add realtime linux preempt_rt patch

Enable Kernel options for Realtime, HZ and HighRes Timer
in menuconfig.

5 files changed, 23804 insertions, 11 deletions

diff --git a/target/linux/config/Config.in.addons b/target/linux/config/Config.in.addons
index 1ea6b7315..23ca9b8c1 100644
--- a/target/linux/config/Config.in.addons
+++ b/target/linux/config/Config.in.addons
@@ -3,22 +3,26 @@
 
 config ADK_KERNEL_ADDON_YAFFS2
 	default y if ADK_TARGET_WITH_NAND
-	boolean
+	bool
 
 config ADK_KERNEL_ADDON_GRSEC
-	boolean
+	bool
 	depends on ADK_KERNEL_VERSION_3_14
 
 config ADK_KERNEL_ADDON_MPTCP
-	boolean
+	bool
 	depends on ADK_KERNEL_VERSION_3_14
 
 config ADK_KERNEL_ADDON_FBLOGO
-	boolean
+	bool
 	depends on ADK_KERNEL_VERSION_3_14
 
 config ADK_KERNEL_ADDON_DIETNET
-	boolean
+	bool
 	depends on ADK_KERNEL_VERSION_3_14
 	depends on ADK_KERNEL_VERSION_3_12
 	depends on ADK_KERNEL_VERSION_3_10
+
+config ADK_KERNEL_ADDON_LINUXRT
+	bool
+	depends on ADK_KERNEL_VERSION_3_18
diff --git a/target/linux/config/Config.in.kernel b/target/linux/config/Config.in.kernel
index c6269056f..bba5ac246 100644
--- a/target/linux/config/Config.in.kernel
+++ b/target/linux/config/Config.in.kernel
@@ -227,11 +227,6 @@ config ADK_KERNEL_HIGHMEM
 	help
 	  Enable high memory support.
 
-config ADK_KERNEL_PREEMPT
-	bool "Enable preemptive kernel"
-	help
-	  Enable preemptive mode.
-
 config ADK_KERNEL_BCM2708_DT
 	bool "Enable Devicetree support"
 	depends on ADK_TARGET_SYSTEM_RASPBERRY_PI
@@ -248,6 +243,52 @@ config ADK_KERNEL_CC_OPTIMIZE_FOR_SIZE
 	depends on !ADK_TARGET_ARCH_MICROBLAZE
 	default y
 
+config ADK_KERNEL_PREEMPT
+	bool "Enable preemptive kernel"
+	help
+	  Enable preemptive mode.
+
+config ADK_KERNEL_PREEMPT_RT_FULL
+        bool "Enable Realtime support"
+        select ADK_KERNEL_ADDON_LINUXRT
+        help
+	  https://www.kernel.org/pub/linux/kernel/projects/rt/3.18/
+
+
+choice
+prompt "tick configuration"
+
+config ADK_KERNEL_NO_HZ_IDLE
+	bool "no HZ IDLE, dynamic tick"
+
+config ADK_KERNEL_NO_HZ_FULL
+	bool "no HZ FULL, dynamic tick"
+
+config ADK_KERNEL_HZ_PERIODIC
+	bool "periodic tick"
+
+endchoice
+
+choice
+prompt "HZ"
+depends on ADK_KERNEL_HZ_PERIODIC
+
+config ADK_KERNEL_HZ_100
+	bool "100 HZ"
+
+config ADK_KERNEL_HZ_500
+	bool "500 HZ"
+
+config ADK_KERNEL_HZ_1000
+	bool "1000 HZ"
+
+endchoice
+
+config ADK_KERNEL_HIGH_RES_TIMERS
+	bool "Enable high resolution timers"
+	help
+
+
 choice
 prompt "Page size"
 depends on ADK_TARGET_ARCH_MIPS64
diff --git a/target/linux/kernel.config b/target/linux/kernel.config
index 6ca00150f..e1d0971bc 100644
--- a/target/linux/kernel.config
+++ b/target/linux/kernel.config
@@ -1,7 +1,6 @@
 CONFIG_DEFAULT_HOSTNAME="openadk"
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE=""
-CONFIG_NO_HZ=y
 CONFIG_SYSVIPC=y
 CONFIG_SYSVIPC_SYSCTL=y
 CONFIG_POSIX_MQUEUE=y
diff --git a/target/linux/patches/3.18.8/patch-linuxrt b/target/linux/patches/3.18.8/patch-linuxrt
new file mode 100644
index 000000000..444acdc6c
--- /dev/null
+++ b/target/linux/patches/3.18.8/patch-linuxrt
@@ -0,0 +1,23744 @@
+diff -Nur linux-3.18.8.orig/arch/alpha/mm/fault.c linux-3.18.8/arch/alpha/mm/fault.c
+--- linux-3.18.8.orig/arch/alpha/mm/fault.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/alpha/mm/fault.c	2015-03-03 08:05:17.000000000 +0100
+@@ -107,7 +107,7 @@
+ 
+ 	/* If we're in an interrupt context, or have no user context,
+ 	   we must not take the fault.  */
+-	if (!mm || in_atomic())
++	if (!mm || pagefault_disabled())
+ 		goto no_context;
+ 
+ #ifdef CONFIG_ALPHA_LARGE_VMALLOC
+diff -Nur linux-3.18.8.orig/arch/arm/include/asm/cmpxchg.h linux-3.18.8/arch/arm/include/asm/cmpxchg.h
+--- linux-3.18.8.orig/arch/arm/include/asm/cmpxchg.h	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/include/asm/cmpxchg.h	2015-03-03 08:05:17.000000000 +0100
+@@ -129,6 +129,8 @@
+ 
+ #else	/* min ARCH >= ARMv6 */
+ 
++#define __HAVE_ARCH_CMPXCHG 1
++
+ extern void __bad_cmpxchg(volatile void *ptr, int size);
+ 
+ /*
+diff -Nur linux-3.18.8.orig/arch/arm/include/asm/futex.h linux-3.18.8/arch/arm/include/asm/futex.h
+--- linux-3.18.8.orig/arch/arm/include/asm/futex.h	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/include/asm/futex.h	2015-03-03 08:05:17.000000000 +0100
+@@ -93,6 +93,8 @@
+ 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ 		return -EFAULT;
+ 
++	preempt_disable_rt();
++
+ 	__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
+ 	"1:	" TUSER(ldr) "	%1, [%4]\n"
+ 	"	teq	%1, %2\n"
+@@ -104,6 +106,8 @@
+ 	: "cc", "memory");
+ 
+ 	*uval = val;
++
++	preempt_enable_rt();
+ 	return ret;
+ }
+ 
+diff -Nur linux-3.18.8.orig/arch/arm/include/asm/switch_to.h linux-3.18.8/arch/arm/include/asm/switch_to.h
+--- linux-3.18.8.orig/arch/arm/include/asm/switch_to.h	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/include/asm/switch_to.h	2015-03-03 08:05:17.000000000 +0100
+@@ -3,6 +3,13 @@
+ 
+ #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
+@@ -22,6 +29,7 @@
+ 
+ #define switch_to(prev,next,last)					\
+ do {									\
++	switch_kmaps(prev, next);					\
+ 	last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));	\
+ } while (0)
+ 
+diff -Nur linux-3.18.8.orig/arch/arm/include/asm/thread_info.h linux-3.18.8/arch/arm/include/asm/thread_info.h
+--- linux-3.18.8.orig/arch/arm/include/asm/thread_info.h	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/include/asm/thread_info.h	2015-03-03 08:05:17.000000000 +0100
+@@ -51,6 +51,7 @@
+ 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 */
+ 	struct exec_domain	*exec_domain;	/* execution domain */
+@@ -149,6 +150,7 @@
+ #define TIF_SIGPENDING		0
+ #define TIF_NEED_RESCHED	1
+ #define TIF_NOTIFY_RESUME	2	/* callback before returning to user */
++#define TIF_NEED_RESCHED_LAZY	3
+ #define TIF_UPROBE		7
+ #define TIF_SYSCALL_TRACE	8
+ #define TIF_SYSCALL_AUDIT	9
+@@ -162,6 +164,7 @@
+ #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)
+diff -Nur linux-3.18.8.orig/arch/arm/Kconfig linux-3.18.8/arch/arm/Kconfig
+--- linux-3.18.8.orig/arch/arm/Kconfig	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/Kconfig	2015-03-03 08:05:17.000000000 +0100
+@@ -62,6 +62,7 @@
+ 	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_SYSCALL_TRACEPOINTS
+diff -Nur linux-3.18.8.orig/arch/arm/kernel/asm-offsets.c linux-3.18.8/arch/arm/kernel/asm-offsets.c
+--- linux-3.18.8.orig/arch/arm/kernel/asm-offsets.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/kernel/asm-offsets.c	2015-03-03 08:05:17.000000000 +0100
+@@ -64,6 +64,7 @@
+   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_EXEC_DOMAIN,	offsetof(struct thread_info, exec_domain));
+diff -Nur linux-3.18.8.orig/arch/arm/kernel/entry-armv.S linux-3.18.8/arch/arm/kernel/entry-armv.S
+--- linux-3.18.8.orig/arch/arm/kernel/entry-armv.S	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/kernel/entry-armv.S	2015-03-03 08:05:17.000000000 +0100
+@@ -207,11 +207,18 @@
+ #ifdef CONFIG_PREEMPT
+ 	get_thread_info tsk
+ 	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
+@@ -226,6 +233,8 @@
+ 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
+ #endif
+diff -Nur linux-3.18.8.orig/arch/arm/kernel/process.c linux-3.18.8/arch/arm/kernel/process.c
+--- linux-3.18.8.orig/arch/arm/kernel/process.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/kernel/process.c	2015-03-03 08:05:17.000000000 +0100
+@@ -431,6 +431,30 @@
+ }
+ 
+ #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
+diff -Nur linux-3.18.8.orig/arch/arm/kernel/signal.c linux-3.18.8/arch/arm/kernel/signal.c
+--- linux-3.18.8.orig/arch/arm/kernel/signal.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/kernel/signal.c	2015-03-03 08:05:17.000000000 +0100
+@@ -574,7 +574,8 @@
+ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
+ {
+ 	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)))
+diff -Nur linux-3.18.8.orig/arch/arm/kernel/smp.c linux-3.18.8/arch/arm/kernel/smp.c
+--- linux-3.18.8.orig/arch/arm/kernel/smp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/kernel/smp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -506,12 +506,14 @@
+ }
+ 
+ #ifdef CONFIG_IRQ_WORK
++#ifndef CONFIG_PREEMPT_RT_FULL
+ void arch_irq_work_raise(void)
+ {
+ 	if (arch_irq_work_has_interrupt())
+ 		smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
+ }
+ #endif
++#endif
+ 
+ #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+ void tick_broadcast(const struct cpumask *mask)
+diff -Nur linux-3.18.8.orig/arch/arm/kernel/unwind.c linux-3.18.8/arch/arm/kernel/unwind.c
+--- linux-3.18.8.orig/arch/arm/kernel/unwind.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/kernel/unwind.c	2015-03-03 08:05:17.000000000 +0100
+@@ -93,7 +93,7 @@
+ static const struct unwind_idx *__origin_unwind_idx;
+ extern const struct unwind_idx __stop_unwind_idx[];
+ 
+-static DEFINE_SPINLOCK(unwind_lock);
++static DEFINE_RAW_SPINLOCK(unwind_lock);
+ static LIST_HEAD(unwind_tables);
+ 
+ /* Convert a prel31 symbol to an absolute address */
+@@ -201,7 +201,7 @@
+ 		/* module unwind tables */
+ 		struct unwind_table *table;
+ 
+-		spin_lock_irqsave(&unwind_lock, flags);
++		raw_spin_lock_irqsave(&unwind_lock, flags);
+ 		list_for_each_entry(table, &unwind_tables, list) {
+ 			if (addr >= table->begin_addr &&
+ 			    addr < table->end_addr) {
+@@ -213,7 +213,7 @@
+ 				break;
+ 			}
+ 		}
+-		spin_unlock_irqrestore(&unwind_lock, flags);
++		raw_spin_unlock_irqrestore(&unwind_lock, flags);
+ 	}
+ 
+ 	pr_debug("%s: idx = %p\n", __func__, idx);
+@@ -530,9 +530,9 @@
+ 	tab->begin_addr = text_addr;
+ 	tab->end_addr = text_addr + text_size;
+ 
+-	spin_lock_irqsave(&unwind_lock, flags);
++	raw_spin_lock_irqsave(&unwind_lock, flags);
+ 	list_add_tail(&tab->list, &unwind_tables);
+-	spin_unlock_irqrestore(&unwind_lock, flags);
++	raw_spin_unlock_irqrestore(&unwind_lock, flags);
+ 
+ 	return tab;
+ }
+@@ -544,9 +544,9 @@
+ 	if (!tab)
+ 		return;
+ 
+-	spin_lock_irqsave(&unwind_lock, flags);
++	raw_spin_lock_irqsave(&unwind_lock, flags);
+ 	list_del(&tab->list);
+-	spin_unlock_irqrestore(&unwind_lock, flags);
++	raw_spin_unlock_irqrestore(&unwind_lock, flags);
+ 
+ 	kfree(tab);
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mach-at91/at91rm9200_time.c linux-3.18.8/arch/arm/mach-at91/at91rm9200_time.c
+--- linux-3.18.8.orig/arch/arm/mach-at91/at91rm9200_time.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-at91/at91rm9200_time.c	2015-03-03 08:05:17.000000000 +0100
+@@ -135,6 +135,7 @@
+ 		break;
+ 	case CLOCK_EVT_MODE_SHUTDOWN:
+ 	case CLOCK_EVT_MODE_UNUSED:
++		remove_irq(NR_IRQS_LEGACY + AT91_ID_SYS, &at91rm9200_timer_irq);
+ 	case CLOCK_EVT_MODE_RESUME:
+ 		irqmask = 0;
+ 		break;
+diff -Nur linux-3.18.8.orig/arch/arm/mach-exynos/platsmp.c linux-3.18.8/arch/arm/mach-exynos/platsmp.c
+--- linux-3.18.8.orig/arch/arm/mach-exynos/platsmp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-exynos/platsmp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -137,7 +137,7 @@
+ 	return (void __iomem *)(S5P_VA_SCU);
+ }
+ 
+-static DEFINE_SPINLOCK(boot_lock);
++static DEFINE_RAW_SPINLOCK(boot_lock);
+ 
+ static void exynos_secondary_init(unsigned int cpu)
+ {
+@@ -150,8 +150,8 @@
+ 	/*
+ 	 * 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 exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
+@@ -165,7 +165,7 @@
+ 	 * 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
+@@ -192,7 +192,7 @@
+ 
+ 		if (timeout == 0) {
+ 			printk(KERN_ERR "cpu1 power enable failed");
+-			spin_unlock(&boot_lock);
++			raw_spin_unlock(&boot_lock);
+ 			return -ETIMEDOUT;
+ 		}
+ 	}
+@@ -242,7 +242,7 @@
+ 	 * calibrations, then wait for it to finish
+ 	 */
+ fail:
+-	spin_unlock(&boot_lock);
++	raw_spin_unlock(&boot_lock);
+ 
+ 	return pen_release != -1 ? ret : 0;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mach-hisi/platmcpm.c linux-3.18.8/arch/arm/mach-hisi/platmcpm.c
+--- linux-3.18.8.orig/arch/arm/mach-hisi/platmcpm.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-hisi/platmcpm.c	2015-03-03 08:05:17.000000000 +0100
+@@ -57,7 +57,7 @@
+ 
+ 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
+@@ -104,7 +104,7 @@
+ 	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;
+@@ -133,7 +133,7 @@
+ 	udelay(20);
+ out:
+ 	hip04_cpu_table[cluster][cpu]++;
+-	spin_unlock_irq(&boot_lock);
++	raw_spin_unlock_irq(&boot_lock);
+ 
+ 	return 0;
+ }
+@@ -149,7 +149,7 @@
+ 
+ 	__mcpm_cpu_going_down(cpu, cluster);
+ 
+-	spin_lock(&boot_lock);
++	raw_spin_lock(&boot_lock);
+ 	BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
+ 	hip04_cpu_table[cluster][cpu]--;
+ 	if (hip04_cpu_table[cluster][cpu] == 1) {
+@@ -162,7 +162,7 @@
+ 
+ 	last_man = hip04_cluster_is_down(cluster);
+ 	if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
+-		spin_unlock(&boot_lock);
++		raw_spin_unlock(&boot_lock);
+ 		/* Since it's Cortex A15, disable L2 prefetching. */
+ 		asm volatile(
+ 		"mcr	p15, 1, %0, c15, c0, 3 \n\t"
+@@ -173,7 +173,7 @@
+ 		hip04_set_snoop_filter(cluster, 0);
+ 		__mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
+ 	} else {
+-		spin_unlock(&boot_lock);
++		raw_spin_unlock(&boot_lock);
+ 		v7_exit_coherency_flush(louis);
+ 	}
+ 
+@@ -192,7 +192,7 @@
+ 	       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]) {
+ 			ret = -EBUSY;
+@@ -202,10 +202,10 @@
+ 		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;
+@@ -220,10 +220,10 @@
+ 	}
+ 	if (tries >= count)
+ 		goto err;
+-	spin_unlock_irq(&boot_lock);
++	raw_spin_unlock_irq(&boot_lock);
+ 	return 0;
+ err:
+-	spin_unlock_irq(&boot_lock);
++	raw_spin_unlock_irq(&boot_lock);
+ 	return ret;
+ }
+ 
+@@ -235,10 +235,10 @@
+ 	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+ 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+ 
+-	spin_lock(&boot_lock);
++	raw_spin_lock(&boot_lock);
+ 	if (!hip04_cpu_table[cluster][cpu])
+ 		hip04_cpu_table[cluster][cpu] = 1;
+-	spin_unlock(&boot_lock);
++	raw_spin_unlock(&boot_lock);
+ }
+ 
+ static void __naked hip04_mcpm_power_up_setup(unsigned int affinity_level)
+diff -Nur linux-3.18.8.orig/arch/arm/mach-omap2/omap-smp.c linux-3.18.8/arch/arm/mach-omap2/omap-smp.c
+--- linux-3.18.8.orig/arch/arm/mach-omap2/omap-smp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-omap2/omap-smp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -43,7 +43,7 @@
+ /* SCU base address */
+ static void __iomem *scu_base;
+ 
+-static DEFINE_SPINLOCK(boot_lock);
++static DEFINE_RAW_SPINLOCK(boot_lock);
+ 
+ void __iomem *omap4_get_scu_base(void)
+ {
+@@ -74,8 +74,8 @@
+ 	/*
+ 	 * 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)
+@@ -89,7 +89,7 @@
+ 	 * 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.
+@@ -166,7 +166,7 @@
+ 	 * 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;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mach-prima2/platsmp.c linux-3.18.8/arch/arm/mach-prima2/platsmp.c
+--- linux-3.18.8.orig/arch/arm/mach-prima2/platsmp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-prima2/platsmp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -23,7 +23,7 @@
+ static void __iomem *scu_base;
+ static void __iomem *rsc_base;
+ 
+-static DEFINE_SPINLOCK(boot_lock);
++static DEFINE_RAW_SPINLOCK(boot_lock);
+ 
+ static struct map_desc scu_io_desc __initdata = {
+ 	.length		= SZ_4K,
+@@ -56,8 +56,8 @@
+ 	/*
+ 	 * Synchronise with the boot thread.
+ 	 */
+-	spin_lock(&boot_lock);
+-	spin_unlock(&boot_lock);
++	raw_spin_lock(&boot_lock);
++	raw_spin_unlock(&boot_lock);
+ }
+ 
+ static struct of_device_id rsc_ids[]  = {
+@@ -95,7 +95,7 @@
+ 	/* 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
+@@ -127,7 +127,7 @@
+ 	 * 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;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mach-qcom/platsmp.c linux-3.18.8/arch/arm/mach-qcom/platsmp.c
+--- linux-3.18.8.orig/arch/arm/mach-qcom/platsmp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-qcom/platsmp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -46,7 +46,7 @@
+ 
+ extern void secondary_startup(void);
+ 
+-static DEFINE_SPINLOCK(boot_lock);
++static DEFINE_RAW_SPINLOCK(boot_lock);
+ 
+ #ifdef CONFIG_HOTPLUG_CPU
+ static void __ref qcom_cpu_die(unsigned int cpu)
+@@ -60,8 +60,8 @@
+ 	/*
+ 	 * 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 @@
+ 	 * 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 @@
+ 	 * 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;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mach-spear/platsmp.c linux-3.18.8/arch/arm/mach-spear/platsmp.c
+--- linux-3.18.8.orig/arch/arm/mach-spear/platsmp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-spear/platsmp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -32,7 +32,7 @@
+ 	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 @@
+ 	/*
+ 	 * 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 @@
+ 	 * 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 @@
+ 	 * 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;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mach-sti/platsmp.c linux-3.18.8/arch/arm/mach-sti/platsmp.c
+--- linux-3.18.8.orig/arch/arm/mach-sti/platsmp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-sti/platsmp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -34,7 +34,7 @@
+ 	sync_cache_w(&pen_release);
+ }
+ 
+-static DEFINE_SPINLOCK(boot_lock);
++static DEFINE_RAW_SPINLOCK(boot_lock);
+ 
+ static void sti_secondary_init(unsigned int cpu)
+ {
+@@ -49,8 +49,8 @@
+ 	/*
+ 	 * 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)
+@@ -61,7 +61,7 @@
+ 	 * 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
+@@ -92,7 +92,7 @@
+ 	 * 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;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mach-ux500/platsmp.c linux-3.18.8/arch/arm/mach-ux500/platsmp.c
+--- linux-3.18.8.orig/arch/arm/mach-ux500/platsmp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mach-ux500/platsmp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -51,7 +51,7 @@
+ 	return NULL;
+ }
+ 
+-static DEFINE_SPINLOCK(boot_lock);
++static DEFINE_RAW_SPINLOCK(boot_lock);
+ 
+ static void ux500_secondary_init(unsigned int cpu)
+ {
+@@ -64,8 +64,8 @@
+ 	/*
+ 	 * 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 ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
+@@ -76,7 +76,7 @@
+ 	 * 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
+@@ -97,7 +97,7 @@
+ 	 * 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;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mm/fault.c linux-3.18.8/arch/arm/mm/fault.c
+--- linux-3.18.8.orig/arch/arm/mm/fault.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mm/fault.c	2015-03-03 08:05:17.000000000 +0100
+@@ -277,7 +277,7 @@
+ 	 * If we're in an interrupt or have no user
+ 	 * context, we must not take the fault..
+ 	 */
+-	if (in_atomic() || !mm)
++	if (!mm || pagefault_disabled())
+ 		goto no_context;
+ 
+ 	if (user_mode(regs))
+@@ -431,6 +431,9 @@
+ 	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;
+ 
+@@ -498,6 +501,9 @@
+ 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;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm/mm/highmem.c linux-3.18.8/arch/arm/mm/highmem.c
+--- linux-3.18.8.orig/arch/arm/mm/highmem.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/mm/highmem.c	2015-03-03 08:05:17.000000000 +0100
+@@ -53,6 +53,7 @@
+ 
+ void *kmap_atomic(struct page *page)
+ {
++	pte_t pte = mk_pte(page, kmap_prot);
+ 	unsigned int idx;
+ 	unsigned long vaddr;
+ 	void *kmap;
+@@ -91,7 +92,10 @@
+ 	 * 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;
+ }
+@@ -108,12 +112,15 @@
+ 
+ 		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() */
+@@ -125,6 +132,7 @@
+ 
+ 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);
+@@ -139,7 +147,10 @@
+ #ifdef CONFIG_DEBUG_HIGHMEM
+ 	BUG_ON(!pte_none(*(fixmap_page_table + idx)));
+ #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;
+ }
+@@ -153,3 +164,28 @@
+ 
+ 	return pte_page(get_fixmap_pte(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 = i + KM_TYPE_NR * smp_processor_id();
++
++		set_fixmap_pte(idx, __pte(0));
++	}
++	/*
++	 * 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_fixmap_pte(idx, next_p->kmap_pte[i]);
++	}
++}
++#endif
+diff -Nur linux-3.18.8.orig/arch/arm/plat-versatile/platsmp.c linux-3.18.8/arch/arm/plat-versatile/platsmp.c
+--- linux-3.18.8.orig/arch/arm/plat-versatile/platsmp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm/plat-versatile/platsmp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -30,7 +30,7 @@
+ 	sync_cache_w(&pen_release);
+ }
+ 
+-static DEFINE_SPINLOCK(boot_lock);
++static DEFINE_RAW_SPINLOCK(boot_lock);
+ 
+ void versatile_secondary_init(unsigned int cpu)
+ {
+@@ -43,8 +43,8 @@
+ 	/*
+ 	 * 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)
+@@ -55,7 +55,7 @@
+ 	 * 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
+@@ -85,7 +85,7 @@
+ 	 * 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;
+ }
+diff -Nur linux-3.18.8.orig/arch/arm64/kernel/smp.c linux-3.18.8/arch/arm64/kernel/smp.c
+--- linux-3.18.8.orig/arch/arm64/kernel/smp.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/arm64/kernel/smp.c	2015-03-03 08:05:17.000000000 +0100
+@@ -529,12 +529,14 @@
+ }
+ 
+ #ifdef CONFIG_IRQ_WORK
++#ifndef CONFIG_PREEMPT_RT_FULL
+ void arch_irq_work_raise(void)
+ {
+ 	if (__smp_cross_call)
+ 		smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
+ }
+ #endif
++#endif
+ 
+ static DEFINE_RAW_SPINLOCK(stop_lock);
+ 
+diff -Nur linux-3.18.8.orig/arch/avr32/mm/fault.c linux-3.18.8/arch/avr32/mm/fault.c
+--- linux-3.18.8.orig/arch/avr32/mm/fault.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/avr32/mm/fault.c	2015-03-03 08:05:17.000000000 +0100
+@@ -81,7 +81,7 @@
+ 	 * If we're in an interrupt or have no user context, we must
+ 	 * not take the fault...
+ 	 */
+-	if (in_atomic() || !mm || regs->sr & SYSREG_BIT(GM))
++	if (!mm || regs->sr & SYSREG_BIT(GM) || pagefault_disabled())
+ 		goto no_context;
+ 
+ 	local_irq_enable();
+diff -Nur linux-3.18.8.orig/arch/cris/mm/fault.c linux-3.18.8/arch/cris/mm/fault.c
+--- linux-3.18.8.orig/arch/cris/mm/fault.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/cris/mm/fault.c	2015-03-03 08:05:17.000000000 +0100
+@@ -113,7 +113,7 @@
+ 	 * user context, we must not take the fault.
+ 	 */
+ 
+-	if (in_atomic() || !mm)
++	if (!mm || pagefault_disabled())
+ 		goto no_context;
+ 
+ 	if (user_mode(regs))
+diff -Nur linux-3.18.8.orig/arch/frv/mm/fault.c linux-3.18.8/arch/frv/mm/fault.c
+--- linux-3.18.8.orig/arch/frv/mm/fault.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/frv/mm/fault.c	2015-03-03 08:05:17.000000000 +0100
+@@ -78,7 +78,7 @@
+ 	 * If we're in an interrupt or have no user
+ 	 * context, we must not take the fault..
+ 	 */
+-	if (in_atomic() || !mm)
++	if (!mm || pagefault_disabled())
+ 		goto no_context;
+ 
+ 	if (user_mode(__frame))
+diff -Nur linux-3.18.8.orig/arch/ia64/mm/fault.c linux-3.18.8/arch/ia64/mm/fault.c
+--- linux-3.18.8.orig/arch/ia64/mm/fault.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/ia64/mm/fault.c	2015-03-03 08:05:17.000000000 +0100
+@@ -96,7 +96,7 @@
+ 	/*
+ 	 * If we're in an interrupt or have no user context, we must not take the fault..
+ 	 */
+-	if (in_atomic() || !mm)
++	if (!mm || pagefault_disabled())
+ 		goto no_context;
+ 
+ #ifdef CONFIG_VIRTUAL_MEM_MAP
+diff -Nur linux-3.18.8.orig/arch/Kconfig linux-3.18.8/arch/Kconfig
+--- linux-3.18.8.orig/arch/Kconfig	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/Kconfig	2015-03-03 08:05:17.000000000 +0100
+@@ -6,6 +6,7 @@
+ 	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
+diff -Nur linux-3.18.8.orig/arch/m32r/mm/fault.c linux-3.18.8/arch/m32r/mm/fault.c
+--- linux-3.18.8.orig/arch/m32r/mm/fault.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/m32r/mm/fault.c	2015-03-03 08:05:17.000000000 +0100
+@@ -114,7 +114,7 @@
+ 	 * If we're in an interrupt or have no user context or are running in an
+ 	 * atomic region then we must not take the fault..
+ 	 */
+-	if (in_atomic() || !mm)
++	if (!mm || pagefault_disabled())
+ 		goto bad_area_nosemaphore;
+ 
+ 	if (error_code & ACE_USERMODE)
+diff -Nur linux-3.18.8.orig/arch/m68k/mm/fault.c linux-3.18.8/arch/m68k/mm/fault.c
+--- linux-3.18.8.orig/arch/m68k/mm/fault.c	2015-02-27 02:49:36.000000000 +0100
++++ linux-3.18.8/arch/m68k/mm/fault.c	2015-03-03 08:05:17.0000