohz_active);
 static DEFINE_MUTEX(timer_keys_mutex);
 
-static void timer_update_keys(struct work_struct *work);
-static DECLARE_WORK(timer_update_work, timer_update_keys);
+static struct swork_event timer_update_swork;
 
 #ifdef CONFIG_SMP
 unsigned int sysctl_timer_migration = 1;
@@ -232,7 +235,7 @@ static void timers_update_migration(void
 static inline void timers_update_migration(void) { }
 #endif /* !CONFIG_SMP */
 
-static void timer_update_keys(struct work_struct *work)
+static void timer_update_keys(struct swork_event *event)
 {
 	mutex_lock(&timer_keys_mutex);
 	timers_update_migration();
@@ -242,8 +245,16 @@ static void timer_update_keys(struct wor
 
 void timers_update_nohz(void)
 {
-	schedule_work(&timer_update_work);
+	swork_queue(&timer_update_swork);
+}
+
+static __init int hrtimer_init_thread(void)
+{
+	WARN_ON(swork_get());
+	INIT_SWORK(&timer_update_swork, timer_update_keys);
+	return 0;
 }
+early_initcall(hrtimer_init_thread);
 
 int timer_migration_handler(struct ctl_table *table, int write,
 			    void __user *buffer, size_t *lenp,
@@ -1178,6 +1189,33 @@ void add_timer_on(struct timer_list *tim
 }
 EXPORT_SYMBOL_GPL(add_timer_on);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Wait for a running timer
+ */
+static void wait_for_running_timer(struct timer_list *timer)
+{
+	struct timer_base *base;
+	u32 tf = timer->flags;
+
+	if (tf & TIMER_MIGRATING)
+		return;
+
+	base = get_timer_base(tf);
+	swait_event_exclusive(base->wait_for_running_timer,
+			      base->running_timer != timer);
+}
+
+# define wakeup_timer_waiters(b)	swake_up_all(&(b)->wait_for_running_timer)
+#else
+static inline void wait_for_running_timer(struct timer_list *timer)
+{
+	cpu_relax();
+}
+
+# define wakeup_timer_waiters(b)	do { } while (0)
+#endif
+
 /**
  * del_timer - deactivate a timer.
  * @timer: the timer to be deactivated
@@ -1233,7 +1271,7 @@ int try_to_del_timer_sync(struct timer_l
 }
 EXPORT_SYMBOL(try_to_del_timer_sync);
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
 /**
  * del_timer_sync - deactivate a timer and wait for the handler to finish.
  * @timer: the timer to be deactivated
@@ -1293,7 +1331,7 @@ int del_timer_sync(struct timer_list *ti
 		int ret = try_to_del_timer_sync(timer);
 		if (ret >= 0)
 			return ret;
-		cpu_relax();
+		wait_for_running_timer(timer);
 	}
 }
 EXPORT_SYMBOL(del_timer_sync);
@@ -1354,13 +1392,16 @@ static void expire_timers(struct timer_b
 
 		fn = timer->function;
 
-		if (timer->flags & TIMER_IRQSAFE) {
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL) &&
+		    timer->flags & TIMER_IRQSAFE) {
 			raw_spin_unlock(&base->lock);
 			call_timer_fn(timer, fn);
+			base->running_timer = NULL;
 			raw_spin_lock(&base->lock);
 		} else {
 			raw_spin_unlock_irq(&base->lock);
 			call_timer_fn(timer, fn);
+			base->running_timer = NULL;
 			raw_spin_lock_irq(&base->lock);
 		}
 	}
@@ -1681,8 +1722,8 @@ static inline void __run_timers(struct t
 		while (levels--)
 			expire_timers(base, heads + levels);
 	}
-	base->running_timer = NULL;
 	raw_spin_unlock_irq(&base->lock);
+	wakeup_timer_waiters(base);
 }
 
 /*
@@ -1692,6 +1733,8 @@ static __latent_entropy void run_timer_s
 {
 	struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
 
+	irq_work_tick_soft();
+
 	__run_timers(base);
 	if (IS_ENABLED(CONFIG_NO_HZ_COMMON))
 		__run_timers(this_cpu_ptr(&timer_bases[BASE_DEF]));
@@ -1927,6 +1970,9 @@ static void __init init_timer_cpu(int cp
 		base->cpu = cpu;
 		raw_spin_lock_init(&base->lock);
 		base->clk = jiffies;
+#ifdef CONFIG_PREEMPT_RT_FULL
+		init_swait_queue_head(&base->wait_for_running_timer);
+#endif
 	}
 }
 
Index: linux-4.19.25-rt16/kernel/trace/trace.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/trace/trace.c
+++ linux-4.19.25-rt16/kernel/trace/trace.c
@@ -2134,6 +2134,7 @@ tracing_generic_entry_update(struct trac
 	struct task_struct *tsk = current;
 
 	entry->preempt_count		= pc & 0xff;
+	entry->preempt_lazy_count	= preempt_lazy_count();
 	entry->pid			= (tsk) ? tsk->pid : 0;
 	entry->flags =
 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
@@ -2144,8 +2145,11 @@ tracing_generic_entry_update(struct trac
 		((pc & NMI_MASK    ) ? TRACE_FLAG_NMI     : 0) |
 		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
 		((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) |
-		(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
+		(tif_need_resched_now() ? TRACE_FLAG_NEED_RESCHED : 0) |
+		(need_resched_lazy() ? TRACE_FLAG_NEED_RESCHED_LAZY : 0) |
 		(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
+
+	entry->migrate_disable = (tsk) ? __migrate_disabled(tsk) & 0xFF : 0;
 }
 EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
 
@@ -3344,14 +3348,17 @@ get_total_entries(struct trace_buffer *b
 
 static void print_lat_help_header(struct seq_file *m)
 {
-	seq_puts(m, "#                  _------=> CPU#            \n"
-		    "#                 / _-----=> irqs-off        \n"
-		    "#                | / _----=> need-resched    \n"
-		    "#                || / _---=> hardirq/softirq \n"
-		    "#                ||| / _--=> preempt-depth   \n"
-		    "#                |||| /     delay            \n"
-		    "#  cmd     pid   ||||| time  |   caller      \n"
-		    "#     \\   /      |||||  \\    |   /         \n");
+	seq_puts(m, "#                  _--------=> CPU#              \n"
+		    "#                 / _-------=> irqs-off          \n"
+		    "#                | / _------=> need-resched      \n"
+		    "#                || / _-----=> need-resched_lazy \n"
+		    "#                ||| / _----=> hardirq/softirq   \n"
+		    "#                |||| / _---=> preempt-depth     \n"
+		    "#                ||||| / _--=> preempt-lazy-depth\n"
+		    "#                |||||| / _-=> migrate-disable   \n"
+		    "#                ||||||| /     delay             \n"
+		    "# cmd     pid    |||||||| time   |  caller       \n"
+		    "#     \\   /      ||||||||   \\    |  /            \n");
 }
 
 static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
@@ -3389,15 +3396,17 @@ static void print_func_help_header_irq(s
 		   tgid ? tgid_space : space);
 	seq_printf(m, "#                          %s / _----=> need-resched\n",
 		   tgid ? tgid_space : space);
-	seq_printf(m, "#                          %s| / _---=> hardirq/softirq\n",
+	seq_printf(m, "#                          %s| / _---=> need-resched_lazy\n",
+		   tgid ? tgid_space : space);
+	seq_printf(m, "#                          %s|| / _--=> hardirq/softirq\n",
 		   tgid ? tgid_space : space);
-	seq_printf(m, "#                          %s|| / _--=> preempt-depth\n",
+	seq_printf(m, "#                          %s||| /     preempt-depth\n",
 		   tgid ? tgid_space : space);
-	seq_printf(m, "#                          %s||| /     delay\n",
+	seq_printf(m, "#                          %s|||| /    delay\n",
 		   tgid ? tgid_space : space);
-	seq_printf(m, "#           TASK-PID %sCPU#  ||||    TIMESTAMP  FUNCTION\n",
+	seq_printf(m, "#           TASK-PID %sCPU#  |||||   TIMESTAMP  FUNCTION\n",
 		   tgid ? "   TGID   " : space);
-	seq_printf(m, "#              | |   %s  |   ||||       |         |\n",
+	seq_printf(m, "#              | |   %s  |   |||||      |         |\n",
 		   tgid ? "     |    " : space);
 }
 
Index: linux-4.19.25-rt16/kernel/trace/trace.h
===================================================================
--- linux-4.19.25-rt16.orig/kernel/trace/trace.h
+++ linux-4.19.25-rt16/kernel/trace/trace.h
@@ -127,6 +127,7 @@ struct kretprobe_trace_entry_head {
  *  NEED_RESCHED	- reschedule is requested
  *  HARDIRQ		- inside an interrupt handler
  *  SOFTIRQ		- inside a softirq handler
+ *  NEED_RESCHED_LAZY	- lazy reschedule is requested
  */
 enum trace_flag_type {
 	TRACE_FLAG_IRQS_OFF		= 0x01,
@@ -136,6 +137,7 @@ enum trace_flag_type {
 	TRACE_FLAG_SOFTIRQ		= 0x10,
 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
 	TRACE_FLAG_NMI			= 0x40,
+	TRACE_FLAG_NEED_RESCHED_LAZY	= 0x80,
 };
 
 #define TRACE_BUF_SIZE		1024
Index: linux-4.19.25-rt16/kernel/trace/trace_events.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/trace/trace_events.c
+++ linux-4.19.25-rt16/kernel/trace/trace_events.c
@@ -188,6 +188,8 @@ static int trace_define_common_fields(vo
 	__common_field(unsigned char, flags);
 	__common_field(unsigned char, preempt_count);
 	__common_field(int, pid);
+	__common_field(unsigned short, migrate_disable);
+	__common_field(unsigned short, padding);
 
 	return ret;
 }
Index: linux-4.19.25-rt16/kernel/trace/trace_hwlat.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/trace/trace_hwlat.c
+++ linux-4.19.25-rt16/kernel/trace/trace_hwlat.c
@@ -277,7 +277,7 @@ static void move_to_next_cpu(void)
 	 * of this thread, than stop migrating for the duration
 	 * of the current test.
 	 */
-	if (!cpumask_equal(current_mask, &current->cpus_allowed))
+	if (!cpumask_equal(current_mask, current->cpus_ptr))
 		goto disable;
 
 	get_online_cpus();
Index: linux-4.19.25-rt16/kernel/trace/trace_output.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/trace/trace_output.c
+++ linux-4.19.25-rt16/kernel/trace/trace_output.c
@@ -448,6 +448,7 @@ int trace_print_lat_fmt(struct trace_seq
 {
 	char hardsoft_irq;
 	char need_resched;
+	char need_resched_lazy;
 	char irqs_off;
 	int hardirq;
 	int softirq;
@@ -478,6 +479,9 @@ int trace_print_lat_fmt(struct trace_seq
 		break;
 	}
 
+	need_resched_lazy =
+		(entry->flags & TRACE_FLAG_NEED_RESCHED_LAZY) ? 'L' : '.';
+
 	hardsoft_irq =
 		(nmi && hardirq)     ? 'Z' :
 		nmi                  ? 'z' :
@@ -486,14 +490,25 @@ int trace_print_lat_fmt(struct trace_seq
 		softirq              ? 's' :
 		                       '.' ;
 
-	trace_seq_printf(s, "%c%c%c",
-			 irqs_off, need_resched, hardsoft_irq);
+	trace_seq_printf(s, "%c%c%c%c",
+			 irqs_off, need_resched, need_resched_lazy,
+			 hardsoft_irq);
 
 	if (entry->preempt_count)
 		trace_seq_printf(s, "%x", entry->preempt_count);
 	else
 		trace_seq_putc(s, '.');
 
+	if (entry->preempt_lazy_count)
+		trace_seq_printf(s, "%x", entry->preempt_lazy_count);
+	else
+		trace_seq_putc(s, '.');
+
+	if (entry->migrate_disable)
+		trace_seq_printf(s, "%x", entry->migrate_disable);
+	else
+		trace_seq_putc(s, '.');
+
 	return !trace_seq_has_overflowed(s);
 }
 
Index: linux-4.19.25-rt16/kernel/watchdog.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/watchdog.c
+++ linux-4.19.25-rt16/kernel/watchdog.c
@@ -483,7 +483,7 @@ static void watchdog_enable(unsigned int
 	 * Start the timer first to prevent the NMI watchdog triggering
 	 * before the timer has a chance to fire.
 	 */
-	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	hrtimer->function = watchdog_timer_fn;
 	hrtimer_start(hrtimer, ns_to_ktime(sample_period),
 		      HRTIMER_MODE_REL_PINNED);
Index: linux-4.19.25-rt16/kernel/watchdog_hld.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/watchdog_hld.c
+++ linux-4.19.25-rt16/kernel/watchdog_hld.c
@@ -24,6 +24,8 @@ static DEFINE_PER_CPU(bool, hard_watchdo
 static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
 static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
 static DEFINE_PER_CPU(struct perf_event *, dead_event);
+static DEFINE_RAW_SPINLOCK(watchdog_output_lock);
+
 static struct cpumask dead_events_mask;
 
 static unsigned long hardlockup_allcpu_dumped;
@@ -134,6 +136,13 @@ static void watchdog_overflow_callback(s
 		/* only print hardlockups once */
 		if (__this_cpu_read(hard_watchdog_warn) == true)
 			return;
+		/*
+		 * If early-printk is enabled then make sure we do not
+		 * lock up in printk() and kill console logging:
+		 */
+		printk_kill();
+
+		raw_spin_lock(&watchdog_output_lock);
 
 		pr_emerg("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
 		print_modules();
@@ -151,6 +160,7 @@ static void watchdog_overflow_callback(s
 				!test_and_set_bit(0, &hardlockup_allcpu_dumped))
 			trigger_allbutself_cpu_backtrace();
 
+		raw_spin_unlock(&watchdog_output_lock);
 		if (hardlockup_panic)
 			nmi_panic(regs, "Hard LOCKUP");
 
Index: linux-4.19.25-rt16/kernel/workqueue.c
===================================================================
--- linux-4.19.25-rt16.orig/kernel/workqueue.c
+++ linux-4.19.25-rt16/kernel/workqueue.c
@@ -49,6 +49,8 @@
 #include <linux/uaccess.h>
 #include <linux/sched/isolation.h>
 #include <linux/nmi.h>
+#include <linux/locallock.h>
+#include <linux/delay.h>
 
 #include "workqueue_internal.h"
 
@@ -123,11 +125,16 @@ enum {
  *    cpu or grabbing pool->lock is enough for read access.  If
  *    POOL_DISASSOCIATED is set, it's identical to L.
  *
+ *    On RT we need the extra protection via rt_lock_idle_list() for
+ *    the list manipulations against read access from
+ *    wq_worker_sleeping(). All other places are nicely serialized via
+ *    pool->lock.
+ *
  * A: wq_pool_attach_mutex protected.
  *
  * PL: wq_pool_mutex protected.
  *
- * PR: wq_pool_mutex protected for writes.  Sched-RCU protected for reads.
+ * PR: wq_pool_mutex protected for writ