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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 */
28struct 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
37DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
38
39static inline struct mmu_gather *
40tlb_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
52static inline void
53tlb_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
70static 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 */
82static inline void
83tlb_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
89static inline void
90tlb_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