Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/kernel/arch/arm/include/asm/switch_to.h b/kernel/arch/arm/include/asm/switch_to.h
new file mode 100644
index 000000000..f3e3d800c
--- /dev/null
+++ b/kernel/arch/arm/include/asm/switch_to.h
@@ -0,0 +1,36 @@
+#ifndef __ASM_ARM_SWITCH_TO_H
+#define __ASM_ARM_SWITCH_TO_H
+
+#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
+ * to ensure that the maintenance completes in case we migrate to another
+ * CPU.
+ */
+#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7)
+#define finish_arch_switch(prev)	dsb(ish)
+#endif
+
+/*
+ * switch_to(prev, next) should switch from task `prev' to `next'
+ * `prev' will never be the same as `next'.  schedule() itself
+ * contains the memory barrier to tell GCC not to cache `current'.
+ */
+extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
+
+#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)
+
+#endif /* __ASM_ARM_SWITCH_TO_H */