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 tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long start, unsigned long end)
  49 {
  50         tlb->mm = mm;
  51         tlb->start = start;
  52         tlb->end = end;
  53         tlb->fullmm = !(start | (end+1));
  54
  55         init_tlb_gather(tlb);
  56 }
  57
  58 extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
  59                                unsigned long end);
  60
  61 static inline void
  62 tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
  63 {
  64         flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
  65 }
  66
  67 static inline void
  68 tlb_flush_mmu_free(struct mmu_gather *tlb)
  69 {
  70         init_tlb_gather(tlb);
  71 }
  72
  73 static inline void
  74 tlb_flush_mmu(struct mmu_gather *tlb)
  75 {
  76         if (!tlb->need_flush)
  77                 return;
  78
  79         tlb_flush_mmu_tlbonly(tlb);
  80         tlb_flush_mmu_free(tlb);
  81 }
  82
  83 /* tlb_finish_mmu
  84  *      Called at the end of the shootdown operation to free up any resources
  85  *      that were required.
  86  */
  87 static inline void
  88 tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
  89 {
  90         tlb_flush_mmu(tlb);
  91
  92         /* keep the page table cache within bounds */
  93         check_pgt_cache();
  94 }
  95
  96 /* tlb_remove_page
  97  *      Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)),
  98  *      while handling the additional races in SMP caused by other CPUs
  99  *      caching valid mappings in their TLBs.
 100  */
 101 static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 102 {
 103         tlb->need_flush = 1;
 104         free_page_and_swap_cache(page);
 105         return 1; /* avoid calling tlb_flush_mmu */
 106 }
 107
 108 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 109 {
 110         __tlb_remove_page(tlb, page);
 111 }
 112
 113 /**
 114  * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
 115  *
 116  * Record the fact that pte's were really umapped in ->need_flush, so we can
 117  * later optimise away the tlb invalidate.   This helps when userspace is
 118  * unmapping already-unmapped pages, which happens quite a lot.
 119  */
 120 #define tlb_remove_tlb_entry(tlb, ptep, address)                \
 121         do {                                                    \
 122                 tlb->need_flush = 1;                            \
 123                 __tlb_remove_tlb_entry(tlb, ptep, address);     \
 124         } while (0)
 125
 126 #define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
 127
 128 #define pud_free_tlb(tlb, pudp, addr) __pud_free_tlb(tlb, pudp, addr)
 129
 130 #define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
 131
 132 #define tlb_migrate_finish(mm) do {} while (0)
 133
 134 #endif