[mirror_ubuntu-focal-kernel.git] / include / linux / mmu_notifier.h

/* SPDX-License-Identifier: GPL-2.0 */
#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);

	/*
	 * clear_young is a lightweight version of clear_flush_young. Like the
	 * latter, it is supposed to test-and-clear the young/accessed bitflag
	 * in the secondary pte, but it may omit flushing the secondary tlb.
	 */
	int (*clear_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);

	/*
	 * 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_clear_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_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_clear_young(struct mm_struct *mm,
					   unsigned long start,
					   unsigned long end)
{
	if (mm_has_notifiers(mm))
		return __mmu_notifier_clear_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_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_young_notify(__vma, __address, __ptep)		\
({									\
	int __young;							\
	struct vm_area_struct *___vma = __vma;				\
	unsigned long ___address = __address;				\
	__young = ptep_test_and_clear_young(___vma, ___address, __ptep);\
	__young |= mmu_notifier_clear_young(___vma->vm_mm, ___address,	\
					    ___address + PAGE_SIZE);	\
	__young;							\
})

#define pmdp_clear_young_notify(__vma, __address, __pmdp)		\
({									\
	int __young;							\
	struct vm_area_struct *___vma = __vma;				\
	unsigned long ___address = __address;				\
	__young = pmdp_test_and_clear_young(___vma, ___address, __pmdp);\
	__young |= mmu_notifier_clear_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_huge_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_huge_clear_flush(__vma, __haddr, __pmd);		\
	mmu_notifier_invalidate_range(___mm, ___haddr,			\
				      ___haddr + HPAGE_PMD_SIZE);	\
									\
	___pmd;								\
})

#define pudp_huge_clear_flush_notify(__vma, __haddr, __pud)		\
({									\
	unsigned long ___haddr = __haddr & HPAGE_PUD_MASK;		\
	struct mm_struct *___mm = (__vma)->vm_mm;			\
	pud_t ___pud;							\
									\
	___pud = pudp_huge_clear_flush(__vma, __haddr, __pud);		\
	mmu_notifier_invalidate_range(___mm, ___haddr,			\
				      ___haddr + HPAGE_PUD_SIZE);	\
									\
	___pud;								\
})

/*
 * 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 int mm_has_notifiers(struct mm_struct *mm)
{
	return 0;
}

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_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_young_notify ptep_test_and_clear_young
#define pmdp_clear_young_notify pmdp_test_and_clear_young
#define	ptep_clear_flush_notify ptep_clear_flush
#define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
#define pudp_huge_clear_flush_notify pudp_huge_clear_flush
#define set_pte_at_notify set_pte_at

#endif /* CONFIG_MMU_NOTIFIER */

#endif /* _LINUX_MMU_NOTIFIER_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
cddb8a5c AA	2	#ifndef _LINUX_MMU_NOTIFIER_H
	3	#define _LINUX_MMU_NOTIFIER_H
	4
	5	#include <linux/list.h>
	6	#include <linux/spinlock.h>
	7	#include <linux/mm_types.h>
21a92735	8	#include <linux/srcu.h>
cddb8a5c AA	9
	10	struct mmu_notifier;
	11	struct mmu_notifier_ops;
	12
	13	#ifdef CONFIG_MMU_NOTIFIER
	14
	15	/*
	16	* The mmu notifier_mm structure is allocated and installed in
	17	* mm->mmu_notifier_mm inside the mm_take_all_locks() protected
	18	* critical section and it's released only when mm_count reaches zero
	19	* in mmdrop().
	20	*/
	21	struct mmu_notifier_mm {
	22	/* all mmu notifiers registerd in this mm are queued in this list */
	23	struct hlist_head list;
	24	/* to serialize the list modifications and hlist_unhashed */
	25	spinlock_t lock;
	26	};
	27
	28	struct mmu_notifier_ops {
	29	/*
	30	* Called either by mmu_notifier_unregister or when the mm is
	31	* being destroyed by exit_mmap, always before all pages are
	32	* freed. This can run concurrently with other mmu notifier
	33	* methods (the ones invoked outside the mm context) and it
	34	* should tear down all secondary mmu mappings and freeze the
	35	* secondary mmu. If this method isn't implemented you've to
	36	* be sure that nothing could possibly write to the pages
	37	* through the secondary mmu by the time the last thread with
	38	* tsk->mm == mm exits.
	39	*
	40	* As side note: the pages freed after ->release returns could
	41	* be immediately reallocated by the gart at an alias physical
	42	* address with a different cache model, so if ->release isn't
	43	* implemented because all _software_ driven memory accesses
	44	* through the secondary mmu are terminated by the time the
	45	* last thread of this mm quits, you've also to be sure that
	46	* speculative _hardware_ operations can't allocate dirty
	47	* cachelines in the cpu that could not be snooped and made
	48	* coherent with the other read and write operations happening
	49	* through the gart alias address, so leading to memory
	50	* corruption.
	51	*/
	52	void (release)(struct mmu_notifier mn,
	53	struct mm_struct *mm);
	54
	55	/*
	56	* clear_flush_young is called after the VM is
	57	* test-and-clearing the young/accessed bitflag in the
	58	* pte. This way the VM will provide proper aging to the
	59	* accesses to the page through the secondary MMUs and not
	60	* only to the ones through the Linux pte.
57128468 ALC	61	* Start-end is necessary in case the secondary MMU is mapping the page
57128468 ALC	62	* at a smaller granularity than the primary MMU.
cddb8a5c AA	63	*/
	64	int (clear_flush_young)(struct mmu_notifier mn,
	65	struct mm_struct *mm,
57128468 ALC	66	unsigned long start,
57128468 ALC	67	unsigned long end);
cddb8a5c	68
1d7715c6 VD	69	/*
	70	* clear_young is a lightweight version of clear_flush_young. Like the
	71	* latter, it is supposed to test-and-clear the young/accessed bitflag
	72	* in the secondary pte, but it may omit flushing the secondary tlb.
	73	*/
	74	int (clear_young)(struct mmu_notifier mn,
	75	struct mm_struct *mm,
	76	unsigned long start,
	77	unsigned long end);
	78
8ee53820 AA	79	/*
	80	* test_young is called to check the young/accessed bitflag in
	81	* the secondary pte. This is used to know if the page is
	82	* frequently used without actually clearing the flag or tearing
	83	* down the secondary mapping on the page.
	84	*/
	85	int (test_young)(struct mmu_notifier mn,
	86	struct mm_struct *mm,
	87	unsigned long address);
	88
828502d3 IE	89	/*
	90	* change_pte is called in cases that pte mapping to page is changed:
	91	* for example, when ksm remaps pte to point to a new shared page.
	92	*/
	93	void (change_pte)(struct mmu_notifier mn,
	94	struct mm_struct *mm,
	95	unsigned long address,
	96	pte_t pte);
	97
cddb8a5c AA	98	/*
	99	* invalidate_range_start() and invalidate_range_end() must be
	100	* paired and are called only when the mmap_sem and/or the
0f0a327f JR	101	* locks protecting the reverse maps are held. If the subsystem
	102	* can't guarantee that no additional references are taken to
	103	* the pages in the range, it has to implement the
	104	* invalidate_range() notifier to remove any references taken
	105	* after invalidate_range_start().
cddb8a5c AA	106	*
	107	* Invalidation of multiple concurrent ranges may be
	108	* optionally permitted by the driver. Either way the
	109	* establishment of sptes is forbidden in the range passed to
	110	* invalidate_range_begin/end for the whole duration of the
	111	* invalidate_range_begin/end critical section.
	112	*
	113	* invalidate_range_start() is called when all pages in the
	114	* range are still mapped and have at least a refcount of one.
	115	*
	116	* invalidate_range_end() is called when all pages in the
	117	* range have been unmapped and the pages have been freed by
	118	* the VM.
	119	*
	120	* The VM will remove the page table entries and potentially
	121	* the page between invalidate_range_start() and
	122	* invalidate_range_end(). If the page must not be freed
	123	* because of pending I/O or other circumstances then the
	124	* invalidate_range_start() callback (or the initial mapping
	125	* by the driver) must make sure that the refcount is kept
	126	* elevated.
	127	*
	128	* If the driver increases the refcount when the pages are
	129	* initially mapped into an address space then either
	130	* invalidate_range_start() or invalidate_range_end() may
	131	* decrease the refcount. If the refcount is decreased on
	132	* invalidate_range_start() then the VM can free pages as page
	133	* table entries are removed. If the refcount is only
	134	* droppped on invalidate_range_end() then the driver itself
	135	* will drop the last refcount but it must take care to flush
	136	* any secondary tlb before doing the final free on the
	137	* page. Pages will no longer be referenced by the linux
	138	* address space but may still be referenced by sptes until
	139	* the last refcount is dropped.
	140	*/
	141	void (invalidate_range_start)(struct mmu_notifier mn,
	142	struct mm_struct *mm,
	143	unsigned long start, unsigned long end);
	144	void (invalidate_range_end)(struct mmu_notifier mn,
	145	struct mm_struct *mm,
	146	unsigned long start, unsigned long end);
0f0a327f JR	147
	148	/*
	149	* invalidate_range() is either called between
	150	* invalidate_range_start() and invalidate_range_end() when the
	151	* VM has to free pages that where unmapped, but before the
	152	* pages are actually freed, or outside of _start()/_end() when
	153	* a (remote) TLB is necessary.
	154	*
	155	* If invalidate_range() is used to manage a non-CPU TLB with
	156	* shared page-tables, it not necessary to implement the
	157	* invalidate_range_start()/end() notifiers, as
	158	* invalidate_range() alread catches the points in time when an
	159	* external TLB range needs to be flushed.
	160	*
	161	* The invalidate_range() function is called under the ptl
	162	* spin-lock and not allowed to sleep.
	163	*
	164	* Note that this function might be called with just a sub-range
	165	* of what was passed to invalidate_range_start()/end(), if
	166	* called between those functions.
	167	*/
	168	void (invalidate_range)(struct mmu_notifier mn, struct mm_struct *mm,
	169	unsigned long start, unsigned long end);
cddb8a5c AA	170	};
	171
	172	/*
	173	* The notifier chains are protected by mmap_sem and/or the reverse map
	174	* semaphores. Notifier chains are only changed when all reverse maps and
	175	* the mmap_sem locks are taken.
	176	*
	177	* Therefore notifier chains can only be traversed when either
	178	*
	179	* 1. mmap_sem is held.
c8c06efa	180	* 2. One of the reverse map locks is held (i_mmap_rwsem or anon_vma->rwsem).
cddb8a5c AA	181	* 3. No other concurrent thread can access the list (release)
	182	*/
	183	struct mmu_notifier {
	184	struct hlist_node hlist;
	185	const struct mmu_notifier_ops *ops;
	186	};
	187
	188	static inline int mm_has_notifiers(struct mm_struct *mm)
	189	{
	190	return unlikely(mm->mmu_notifier_mm);
	191	}
	192
	193	extern int mmu_notifier_register(struct mmu_notifier *mn,
	194	struct mm_struct *mm);
	195	extern int __mmu_notifier_register(struct mmu_notifier *mn,
	196	struct mm_struct *mm);
	197	extern void mmu_notifier_unregister(struct mmu_notifier *mn,
	198	struct mm_struct *mm);
b972216e PZ	199	extern void mmu_notifier_unregister_no_release(struct mmu_notifier *mn,
b972216e PZ	200	struct mm_struct *mm);
cddb8a5c AA	201	extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
	202	extern void __mmu_notifier_release(struct mm_struct *mm);
	203	extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
57128468 ALC	204	unsigned long start,
57128468 ALC	205	unsigned long end);
1d7715c6 VD	206	extern int __mmu_notifier_clear_young(struct mm_struct *mm,
	207	unsigned long start,
	208	unsigned long end);
8ee53820 AA	209	extern int __mmu_notifier_test_young(struct mm_struct *mm,
8ee53820 AA	210	unsigned long address);
828502d3 IE	211	extern void __mmu_notifier_change_pte(struct mm_struct *mm,
828502d3 IE	212	unsigned long address, pte_t pte);
cddb8a5c AA	213	extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
	214	unsigned long start, unsigned long end);
	215	extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
	216	unsigned long start, unsigned long end);
0f0a327f JR	217	extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
0f0a327f JR	218	unsigned long start, unsigned long end);
cddb8a5c AA	219
	220	static inline void mmu_notifier_release(struct mm_struct *mm)
	221	{
	222	if (mm_has_notifiers(mm))
	223	__mmu_notifier_release(mm);
	224	}
	225
	226	static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
57128468 ALC	227	unsigned long start,
57128468 ALC	228	unsigned long end)
cddb8a5c AA	229	{
cddb8a5c AA	230	if (mm_has_notifiers(mm))
57128468	231	return __mmu_notifier_clear_flush_young(mm, start, end);
cddb8a5c AA	232	return 0;
	233	}
	234
1d7715c6 VD	235	static inline int mmu_notifier_clear_young(struct mm_struct *mm,
	236	unsigned long start,
	237	unsigned long end)
	238	{
	239	if (mm_has_notifiers(mm))
	240	return __mmu_notifier_clear_young(mm, start, end);
	241	return 0;
	242	}
	243
8ee53820 AA	244	static inline int mmu_notifier_test_young(struct mm_struct *mm,
	245	unsigned long address)
	246	{
	247	if (mm_has_notifiers(mm))
	248	return __mmu_notifier_test_young(mm, address);
	249	return 0;
	250	}
	251
828502d3 IE	252	static inline void mmu_notifier_change_pte(struct mm_struct *mm,
	253	unsigned long address, pte_t pte)
	254	{
	255	if (mm_has_notifiers(mm))
	256	__mmu_notifier_change_pte(mm, address, pte);
	257	}
	258
cddb8a5c AA	259	static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
	260	unsigned long start, unsigned long end)
	261	{
	262	if (mm_has_notifiers(mm))
	263	__mmu_notifier_invalidate_range_start(mm, start, end);
	264	}
	265
	266	static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
	267	unsigned long start, unsigned long end)
	268	{
	269	if (mm_has_notifiers(mm))
	270	__mmu_notifier_invalidate_range_end(mm, start, end);
	271	}
	272
1897bdc4 JR	273	static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
	274	unsigned long start, unsigned long end)
	275	{
0f0a327f JR	276	if (mm_has_notifiers(mm))
0f0a327f JR	277	__mmu_notifier_invalidate_range(mm, start, end);
1897bdc4 JR	278	}
1897bdc4 JR	279
cddb8a5c AA	280	static inline void mmu_notifier_mm_init(struct mm_struct *mm)
	281	{
	282	mm->mmu_notifier_mm = NULL;
	283	}
	284
	285	static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
	286	{
	287	if (mm_has_notifiers(mm))
	288	__mmu_notifier_mm_destroy(mm);
	289	}
	290
cddb8a5c AA	291	#define ptep_clear_flush_young_notify(__vma, __address, __ptep) \
	292	({ \
	293	int __young; \
	294	struct vm_area_struct *___vma = __vma; \
	295	unsigned long ___address = __address; \
	296	__young = ptep_clear_flush_young(___vma, ___address, __ptep); \
	297	__young \|= mmu_notifier_clear_flush_young(___vma->vm_mm, \
57128468 ALC	298	___address, \
	299	___address + \
	300	PAGE_SIZE); \
cddb8a5c AA	301	__young; \
	302	})
	303
91a4ee26 AA	304	#define pmdp_clear_flush_young_notify(__vma, __address, __pmdp) \
	305	({ \
	306	int __young; \
	307	struct vm_area_struct *___vma = __vma; \
	308	unsigned long ___address = __address; \
	309	__young = pmdp_clear_flush_young(___vma, ___address, __pmdp); \
	310	__young \|= mmu_notifier_clear_flush_young(___vma->vm_mm, \
57128468 ALC	311	___address, \
	312	___address + \
	313	PMD_SIZE); \
91a4ee26 AA	314	__young; \
	315	})
	316
1d7715c6 VD	317	#define ptep_clear_young_notify(__vma, __address, __ptep) \
	318	({ \
	319	int __young; \
	320	struct vm_area_struct *___vma = __vma; \
	321	unsigned long ___address = __address; \
	322	__young = ptep_test_and_clear_young(___vma, ___address, __ptep);\
	323	__young \|= mmu_notifier_clear_young(___vma->vm_mm, ___address, \
	324	___address + PAGE_SIZE); \
	325	__young; \
	326	})
	327
	328	#define pmdp_clear_young_notify(__vma, __address, __pmdp) \
	329	({ \
	330	int __young; \
	331	struct vm_area_struct *___vma = __vma; \
	332	unsigned long ___address = __address; \
	333	__young = pmdp_test_and_clear_young(___vma, ___address, __pmdp);\
	334	__young \|= mmu_notifier_clear_young(___vma->vm_mm, ___address, \
	335	___address + PMD_SIZE); \
	336	__young; \
	337	})
	338
34ee645e JR	339	#define ptep_clear_flush_notify(__vma, __address, __ptep) \
	340	({ \
	341	unsigned long ___addr = __address & PAGE_MASK; \
	342	struct mm_struct *___mm = (__vma)->vm_mm; \
	343	pte_t ___pte; \
	344	\
	345	___pte = ptep_clear_flush(__vma, __address, __ptep); \
	346	mmu_notifier_invalidate_range(___mm, ___addr, \
	347	___addr + PAGE_SIZE); \
	348	\
	349	___pte; \
	350	})
	351
8809aa2d	352	#define pmdp_huge_clear_flush_notify(__vma, __haddr, __pmd) \
34ee645e JR	353	({ \
	354	unsigned long ___haddr = __haddr & HPAGE_PMD_MASK; \
	355	struct mm_struct *___mm = (__vma)->vm_mm; \
	356	pmd_t ___pmd; \
	357	\
8809aa2d	358	___pmd = pmdp_huge_clear_flush(__vma, __haddr, __pmd); \
34ee645e JR	359	mmu_notifier_invalidate_range(___mm, ___haddr, \
	360	___haddr + HPAGE_PMD_SIZE); \
	361	\
	362	___pmd; \
	363	})
	364
a00cc7d9 MW	365	#define pudp_huge_clear_flush_notify(__vma, __haddr, __pud) \
	366	({ \
	367	unsigned long ___haddr = __haddr & HPAGE_PUD_MASK; \
	368	struct mm_struct *___mm = (__vma)->vm_mm; \
	369	pud_t ___pud; \
	370	\
	371	___pud = pudp_huge_clear_flush(__vma, __haddr, __pud); \
	372	mmu_notifier_invalidate_range(___mm, ___haddr, \
	373	___haddr + HPAGE_PUD_SIZE); \
	374	\
	375	___pud; \
	376	})
	377
48af0d7c XG	378	/*
	379	* set_pte_at_notify() sets the pte _after_ running the notifier.
	380	* This is safe to start by updating the secondary MMUs, because the primary MMU
	381	* pte invalidate must have already happened with a ptep_clear_flush() before
	382	* set_pte_at_notify() has been invoked. Updating the secondary MMUs first is
	383	* required when we change both the protection of the mapping from read-only to
	384	* read-write and the pfn (like during copy on write page faults). Otherwise the
	385	* old page would remain mapped readonly in the secondary MMUs after the new
	386	* page is already writable by some CPU through the primary MMU.
	387	*/
828502d3 IE	388	#define set_pte_at_notify(__mm, __address, __ptep, __pte) \
	389	({ \
	390	struct mm_struct *___mm = __mm; \
	391	unsigned long ___address = __address; \
	392	pte_t ___pte = __pte; \
	393	\
828502d3	394	mmu_notifier_change_pte(___mm, ___address, ___pte); \
48af0d7c	395	set_pte_at(___mm, ___address, __ptep, ___pte); \
828502d3 IE	396	})
828502d3 IE	397
b972216e PZ	398	extern void mmu_notifier_call_srcu(struct rcu_head *rcu,
	399	void (func)(struct rcu_head rcu));
	400	extern void mmu_notifier_synchronize(void);
	401
cddb8a5c AA	402	#else /* CONFIG_MMU_NOTIFIER */
cddb8a5c AA	403
4d4bbd85 MH	404	static inline int mm_has_notifiers(struct mm_struct *mm)
	405	{
	406	return 0;
	407	}
	408
cddb8a5c AA	409	static inline void mmu_notifier_release(struct mm_struct *mm)
	410	{
	411	}
	412
	413	static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
57128468 ALC	414	unsigned long start,
57128468 ALC	415	unsigned long end)
8ee53820 AA	416	{
	417	return 0;
	418	}
	419
	420	static inline int mmu_notifier_test_young(struct mm_struct *mm,
	421	unsigned long address)
cddb8a5c AA	422	{
	423	return 0;
	424	}
	425
828502d3 IE	426	static inline void mmu_notifier_change_pte(struct mm_struct *mm,
	427	unsigned long address, pte_t pte)
	428	{
	429	}
	430
cddb8a5c AA	431	static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
	432	unsigned long start, unsigned long end)
	433	{
	434	}
	435
	436	static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
	437	unsigned long start, unsigned long end)
	438	{
	439	}
	440
1897bdc4 JR	441	static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
	442	unsigned long start, unsigned long end)
	443	{
	444	}
	445
cddb8a5c AA	446	static inline void mmu_notifier_mm_init(struct mm_struct *mm)
	447	{
	448	}
	449
	450	static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
	451	{
	452	}
	453
	454	#define ptep_clear_flush_young_notify ptep_clear_flush_young
91a4ee26	455	#define pmdp_clear_flush_young_notify pmdp_clear_flush_young
33c3fc71 VD	456	#define ptep_clear_young_notify ptep_test_and_clear_young
33c3fc71 VD	457	#define pmdp_clear_young_notify pmdp_test_and_clear_young
34ee645e	458	#define ptep_clear_flush_notify ptep_clear_flush
8809aa2d	459	#define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
a00cc7d9	460	#define pudp_huge_clear_flush_notify pudp_huge_clear_flush
828502d3	461	#define set_pte_at_notify set_pte_at
cddb8a5c AA	462
	463	#endif /* CONFIG_MMU_NOTIFIER */
	464
	465	#endif /* _LINUX_MMU_NOTIFIER_H */