Commit | Line | Data |
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d73cd428 NP |
1 | /* |
2 | * arch/arm/mm/highmem.c -- ARM highmem support | |
3 | * | |
4 | * Author: Nicolas Pitre | |
5 | * Created: september 8, 2008 | |
6 | * Copyright: Marvell Semiconductors Inc. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/highmem.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <asm/fixmap.h> | |
17 | #include <asm/cacheflush.h> | |
18 | #include <asm/tlbflush.h> | |
19 | #include "mm.h" | |
20 | ||
a05e54c1 LH |
21 | pte_t *fixmap_page_table; |
22 | ||
23 | static inline void set_fixmap_pte(int idx, pte_t pte) | |
24 | { | |
25 | unsigned long vaddr = __fix_to_virt(idx); | |
26 | set_pte_ext(fixmap_page_table + idx, pte, 0); | |
27 | local_flush_tlb_kernel_page(vaddr); | |
28 | } | |
29 | ||
30 | static inline pte_t get_fixmap_pte(unsigned long vaddr) | |
31 | { | |
32 | unsigned long idx = __virt_to_fix(vaddr); | |
33 | return *(fixmap_page_table + idx); | |
34 | } | |
35 | ||
d73cd428 NP |
36 | void *kmap(struct page *page) |
37 | { | |
38 | might_sleep(); | |
39 | if (!PageHighMem(page)) | |
40 | return page_address(page); | |
41 | return kmap_high(page); | |
42 | } | |
43 | EXPORT_SYMBOL(kmap); | |
44 | ||
45 | void kunmap(struct page *page) | |
46 | { | |
47 | BUG_ON(in_interrupt()); | |
48 | if (!PageHighMem(page)) | |
49 | return; | |
50 | kunmap_high(page); | |
51 | } | |
52 | EXPORT_SYMBOL(kunmap); | |
53 | ||
a24401bc | 54 | void *kmap_atomic(struct page *page) |
d73cd428 NP |
55 | { |
56 | unsigned int idx; | |
57 | unsigned long vaddr; | |
7929eb9c | 58 | void *kmap; |
3e4d3af5 | 59 | int type; |
d73cd428 NP |
60 | |
61 | pagefault_disable(); | |
62 | if (!PageHighMem(page)) | |
63 | return page_address(page); | |
64 | ||
17ebba1f NP |
65 | #ifdef CONFIG_DEBUG_HIGHMEM |
66 | /* | |
67 | * There is no cache coherency issue when non VIVT, so force the | |
68 | * dedicated kmap usage for better debugging purposes in that case. | |
69 | */ | |
70 | if (!cache_is_vivt()) | |
71 | kmap = NULL; | |
72 | else | |
73 | #endif | |
74 | kmap = kmap_high_get(page); | |
7929eb9c NP |
75 | if (kmap) |
76 | return kmap; | |
77 | ||
3e4d3af5 PZ |
78 | type = kmap_atomic_idx_push(); |
79 | ||
d73cd428 | 80 | idx = type + KM_TYPE_NR * smp_processor_id(); |
4221e2e6 | 81 | vaddr = __fix_to_virt(idx); |
d73cd428 NP |
82 | #ifdef CONFIG_DEBUG_HIGHMEM |
83 | /* | |
84 | * With debugging enabled, kunmap_atomic forces that entry to 0. | |
85 | * Make sure it was indeed properly unmapped. | |
86 | */ | |
a05e54c1 | 87 | BUG_ON(!pte_none(*(fixmap_page_table + idx))); |
d73cd428 | 88 | #endif |
d73cd428 NP |
89 | /* |
90 | * When debugging is off, kunmap_atomic leaves the previous mapping | |
67ece144 RK |
91 | * in place, so the contained TLB flush ensures the TLB is updated |
92 | * with the new mapping. | |
d73cd428 | 93 | */ |
a05e54c1 | 94 | set_fixmap_pte(idx, mk_pte(page, kmap_prot)); |
d73cd428 NP |
95 | |
96 | return (void *)vaddr; | |
97 | } | |
a24401bc | 98 | EXPORT_SYMBOL(kmap_atomic); |
d73cd428 | 99 | |
3e4d3af5 | 100 | void __kunmap_atomic(void *kvaddr) |
d73cd428 NP |
101 | { |
102 | unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; | |
3e4d3af5 | 103 | int idx, type; |
d73cd428 NP |
104 | |
105 | if (kvaddr >= (void *)FIXADDR_START) { | |
20273941 | 106 | type = kmap_atomic_idx(); |
3e4d3af5 PZ |
107 | idx = type + KM_TYPE_NR * smp_processor_id(); |
108 | ||
7e5a69e8 NP |
109 | if (cache_is_vivt()) |
110 | __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); | |
d73cd428 | 111 | #ifdef CONFIG_DEBUG_HIGHMEM |
4221e2e6 | 112 | BUG_ON(vaddr != __fix_to_virt(idx)); |
a05e54c1 | 113 | set_fixmap_pte(idx, __pte(0)); |
d73cd428 NP |
114 | #else |
115 | (void) idx; /* to kill a warning */ | |
116 | #endif | |
20273941 | 117 | kmap_atomic_idx_pop(); |
7929eb9c NP |
118 | } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { |
119 | /* this address was obtained through kmap_high_get() */ | |
120 | kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); | |
d73cd428 NP |
121 | } |
122 | pagefault_enable(); | |
123 | } | |
3e4d3af5 | 124 | EXPORT_SYMBOL(__kunmap_atomic); |
d73cd428 | 125 | |
3e4d3af5 | 126 | void *kmap_atomic_pfn(unsigned long pfn) |
d73cd428 | 127 | { |
d73cd428 | 128 | unsigned long vaddr; |
3e4d3af5 | 129 | int idx, type; |
d73cd428 NP |
130 | |
131 | pagefault_disable(); | |
132 | ||
3e4d3af5 | 133 | type = kmap_atomic_idx_push(); |
d73cd428 | 134 | idx = type + KM_TYPE_NR * smp_processor_id(); |
4221e2e6 | 135 | vaddr = __fix_to_virt(idx); |
d73cd428 | 136 | #ifdef CONFIG_DEBUG_HIGHMEM |
a05e54c1 | 137 | BUG_ON(!pte_none(*(fixmap_page_table + idx))); |
d73cd428 | 138 | #endif |
a05e54c1 | 139 | set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot)); |
d73cd428 NP |
140 | |
141 | return (void *)vaddr; | |
142 | } | |
143 | ||
144 | struct page *kmap_atomic_to_page(const void *ptr) | |
145 | { | |
146 | unsigned long vaddr = (unsigned long)ptr; | |
d73cd428 NP |
147 | |
148 | if (vaddr < FIXADDR_START) | |
149 | return virt_to_page(ptr); | |
150 | ||
a05e54c1 | 151 | return pte_page(get_fixmap_pte(vaddr)); |
d73cd428 | 152 | } |