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 */ use_mm(struct mm_struct * mm)22void 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 */ unuse_mm(struct mm_struct * mm)53void 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); 65
