Commit | Line | Data |
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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 | { | |
ac343e88 | 32 | unsigned long pfn = PHYS_PFN(offset); |
182475b7 DW |
33 | |
34 | /* In the simple case just return the existing linear address */ | |
ac343e88 | 35 | if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn))) |
182475b7 DW |
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 | * | |
1c29f25b | 50 | * MEMREMAP_WB - matches the default mapping for System RAM on |
92281dee DW |
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 | |
1c29f25b | 59 | * map System RAM with this mapping type will fail. |
92281dee DW |
60 | */ |
61 | void *memremap(resource_size_t offset, size_t size, unsigned long flags) | |
62 | { | |
1c29f25b TK |
63 | int is_ram = region_intersects(offset, size, |
64 | IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); | |
92281dee DW |
65 | void *addr = NULL; |
66 | ||
67 | if (is_ram == REGION_MIXED) { | |
68 | WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n", | |
69 | &offset, (unsigned long) size); | |
70 | return NULL; | |
71 | } | |
72 | ||
73 | /* Try all mapping types requested until one returns non-NULL */ | |
74 | if (flags & MEMREMAP_WB) { | |
75 | flags &= ~MEMREMAP_WB; | |
76 | /* | |
77 | * MEMREMAP_WB is special in that it can be satisifed | |
78 | * from the direct map. Some archs depend on the | |
79 | * capability of memremap() to autodetect cases where | |
1c29f25b | 80 | * the requested range is potentially in System RAM. |
92281dee DW |
81 | */ |
82 | if (is_ram == REGION_INTERSECTS) | |
182475b7 DW |
83 | addr = try_ram_remap(offset, size); |
84 | if (!addr) | |
92281dee DW |
85 | addr = ioremap_cache(offset, size); |
86 | } | |
87 | ||
88 | /* | |
89 | * If we don't have a mapping yet and more request flags are | |
90 | * pending then we will be attempting to establish a new virtual | |
91 | * address mapping. Enforce that this mapping is not aliasing | |
1c29f25b | 92 | * System RAM. |
92281dee DW |
93 | */ |
94 | if (!addr && is_ram == REGION_INTERSECTS && flags) { | |
95 | WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n", | |
96 | &offset, (unsigned long) size); | |
97 | return NULL; | |
98 | } | |
99 | ||
100 | if (!addr && (flags & MEMREMAP_WT)) { | |
101 | flags &= ~MEMREMAP_WT; | |
102 | addr = ioremap_wt(offset, size); | |
103 | } | |
104 | ||
105 | return addr; | |
106 | } | |
107 | EXPORT_SYMBOL(memremap); | |
108 | ||
109 | void memunmap(void *addr) | |
110 | { | |
111 | if (is_vmalloc_addr(addr)) | |
112 | iounmap((void __iomem *) addr); | |
113 | } | |
114 | EXPORT_SYMBOL(memunmap); | |
7d3dcf26 CH |
115 | |
116 | static void devm_memremap_release(struct device *dev, void *res) | |
117 | { | |
9273a8bb | 118 | memunmap(*(void **)res); |
7d3dcf26 CH |
119 | } |
120 | ||
121 | static int devm_memremap_match(struct device *dev, void *res, void *match_data) | |
122 | { | |
123 | return *(void **)res == match_data; | |
124 | } | |
125 | ||
126 | void *devm_memremap(struct device *dev, resource_size_t offset, | |
127 | size_t size, unsigned long flags) | |
128 | { | |
129 | void **ptr, *addr; | |
130 | ||
538ea4aa DW |
131 | ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL, |
132 | dev_to_node(dev)); | |
7d3dcf26 | 133 | if (!ptr) |
b36f4761 | 134 | return ERR_PTR(-ENOMEM); |
7d3dcf26 CH |
135 | |
136 | addr = memremap(offset, size, flags); | |
137 | if (addr) { | |
138 | *ptr = addr; | |
139 | devres_add(dev, ptr); | |
93f834df | 140 | } else { |
7d3dcf26 | 141 | devres_free(ptr); |
93f834df TK |
142 | return ERR_PTR(-ENXIO); |
143 | } | |
7d3dcf26 CH |
144 | |
145 | return addr; | |
146 | } | |
147 | EXPORT_SYMBOL(devm_memremap); | |
148 | ||
149 | void devm_memunmap(struct device *dev, void *addr) | |
150 | { | |
d741314f DW |
151 | WARN_ON(devres_release(dev, devm_memremap_release, |
152 | devm_memremap_match, addr)); | |
7d3dcf26 CH |
153 | } |
154 | EXPORT_SYMBOL(devm_memunmap); | |
41e94a85 | 155 | |
db78c222 | 156 | pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags) |
34c0fd54 DW |
157 | { |
158 | return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags); | |
159 | } | |
160 | EXPORT_SYMBOL(phys_to_pfn_t); | |
161 | ||
41e94a85 | 162 | #ifdef CONFIG_ZONE_DEVICE |
9476df7d DW |
163 | static DEFINE_MUTEX(pgmap_lock); |
164 | static RADIX_TREE(pgmap_radix, GFP_KERNEL); | |
165 | #define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) | |
166 | #define SECTION_SIZE (1UL << PA_SECTION_SHIFT) | |
167 | ||
41e94a85 CH |
168 | struct page_map { |
169 | struct resource res; | |
9476df7d DW |
170 | struct percpu_ref *ref; |
171 | struct dev_pagemap pgmap; | |
4b94ffdc | 172 | struct vmem_altmap altmap; |
41e94a85 CH |
173 | }; |
174 | ||
3565fce3 DW |
175 | void get_zone_device_page(struct page *page) |
176 | { | |
177 | percpu_ref_get(page->pgmap->ref); | |
178 | } | |
179 | EXPORT_SYMBOL(get_zone_device_page); | |
180 | ||
181 | void put_zone_device_page(struct page *page) | |
182 | { | |
183 | put_dev_pagemap(page->pgmap); | |
184 | } | |
185 | EXPORT_SYMBOL(put_zone_device_page); | |
186 | ||
9476df7d DW |
187 | static void pgmap_radix_release(struct resource *res) |
188 | { | |
eb7d78c9 DW |
189 | resource_size_t key, align_start, align_size, align_end; |
190 | ||
191 | align_start = res->start & ~(SECTION_SIZE - 1); | |
192 | align_size = ALIGN(resource_size(res), SECTION_SIZE); | |
193 | align_end = align_start + align_size - 1; | |
9476df7d DW |
194 | |
195 | mutex_lock(&pgmap_lock); | |
196 | for (key = res->start; key <= res->end; key += SECTION_SIZE) | |
197 | radix_tree_delete(&pgmap_radix, key >> PA_SECTION_SHIFT); | |
198 | mutex_unlock(&pgmap_lock); | |
199 | } | |
200 | ||
5c2c2587 DW |
201 | static unsigned long pfn_first(struct page_map *page_map) |
202 | { | |
203 | struct dev_pagemap *pgmap = &page_map->pgmap; | |
204 | const struct resource *res = &page_map->res; | |
205 | struct vmem_altmap *altmap = pgmap->altmap; | |
206 | unsigned long pfn; | |
207 | ||
208 | pfn = res->start >> PAGE_SHIFT; | |
209 | if (altmap) | |
210 | pfn += vmem_altmap_offset(altmap); | |
211 | return pfn; | |
212 | } | |
213 | ||
214 | static unsigned long pfn_end(struct page_map *page_map) | |
215 | { | |
216 | const struct resource *res = &page_map->res; | |
217 | ||
218 | return (res->start + resource_size(res)) >> PAGE_SHIFT; | |
219 | } | |
220 | ||
221 | #define for_each_device_pfn(pfn, map) \ | |
222 | for (pfn = pfn_first(map); pfn < pfn_end(map); pfn++) | |
223 | ||
9476df7d | 224 | static void devm_memremap_pages_release(struct device *dev, void *data) |
41e94a85 | 225 | { |
9476df7d DW |
226 | struct page_map *page_map = data; |
227 | struct resource *res = &page_map->res; | |
228 | resource_size_t align_start, align_size; | |
4b94ffdc | 229 | struct dev_pagemap *pgmap = &page_map->pgmap; |
9476df7d | 230 | |
5c2c2587 DW |
231 | if (percpu_ref_tryget_live(pgmap->ref)) { |
232 | dev_WARN(dev, "%s: page mapping is still live!\n", __func__); | |
233 | percpu_ref_put(pgmap->ref); | |
234 | } | |
235 | ||
41e94a85 | 236 | /* pages are dead and unused, undo the arch mapping */ |
9476df7d DW |
237 | align_start = res->start & ~(SECTION_SIZE - 1); |
238 | align_size = ALIGN(resource_size(res), SECTION_SIZE); | |
239 | arch_remove_memory(align_start, align_size); | |
eb7d78c9 | 240 | pgmap_radix_release(res); |
4b94ffdc DW |
241 | dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc, |
242 | "%s: failed to free all reserved pages\n", __func__); | |
9476df7d DW |
243 | } |
244 | ||
245 | /* assumes rcu_read_lock() held at entry */ | |
246 | struct dev_pagemap *find_dev_pagemap(resource_size_t phys) | |
247 | { | |
248 | struct page_map *page_map; | |
249 | ||
250 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
251 | ||
252 | page_map = radix_tree_lookup(&pgmap_radix, phys >> PA_SECTION_SHIFT); | |
253 | return page_map ? &page_map->pgmap : NULL; | |
41e94a85 CH |
254 | } |
255 | ||
4b94ffdc DW |
256 | /** |
257 | * devm_memremap_pages - remap and provide memmap backing for the given resource | |
258 | * @dev: hosting device for @res | |
259 | * @res: "host memory" address range | |
5c2c2587 | 260 | * @ref: a live per-cpu reference count |
4b94ffdc DW |
261 | * @altmap: optional descriptor for allocating the memmap from @res |
262 | * | |
5c2c2587 DW |
263 | * Notes: |
264 | * 1/ @ref must be 'live' on entry and 'dead' before devm_memunmap_pages() time | |
265 | * (or devm release event). | |
266 | * | |
267 | * 2/ @res is expected to be a host memory range that could feasibly be | |
268 | * treated as a "System RAM" range, i.e. not a device mmio range, but | |
269 | * this is not enforced. | |
4b94ffdc DW |
270 | */ |
271 | void *devm_memremap_pages(struct device *dev, struct resource *res, | |
5c2c2587 | 272 | struct percpu_ref *ref, struct vmem_altmap *altmap) |
41e94a85 | 273 | { |
eb7d78c9 | 274 | resource_size_t key, align_start, align_size, align_end; |
4b94ffdc | 275 | struct dev_pagemap *pgmap; |
41e94a85 | 276 | struct page_map *page_map; |
5f29a77c | 277 | int error, nid, is_ram; |
5c2c2587 | 278 | unsigned long pfn; |
5f29a77c DW |
279 | |
280 | align_start = res->start & ~(SECTION_SIZE - 1); | |
281 | align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) | |
282 | - align_start; | |
d37a14bb LT |
283 | is_ram = region_intersects(align_start, align_size, |
284 | IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); | |
41e94a85 CH |
285 | |
286 | if (is_ram == REGION_MIXED) { | |
287 | WARN_ONCE(1, "%s attempted on mixed region %pr\n", | |
288 | __func__, res); | |
289 | return ERR_PTR(-ENXIO); | |
290 | } | |
291 | ||
292 | if (is_ram == REGION_INTERSECTS) | |
293 | return __va(res->start); | |
294 | ||
4b94ffdc DW |
295 | if (altmap && !IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) { |
296 | dev_err(dev, "%s: altmap requires CONFIG_SPARSEMEM_VMEMMAP=y\n", | |
297 | __func__); | |
298 | return ERR_PTR(-ENXIO); | |
299 | } | |
300 | ||
5c2c2587 DW |
301 | if (!ref) |
302 | return ERR_PTR(-EINVAL); | |
303 | ||
538ea4aa DW |
304 | page_map = devres_alloc_node(devm_memremap_pages_release, |
305 | sizeof(*page_map), GFP_KERNEL, dev_to_node(dev)); | |
41e94a85 CH |
306 | if (!page_map) |
307 | return ERR_PTR(-ENOMEM); | |
4b94ffdc | 308 | pgmap = &page_map->pgmap; |
41e94a85 CH |
309 | |
310 | memcpy(&page_map->res, res, sizeof(*res)); | |
311 | ||
4b94ffdc DW |
312 | pgmap->dev = dev; |
313 | if (altmap) { | |
314 | memcpy(&page_map->altmap, altmap, sizeof(*altmap)); | |
315 | pgmap->altmap = &page_map->altmap; | |
316 | } | |
5c2c2587 | 317 | pgmap->ref = ref; |
4b94ffdc DW |
318 | pgmap->res = &page_map->res; |
319 | ||
9476df7d DW |
320 | mutex_lock(&pgmap_lock); |
321 | error = 0; | |
eb7d78c9 DW |
322 | align_end = align_start + align_size - 1; |
323 | for (key = align_start; key <= align_end; key += SECTION_SIZE) { | |
9476df7d DW |
324 | struct dev_pagemap *dup; |
325 | ||
326 | rcu_read_lock(); | |
327 | dup = find_dev_pagemap(key); | |
328 | rcu_read_unlock(); | |
329 | if (dup) { | |
330 | dev_err(dev, "%s: %pr collides with mapping for %s\n", | |
331 | __func__, res, dev_name(dup->dev)); | |
332 | error = -EBUSY; | |
333 | break; | |
334 | } | |
335 | error = radix_tree_insert(&pgmap_radix, key >> PA_SECTION_SHIFT, | |
336 | page_map); | |
337 | if (error) { | |
338 | dev_err(dev, "%s: failed: %d\n", __func__, error); | |
339 | break; | |
340 | } | |
341 | } | |
342 | mutex_unlock(&pgmap_lock); | |
343 | if (error) | |
344 | goto err_radix; | |
345 | ||
41e94a85 CH |
346 | nid = dev_to_node(dev); |
347 | if (nid < 0) | |
7eff93b7 | 348 | nid = numa_mem_id(); |
41e94a85 | 349 | |
9476df7d DW |
350 | error = arch_add_memory(nid, align_start, align_size, true); |
351 | if (error) | |
352 | goto err_add_memory; | |
41e94a85 | 353 | |
5c2c2587 DW |
354 | for_each_device_pfn(pfn, page_map) { |
355 | struct page *page = pfn_to_page(pfn); | |
356 | ||
d77a117e DW |
357 | /* |
358 | * ZONE_DEVICE pages union ->lru with a ->pgmap back | |
359 | * pointer. It is a bug if a ZONE_DEVICE page is ever | |
360 | * freed or placed on a driver-private list. Seed the | |
361 | * storage with LIST_POISON* values. | |
362 | */ | |
363 | list_del(&page->lru); | |
5c2c2587 DW |
364 | page->pgmap = pgmap; |
365 | } | |
41e94a85 CH |
366 | devres_add(dev, page_map); |
367 | return __va(res->start); | |
9476df7d DW |
368 | |
369 | err_add_memory: | |
370 | err_radix: | |
371 | pgmap_radix_release(res); | |
372 | devres_free(page_map); | |
373 | return ERR_PTR(error); | |
41e94a85 CH |
374 | } |
375 | EXPORT_SYMBOL(devm_memremap_pages); | |
4b94ffdc DW |
376 | |
377 | unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) | |
378 | { | |
379 | /* number of pfns from base where pfn_to_page() is valid */ | |
380 | return altmap->reserve + altmap->free; | |
381 | } | |
382 | ||
383 | void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns) | |
384 | { | |
385 | altmap->alloc -= nr_pfns; | |
386 | } | |
387 | ||
388 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
389 | struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) | |
390 | { | |
391 | /* | |
392 | * 'memmap_start' is the virtual address for the first "struct | |
393 | * page" in this range of the vmemmap array. In the case of | |
07061aab | 394 | * CONFIG_SPARSEMEM_VMEMMAP a page_to_pfn conversion is simple |
4b94ffdc DW |
395 | * pointer arithmetic, so we can perform this to_vmem_altmap() |
396 | * conversion without concern for the initialization state of | |
397 | * the struct page fields. | |
398 | */ | |
399 | struct page *page = (struct page *) memmap_start; | |
400 | struct dev_pagemap *pgmap; | |
401 | ||
402 | /* | |
07061aab | 403 | * Unconditionally retrieve a dev_pagemap associated with the |
4b94ffdc DW |
404 | * given physical address, this is only for use in the |
405 | * arch_{add|remove}_memory() for setting up and tearing down | |
406 | * the memmap. | |
407 | */ | |
408 | rcu_read_lock(); | |
409 | pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page))); | |
410 | rcu_read_unlock(); | |
411 | ||
412 | return pgmap ? pgmap->altmap : NULL; | |
413 | } | |
414 | #endif /* CONFIG_SPARSEMEM_VMEMMAP */ | |
41e94a85 | 415 | #endif /* CONFIG_ZONE_DEVICE */ |