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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> | |
41e94a85 | 17 | #include <linux/memory_hotplug.h> |
92281dee DW |
18 | |
19 | #ifndef ioremap_cache | |
20 | /* temporary while we convert existing ioremap_cache users to memremap */ | |
21 | __weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size) | |
22 | { | |
23 | return ioremap(offset, size); | |
24 | } | |
25 | #endif | |
26 | ||
182475b7 DW |
27 | static void *try_ram_remap(resource_size_t offset, size_t size) |
28 | { | |
29 | struct page *page = pfn_to_page(offset >> PAGE_SHIFT); | |
30 | ||
31 | /* In the simple case just return the existing linear address */ | |
32 | if (!PageHighMem(page)) | |
33 | return __va(offset); | |
34 | return NULL; /* fallback to ioremap_cache */ | |
35 | } | |
36 | ||
92281dee DW |
37 | /** |
38 | * memremap() - remap an iomem_resource as cacheable memory | |
39 | * @offset: iomem resource start address | |
40 | * @size: size of remap | |
41 | * @flags: either MEMREMAP_WB or MEMREMAP_WT | |
42 | * | |
43 | * memremap() is "ioremap" for cases where it is known that the resource | |
44 | * being mapped does not have i/o side effects and the __iomem | |
45 | * annotation is not applicable. | |
46 | * | |
47 | * MEMREMAP_WB - matches the default mapping for "System RAM" on | |
48 | * the architecture. This is usually a read-allocate write-back cache. | |
49 | * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM | |
50 | * memremap() will bypass establishing a new mapping and instead return | |
51 | * a pointer into the direct map. | |
52 | * | |
53 | * MEMREMAP_WT - establish a mapping whereby writes either bypass the | |
54 | * cache or are written through to memory and never exist in a | |
55 | * cache-dirty state with respect to program visibility. Attempts to | |
56 | * map "System RAM" with this mapping type will fail. | |
57 | */ | |
58 | void *memremap(resource_size_t offset, size_t size, unsigned long flags) | |
59 | { | |
60 | int is_ram = region_intersects(offset, size, "System RAM"); | |
61 | void *addr = NULL; | |
62 | ||
63 | if (is_ram == REGION_MIXED) { | |
64 | WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n", | |
65 | &offset, (unsigned long) size); | |
66 | return NULL; | |
67 | } | |
68 | ||
69 | /* Try all mapping types requested until one returns non-NULL */ | |
70 | if (flags & MEMREMAP_WB) { | |
71 | flags &= ~MEMREMAP_WB; | |
72 | /* | |
73 | * MEMREMAP_WB is special in that it can be satisifed | |
74 | * from the direct map. Some archs depend on the | |
75 | * capability of memremap() to autodetect cases where | |
76 | * the requested range is potentially in "System RAM" | |
77 | */ | |
78 | if (is_ram == REGION_INTERSECTS) | |
182475b7 DW |
79 | addr = try_ram_remap(offset, size); |
80 | if (!addr) | |
92281dee DW |
81 | addr = ioremap_cache(offset, size); |
82 | } | |
83 | ||
84 | /* | |
85 | * If we don't have a mapping yet and more request flags are | |
86 | * pending then we will be attempting to establish a new virtual | |
87 | * address mapping. Enforce that this mapping is not aliasing | |
88 | * "System RAM" | |
89 | */ | |
90 | if (!addr && is_ram == REGION_INTERSECTS && flags) { | |
91 | WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n", | |
92 | &offset, (unsigned long) size); | |
93 | return NULL; | |
94 | } | |
95 | ||
96 | if (!addr && (flags & MEMREMAP_WT)) { | |
97 | flags &= ~MEMREMAP_WT; | |
98 | addr = ioremap_wt(offset, size); | |
99 | } | |
100 | ||
101 | return addr; | |
102 | } | |
103 | EXPORT_SYMBOL(memremap); | |
104 | ||
105 | void memunmap(void *addr) | |
106 | { | |
107 | if (is_vmalloc_addr(addr)) | |
108 | iounmap((void __iomem *) addr); | |
109 | } | |
110 | EXPORT_SYMBOL(memunmap); | |
7d3dcf26 CH |
111 | |
112 | static void devm_memremap_release(struct device *dev, void *res) | |
113 | { | |
114 | memunmap(res); | |
115 | } | |
116 | ||
117 | static int devm_memremap_match(struct device *dev, void *res, void *match_data) | |
118 | { | |
119 | return *(void **)res == match_data; | |
120 | } | |
121 | ||
122 | void *devm_memremap(struct device *dev, resource_size_t offset, | |
123 | size_t size, unsigned long flags) | |
124 | { | |
125 | void **ptr, *addr; | |
126 | ||
538ea4aa DW |
127 | ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL, |
128 | dev_to_node(dev)); | |
7d3dcf26 | 129 | if (!ptr) |
b36f4761 | 130 | return ERR_PTR(-ENOMEM); |
7d3dcf26 CH |
131 | |
132 | addr = memremap(offset, size, flags); | |
133 | if (addr) { | |
134 | *ptr = addr; | |
135 | devres_add(dev, ptr); | |
136 | } else | |
137 | devres_free(ptr); | |
138 | ||
139 | return addr; | |
140 | } | |
141 | EXPORT_SYMBOL(devm_memremap); | |
142 | ||
143 | void devm_memunmap(struct device *dev, void *addr) | |
144 | { | |
d741314f DW |
145 | WARN_ON(devres_release(dev, devm_memremap_release, |
146 | devm_memremap_match, addr)); | |
7d3dcf26 CH |
147 | } |
148 | EXPORT_SYMBOL(devm_memunmap); | |
41e94a85 CH |
149 | |
150 | #ifdef CONFIG_ZONE_DEVICE | |
151 | struct page_map { | |
152 | struct resource res; | |
153 | }; | |
154 | ||
155 | static void devm_memremap_pages_release(struct device *dev, void *res) | |
156 | { | |
157 | struct page_map *page_map = res; | |
158 | ||
159 | /* pages are dead and unused, undo the arch mapping */ | |
160 | arch_remove_memory(page_map->res.start, resource_size(&page_map->res)); | |
161 | } | |
162 | ||
163 | void *devm_memremap_pages(struct device *dev, struct resource *res) | |
164 | { | |
165 | int is_ram = region_intersects(res->start, resource_size(res), | |
166 | "System RAM"); | |
167 | struct page_map *page_map; | |
168 | int error, nid; | |
169 | ||
170 | if (is_ram == REGION_MIXED) { | |
171 | WARN_ONCE(1, "%s attempted on mixed region %pr\n", | |
172 | __func__, res); | |
173 | return ERR_PTR(-ENXIO); | |
174 | } | |
175 | ||
176 | if (is_ram == REGION_INTERSECTS) | |
177 | return __va(res->start); | |
178 | ||
538ea4aa DW |
179 | page_map = devres_alloc_node(devm_memremap_pages_release, |
180 | sizeof(*page_map), GFP_KERNEL, dev_to_node(dev)); | |
41e94a85 CH |
181 | if (!page_map) |
182 | return ERR_PTR(-ENOMEM); | |
183 | ||
184 | memcpy(&page_map->res, res, sizeof(*res)); | |
185 | ||
186 | nid = dev_to_node(dev); | |
187 | if (nid < 0) | |
7eff93b7 | 188 | nid = numa_mem_id(); |
41e94a85 CH |
189 | |
190 | error = arch_add_memory(nid, res->start, resource_size(res), true); | |
191 | if (error) { | |
192 | devres_free(page_map); | |
193 | return ERR_PTR(error); | |
194 | } | |
195 | ||
196 | devres_add(dev, page_map); | |
197 | return __va(res->start); | |
198 | } | |
199 | EXPORT_SYMBOL(devm_memremap_pages); | |
200 | #endif /* CONFIG_ZONE_DEVICE */ |