diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-generic/tlb.h |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-generic/tlb.h')
-rw-r--r-- | include/asm-generic/tlb.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h new file mode 100644 index 00000000000..faff403e106 --- /dev/null +++ b/include/asm-generic/tlb.h | |||
@@ -0,0 +1,160 @@ | |||
1 | /* asm-generic/tlb.h | ||
2 | * | ||
3 | * Generic TLB shootdown code | ||
4 | * | ||
5 | * Copyright 2001 Red Hat, Inc. | ||
6 | * Based on code from mm/memory.c Copyright Linus Torvalds and others. | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or | ||
9 | * modify it under the terms of the GNU General Public License | ||
10 | * as published by the Free Software Foundation; either version | ||
11 | * 2 of the License, or (at your option) any later version. | ||
12 | */ | ||
13 | #ifndef _ASM_GENERIC__TLB_H | ||
14 | #define _ASM_GENERIC__TLB_H | ||
15 | |||
16 | #include <linux/config.h> | ||
17 | #include <linux/swap.h> | ||
18 | #include <asm/pgalloc.h> | ||
19 | #include <asm/tlbflush.h> | ||
20 | |||
21 | /* | ||
22 | * For UP we don't need to worry about TLB flush | ||
23 | * and page free order so much.. | ||
24 | */ | ||
25 | #ifdef CONFIG_SMP | ||
26 | #define FREE_PTE_NR 506 | ||
27 | #define tlb_fast_mode(tlb) ((tlb)->nr == ~0U) | ||
28 | #else | ||
29 | #define FREE_PTE_NR 1 | ||
30 | #define tlb_fast_mode(tlb) 1 | ||
31 | #endif | ||
32 | |||
33 | /* struct mmu_gather is an opaque type used by the mm code for passing around | ||
34 | * any data needed by arch specific code for tlb_remove_page. This structure | ||
35 | * can be per-CPU or per-MM as the page table lock is held for the duration of | ||
36 | * TLB shootdown. | ||
37 | */ | ||
38 | struct mmu_gather { | ||
39 | struct mm_struct *mm; | ||
40 | unsigned int nr; /* set to ~0U means fast mode */ | ||
41 | unsigned int need_flush;/* Really unmapped some ptes? */ | ||
42 | unsigned int fullmm; /* non-zero means full mm flush */ | ||
43 | unsigned long freed; | ||
44 | struct page * pages[FREE_PTE_NR]; | ||
45 | }; | ||
46 | |||
47 | /* Users of the generic TLB shootdown code must declare this storage space. */ | ||
48 | DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); | ||
49 | |||
50 | /* tlb_gather_mmu | ||
51 | * Return a pointer to an initialized struct mmu_gather. | ||
52 | */ | ||
53 | static inline struct mmu_gather * | ||
54 | tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) | ||
55 | { | ||
56 | struct mmu_gather *tlb = &per_cpu(mmu_gathers, smp_processor_id()); | ||
57 | |||
58 | tlb->mm = mm; | ||
59 | |||
60 | /* Use fast mode if only one CPU is online */ | ||
61 | tlb->nr = num_online_cpus() > 1 ? 0U : ~0U; | ||
62 | |||
63 | tlb->fullmm = full_mm_flush; | ||
64 | tlb->freed = 0; | ||
65 | |||
66 | return tlb; | ||
67 | } | ||
68 | |||
69 | static inline void | ||
70 | tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) | ||
71 | { | ||
72 | if (!tlb->need_flush) | ||
73 | return; | ||
74 | tlb->need_flush = 0; | ||
75 | tlb_flush(tlb); | ||
76 | if (!tlb_fast_mode(tlb)) { | ||
77 | free_pages_and_swap_cache(tlb->pages, tlb->nr); | ||
78 | tlb->nr = 0; | ||
79 | } | ||
80 | } | ||
81 | |||
82 | /* tlb_finish_mmu | ||
83 | * Called at the end of the shootdown operation to free up any resources | ||
84 | * that were required. The page table lock is still held at this point. | ||
85 | */ | ||
86 | static inline void | ||
87 | tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) | ||
88 | { | ||
89 | int freed = tlb->freed; | ||
90 | struct mm_struct *mm = tlb->mm; | ||
91 | int rss = get_mm_counter(mm, rss); | ||
92 | |||
93 | if (rss < freed) | ||
94 | freed = rss; | ||
95 | add_mm_counter(mm, rss, -freed); | ||
96 | tlb_flush_mmu(tlb, start, end); | ||
97 | |||
98 | /* keep the page table cache within bounds */ | ||
99 | check_pgt_cache(); | ||
100 | } | ||
101 | |||
102 | static inline unsigned int | ||
103 | tlb_is_full_mm(struct mmu_gather *tlb) | ||
104 | { | ||
105 | return tlb->fullmm; | ||
106 | } | ||
107 | |||
108 | /* tlb_remove_page | ||
109 | * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while | ||
110 | * handling the additional races in SMP caused by other CPUs caching valid | ||
111 | * mappings in their TLBs. | ||
112 | */ | ||
113 | static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) | ||
114 | { | ||
115 | tlb->need_flush = 1; | ||
116 | if (tlb_fast_mode(tlb)) { | ||
117 | free_page_and_swap_cache(page); | ||
118 | return; | ||
119 | } | ||
120 | tlb->pages[tlb->nr++] = page; | ||
121 | if (tlb->nr >= FREE_PTE_NR) | ||
122 | tlb_flush_mmu(tlb, 0, 0); | ||
123 | } | ||
124 | |||
125 | /** | ||
126 | * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation. | ||
127 | * | ||
128 | * Record the fact that pte's were really umapped in ->need_flush, so we can | ||
129 | * later optimise away the tlb invalidate. This helps when userspace is | ||
130 | * unmapping already-unmapped pages, which happens quite a lot. | ||
131 | */ | ||
132 | #define tlb_remove_tlb_entry(tlb, ptep, address) \ | ||
133 | do { \ | ||
134 | tlb->need_flush = 1; \ | ||
135 | __tlb_remove_tlb_entry(tlb, ptep, address); \ | ||
136 | } while (0) | ||
137 | |||
138 | #define pte_free_tlb(tlb, ptep) \ | ||
139 | do { \ | ||
140 | tlb->need_flush = 1; \ | ||
141 | __pte_free_tlb(tlb, ptep); \ | ||
142 | } while (0) | ||
143 | |||
144 | #ifndef __ARCH_HAS_4LEVEL_HACK | ||
145 | #define pud_free_tlb(tlb, pudp) \ | ||
146 | do { \ | ||
147 | tlb->need_flush = 1; \ | ||
148 | __pud_free_tlb(tlb, pudp); \ | ||
149 | } while (0) | ||
150 | #endif | ||
151 | |||
152 | #define pmd_free_tlb(tlb, pmdp) \ | ||
153 | do { \ | ||
154 | tlb->need_flush = 1; \ | ||
155 | __pmd_free_tlb(tlb, pmdp); \ | ||
156 | } while (0) | ||
157 | |||
158 | #define tlb_migrate_finish(mm) do {} while (0) | ||
159 | |||
160 | #endif /* _ASM_GENERIC__TLB_H */ | ||