blob: 066e73c2fcc9dbbd89c13923e203ed47aaff7d58 [file] [log] [blame]
Dan Williams92281dee2015-08-10 23:07:06 -04001/*
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 */
Dan Williams9476df72016-01-15 16:56:19 -080013#include <linux/radix-tree.h>
14#include <linux/memremap.h>
Christoph Hellwig7d3dcf22015-08-10 23:07:07 -040015#include <linux/device.h>
Dan Williams92281dee2015-08-10 23:07:06 -040016#include <linux/types.h>
Dan Williams34c0fd52016-01-15 16:56:14 -080017#include <linux/pfn_t.h>
Dan Williams92281dee2015-08-10 23:07:06 -040018#include <linux/io.h>
19#include <linux/mm.h>
Christoph Hellwig41e94a82015-08-17 16:00:35 +020020#include <linux/memory_hotplug.h>
Dan Williams92281dee2015-08-10 23:07:06 -040021
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
Ard Biesheuvelc269cba2016-02-22 15:02:07 +010030#ifndef arch_memremap_wb
31static void *arch_memremap_wb(resource_size_t offset, unsigned long size)
32{
33 return (__force void *)ioremap_cache(offset, size);
34}
35#endif
36
Tom Lendacky8f716c92017-07-17 16:10:16 -050037#ifndef arch_memremap_can_ram_remap
38static bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
39 unsigned long flags)
40{
41 return true;
42}
43#endif
44
45static void *try_ram_remap(resource_size_t offset, size_t size,
46 unsigned long flags)
Dan Williams182475b2015-10-26 16:55:56 -040047{
Ard Biesheuvelac343e82016-03-09 14:08:32 -080048 unsigned long pfn = PHYS_PFN(offset);
Dan Williams182475b2015-10-26 16:55:56 -040049
50 /* In the simple case just return the existing linear address */
Tom Lendacky8f716c92017-07-17 16:10:16 -050051 if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn)) &&
52 arch_memremap_can_ram_remap(offset, size, flags))
Dan Williams182475b2015-10-26 16:55:56 -040053 return __va(offset);
Tom Lendacky8f716c92017-07-17 16:10:16 -050054
Ard Biesheuvelc269cba2016-02-22 15:02:07 +010055 return NULL; /* fallback to arch_memremap_wb */
Dan Williams182475b2015-10-26 16:55:56 -040056}
57
Dan Williams92281dee2015-08-10 23:07:06 -040058/**
59 * memremap() - remap an iomem_resource as cacheable memory
60 * @offset: iomem resource start address
61 * @size: size of remap
Tom Lendacky8f716c92017-07-17 16:10:16 -050062 * @flags: any of MEMREMAP_WB, MEMREMAP_WT, MEMREMAP_WC,
63 * MEMREMAP_ENC, MEMREMAP_DEC
Dan Williams92281dee2015-08-10 23:07:06 -040064 *
65 * memremap() is "ioremap" for cases where it is known that the resource
66 * being mapped does not have i/o side effects and the __iomem
Brian Starkeyc907e0e2016-03-22 14:28:00 -070067 * annotation is not applicable. In the case of multiple flags, the different
68 * mapping types will be attempted in the order listed below until one of
69 * them succeeds.
Dan Williams92281dee2015-08-10 23:07:06 -040070 *
Toshi Kani1c29f252016-01-26 21:57:28 +010071 * MEMREMAP_WB - matches the default mapping for System RAM on
Dan Williams92281dee2015-08-10 23:07:06 -040072 * the architecture. This is usually a read-allocate write-back cache.
73 * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM
74 * memremap() will bypass establishing a new mapping and instead return
75 * a pointer into the direct map.
76 *
77 * MEMREMAP_WT - establish a mapping whereby writes either bypass the
78 * cache or are written through to memory and never exist in a
79 * cache-dirty state with respect to program visibility. Attempts to
Toshi Kani1c29f252016-01-26 21:57:28 +010080 * map System RAM with this mapping type will fail.
Brian Starkeyc907e0e2016-03-22 14:28:00 -070081 *
82 * MEMREMAP_WC - establish a writecombine mapping, whereby writes may
83 * be coalesced together (e.g. in the CPU's write buffers), but is otherwise
84 * uncached. Attempts to map System RAM with this mapping type will fail.
Dan Williams92281dee2015-08-10 23:07:06 -040085 */
86void *memremap(resource_size_t offset, size_t size, unsigned long flags)
87{
Toshi Kani1c29f252016-01-26 21:57:28 +010088 int is_ram = region_intersects(offset, size,
89 IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
Dan Williams92281dee2015-08-10 23:07:06 -040090 void *addr = NULL;
91
Brian Starkeycf61e2a2016-03-22 14:27:57 -070092 if (!flags)
93 return NULL;
94
Dan Williams92281dee2015-08-10 23:07:06 -040095 if (is_ram == REGION_MIXED) {
96 WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n",
97 &offset, (unsigned long) size);
98 return NULL;
99 }
100
101 /* Try all mapping types requested until one returns non-NULL */
102 if (flags & MEMREMAP_WB) {
Dan Williams92281dee2015-08-10 23:07:06 -0400103 /*
104 * MEMREMAP_WB is special in that it can be satisifed
105 * from the direct map. Some archs depend on the
106 * capability of memremap() to autodetect cases where
Toshi Kani1c29f252016-01-26 21:57:28 +0100107 * the requested range is potentially in System RAM.
Dan Williams92281dee2015-08-10 23:07:06 -0400108 */
109 if (is_ram == REGION_INTERSECTS)
Tom Lendacky8f716c92017-07-17 16:10:16 -0500110 addr = try_ram_remap(offset, size, flags);
Dan Williams182475b2015-10-26 16:55:56 -0400111 if (!addr)
Ard Biesheuvelc269cba2016-02-22 15:02:07 +0100112 addr = arch_memremap_wb(offset, size);
Dan Williams92281dee2015-08-10 23:07:06 -0400113 }
114
115 /*
Brian Starkeycf61e2a2016-03-22 14:27:57 -0700116 * If we don't have a mapping yet and other request flags are
117 * present then we will be attempting to establish a new virtual
Dan Williams92281dee2015-08-10 23:07:06 -0400118 * address mapping. Enforce that this mapping is not aliasing
Toshi Kani1c29f252016-01-26 21:57:28 +0100119 * System RAM.
Dan Williams92281dee2015-08-10 23:07:06 -0400120 */
Brian Starkeycf61e2a2016-03-22 14:27:57 -0700121 if (!addr && is_ram == REGION_INTERSECTS && flags != MEMREMAP_WB) {
Dan Williams92281dee2015-08-10 23:07:06 -0400122 WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",
123 &offset, (unsigned long) size);
124 return NULL;
125 }
126
Brian Starkeycf61e2a2016-03-22 14:27:57 -0700127 if (!addr && (flags & MEMREMAP_WT))
Dan Williams92281dee2015-08-10 23:07:06 -0400128 addr = ioremap_wt(offset, size);
Dan Williams92281dee2015-08-10 23:07:06 -0400129
Brian Starkeyc907e0e2016-03-22 14:28:00 -0700130 if (!addr && (flags & MEMREMAP_WC))
131 addr = ioremap_wc(offset, size);
132
Dan Williams92281dee2015-08-10 23:07:06 -0400133 return addr;
134}
135EXPORT_SYMBOL(memremap);
136
137void memunmap(void *addr)
138{
139 if (is_vmalloc_addr(addr))
140 iounmap((void __iomem *) addr);
141}
142EXPORT_SYMBOL(memunmap);
Christoph Hellwig7d3dcf22015-08-10 23:07:07 -0400143
144static void devm_memremap_release(struct device *dev, void *res)
145{
Toshi Kani9273a8b2016-02-17 13:11:29 -0800146 memunmap(*(void **)res);
Christoph Hellwig7d3dcf22015-08-10 23:07:07 -0400147}
148
149static int devm_memremap_match(struct device *dev, void *res, void *match_data)
150{
151 return *(void **)res == match_data;
152}
153
154void *devm_memremap(struct device *dev, resource_size_t offset,
155 size_t size, unsigned long flags)
156{
157 void **ptr, *addr;
158
Dan Williams538ea4a2015-10-05 20:35:56 -0400159 ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL,
160 dev_to_node(dev));
Christoph Hellwig7d3dcf22015-08-10 23:07:07 -0400161 if (!ptr)
Dan Williamsb36f4762015-09-15 02:42:20 -0400162 return ERR_PTR(-ENOMEM);
Christoph Hellwig7d3dcf22015-08-10 23:07:07 -0400163
164 addr = memremap(offset, size, flags);
165 if (addr) {
166 *ptr = addr;
167 devres_add(dev, ptr);
Toshi Kani93f834d2016-02-20 14:32:24 -0800168 } else {
Christoph Hellwig7d3dcf22015-08-10 23:07:07 -0400169 devres_free(ptr);
Toshi Kani93f834d2016-02-20 14:32:24 -0800170 return ERR_PTR(-ENXIO);
171 }
Christoph Hellwig7d3dcf22015-08-10 23:07:07 -0400172
173 return addr;
174}
175EXPORT_SYMBOL(devm_memremap);
176
177void devm_memunmap(struct device *dev, void *addr)
178{
Dan Williamsd7413142015-09-15 02:37:48 -0400179 WARN_ON(devres_release(dev, devm_memremap_release,
180 devm_memremap_match, addr));
Christoph Hellwig7d3dcf22015-08-10 23:07:07 -0400181}
182EXPORT_SYMBOL(devm_memunmap);
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200183
184#ifdef CONFIG_ZONE_DEVICE
Dan Williams9476df72016-01-15 16:56:19 -0800185static DEFINE_MUTEX(pgmap_lock);
186static RADIX_TREE(pgmap_radix, GFP_KERNEL);
187#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)
188#define SECTION_SIZE (1UL << PA_SECTION_SHIFT)
189
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200190struct page_map {
191 struct resource res;
Dan Williams9476df72016-01-15 16:56:19 -0800192 struct percpu_ref *ref;
193 struct dev_pagemap pgmap;
Dan Williams4b94ffd2016-01-15 16:56:22 -0800194 struct vmem_altmap altmap;
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200195};
196
Dan Williamsab1b5972017-09-06 16:24:13 -0700197static unsigned long order_at(struct resource *res, unsigned long pgoff)
198{
199 unsigned long phys_pgoff = PHYS_PFN(res->start) + pgoff;
200 unsigned long nr_pages, mask;
201
202 nr_pages = PHYS_PFN(resource_size(res));
203 if (nr_pages == pgoff)
204 return ULONG_MAX;
205
206 /*
207 * What is the largest aligned power-of-2 range available from
208 * this resource pgoff to the end of the resource range,
209 * considering the alignment of the current pgoff?
210 */
211 mask = phys_pgoff | rounddown_pow_of_two(nr_pages - pgoff);
212 if (!mask)
213 return ULONG_MAX;
214
215 return find_first_bit(&mask, BITS_PER_LONG);
216}
217
218#define foreach_order_pgoff(res, order, pgoff) \
219 for (pgoff = 0, order = order_at((res), pgoff); order < ULONG_MAX; \
220 pgoff += 1UL << order, order = order_at((res), pgoff))
221
Dan Williams9476df72016-01-15 16:56:19 -0800222static void pgmap_radix_release(struct resource *res)
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200223{
Dan Williamsab1b5972017-09-06 16:24:13 -0700224 unsigned long pgoff, order;
Dan Williams9476df72016-01-15 16:56:19 -0800225
226 mutex_lock(&pgmap_lock);
Dan Williamsab1b5972017-09-06 16:24:13 -0700227 foreach_order_pgoff(res, order, pgoff)
228 radix_tree_delete(&pgmap_radix, PHYS_PFN(res->start) + pgoff);
Dan Williams9476df72016-01-15 16:56:19 -0800229 mutex_unlock(&pgmap_lock);
Dan Williamsab1b5972017-09-06 16:24:13 -0700230
231 synchronize_rcu();
Dan Williams9476df72016-01-15 16:56:19 -0800232}
233
Dan Williams5c2c2582016-01-15 16:56:49 -0800234static unsigned long pfn_first(struct page_map *page_map)
235{
236 struct dev_pagemap *pgmap = &page_map->pgmap;
237 const struct resource *res = &page_map->res;
238 struct vmem_altmap *altmap = pgmap->altmap;
239 unsigned long pfn;
240
241 pfn = res->start >> PAGE_SHIFT;
242 if (altmap)
243 pfn += vmem_altmap_offset(altmap);
244 return pfn;
245}
246
247static unsigned long pfn_end(struct page_map *page_map)
248{
249 const struct resource *res = &page_map->res;
250
251 return (res->start + resource_size(res)) >> PAGE_SHIFT;
252}
253
254#define for_each_device_pfn(pfn, map) \
255 for (pfn = pfn_first(map); pfn < pfn_end(map); pfn++)
256
Dan Williams9476df72016-01-15 16:56:19 -0800257static void devm_memremap_pages_release(struct device *dev, void *data)
258{
259 struct page_map *page_map = data;
260 struct resource *res = &page_map->res;
261 resource_size_t align_start, align_size;
Dan Williams4b94ffd2016-01-15 16:56:22 -0800262 struct dev_pagemap *pgmap = &page_map->pgmap;
Dan Williams71389702017-04-28 10:23:37 -0700263 unsigned long pfn;
264
265 for_each_device_pfn(pfn, page_map)
266 put_page(pfn_to_page(pfn));
Dan Williams9476df72016-01-15 16:56:19 -0800267
Dan Williams5c2c2582016-01-15 16:56:49 -0800268 if (percpu_ref_tryget_live(pgmap->ref)) {
269 dev_WARN(dev, "%s: page mapping is still live!\n", __func__);
270 percpu_ref_put(pgmap->ref);
271 }
272
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200273 /* pages are dead and unused, undo the arch mapping */
Dan Williams9476df72016-01-15 16:56:19 -0800274 align_start = res->start & ~(SECTION_SIZE - 1);
275 align_size = ALIGN(resource_size(res), SECTION_SIZE);
Dan Williamsb5d24fd2017-02-24 14:55:45 -0800276
Dan Williamsf931ab42017-01-10 16:57:36 -0800277 mem_hotplug_begin();
Dan Williams9476df72016-01-15 16:56:19 -0800278 arch_remove_memory(align_start, align_size);
Dan Williamsf931ab42017-01-10 16:57:36 -0800279 mem_hotplug_done();
Dan Williamsb5d24fd2017-02-24 14:55:45 -0800280
Dan Williams90497712016-09-07 08:51:21 -0700281 untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
Dan Williamseb7d78c2016-01-29 21:48:34 -0800282 pgmap_radix_release(res);
Dan Williams4b94ffd2016-01-15 16:56:22 -0800283 dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc,
284 "%s: failed to free all reserved pages\n", __func__);
Dan Williams9476df72016-01-15 16:56:19 -0800285}
286
287/* assumes rcu_read_lock() held at entry */
288struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
289{
290 struct page_map *page_map;
291
292 WARN_ON_ONCE(!rcu_read_lock_held());
293
Dan Williamsab1b5972017-09-06 16:24:13 -0700294 page_map = radix_tree_lookup(&pgmap_radix, PHYS_PFN(phys));
Dan Williams9476df72016-01-15 16:56:19 -0800295 return page_map ? &page_map->pgmap : NULL;
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200296}
297
Dan Williams4b94ffd2016-01-15 16:56:22 -0800298/**
299 * devm_memremap_pages - remap and provide memmap backing for the given resource
300 * @dev: hosting device for @res
301 * @res: "host memory" address range
Dan Williams5c2c2582016-01-15 16:56:49 -0800302 * @ref: a live per-cpu reference count
Dan Williams4b94ffd2016-01-15 16:56:22 -0800303 * @altmap: optional descriptor for allocating the memmap from @res
304 *
Dan Williams5c2c2582016-01-15 16:56:49 -0800305 * Notes:
306 * 1/ @ref must be 'live' on entry and 'dead' before devm_memunmap_pages() time
Dan Williams71389702017-04-28 10:23:37 -0700307 * (or devm release event). The expected order of events is that @ref has
308 * been through percpu_ref_kill() before devm_memremap_pages_release(). The
309 * wait for the completion of all references being dropped and
310 * percpu_ref_exit() must occur after devm_memremap_pages_release().
Dan Williams5c2c2582016-01-15 16:56:49 -0800311 *
312 * 2/ @res is expected to be a host memory range that could feasibly be
313 * treated as a "System RAM" range, i.e. not a device mmio range, but
314 * this is not enforced.
Dan Williams4b94ffd2016-01-15 16:56:22 -0800315 */
316void *devm_memremap_pages(struct device *dev, struct resource *res,
Dan Williams5c2c2582016-01-15 16:56:49 -0800317 struct percpu_ref *ref, struct vmem_altmap *altmap)
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200318{
Dan Williamsab1b5972017-09-06 16:24:13 -0700319 resource_size_t align_start, align_size, align_end;
320 unsigned long pfn, pgoff, order;
Dan Williams90497712016-09-07 08:51:21 -0700321 pgprot_t pgprot = PAGE_KERNEL;
Dan Williams4b94ffd2016-01-15 16:56:22 -0800322 struct dev_pagemap *pgmap;
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200323 struct page_map *page_map;
Dan Williams5f29a772016-03-09 14:08:13 -0800324 int error, nid, is_ram;
Dan Williams5f29a772016-03-09 14:08:13 -0800325
326 align_start = res->start & ~(SECTION_SIZE - 1);
327 align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
328 - align_start;
Linus Torvaldsd37a14bb2016-03-14 15:15:51 -0700329 is_ram = region_intersects(align_start, align_size,
330 IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200331
332 if (is_ram == REGION_MIXED) {
333 WARN_ONCE(1, "%s attempted on mixed region %pr\n",
334 __func__, res);
335 return ERR_PTR(-ENXIO);
336 }
337
338 if (is_ram == REGION_INTERSECTS)
339 return __va(res->start);
340
Dan Williams5c2c2582016-01-15 16:56:49 -0800341 if (!ref)
342 return ERR_PTR(-EINVAL);
343
Dan Williams538ea4a2015-10-05 20:35:56 -0400344 page_map = devres_alloc_node(devm_memremap_pages_release,
345 sizeof(*page_map), GFP_KERNEL, dev_to_node(dev));
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200346 if (!page_map)
347 return ERR_PTR(-ENOMEM);
Dan Williams4b94ffd2016-01-15 16:56:22 -0800348 pgmap = &page_map->pgmap;
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200349
350 memcpy(&page_map->res, res, sizeof(*res));
351
Dan Williams4b94ffd2016-01-15 16:56:22 -0800352 pgmap->dev = dev;
353 if (altmap) {
354 memcpy(&page_map->altmap, altmap, sizeof(*altmap));
355 pgmap->altmap = &page_map->altmap;
356 }
Dan Williams5c2c2582016-01-15 16:56:49 -0800357 pgmap->ref = ref;
Dan Williams4b94ffd2016-01-15 16:56:22 -0800358 pgmap->res = &page_map->res;
359
Dan Williams9476df72016-01-15 16:56:19 -0800360 mutex_lock(&pgmap_lock);
361 error = 0;
Dan Williamseb7d78c2016-01-29 21:48:34 -0800362 align_end = align_start + align_size - 1;
Dan Williamsab1b5972017-09-06 16:24:13 -0700363
364 foreach_order_pgoff(res, order, pgoff) {
Dan Williams9476df72016-01-15 16:56:19 -0800365 struct dev_pagemap *dup;
366
367 rcu_read_lock();
Dan Williamsab1b5972017-09-06 16:24:13 -0700368 dup = find_dev_pagemap(res->start + PFN_PHYS(pgoff));
Dan Williams9476df72016-01-15 16:56:19 -0800369 rcu_read_unlock();
370 if (dup) {
371 dev_err(dev, "%s: %pr collides with mapping for %s\n",
372 __func__, res, dev_name(dup->dev));
373 error = -EBUSY;
374 break;
375 }
Dan Williamsab1b5972017-09-06 16:24:13 -0700376 error = __radix_tree_insert(&pgmap_radix,
377 PHYS_PFN(res->start) + pgoff, order, page_map);
Dan Williams9476df72016-01-15 16:56:19 -0800378 if (error) {
379 dev_err(dev, "%s: failed: %d\n", __func__, error);
380 break;
381 }
382 }
383 mutex_unlock(&pgmap_lock);
384 if (error)
385 goto err_radix;
386
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200387 nid = dev_to_node(dev);
388 if (nid < 0)
Dan Williams7eff93b2015-10-05 20:35:55 -0400389 nid = numa_mem_id();
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200390
Dan Williams90497712016-09-07 08:51:21 -0700391 error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0,
392 align_size);
393 if (error)
394 goto err_pfn_remap;
395
Dan Williamsf931ab42017-01-10 16:57:36 -0800396 mem_hotplug_begin();
Michal Hocko3d79a722017-07-06 15:38:21 -0700397 error = arch_add_memory(nid, align_start, align_size, false);
Michal Hockof1dd2cd2017-07-06 15:38:11 -0700398 if (!error)
399 move_pfn_range_to_zone(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
400 align_start >> PAGE_SHIFT,
401 align_size >> PAGE_SHIFT);
Dan Williamsf931ab42017-01-10 16:57:36 -0800402 mem_hotplug_done();
Dan Williams9476df72016-01-15 16:56:19 -0800403 if (error)
404 goto err_add_memory;
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200405
Dan Williams5c2c2582016-01-15 16:56:49 -0800406 for_each_device_pfn(pfn, page_map) {
407 struct page *page = pfn_to_page(pfn);
408
Dan Williamsd77a1172016-03-09 14:08:10 -0800409 /*
410 * ZONE_DEVICE pages union ->lru with a ->pgmap back
411 * pointer. It is a bug if a ZONE_DEVICE page is ever
412 * freed or placed on a driver-private list. Seed the
413 * storage with LIST_POISON* values.
414 */
415 list_del(&page->lru);
Dan Williams5c2c2582016-01-15 16:56:49 -0800416 page->pgmap = pgmap;
Dan Williams71389702017-04-28 10:23:37 -0700417 percpu_ref_get(ref);
Dan Williams5c2c2582016-01-15 16:56:49 -0800418 }
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200419 devres_add(dev, page_map);
420 return __va(res->start);
Dan Williams9476df72016-01-15 16:56:19 -0800421
422 err_add_memory:
Dan Williams90497712016-09-07 08:51:21 -0700423 untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
424 err_pfn_remap:
Dan Williams9476df72016-01-15 16:56:19 -0800425 err_radix:
426 pgmap_radix_release(res);
427 devres_free(page_map);
428 return ERR_PTR(error);
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200429}
430EXPORT_SYMBOL(devm_memremap_pages);
Dan Williams4b94ffd2016-01-15 16:56:22 -0800431
432unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
433{
434 /* number of pfns from base where pfn_to_page() is valid */
435 return altmap->reserve + altmap->free;
436}
437
438void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns)
439{
440 altmap->alloc -= nr_pfns;
441}
442
Dan Williams4b94ffd2016-01-15 16:56:22 -0800443struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
444{
445 /*
446 * 'memmap_start' is the virtual address for the first "struct
447 * page" in this range of the vmemmap array. In the case of
Andreas Ziegler07061aa2016-03-15 14:55:33 -0700448 * CONFIG_SPARSEMEM_VMEMMAP a page_to_pfn conversion is simple
Dan Williams4b94ffd2016-01-15 16:56:22 -0800449 * pointer arithmetic, so we can perform this to_vmem_altmap()
450 * conversion without concern for the initialization state of
451 * the struct page fields.
452 */
453 struct page *page = (struct page *) memmap_start;
454 struct dev_pagemap *pgmap;
455
456 /*
Andreas Ziegler07061aa2016-03-15 14:55:33 -0700457 * Unconditionally retrieve a dev_pagemap associated with the
Dan Williams4b94ffd2016-01-15 16:56:22 -0800458 * given physical address, this is only for use in the
459 * arch_{add|remove}_memory() for setting up and tearing down
460 * the memmap.
461 */
462 rcu_read_lock();
463 pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page)));
464 rcu_read_unlock();
465
466 return pgmap ? pgmap->altmap : NULL;
467}
Christoph Hellwig41e94a82015-08-17 16:00:35 +0200468#endif /* CONFIG_ZONE_DEVICE */