arch/arm/include/asm/tlb.h

   1 /*
   2  *  arch/arm/include/asm/tlb.h
   3  *
   4  *  Copyright (C) 2002 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  Experimentation shows that on a StrongARM, it appears to be faster
  11  *  to use the "invalidate whole tlb" rather than "invalidate single
  12  *  tlb" for this.
  13  *
  14  *  This appears true for both the process fork+exit case, as well as
  15  *  the munmap-large-area case.
  16  */
  17 #ifndef __ASMARM_TLB_H
  18 #define __ASMARM_TLB_H
  19
  20 #include <asm/cacheflush.h>
  21 #include <asm/tlbflush.h>
  22
  23 #ifndef CONFIG_MMU
  24
  25 #include <linux/pagemap.h>
  26 #include <asm-generic/tlb.h>
  27
  28 #else /* !CONFIG_MMU */
  29
  30 #include <asm/pgalloc.h>
  31
  32 /*
  33  * TLB handling.  This allows us to remove pages from the page
  34  * tables, and efficiently handle the TLB issues.
  35  */
  36 struct mmu_gather {
  37         struct mm_struct        *mm;
  38         unsigned int            fullmm;
  39 };
  40
  41 DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
  42
  43 static inline struct mmu_gather *
  44 tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
  45 {
  46         struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
  47
  48         tlb->mm = mm;
  49         tlb->fullmm = full_mm_flush;
  50
  51         return tlb;
  52 }
  53
  54 static inline void
  55 tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
  56 {
  57         if (tlb->fullmm)
  58                 flush_tlb_mm(tlb->mm);
  59
  60         /* keep the page table cache within bounds */
  61         check_pgt_cache();
  62
  63         put_cpu_var(mmu_gathers);
  64 }
  65
  66 #define tlb_remove_tlb_entry(tlb,ptep,address)  do { } while (0)
  67
  68 /*
  69  * In the case of tlb vma handling, we can optimise these away in the
  70  * case where we're doing a full MM flush.  When we're doing a munmap,
  71  * the vmas are adjusted to only cover the region to be torn down.
  72  */
  73 static inline void
  74 tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
  75 {
  76         if (!tlb->fullmm)
  77                 flush_cache_range(vma, vma->vm_start, vma->vm_end);
  78 }
  79
  80 static inline void
  81 tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
  82 {
  83         if (!tlb->fullmm)
  84                 flush_tlb_range(vma, vma->vm_start, vma->vm_end);
  85 }
  86
  87 #define tlb_remove_page(tlb,page)       free_page_and_swap_cache(page)
  88 #define pte_free_tlb(tlb, ptep)         pte_free((tlb)->mm, ptep)
  89 #define pmd_free_tlb(tlb, pmdp)         pmd_free((tlb)->mm, pmdp)
  90
  91 #define tlb_migrate_finish(mm)          do { } while (0)
  92
  93 #endif /* CONFIG_MMU */
  94 #endif