include/asm-parisc/mmu_context.h

   1 #ifndef __PARISC_MMU_CONTEXT_H
   2 #define __PARISC_MMU_CONTEXT_H
   3
   4 #include <linux/mm.h>
   5 #include <asm/atomic.h>
   6 #include <asm/pgalloc.h>
   7 #include <asm/pgtable.h>
   8
   9 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
  10 {
  11 }
  12
  13 /* on PA-RISC, we actually have enough contexts to justify an allocator
  14  * for them.  prumpf */
  15
  16 extern unsigned long alloc_sid(void);
  17 extern void free_sid(unsigned long);
  18
  19 static inline int
  20 init_new_context(struct task_struct *tsk, struct mm_struct *mm)
  21 {
  22         BUG_ON(atomic_read(&mm->mm_users) != 1);
  23
  24         mm->context = alloc_sid();
  25         return 0;
  26 }
  27
  28 static inline void
  29 destroy_context(struct mm_struct *mm)
  30 {
  31         free_sid(mm->context);
  32         mm->context = 0;
  33 }
  34
  35 static inline void load_context(mm_context_t context)
  36 {
  37         mtsp(context, 3);
  38 #if SPACEID_SHIFT == 0
  39         mtctl(context << 1,8);
  40 #else
  41         mtctl(context >> (SPACEID_SHIFT - 1),8);
  42 #endif
  43 }
  44
  45 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
  46 {
  47
  48         if (prev != next) {
  49                 mtctl(__pa(next->pgd), 25);
  50                 load_context(next->context);
  51         }
  52 }
  53
  54 #define deactivate_mm(tsk,mm)   do { } while (0)
  55
  56 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  57 {
  58         /*
  59          * Activate_mm is our one chance to allocate a space id
  60          * for a new mm created in the exec path. There's also
  61          * some lazy tlb stuff, which is currently dead code, but
  62          * we only allocate a space id if one hasn't been allocated
  63          * already, so we should be OK.
  64          */
  65
  66         BUG_ON(next == &init_mm); /* Should never happen */
  67
  68         if (next->context == 0)
  69             next->context = alloc_sid();
  70
  71         switch_mm(prev,next,current);
  72 }
  73 #endif