include/asm-s390/mmu_context.h

   1 /*
   2  *  include/asm-s390/mmu_context.h
   3  *
   4  *  S390 version
   5  *
   6  *  Derived from "include/asm-i386/mmu_context.h"
   7  */
   8
   9 #ifndef __S390_MMU_CONTEXT_H
  10 #define __S390_MMU_CONTEXT_H
  11
  12 #include <asm/pgalloc.h>
  13 #include <asm-generic/mm_hooks.h>
  14
  15 static inline int init_new_context(struct task_struct *tsk,
  16                                    struct mm_struct *mm)
  17 {
  18         mm->context = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
  19 #ifdef CONFIG_64BIT
  20         mm->context |= _ASCE_TYPE_REGION3;
  21 #endif
  22         return 0;
  23 }
  24
  25 #define destroy_context(mm)             do { } while (0)
  26
  27 #ifndef __s390x__
  28 #define LCTL_OPCODE "lctl"
  29 #else
  30 #define LCTL_OPCODE "lctlg"
  31 #endif
  32
  33 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
  34 {
  35         S390_lowcore.user_asce = mm->context | __pa(mm->pgd);
  36         if (switch_amode) {
  37                 /* Load primary space page table origin. */
  38                 pgd_t *shadow_pgd = get_shadow_table(mm->pgd) ? : mm->pgd;
  39                 S390_lowcore.user_exec_asce = mm->context | __pa(shadow_pgd);
  40                 asm volatile(LCTL_OPCODE" 1,1,%0\n"
  41                              : : "m" (S390_lowcore.user_exec_asce) );
  42         } else
  43                 /* Load home space page table origin. */
  44                 asm volatile(LCTL_OPCODE" 13,13,%0"
  45                              : : "m" (S390_lowcore.user_asce) );
  46 }
  47
  48 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  49                              struct task_struct *tsk)
  50 {
  51         if (unlikely(prev == next))
  52                 return;
  53         cpu_set(smp_processor_id(), next->cpu_vm_mask);
  54         update_mm(next, tsk);
  55 }
  56
  57 #define enter_lazy_tlb(mm,tsk)  do { } while (0)
  58 #define deactivate_mm(tsk,mm)   do { } while (0)
  59
  60 static inline void activate_mm(struct mm_struct *prev,
  61                                struct mm_struct *next)
  62 {
  63         switch_mm(prev, next, current);
  64         set_fs(current->thread.mm_segment);
  65 }
  66
  67 #endif /* __S390_MMU_CONTEXT_H */