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92281dee DW |
1 | /* |
2 | * Copyright(c) 2015 Intel Corporation. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of version 2 of the GNU General Public License as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | */ | |
7d3dcf26 | 13 | #include <linux/device.h> |
92281dee DW |
14 | #include <linux/types.h> |
15 | #include <linux/io.h> | |
16 | #include <linux/mm.h> | |
17 | ||
18 | #ifndef ioremap_cache | |
19 | /* temporary while we convert existing ioremap_cache users to memremap */ | |
20 | __weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size) | |
21 | { | |
22 | return ioremap(offset, size); | |
23 | } | |
24 | #endif | |
25 | ||
26 | /** | |
27 | * memremap() - remap an iomem_resource as cacheable memory | |
28 | * @offset: iomem resource start address | |
29 | * @size: size of remap | |
30 | * @flags: either MEMREMAP_WB or MEMREMAP_WT | |
31 | * | |
32 | * memremap() is "ioremap" for cases where it is known that the resource | |
33 | * being mapped does not have i/o side effects and the __iomem | |
34 | * annotation is not applicable. | |
35 | * | |
36 | * MEMREMAP_WB - matches the default mapping for "System RAM" on | |
37 | * the architecture. This is usually a read-allocate write-back cache. | |
38 | * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM | |
39 | * memremap() will bypass establishing a new mapping and instead return | |
40 | * a pointer into the direct map. | |
41 | * | |
42 | * MEMREMAP_WT - establish a mapping whereby writes either bypass the | |
43 | * cache or are written through to memory and never exist in a | |
44 | * cache-dirty state with respect to program visibility. Attempts to | |
45 | * map "System RAM" with this mapping type will fail. | |
46 | */ | |
47 | void *memremap(resource_size_t offset, size_t size, unsigned long flags) | |
48 | { | |
49 | int is_ram = region_intersects(offset, size, "System RAM"); | |
50 | void *addr = NULL; | |
51 | ||
52 | if (is_ram == REGION_MIXED) { | |
53 | WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n", | |
54 | &offset, (unsigned long) size); | |
55 | return NULL; | |
56 | } | |
57 | ||
58 | /* Try all mapping types requested until one returns non-NULL */ | |
59 | if (flags & MEMREMAP_WB) { | |
60 | flags &= ~MEMREMAP_WB; | |
61 | /* | |
62 | * MEMREMAP_WB is special in that it can be satisifed | |
63 | * from the direct map. Some archs depend on the | |
64 | * capability of memremap() to autodetect cases where | |
65 | * the requested range is potentially in "System RAM" | |
66 | */ | |
67 | if (is_ram == REGION_INTERSECTS) | |
68 | addr = __va(offset); | |
69 | else | |
70 | addr = ioremap_cache(offset, size); | |
71 | } | |
72 | ||
73 | /* | |
74 | * If we don't have a mapping yet and more request flags are | |
75 | * pending then we will be attempting to establish a new virtual | |
76 | * address mapping. Enforce that this mapping is not aliasing | |
77 | * "System RAM" | |
78 | */ | |
79 | if (!addr && is_ram == REGION_INTERSECTS && flags) { | |
80 | WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n", | |
81 | &offset, (unsigned long) size); | |
82 | return NULL; | |
83 | } | |
84 | ||
85 | if (!addr && (flags & MEMREMAP_WT)) { | |
86 | flags &= ~MEMREMAP_WT; | |
87 | addr = ioremap_wt(offset, size); | |
88 | } | |
89 | ||
90 | return addr; | |
91 | } | |
92 | EXPORT_SYMBOL(memremap); | |
93 | ||
94 | void memunmap(void *addr) | |
95 | { | |
96 | if (is_vmalloc_addr(addr)) | |
97 | iounmap((void __iomem *) addr); | |
98 | } | |
99 | EXPORT_SYMBOL(memunmap); | |
7d3dcf26 CH |
100 | |
101 | static void devm_memremap_release(struct device *dev, void *res) | |
102 | { | |
103 | memunmap(res); | |
104 | } | |
105 | ||
106 | static int devm_memremap_match(struct device *dev, void *res, void *match_data) | |
107 | { | |
108 | return *(void **)res == match_data; | |
109 | } | |
110 | ||
111 | void *devm_memremap(struct device *dev, resource_size_t offset, | |
112 | size_t size, unsigned long flags) | |
113 | { | |
114 | void **ptr, *addr; | |
115 | ||
116 | ptr = devres_alloc(devm_memremap_release, sizeof(*ptr), GFP_KERNEL); | |
117 | if (!ptr) | |
118 | return NULL; | |
119 | ||
120 | addr = memremap(offset, size, flags); | |
121 | if (addr) { | |
122 | *ptr = addr; | |
123 | devres_add(dev, ptr); | |
124 | } else | |
125 | devres_free(ptr); | |
126 | ||
127 | return addr; | |
128 | } | |
129 | EXPORT_SYMBOL(devm_memremap); | |
130 | ||
131 | void devm_memunmap(struct device *dev, void *addr) | |
132 | { | |
133 | WARN_ON(devres_destroy(dev, devm_memremap_release, devm_memremap_match, | |
134 | addr)); | |
135 | memunmap(addr); | |
136 | } | |
137 | EXPORT_SYMBOL(devm_memunmap); |