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, 113 insertions, 0 deletions

diff --git a/kernel/arch/powerpc/include/asm/mmu_context.h b/kernel/arch/powerpc/include/asm/mmu_context.h
new file mode 100644
index 000000000..73382eba0
--- /dev/null
+++ b/kernel/arch/powerpc/include/asm/mmu_context.h
@@ -0,0 +1,113 @@
+#ifndef __ASM_POWERPC_MMU_CONTEXT_H
+#define __ASM_POWERPC_MMU_CONTEXT_H
+#ifdef __KERNEL__
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <asm/mmu.h>	
+#include <asm/cputable.h>
+#include <asm-generic/mm_hooks.h>
+#include <asm/cputhreads.h>
+
+/*
+ * Most if the context management is out of line
+ */
+extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
+extern void destroy_context(struct mm_struct *mm);
+
+extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
+extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
+extern void set_context(unsigned long id, pgd_t *pgd);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+extern int __init_new_context(void);
+extern void __destroy_context(int context_id);
+static inline void mmu_context_init(void) { }
+#else
+extern unsigned long __init_new_context(void);
+extern void __destroy_context(unsigned long context_id);
+extern void mmu_context_init(void);
+#endif
+
+extern void switch_cop(struct mm_struct *next);
+extern int use_cop(unsigned long acop, struct mm_struct *mm);
+extern void drop_cop(unsigned long acop, struct mm_struct *mm);
+
+/*
+ * switch_mm is the entry point called from the architecture independent
+ * code in kernel/sched/core.c
+ */
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+			     struct task_struct *tsk)
+{
+	/* Mark this context has been used on the new CPU */
+	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
+
+	/* 32-bit keeps track of the current PGDIR in the thread struct */
+#ifdef CONFIG_PPC32
+	tsk->thread.pgdir = next->pgd;
+#endif /* CONFIG_PPC32 */
+
+	/* 64-bit Book3E keeps track of current PGD in the PACA */
+#ifdef CONFIG_PPC_BOOK3E_64
+	get_paca()->pgd = next->pgd;
+#endif
+	/* Nothing else to do if we aren't actually switching */
+	if (prev == next)
+		return;
+
+#ifdef CONFIG_PPC_ICSWX
+	/* Switch coprocessor context only if prev or next uses a coprocessor */
+	if (prev->context.acop || next->context.acop)
+		switch_cop(next);
+#endif /* CONFIG_PPC_ICSWX */
+
+	/* We must stop all altivec streams before changing the HW
+	 * context
+	 */
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		asm volatile ("dssall");
+#endif /* CONFIG_ALTIVEC */
+
+	/* The actual HW switching method differs between the various
+	 * sub architectures.
+	 */
+#ifdef CONFIG_PPC_STD_MMU_64
+	switch_slb(tsk, next);
+#else
+	/* Out of line for now */
+	switch_mmu_context(prev, next);
+#endif
+
+}
+
+#define deactivate_mm(tsk,mm)	do { } while (0)
+
+/*
+ * After we have set current->mm to a new value, this activates
+ * the context for the new mm so we see the new mappings.
+ */
+static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	switch_mm(prev, next, current);
+	local_irq_restore(flags);
+}
+
+/* We don't currently use enter_lazy_tlb() for anything */
+static inline void enter_lazy_tlb(struct mm_struct *mm,
+				  struct task_struct *tsk)
+{
+	/* 64-bit Book3E keeps track of current PGD in the PACA */
+#ifdef CONFIG_PPC_BOOK3E_64
+	get_paca()->pgd = NULL;
+#endif
+}
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_POWERPC_MMU_CONTEXT_H */