include/asm-i386/mmu_context.h

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