[linux-2.6-block.git] / mm / mmu_context.c

/* Copyright (C) 2009 Red Hat, Inc.
 *
 * See ../COPYING for licensing terms.
 */

#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/sched/task.h>
#include <linux/mmu_context.h>
#include <linux/export.h>

#include <asm/mmu_context.h>

/*
 * use_mm
 *	Makes the calling kernel thread take on the specified
 *	mm context.
 *	(Note: this routine is intended to be called only
 *	from a kernel thread context)
 */
void use_mm(struct mm_struct *mm)
{
	struct mm_struct *active_mm;
	struct task_struct *tsk = current;

	task_lock(tsk);
	active_mm = tsk->active_mm;
	if (active_mm != mm) {
		mmgrab(mm);
		tsk->active_mm = mm;
	}
	tsk->mm = mm;
	switch_mm(active_mm, mm, tsk);
	task_unlock(tsk);
#ifdef finish_arch_post_lock_switch
	finish_arch_post_lock_switch();
#endif

	if (active_mm != mm)
		mmdrop(active_mm);
}
EXPORT_SYMBOL_GPL(use_mm);

/*
 * unuse_mm
 *	Reverses the effect of use_mm, i.e. releases the
 *	specified mm context which was earlier taken on
 *	by the calling kernel thread
 *	(Note: this routine is intended to be called only
 *	from a kernel thread context)
 */
void unuse_mm(struct mm_struct *mm)
{
	struct task_struct *tsk = current;

	task_lock(tsk);
	sync_mm_rss(mm);
	tsk->mm = NULL;
	/* active_mm is still 'mm' */
	enter_lazy_tlb(mm, tsk);
	task_unlock(tsk);
}
EXPORT_SYMBOL_GPL(unuse_mm);
Commit	Line	Data
	1	/* Copyright (C) 2009 Red Hat, Inc.
	2	*
	3	* See ../COPYING for licensing terms.
	4	*/
	5
	6	#include <linux/mm.h>
	7	#include <linux/sched.h>
	8	#include <linux/sched/mm.h>
	9	#include <linux/sched/task.h>
	10	#include <linux/mmu_context.h>
	11	#include <linux/export.h>
	12
	13	#include <asm/mmu_context.h>
	14
	15	/*
	16	* use_mm
	17	* Makes the calling kernel thread take on the specified
	18	* mm context.
	19	* (Note: this routine is intended to be called only
	20	* from a kernel thread context)
	21	*/
	22	void use_mm(struct mm_struct *mm)
	23	{
	24	struct mm_struct *active_mm;
	25	struct task_struct *tsk = current;
	26
	27	task_lock(tsk);
	28	active_mm = tsk->active_mm;
	29	if (active_mm != mm) {
	30	mmgrab(mm);
	31	tsk->active_mm = mm;
	32	}
	33	tsk->mm = mm;
	34	switch_mm(active_mm, mm, tsk);
	35	task_unlock(tsk);
	36	#ifdef finish_arch_post_lock_switch
	37	finish_arch_post_lock_switch();
	38	#endif
	39
	40	if (active_mm != mm)
	41	mmdrop(active_mm);
	42	}
	43	EXPORT_SYMBOL_GPL(use_mm);
	44
	45	/*
	46	* unuse_mm
	47	* Reverses the effect of use_mm, i.e. releases the
	48	* specified mm context which was earlier taken on
	49	* by the calling kernel thread
	50	* (Note: this routine is intended to be called only
	51	* from a kernel thread context)
	52	*/
	53	void unuse_mm(struct mm_struct *mm)
	54	{
	55	struct task_struct *tsk = current;
	56
	57	task_lock(tsk);
	58	sync_mm_rss(mm);
	59	tsk->mm = NULL;
	60	/* active_mm is still 'mm' */
	61	enter_lazy_tlb(mm, tsk);
	62	task_unlock(tsk);
	63	}
	64	EXPORT_SYMBOL_GPL(unuse_mm);