Commit | Line | Data |
---|---|---|
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 | ||
24 | static void devmap_managed_enable_put(void *data) | |
25 | { | |
26 | if (atomic_dec_and_test(&devmap_managed_enable)) | |
27 | static_branch_disable(&devmap_managed_key); | |
28 | } | |
29 | ||
30 | static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgmap) | |
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); | |
39 | return devm_add_action_or_reset(dev, devmap_managed_enable_put, NULL); | |
40 | } | |
41 | #else | |
42 | static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgmap) | |
43 | { | |
44 | return -EINVAL; | |
45 | } | |
46 | #endif /* CONFIG_DEV_PAGEMAP_OPS */ | |
47 | ||
bcfa4b72 | 48 | static void pgmap_array_delete(struct resource *res) |
ab1b597e | 49 | { |
bcfa4b72 MW |
50 | xa_store_range(&pgmap_array, PHYS_PFN(res->start), PHYS_PFN(res->end), |
51 | NULL, GFP_KERNEL); | |
ab1b597e | 52 | synchronize_rcu(); |
9476df7d DW |
53 | } |
54 | ||
e7744aa2 | 55 | static unsigned long pfn_first(struct dev_pagemap *pgmap) |
5c2c2587 | 56 | { |
514caf23 CH |
57 | return (pgmap->res.start >> PAGE_SHIFT) + |
58 | vmem_altmap_offset(pgmap_altmap(pgmap)); | |
5c2c2587 DW |
59 | } |
60 | ||
e7744aa2 | 61 | static unsigned long pfn_end(struct dev_pagemap *pgmap) |
5c2c2587 | 62 | { |
e7744aa2 | 63 | const struct resource *res = &pgmap->res; |
5c2c2587 DW |
64 | |
65 | return (res->start + resource_size(res)) >> PAGE_SHIFT; | |
66 | } | |
67 | ||
949b9325 DW |
68 | static unsigned long pfn_next(unsigned long pfn) |
69 | { | |
70 | if (pfn % 1024 == 0) | |
71 | cond_resched(); | |
72 | return pfn + 1; | |
73 | } | |
74 | ||
5c2c2587 | 75 | #define for_each_device_pfn(pfn, map) \ |
949b9325 | 76 | for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn)) |
5c2c2587 | 77 | |
24917f6b CH |
78 | static void dev_pagemap_kill(struct dev_pagemap *pgmap) |
79 | { | |
80 | if (pgmap->ops && pgmap->ops->kill) | |
81 | pgmap->ops->kill(pgmap); | |
82 | else | |
83 | percpu_ref_kill(pgmap->ref); | |
84 | } | |
85 | ||
86 | static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) | |
87 | { | |
88 | if (pgmap->ops && pgmap->ops->cleanup) { | |
89 | pgmap->ops->cleanup(pgmap); | |
90 | } else { | |
91 | wait_for_completion(&pgmap->done); | |
92 | percpu_ref_exit(pgmap->ref); | |
93 | } | |
94 | } | |
95 | ||
e8d51348 | 96 | static void devm_memremap_pages_release(void *data) |
41e94a85 | 97 | { |
e7744aa2 | 98 | struct dev_pagemap *pgmap = data; |
e8d51348 | 99 | struct device *dev = pgmap->dev; |
e7744aa2 | 100 | struct resource *res = &pgmap->res; |
9476df7d | 101 | resource_size_t align_start, align_size; |
71389703 | 102 | unsigned long pfn; |
2c2a5af6 | 103 | int nid; |
71389703 | 104 | |
24917f6b | 105 | dev_pagemap_kill(pgmap); |
e7744aa2 | 106 | for_each_device_pfn(pfn, pgmap) |
71389703 | 107 | put_page(pfn_to_page(pfn)); |
24917f6b | 108 | dev_pagemap_cleanup(pgmap); |
9476df7d | 109 | |
41e94a85 | 110 | /* pages are dead and unused, undo the arch mapping */ |
9476df7d | 111 | align_start = res->start & ~(SECTION_SIZE - 1); |
10a0cd6e JS |
112 | align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) |
113 | - align_start; | |
b5d24fda | 114 | |
2c2a5af6 OS |
115 | nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT)); |
116 | ||
f931ab47 | 117 | mem_hotplug_begin(); |
69324b8f DW |
118 | if (pgmap->type == MEMORY_DEVICE_PRIVATE) { |
119 | pfn = align_start >> PAGE_SHIFT; | |
120 | __remove_pages(page_zone(pfn_to_page(pfn)), pfn, | |
121 | align_size >> PAGE_SHIFT, NULL); | |
122 | } else { | |
2c2a5af6 | 123 | arch_remove_memory(nid, align_start, align_size, |
514caf23 | 124 | pgmap_altmap(pgmap)); |
69324b8f DW |
125 | kasan_remove_zero_shadow(__va(align_start), align_size); |
126 | } | |
f931ab47 | 127 | mem_hotplug_done(); |
b5d24fda | 128 | |
9049771f | 129 | untrack_pfn(NULL, PHYS_PFN(align_start), align_size); |
bcfa4b72 | 130 | pgmap_array_delete(res); |
e7744aa2 LG |
131 | dev_WARN_ONCE(dev, pgmap->altmap.alloc, |
132 | "%s: failed to free all reserved pages\n", __func__); | |
9476df7d DW |
133 | } |
134 | ||
24917f6b CH |
135 | static void dev_pagemap_percpu_release(struct percpu_ref *ref) |
136 | { | |
137 | struct dev_pagemap *pgmap = | |
138 | container_of(ref, struct dev_pagemap, internal_ref); | |
139 | ||
140 | complete(&pgmap->done); | |
141 | } | |
142 | ||
4b94ffdc DW |
143 | /** |
144 | * devm_memremap_pages - remap and provide memmap backing for the given resource | |
145 | * @dev: hosting device for @res | |
a95c90f1 | 146 | * @pgmap: pointer to a struct dev_pagemap |
4b94ffdc | 147 | * |
5c2c2587 | 148 | * Notes: |
24917f6b CH |
149 | * 1/ At a minimum the res and type members of @pgmap must be initialized |
150 | * by the caller before passing it to this function | |
e8d51348 | 151 | * |
514caf23 CH |
152 | * 2/ The altmap field may optionally be initialized, in which case |
153 | * PGMAP_ALTMAP_VALID must be set in pgmap->flags. | |
e8d51348 | 154 | * |
24917f6b CH |
155 | * 3/ The ref field may optionally be provided, in which pgmap->ref must be |
156 | * 'live' on entry and will be killed and reaped at | |
157 | * devm_memremap_pages_release() time, or if this routine fails. | |
5c2c2587 | 158 | * |
e8d51348 | 159 | * 4/ res is expected to be a host memory range that could feasibly be |
5c2c2587 DW |
160 | * treated as a "System RAM" range, i.e. not a device mmio range, but |
161 | * this is not enforced. | |
4b94ffdc | 162 | */ |
e8d51348 | 163 | void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) |
41e94a85 | 164 | { |
ab1b597e | 165 | resource_size_t align_start, align_size, align_end; |
949b9325 | 166 | struct resource *res = &pgmap->res; |
966cf44f | 167 | struct dev_pagemap *conflict_pgmap; |
940519f0 MH |
168 | struct mhp_restrictions restrictions = { |
169 | /* | |
170 | * We do not want any optional features only our own memmap | |
171 | */ | |
514caf23 | 172 | .altmap = pgmap_altmap(pgmap), |
940519f0 | 173 | }; |
9049771f | 174 | pgprot_t pgprot = PAGE_KERNEL; |
949b9325 | 175 | int error, nid, is_ram; |
f6a55e1a | 176 | bool need_devmap_managed = true; |
5f29a77c | 177 | |
3ed2dcdf CH |
178 | switch (pgmap->type) { |
179 | case MEMORY_DEVICE_PRIVATE: | |
180 | if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) { | |
181 | WARN(1, "Device private memory not supported\n"); | |
182 | return ERR_PTR(-EINVAL); | |
183 | } | |
897e6365 CH |
184 | if (!pgmap->ops || !pgmap->ops->migrate_to_ram) { |
185 | WARN(1, "Missing migrate_to_ram method\n"); | |
186 | return ERR_PTR(-EINVAL); | |
187 | } | |
3ed2dcdf CH |
188 | break; |
189 | case MEMORY_DEVICE_FS_DAX: | |
190 | if (!IS_ENABLED(CONFIG_ZONE_DEVICE) || | |
191 | IS_ENABLED(CONFIG_FS_DAX_LIMITED)) { | |
192 | WARN(1, "File system DAX not supported\n"); | |
193 | return ERR_PTR(-EINVAL); | |
194 | } | |
195 | break; | |
196 | case MEMORY_DEVICE_DEVDAX: | |
197 | case MEMORY_DEVICE_PCI_P2PDMA: | |
f6a55e1a | 198 | need_devmap_managed = false; |
3ed2dcdf CH |
199 | break; |
200 | default: | |
201 | WARN(1, "Invalid pgmap type %d\n", pgmap->type); | |
202 | break; | |
203 | } | |
204 | ||
24917f6b CH |
205 | if (!pgmap->ref) { |
206 | if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup)) | |
207 | return ERR_PTR(-EINVAL); | |
208 | ||
209 | init_completion(&pgmap->done); | |
210 | error = percpu_ref_init(&pgmap->internal_ref, | |
211 | dev_pagemap_percpu_release, 0, GFP_KERNEL); | |
212 | if (error) | |
213 | return ERR_PTR(error); | |
214 | pgmap->ref = &pgmap->internal_ref; | |
215 | } else { | |
216 | if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) { | |
217 | WARN(1, "Missing reference count teardown definition\n"); | |
218 | return ERR_PTR(-EINVAL); | |
219 | } | |
50f44ee7 | 220 | } |
a95c90f1 | 221 | |
f6a55e1a CH |
222 | if (need_devmap_managed) { |
223 | error = devmap_managed_enable_get(dev, pgmap); | |
224 | if (error) | |
225 | return ERR_PTR(error); | |
226 | } | |
227 | ||
5f29a77c DW |
228 | align_start = res->start & ~(SECTION_SIZE - 1); |
229 | align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) | |
230 | - align_start; | |
15d36fec DJ |
231 | align_end = align_start + align_size - 1; |
232 | ||
233 | conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_start), NULL); | |
234 | if (conflict_pgmap) { | |
235 | dev_WARN(dev, "Conflicting mapping in same section\n"); | |
236 | put_dev_pagemap(conflict_pgmap); | |
50f44ee7 DW |
237 | error = -ENOMEM; |
238 | goto err_array; | |
15d36fec DJ |
239 | } |
240 | ||
241 | conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_end), NULL); | |
242 | if (conflict_pgmap) { | |
243 | dev_WARN(dev, "Conflicting mapping in same section\n"); | |
244 | put_dev_pagemap(conflict_pgmap); | |
50f44ee7 DW |
245 | error = -ENOMEM; |
246 | goto err_array; | |
15d36fec DJ |
247 | } |
248 | ||
d37a14bb LT |
249 | is_ram = region_intersects(align_start, align_size, |
250 | IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); | |
41e94a85 | 251 | |
06489cfb DW |
252 | if (is_ram != REGION_DISJOINT) { |
253 | WARN_ONCE(1, "%s attempted on %s region %pr\n", __func__, | |
254 | is_ram == REGION_MIXED ? "mixed" : "ram", res); | |
a95c90f1 DW |
255 | error = -ENXIO; |
256 | goto err_array; | |
41e94a85 CH |
257 | } |
258 | ||
4b94ffdc | 259 | pgmap->dev = dev; |
4b94ffdc | 260 | |
bcfa4b72 MW |
261 | error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(res->start), |
262 | PHYS_PFN(res->end), pgmap, GFP_KERNEL)); | |
9476df7d | 263 | if (error) |
bcfa4b72 | 264 | goto err_array; |
9476df7d | 265 | |
41e94a85 CH |
266 | nid = dev_to_node(dev); |
267 | if (nid < 0) | |
7eff93b7 | 268 | nid = numa_mem_id(); |
41e94a85 | 269 | |
9049771f DW |
270 | error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0, |
271 | align_size); | |
272 | if (error) | |
273 | goto err_pfn_remap; | |
274 | ||
f931ab47 | 275 | mem_hotplug_begin(); |
69324b8f DW |
276 | |
277 | /* | |
278 | * For device private memory we call add_pages() as we only need to | |
279 | * allocate and initialize struct page for the device memory. More- | |
280 | * over the device memory is un-accessible thus we do not want to | |
281 | * create a linear mapping for the memory like arch_add_memory() | |
282 | * would do. | |
283 | * | |
284 | * For all other device memory types, which are accessible by | |
285 | * the CPU, we do want the linear mapping and thus use | |
286 | * arch_add_memory(). | |
287 | */ | |
288 | if (pgmap->type == MEMORY_DEVICE_PRIVATE) { | |
289 | error = add_pages(nid, align_start >> PAGE_SHIFT, | |
940519f0 | 290 | align_size >> PAGE_SHIFT, &restrictions); |
69324b8f DW |
291 | } else { |
292 | error = kasan_add_zero_shadow(__va(align_start), align_size); | |
293 | if (error) { | |
294 | mem_hotplug_done(); | |
295 | goto err_kasan; | |
296 | } | |
297 | ||
940519f0 MH |
298 | error = arch_add_memory(nid, align_start, align_size, |
299 | &restrictions); | |
69324b8f DW |
300 | } |
301 | ||
302 | if (!error) { | |
303 | struct zone *zone; | |
304 | ||
305 | zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE]; | |
306 | move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT, | |
514caf23 | 307 | align_size >> PAGE_SHIFT, pgmap_altmap(pgmap)); |
0207df4f AR |
308 | } |
309 | ||
f931ab47 | 310 | mem_hotplug_done(); |
9476df7d DW |
311 | if (error) |
312 | goto err_add_memory; | |
41e94a85 | 313 | |
966cf44f AD |
314 | /* |
315 | * Initialization of the pages has been deferred until now in order | |
316 | * to allow us to do the work while not holding the hotplug lock. | |
317 | */ | |
318 | memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE], | |
319 | align_start >> PAGE_SHIFT, | |
320 | align_size >> PAGE_SHIFT, pgmap); | |
321 | percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap)); | |
e8d51348 | 322 | |
a95c90f1 DW |
323 | error = devm_add_action_or_reset(dev, devm_memremap_pages_release, |
324 | pgmap); | |
325 | if (error) | |
326 | return ERR_PTR(error); | |
e8d51348 | 327 | |
41e94a85 | 328 | return __va(res->start); |
9476df7d DW |
329 | |
330 | err_add_memory: | |
0207df4f AR |
331 | kasan_remove_zero_shadow(__va(align_start), align_size); |
332 | err_kasan: | |
9049771f DW |
333 | untrack_pfn(NULL, PHYS_PFN(align_start), align_size); |
334 | err_pfn_remap: | |
bcfa4b72 MW |
335 | pgmap_array_delete(res); |
336 | err_array: | |
24917f6b CH |
337 | dev_pagemap_kill(pgmap); |
338 | dev_pagemap_cleanup(pgmap); | |
9476df7d | 339 | return ERR_PTR(error); |
41e94a85 | 340 | } |
808153e1 | 341 | EXPORT_SYMBOL_GPL(devm_memremap_pages); |
4b94ffdc | 342 | |
2e3f139e DW |
343 | void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap) |
344 | { | |
345 | devm_release_action(dev, devm_memremap_pages_release, pgmap); | |
346 | } | |
347 | EXPORT_SYMBOL_GPL(devm_memunmap_pages); | |
348 | ||
4b94ffdc DW |
349 | unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) |
350 | { | |
351 | /* number of pfns from base where pfn_to_page() is valid */ | |
514caf23 CH |
352 | if (altmap) |
353 | return altmap->reserve + altmap->free; | |
354 | return 0; | |
4b94ffdc DW |
355 | } |
356 | ||
357 | void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns) | |
358 | { | |
359 | altmap->alloc -= nr_pfns; | |
360 | } | |
361 | ||
0822acb8 CH |
362 | /** |
363 | * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn | |
364 | * @pfn: page frame number to lookup page_map | |
365 | * @pgmap: optional known pgmap that already has a reference | |
366 | * | |
832d7aa0 CH |
367 | * If @pgmap is non-NULL and covers @pfn it will be returned as-is. If @pgmap |
368 | * is non-NULL but does not cover @pfn the reference to it will be released. | |
0822acb8 CH |
369 | */ |
370 | struct dev_pagemap *get_dev_pagemap(unsigned long pfn, | |
371 | struct dev_pagemap *pgmap) | |
372 | { | |
0822acb8 CH |
373 | resource_size_t phys = PFN_PHYS(pfn); |
374 | ||
375 | /* | |
832d7aa0 | 376 | * In the cached case we're already holding a live reference. |
0822acb8 | 377 | */ |
832d7aa0 | 378 | if (pgmap) { |
e7744aa2 | 379 | if (phys >= pgmap->res.start && phys <= pgmap->res.end) |
832d7aa0 CH |
380 | return pgmap; |
381 | put_dev_pagemap(pgmap); | |
0822acb8 CH |
382 | } |
383 | ||
384 | /* fall back to slow path lookup */ | |
385 | rcu_read_lock(); | |
bcfa4b72 | 386 | pgmap = xa_load(&pgmap_array, PHYS_PFN(phys)); |
0822acb8 CH |
387 | if (pgmap && !percpu_ref_tryget_live(pgmap->ref)) |
388 | pgmap = NULL; | |
389 | rcu_read_unlock(); | |
390 | ||
391 | return pgmap; | |
392 | } | |
e7638488 | 393 | EXPORT_SYMBOL_GPL(get_dev_pagemap); |
7b2d55d2 | 394 | |
e7638488 | 395 | #ifdef CONFIG_DEV_PAGEMAP_OPS |
e7638488 | 396 | void __put_devmap_managed_page(struct page *page) |
7b2d55d2 JG |
397 | { |
398 | int count = page_ref_dec_return(page); | |
399 | ||
400 | /* | |
401 | * If refcount is 1 then page is freed and refcount is stable as nobody | |
402 | * holds a reference on the page. | |
403 | */ | |
404 | if (count == 1) { | |
405 | /* Clear Active bit in case of parallel mark_page_accessed */ | |
406 | __ClearPageActive(page); | |
407 | __ClearPageWaiters(page); | |
408 | ||
c733a828 | 409 | mem_cgroup_uncharge(page); |
7b2d55d2 | 410 | |
80a72d0a | 411 | page->pgmap->ops->page_free(page); |
7b2d55d2 JG |
412 | } else if (!count) |
413 | __put_page(page); | |
414 | } | |
31c5bda3 | 415 | EXPORT_SYMBOL(__put_devmap_managed_page); |
e7638488 | 416 | #endif /* CONFIG_DEV_PAGEMAP_OPS */ |