Blame view

kernel/linux-imx6_3.14.28/mm/mmu_context.c 1.21 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
  /* Copyright (C) 2009 Red Hat, Inc.
   *
   * See ../COPYING for licensing terms.
   */
  
  #include <linux/mm.h>
  #include <linux/mmu_context.h>
  #include <linux/export.h>
  #include <linux/sched.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) {
  		atomic_inc(&mm->mm_count);
  		tsk->active_mm = mm;
  	}
  	tsk->mm = mm;
  	switch_mm(active_mm, mm, tsk);
  	task_unlock(tsk);
  
  	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);