arch/arm64/include/asm/tlb.h

   1 /*
   2  * Based on arch/arm/include/asm/tlb.h
   3  *
   4  * Copyright (C) 2002 Russell King
   5  * Copyright (C) 2012 ARM Ltd.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #ifndef __ASM_TLB_H
  20 #define __ASM_TLB_H
  21
  22 #define  __tlb_remove_pmd_tlb_entry __tlb_remove_pmd_tlb_entry
  23
  24 #include <asm-generic/tlb.h>
  25
  26 #include <linux/pagemap.h>
  27 #include <linux/swap.h>
  28
  29 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
  30
  31 #define tlb_remove_entry(tlb, entry)    tlb_remove_table(tlb, entry)
  32 static inline void __tlb_remove_table(void *_table)
  33 {
  34         free_page_and_swap_cache((struct page *)_table);
  35 }
  36 #else
  37 #define tlb_remove_entry(tlb, entry)    tlb_remove_page(tlb, entry)
  38 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */
  39
  40 /*
  41  * There's three ways the TLB shootdown code is used:
  42  *  1. Unmapping a range of vmas.  See zap_page_range(), unmap_region().
  43  *     tlb->fullmm = 0, and tlb_start_vma/tlb_end_vma will be called.
  44  *  2. Unmapping all vmas.  See exit_mmap().
  45  *     tlb->fullmm = 1, and tlb_start_vma/tlb_end_vma will be called.
  46  *     Page tables will be freed.
  47  *  3. Unmapping argument pages.  See shift_arg_pages().
  48  *     tlb->fullmm = 0, but tlb_start_vma/tlb_end_vma will not be called.
  49  */
  50 static inline void tlb_flush(struct mmu_gather *tlb)
  51 {
  52         if (tlb->fullmm) {
  53                 flush_tlb_mm(tlb->mm);
  54         } else if (tlb->end > 0) {
  55                 struct vm_area_struct vma = { .vm_mm = tlb->mm, };
  56                 flush_tlb_range(&vma, tlb->start, tlb->end);
  57                 tlb->start = TASK_SIZE;
  58                 tlb->end = 0;
  59         }
  60 }
  61
  62 static inline void tlb_add_flush(struct mmu_gather *tlb, unsigned long addr)
  63 {
  64         if (!tlb->fullmm) {
  65                 tlb->start = min(tlb->start, addr);
  66                 tlb->end = max(tlb->end, addr + PAGE_SIZE);
  67         }
  68 }
  69
  70 /*
  71  * Memorize the range for the TLB flush.
  72  */
  73 static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
  74                                           unsigned long addr)
  75 {
  76         tlb_add_flush(tlb, addr);
  77 }
  78
  79 /*
  80  * In the case of tlb vma handling, we can optimise these away in the
  81  * case where we're doing a full MM flush.  When we're doing a munmap,
  82  * the vmas are adjusted to only cover the region to be torn down.
  83  */
  84 static inline void tlb_start_vma(struct mmu_gather *tlb,
  85                                  struct vm_area_struct *vma)
  86 {
  87         if (!tlb->fullmm) {
  88                 tlb->start = TASK_SIZE;
  89                 tlb->end = 0;
  90         }
  91 }
  92
  93 static inline void tlb_end_vma(struct mmu_gather *tlb,
  94                                struct vm_area_struct *vma)
  95 {
  96         if (!tlb->fullmm)
  97                 tlb_flush(tlb);
  98 }
  99
 100 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
 101                                   unsigned long addr)
 102 {
 103         pgtable_page_dtor(pte);
 104         tlb_add_flush(tlb, addr);
 105         tlb_remove_entry(tlb, pte);
 106 }
 107
 108 #if CONFIG_ARM64_PGTABLE_LEVELS > 2
 109 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
 110                                   unsigned long addr)
 111 {
 112         tlb_add_flush(tlb, addr);
 113         tlb_remove_entry(tlb, virt_to_page(pmdp));
 114 }
 115 #endif
 116
 117 #if CONFIG_ARM64_PGTABLE_LEVELS > 3
 118 static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp,
 119                                   unsigned long addr)
 120 {
 121         tlb_add_flush(tlb, addr);
 122         tlb_remove_entry(tlb, virt_to_page(pudp));
 123 }
 124 #endif
 125
 126 static inline void __tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp,
 127                                                 unsigned long address)
 128 {
 129         tlb_add_flush(tlb, address);
 130 }
 131
 132 #endif