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   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 /*
  16  * get a new mmu context.. S390 don't know about contexts.
  17  */
  18 #define init_new_context(tsk,mm)        0
  19
  20 #define destroy_context(mm)             do { } while (0)
  21
  22 #ifndef __s390x__
  23 #define LCTL_OPCODE "lctl"
  24 #define PGTABLE_BITS (_SEGMENT_TABLE|USER_STD_MASK)
  25 #else
  26 #define LCTL_OPCODE "lctlg"
  27 #define PGTABLE_BITS (_REGION_TABLE|USER_STD_MASK)
  28 #endif
  29
  30 static inline void enter_lazy_tlb(struct mm_struct *mm,
  31                                   struct task_struct *tsk)
  32 {
  33 }
  34
  35 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  36                              struct task_struct *tsk)
  37 {
  38         pgd_t *shadow_pgd = get_shadow_pgd(next->pgd);
  39
  40         if (prev != next) {
  41                 S390_lowcore.user_asce = (__pa(next->pgd) & PAGE_MASK) |
  42                                          PGTABLE_BITS;
  43                 if (shadow_pgd) {
  44                         /* Load primary/secondary space page table origin. */
  45                         S390_lowcore.user_exec_asce =
  46                                 (__pa(shadow_pgd) & PAGE_MASK) | PGTABLE_BITS;
  47                         asm volatile(LCTL_OPCODE" 1,1,%0\n"
  48                                      LCTL_OPCODE" 7,7,%1"
  49                                      : : "m" (S390_lowcore.user_exec_asce),
  50                                          "m" (S390_lowcore.user_asce) );
  51                 } else if (switch_amode) {
  52                         /* Load primary space page table origin. */
  53                         asm volatile(LCTL_OPCODE" 1,1,%0"
  54                                      : : "m" (S390_lowcore.user_asce) );
  55                 } else
  56                         /* Load home space page table origin. */
  57                         asm volatile(LCTL_OPCODE" 13,13,%0"
  58                                      : : "m" (S390_lowcore.user_asce) );
  59         }
  60         cpu_set(smp_processor_id(), next->cpu_vm_mask);
  61 }
  62
  63 #define deactivate_mm(tsk,mm)   do { } while (0)
  64
  65 static inline void activate_mm(struct mm_struct *prev,
  66                                struct mm_struct *next)
  67 {
  68         switch_mm(prev, next, current);
  69         set_fs(current->thread.mm_segment);
  70 }
  71
  72 #endif /* __S390_MMU_CONTEXT_H */