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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 | ||
21 | void *kmap(struct page *page) | |
22 | { | |
23 | might_sleep(); | |
24 | if (!PageHighMem(page)) | |
25 | return page_address(page); | |
26 | return kmap_high(page); | |
27 | } | |
28 | EXPORT_SYMBOL(kmap); | |
29 | ||
30 | void kunmap(struct page *page) | |
31 | { | |
32 | BUG_ON(in_interrupt()); | |
33 | if (!PageHighMem(page)) | |
34 | return; | |
35 | kunmap_high(page); | |
36 | } | |
37 | EXPORT_SYMBOL(kunmap); | |
38 | ||
3e4d3af5 | 39 | void *__kmap_atomic(struct page *page) |
d73cd428 NP |
40 | { |
41 | unsigned int idx; | |
42 | unsigned long vaddr; | |
7929eb9c | 43 | void *kmap; |
3e4d3af5 | 44 | int type; |
d73cd428 NP |
45 | |
46 | pagefault_disable(); | |
47 | if (!PageHighMem(page)) | |
48 | return page_address(page); | |
49 | ||
17ebba1f NP |
50 | #ifdef CONFIG_DEBUG_HIGHMEM |
51 | /* | |
52 | * There is no cache coherency issue when non VIVT, so force the | |
53 | * dedicated kmap usage for better debugging purposes in that case. | |
54 | */ | |
55 | if (!cache_is_vivt()) | |
56 | kmap = NULL; | |
57 | else | |
58 | #endif | |
59 | kmap = kmap_high_get(page); | |
7929eb9c NP |
60 | if (kmap) |
61 | return kmap; | |
62 | ||
3e4d3af5 PZ |
63 | type = kmap_atomic_idx_push(); |
64 | ||
d73cd428 NP |
65 | idx = type + KM_TYPE_NR * smp_processor_id(); |
66 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); | |
67 | #ifdef CONFIG_DEBUG_HIGHMEM | |
68 | /* | |
69 | * With debugging enabled, kunmap_atomic forces that entry to 0. | |
70 | * Make sure it was indeed properly unmapped. | |
71 | */ | |
72 | BUG_ON(!pte_none(*(TOP_PTE(vaddr)))); | |
73 | #endif | |
74 | set_pte_ext(TOP_PTE(vaddr), mk_pte(page, kmap_prot), 0); | |
75 | /* | |
76 | * When debugging is off, kunmap_atomic leaves the previous mapping | |
77 | * in place, so this TLB flush ensures the TLB is updated with the | |
78 | * new mapping. | |
79 | */ | |
80 | local_flush_tlb_kernel_page(vaddr); | |
81 | ||
82 | return (void *)vaddr; | |
83 | } | |
3e4d3af5 | 84 | EXPORT_SYMBOL(__kmap_atomic); |
d73cd428 | 85 | |
3e4d3af5 | 86 | void __kunmap_atomic(void *kvaddr) |
d73cd428 NP |
87 | { |
88 | unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; | |
3e4d3af5 | 89 | int idx, type; |
d73cd428 NP |
90 | |
91 | if (kvaddr >= (void *)FIXADDR_START) { | |
20273941 | 92 | type = kmap_atomic_idx(); |
3e4d3af5 PZ |
93 | idx = type + KM_TYPE_NR * smp_processor_id(); |
94 | ||
7e5a69e8 NP |
95 | if (cache_is_vivt()) |
96 | __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); | |
d73cd428 NP |
97 | #ifdef CONFIG_DEBUG_HIGHMEM |
98 | BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); | |
99 | set_pte_ext(TOP_PTE(vaddr), __pte(0), 0); | |
100 | local_flush_tlb_kernel_page(vaddr); | |
101 | #else | |
102 | (void) idx; /* to kill a warning */ | |
103 | #endif | |
20273941 | 104 | kmap_atomic_idx_pop(); |
7929eb9c NP |
105 | } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { |
106 | /* this address was obtained through kmap_high_get() */ | |
107 | kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); | |
d73cd428 NP |
108 | } |
109 | pagefault_enable(); | |
110 | } | |
3e4d3af5 | 111 | EXPORT_SYMBOL(__kunmap_atomic); |
d73cd428 | 112 | |
3e4d3af5 | 113 | void *kmap_atomic_pfn(unsigned long pfn) |
d73cd428 | 114 | { |
d73cd428 | 115 | unsigned long vaddr; |
3e4d3af5 | 116 | int idx, type; |
d73cd428 NP |
117 | |
118 | pagefault_disable(); | |
119 | ||
3e4d3af5 | 120 | type = kmap_atomic_idx_push(); |
d73cd428 NP |
121 | idx = type + KM_TYPE_NR * smp_processor_id(); |
122 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); | |
123 | #ifdef CONFIG_DEBUG_HIGHMEM | |
124 | BUG_ON(!pte_none(*(TOP_PTE(vaddr)))); | |
125 | #endif | |
126 | set_pte_ext(TOP_PTE(vaddr), pfn_pte(pfn, kmap_prot), 0); | |
127 | local_flush_tlb_kernel_page(vaddr); | |
128 | ||
129 | return (void *)vaddr; | |
130 | } | |
131 | ||
132 | struct page *kmap_atomic_to_page(const void *ptr) | |
133 | { | |
134 | unsigned long vaddr = (unsigned long)ptr; | |
135 | pte_t *pte; | |
136 | ||
137 | if (vaddr < FIXADDR_START) | |
138 | return virt_to_page(ptr); | |
139 | ||
140 | pte = TOP_PTE(vaddr); | |
141 | return pte_page(*pte); | |
142 | } |