arch/s390/include/asm/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/uaccess.h>
  14 #include <asm-generic/mm_hooks.h>
  15
  16 static inline int init_new_context(struct task_struct *tsk,
  17                                    struct mm_struct *mm)
  18 {
  19         mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
  20 #ifdef CONFIG_64BIT
  21         mm->context.asce_bits |= _ASCE_TYPE_REGION3;
  22 #endif
  23         if (current->mm->context.pgstes) {
  24                 mm->context.noexec = 0;
  25                 mm->context.pgstes = 1;
  26         } else {
  27                 mm->context.noexec = s390_noexec;
  28                 mm->context.pgstes = 0;
  29         }
  30         mm->context.asce_limit = STACK_TOP_MAX;
  31         crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
  32         return 0;
  33 }
  34
  35 #define destroy_context(mm)             do { } while (0)
  36
  37 #ifndef __s390x__
  38 #define LCTL_OPCODE "lctl"
  39 #else
  40 #define LCTL_OPCODE "lctlg"
  41 #endif
  42
  43 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
  44 {
  45         pgd_t *pgd = mm->pgd;
  46
  47         S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
  48         if (switch_amode) {
  49                 /* Load primary space page table origin. */
  50                 pgd = mm->context.noexec ? get_shadow_table(pgd) : pgd;
  51                 S390_lowcore.user_exec_asce = mm->context.asce_bits | __pa(pgd);
  52                 asm volatile(LCTL_OPCODE" 1,1,%0\n"
  53                              : : "m" (S390_lowcore.user_exec_asce) );
  54         } else
  55                 /* Load home space page table origin. */
  56                 asm volatile(LCTL_OPCODE" 13,13,%0"
  57                              : : "m" (S390_lowcore.user_asce) );
  58         set_fs(current->thread.mm_segment);
  59 }
  60
  61 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  62                              struct task_struct *tsk)
  63 {
  64         cpu_set(smp_processor_id(), next->cpu_vm_mask);
  65         update_mm(next, tsk);
  66 }
  67
  68 #define enter_lazy_tlb(mm,tsk)  do { } while (0)
  69 #define deactivate_mm(tsk,mm)   do { } while (0)
  70
  71 static inline void activate_mm(struct mm_struct *prev,
  72                                struct mm_struct *next)
  73 {
  74         switch_mm(prev, next, current);
  75 }
  76
  77 #endif /* __S390_MMU_CONTEXT_H */