arch/s390/include/asm/mmu_context.h

   1 /*
   2  *  S390 version
   3  *
   4  *  Derived from "include/asm-i386/mmu_context.h"
   5  */
   6
   7 #ifndef __S390_MMU_CONTEXT_H
   8 #define __S390_MMU_CONTEXT_H
   9
  10 #include <asm/pgalloc.h>
  11 #include <asm/uaccess.h>
  12 #include <asm/tlbflush.h>
  13 #include <asm/ctl_reg.h>
  14
  15 static inline int init_new_context(struct task_struct *tsk,
  16                                    struct mm_struct *mm)
  17 {
  18         atomic_set(&mm->context.attach_count, 0);
  19         mm->context.flush_mm = 0;
  20         mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
  21 #ifdef CONFIG_64BIT
  22         mm->context.asce_bits |= _ASCE_TYPE_REGION3;
  23 #endif
  24         mm->context.has_pgste = 0;
  25         mm->context.asce_limit = STACK_TOP_MAX;
  26         crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
  27         return 0;
  28 }
  29
  30 #define destroy_context(mm)             do { } while (0)
  31
  32 #ifndef CONFIG_64BIT
  33 #define LCTL_OPCODE "lctl"
  34 #else
  35 #define LCTL_OPCODE "lctlg"
  36 #endif
  37
  38 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
  39 {
  40         pgd_t *pgd = mm->pgd;
  41
  42         S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
  43         if (s390_user_mode != HOME_SPACE_MODE) {
  44                 /* Load primary space page table origin. */
  45                 asm volatile(LCTL_OPCODE" 1,1,%0\n"
  46                              : : "m" (S390_lowcore.user_asce) );
  47         } else
  48                 /* Load home space page table origin. */
  49                 asm volatile(LCTL_OPCODE" 13,13,%0"
  50                              : : "m" (S390_lowcore.user_asce) );
  51         set_fs(current->thread.mm_segment);
  52 }
  53
  54 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  55                              struct task_struct *tsk)
  56 {
  57         cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
  58         update_mm(next, tsk);
  59         atomic_dec(&prev->context.attach_count);
  60         WARN_ON(atomic_read(&prev->context.attach_count) < 0);
  61         atomic_inc(&next->context.attach_count);
  62         /* Check for TLBs not flushed yet */
  63         __tlb_flush_mm_lazy(next);
  64 }
  65
  66 #define enter_lazy_tlb(mm,tsk)  do { } while (0)
  67 #define deactivate_mm(tsk,mm)   do { } while (0)
  68
  69 static inline void activate_mm(struct mm_struct *prev,
  70                                struct mm_struct *next)
  71 {
  72         switch_mm(prev, next, current);
  73 }
  74
  75 static inline void arch_dup_mmap(struct mm_struct *oldmm,
  76                                  struct mm_struct *mm)
  77 {
  78 #ifdef CONFIG_64BIT
  79         if (oldmm->context.asce_limit < mm->context.asce_limit)
  80                 crst_table_downgrade(mm, oldmm->context.asce_limit);
  81 #endif
  82 }
  83
  84 static inline void arch_exit_mmap(struct mm_struct *mm)
  85 {
  86 }
  87
  88 #endif /* __S390_MMU_CONTEXT_H */