Commit | Line | Data |
---|---|---|
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 | ||
a24401bc | 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 | 65 | idx = type + KM_TYPE_NR * smp_processor_id(); |
4221e2e6 | 66 | vaddr = __fix_to_virt(idx); |
d73cd428 NP |
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 | */ | |
0d31fe47 | 72 | BUG_ON(!pte_none(get_top_pte(vaddr))); |
d73cd428 | 73 | #endif |
d73cd428 NP |
74 | /* |
75 | * When debugging is off, kunmap_atomic leaves the previous mapping | |
67ece144 RK |
76 | * in place, so the contained TLB flush ensures the TLB is updated |
77 | * with the new mapping. | |
d73cd428 | 78 | */ |
67ece144 | 79 | set_top_pte(vaddr, mk_pte(page, kmap_prot)); |
d73cd428 NP |
80 | |
81 | return (void *)vaddr; | |
82 | } | |
a24401bc | 83 | EXPORT_SYMBOL(kmap_atomic); |
d73cd428 | 84 | |
3e4d3af5 | 85 | void __kunmap_atomic(void *kvaddr) |
d73cd428 NP |
86 | { |
87 | unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; | |
3e4d3af5 | 88 | int idx, type; |
d73cd428 NP |
89 | |
90 | if (kvaddr >= (void *)FIXADDR_START) { | |
20273941 | 91 | type = kmap_atomic_idx(); |
3e4d3af5 PZ |
92 | idx = type + KM_TYPE_NR * smp_processor_id(); |
93 | ||
7e5a69e8 NP |
94 | if (cache_is_vivt()) |
95 | __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); | |
d73cd428 | 96 | #ifdef CONFIG_DEBUG_HIGHMEM |
4221e2e6 | 97 | BUG_ON(vaddr != __fix_to_virt(idx)); |
67ece144 | 98 | set_top_pte(vaddr, __pte(0)); |
d73cd428 NP |
99 | #else |
100 | (void) idx; /* to kill a warning */ | |
101 | #endif | |
20273941 | 102 | kmap_atomic_idx_pop(); |
7929eb9c NP |
103 | } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { |
104 | /* this address was obtained through kmap_high_get() */ | |
105 | kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); | |
d73cd428 NP |
106 | } |
107 | pagefault_enable(); | |
108 | } | |
3e4d3af5 | 109 | EXPORT_SYMBOL(__kunmap_atomic); |
d73cd428 | 110 | |
3e4d3af5 | 111 | void *kmap_atomic_pfn(unsigned long pfn) |
d73cd428 | 112 | { |
d73cd428 | 113 | unsigned long vaddr; |
3e4d3af5 | 114 | int idx, type; |
d73cd428 NP |
115 | |
116 | pagefault_disable(); | |
117 | ||
3e4d3af5 | 118 | type = kmap_atomic_idx_push(); |
d73cd428 | 119 | idx = type + KM_TYPE_NR * smp_processor_id(); |
4221e2e6 | 120 | vaddr = __fix_to_virt(idx); |
d73cd428 | 121 | #ifdef CONFIG_DEBUG_HIGHMEM |
0d31fe47 | 122 | BUG_ON(!pte_none(get_top_pte(vaddr))); |
d73cd428 | 123 | #endif |
67ece144 | 124 | set_top_pte(vaddr, pfn_pte(pfn, kmap_prot)); |
d73cd428 NP |
125 | |
126 | return (void *)vaddr; | |
127 | } | |
128 | ||
129 | struct page *kmap_atomic_to_page(const void *ptr) | |
130 | { | |
131 | unsigned long vaddr = (unsigned long)ptr; | |
d73cd428 NP |
132 | |
133 | if (vaddr < FIXADDR_START) | |
134 | return virt_to_page(ptr); | |
135 | ||
0d31fe47 | 136 | return pte_page(get_top_pte(vaddr)); |
d73cd428 | 137 | } |