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
  23 #include <asm-generic/tlb.h>
  24
  25 /*
  26  * There's three ways the TLB shootdown code is used:
  27  *  1. Unmapping a range of vmas.  See zap_page_range(), unmap_region().
  28  *     tlb->fullmm = 0, and tlb_start_vma/tlb_end_vma will be called.
  29  *  2. Unmapping all vmas.  See exit_mmap().
  30  *     tlb->fullmm = 1, and tlb_start_vma/tlb_end_vma will be called.
  31  *     Page tables will be freed.
  32  *  3. Unmapping argument pages.  See shift_arg_pages().
  33  *     tlb->fullmm = 0, but tlb_start_vma/tlb_end_vma will not be called.
  34  */
  35 static inline void tlb_flush(struct mmu_gather *tlb)
  36 {
  37         if (tlb->fullmm) {
  38                 flush_tlb_mm(tlb->mm);
  39         } else if (tlb->end > 0) {
  40                 struct vm_area_struct vma = { .vm_mm = tlb->mm, };
  41                 flush_tlb_range(&vma, tlb->start, tlb->end);
  42                 tlb->start = TASK_SIZE;
  43                 tlb->end = 0;
  44         }
  45 }
  46
  47 static inline void tlb_add_flush(struct mmu_gather *tlb, unsigned long addr)
  48 {
  49         if (!tlb->fullmm) {
  50                 tlb->start = min(tlb->start, addr);
  51                 tlb->end = max(tlb->end, addr + PAGE_SIZE);
  52         }
  53 }
  54
  55 /*
  56  * Memorize the range for the TLB flush.
  57  */
  58 static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
  59                                           unsigned long addr)
  60 {
  61         tlb_add_flush(tlb, addr);
  62 }
  63
  64 /*
  65  * In the case of tlb vma handling, we can optimise these away in the
  66  * case where we're doing a full MM flush.  When we're doing a munmap,
  67  * the vmas are adjusted to only cover the region to be torn down.
  68  */
  69 static inline void tlb_start_vma(struct mmu_gather *tlb,
  70                                  struct vm_area_struct *vma)
  71 {
  72         if (!tlb->fullmm) {
  73                 tlb->start = TASK_SIZE;
  74                 tlb->end = 0;
  75         }
  76 }
  77
  78 static inline void tlb_end_vma(struct mmu_gather *tlb,
  79                                struct vm_area_struct *vma)
  80 {
  81         if (!tlb->fullmm)
  82                 tlb_flush(tlb);
  83 }
  84
  85 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
  86                                   unsigned long addr)
  87 {
  88         pgtable_page_dtor(pte);
  89         tlb_add_flush(tlb, addr);
  90         tlb_remove_page(tlb, pte);
  91 }
  92
  93 #ifndef CONFIG_ARM64_64K_PAGES
  94 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
  95                                   unsigned long addr)
  96 {
  97         tlb_add_flush(tlb, addr);
  98         tlb_remove_page(tlb, virt_to_page(pmdp));
  99 }
 100 #endif
 101
 102
 103 #endif