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 "linux/sched.h"
  10 #include "um_mmu.h"
  11
  12 extern void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm);
  13 extern void arch_exit_mmap(struct mm_struct *mm);
  14
  15 #define get_mmu_context(task) do ; while(0)
  16 #define activate_context(tsk) do ; while(0)
  17
  18 #define deactivate_mm(tsk,mm)   do { } while (0)
  19
  20 extern void force_flush_all(void);
  21
  22 static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
  23 {
  24         /*
  25          * This is called by fs/exec.c and fs/aio.c. In the first case, for an
  26          * exec, we don't need to do anything as we're called from userspace
  27          * and thus going to use a new host PID. In the second, we're called
  28          * from a kernel thread, and thus need to go doing the mmap's on the
  29          * host. Since they're very expensive, we want to avoid that as far as
  30          * possible.
  31          */
  32         if (old != new && (current->flags & PF_BORROWED_MM))
  33                 __switch_mm(&new->context.id);
  34
  35         arch_dup_mmap(old, new);
  36 }
  37
  38 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  39                              struct task_struct *tsk)
  40 {
  41         unsigned cpu = smp_processor_id();
  42
  43         if(prev != next){
  44                 cpu_clear(cpu, prev->cpu_vm_mask);
  45                 cpu_set(cpu, next->cpu_vm_mask);
  46                 if(next != &init_mm)
  47                         __switch_mm(&next->context.id);
  48         }
  49 }
  50
  51 static inline void enter_lazy_tlb(struct mm_struct *mm,
  52                                   struct task_struct *tsk)
  53 {
  54 }
  55
  56 extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
  57
  58 extern void destroy_context(struct mm_struct *mm);
  59
  60 #endif