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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 | */ | |
9476df7d DW |
13 | #include <linux/radix-tree.h> |
14 | #include <linux/memremap.h> | |
7d3dcf26 | 15 | #include <linux/device.h> |
92281dee | 16 | #include <linux/types.h> |
34c0fd54 | 17 | #include <linux/pfn_t.h> |
92281dee DW |
18 | #include <linux/io.h> |
19 | #include <linux/mm.h> | |
41e94a85 | 20 | #include <linux/memory_hotplug.h> |
92281dee DW |
21 | |
22 | #ifndef ioremap_cache | |
23 | /* temporary while we convert existing ioremap_cache users to memremap */ | |
24 | __weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size) | |
25 | { | |
26 | return ioremap(offset, size); | |
27 | } | |
28 | #endif | |
29 | ||
182475b7 DW |
30 | static void *try_ram_remap(resource_size_t offset, size_t size) |
31 | { | |
32 | struct page *page = pfn_to_page(offset >> PAGE_SHIFT); | |
33 | ||
34 | /* In the simple case just return the existing linear address */ | |
35 | if (!PageHighMem(page)) | |
36 | return __va(offset); | |
37 | return NULL; /* fallback to ioremap_cache */ | |
38 | } | |
39 | ||
92281dee DW |
40 | /** |
41 | * memremap() - remap an iomem_resource as cacheable memory | |
42 | * @offset: iomem resource start address | |
43 | * @size: size of remap | |
44 | * @flags: either MEMREMAP_WB or MEMREMAP_WT | |
45 | * | |
46 | * memremap() is "ioremap" for cases where it is known that the resource | |
47 | * being mapped does not have i/o side effects and the __iomem | |
48 | * annotation is not applicable. | |
49 | * | |
50 | * MEMREMAP_WB - matches the default mapping for "System RAM" on | |
51 | * the architecture. This is usually a read-allocate write-back cache. | |
52 | * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM | |
53 | * memremap() will bypass establishing a new mapping and instead return | |
54 | * a pointer into the direct map. | |
55 | * | |
56 | * MEMREMAP_WT - establish a mapping whereby writes either bypass the | |
57 | * cache or are written through to memory and never exist in a | |
58 | * cache-dirty state with respect to program visibility. Attempts to | |
59 | * map "System RAM" with this mapping type will fail. | |
60 | */ | |
61 | void *memremap(resource_size_t offset, size_t size, unsigned long flags) | |
62 | { | |
63 | int is_ram = region_intersects(offset, size, "System RAM"); | |
64 | void *addr = NULL; | |
65 | ||
66 | if (is_ram == REGION_MIXED) { | |
67 | WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n", | |
68 | &offset, (unsigned long) size); | |
69 | return NULL; | |
70 | } | |
71 | ||
72 | /* Try all mapping types requested until one returns non-NULL */ | |
73 | if (flags & MEMREMAP_WB) { | |
74 | flags &= ~MEMREMAP_WB; | |
75 | /* | |
76 | * MEMREMAP_WB is special in that it can be satisifed | |
77 | * from the direct map. Some archs depend on the | |
78 | * capability of memremap() to autodetect cases where | |
79 | * the requested range is potentially in "System RAM" | |
80 | */ | |
81 | if (is_ram == REGION_INTERSECTS) | |
182475b7 DW |
82 | addr = try_ram_remap(offset, size); |
83 | if (!addr) | |
92281dee DW |
84 | addr = ioremap_cache(offset, size); |
85 | } | |
86 | ||
87 | /* | |
88 | * If we don't have a mapping yet and more request flags are | |
89 | * pending then we will be attempting to establish a new virtual | |
90 | * address mapping. Enforce that this mapping is not aliasing | |
91 | * "System RAM" | |
92 | */ | |
93 | if (!addr && is_ram == REGION_INTERSECTS && flags) { | |
94 | WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n", | |
95 | &offset, (unsigned long) size); | |
96 | return NULL; | |
97 | } | |
98 | ||
99 | if (!addr && (flags & MEMREMAP_WT)) { | |
100 | flags &= ~MEMREMAP_WT; | |
101 | addr = ioremap_wt(offset, size); | |
102 | } | |
103 | ||
104 | return addr; | |
105 | } | |
106 | EXPORT_SYMBOL(memremap); | |
107 | ||
108 | void memunmap(void *addr) | |
109 | { | |
110 | if (is_vmalloc_addr(addr)) | |
111 | iounmap((void __iomem *) addr); | |
112 | } | |
113 | EXPORT_SYMBOL(memunmap); | |
7d3dcf26 CH |
114 | |
115 | static void devm_memremap_release(struct device *dev, void *res) | |
116 | { | |
117 | memunmap(res); | |
118 | } | |
119 | ||
120 | static int devm_memremap_match(struct device *dev, void *res, void *match_data) | |
121 | { | |
122 | return *(void **)res == match_data; | |
123 | } | |
124 | ||
125 | void *devm_memremap(struct device *dev, resource_size_t offset, | |
126 | size_t size, unsigned long flags) | |
127 | { | |
128 | void **ptr, *addr; | |
129 | ||
538ea4aa DW |
130 | ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL, |
131 | dev_to_node(dev)); | |
7d3dcf26 | 132 | if (!ptr) |
b36f4761 | 133 | return ERR_PTR(-ENOMEM); |
7d3dcf26 CH |
134 | |
135 | addr = memremap(offset, size, flags); | |
136 | if (addr) { | |
137 | *ptr = addr; | |
138 | devres_add(dev, ptr); | |
139 | } else | |
140 | devres_free(ptr); | |
141 | ||
142 | return addr; | |
143 | } | |
144 | EXPORT_SYMBOL(devm_memremap); | |
145 | ||
146 | void devm_memunmap(struct device *dev, void *addr) | |
147 | { | |
d741314f DW |
148 | WARN_ON(devres_release(dev, devm_memremap_release, |
149 | devm_memremap_match, addr)); | |
7d3dcf26 CH |
150 | } |
151 | EXPORT_SYMBOL(devm_memunmap); | |
41e94a85 | 152 | |
34c0fd54 DW |
153 | pfn_t phys_to_pfn_t(dma_addr_t addr, unsigned long flags) |
154 | { | |
155 | return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags); | |
156 | } | |
157 | EXPORT_SYMBOL(phys_to_pfn_t); | |
158 | ||
41e94a85 | 159 | #ifdef CONFIG_ZONE_DEVICE |
9476df7d DW |
160 | static DEFINE_MUTEX(pgmap_lock); |
161 | static RADIX_TREE(pgmap_radix, GFP_KERNEL); | |
162 | #define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) | |
163 | #define SECTION_SIZE (1UL << PA_SECTION_SHIFT) | |
164 | ||
41e94a85 CH |
165 | struct page_map { |
166 | struct resource res; | |
9476df7d DW |
167 | struct percpu_ref *ref; |
168 | struct dev_pagemap pgmap; | |
41e94a85 CH |
169 | }; |
170 | ||
9476df7d DW |
171 | static void pgmap_radix_release(struct resource *res) |
172 | { | |
173 | resource_size_t key; | |
174 | ||
175 | mutex_lock(&pgmap_lock); | |
176 | for (key = res->start; key <= res->end; key += SECTION_SIZE) | |
177 | radix_tree_delete(&pgmap_radix, key >> PA_SECTION_SHIFT); | |
178 | mutex_unlock(&pgmap_lock); | |
179 | } | |
180 | ||
181 | static void devm_memremap_pages_release(struct device *dev, void *data) | |
41e94a85 | 182 | { |
9476df7d DW |
183 | struct page_map *page_map = data; |
184 | struct resource *res = &page_map->res; | |
185 | resource_size_t align_start, align_size; | |
186 | ||
187 | pgmap_radix_release(res); | |
41e94a85 CH |
188 | |
189 | /* pages are dead and unused, undo the arch mapping */ | |
9476df7d DW |
190 | align_start = res->start & ~(SECTION_SIZE - 1); |
191 | align_size = ALIGN(resource_size(res), SECTION_SIZE); | |
192 | arch_remove_memory(align_start, align_size); | |
193 | } | |
194 | ||
195 | /* assumes rcu_read_lock() held at entry */ | |
196 | struct dev_pagemap *find_dev_pagemap(resource_size_t phys) | |
197 | { | |
198 | struct page_map *page_map; | |
199 | ||
200 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
201 | ||
202 | page_map = radix_tree_lookup(&pgmap_radix, phys >> PA_SECTION_SHIFT); | |
203 | return page_map ? &page_map->pgmap : NULL; | |
41e94a85 CH |
204 | } |
205 | ||
206 | void *devm_memremap_pages(struct device *dev, struct resource *res) | |
207 | { | |
208 | int is_ram = region_intersects(res->start, resource_size(res), | |
209 | "System RAM"); | |
9476df7d | 210 | resource_size_t key, align_start, align_size; |
41e94a85 CH |
211 | struct page_map *page_map; |
212 | int error, nid; | |
213 | ||
214 | if (is_ram == REGION_MIXED) { | |
215 | WARN_ONCE(1, "%s attempted on mixed region %pr\n", | |
216 | __func__, res); | |
217 | return ERR_PTR(-ENXIO); | |
218 | } | |
219 | ||
220 | if (is_ram == REGION_INTERSECTS) | |
221 | return __va(res->start); | |
222 | ||
538ea4aa DW |
223 | page_map = devres_alloc_node(devm_memremap_pages_release, |
224 | sizeof(*page_map), GFP_KERNEL, dev_to_node(dev)); | |
41e94a85 CH |
225 | if (!page_map) |
226 | return ERR_PTR(-ENOMEM); | |
227 | ||
228 | memcpy(&page_map->res, res, sizeof(*res)); | |
229 | ||
9476df7d DW |
230 | page_map->pgmap.dev = dev; |
231 | mutex_lock(&pgmap_lock); | |
232 | error = 0; | |
233 | for (key = res->start; key <= res->end; key += SECTION_SIZE) { | |
234 | struct dev_pagemap *dup; | |
235 | ||
236 | rcu_read_lock(); | |
237 | dup = find_dev_pagemap(key); | |
238 | rcu_read_unlock(); | |
239 | if (dup) { | |
240 | dev_err(dev, "%s: %pr collides with mapping for %s\n", | |
241 | __func__, res, dev_name(dup->dev)); | |
242 | error = -EBUSY; | |
243 | break; | |
244 | } | |
245 | error = radix_tree_insert(&pgmap_radix, key >> PA_SECTION_SHIFT, | |
246 | page_map); | |
247 | if (error) { | |
248 | dev_err(dev, "%s: failed: %d\n", __func__, error); | |
249 | break; | |
250 | } | |
251 | } | |
252 | mutex_unlock(&pgmap_lock); | |
253 | if (error) | |
254 | goto err_radix; | |
255 | ||
41e94a85 CH |
256 | nid = dev_to_node(dev); |
257 | if (nid < 0) | |
7eff93b7 | 258 | nid = numa_mem_id(); |
41e94a85 | 259 | |
9476df7d DW |
260 | align_start = res->start & ~(SECTION_SIZE - 1); |
261 | align_size = ALIGN(resource_size(res), SECTION_SIZE); | |
262 | error = arch_add_memory(nid, align_start, align_size, true); | |
263 | if (error) | |
264 | goto err_add_memory; | |
41e94a85 CH |
265 | |
266 | devres_add(dev, page_map); | |
267 | return __va(res->start); | |
9476df7d DW |
268 | |
269 | err_add_memory: | |
270 | err_radix: | |
271 | pgmap_radix_release(res); | |
272 | devres_free(page_map); | |
273 | return ERR_PTR(error); | |
41e94a85 CH |
274 | } |
275 | EXPORT_SYMBOL(devm_memremap_pages); | |
276 | #endif /* CONFIG_ZONE_DEVICE */ |