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         if (atomic_read(&mm->mm_users) != 1)
  23             BUG();
  24
  25         mm->context = alloc_sid();
  26         return 0;
  27 }
  28
  29 static inline void
  30 destroy_context(struct mm_struct *mm)
  31 {
  32         free_sid(mm->context);
  33         mm->context = 0;
  34 }
  35
  36 static inline void load_context(mm_context_t context)
  37 {
  38         mtsp(context, 3);
  39 #if SPACEID_SHIFT == 0
  40         mtctl(context << 1,8);
  41 #else
  42         mtctl(context >> (SPACEID_SHIFT - 1),8);
  43 #endif
  44 }
  45
  46 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
  47 {
  48
  49         if (prev != next) {
  50                 mtctl(__pa(next->pgd), 25);
  51                 load_context(next->context);
  52         }
  53 }
  54
  55 #define deactivate_mm(tsk,mm)   do { } while (0)
  56
  57 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  58 {
  59         /*
  60          * Activate_mm is our one chance to allocate a space id
  61          * for a new mm created in the exec path. There's also
  62          * some lazy tlb stuff, which is currently dead code, but
  63          * we only allocate a space id if one hasn't been allocated
  64          * already, so we should be OK.
  65          */
  66
  67         if (next == &init_mm) BUG(); /* Should never happen */
  68
  69         if (next->context == 0)
  70             next->context = alloc_sid();
  71
  72         switch_mm(prev,next,current);
  73 }
  74 #endif