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