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, 437 insertions, 0 deletions

diff --git a/kernel/include/linux/mmu_notifier.h b/kernel/include/linux/mmu_notifier.h
new file mode 100644
index 000000000..95243d28a
--- /dev/null
+++ b/kernel/include/linux/mmu_notifier.h
@@ -0,0 +1,437 @@
+#ifndef _LINUX_MMU_NOTIFIER_H
+#define _LINUX_MMU_NOTIFIER_H
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/mm_types.h>
+#include <linux/srcu.h>
+
+struct mmu_notifier;
+struct mmu_notifier_ops;
+
+#ifdef CONFIG_MMU_NOTIFIER
+
+/*
+ * The mmu notifier_mm structure is allocated and installed in
+ * mm->mmu_notifier_mm inside the mm_take_all_locks() protected
+ * critical section and it's released only when mm_count reaches zero
+ * in mmdrop().
+ */
+struct mmu_notifier_mm {
+	/* all mmu notifiers registerd in this mm are queued in this list */
+	struct hlist_head list;
+	/* to serialize the list modifications and hlist_unhashed */
+	spinlock_t lock;
+};
+
+struct mmu_notifier_ops {
+	/*
+	 * Called either by mmu_notifier_unregister or when the mm is
+	 * being destroyed by exit_mmap, always before all pages are
+	 * freed. This can run concurrently with other mmu notifier
+	 * methods (the ones invoked outside the mm context) and it
+	 * should tear down all secondary mmu mappings and freeze the
+	 * secondary mmu. If this method isn't implemented you've to
+	 * be sure that nothing could possibly write to the pages
+	 * through the secondary mmu by the time the last thread with
+	 * tsk->mm == mm exits.
+	 *
+	 * As side note: the pages freed after ->release returns could
+	 * be immediately reallocated by the gart at an alias physical
+	 * address with a different cache model, so if ->release isn't
+	 * implemented because all _software_ driven memory accesses
+	 * through the secondary mmu are terminated by the time the
+	 * last thread of this mm quits, you've also to be sure that
+	 * speculative _hardware_ operations can't allocate dirty
+	 * cachelines in the cpu that could not be snooped and made
+	 * coherent with the other read and write operations happening
+	 * through the gart alias address, so leading to memory
+	 * corruption.
+	 */
+	void (*release)(struct mmu_notifier *mn,
+			struct mm_struct *mm);
+
+	/*
+	 * clear_flush_young is called after the VM is
+	 * test-and-clearing the young/accessed bitflag in the
+	 * pte. This way the VM will provide proper aging to the
+	 * accesses to the page through the secondary MMUs and not
+	 * only to the ones through the Linux pte.
+	 * Start-end is necessary in case the secondary MMU is mapping the page
+	 * at a smaller granularity than the primary MMU.
+	 */
+	int (*clear_flush_young)(struct mmu_notifier *mn,
+				 struct mm_struct *mm,
+				 unsigned long start,
+				 unsigned long end);
+
+	/*
+	 * test_young is called to check the young/accessed bitflag in
+	 * the secondary pte. This is used to know if the page is
+	 * frequently used without actually clearing the flag or tearing
+	 * down the secondary mapping on the page.
+	 */
+	int (*test_young)(struct mmu_notifier *mn,
+			  struct mm_struct *mm,
+			  unsigned long address);
+
+	/*
+	 * change_pte is called in cases that pte mapping to page is changed:
+	 * for example, when ksm remaps pte to point to a new shared page.
+	 */
+	void (*change_pte)(struct mmu_notifier *mn,
+			   struct mm_struct *mm,
+			   unsigned long address,
+			   pte_t pte);
+
+	/*
+	 * Before this is invoked any secondary MMU is still ok to
+	 * read/write to the page previously pointed to by the Linux
+	 * pte because the page hasn't been freed yet and it won't be
+	 * freed until this returns. If required set_page_dirty has to
+	 * be called internally to this method.
+	 */
+	void (*invalidate_page)(struct mmu_notifier *mn,
+				struct mm_struct *mm,
+				unsigned long address);
+
+	/*
+	 * invalidate_range_start() and invalidate_range_end() must be
+	 * paired and are called only when the mmap_sem and/or the
+	 * locks protecting the reverse maps are held. If the subsystem
+	 * can't guarantee that no additional references are taken to
+	 * the pages in the range, it has to implement the
+	 * invalidate_range() notifier to remove any references taken
+	 * after invalidate_range_start().
+	 *
+	 * Invalidation of multiple concurrent ranges may be
+	 * optionally permitted by the driver. Either way the
+	 * establishment of sptes is forbidden in the range passed to
+	 * invalidate_range_begin/end for the whole duration of the
+	 * invalidate_range_begin/end critical section.
+	 *
+	 * invalidate_range_start() is called when all pages in the
+	 * range are still mapped and have at least a refcount of one.
+	 *
+	 * invalidate_range_end() is called when all pages in the
+	 * range have been unmapped and the pages have been freed by
+	 * the VM.
+	 *
+	 * The VM will remove the page table entries and potentially
+	 * the page between invalidate_range_start() and
+	 * invalidate_range_end(). If the page must not be freed
+	 * because of pending I/O or other circumstances then the
+	 * invalidate_range_start() callback (or the initial mapping
+	 * by the driver) must make sure that the refcount is kept
+	 * elevated.
+	 *
+	 * If the driver increases the refcount when the pages are
+	 * initially mapped into an address space then either
+	 * invalidate_range_start() or invalidate_range_end() may
+	 * decrease the refcount. If the refcount is decreased on
+	 * invalidate_range_start() then the VM can free pages as page
+	 * table entries are removed.  If the refcount is only
+	 * droppped on invalidate_range_end() then the driver itself
+	 * will drop the last refcount but it must take care to flush
+	 * any secondary tlb before doing the final free on the
+	 * page. Pages will no longer be referenced by the linux
+	 * address space but may still be referenced by sptes until
+	 * the last refcount is dropped.
+	 */
+	void (*invalidate_range_start)(struct mmu_notifier *mn,
+				       struct mm_struct *mm,
+				       unsigned long start, unsigned long end);
+	void (*invalidate_range_end)(struct mmu_notifier *mn,
+				     struct mm_struct *mm,
+				     unsigned long start, unsigned long end);
+
+	/*
+	 * invalidate_range() is either called between
+	 * invalidate_range_start() and invalidate_range_end() when the
+	 * VM has to free pages that where unmapped, but before the
+	 * pages are actually freed, or outside of _start()/_end() when
+	 * a (remote) TLB is necessary.
+	 *
+	 * If invalidate_range() is used to manage a non-CPU TLB with
+	 * shared page-tables, it not necessary to implement the
+	 * invalidate_range_start()/end() notifiers, as
+	 * invalidate_range() alread catches the points in time when an
+	 * external TLB range needs to be flushed.
+	 *
+	 * The invalidate_range() function is called under the ptl
+	 * spin-lock and not allowed to sleep.
+	 *
+	 * Note that this function might be called with just a sub-range
+	 * of what was passed to invalidate_range_start()/end(), if
+	 * called between those functions.
+	 */
+	void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm,
+				 unsigned long start, unsigned long end);
+};
+
+/*
+ * The notifier chains are protected by mmap_sem and/or the reverse map
+ * semaphores. Notifier chains are only changed when all reverse maps and
+ * the mmap_sem locks are taken.
+ *
+ * Therefore notifier chains can only be traversed when either
+ *
+ * 1. mmap_sem is held.
+ * 2. One of the reverse map locks is held (i_mmap_rwsem or anon_vma->rwsem).
+ * 3. No other concurrent thread can access the list (release)
+ */
+struct mmu_notifier {
+	struct hlist_node hlist;
+	const struct mmu_notifier_ops *ops;
+};
+
+static inline int mm_has_notifiers(struct mm_struct *mm)
+{
+	return unlikely(mm->mmu_notifier_mm);
+}
+
+extern int mmu_notifier_register(struct mmu_notifier *mn,
+				 struct mm_struct *mm);
+extern int __mmu_notifier_register(struct mmu_notifier *mn,
+				   struct mm_struct *mm);
+extern void mmu_notifier_unregister(struct mmu_notifier *mn,
+				    struct mm_struct *mm);
+extern void mmu_notifier_unregister_no_release(struct mmu_notifier *mn,
+					       struct mm_struct *mm);
+extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
+extern void __mmu_notifier_release(struct mm_struct *mm);
+extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
+					  unsigned long start,
+					  unsigned long end);
+extern int __mmu_notifier_test_young(struct mm_struct *mm,
+				     unsigned long address);
+extern void __mmu_notifier_change_pte(struct mm_struct *mm,
+				      unsigned long address, pte_t pte);
+extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
+					  unsigned long address);
+extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
+				  unsigned long start, unsigned long end);
+extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
+				  unsigned long start, unsigned long end);
+extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
+				  unsigned long start, unsigned long end);
+
+static inline void mmu_notifier_release(struct mm_struct *mm)
+{
+	if (mm_has_notifiers(mm))
+		__mmu_notifier_release(mm);
+}
+
+static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
+					  unsigned long start,
+					  unsigned long end)
+{
+	if (mm_has_notifiers(mm))
+		return __mmu_notifier_clear_flush_young(mm, start, end);
+	return 0;
+}
+
+static inline int mmu_notifier_test_young(struct mm_struct *mm,
+					  unsigned long address)
+{
+	if (mm_has_notifiers(mm))
+		return __mmu_notifier_test_young(mm, address);
+	return 0;
+}
+
+static inline void mmu_notifier_change_pte(struct mm_struct *mm,
+					   unsigned long address, pte_t pte)
+{
+	if (mm_has_notifiers(mm))
+		__mmu_notifier_change_pte(mm, address, pte);
+}
+
+static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
+					  unsigned long address)
+{
+	if (mm_has_notifiers(mm))
+		__mmu_notifier_invalidate_page(mm, address);
+}
+
+static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
+				  unsigned long start, unsigned long end)
+{
+	if (mm_has_notifiers(mm))
+		__mmu_notifier_invalidate_range_start(mm, start, end);
+}
+
+static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
+				  unsigned long start, unsigned long end)
+{
+	if (mm_has_notifiers(mm))
+		__mmu_notifier_invalidate_range_end(mm, start, end);
+}
+
+static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
+				  unsigned long start, unsigned long end)
+{
+	if (mm_has_notifiers(mm))
+		__mmu_notifier_invalidate_range(mm, start, end);
+}
+
+static inline void mmu_notifier_mm_init(struct mm_struct *mm)
+{
+	mm->mmu_notifier_mm = NULL;
+}
+
+static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
+{
+	if (mm_has_notifiers(mm))
+		__mmu_notifier_mm_destroy(mm);
+}
+
+#define ptep_clear_flush_young_notify(__vma, __address, __ptep)		\
+({									\
+	int __young;							\
+	struct vm_area_struct *___vma = __vma;				\
+	unsigned long ___address = __address;				\
+	__young = ptep_clear_flush_young(___vma, ___address, __ptep);	\
+	__young |= mmu_notifier_clear_flush_young(___vma->vm_mm,	\
+						  ___address,		\
+						  ___address +		\
+							PAGE_SIZE);	\
+	__young;							\
+})
+
+#define pmdp_clear_flush_young_notify(__vma, __address, __pmdp)		\
+({									\
+	int __young;							\
+	struct vm_area_struct *___vma = __vma;				\
+	unsigned long ___address = __address;				\
+	__young = pmdp_clear_flush_young(___vma, ___address, __pmdp);	\
+	__young |= mmu_notifier_clear_flush_young(___vma->vm_mm,	\
+						  ___address,		\
+						  ___address +		\
+							PMD_SIZE);	\
+	__young;							\
+})
+
+#define	ptep_clear_flush_notify(__vma, __address, __ptep)		\
+({									\
+	unsigned long ___addr = __address & PAGE_MASK;			\
+	struct mm_struct *___mm = (__vma)->vm_mm;			\
+	pte_t ___pte;							\
+									\
+	___pte = ptep_clear_flush(__vma, __address, __ptep);		\
+	mmu_notifier_invalidate_range(___mm, ___addr,			\
+					___addr + PAGE_SIZE);		\
+									\
+	___pte;								\
+})
+
+#define pmdp_clear_flush_notify(__vma, __haddr, __pmd)			\
+({									\
+	unsigned long ___haddr = __haddr & HPAGE_PMD_MASK;		\
+	struct mm_struct *___mm = (__vma)->vm_mm;			\
+	pmd_t ___pmd;							\
+									\
+	___pmd = pmdp_clear_flush(__vma, __haddr, __pmd);		\
+	mmu_notifier_invalidate_range(___mm, ___haddr,			\
+				      ___haddr + HPAGE_PMD_SIZE);	\
+									\
+	___pmd;								\
+})
+
+#define pmdp_get_and_clear_notify(__mm, __haddr, __pmd)			\
+({									\
+	unsigned long ___haddr = __haddr & HPAGE_PMD_MASK;		\
+	pmd_t ___pmd;							\
+									\
+	___pmd = pmdp_get_and_clear(__mm, __haddr, __pmd);		\
+	mmu_notifier_invalidate_range(__mm, ___haddr,			\
+				      ___haddr + HPAGE_PMD_SIZE);	\
+									\
+	___pmd;								\
+})
+
+/*
+ * set_pte_at_notify() sets the pte _after_ running the notifier.
+ * This is safe to start by updating the secondary MMUs, because the primary MMU
+ * pte invalidate must have already happened with a ptep_clear_flush() before
+ * set_pte_at_notify() has been invoked.  Updating the secondary MMUs first is
+ * required when we change both the protection of the mapping from read-only to
+ * read-write and the pfn (like during copy on write page faults). Otherwise the
+ * old page would remain mapped readonly in the secondary MMUs after the new
+ * page is already writable by some CPU through the primary MMU.
+ */
+#define set_pte_at_notify(__mm, __address, __ptep, __pte)		\
+({									\
+	struct mm_struct *___mm = __mm;					\
+	unsigned long ___address = __address;				\
+	pte_t ___pte = __pte;						\
+									\
+	mmu_notifier_change_pte(___mm, ___address, ___pte);		\
+	set_pte_at(___mm, ___address, __ptep, ___pte);			\
+})
+
+extern void mmu_notifier_call_srcu(struct rcu_head *rcu,
+				   void (*func)(struct rcu_head *rcu));
+extern void mmu_notifier_synchronize(void);
+
+#else /* CONFIG_MMU_NOTIFIER */
+
+static inline void mmu_notifier_release(struct mm_struct *mm)
+{
+}
+
+static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
+					  unsigned long start,
+					  unsigned long end)
+{
+	return 0;
+}
+
+static inline int mmu_notifier_test_young(struct mm_struct *mm,
+					  unsigned long address)
+{
+	return 0;
+}
+
+static inline void mmu_notifier_change_pte(struct mm_struct *mm,
+					   unsigned long address, pte_t pte)
+{
+}
+
+static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
+					  unsigned long address)
+{
+}
+
+static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
+				  unsigned long start, unsigned long end)
+{
+}
+
+static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
+				  unsigned long start, unsigned long end)
+{
+}
+
+static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
+				  unsigned long start, unsigned long end)
+{
+}
+
+static inline void mmu_notifier_mm_init(struct mm_struct *mm)
+{
+}
+
+static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
+{
+}
+
+#define ptep_clear_flush_young_notify ptep_clear_flush_young
+#define pmdp_clear_flush_young_notify pmdp_clear_flush_young
+#define	ptep_clear_flush_notify ptep_clear_flush
+#define pmdp_clear_flush_notify pmdp_clear_flush
+#define pmdp_get_and_clear_notify pmdp_get_and_clear
+#define set_pte_at_notify set_pte_at
+
+#endif /* CONFIG_MMU_NOTIFIER */
+
+#endif /* _LINUX_MMU_NOTIFIER_H */