arch/um/include/asm/tlb.h

   1 #ifndef __UM_TLB_H
   2 #define __UM_TLB_H
   3
   4 #include <linux/pagemap.h>
   5 #include <linux/swap.h>
   6 #include <asm/percpu.h>
   7 #include <asm/pgalloc.h>
   8 #include <asm/tlbflush.h>
   9
  10 #define tlb_start_vma(tlb, vma) do { } while (0)
  11 #define tlb_end_vma(tlb, vma) do { } while (0)
  12 #define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
  13
  14 /* struct mmu_gather is an opaque type used by the mm code for passing around
  15  * any data needed by arch specific code for tlb_remove_page.
  16  */
  17 struct mmu_gather {
  18         struct mm_struct        *mm;
  19         unsigned int            need_flush; /* Really unmapped some ptes? */
  20         unsigned long           start;
  21         unsigned long           end;
  22         unsigned int            fullmm; /* non-zero means full mm flush */
  23 };
  24
  25 static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
  26                                           unsigned long address)
  27 {
  28         if (tlb->start > address)
  29                 tlb->start = address;
  30         if (tlb->end < address + PAGE_SIZE)
  31                 tlb->end = address + PAGE_SIZE;
  32 }
  33
  34 static inline void init_tlb_gather(struct mmu_gather *tlb)
  35 {
  36         tlb->need_flush = 0;
  37
  38         tlb->start = TASK_SIZE;
  39         tlb->end = 0;
  40
  41         if (tlb->fullmm) {
  42                 tlb->start = 0;
  43                 tlb->end = TASK_SIZE;
  44         }
  45 }
  46
  47 static inline void
  48 arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
  49                 unsigned long start, unsigned long end)
  50 {
  51         tlb->mm = mm;
  52         tlb->start = start;
  53         tlb->end = end;
  54         tlb->fullmm = !(start | (end+1));
  55
  56         init_tlb_gather(tlb);
  57 }
  58
  59 extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
  60                                unsigned long end);
  61
  62 static inline void
  63 tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
  64 {
  65         flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
  66 }
  67
  68 static inline void
  69 tlb_flush_mmu_free(struct mmu_gather *tlb)
  70 {
  71         init_tlb_gather(tlb);
  72 }
  73
  74 static inline void
  75 tlb_flush_mmu(struct mmu_gather *tlb)
  76 {
  77         if (!tlb->need_flush)
  78                 return;
  79
  80         tlb_flush_mmu_tlbonly(tlb);
  81         tlb_flush_mmu_free(tlb);
  82 }
  83
  84 /* arch_tlb_finish_mmu
  85  *      Called at the end of the shootdown operation to free up any resources
  86  *      that were required.
  87  */
  88 static inline void
  89 arch_tlb_finish_mmu(struct mmu_gather *tlb,
  90                 unsigned long start, unsigned long end, bool force)
  91 {
  92         if (force) {
  93                 tlb->start = start;
  94                 tlb->end = end;
  95                 tlb->need_flush = 1;
  96         }
  97         tlb_flush_mmu(tlb);
  98
  99         /* keep the page table cache within bounds */
 100         check_pgt_cache();
 101 }
 102
 103 /* tlb_remove_page
 104  *      Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)),
 105  *      while handling the additional races in SMP caused by other CPUs
 106  *      caching valid mappings in their TLBs.
 107  */
 108 static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 109 {
 110         tlb->need_flush = 1;
 111         free_page_and_swap_cache(page);
 112         return false; /* avoid calling tlb_flush_mmu */
 113 }
 114
 115 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 116 {
 117         __tlb_remove_page(tlb, page);
 118 }
 119
 120 static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
 121                                           struct page *page, int page_size)
 122 {
 123         return __tlb_remove_page(tlb, page);
 124 }
 125
 126 static inline void tlb_remove_page_size(struct mmu_gather *tlb,
 127                                         struct page *page, int page_size)
 128 {
 129         return tlb_remove_page(tlb, page);
 130 }
 131
 132 /**
 133  * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
 134  *
 135  * Record the fact that pte's were really umapped in ->need_flush, so we can
 136  * later optimise away the tlb invalidate.   This helps when userspace is
 137  * unmapping already-unmapped pages, which happens quite a lot.
 138  */
 139 #define tlb_remove_tlb_entry(tlb, ptep, address)                \
 140         do {                                                    \
 141                 tlb->need_flush = 1;                            \
 142                 __tlb_remove_tlb_entry(tlb, ptep, address);     \
 143         } while (0)
 144
 145 #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address)        \
 146         tlb_remove_tlb_entry(tlb, ptep, address)
 147
 148 #define tlb_remove_check_page_size_change tlb_remove_check_page_size_change
 149 static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
 150                                                      unsigned int page_size)
 151 {
 152 }
 153
 154 #define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
 155
 156 #define pud_free_tlb(tlb, pudp, addr) __pud_free_tlb(tlb, pudp, addr)
 157
 158 #define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
 159
 160 #define tlb_migrate_finish(mm) do {} while (0)
 161
 162 #endif