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, 133 insertions, 0 deletions

diff --git a/kernel/arch/s390/include/asm/mmu_context.h b/kernel/arch/s390/include/asm/mmu_context.h
new file mode 100644
index 000000000..fb1b93ea3
--- /dev/null
+++ b/kernel/arch/s390/include/asm/mmu_context.h
@@ -0,0 +1,133 @@
+/*
+ *  S390 version
+ *
+ *  Derived from "include/asm-i386/mmu_context.h"
+ */
+
+#ifndef __S390_MMU_CONTEXT_H
+#define __S390_MMU_CONTEXT_H
+
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+#include <asm/tlbflush.h>
+#include <asm/ctl_reg.h>
+
+static inline int init_new_context(struct task_struct *tsk,
+				   struct mm_struct *mm)
+{
+	cpumask_clear(&mm->context.cpu_attach_mask);
+	atomic_set(&mm->context.attach_count, 0);
+	mm->context.flush_mm = 0;
+	mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
+	mm->context.asce_bits |= _ASCE_TYPE_REGION3;
+#ifdef CONFIG_PGSTE
+	mm->context.alloc_pgste = page_table_allocate_pgste;
+	mm->context.has_pgste = 0;
+	mm->context.use_skey = 0;
+#endif
+	mm->context.asce_limit = STACK_TOP_MAX;
+	crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
+	return 0;
+}
+
+#define destroy_context(mm)             do { } while (0)
+
+static inline void set_user_asce(struct mm_struct *mm)
+{
+	S390_lowcore.user_asce = mm->context.asce_bits | __pa(mm->pgd);
+	if (current->thread.mm_segment.ar4)
+		__ctl_load(S390_lowcore.user_asce, 7, 7);
+	set_cpu_flag(CIF_ASCE);
+}
+
+static inline void clear_user_asce(void)
+{
+	S390_lowcore.user_asce = S390_lowcore.kernel_asce;
+
+	__ctl_load(S390_lowcore.user_asce, 1, 1);
+	__ctl_load(S390_lowcore.user_asce, 7, 7);
+}
+
+static inline void load_kernel_asce(void)
+{
+	unsigned long asce;
+
+	__ctl_store(asce, 1, 1);
+	if (asce != S390_lowcore.kernel_asce)
+		__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+	set_cpu_flag(CIF_ASCE);
+}
+
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+			     struct task_struct *tsk)
+{
+	int cpu = smp_processor_id();
+
+	S390_lowcore.user_asce = next->context.asce_bits | __pa(next->pgd);
+	if (prev == next)
+		return;
+	if (MACHINE_HAS_TLB_LC)
+		cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
+	/* Clear old ASCE by loading the kernel ASCE. */
+	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
+	atomic_inc(&next->context.attach_count);
+	atomic_dec(&prev->context.attach_count);
+	if (MACHINE_HAS_TLB_LC)
+		cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
+}
+
+#define finish_arch_post_lock_switch finish_arch_post_lock_switch
+static inline void finish_arch_post_lock_switch(void)
+{
+	struct task_struct *tsk = current;
+	struct mm_struct *mm = tsk->mm;
+
+	load_kernel_asce();
+	if (mm) {
+		preempt_disable();
+		while (atomic_read(&mm->context.attach_count) >> 16)
+			cpu_relax();
+
+		cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
+		if (mm->context.flush_mm)
+			__tlb_flush_mm(mm);
+		preempt_enable();
+	}
+	set_fs(current->thread.mm_segment);
+}
+
+#define enter_lazy_tlb(mm,tsk)	do { } while (0)
+#define deactivate_mm(tsk,mm)	do { } while (0)
+
+static inline void activate_mm(struct mm_struct *prev,
+                               struct mm_struct *next)
+{
+	switch_mm(prev, next, current);
+	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
+	set_user_asce(next);
+}
+
+static inline void arch_dup_mmap(struct mm_struct *oldmm,
+				 struct mm_struct *mm)
+{
+	if (oldmm->context.asce_limit < mm->context.asce_limit)
+		crst_table_downgrade(mm, oldmm->context.asce_limit);
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+}
+
+static inline void arch_unmap(struct mm_struct *mm,
+			struct vm_area_struct *vma,
+			unsigned long start, unsigned long end)
+{
+}
+
+static inline void arch_bprm_mm_init(struct mm_struct *mm,
+				     struct vm_area_struct *vma)
+{
+}
+
+#endif /* __S390_MMU_CONTEXT_H */