[thirdparty/kernel/stable.git] / include / linux / sched / mm.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SCHED_MM_H
#define _LINUX_SCHED_MM_H

#include <linux/kernel.h>
#include <linux/atomic.h>
#include <linux/sched.h>
#include <linux/mm_types.h>
#include <linux/gfp.h>
#include <linux/sync_core.h>

/*
 * Routines for handling mm_structs
 */
extern struct mm_struct *mm_alloc(void);

/**
 * mmgrab() - Pin a &struct mm_struct.
 * @mm: The &struct mm_struct to pin.
 *
 * Make sure that @mm will not get freed even after the owning task
 * exits. This doesn't guarantee that the associated address space
 * will still exist later on and mmget_not_zero() has to be used before
 * accessing it.
 *
 * This is a preferred way to to pin @mm for a longer/unbounded amount
 * of time.
 *
 * Use mmdrop() to release the reference acquired by mmgrab().
 *
 * See also <Documentation/vm/active_mm.rst> for an in-depth explanation
 * of &mm_struct.mm_count vs &mm_struct.mm_users.
 */
static inline void mmgrab(struct mm_struct *mm)
{
	atomic_inc(&mm->mm_count);
}

extern void __mmdrop(struct mm_struct *mm);

static inline void mmdrop(struct mm_struct *mm)
{
	/*
	 * The implicit full barrier implied by atomic_dec_and_test() is
	 * required by the membarrier system call before returning to
	 * user-space, after storing to rq->curr.
	 */
	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
		__mmdrop(mm);
}

/*
 * This has to be called after a get_task_mm()/mmget_not_zero()
 * followed by taking the mmap_sem for writing before modifying the
 * vmas or anything the coredump pretends not to change from under it.
 *
 * It also has to be called when mmgrab() is used in the context of
 * the process, but then the mm_count refcount is transferred outside
 * the context of the process to run down_write() on that pinned mm.
 *
 * NOTE: find_extend_vma() called from GUP context is the only place
 * that can modify the "mm" (notably the vm_start/end) under mmap_sem
 * for reading and outside the context of the process, so it is also
 * the only case that holds the mmap_sem for reading that must call
 * this function. Generally if the mmap_sem is hold for reading
 * there's no need of this check after get_task_mm()/mmget_not_zero().
 *
 * This function can be obsoleted and the check can be removed, after
 * the coredump code will hold the mmap_sem for writing before
 * invoking the ->core_dump methods.
 */
static inline bool mmget_still_valid(struct mm_struct *mm)
{
	return likely(!mm->core_state);
}

/**
 * mmget() - Pin the address space associated with a &struct mm_struct.
 * @mm: The address space to pin.
 *
 * Make sure that the address space of the given &struct mm_struct doesn't
 * go away. This does not protect against parts of the address space being
 * modified or freed, however.
 *
 * Never use this function to pin this address space for an
 * unbounded/indefinite amount of time.
 *
 * Use mmput() to release the reference acquired by mmget().
 *
 * See also <Documentation/vm/active_mm.rst> for an in-depth explanation
 * of &mm_struct.mm_count vs &mm_struct.mm_users.
 */
static inline void mmget(struct mm_struct *mm)
{
	atomic_inc(&mm->mm_users);
}

static inline bool mmget_not_zero(struct mm_struct *mm)
{
	return atomic_inc_not_zero(&mm->mm_users);
}

/* mmput gets rid of the mappings and all user-space */
extern void mmput(struct mm_struct *);
#ifdef CONFIG_MMU
/* same as above but performs the slow path from the async context. Can
 * be called from the atomic context as well
 */
void mmput_async(struct mm_struct *);
#endif

/* Grab a reference to a task's mm, if it is not already going away */
extern struct mm_struct *get_task_mm(struct task_struct *task);
/*
 * Grab a reference to a task's mm, if it is not already going away
 * and ptrace_may_access with the mode parameter passed to it
 * succeeds.
 */
extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
/* Remove the current tasks stale references to the old mm_struct */
extern void mm_release(struct task_struct *, struct mm_struct *);

#ifdef CONFIG_MEMCG
extern void mm_update_next_owner(struct mm_struct *mm);
#else
static inline void mm_update_next_owner(struct mm_struct *mm)
{
}
#endif /* CONFIG_MEMCG */

#ifdef CONFIG_MMU
extern void arch_pick_mmap_layout(struct mm_struct *mm,
				  struct rlimit *rlim_stack);
extern unsigned long
arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
		       unsigned long, unsigned long);
extern unsigned long
arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
			  unsigned long len, unsigned long pgoff,
			  unsigned long flags);
#else
static inline void arch_pick_mmap_layout(struct mm_struct *mm,
					 struct rlimit *rlim_stack) {}
#endif

static inline bool in_vfork(struct task_struct *tsk)
{
	bool ret;

	/*
	 * need RCU to access ->real_parent if CLONE_VM was used along with
	 * CLONE_PARENT.
	 *
	 * We check real_parent->mm == tsk->mm because CLONE_VFORK does not
	 * imply CLONE_VM
	 *
	 * CLONE_VFORK can be used with CLONE_PARENT/CLONE_THREAD and thus
	 * ->real_parent is not necessarily the task doing vfork(), so in
	 * theory we can't rely on task_lock() if we want to dereference it.
	 *
	 * And in this case we can't trust the real_parent->mm == tsk->mm
	 * check, it can be false negative. But we do not care, if init or
	 * another oom-unkillable task does this it should blame itself.
	 */
	rcu_read_lock();
	ret = tsk->vfork_done && tsk->real_parent->mm == tsk->mm;
	rcu_read_unlock();

	return ret;
}

/*
 * Applies per-task gfp context to the given allocation flags.
 * PF_MEMALLOC_NOIO implies GFP_NOIO
 * PF_MEMALLOC_NOFS implies GFP_NOFS
 * PF_MEMALLOC_NOCMA implies no allocation from CMA region.
 */
static inline gfp_t current_gfp_context(gfp_t flags)
{
	if (unlikely(current->flags &
		     (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_NOCMA))) {
		/*
		 * NOIO implies both NOIO and NOFS and it is a weaker context
		 * so always make sure it makes precedence
		 */
		if (current->flags & PF_MEMALLOC_NOIO)
			flags &= ~(__GFP_IO | __GFP_FS);
		else if (current->flags & PF_MEMALLOC_NOFS)
			flags &= ~__GFP_FS;
#ifdef CONFIG_CMA
		if (current->flags & PF_MEMALLOC_NOCMA)
			flags &= ~__GFP_MOVABLE;
#endif
	}
	return flags;
}

#ifdef CONFIG_LOCKDEP
extern void __fs_reclaim_acquire(void);
extern void __fs_reclaim_release(void);
extern void fs_reclaim_acquire(gfp_t gfp_mask);
extern void fs_reclaim_release(gfp_t gfp_mask);
#else
static inline void __fs_reclaim_acquire(void) { }
static inline void __fs_reclaim_release(void) { }
static inline void fs_reclaim_acquire(gfp_t gfp_mask) { }
static inline void fs_reclaim_release(gfp_t gfp_mask) { }
#endif

/**
 * memalloc_noio_save - Marks implicit GFP_NOIO allocation scope.
 *
 * This functions marks the beginning of the GFP_NOIO allocation scope.
 * All further allocations will implicitly drop __GFP_IO flag and so
 * they are safe for the IO critical section from the allocation recursion
 * point of view. Use memalloc_noio_restore to end the scope with flags
 * returned by this function.
 *
 * This function is safe to be used from any context.
 */
static inline unsigned int memalloc_noio_save(void)
{
	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
	current->flags |= PF_MEMALLOC_NOIO;
	return flags;
}

/**
 * memalloc_noio_restore - Ends the implicit GFP_NOIO scope.
 * @flags: Flags to restore.
 *
 * Ends the implicit GFP_NOIO scope started by memalloc_noio_save function.
 * Always make sure that that the given flags is the return value from the
 * pairing memalloc_noio_save call.
 */
static inline void memalloc_noio_restore(unsigned int flags)
{
	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
}

/**
 * memalloc_nofs_save - Marks implicit GFP_NOFS allocation scope.
 *
 * This functions marks the beginning of the GFP_NOFS allocation scope.
 * All further allocations will implicitly drop __GFP_FS flag and so
 * they are safe for the FS critical section from the allocation recursion
 * point of view. Use memalloc_nofs_restore to end the scope with flags
 * returned by this function.
 *
 * This function is safe to be used from any context.
 */
static inline unsigned int memalloc_nofs_save(void)
{
	unsigned int flags = current->flags & PF_MEMALLOC_NOFS;
	current->flags |= PF_MEMALLOC_NOFS;
	return flags;
}

/**
 * memalloc_nofs_restore - Ends the implicit GFP_NOFS scope.
 * @flags: Flags to restore.
 *
 * Ends the implicit GFP_NOFS scope started by memalloc_nofs_save function.
 * Always make sure that that the given flags is the return value from the
 * pairing memalloc_nofs_save call.
 */
static inline void memalloc_nofs_restore(unsigned int flags)
{
	current->flags = (current->flags & ~PF_MEMALLOC_NOFS) | flags;
}

static inline unsigned int memalloc_noreclaim_save(void)
{
	unsigned int flags = current->flags & PF_MEMALLOC;
	current->flags |= PF_MEMALLOC;
	return flags;
}

static inline void memalloc_noreclaim_restore(unsigned int flags)
{
	current->flags = (current->flags & ~PF_MEMALLOC) | flags;
}

#ifdef CONFIG_CMA
static inline unsigned int memalloc_nocma_save(void)
{
	unsigned int flags = current->flags & PF_MEMALLOC_NOCMA;

	current->flags |= PF_MEMALLOC_NOCMA;
	return flags;
}

static inline void memalloc_nocma_restore(unsigned int flags)
{
	current->flags = (current->flags & ~PF_MEMALLOC_NOCMA) | flags;
}
#else
static inline unsigned int memalloc_nocma_save(void)
{
	return 0;
}

static inline void memalloc_nocma_restore(unsigned int flags)
{
}
#endif

#ifdef CONFIG_MEMCG
/**
 * memalloc_use_memcg - Starts the remote memcg charging scope.
 * @memcg: memcg to charge.
 *
 * This function marks the beginning of the remote memcg charging scope. All the
 * __GFP_ACCOUNT allocations till the end of the scope will be charged to the
 * given memcg.
 *
 * NOTE: This function is not nesting safe.
 */
static inline void memalloc_use_memcg(struct mem_cgroup *memcg)
{
	WARN_ON_ONCE(current->active_memcg);
	current->active_memcg = memcg;
}

/**
 * memalloc_unuse_memcg - Ends the remote memcg charging scope.
 *
 * This function marks the end of the remote memcg charging scope started by
 * memalloc_use_memcg().
 */
static inline void memalloc_unuse_memcg(void)
{
	current->active_memcg = NULL;
}
#else
static inline void memalloc_use_memcg(struct mem_cgroup *memcg)
{
}

static inline void memalloc_unuse_memcg(void)
{
}
#endif

#ifdef CONFIG_MEMBARRIER
enum {
	MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY		= (1U << 0),
	MEMBARRIER_STATE_PRIVATE_EXPEDITED			= (1U << 1),
	MEMBARRIER_STATE_GLOBAL_EXPEDITED_READY			= (1U << 2),
	MEMBARRIER_STATE_GLOBAL_EXPEDITED			= (1U << 3),
	MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY	= (1U << 4),
	MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE		= (1U << 5),
};

enum {
	MEMBARRIER_FLAG_SYNC_CORE	= (1U << 0),
};

#ifdef CONFIG_ARCH_HAS_MEMBARRIER_CALLBACKS
#include <asm/membarrier.h>
#endif

static inline void membarrier_mm_sync_core_before_usermode(struct mm_struct *mm)
{
	if (likely(!(atomic_read(&mm->membarrier_state) &
		     MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE)))
		return;
	sync_core_before_usermode();
}

static inline void membarrier_execve(struct task_struct *t)
{
	atomic_set(&t->mm->membarrier_state, 0);
}
#else
#ifdef CONFIG_ARCH_HAS_MEMBARRIER_CALLBACKS
static inline void membarrier_arch_switch_mm(struct mm_struct *prev,
					     struct mm_struct *next,
					     struct task_struct *tsk)
{
}
#endif
static inline void membarrier_execve(struct task_struct *t)
{
}
static inline void membarrier_mm_sync_core_before_usermode(struct mm_struct *mm)
{
}
#endif

#endif /* _LINUX_SCHED_MM_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
6e84f315 IM	2	#ifndef _LINUX_SCHED_MM_H
	3	#define _LINUX_SCHED_MM_H
	4
b8d6d80b IM	5	#include <linux/kernel.h>
b8d6d80b IM	6	#include <linux/atomic.h>
6e84f315	7	#include <linux/sched.h>
589ee628	8	#include <linux/mm_types.h>
fd771233	9	#include <linux/gfp.h>
70216e18	10	#include <linux/sync_core.h>
6e84f315	11
68e21be2 IM	12	/*
	13	* Routines for handling mm_structs
	14	*/
d70f2a14	15	extern struct mm_struct *mm_alloc(void);
68e21be2 IM	16
	17	/**
	18	* mmgrab() - Pin a &struct mm_struct.
	19	* @mm: The &struct mm_struct to pin.
	20	*
	21	* Make sure that @mm will not get freed even after the owning task
	22	* exits. This doesn't guarantee that the associated address space
	23	* will still exist later on and mmget_not_zero() has to be used before
	24	* accessing it.
	25	*
	26	* This is a preferred way to to pin @mm for a longer/unbounded amount
	27	* of time.
	28	*
	29	* Use mmdrop() to release the reference acquired by mmgrab().
	30	*
ad56b738	31	* See also <Documentation/vm/active_mm.rst> for an in-depth explanation
68e21be2 IM	32	* of &mm_struct.mm_count vs &mm_struct.mm_users.
	33	*/
	34	static inline void mmgrab(struct mm_struct *mm)
	35	{
	36	atomic_inc(&mm->mm_count);
	37	}
	38
d34bc48f AM	39	extern void __mmdrop(struct mm_struct *mm);
	40
	41	static inline void mmdrop(struct mm_struct *mm)
	42	{
	43	/*
	44	* The implicit full barrier implied by atomic_dec_and_test() is
	45	* required by the membarrier system call before returning to
	46	* user-space, after storing to rq->curr.
	47	*/
	48	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
	49	__mmdrop(mm);
	50	}
68e21be2	51
04f5866e AA	52	/*
	53	* This has to be called after a get_task_mm()/mmget_not_zero()
	54	* followed by taking the mmap_sem for writing before modifying the
	55	* vmas or anything the coredump pretends not to change from under it.
	56	*
59ea6d06 AA	57	* It also has to be called when mmgrab() is used in the context of
	58	* the process, but then the mm_count refcount is transferred outside
	59	* the context of the process to run down_write() on that pinned mm.
	60	*
04f5866e AA	61	* NOTE: find_extend_vma() called from GUP context is the only place
	62	* that can modify the "mm" (notably the vm_start/end) under mmap_sem
	63	* for reading and outside the context of the process, so it is also
	64	* the only case that holds the mmap_sem for reading that must call
	65	* this function. Generally if the mmap_sem is hold for reading
	66	* there's no need of this check after get_task_mm()/mmget_not_zero().
	67	*
	68	* This function can be obsoleted and the check can be removed, after
	69	* the coredump code will hold the mmap_sem for writing before
	70	* invoking the ->core_dump methods.
	71	*/
	72	static inline bool mmget_still_valid(struct mm_struct *mm)
	73	{
	74	return likely(!mm->core_state);
	75	}
	76
68e21be2 IM	77	/**
	78	* mmget() - Pin the address space associated with a &struct mm_struct.
	79	* @mm: The address space to pin.
	80	*
	81	* Make sure that the address space of the given &struct mm_struct doesn't
	82	* go away. This does not protect against parts of the address space being
	83	* modified or freed, however.
	84	*
	85	* Never use this function to pin this address space for an
	86	* unbounded/indefinite amount of time.
	87	*
	88	* Use mmput() to release the reference acquired by mmget().
	89	*
ad56b738	90	* See also <Documentation/vm/active_mm.rst> for an in-depth explanation
68e21be2 IM	91	* of &mm_struct.mm_count vs &mm_struct.mm_users.
	92	*/
	93	static inline void mmget(struct mm_struct *mm)
	94	{
	95	atomic_inc(&mm->mm_users);
	96	}
	97
	98	static inline bool mmget_not_zero(struct mm_struct *mm)
	99	{
	100	return atomic_inc_not_zero(&mm->mm_users);
	101	}
	102
	103	/* mmput gets rid of the mappings and all user-space */
	104	extern void mmput(struct mm_struct *);
a1b2289c SY	105	#ifdef CONFIG_MMU
	106	/* same as above but performs the slow path from the async context. Can
	107	* be called from the atomic context as well
	108	*/
	109	void mmput_async(struct mm_struct *);
	110	#endif
68e21be2 IM	111
	112	/* Grab a reference to a task's mm, if it is not already going away */
	113	extern struct mm_struct get_task_mm(struct task_struct task);
	114	/*
	115	* Grab a reference to a task's mm, if it is not already going away
	116	* and ptrace_may_access with the mode parameter passed to it
	117	* succeeds.
	118	*/
	119	extern struct mm_struct mm_access(struct task_struct task, unsigned int mode);
	120	/* Remove the current tasks stale references to the old mm_struct */
	121	extern void mm_release(struct task_struct , struct mm_struct );
	122
4240c8bf IM	123	#ifdef CONFIG_MEMCG
	124	extern void mm_update_next_owner(struct mm_struct *mm);
	125	#else
	126	static inline void mm_update_next_owner(struct mm_struct *mm)
	127	{
	128	}
	129	#endif /* CONFIG_MEMCG */
	130
	131	#ifdef CONFIG_MMU
8f2af155 KC	132	extern void arch_pick_mmap_layout(struct mm_struct *mm,
8f2af155 KC	133	struct rlimit *rlim_stack);
4240c8bf IM	134	extern unsigned long
	135	arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
	136	unsigned long, unsigned long);
	137	extern unsigned long
	138	arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
	139	unsigned long len, unsigned long pgoff,
	140	unsigned long flags);
	141	#else
8f2af155 KC	142	static inline void arch_pick_mmap_layout(struct mm_struct *mm,
8f2af155 KC	143	struct rlimit *rlim_stack) {}
4240c8bf IM	144	#endif
4240c8bf IM	145
d026ce79 IM	146	static inline bool in_vfork(struct task_struct *tsk)
	147	{
	148	bool ret;
	149
	150	/*
	151	* need RCU to access ->real_parent if CLONE_VM was used along with
	152	* CLONE_PARENT.
	153	*
	154	* We check real_parent->mm == tsk->mm because CLONE_VFORK does not
	155	* imply CLONE_VM
	156	*
	157	* CLONE_VFORK can be used with CLONE_PARENT/CLONE_THREAD and thus
	158	* ->real_parent is not necessarily the task doing vfork(), so in
	159	* theory we can't rely on task_lock() if we want to dereference it.
	160	*
	161	* And in this case we can't trust the real_parent->mm == tsk->mm
	162	* check, it can be false negative. But we do not care, if init or
	163	* another oom-unkillable task does this it should blame itself.
	164	*/
	165	rcu_read_lock();
	166	ret = tsk->vfork_done && tsk->real_parent->mm == tsk->mm;
	167	rcu_read_unlock();
	168
	169	return ret;
	170	}
	171
7dea19f9 MH	172	/*
	173	* Applies per-task gfp context to the given allocation flags.
	174	* PF_MEMALLOC_NOIO implies GFP_NOIO
	175	* PF_MEMALLOC_NOFS implies GFP_NOFS
d7fefcc8	176	* PF_MEMALLOC_NOCMA implies no allocation from CMA region.
74444eda	177	*/
7dea19f9	178	static inline gfp_t current_gfp_context(gfp_t flags)
74444eda	179	{
d7fefcc8 AK	180	if (unlikely(current->flags &
	181	(PF_MEMALLOC_NOIO \| PF_MEMALLOC_NOFS \| PF_MEMALLOC_NOCMA))) {
	182	/*
	183	* NOIO implies both NOIO and NOFS and it is a weaker context
	184	* so always make sure it makes precedence
	185	*/
	186	if (current->flags & PF_MEMALLOC_NOIO)
	187	flags &= ~(__GFP_IO \| __GFP_FS);
	188	else if (current->flags & PF_MEMALLOC_NOFS)
	189	flags &= ~__GFP_FS;
	190	#ifdef CONFIG_CMA
	191	if (current->flags & PF_MEMALLOC_NOCMA)
	192	flags &= ~__GFP_MOVABLE;
	193	#endif
	194	}
74444eda IM	195	return flags;
	196	}
	197
d92a8cfc	198	#ifdef CONFIG_LOCKDEP
93781325 OS	199	extern void __fs_reclaim_acquire(void);
93781325 OS	200	extern void __fs_reclaim_release(void);
d92a8cfc PZ	201	extern void fs_reclaim_acquire(gfp_t gfp_mask);
	202	extern void fs_reclaim_release(gfp_t gfp_mask);
	203	#else
93781325 OS	204	static inline void __fs_reclaim_acquire(void) { }
93781325 OS	205	static inline void __fs_reclaim_release(void) { }
d92a8cfc PZ	206	static inline void fs_reclaim_acquire(gfp_t gfp_mask) { }
	207	static inline void fs_reclaim_release(gfp_t gfp_mask) { }
	208	#endif
	209
46ca3599 MH	210	/**
	211	* memalloc_noio_save - Marks implicit GFP_NOIO allocation scope.
	212	*
	213	* This functions marks the beginning of the GFP_NOIO allocation scope.
	214	* All further allocations will implicitly drop __GFP_IO flag and so
	215	* they are safe for the IO critical section from the allocation recursion
	216	* point of view. Use memalloc_noio_restore to end the scope with flags
	217	* returned by this function.
	218	*
	219	* This function is safe to be used from any context.
	220	*/
74444eda IM	221	static inline unsigned int memalloc_noio_save(void)
	222	{
	223	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
	224	current->flags \|= PF_MEMALLOC_NOIO;
	225	return flags;
	226	}
	227
46ca3599 MH	228	/**
	229	* memalloc_noio_restore - Ends the implicit GFP_NOIO scope.
	230	* @flags: Flags to restore.
	231	*
	232	* Ends the implicit GFP_NOIO scope started by memalloc_noio_save function.
	233	* Always make sure that that the given flags is the return value from the
	234	* pairing memalloc_noio_save call.
	235	*/
74444eda IM	236	static inline void memalloc_noio_restore(unsigned int flags)
	237	{
	238	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) \| flags;
	239	}
	240
46ca3599 MH	241	/**
	242	* memalloc_nofs_save - Marks implicit GFP_NOFS allocation scope.
	243	*
	244	* This functions marks the beginning of the GFP_NOFS allocation scope.
	245	* All further allocations will implicitly drop __GFP_FS flag and so
	246	* they are safe for the FS critical section from the allocation recursion
	247	* point of view. Use memalloc_nofs_restore to end the scope with flags
	248	* returned by this function.
	249	*
	250	* This function is safe to be used from any context.
	251	*/
7dea19f9 MH	252	static inline unsigned int memalloc_nofs_save(void)
	253	{
	254	unsigned int flags = current->flags & PF_MEMALLOC_NOFS;
	255	current->flags \|= PF_MEMALLOC_NOFS;
	256	return flags;
	257	}
	258
46ca3599 MH	259	/**
	260	* memalloc_nofs_restore - Ends the implicit GFP_NOFS scope.
	261	* @flags: Flags to restore.
	262	*
	263	* Ends the implicit GFP_NOFS scope started by memalloc_nofs_save function.
	264	* Always make sure that that the given flags is the return value from the
	265	* pairing memalloc_nofs_save call.
	266	*/
7dea19f9 MH	267	static inline void memalloc_nofs_restore(unsigned int flags)
	268	{
	269	current->flags = (current->flags & ~PF_MEMALLOC_NOFS) \| flags;
	270	}
	271
499118e9 VB	272	static inline unsigned int memalloc_noreclaim_save(void)
	273	{
	274	unsigned int flags = current->flags & PF_MEMALLOC;
	275	current->flags \|= PF_MEMALLOC;
	276	return flags;
	277	}
	278
	279	static inline void memalloc_noreclaim_restore(unsigned int flags)
	280	{
	281	current->flags = (current->flags & ~PF_MEMALLOC) \| flags;
	282	}
	283
d7fefcc8 AK	284	#ifdef CONFIG_CMA
	285	static inline unsigned int memalloc_nocma_save(void)
	286	{
	287	unsigned int flags = current->flags & PF_MEMALLOC_NOCMA;
	288
	289	current->flags \|= PF_MEMALLOC_NOCMA;
	290	return flags;
	291	}
	292
	293	static inline void memalloc_nocma_restore(unsigned int flags)
	294	{
	295	current->flags = (current->flags & ~PF_MEMALLOC_NOCMA) \| flags;
	296	}
	297	#else
	298	static inline unsigned int memalloc_nocma_save(void)
	299	{
	300	return 0;
	301	}
	302
	303	static inline void memalloc_nocma_restore(unsigned int flags)
	304	{
	305	}
	306	#endif
	307
d46eb14b SB	308	#ifdef CONFIG_MEMCG
	309	/**
	310	* memalloc_use_memcg - Starts the remote memcg charging scope.
	311	* @memcg: memcg to charge.
	312	*
	313	* This function marks the beginning of the remote memcg charging scope. All the
	314	* __GFP_ACCOUNT allocations till the end of the scope will be charged to the
	315	* given memcg.
	316	*
	317	* NOTE: This function is not nesting safe.
	318	*/
	319	static inline void memalloc_use_memcg(struct mem_cgroup *memcg)
	320	{
	321	WARN_ON_ONCE(current->active_memcg);
	322	current->active_memcg = memcg;
	323	}
	324
	325	/**
	326	* memalloc_unuse_memcg - Ends the remote memcg charging scope.
	327	*
	328	* This function marks the end of the remote memcg charging scope started by
	329	* memalloc_use_memcg().
	330	*/
	331	static inline void memalloc_unuse_memcg(void)
	332	{
	333	current->active_memcg = NULL;
	334	}
	335	#else
	336	static inline void memalloc_use_memcg(struct mem_cgroup *memcg)
	337	{
	338	}
	339
	340	static inline void memalloc_unuse_memcg(void)
	341	{
	342	}
	343	#endif
	344
a961e409 MD	345	#ifdef CONFIG_MEMBARRIER
a961e409 MD	346	enum {
c5f58bd5 MD	347	MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY = (1U << 0),
	348	MEMBARRIER_STATE_PRIVATE_EXPEDITED = (1U << 1),
	349	MEMBARRIER_STATE_GLOBAL_EXPEDITED_READY = (1U << 2),
	350	MEMBARRIER_STATE_GLOBAL_EXPEDITED = (1U << 3),
70216e18 MD	351	MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY = (1U << 4),
	352	MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE = (1U << 5),
	353	};
	354
	355	enum {
	356	MEMBARRIER_FLAG_SYNC_CORE = (1U << 0),
a961e409 MD	357	};
a961e409 MD	358
3ccfebed MD	359	#ifdef CONFIG_ARCH_HAS_MEMBARRIER_CALLBACKS
	360	#include <asm/membarrier.h>
	361	#endif
	362
70216e18 MD	363	static inline void membarrier_mm_sync_core_before_usermode(struct mm_struct *mm)
	364	{
	365	if (likely(!(atomic_read(&mm->membarrier_state) &
	366	MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE)))
	367	return;
	368	sync_core_before_usermode();
	369	}
	370
a961e409 MD	371	static inline void membarrier_execve(struct task_struct *t)
	372	{
	373	atomic_set(&t->mm->membarrier_state, 0);
	374	}
	375	#else
3ccfebed MD	376	#ifdef CONFIG_ARCH_HAS_MEMBARRIER_CALLBACKS
	377	static inline void membarrier_arch_switch_mm(struct mm_struct *prev,
	378	struct mm_struct *next,
	379	struct task_struct *tsk)
	380	{
	381	}
	382	#endif
a961e409 MD	383	static inline void membarrier_execve(struct task_struct *t)
	384	{
	385	}
70216e18 MD	386	static inline void membarrier_mm_sync_core_before_usermode(struct mm_struct *mm)
	387	{
	388	}
a961e409 MD	389	#endif
a961e409 MD	390
6e84f315	391	#endif /* _LINUX_SCHED_MM_H */