include/asm-parisc/mmu_context.h

   1 #ifndef __PARISC_MMU_CONTEXT_H
   2 #define __PARISC_MMU_CONTEXT_H
   3
   4 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk, unsigned cpu)
   5 {
   6 }
   7
   8 /* on PA-RISC, we actually have enough contexts to justify an allocator
   9  * for them.  prumpf */
  10
  11 extern unsigned long alloc_sid(void);
  12 extern void free_sid(unsigned long);
  13
  14 static inline int
  15 init_new_context(struct task_struct *tsk, struct mm_struct *mm)
  16 {
  17         /*
  18          * Init_new_context can be called for a cloned mm, so we
  19          * only allocate a space id if one hasn't been allocated
  20          * yet AND mm != &init_mm (cloned kernel thread which
  21          * will run in the kernel space with spaceid 0).
  22          */
  23
  24         if ((mm != &init_mm) && (mm->context == 0)) {
  25                 mm->context = alloc_sid();
  26         }
  27
  28         return 0;
  29 }
  30
  31 static inline void
  32 destroy_context(struct mm_struct *mm)
  33 {
  34         free_sid(mm->context);
  35         mm->context = 0;
  36 }
  37
  38 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk, unsigned cpu)
  39 {
  40
  41         if (prev != next) {
  42                 /* Re-load page tables */
  43                 tsk->thread.pg_tables = __pa(next->pgd);
  44
  45                 mtctl(tsk->thread.pg_tables, 25);
  46                 mtsp(next->context,3);
  47         }
  48 }
  49
  50 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  51 {
  52         /*
  53          * Activate_mm is our one chance to allocate a space id
  54          * for a new mm created in the exec path. There's also
  55          * some lazy tlb stuff, which is currently dead code, but
  56          * we only allocate a space id if one hasn't been allocated
  57          * already, so we should be OK.
  58          */
  59
  60         if (next == &init_mm) BUG(); /* Should never happen */
  61
  62         if (next->context == 0)
  63             next->context = alloc_sid();
  64
  65         switch_mm(prev,next,current,0);
  66 }
  67 #endif