include/asm-i386/mmu_context.h

   1 #ifndef __I386_SCHED_H
   2 #define __I386_SCHED_H
   3
   4 #include <asm/desc.h>
   5 #include <asm/atomic.h>
   6 #include <asm/pgalloc.h>
   7 #include <asm/tlbflush.h>
   8 #include <asm/paravirt.h>
   9 #ifndef CONFIG_PARAVIRT
  10 #include <asm-generic/mm_hooks.h>
  11
  12 static inline void paravirt_activate_mm(struct mm_struct *prev,
  13                                         struct mm_struct *next)
  14 {
  15 }
  16 #endif  /* !CONFIG_PARAVIRT */
  17
  18
  19 /*
  20  * Used for LDT copy/destruction.
  21  */
  22 int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
  23 void destroy_context(struct mm_struct *mm);
  24
  25
  26 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
  27 {
  28 #ifdef CONFIG_SMP
  29         unsigned cpu = smp_processor_id();
  30         if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK)
  31                 per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_LAZY;
  32 #endif
  33 }
  34
  35 void leave_mm(unsigned long cpu);
  36
  37 static inline void switch_mm(struct mm_struct *prev,
  38                              struct mm_struct *next,
  39                              struct task_struct *tsk)
  40 {
  41         int cpu = smp_processor_id();
  42
  43         if (likely(prev != next)) {
  44                 /* stop flush ipis for the previous mm */
  45                 cpu_clear(cpu, prev->cpu_vm_mask);
  46 #ifdef CONFIG_SMP
  47                 per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
  48                 per_cpu(cpu_tlbstate, cpu).active_mm = next;
  49 #endif
  50                 cpu_set(cpu, next->cpu_vm_mask);
  51
  52                 /* Re-load page tables */
  53                 load_cr3(next->pgd);
  54
  55                 /*
  56                  * load the LDT, if the LDT is different:
  57                  */
  58                 if (unlikely(prev->context.ldt != next->context.ldt))
  59                         load_LDT_nolock(&next->context);
  60         }
  61 #ifdef CONFIG_SMP
  62         else {
  63                 per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
  64                 BUG_ON(per_cpu(cpu_tlbstate, cpu).active_mm != next);
  65
  66                 if (!cpu_test_and_set(cpu, next->cpu_vm_mask)) {
  67                         /* We were in lazy tlb mode and leave_mm disabled
  68                          * tlb flush IPI delivery. We must reload %cr3.
  69                          */
  70                         load_cr3(next->pgd);
  71                         load_LDT_nolock(&next->context);
  72                 }
  73         }
  74 #endif
  75 }
  76
  77 #define deactivate_mm(tsk, mm)                  \
  78         asm("movl %0,%%gs": :"r" (0));
  79
  80 #define activate_mm(prev, next)                         \
  81         do {                                            \
  82                 paravirt_activate_mm(prev, next);       \
  83                 switch_mm((prev),(next),NULL);          \
  84         } while(0);
  85
  86 #endif