| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/include/asm-arm/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 | #include <asm/pgalloc.h> |
| 23 | |
| 24 | /* |
| 25 | * TLB handling. This allows us to remove pages from the page |
| 26 | * tables, and efficiently handle the TLB issues. |
| 27 | */ |
| 28 | struct mmu_gather { |
| 29 | struct mm_struct *mm; |
| 30 | unsigned int freed; |
| 31 | unsigned int fullmm; |
| 32 | |
| 33 | unsigned int flushes; |
| 34 | unsigned int avoided_flushes; |
| 35 | }; |
| 36 | |
| 37 | DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); |
| 38 | |
| 39 | static inline struct mmu_gather * |
| 40 | tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) |
| 41 | { |
| 42 | int cpu = smp_processor_id(); |
| 43 | struct mmu_gather *tlb = &per_cpu(mmu_gathers, cpu); |
| 44 | |
| 45 | tlb->mm = mm; |
| 46 | tlb->freed = 0; |
| 47 | tlb->fullmm = full_mm_flush; |
| 48 | |
| 49 | return tlb; |
| 50 | } |
| 51 | |
| 52 | static inline void |
| 53 | tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) |
| 54 | { |
| 55 | struct mm_struct *mm = tlb->mm; |
| 56 | unsigned long freed = tlb->freed; |
| 57 | int rss = get_mm_counter(mm, rss); |
| 58 | |
| 59 | if (rss < freed) |
| 60 | freed = rss; |
| 61 | add_mm_counter(mm, rss, -freed); |
| 62 | |
| 63 | if (tlb->fullmm) |
| 64 | flush_tlb_mm(mm); |
| 65 | |
| 66 | /* keep the page table cache within bounds */ |
| 67 | check_pgt_cache(); |
| 68 | } |
| 69 | |
| 70 | static inline unsigned int tlb_is_full_mm(struct mmu_gather *tlb) |
| 71 | { |
| 72 | return tlb->fullmm; |
| 73 | } |
| 74 | |
| 75 | #define tlb_remove_tlb_entry(tlb,ptep,address) do { } while (0) |
| 76 | |
| 77 | /* |
| 78 | * In the case of tlb vma handling, we can optimise these away in the |
| 79 | * case where we're doing a full MM flush. When we're doing a munmap, |
| 80 | * the vmas are adjusted to only cover the region to be torn down. |
| 81 | */ |
| 82 | static inline void |
| 83 | tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) |
| 84 | { |
| 85 | if (!tlb->fullmm) |
| 86 | flush_cache_range(vma, vma->vm_start, vma->vm_end); |
| 87 | } |
| 88 | |
| 89 | static inline void |
| 90 | tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) |
| 91 | { |
| 92 | if (!tlb->fullmm) |
| 93 | flush_tlb_range(vma, vma->vm_start, vma->vm_end); |
| 94 | } |
| 95 | |
| 96 | #define tlb_remove_page(tlb,page) free_page_and_swap_cache(page) |
| 97 | #define pte_free_tlb(tlb,ptep) pte_free(ptep) |
| 98 | #define pmd_free_tlb(tlb,pmdp) pmd_free(pmdp) |
| 99 | |
| 100 | #define tlb_migrate_finish(mm) do { } while (0) |
| 101 | |
| 102 | #endif |