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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 | ||
39 | void *kmap_atomic(struct page *page, enum km_type type) | |
40 | { | |
41 | unsigned int idx; | |
42 | unsigned long vaddr; | |
7929eb9c | 43 | void *kmap; |
d73cd428 NP |
44 | |
45 | pagefault_disable(); | |
46 | if (!PageHighMem(page)) | |
47 | return page_address(page); | |
48 | ||
7929eb9c NP |
49 | kmap = kmap_high_get(page); |
50 | if (kmap) | |
51 | return kmap; | |
52 | ||
d73cd428 NP |
53 | idx = type + KM_TYPE_NR * smp_processor_id(); |
54 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); | |
55 | #ifdef CONFIG_DEBUG_HIGHMEM | |
56 | /* | |
57 | * With debugging enabled, kunmap_atomic forces that entry to 0. | |
58 | * Make sure it was indeed properly unmapped. | |
59 | */ | |
60 | BUG_ON(!pte_none(*(TOP_PTE(vaddr)))); | |
61 | #endif | |
62 | set_pte_ext(TOP_PTE(vaddr), mk_pte(page, kmap_prot), 0); | |
63 | /* | |
64 | * When debugging is off, kunmap_atomic leaves the previous mapping | |
65 | * in place, so this TLB flush ensures the TLB is updated with the | |
66 | * new mapping. | |
67 | */ | |
68 | local_flush_tlb_kernel_page(vaddr); | |
69 | ||
70 | return (void *)vaddr; | |
71 | } | |
72 | EXPORT_SYMBOL(kmap_atomic); | |
73 | ||
74 | void kunmap_atomic(void *kvaddr, enum km_type type) | |
75 | { | |
76 | unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; | |
77 | unsigned int idx = type + KM_TYPE_NR * smp_processor_id(); | |
78 | ||
79 | if (kvaddr >= (void *)FIXADDR_START) { | |
80 | __cpuc_flush_dcache_page((void *)vaddr); | |
81 | #ifdef CONFIG_DEBUG_HIGHMEM | |
82 | BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); | |
83 | set_pte_ext(TOP_PTE(vaddr), __pte(0), 0); | |
84 | local_flush_tlb_kernel_page(vaddr); | |
85 | #else | |
86 | (void) idx; /* to kill a warning */ | |
87 | #endif | |
7929eb9c NP |
88 | } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { |
89 | /* this address was obtained through kmap_high_get() */ | |
90 | kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); | |
d73cd428 NP |
91 | } |
92 | pagefault_enable(); | |
93 | } | |
94 | EXPORT_SYMBOL(kunmap_atomic); | |
95 | ||
96 | void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) | |
97 | { | |
98 | unsigned int idx; | |
99 | unsigned long vaddr; | |
100 | ||
101 | pagefault_disable(); | |
102 | ||
103 | idx = type + KM_TYPE_NR * smp_processor_id(); | |
104 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); | |
105 | #ifdef CONFIG_DEBUG_HIGHMEM | |
106 | BUG_ON(!pte_none(*(TOP_PTE(vaddr)))); | |
107 | #endif | |
108 | set_pte_ext(TOP_PTE(vaddr), pfn_pte(pfn, kmap_prot), 0); | |
109 | local_flush_tlb_kernel_page(vaddr); | |
110 | ||
111 | return (void *)vaddr; | |
112 | } | |
113 | ||
114 | struct page *kmap_atomic_to_page(const void *ptr) | |
115 | { | |
116 | unsigned long vaddr = (unsigned long)ptr; | |
117 | pte_t *pte; | |
118 | ||
119 | if (vaddr < FIXADDR_START) | |
120 | return virt_to_page(ptr); | |
121 | ||
122 | pte = TOP_PTE(vaddr); | |
123 | return pte_page(*pte); | |
124 | } |