arch/metag/include/asm/mmu_context.h

   1 #ifndef __METAG_MMU_CONTEXT_H
   2 #define __METAG_MMU_CONTEXT_H
   3
   4 #include <asm-generic/mm_hooks.h>
   5
   6 #include <asm/page.h>
   7 #include <asm/mmu.h>
   8 #include <asm/tlbflush.h>
   9 #include <asm/cacheflush.h>
  10
  11 #include <linux/io.h>
  12 #include <linux/mm_types.h>
  13
  14 static inline void enter_lazy_tlb(struct mm_struct *mm,
  15                                   struct task_struct *tsk)
  16 {
  17 }
  18
  19 static inline int init_new_context(struct task_struct *tsk,
  20                                    struct mm_struct *mm)
  21 {
  22 #ifndef CONFIG_METAG_META21_MMU
  23         /* We use context to store a pointer to the page holding the
  24          * pgd of a process while it is running. While a process is not
  25          * running the pgd and context fields should be equal.
  26          */
  27         mm->context.pgd_base = (unsigned long) mm->pgd;
  28 #endif
  29 #ifdef CONFIG_METAG_USER_TCM
  30         INIT_LIST_HEAD(&mm->context.tcm);
  31 #endif
  32         return 0;
  33 }
  34
  35 #ifdef CONFIG_METAG_USER_TCM
  36
  37 #include <linux/slab.h>
  38 #include <asm/tcm.h>
  39
  40 static inline void destroy_context(struct mm_struct *mm)
  41 {
  42         struct tcm_allocation *pos, *n;
  43
  44         list_for_each_entry_safe(pos, n,  &mm->context.tcm, list) {
  45                 tcm_free(pos->tag, pos->addr, pos->size);
  46                 list_del(&pos->list);
  47                 kfree(pos);
  48         }
  49 }
  50 #else
  51 #define destroy_context(mm)             do { } while (0)
  52 #endif
  53
  54 #ifdef CONFIG_METAG_META21_MMU
  55 static inline void load_pgd(pgd_t *pgd, int thread)
  56 {
  57         unsigned long phys0 = mmu_phys0_addr(thread);
  58         unsigned long phys1 = mmu_phys1_addr(thread);
  59
  60         /*
  61          *  0x900 2Gb address space
  62          *  The permission bits apply to MMU table region which gives a 2MB
  63          *  window into physical memory. We especially don't want userland to be
  64          *  able to access this.
  65          */
  66         metag_out32(0x900 | _PAGE_CACHEABLE | _PAGE_PRIV | _PAGE_WRITE |
  67                     _PAGE_PRESENT, phys0);
  68         /* Set new MMU base address */
  69         metag_out32(__pa(pgd) & MMCU_TBLPHYS1_ADDR_BITS, phys1);
  70 }
  71 #endif
  72
  73 static inline void switch_mmu(struct mm_struct *prev, struct mm_struct *next)
  74 {
  75 #ifdef CONFIG_METAG_META21_MMU
  76         load_pgd(next->pgd, hard_processor_id());
  77 #else
  78         unsigned int i;
  79
  80         /* prev->context == prev->pgd in the case where we are initially
  81            switching from the init task to the first process. */
  82         if (prev->context.pgd_base != (unsigned long) prev->pgd) {
  83                 for (i = FIRST_USER_PGD_NR; i < USER_PTRS_PER_PGD; i++)
  84                         ((pgd_t *) prev->context.pgd_base)[i] = prev->pgd[i];
  85         } else
  86                 prev->pgd = (pgd_t *)mmu_get_base();
  87
  88         next->pgd = prev->pgd;
  89         prev->pgd = (pgd_t *) prev->context.pgd_base;
  90
  91         for (i = FIRST_USER_PGD_NR; i < USER_PTRS_PER_PGD; i++)
  92                 next->pgd[i] = ((pgd_t *) next->context.pgd_base)[i];
  93
  94         flush_cache_all();
  95 #endif
  96         flush_tlb_all();
  97 }
  98
  99 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 100                              struct task_struct *tsk)
 101 {
 102         if (prev != next)
 103                 switch_mmu(prev, next);
 104 }
 105
 106 static inline void activate_mm(struct mm_struct *prev_mm,
 107                                struct mm_struct *next_mm)
 108 {
 109         switch_mmu(prev_mm, next_mm);
 110 }
 111
 112 #define deactivate_mm(tsk, mm)   do { } while (0)
 113
 114 #endif