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 /*
  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 #else
  25 #define LCTL_OPCODE "lctlg"
  26 #endif
  27
  28 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
  29 {
  30         pgd_t *pgd = mm->pgd;
  31         unsigned long asce_bits;
  32
  33         /* Calculate asce bits from the first pgd table entry. */
  34         asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
  35 #ifdef CONFIG_64BIT
  36         asce_bits |= _ASCE_TYPE_REGION3;
  37 #endif
  38         S390_lowcore.user_asce = asce_bits | __pa(pgd);
  39         if (switch_amode) {
  40                 /* Load primary space page table origin. */
  41                 pgd_t *shadow_pgd = get_shadow_table(pgd) ? : pgd;
  42                 S390_lowcore.user_exec_asce = asce_bits | __pa(shadow_pgd);
  43                 asm volatile(LCTL_OPCODE" 1,1,%0\n"
  44                              : : "m" (S390_lowcore.user_exec_asce) );
  45         } else
  46                 /* Load home space page table origin. */
  47                 asm volatile(LCTL_OPCODE" 13,13,%0"
  48                              : : "m" (S390_lowcore.user_asce) );
  49 }
  50
  51 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  52                              struct task_struct *tsk)
  53 {
  54         if (unlikely(prev == next))
  55                 return;
  56         cpu_set(smp_processor_id(), next->cpu_vm_mask);
  57         update_mm(next, tsk);
  58 }
  59
  60 #define enter_lazy_tlb(mm,tsk)  do { } while (0)
  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 */