[linux-2.6-block.git] / include / linux / mmu_notifier.h

#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.
	 */
	int (*clear_flush_young)(struct mmu_notifier *mn,
				 struct mm_struct *mm,
				 unsigned long address);

	/*
	 * 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. The subsystem
	 * must guarantee that no additional references are taken to
	 * the pages in the range established between the call to
	 * invalidate_range_start() and the matching call to
	 * invalidate_range_end().
	 *
	 * 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);
};

/*
 * 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_mutex 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 address);
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);

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 address)
{
	if (mm_has_notifiers(mm))
		return __mmu_notifier_clear_flush_young(mm, address);
	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_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);		\
	__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);		\
	__young;							\
})

/*
 * 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 address)
{
	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_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 set_pte_at_notify set_pte_at

#endif /* CONFIG_MMU_NOTIFIER */

#endif /* _LINUX_MMU_NOTIFIER_H */
Commit	Line	Data
cddb8a5c AA	1	#ifndef _LINUX_MMU_NOTIFIER_H
	2	#define _LINUX_MMU_NOTIFIER_H
	3
	4	#include <linux/list.h>
	5	#include <linux/spinlock.h>
	6	#include <linux/mm_types.h>
21a92735	7	#include <linux/srcu.h>
cddb8a5c AA	8
	9	struct mmu_notifier;
	10	struct mmu_notifier_ops;
	11
	12	#ifdef CONFIG_MMU_NOTIFIER
	13
	14	/*
	15	* The mmu notifier_mm structure is allocated and installed in
	16	* mm->mmu_notifier_mm inside the mm_take_all_locks() protected
	17	* critical section and it's released only when mm_count reaches zero
	18	* in mmdrop().
	19	*/
	20	struct mmu_notifier_mm {
	21	/* all mmu notifiers registerd in this mm are queued in this list */
	22	struct hlist_head list;
	23	/* to serialize the list modifications and hlist_unhashed */
	24	spinlock_t lock;
	25	};
	26
	27	struct mmu_notifier_ops {
	28	/*
	29	* Called either by mmu_notifier_unregister or when the mm is
	30	* being destroyed by exit_mmap, always before all pages are
	31	* freed. This can run concurrently with other mmu notifier
	32	* methods (the ones invoked outside the mm context) and it
	33	* should tear down all secondary mmu mappings and freeze the
	34	* secondary mmu. If this method isn't implemented you've to
	35	* be sure that nothing could possibly write to the pages
	36	* through the secondary mmu by the time the last thread with
	37	* tsk->mm == mm exits.
	38	*
	39	* As side note: the pages freed after ->release returns could
	40	* be immediately reallocated by the gart at an alias physical
	41	* address with a different cache model, so if ->release isn't
	42	* implemented because all _software_ driven memory accesses
	43	* through the secondary mmu are terminated by the time the
	44	* last thread of this mm quits, you've also to be sure that
	45	* speculative _hardware_ operations can't allocate dirty
	46	* cachelines in the cpu that could not be snooped and made
	47	* coherent with the other read and write operations happening
	48	* through the gart alias address, so leading to memory
	49	* corruption.
	50	*/
	51	void (release)(struct mmu_notifier mn,
	52	struct mm_struct *mm);
	53
	54	/*
	55	* clear_flush_young is called after the VM is
	56	* test-and-clearing the young/accessed bitflag in the
	57	* pte. This way the VM will provide proper aging to the
	58	* accesses to the page through the secondary MMUs and not
	59	* only to the ones through the Linux pte.
	60	*/
	61	int (clear_flush_young)(struct mmu_notifier mn,
	62	struct mm_struct *mm,
	63	unsigned long address);
	64
8ee53820 AA	65	/*
	66	* test_young is called to check the young/accessed bitflag in
	67	* the secondary pte. This is used to know if the page is
	68	* frequently used without actually clearing the flag or tearing
	69	* down the secondary mapping on the page.
	70	*/
	71	int (test_young)(struct mmu_notifier mn,
	72	struct mm_struct *mm,
	73	unsigned long address);
	74
828502d3 IE	75	/*
	76	* change_pte is called in cases that pte mapping to page is changed:
	77	* for example, when ksm remaps pte to point to a new shared page.
	78	*/
	79	void (change_pte)(struct mmu_notifier mn,
	80	struct mm_struct *mm,
	81	unsigned long address,
	82	pte_t pte);
	83
cddb8a5c AA	84	/*
	85	* Before this is invoked any secondary MMU is still ok to
	86	* read/write to the page previously pointed to by the Linux
	87	* pte because the page hasn't been freed yet and it won't be
	88	* freed until this returns. If required set_page_dirty has to
	89	* be called internally to this method.
	90	*/
	91	void (invalidate_page)(struct mmu_notifier mn,
	92	struct mm_struct *mm,
	93	unsigned long address);
	94
	95	/*
	96	* invalidate_range_start() and invalidate_range_end() must be
	97	* paired and are called only when the mmap_sem and/or the
	98	* locks protecting the reverse maps are held. The subsystem
	99	* must guarantee that no additional references are taken to
	100	* the pages in the range established between the call to
	101	* invalidate_range_start() and the matching call to
	102	* invalidate_range_end().
	103	*
	104	* Invalidation of multiple concurrent ranges may be
	105	* optionally permitted by the driver. Either way the
	106	* establishment of sptes is forbidden in the range passed to
	107	* invalidate_range_begin/end for the whole duration of the
	108	* invalidate_range_begin/end critical section.
	109	*
	110	* invalidate_range_start() is called when all pages in the
	111	* range are still mapped and have at least a refcount of one.
	112	*
	113	* invalidate_range_end() is called when all pages in the
	114	* range have been unmapped and the pages have been freed by
	115	* the VM.
	116	*
	117	* The VM will remove the page table entries and potentially
	118	* the page between invalidate_range_start() and
	119	* invalidate_range_end(). If the page must not be freed
	120	* because of pending I/O or other circumstances then the
	121	* invalidate_range_start() callback (or the initial mapping
	122	* by the driver) must make sure that the refcount is kept
	123	* elevated.
	124	*
	125	* If the driver increases the refcount when the pages are
	126	* initially mapped into an address space then either
	127	* invalidate_range_start() or invalidate_range_end() may
	128	* decrease the refcount. If the refcount is decreased on
	129	* invalidate_range_start() then the VM can free pages as page
	130	* table entries are removed. If the refcount is only
	131	* droppped on invalidate_range_end() then the driver itself
	132	* will drop the last refcount but it must take care to flush
	133	* any secondary tlb before doing the final free on the
	134	* page. Pages will no longer be referenced by the linux
	135	* address space but may still be referenced by sptes until
	136	* the last refcount is dropped.
	137	*/
	138	void (invalidate_range_start)(struct mmu_notifier mn,
	139	struct mm_struct *mm,
	140	unsigned long start, unsigned long end);
	141	void (invalidate_range_end)(struct mmu_notifier mn,
	142	struct mm_struct *mm,
	143	unsigned long start, unsigned long end);
	144	};
	145
	146	/*
	147	* The notifier chains are protected by mmap_sem and/or the reverse map
148	* semaphores. Notifier chains are only changed when all reverse maps and
149	* the mmap_sem locks are taken.
150	*
151	* Therefore notifier chains can only be traversed when either
152	*
153	* 1. mmap_sem is held.
631b0cfd	154	* 2. One of the reverse map locks is held (i_mmap_mutex or anon_vma->rwsem).
cddb8a5c AA	155	* 3. No other concurrent thread can access the list (release)
	156	*/
	157	struct mmu_notifier {
	158	struct hlist_node hlist;
	159	const struct mmu_notifier_ops *ops;
	160	};
	161
	162	static inline int mm_has_notifiers(struct mm_struct *mm)
	163	{
	164	return unlikely(mm->mmu_notifier_mm);
	165	}
	166
	167	extern int mmu_notifier_register(struct mmu_notifier *mn,
	168	struct mm_struct *mm);
	169	extern int __mmu_notifier_register(struct mmu_notifier *mn,
	170	struct mm_struct *mm);
	171	extern void mmu_notifier_unregister(struct mmu_notifier *mn,
	172	struct mm_struct *mm);
b972216e PZ	173	extern void mmu_notifier_unregister_no_release(struct mmu_notifier *mn,
b972216e PZ	174	struct mm_struct *mm);
cddb8a5c AA	175	extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
	176	extern void __mmu_notifier_release(struct mm_struct *mm);
	177	extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
	178	unsigned long address);
8ee53820 AA	179	extern int __mmu_notifier_test_young(struct mm_struct *mm,
8ee53820 AA	180	unsigned long address);
828502d3 IE	181	extern void __mmu_notifier_change_pte(struct mm_struct *mm,
828502d3 IE	182	unsigned long address, pte_t pte);
cddb8a5c AA	183	extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
	184	unsigned long address);
	185	extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
	186	unsigned long start, unsigned long end);
	187	extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
	188	unsigned long start, unsigned long end);
	189
	190	static inline void mmu_notifier_release(struct mm_struct *mm)
	191	{
	192	if (mm_has_notifiers(mm))
	193	__mmu_notifier_release(mm);
	194	}
	195
	196	static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
	197	unsigned long address)
	198	{
	199	if (mm_has_notifiers(mm))
	200	return __mmu_notifier_clear_flush_young(mm, address);
	201	return 0;
	202	}
	203
8ee53820 AA	204	static inline int mmu_notifier_test_young(struct mm_struct *mm,
	205	unsigned long address)
	206	{
	207	if (mm_has_notifiers(mm))
	208	return __mmu_notifier_test_young(mm, address);
	209	return 0;
	210	}
	211
828502d3 IE	212	static inline void mmu_notifier_change_pte(struct mm_struct *mm,
	213	unsigned long address, pte_t pte)
	214	{
	215	if (mm_has_notifiers(mm))
	216	__mmu_notifier_change_pte(mm, address, pte);
	217	}
	218
cddb8a5c AA	219	static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
	220	unsigned long address)
	221	{
	222	if (mm_has_notifiers(mm))
	223	__mmu_notifier_invalidate_page(mm, address);
	224	}
	225
	226	static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
	227	unsigned long start, unsigned long end)
	228	{
	229	if (mm_has_notifiers(mm))
	230	__mmu_notifier_invalidate_range_start(mm, start, end);
	231	}
	232
	233	static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
	234	unsigned long start, unsigned long end)
	235	{
	236	if (mm_has_notifiers(mm))
	237	__mmu_notifier_invalidate_range_end(mm, start, end);
	238	}
	239
	240	static inline void mmu_notifier_mm_init(struct mm_struct *mm)
	241	{
	242	mm->mmu_notifier_mm = NULL;
	243	}
	244
	245	static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
	246	{
	247	if (mm_has_notifiers(mm))
	248	__mmu_notifier_mm_destroy(mm);
	249	}
	250
cddb8a5c AA	251	#define ptep_clear_flush_young_notify(__vma, __address, __ptep) \
	252	({ \
	253	int __young; \
	254	struct vm_area_struct *___vma = __vma; \
	255	unsigned long ___address = __address; \
	256	__young = ptep_clear_flush_young(___vma, ___address, __ptep); \
	257	__young \|= mmu_notifier_clear_flush_young(___vma->vm_mm, \
	258	___address); \
	259	__young; \
	260	})
	261
91a4ee26 AA	262	#define pmdp_clear_flush_young_notify(__vma, __address, __pmdp) \
	263	({ \
	264	int __young; \
	265	struct vm_area_struct *___vma = __vma; \
	266	unsigned long ___address = __address; \
	267	__young = pmdp_clear_flush_young(___vma, ___address, __pmdp); \
	268	__young \|= mmu_notifier_clear_flush_young(___vma->vm_mm, \
	269	___address); \
	270	__young; \
	271	})
	272
48af0d7c XG	273	/*
	274	* set_pte_at_notify() sets the pte _after_ running the notifier.
	275	* This is safe to start by updating the secondary MMUs, because the primary MMU
	276	* pte invalidate must have already happened with a ptep_clear_flush() before
	277	* set_pte_at_notify() has been invoked. Updating the secondary MMUs first is
	278	* required when we change both the protection of the mapping from read-only to
	279	* read-write and the pfn (like during copy on write page faults). Otherwise the
	280	* old page would remain mapped readonly in the secondary MMUs after the new
	281	* page is already writable by some CPU through the primary MMU.
	282	*/
828502d3 IE	283	#define set_pte_at_notify(__mm, __address, __ptep, __pte) \
	284	({ \
	285	struct mm_struct *___mm = __mm; \
	286	unsigned long ___address = __address; \
	287	pte_t ___pte = __pte; \
	288	\
828502d3	289	mmu_notifier_change_pte(___mm, ___address, ___pte); \
48af0d7c	290	set_pte_at(___mm, ___address, __ptep, ___pte); \
828502d3 IE	291	})
828502d3 IE	292
b972216e PZ	293	extern void mmu_notifier_call_srcu(struct rcu_head *rcu,
	294	void (func)(struct rcu_head rcu));
	295	extern void mmu_notifier_synchronize(void);
	296
cddb8a5c AA	297	#else /* CONFIG_MMU_NOTIFIER */
	298
	299	static inline void mmu_notifier_release(struct mm_struct *mm)
	300	{
	301	}
	302
	303	static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
	304	unsigned long address)
8ee53820 AA	305	{
	306	return 0;
	307	}
	308
	309	static inline int mmu_notifier_test_young(struct mm_struct *mm,
	310	unsigned long address)
cddb8a5c AA	311	{
	312	return 0;
	313	}
	314
828502d3 IE	315	static inline void mmu_notifier_change_pte(struct mm_struct *mm,
	316	unsigned long address, pte_t pte)
	317	{
	318	}
	319
cddb8a5c AA	320	static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
	321	unsigned long address)
	322	{
	323	}
	324
	325	static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
	326	unsigned long start, unsigned long end)
	327	{
	328	}
	329
	330	static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
	331	unsigned long start, unsigned long end)
	332	{
	333	}
	334
	335	static inline void mmu_notifier_mm_init(struct mm_struct *mm)
	336	{
	337	}
	338
	339	static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
	340	{
	341	}
	342
	343	#define ptep_clear_flush_young_notify ptep_clear_flush_young
91a4ee26	344	#define pmdp_clear_flush_young_notify pmdp_clear_flush_young
828502d3	345	#define set_pte_at_notify set_pte_at
cddb8a5c AA	346
	347	#endif /* CONFIG_MMU_NOTIFIER */
	348
	349	#endif /* _LINUX_MMU_NOTIFIER_H */