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b478491f DH |
1 | /* Invalidate icache when dcache doesn't need invalidation as it's in |
2 | * write-through mode | |
3 | * | |
4 | * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public Licence | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the Licence, or (at your option) any later version. | |
11 | */ | |
12 | #include <linux/module.h> | |
13 | #include <linux/mm.h> | |
14 | #include <asm/cacheflush.h> | |
8be06289 AT |
15 | #include <asm/smp.h> |
16 | #include "cache-smp.h" | |
b478491f DH |
17 | |
18 | /** | |
19 | * flush_icache_page_range - Flush dcache and invalidate icache for part of a | |
20 | * single page | |
21 | * @start: The starting virtual address of the page part. | |
22 | * @end: The ending virtual address of the page part. | |
23 | * | |
24 | * Invalidate the icache for part of a single page, as determined by the | |
25 | * virtual addresses given. The page must be in the paged area. The dcache is | |
26 | * not flushed as the cache must be in write-through mode to get here. | |
27 | */ | |
28 | static void flush_icache_page_range(unsigned long start, unsigned long end) | |
29 | { | |
30 | unsigned long addr, size, off; | |
31 | struct page *page; | |
32 | pgd_t *pgd; | |
33 | pud_t *pud; | |
34 | pmd_t *pmd; | |
35 | pte_t *ppte, pte; | |
36 | ||
37 | /* work out how much of the page to flush */ | |
38 | off = start & ~PAGE_MASK; | |
39 | size = end - start; | |
40 | ||
41 | /* get the physical address the page is mapped to from the page | |
42 | * tables */ | |
43 | pgd = pgd_offset(current->mm, start); | |
44 | if (!pgd || !pgd_val(*pgd)) | |
45 | return; | |
46 | ||
47 | pud = pud_offset(pgd, start); | |
48 | if (!pud || !pud_val(*pud)) | |
49 | return; | |
50 | ||
51 | pmd = pmd_offset(pud, start); | |
52 | if (!pmd || !pmd_val(*pmd)) | |
53 | return; | |
54 | ||
55 | ppte = pte_offset_map(pmd, start); | |
56 | if (!ppte) | |
57 | return; | |
58 | pte = *ppte; | |
59 | pte_unmap(ppte); | |
60 | ||
61 | if (pte_none(pte)) | |
62 | return; | |
63 | ||
64 | page = pte_page(pte); | |
65 | if (!page) | |
66 | return; | |
67 | ||
68 | addr = page_to_phys(page); | |
69 | ||
70 | /* invalidate the icache coverage on that region */ | |
8be06289 AT |
71 | mn10300_local_icache_inv_range2(addr + off, size); |
72 | smp_cache_call(SMP_ICACHE_INV_FLUSH_RANGE, start, end); | |
b478491f DH |
73 | } |
74 | ||
75 | /** | |
76 | * flush_icache_range - Globally flush dcache and invalidate icache for region | |
77 | * @start: The starting virtual address of the region. | |
78 | * @end: The ending virtual address of the region. | |
79 | * | |
80 | * This is used by the kernel to globally flush some code it has just written | |
81 | * from the dcache back to RAM and then to globally invalidate the icache over | |
82 | * that region so that that code can be run on all CPUs in the system. | |
83 | */ | |
84 | void flush_icache_range(unsigned long start, unsigned long end) | |
85 | { | |
86 | unsigned long start_page, end_page; | |
8be06289 AT |
87 | unsigned long flags; |
88 | ||
89 | flags = smp_lock_cache(); | |
b478491f DH |
90 | |
91 | if (end > 0x80000000UL) { | |
92 | /* addresses above 0xa0000000 do not go through the cache */ | |
93 | if (end > 0xa0000000UL) { | |
94 | end = 0xa0000000UL; | |
95 | if (start >= end) | |
8be06289 | 96 | goto done; |
b478491f DH |
97 | } |
98 | ||
99 | /* kernel addresses between 0x80000000 and 0x9fffffff do not | |
100 | * require page tables, so we just map such addresses | |
101 | * directly */ | |
102 | start_page = (start >= 0x80000000UL) ? start : 0x80000000UL; | |
b478491f | 103 | mn10300_icache_inv_range(start_page, end); |
8be06289 | 104 | smp_cache_call(SMP_ICACHE_INV_FLUSH_RANGE, start, end); |
b478491f | 105 | if (start_page == start) |
8be06289 | 106 | goto done; |
b478491f DH |
107 | end = start_page; |
108 | } | |
109 | ||
110 | start_page = start & PAGE_MASK; | |
8be06289 | 111 | end_page = (end - 1) & PAGE_MASK; |
b478491f DH |
112 | |
113 | if (start_page == end_page) { | |
114 | /* the first and last bytes are on the same page */ | |
115 | flush_icache_page_range(start, end); | |
116 | } else if (start_page + 1 == end_page) { | |
117 | /* split over two virtually contiguous pages */ | |
118 | flush_icache_page_range(start, end_page); | |
119 | flush_icache_page_range(end_page, end); | |
120 | } else { | |
121 | /* more than 2 pages; just flush the entire cache */ | |
8be06289 AT |
122 | mn10300_local_icache_inv(); |
123 | smp_cache_call(SMP_ICACHE_INV, 0, 0); | |
b478491f | 124 | } |
8be06289 AT |
125 | |
126 | done: | |
127 | smp_unlock_cache(flags); | |
b478491f DH |
128 | } |
129 | EXPORT_SYMBOL(flush_icache_range); |