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5981690d DW |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* Copyright(c) 2015 Intel Corporation. All rights reserved. */ | |
7d3dcf26 | 3 | #include <linux/device.h> |
92281dee | 4 | #include <linux/io.h> |
0207df4f | 5 | #include <linux/kasan.h> |
41e94a85 | 6 | #include <linux/memory_hotplug.h> |
bcfa4b72 MW |
7 | #include <linux/mm.h> |
8 | #include <linux/pfn_t.h> | |
5042db43 JG |
9 | #include <linux/swap.h> |
10 | #include <linux/swapops.h> | |
bcfa4b72 | 11 | #include <linux/types.h> |
e7638488 | 12 | #include <linux/wait_bit.h> |
bcfa4b72 | 13 | #include <linux/xarray.h> |
92281dee | 14 | |
bcfa4b72 | 15 | static DEFINE_XARRAY(pgmap_array); |
9476df7d DW |
16 | #define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) |
17 | #define SECTION_SIZE (1UL << PA_SECTION_SHIFT) | |
18 | ||
f6a55e1a CH |
19 | #ifdef CONFIG_DEV_PAGEMAP_OPS |
20 | DEFINE_STATIC_KEY_FALSE(devmap_managed_key); | |
21 | EXPORT_SYMBOL(devmap_managed_key); | |
22 | static atomic_t devmap_managed_enable; | |
23 | ||
6f42193f | 24 | static void devmap_managed_enable_put(void) |
f6a55e1a CH |
25 | { |
26 | if (atomic_dec_and_test(&devmap_managed_enable)) | |
27 | static_branch_disable(&devmap_managed_key); | |
28 | } | |
29 | ||
6f42193f | 30 | static int devmap_managed_enable_get(struct dev_pagemap *pgmap) |
f6a55e1a | 31 | { |
24917f6b | 32 | if (!pgmap->ops || !pgmap->ops->page_free) { |
f6a55e1a CH |
33 | WARN(1, "Missing page_free method\n"); |
34 | return -EINVAL; | |
35 | } | |
36 | ||
37 | if (atomic_inc_return(&devmap_managed_enable) == 1) | |
38 | static_branch_enable(&devmap_managed_key); | |
6f42193f | 39 | return 0; |
f6a55e1a CH |
40 | } |
41 | #else | |
6f42193f | 42 | static int devmap_managed_enable_get(struct dev_pagemap *pgmap) |
f6a55e1a CH |
43 | { |
44 | return -EINVAL; | |
45 | } | |
6f42193f CH |
46 | static void devmap_managed_enable_put(void) |
47 | { | |
48 | } | |
f6a55e1a CH |
49 | #endif /* CONFIG_DEV_PAGEMAP_OPS */ |
50 | ||
bcfa4b72 | 51 | static void pgmap_array_delete(struct resource *res) |
ab1b597e | 52 | { |
bcfa4b72 MW |
53 | xa_store_range(&pgmap_array, PHYS_PFN(res->start), PHYS_PFN(res->end), |
54 | NULL, GFP_KERNEL); | |
ab1b597e | 55 | synchronize_rcu(); |
9476df7d DW |
56 | } |
57 | ||
e7744aa2 | 58 | static unsigned long pfn_first(struct dev_pagemap *pgmap) |
5c2c2587 | 59 | { |
7cc7867f | 60 | return PHYS_PFN(pgmap->res.start) + |
514caf23 | 61 | vmem_altmap_offset(pgmap_altmap(pgmap)); |
5c2c2587 DW |
62 | } |
63 | ||
e7744aa2 | 64 | static unsigned long pfn_end(struct dev_pagemap *pgmap) |
5c2c2587 | 65 | { |
e7744aa2 | 66 | const struct resource *res = &pgmap->res; |
5c2c2587 DW |
67 | |
68 | return (res->start + resource_size(res)) >> PAGE_SHIFT; | |
69 | } | |
70 | ||
949b9325 DW |
71 | static unsigned long pfn_next(unsigned long pfn) |
72 | { | |
73 | if (pfn % 1024 == 0) | |
74 | cond_resched(); | |
75 | return pfn + 1; | |
76 | } | |
77 | ||
5c2c2587 | 78 | #define for_each_device_pfn(pfn, map) \ |
949b9325 | 79 | for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn)) |
5c2c2587 | 80 | |
24917f6b CH |
81 | static void dev_pagemap_kill(struct dev_pagemap *pgmap) |
82 | { | |
83 | if (pgmap->ops && pgmap->ops->kill) | |
84 | pgmap->ops->kill(pgmap); | |
85 | else | |
86 | percpu_ref_kill(pgmap->ref); | |
87 | } | |
88 | ||
89 | static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) | |
90 | { | |
91 | if (pgmap->ops && pgmap->ops->cleanup) { | |
92 | pgmap->ops->cleanup(pgmap); | |
93 | } else { | |
94 | wait_for_completion(&pgmap->done); | |
95 | percpu_ref_exit(pgmap->ref); | |
96 | } | |
06282373 DW |
97 | /* |
98 | * Undo the pgmap ref assignment for the internal case as the | |
99 | * caller may re-enable the same pgmap. | |
100 | */ | |
101 | if (pgmap->ref == &pgmap->internal_ref) | |
102 | pgmap->ref = NULL; | |
24917f6b CH |
103 | } |
104 | ||
6869b7b2 | 105 | void memunmap_pages(struct dev_pagemap *pgmap) |
41e94a85 | 106 | { |
e7744aa2 | 107 | struct resource *res = &pgmap->res; |
71389703 | 108 | unsigned long pfn; |
2c2a5af6 | 109 | int nid; |
71389703 | 110 | |
24917f6b | 111 | dev_pagemap_kill(pgmap); |
e7744aa2 | 112 | for_each_device_pfn(pfn, pgmap) |
71389703 | 113 | put_page(pfn_to_page(pfn)); |
24917f6b | 114 | dev_pagemap_cleanup(pgmap); |
9476df7d | 115 | |
41e94a85 | 116 | /* pages are dead and unused, undo the arch mapping */ |
7cc7867f | 117 | nid = page_to_nid(pfn_to_page(PHYS_PFN(res->start))); |
2c2a5af6 | 118 | |
f931ab47 | 119 | mem_hotplug_begin(); |
69324b8f | 120 | if (pgmap->type == MEMORY_DEVICE_PRIVATE) { |
7cc7867f | 121 | pfn = PHYS_PFN(res->start); |
69324b8f | 122 | __remove_pages(page_zone(pfn_to_page(pfn)), pfn, |
7cc7867f | 123 | PHYS_PFN(resource_size(res)), NULL); |
69324b8f | 124 | } else { |
7cc7867f | 125 | arch_remove_memory(nid, res->start, resource_size(res), |
514caf23 | 126 | pgmap_altmap(pgmap)); |
7cc7867f | 127 | kasan_remove_zero_shadow(__va(res->start), resource_size(res)); |
69324b8f | 128 | } |
f931ab47 | 129 | mem_hotplug_done(); |
b5d24fda | 130 | |
7cc7867f | 131 | untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res)); |
bcfa4b72 | 132 | pgmap_array_delete(res); |
fdc029b1 | 133 | WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n"); |
6f42193f | 134 | devmap_managed_enable_put(); |
9476df7d | 135 | } |
6869b7b2 CH |
136 | EXPORT_SYMBOL_GPL(memunmap_pages); |
137 | ||
138 | static void devm_memremap_pages_release(void *data) | |
139 | { | |
140 | memunmap_pages(data); | |
141 | } | |
9476df7d | 142 | |
24917f6b CH |
143 | static void dev_pagemap_percpu_release(struct percpu_ref *ref) |
144 | { | |
145 | struct dev_pagemap *pgmap = | |
146 | container_of(ref, struct dev_pagemap, internal_ref); | |
147 | ||
148 | complete(&pgmap->done); | |
149 | } | |
150 | ||
6869b7b2 CH |
151 | /* |
152 | * Not device managed version of dev_memremap_pages, undone by | |
153 | * memunmap_pages(). Please use dev_memremap_pages if you have a struct | |
154 | * device available. | |
4b94ffdc | 155 | */ |
6869b7b2 | 156 | void *memremap_pages(struct dev_pagemap *pgmap, int nid) |
41e94a85 | 157 | { |
949b9325 | 158 | struct resource *res = &pgmap->res; |
966cf44f | 159 | struct dev_pagemap *conflict_pgmap; |
940519f0 MH |
160 | struct mhp_restrictions restrictions = { |
161 | /* | |
162 | * We do not want any optional features only our own memmap | |
7cc7867f | 163 | */ |
514caf23 | 164 | .altmap = pgmap_altmap(pgmap), |
940519f0 | 165 | }; |
9049771f | 166 | pgprot_t pgprot = PAGE_KERNEL; |
6869b7b2 | 167 | int error, is_ram; |
f6a55e1a | 168 | bool need_devmap_managed = true; |
5f29a77c | 169 | |
3ed2dcdf CH |
170 | switch (pgmap->type) { |
171 | case MEMORY_DEVICE_PRIVATE: | |
172 | if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) { | |
173 | WARN(1, "Device private memory not supported\n"); | |
174 | return ERR_PTR(-EINVAL); | |
175 | } | |
897e6365 CH |
176 | if (!pgmap->ops || !pgmap->ops->migrate_to_ram) { |
177 | WARN(1, "Missing migrate_to_ram method\n"); | |
178 | return ERR_PTR(-EINVAL); | |
179 | } | |
3ed2dcdf CH |
180 | break; |
181 | case MEMORY_DEVICE_FS_DAX: | |
182 | if (!IS_ENABLED(CONFIG_ZONE_DEVICE) || | |
183 | IS_ENABLED(CONFIG_FS_DAX_LIMITED)) { | |
184 | WARN(1, "File system DAX not supported\n"); | |
185 | return ERR_PTR(-EINVAL); | |
186 | } | |
187 | break; | |
188 | case MEMORY_DEVICE_DEVDAX: | |
189 | case MEMORY_DEVICE_PCI_P2PDMA: | |
f6a55e1a | 190 | need_devmap_managed = false; |
3ed2dcdf CH |
191 | break; |
192 | default: | |
193 | WARN(1, "Invalid pgmap type %d\n", pgmap->type); | |
194 | break; | |
195 | } | |
196 | ||
24917f6b CH |
197 | if (!pgmap->ref) { |
198 | if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup)) | |
199 | return ERR_PTR(-EINVAL); | |
200 | ||
201 | init_completion(&pgmap->done); | |
202 | error = percpu_ref_init(&pgmap->internal_ref, | |
203 | dev_pagemap_percpu_release, 0, GFP_KERNEL); | |
204 | if (error) | |
205 | return ERR_PTR(error); | |
206 | pgmap->ref = &pgmap->internal_ref; | |
207 | } else { | |
208 | if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) { | |
209 | WARN(1, "Missing reference count teardown definition\n"); | |
210 | return ERR_PTR(-EINVAL); | |
211 | } | |
50f44ee7 | 212 | } |
a95c90f1 | 213 | |
f6a55e1a | 214 | if (need_devmap_managed) { |
6f42193f | 215 | error = devmap_managed_enable_get(pgmap); |
f6a55e1a CH |
216 | if (error) |
217 | return ERR_PTR(error); | |
218 | } | |
219 | ||
7cc7867f | 220 | conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->start), NULL); |
15d36fec | 221 | if (conflict_pgmap) { |
6869b7b2 | 222 | WARN(1, "Conflicting mapping in same section\n"); |
15d36fec | 223 | put_dev_pagemap(conflict_pgmap); |
50f44ee7 DW |
224 | error = -ENOMEM; |
225 | goto err_array; | |
15d36fec DJ |
226 | } |
227 | ||
7cc7867f | 228 | conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->end), NULL); |
15d36fec | 229 | if (conflict_pgmap) { |
6869b7b2 | 230 | WARN(1, "Conflicting mapping in same section\n"); |
15d36fec | 231 | put_dev_pagemap(conflict_pgmap); |
50f44ee7 DW |
232 | error = -ENOMEM; |
233 | goto err_array; | |
15d36fec DJ |
234 | } |
235 | ||
7cc7867f | 236 | is_ram = region_intersects(res->start, resource_size(res), |
d37a14bb | 237 | IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); |
41e94a85 | 238 | |
06489cfb DW |
239 | if (is_ram != REGION_DISJOINT) { |
240 | WARN_ONCE(1, "%s attempted on %s region %pr\n", __func__, | |
241 | is_ram == REGION_MIXED ? "mixed" : "ram", res); | |
a95c90f1 DW |
242 | error = -ENXIO; |
243 | goto err_array; | |
41e94a85 CH |
244 | } |
245 | ||
bcfa4b72 MW |
246 | error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(res->start), |
247 | PHYS_PFN(res->end), pgmap, GFP_KERNEL)); | |
9476df7d | 248 | if (error) |
bcfa4b72 | 249 | goto err_array; |
9476df7d | 250 | |
41e94a85 | 251 | if (nid < 0) |
7eff93b7 | 252 | nid = numa_mem_id(); |
41e94a85 | 253 | |
7cc7867f DW |
254 | error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(res->start), 0, |
255 | resource_size(res)); | |
9049771f DW |
256 | if (error) |
257 | goto err_pfn_remap; | |
258 | ||
f931ab47 | 259 | mem_hotplug_begin(); |
69324b8f DW |
260 | |
261 | /* | |
262 | * For device private memory we call add_pages() as we only need to | |
263 | * allocate and initialize struct page for the device memory. More- | |
264 | * over the device memory is un-accessible thus we do not want to | |
265 | * create a linear mapping for the memory like arch_add_memory() | |
266 | * would do. | |
267 | * | |
268 | * For all other device memory types, which are accessible by | |
269 | * the CPU, we do want the linear mapping and thus use | |
270 | * arch_add_memory(). | |
271 | */ | |
272 | if (pgmap->type == MEMORY_DEVICE_PRIVATE) { | |
7cc7867f DW |
273 | error = add_pages(nid, PHYS_PFN(res->start), |
274 | PHYS_PFN(resource_size(res)), &restrictions); | |
69324b8f | 275 | } else { |
7cc7867f | 276 | error = kasan_add_zero_shadow(__va(res->start), resource_size(res)); |
69324b8f DW |
277 | if (error) { |
278 | mem_hotplug_done(); | |
279 | goto err_kasan; | |
280 | } | |
281 | ||
7cc7867f | 282 | error = arch_add_memory(nid, res->start, resource_size(res), |
940519f0 | 283 | &restrictions); |
69324b8f DW |
284 | } |
285 | ||
286 | if (!error) { | |
287 | struct zone *zone; | |
288 | ||
289 | zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE]; | |
7cc7867f DW |
290 | move_pfn_range_to_zone(zone, PHYS_PFN(res->start), |
291 | PHYS_PFN(resource_size(res)), restrictions.altmap); | |
0207df4f AR |
292 | } |
293 | ||
f931ab47 | 294 | mem_hotplug_done(); |
9476df7d DW |
295 | if (error) |
296 | goto err_add_memory; | |
41e94a85 | 297 | |
966cf44f AD |
298 | /* |
299 | * Initialization of the pages has been deferred until now in order | |
300 | * to allow us to do the work while not holding the hotplug lock. | |
301 | */ | |
302 | memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE], | |
7cc7867f DW |
303 | PHYS_PFN(res->start), |
304 | PHYS_PFN(resource_size(res)), pgmap); | |
966cf44f | 305 | percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap)); |
41e94a85 | 306 | return __va(res->start); |
9476df7d DW |
307 | |
308 | err_add_memory: | |
7cc7867f | 309 | kasan_remove_zero_shadow(__va(res->start), resource_size(res)); |
0207df4f | 310 | err_kasan: |
7cc7867f | 311 | untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res)); |
9049771f | 312 | err_pfn_remap: |
bcfa4b72 MW |
313 | pgmap_array_delete(res); |
314 | err_array: | |
24917f6b CH |
315 | dev_pagemap_kill(pgmap); |
316 | dev_pagemap_cleanup(pgmap); | |
6f42193f | 317 | devmap_managed_enable_put(); |
9476df7d | 318 | return ERR_PTR(error); |
41e94a85 | 319 | } |
6869b7b2 CH |
320 | EXPORT_SYMBOL_GPL(memremap_pages); |
321 | ||
322 | /** | |
323 | * devm_memremap_pages - remap and provide memmap backing for the given resource | |
324 | * @dev: hosting device for @res | |
325 | * @pgmap: pointer to a struct dev_pagemap | |
326 | * | |
327 | * Notes: | |
328 | * 1/ At a minimum the res and type members of @pgmap must be initialized | |
329 | * by the caller before passing it to this function | |
330 | * | |
331 | * 2/ The altmap field may optionally be initialized, in which case | |
332 | * PGMAP_ALTMAP_VALID must be set in pgmap->flags. | |
333 | * | |
334 | * 3/ The ref field may optionally be provided, in which pgmap->ref must be | |
335 | * 'live' on entry and will be killed and reaped at | |
336 | * devm_memremap_pages_release() time, or if this routine fails. | |
337 | * | |
338 | * 4/ res is expected to be a host memory range that could feasibly be | |
339 | * treated as a "System RAM" range, i.e. not a device mmio range, but | |
340 | * this is not enforced. | |
341 | */ | |
342 | void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) | |
343 | { | |
344 | int error; | |
345 | void *ret; | |
346 | ||
347 | ret = memremap_pages(pgmap, dev_to_node(dev)); | |
348 | if (IS_ERR(ret)) | |
349 | return ret; | |
350 | ||
351 | error = devm_add_action_or_reset(dev, devm_memremap_pages_release, | |
352 | pgmap); | |
353 | if (error) | |
354 | return ERR_PTR(error); | |
355 | return ret; | |
356 | } | |
808153e1 | 357 | EXPORT_SYMBOL_GPL(devm_memremap_pages); |
4b94ffdc | 358 | |
2e3f139e DW |
359 | void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap) |
360 | { | |
361 | devm_release_action(dev, devm_memremap_pages_release, pgmap); | |
362 | } | |
363 | EXPORT_SYMBOL_GPL(devm_memunmap_pages); | |
364 | ||
4b94ffdc DW |
365 | unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) |
366 | { | |
367 | /* number of pfns from base where pfn_to_page() is valid */ | |
514caf23 CH |
368 | if (altmap) |
369 | return altmap->reserve + altmap->free; | |
370 | return 0; | |
4b94ffdc DW |
371 | } |
372 | ||
373 | void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns) | |
374 | { | |
375 | altmap->alloc -= nr_pfns; | |
376 | } | |
377 | ||
0822acb8 CH |
378 | /** |
379 | * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn | |
380 | * @pfn: page frame number to lookup page_map | |
381 | * @pgmap: optional known pgmap that already has a reference | |
382 | * | |
832d7aa0 CH |
383 | * If @pgmap is non-NULL and covers @pfn it will be returned as-is. If @pgmap |
384 | * is non-NULL but does not cover @pfn the reference to it will be released. | |
0822acb8 CH |
385 | */ |
386 | struct dev_pagemap *get_dev_pagemap(unsigned long pfn, | |
387 | struct dev_pagemap *pgmap) | |
388 | { | |
0822acb8 CH |
389 | resource_size_t phys = PFN_PHYS(pfn); |
390 | ||
391 | /* | |
832d7aa0 | 392 | * In the cached case we're already holding a live reference. |
0822acb8 | 393 | */ |
832d7aa0 | 394 | if (pgmap) { |
e7744aa2 | 395 | if (phys >= pgmap->res.start && phys <= pgmap->res.end) |
832d7aa0 CH |
396 | return pgmap; |
397 | put_dev_pagemap(pgmap); | |
0822acb8 CH |
398 | } |
399 | ||
400 | /* fall back to slow path lookup */ | |
401 | rcu_read_lock(); | |
bcfa4b72 | 402 | pgmap = xa_load(&pgmap_array, PHYS_PFN(phys)); |
0822acb8 CH |
403 | if (pgmap && !percpu_ref_tryget_live(pgmap->ref)) |
404 | pgmap = NULL; | |
405 | rcu_read_unlock(); | |
406 | ||
407 | return pgmap; | |
408 | } | |
e7638488 | 409 | EXPORT_SYMBOL_GPL(get_dev_pagemap); |
7b2d55d2 | 410 | |
e7638488 | 411 | #ifdef CONFIG_DEV_PAGEMAP_OPS |
e7638488 | 412 | void __put_devmap_managed_page(struct page *page) |
7b2d55d2 JG |
413 | { |
414 | int count = page_ref_dec_return(page); | |
415 | ||
416 | /* | |
417 | * If refcount is 1 then page is freed and refcount is stable as nobody | |
418 | * holds a reference on the page. | |
419 | */ | |
420 | if (count == 1) { | |
421 | /* Clear Active bit in case of parallel mark_page_accessed */ | |
422 | __ClearPageActive(page); | |
423 | __ClearPageWaiters(page); | |
424 | ||
c733a828 | 425 | mem_cgroup_uncharge(page); |
7b2d55d2 | 426 | |
7ab0ad0e RC |
427 | /* |
428 | * When a device_private page is freed, the page->mapping field | |
429 | * may still contain a (stale) mapping value. For example, the | |
430 | * lower bits of page->mapping may still identify the page as | |
431 | * an anonymous page. Ultimately, this entire field is just | |
432 | * stale and wrong, and it will cause errors if not cleared. | |
433 | * One example is: | |
434 | * | |
435 | * migrate_vma_pages() | |
436 | * migrate_vma_insert_page() | |
437 | * page_add_new_anon_rmap() | |
438 | * __page_set_anon_rmap() | |
439 | * ...checks page->mapping, via PageAnon(page) call, | |
440 | * and incorrectly concludes that the page is an | |
441 | * anonymous page. Therefore, it incorrectly, | |
442 | * silently fails to set up the new anon rmap. | |
443 | * | |
444 | * For other types of ZONE_DEVICE pages, migration is either | |
445 | * handled differently or not done at all, so there is no need | |
446 | * to clear page->mapping. | |
447 | */ | |
448 | if (is_device_private_page(page)) | |
449 | page->mapping = NULL; | |
450 | ||
80a72d0a | 451 | page->pgmap->ops->page_free(page); |
7b2d55d2 JG |
452 | } else if (!count) |
453 | __put_page(page); | |
454 | } | |
31c5bda3 | 455 | EXPORT_SYMBOL(__put_devmap_managed_page); |
e7638488 | 456 | #endif /* CONFIG_DEV_PAGEMAP_OPS */ |