arch/um/include/asm/tlb.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __UM_TLB_H
   3 #define __UM_TLB_H
   4
   5 #include <linux/pagemap.h>
   6 #include <linux/swap.h>
   7 #include <asm/percpu.h>
   8 #include <asm/pgalloc.h>
   9 #include <asm/tlbflush.h>
  10
  11 #define tlb_start_vma(tlb, vma) do { } while (0)
  12 #define tlb_end_vma(tlb, vma) do { } while (0)
  13 #define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
  14
  15 /* struct mmu_gather is an opaque type used by the mm code for passing around
  16  * any data needed by arch specific code for tlb_remove_page.
  17  */
  18 struct mmu_gather {
  19         struct mm_struct        *mm;
  20         unsigned int            need_flush; /* Really unmapped some ptes? */
  21         unsigned long           start;
  22         unsigned long           end;
  23         unsigned int            fullmm; /* non-zero means full mm flush */
  24 };
  25
  26 static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
  27                                           unsigned long address)
  28 {
  29         if (tlb->start > address)
  30                 tlb->start = address;
  31         if (tlb->end < address + PAGE_SIZE)
  32                 tlb->end = address + PAGE_SIZE;
  33 }
  34
  35 static inline void init_tlb_gather(struct mmu_gather *tlb)
  36 {
  37         tlb->need_flush = 0;
  38
  39         tlb->start = TASK_SIZE;
  40         tlb->end = 0;
  41
  42         if (tlb->fullmm) {
  43                 tlb->start = 0;
  44                 tlb->end = TASK_SIZE;
  45         }
  46 }
  47
  48 static inline void
  49 arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
  50                 unsigned long start, unsigned long end)
  51 {
  52         tlb->mm = mm;
  53         tlb->start = start;
  54         tlb->end = end;
  55         tlb->fullmm = !(start | (end+1));
  56
  57         init_tlb_gather(tlb);
  58 }
  59
  60 extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
  61                                unsigned long end);
  62
  63 static inline void
  64 tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
  65 {
  66         flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
  67 }
  68
  69 static inline void
  70 tlb_flush_mmu_free(struct mmu_gather *tlb)
  71 {
  72         init_tlb_gather(tlb);
  73 }
  74
  75 static inline void
  76 tlb_flush_mmu(struct mmu_gather *tlb)
  77 {
  78         if (!tlb->need_flush)
  79                 return;
  80
  81         tlb_flush_mmu_tlbonly(tlb);
  82         tlb_flush_mmu_free(tlb);
  83 }
  84
  85 /* arch_tlb_finish_mmu
  86  *      Called at the end of the shootdown operation to free up any resources
  87  *      that were required.
  88  */
  89 static inline void
  90 arch_tlb_finish_mmu(struct mmu_gather *tlb,
  91                 unsigned long start, unsigned long end, bool force)
  92 {
  93         if (force) {
  94                 tlb->start = start;
  95                 tlb->end = end;
  96                 tlb->need_flush = 1;
  97         }
  98         tlb_flush_mmu(tlb);
  99
 100         /* keep the page table cache within bounds */
 101         check_pgt_cache();
 102 }
 103
 104 /* tlb_remove_page
 105  *      Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)),
 106  *      while handling the additional races in SMP caused by other CPUs
 107  *      caching valid mappings in their TLBs.
 108  */
 109 static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 110 {
 111         tlb->need_flush = 1;
 112         free_page_and_swap_cache(page);
 113         return false; /* avoid calling tlb_flush_mmu */
 114 }
 115
 116 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 117 {
 118         __tlb_remove_page(tlb, page);
 119 }
 120
 121 static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
 122                                           struct page *page, int page_size)
 123 {
 124         return __tlb_remove_page(tlb, page);
 125 }
 126
 127 static inline void tlb_remove_page_size(struct mmu_gather *tlb,
 128                                         struct page *page, int page_size)
 129 {
 130         return tlb_remove_page(tlb, page);
 131 }
 132
 133 /**
 134  * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
 135  *
 136  * Record the fact that pte's were really umapped in ->need_flush, so we can
 137  * later optimise away the tlb invalidate.   This helps when userspace is
 138  * unmapping already-unmapped pages, which happens quite a lot.
 139  */
 140 #define tlb_remove_tlb_entry(tlb, ptep, address)                \
 141         do {                                                    \
 142                 tlb->need_flush = 1;                            \
 143                 __tlb_remove_tlb_entry(tlb, ptep, address);     \
 144         } while (0)
 145
 146 #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address)        \
 147         tlb_remove_tlb_entry(tlb, ptep, address)
 148
 149 #define tlb_remove_check_page_size_change tlb_remove_check_page_size_change
 150 static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
 151                                                      unsigned int page_size)
 152 {
 153 }
 154
 155 #define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
 156
 157 #define pud_free_tlb(tlb, pudp, addr) __pud_free_tlb(tlb, pudp, addr)
 158
 159 #define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
 160
 161 #define tlb_migrate_finish(mm) do {} while (0)
 162
 163 #endif