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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; | |
4b94ffdc | 169 | struct vmem_altmap altmap; |
41e94a85 CH |
170 | }; |
171 | ||
3565fce3 DW |
172 | void get_zone_device_page(struct page *page) |
173 | { | |
174 | percpu_ref_get(page->pgmap->ref); | |
175 | } | |
176 | EXPORT_SYMBOL(get_zone_device_page); | |
177 | ||
178 | void put_zone_device_page(struct page *page) | |
179 | { | |
180 | put_dev_pagemap(page->pgmap); | |
181 | } | |
182 | EXPORT_SYMBOL(put_zone_device_page); | |
183 | ||
9476df7d DW |
184 | static void pgmap_radix_release(struct resource *res) |
185 | { | |
186 | resource_size_t key; | |
187 | ||
188 | mutex_lock(&pgmap_lock); | |
189 | for (key = res->start; key <= res->end; key += SECTION_SIZE) | |
190 | radix_tree_delete(&pgmap_radix, key >> PA_SECTION_SHIFT); | |
191 | mutex_unlock(&pgmap_lock); | |
192 | } | |
193 | ||
5c2c2587 DW |
194 | static unsigned long pfn_first(struct page_map *page_map) |
195 | { | |
196 | struct dev_pagemap *pgmap = &page_map->pgmap; | |
197 | const struct resource *res = &page_map->res; | |
198 | struct vmem_altmap *altmap = pgmap->altmap; | |
199 | unsigned long pfn; | |
200 | ||
201 | pfn = res->start >> PAGE_SHIFT; | |
202 | if (altmap) | |
203 | pfn += vmem_altmap_offset(altmap); | |
204 | return pfn; | |
205 | } | |
206 | ||
207 | static unsigned long pfn_end(struct page_map *page_map) | |
208 | { | |
209 | const struct resource *res = &page_map->res; | |
210 | ||
211 | return (res->start + resource_size(res)) >> PAGE_SHIFT; | |
212 | } | |
213 | ||
214 | #define for_each_device_pfn(pfn, map) \ | |
215 | for (pfn = pfn_first(map); pfn < pfn_end(map); pfn++) | |
216 | ||
9476df7d | 217 | static void devm_memremap_pages_release(struct device *dev, void *data) |
41e94a85 | 218 | { |
9476df7d DW |
219 | struct page_map *page_map = data; |
220 | struct resource *res = &page_map->res; | |
221 | resource_size_t align_start, align_size; | |
4b94ffdc | 222 | struct dev_pagemap *pgmap = &page_map->pgmap; |
9476df7d | 223 | |
5c2c2587 DW |
224 | if (percpu_ref_tryget_live(pgmap->ref)) { |
225 | dev_WARN(dev, "%s: page mapping is still live!\n", __func__); | |
226 | percpu_ref_put(pgmap->ref); | |
227 | } | |
228 | ||
9476df7d | 229 | pgmap_radix_release(res); |
41e94a85 CH |
230 | |
231 | /* pages are dead and unused, undo the arch mapping */ | |
9476df7d DW |
232 | align_start = res->start & ~(SECTION_SIZE - 1); |
233 | align_size = ALIGN(resource_size(res), SECTION_SIZE); | |
234 | arch_remove_memory(align_start, align_size); | |
4b94ffdc DW |
235 | dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc, |
236 | "%s: failed to free all reserved pages\n", __func__); | |
9476df7d DW |
237 | } |
238 | ||
239 | /* assumes rcu_read_lock() held at entry */ | |
240 | struct dev_pagemap *find_dev_pagemap(resource_size_t phys) | |
241 | { | |
242 | struct page_map *page_map; | |
243 | ||
244 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
245 | ||
246 | page_map = radix_tree_lookup(&pgmap_radix, phys >> PA_SECTION_SHIFT); | |
247 | return page_map ? &page_map->pgmap : NULL; | |
41e94a85 CH |
248 | } |
249 | ||
4b94ffdc DW |
250 | /** |
251 | * devm_memremap_pages - remap and provide memmap backing for the given resource | |
252 | * @dev: hosting device for @res | |
253 | * @res: "host memory" address range | |
5c2c2587 | 254 | * @ref: a live per-cpu reference count |
4b94ffdc DW |
255 | * @altmap: optional descriptor for allocating the memmap from @res |
256 | * | |
5c2c2587 DW |
257 | * Notes: |
258 | * 1/ @ref must be 'live' on entry and 'dead' before devm_memunmap_pages() time | |
259 | * (or devm release event). | |
260 | * | |
261 | * 2/ @res is expected to be a host memory range that could feasibly be | |
262 | * treated as a "System RAM" range, i.e. not a device mmio range, but | |
263 | * this is not enforced. | |
4b94ffdc DW |
264 | */ |
265 | void *devm_memremap_pages(struct device *dev, struct resource *res, | |
5c2c2587 | 266 | struct percpu_ref *ref, struct vmem_altmap *altmap) |
41e94a85 CH |
267 | { |
268 | int is_ram = region_intersects(res->start, resource_size(res), | |
269 | "System RAM"); | |
9476df7d | 270 | resource_size_t key, align_start, align_size; |
4b94ffdc | 271 | struct dev_pagemap *pgmap; |
41e94a85 | 272 | struct page_map *page_map; |
5c2c2587 | 273 | unsigned long pfn; |
41e94a85 CH |
274 | int error, nid; |
275 | ||
276 | if (is_ram == REGION_MIXED) { | |
277 | WARN_ONCE(1, "%s attempted on mixed region %pr\n", | |
278 | __func__, res); | |
279 | return ERR_PTR(-ENXIO); | |
280 | } | |
281 | ||
282 | if (is_ram == REGION_INTERSECTS) | |
283 | return __va(res->start); | |
284 | ||
4b94ffdc DW |
285 | if (altmap && !IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) { |
286 | dev_err(dev, "%s: altmap requires CONFIG_SPARSEMEM_VMEMMAP=y\n", | |
287 | __func__); | |
288 | return ERR_PTR(-ENXIO); | |
289 | } | |
290 | ||
5c2c2587 DW |
291 | if (!ref) |
292 | return ERR_PTR(-EINVAL); | |
293 | ||
538ea4aa DW |
294 | page_map = devres_alloc_node(devm_memremap_pages_release, |
295 | sizeof(*page_map), GFP_KERNEL, dev_to_node(dev)); | |
41e94a85 CH |
296 | if (!page_map) |
297 | return ERR_PTR(-ENOMEM); | |
4b94ffdc | 298 | pgmap = &page_map->pgmap; |
41e94a85 CH |
299 | |
300 | memcpy(&page_map->res, res, sizeof(*res)); | |
301 | ||
4b94ffdc DW |
302 | pgmap->dev = dev; |
303 | if (altmap) { | |
304 | memcpy(&page_map->altmap, altmap, sizeof(*altmap)); | |
305 | pgmap->altmap = &page_map->altmap; | |
306 | } | |
5c2c2587 | 307 | pgmap->ref = ref; |
4b94ffdc DW |
308 | pgmap->res = &page_map->res; |
309 | ||
9476df7d DW |
310 | mutex_lock(&pgmap_lock); |
311 | error = 0; | |
312 | for (key = res->start; key <= res->end; key += SECTION_SIZE) { | |
313 | struct dev_pagemap *dup; | |
314 | ||
315 | rcu_read_lock(); | |
316 | dup = find_dev_pagemap(key); | |
317 | rcu_read_unlock(); | |
318 | if (dup) { | |
319 | dev_err(dev, "%s: %pr collides with mapping for %s\n", | |
320 | __func__, res, dev_name(dup->dev)); | |
321 | error = -EBUSY; | |
322 | break; | |
323 | } | |
324 | error = radix_tree_insert(&pgmap_radix, key >> PA_SECTION_SHIFT, | |
325 | page_map); | |
326 | if (error) { | |
327 | dev_err(dev, "%s: failed: %d\n", __func__, error); | |
328 | break; | |
329 | } | |
330 | } | |
331 | mutex_unlock(&pgmap_lock); | |
332 | if (error) | |
333 | goto err_radix; | |
334 | ||
41e94a85 CH |
335 | nid = dev_to_node(dev); |
336 | if (nid < 0) | |
7eff93b7 | 337 | nid = numa_mem_id(); |
41e94a85 | 338 | |
9476df7d DW |
339 | align_start = res->start & ~(SECTION_SIZE - 1); |
340 | align_size = ALIGN(resource_size(res), SECTION_SIZE); | |
341 | error = arch_add_memory(nid, align_start, align_size, true); | |
342 | if (error) | |
343 | goto err_add_memory; | |
41e94a85 | 344 | |
5c2c2587 DW |
345 | for_each_device_pfn(pfn, page_map) { |
346 | struct page *page = pfn_to_page(pfn); | |
347 | ||
348 | /* ZONE_DEVICE pages must never appear on a slab lru */ | |
349 | list_force_poison(&page->lru); | |
350 | page->pgmap = pgmap; | |
351 | } | |
41e94a85 CH |
352 | devres_add(dev, page_map); |
353 | return __va(res->start); | |
9476df7d DW |
354 | |
355 | err_add_memory: | |
356 | err_radix: | |
357 | pgmap_radix_release(res); | |
358 | devres_free(page_map); | |
359 | return ERR_PTR(error); | |
41e94a85 CH |
360 | } |
361 | EXPORT_SYMBOL(devm_memremap_pages); | |
4b94ffdc DW |
362 | |
363 | unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) | |
364 | { | |
365 | /* number of pfns from base where pfn_to_page() is valid */ | |
366 | return altmap->reserve + altmap->free; | |
367 | } | |
368 | ||
369 | void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns) | |
370 | { | |
371 | altmap->alloc -= nr_pfns; | |
372 | } | |
373 | ||
374 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
375 | struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) | |
376 | { | |
377 | /* | |
378 | * 'memmap_start' is the virtual address for the first "struct | |
379 | * page" in this range of the vmemmap array. In the case of | |
380 | * CONFIG_SPARSE_VMEMMAP a page_to_pfn conversion is simple | |
381 | * pointer arithmetic, so we can perform this to_vmem_altmap() | |
382 | * conversion without concern for the initialization state of | |
383 | * the struct page fields. | |
384 | */ | |
385 | struct page *page = (struct page *) memmap_start; | |
386 | struct dev_pagemap *pgmap; | |
387 | ||
388 | /* | |
389 | * Uncoditionally retrieve a dev_pagemap associated with the | |
390 | * given physical address, this is only for use in the | |
391 | * arch_{add|remove}_memory() for setting up and tearing down | |
392 | * the memmap. | |
393 | */ | |
394 | rcu_read_lock(); | |
395 | pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page))); | |
396 | rcu_read_unlock(); | |
397 | ||
398 | return pgmap ? pgmap->altmap : NULL; | |
399 | } | |
400 | #endif /* CONFIG_SPARSEMEM_VMEMMAP */ | |
41e94a85 | 401 | #endif /* CONFIG_ZONE_DEVICE */ |