include/asm-um/mmu_context.h

   1 /*
   2  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #ifndef __UM_MMU_CONTEXT_H
   7 #define __UM_MMU_CONTEXT_H
   8
   9 #include <asm-generic/mm_hooks.h>
  10
  11 #include "linux/sched.h"
  12 #include "um_mmu.h"
  13
  14 #define get_mmu_context(task) do ; while(0)
  15 #define activate_context(tsk) do ; while(0)
  16
  17 #define deactivate_mm(tsk,mm)   do { } while (0)
  18
  19 extern void force_flush_all(void);
  20
  21 static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
  22 {
  23         /*
  24          * This is called by fs/exec.c and fs/aio.c. In the first case, for an
  25          * exec, we don't need to do anything as we're called from userspace
  26          * and thus going to use a new host PID. In the second, we're called
  27          * from a kernel thread, and thus need to go doing the mmap's on the
  28          * host. Since they're very expensive, we want to avoid that as far as
  29          * possible.
  30          */
  31         if (old != new && (current->flags & PF_BORROWED_MM))
  32                 __switch_mm(&new->context.id);
  33 }
  34
  35 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  36                              struct task_struct *tsk)
  37 {
  38         unsigned cpu = smp_processor_id();
  39
  40         if(prev != next){
  41                 cpu_clear(cpu, prev->cpu_vm_mask);
  42                 cpu_set(cpu, next->cpu_vm_mask);
  43                 if(next != &init_mm)
  44                         __switch_mm(&next->context.id);
  45         }
  46 }
  47
  48 static inline void enter_lazy_tlb(struct mm_struct *mm,
  49                                   struct task_struct *tsk)
  50 {
  51 }
  52
  53 extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
  54
  55 extern void destroy_context(struct mm_struct *mm);
  56
  57 #endif