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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 | |
c907e0eb | 44 | * @flags: any of MEMREMAP_WB, MEMREMAP_WT and MEMREMAP_WC |
92281dee DW |
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 | |
c907e0eb BS |
48 | * annotation is not applicable. In the case of multiple flags, the different |
49 | * mapping types will be attempted in the order listed below until one of | |
50 | * them succeeds. | |
92281dee | 51 | * |
1c29f25b | 52 | * MEMREMAP_WB - matches the default mapping for System RAM on |
92281dee DW |
53 | * the architecture. This is usually a read-allocate write-back cache. |
54 | * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM | |
55 | * memremap() will bypass establishing a new mapping and instead return | |
56 | * a pointer into the direct map. | |
57 | * | |
58 | * MEMREMAP_WT - establish a mapping whereby writes either bypass the | |
59 | * cache or are written through to memory and never exist in a | |
60 | * cache-dirty state with respect to program visibility. Attempts to | |
1c29f25b | 61 | * map System RAM with this mapping type will fail. |
c907e0eb BS |
62 | * |
63 | * MEMREMAP_WC - establish a writecombine mapping, whereby writes may | |
64 | * be coalesced together (e.g. in the CPU's write buffers), but is otherwise | |
65 | * uncached. Attempts to map System RAM with this mapping type will fail. | |
92281dee DW |
66 | */ |
67 | void *memremap(resource_size_t offset, size_t size, unsigned long flags) | |
68 | { | |
1c29f25b TK |
69 | int is_ram = region_intersects(offset, size, |
70 | IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); | |
92281dee DW |
71 | void *addr = NULL; |
72 | ||
cf61e2a1 BS |
73 | if (!flags) |
74 | return NULL; | |
75 | ||
92281dee DW |
76 | if (is_ram == REGION_MIXED) { |
77 | WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n", | |
78 | &offset, (unsigned long) size); | |
79 | return NULL; | |
80 | } | |
81 | ||
82 | /* Try all mapping types requested until one returns non-NULL */ | |
83 | if (flags & MEMREMAP_WB) { | |
92281dee DW |
84 | /* |
85 | * MEMREMAP_WB is special in that it can be satisifed | |
86 | * from the direct map. Some archs depend on the | |
87 | * capability of memremap() to autodetect cases where | |
1c29f25b | 88 | * the requested range is potentially in System RAM. |
92281dee DW |
89 | */ |
90 | if (is_ram == REGION_INTERSECTS) | |
182475b7 DW |
91 | addr = try_ram_remap(offset, size); |
92 | if (!addr) | |
92281dee DW |
93 | addr = ioremap_cache(offset, size); |
94 | } | |
95 | ||
96 | /* | |
cf61e2a1 BS |
97 | * If we don't have a mapping yet and other request flags are |
98 | * present then we will be attempting to establish a new virtual | |
92281dee | 99 | * address mapping. Enforce that this mapping is not aliasing |
1c29f25b | 100 | * System RAM. |
92281dee | 101 | */ |
cf61e2a1 | 102 | if (!addr && is_ram == REGION_INTERSECTS && flags != MEMREMAP_WB) { |
92281dee DW |
103 | WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n", |
104 | &offset, (unsigned long) size); | |
105 | return NULL; | |
106 | } | |
107 | ||
cf61e2a1 | 108 | if (!addr && (flags & MEMREMAP_WT)) |
92281dee | 109 | addr = ioremap_wt(offset, size); |
c907e0eb BS |
110 | |
111 | if (!addr && (flags & MEMREMAP_WC)) | |
112 | addr = ioremap_wc(offset, size); | |
92281dee DW |
113 | |
114 | return addr; | |
115 | } | |
116 | EXPORT_SYMBOL(memremap); | |
117 | ||
118 | void memunmap(void *addr) | |
119 | { | |
120 | if (is_vmalloc_addr(addr)) | |
121 | iounmap((void __iomem *) addr); | |
122 | } | |
123 | EXPORT_SYMBOL(memunmap); | |
7d3dcf26 CH |
124 | |
125 | static void devm_memremap_release(struct device *dev, void *res) | |
126 | { | |
9273a8bb | 127 | memunmap(*(void **)res); |
7d3dcf26 CH |
128 | } |
129 | ||
130 | static int devm_memremap_match(struct device *dev, void *res, void *match_data) | |
131 | { | |
132 | return *(void **)res == match_data; | |
133 | } | |
134 | ||
135 | void *devm_memremap(struct device *dev, resource_size_t offset, | |
136 | size_t size, unsigned long flags) | |
137 | { | |
138 | void **ptr, *addr; | |
139 | ||
538ea4aa DW |
140 | ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL, |
141 | dev_to_node(dev)); | |
7d3dcf26 | 142 | if (!ptr) |
b36f4761 | 143 | return ERR_PTR(-ENOMEM); |
7d3dcf26 CH |
144 | |
145 | addr = memremap(offset, size, flags); | |
146 | if (addr) { | |
147 | *ptr = addr; | |
148 | devres_add(dev, ptr); | |
93f834df | 149 | } else { |
7d3dcf26 | 150 | devres_free(ptr); |
93f834df TK |
151 | return ERR_PTR(-ENXIO); |
152 | } | |
7d3dcf26 CH |
153 | |
154 | return addr; | |
155 | } | |
156 | EXPORT_SYMBOL(devm_memremap); | |
157 | ||
158 | void devm_memunmap(struct device *dev, void *addr) | |
159 | { | |
d741314f DW |
160 | WARN_ON(devres_release(dev, devm_memremap_release, |
161 | devm_memremap_match, addr)); | |
7d3dcf26 CH |
162 | } |
163 | EXPORT_SYMBOL(devm_memunmap); | |
41e94a85 | 164 | |
db78c222 | 165 | pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags) |
34c0fd54 DW |
166 | { |
167 | return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags); | |
168 | } | |
169 | EXPORT_SYMBOL(phys_to_pfn_t); | |
170 | ||
41e94a85 | 171 | #ifdef CONFIG_ZONE_DEVICE |
9476df7d DW |
172 | static DEFINE_MUTEX(pgmap_lock); |
173 | static RADIX_TREE(pgmap_radix, GFP_KERNEL); | |
174 | #define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) | |
175 | #define SECTION_SIZE (1UL << PA_SECTION_SHIFT) | |
176 | ||
41e94a85 CH |
177 | struct page_map { |
178 | struct resource res; | |
9476df7d DW |
179 | struct percpu_ref *ref; |
180 | struct dev_pagemap pgmap; | |
4b94ffdc | 181 | struct vmem_altmap altmap; |
41e94a85 CH |
182 | }; |
183 | ||
3565fce3 DW |
184 | void get_zone_device_page(struct page *page) |
185 | { | |
186 | percpu_ref_get(page->pgmap->ref); | |
187 | } | |
188 | EXPORT_SYMBOL(get_zone_device_page); | |
189 | ||
190 | void put_zone_device_page(struct page *page) | |
191 | { | |
192 | put_dev_pagemap(page->pgmap); | |
193 | } | |
194 | EXPORT_SYMBOL(put_zone_device_page); | |
195 | ||
9476df7d DW |
196 | static void pgmap_radix_release(struct resource *res) |
197 | { | |
eb7d78c9 DW |
198 | resource_size_t key, align_start, align_size, align_end; |
199 | ||
200 | align_start = res->start & ~(SECTION_SIZE - 1); | |
201 | align_size = ALIGN(resource_size(res), SECTION_SIZE); | |
202 | align_end = align_start + align_size - 1; | |
9476df7d DW |
203 | |
204 | mutex_lock(&pgmap_lock); | |
205 | for (key = res->start; key <= res->end; key += SECTION_SIZE) | |
206 | radix_tree_delete(&pgmap_radix, key >> PA_SECTION_SHIFT); | |
207 | mutex_unlock(&pgmap_lock); | |
208 | } | |
209 | ||
5c2c2587 DW |
210 | static unsigned long pfn_first(struct page_map *page_map) |
211 | { | |
212 | struct dev_pagemap *pgmap = &page_map->pgmap; | |
213 | const struct resource *res = &page_map->res; | |
214 | struct vmem_altmap *altmap = pgmap->altmap; | |
215 | unsigned long pfn; | |
216 | ||
217 | pfn = res->start >> PAGE_SHIFT; | |
218 | if (altmap) | |
219 | pfn += vmem_altmap_offset(altmap); | |
220 | return pfn; | |
221 | } | |
222 | ||
223 | static unsigned long pfn_end(struct page_map *page_map) | |
224 | { | |
225 | const struct resource *res = &page_map->res; | |
226 | ||
227 | return (res->start + resource_size(res)) >> PAGE_SHIFT; | |
228 | } | |
229 | ||
230 | #define for_each_device_pfn(pfn, map) \ | |
231 | for (pfn = pfn_first(map); pfn < pfn_end(map); pfn++) | |
232 | ||
9476df7d | 233 | static void devm_memremap_pages_release(struct device *dev, void *data) |
41e94a85 | 234 | { |
9476df7d DW |
235 | struct page_map *page_map = data; |
236 | struct resource *res = &page_map->res; | |
237 | resource_size_t align_start, align_size; | |
4b94ffdc | 238 | struct dev_pagemap *pgmap = &page_map->pgmap; |
9476df7d | 239 | |
5c2c2587 DW |
240 | if (percpu_ref_tryget_live(pgmap->ref)) { |
241 | dev_WARN(dev, "%s: page mapping is still live!\n", __func__); | |
242 | percpu_ref_put(pgmap->ref); | |
243 | } | |
244 | ||
41e94a85 | 245 | /* pages are dead and unused, undo the arch mapping */ |
9476df7d DW |
246 | align_start = res->start & ~(SECTION_SIZE - 1); |
247 | align_size = ALIGN(resource_size(res), SECTION_SIZE); | |
248 | arch_remove_memory(align_start, align_size); | |
eb7d78c9 | 249 | pgmap_radix_release(res); |
4b94ffdc DW |
250 | dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc, |
251 | "%s: failed to free all reserved pages\n", __func__); | |
9476df7d DW |
252 | } |
253 | ||
254 | /* assumes rcu_read_lock() held at entry */ | |
255 | struct dev_pagemap *find_dev_pagemap(resource_size_t phys) | |
256 | { | |
257 | struct page_map *page_map; | |
258 | ||
259 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
260 | ||
261 | page_map = radix_tree_lookup(&pgmap_radix, phys >> PA_SECTION_SHIFT); | |
262 | return page_map ? &page_map->pgmap : NULL; | |
41e94a85 CH |
263 | } |
264 | ||
4b94ffdc DW |
265 | /** |
266 | * devm_memremap_pages - remap and provide memmap backing for the given resource | |
267 | * @dev: hosting device for @res | |
268 | * @res: "host memory" address range | |
5c2c2587 | 269 | * @ref: a live per-cpu reference count |
4b94ffdc DW |
270 | * @altmap: optional descriptor for allocating the memmap from @res |
271 | * | |
5c2c2587 DW |
272 | * Notes: |
273 | * 1/ @ref must be 'live' on entry and 'dead' before devm_memunmap_pages() time | |
274 | * (or devm release event). | |
275 | * | |
276 | * 2/ @res is expected to be a host memory range that could feasibly be | |
277 | * treated as a "System RAM" range, i.e. not a device mmio range, but | |
278 | * this is not enforced. | |
4b94ffdc DW |
279 | */ |
280 | void *devm_memremap_pages(struct device *dev, struct resource *res, | |
5c2c2587 | 281 | struct percpu_ref *ref, struct vmem_altmap *altmap) |
41e94a85 | 282 | { |
eb7d78c9 | 283 | resource_size_t key, align_start, align_size, align_end; |
4b94ffdc | 284 | struct dev_pagemap *pgmap; |
41e94a85 | 285 | struct page_map *page_map; |
5f29a77c | 286 | int error, nid, is_ram; |
5c2c2587 | 287 | unsigned long pfn; |
5f29a77c DW |
288 | |
289 | align_start = res->start & ~(SECTION_SIZE - 1); | |
290 | align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) | |
291 | - align_start; | |
d37a14bb LT |
292 | is_ram = region_intersects(align_start, align_size, |
293 | IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); | |
41e94a85 CH |
294 | |
295 | if (is_ram == REGION_MIXED) { | |
296 | WARN_ONCE(1, "%s attempted on mixed region %pr\n", | |
297 | __func__, res); | |
298 | return ERR_PTR(-ENXIO); | |
299 | } | |
300 | ||
301 | if (is_ram == REGION_INTERSECTS) | |
302 | return __va(res->start); | |
303 | ||
4b94ffdc DW |
304 | if (altmap && !IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) { |
305 | dev_err(dev, "%s: altmap requires CONFIG_SPARSEMEM_VMEMMAP=y\n", | |
306 | __func__); | |
307 | return ERR_PTR(-ENXIO); | |
308 | } | |
309 | ||
5c2c2587 DW |
310 | if (!ref) |
311 | return ERR_PTR(-EINVAL); | |
312 | ||
538ea4aa DW |
313 | page_map = devres_alloc_node(devm_memremap_pages_release, |
314 | sizeof(*page_map), GFP_KERNEL, dev_to_node(dev)); | |
41e94a85 CH |
315 | if (!page_map) |
316 | return ERR_PTR(-ENOMEM); | |
4b94ffdc | 317 | pgmap = &page_map->pgmap; |
41e94a85 CH |
318 | |
319 | memcpy(&page_map->res, res, sizeof(*res)); | |
320 | ||
4b94ffdc DW |
321 | pgmap->dev = dev; |
322 | if (altmap) { | |
323 | memcpy(&page_map->altmap, altmap, sizeof(*altmap)); | |
324 | pgmap->altmap = &page_map->altmap; | |
325 | } | |
5c2c2587 | 326 | pgmap->ref = ref; |
4b94ffdc DW |
327 | pgmap->res = &page_map->res; |
328 | ||
9476df7d DW |
329 | mutex_lock(&pgmap_lock); |
330 | error = 0; | |
eb7d78c9 DW |
331 | align_end = align_start + align_size - 1; |
332 | for (key = align_start; key <= align_end; key += SECTION_SIZE) { | |
9476df7d DW |
333 | struct dev_pagemap *dup; |
334 | ||
335 | rcu_read_lock(); | |
336 | dup = find_dev_pagemap(key); | |
337 | rcu_read_unlock(); | |
338 | if (dup) { | |
339 | dev_err(dev, "%s: %pr collides with mapping for %s\n", | |
340 | __func__, res, dev_name(dup->dev)); | |
341 | error = -EBUSY; | |
342 | break; | |
343 | } | |
344 | error = radix_tree_insert(&pgmap_radix, key >> PA_SECTION_SHIFT, | |
345 | page_map); | |
346 | if (error) { | |
347 | dev_err(dev, "%s: failed: %d\n", __func__, error); | |
348 | break; | |
349 | } | |
350 | } | |
351 | mutex_unlock(&pgmap_lock); | |
352 | if (error) | |
353 | goto err_radix; | |
354 | ||
41e94a85 CH |
355 | nid = dev_to_node(dev); |
356 | if (nid < 0) | |
7eff93b7 | 357 | nid = numa_mem_id(); |
41e94a85 | 358 | |
9476df7d DW |
359 | error = arch_add_memory(nid, align_start, align_size, true); |
360 | if (error) | |
361 | goto err_add_memory; | |
41e94a85 | 362 | |
5c2c2587 DW |
363 | for_each_device_pfn(pfn, page_map) { |
364 | struct page *page = pfn_to_page(pfn); | |
365 | ||
d77a117e DW |
366 | /* |
367 | * ZONE_DEVICE pages union ->lru with a ->pgmap back | |
368 | * pointer. It is a bug if a ZONE_DEVICE page is ever | |
369 | * freed or placed on a driver-private list. Seed the | |
370 | * storage with LIST_POISON* values. | |
371 | */ | |
372 | list_del(&page->lru); | |
5c2c2587 DW |
373 | page->pgmap = pgmap; |
374 | } | |
41e94a85 CH |
375 | devres_add(dev, page_map); |
376 | return __va(res->start); | |
9476df7d DW |
377 | |
378 | err_add_memory: | |
379 | err_radix: | |
380 | pgmap_radix_release(res); | |
381 | devres_free(page_map); | |
382 | return ERR_PTR(error); | |
41e94a85 CH |
383 | } |
384 | EXPORT_SYMBOL(devm_memremap_pages); | |
4b94ffdc DW |
385 | |
386 | unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) | |
387 | { | |
388 | /* number of pfns from base where pfn_to_page() is valid */ | |
389 | return altmap->reserve + altmap->free; | |
390 | } | |
391 | ||
392 | void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns) | |
393 | { | |
394 | altmap->alloc -= nr_pfns; | |
395 | } | |
396 | ||
397 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
398 | struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) | |
399 | { | |
400 | /* | |
401 | * 'memmap_start' is the virtual address for the first "struct | |
402 | * page" in this range of the vmemmap array. In the case of | |
07061aab | 403 | * CONFIG_SPARSEMEM_VMEMMAP a page_to_pfn conversion is simple |
4b94ffdc DW |
404 | * pointer arithmetic, so we can perform this to_vmem_altmap() |
405 | * conversion without concern for the initialization state of | |
406 | * the struct page fields. | |
407 | */ | |
408 | struct page *page = (struct page *) memmap_start; | |
409 | struct dev_pagemap *pgmap; | |
410 | ||
411 | /* | |
07061aab | 412 | * Unconditionally retrieve a dev_pagemap associated with the |
4b94ffdc DW |
413 | * given physical address, this is only for use in the |
414 | * arch_{add|remove}_memory() for setting up and tearing down | |
415 | * the memmap. | |
416 | */ | |
417 | rcu_read_lock(); | |
418 | pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page))); | |
419 | rcu_read_unlock(); | |
420 | ||
421 | return pgmap ? pgmap->altmap : NULL; | |
422 | } | |
423 | #endif /* CONFIG_SPARSEMEM_VMEMMAP */ | |
41e94a85 | 424 | #endif /* CONFIG_ZONE_DEVICE */ |