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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 /*
  14  * get a new mmu context.. S390 don't know about contexts.
  15  */
  16 #define init_new_context(tsk,mm)        0
  17
  18 #define destroy_context(mm)             do { } while (0)
  19
  20 #ifndef __s390x__
  21 #define LCTL_OPCODE "lctl"
  22 #define PGTABLE_BITS (_SEGMENT_TABLE|USER_STD_MASK)
  23 #else
  24 #define LCTL_OPCODE "lctlg"
  25 #define PGTABLE_BITS (_REGION_TABLE|USER_STD_MASK)
  26 #endif
  27
  28 static inline void enter_lazy_tlb(struct mm_struct *mm,
  29                                   struct task_struct *tsk)
  30 {
  31 }
  32
  33 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  34                              struct task_struct *tsk)
  35 {
  36         pgd_t *shadow_pgd = get_shadow_pgd(next->pgd);
  37
  38         if (prev != next) {
  39                 S390_lowcore.user_asce = (__pa(next->pgd) & PAGE_MASK) |
  40                                          PGTABLE_BITS;
  41                 if (shadow_pgd) {
  42                         /* Load primary/secondary space page table origin. */
  43                         S390_lowcore.user_exec_asce =
  44                                 (__pa(shadow_pgd) & PAGE_MASK) | PGTABLE_BITS;
  45                         asm volatile(LCTL_OPCODE" 1,1,%0\n"
  46                                      LCTL_OPCODE" 7,7,%1"
  47                                      : : "m" (S390_lowcore.user_exec_asce),
  48                                          "m" (S390_lowcore.user_asce) );
  49                 } else if (switch_amode) {
  50                         /* Load primary space page table origin. */
  51                         asm volatile(LCTL_OPCODE" 1,1,%0"
  52                                      : : "m" (S390_lowcore.user_asce) );
  53                 } else
  54                         /* Load home space page table origin. */
  55                         asm volatile(LCTL_OPCODE" 13,13,%0"
  56                                      : : "m" (S390_lowcore.user_asce) );
  57         }
  58         cpu_set(smp_processor_id(), next->cpu_vm_mask);
  59 }
  60
  61 #define deactivate_mm(tsk,mm)   do { } while (0)
  62
  63 static inline void activate_mm(struct mm_struct *prev,
  64                                struct mm_struct *next)
  65 {
  66         switch_mm(prev, next, current);
  67         set_fs(current->thread.mm_segment);
  68 }
  69
  70 #endif /* __S390_MMU_CONTEXT_H */