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13#include <linux/radix-tree.h>
14#include <linux/memremap.h>
15#include <linux/device.h>
16#include <linux/types.h>
17#include <linux/pfn_t.h>
18#include <linux/io.h>
19#include <linux/mm.h>
20#include <linux/memory_hotplug.h>
21
22#ifndef ioremap_cache
23
24__weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size)
25{
26 return ioremap(offset, size);
27}
28#endif
29
30static void *try_ram_remap(resource_size_t offset, size_t size)
31{
32 unsigned long pfn = PHYS_PFN(offset);
33
34
35 if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn)))
36 return __va(offset);
37 return NULL;
38}
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67void *memremap(resource_size_t offset, size_t size, unsigned long flags)
68{
69 int is_ram = region_intersects(offset, size,
70 IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
71 void *addr = NULL;
72
73 if (!flags)
74 return NULL;
75
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
83 if (flags & MEMREMAP_WB) {
84
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89
90 if (is_ram == REGION_INTERSECTS)
91 addr = try_ram_remap(offset, size);
92 if (!addr)
93 addr = ioremap_cache(offset, size);
94 }
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101
102 if (!addr && is_ram == REGION_INTERSECTS && flags != MEMREMAP_WB) {
103 WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",
104 &offset, (unsigned long) size);
105 return NULL;
106 }
107
108 if (!addr && (flags & MEMREMAP_WT))
109 addr = ioremap_wt(offset, size);
110
111 if (!addr && (flags & MEMREMAP_WC))
112 addr = ioremap_wc(offset, size);
113
114 return addr;
115}
116EXPORT_SYMBOL(memremap);
117
118void memunmap(void *addr)
119{
120 if (is_vmalloc_addr(addr))
121 iounmap((void __iomem *) addr);
122}
123EXPORT_SYMBOL(memunmap);
124
125static void devm_memremap_release(struct device *dev, void *res)
126{
127 memunmap(*(void **)res);
128}
129
130static int devm_memremap_match(struct device *dev, void *res, void *match_data)
131{
132 return *(void **)res == match_data;
133}
134
135void *devm_memremap(struct device *dev, resource_size_t offset,
136 size_t size, unsigned long flags)
137{
138 void **ptr, *addr;
139
140 ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL,
141 dev_to_node(dev));
142 if (!ptr)
143 return ERR_PTR(-ENOMEM);
144
145 addr = memremap(offset, size, flags);
146 if (addr) {
147 *ptr = addr;
148 devres_add(dev, ptr);
149 } else {
150 devres_free(ptr);
151 return ERR_PTR(-ENXIO);
152 }
153
154 return addr;
155}
156EXPORT_SYMBOL(devm_memremap);
157
158void devm_memunmap(struct device *dev, void *addr)
159{
160 WARN_ON(devres_release(dev, devm_memremap_release,
161 devm_memremap_match, addr));
162}
163EXPORT_SYMBOL(devm_memunmap);
164
165pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags)
166{
167 return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags);
168}
169EXPORT_SYMBOL(phys_to_pfn_t);
170
171#ifdef CONFIG_ZONE_DEVICE
172static DEFINE_MUTEX(pgmap_lock);
173static RADIX_TREE(pgmap_radix, GFP_KERNEL);
174#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)
175#define SECTION_SIZE (1UL << PA_SECTION_SHIFT)
176
177struct page_map {
178 struct resource res;
179 struct percpu_ref *ref;
180 struct dev_pagemap pgmap;
181 struct vmem_altmap altmap;
182};
183
184void get_zone_device_page(struct page *page)
185{
186 percpu_ref_get(page->pgmap->ref);
187}
188EXPORT_SYMBOL(get_zone_device_page);
189
190void put_zone_device_page(struct page *page)
191{
192 put_dev_pagemap(page->pgmap);
193}
194EXPORT_SYMBOL(put_zone_device_page);
195
196static void pgmap_radix_release(struct resource *res)
197{
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;
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
210static 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
223static 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
233static void devm_memremap_pages_release(struct device *dev, void *data)
234{
235 struct page_map *page_map = data;
236 struct resource *res = &page_map->res;
237 resource_size_t align_start, align_size;
238 struct dev_pagemap *pgmap = &page_map->pgmap;
239
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
245
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);
249 pgmap_radix_release(res);
250 dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc,
251 "%s: failed to free all reserved pages\n", __func__);
252}
253
254
255struct 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;
263}
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280void *devm_memremap_pages(struct device *dev, struct resource *res,
281 struct percpu_ref *ref, struct vmem_altmap *altmap)
282{
283 resource_size_t key, align_start, align_size, align_end;
284 struct dev_pagemap *pgmap;
285 struct page_map *page_map;
286 int error, nid, is_ram;
287 unsigned long pfn;
288
289 align_start = res->start & ~(SECTION_SIZE - 1);
290 align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
291 - align_start;
292 is_ram = region_intersects(align_start, align_size,
293 IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
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
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
310 if (!ref)
311 return ERR_PTR(-EINVAL);
312
313 page_map = devres_alloc_node(devm_memremap_pages_release,
314 sizeof(*page_map), GFP_KERNEL, dev_to_node(dev));
315 if (!page_map)
316 return ERR_PTR(-ENOMEM);
317 pgmap = &page_map->pgmap;
318
319 memcpy(&page_map->res, res, sizeof(*res));
320
321 pgmap->dev = dev;
322 if (altmap) {
323 memcpy(&page_map->altmap, altmap, sizeof(*altmap));
324 pgmap->altmap = &page_map->altmap;
325 }
326 pgmap->ref = ref;
327 pgmap->res = &page_map->res;
328
329 mutex_lock(&pgmap_lock);
330 error = 0;
331 align_end = align_start + align_size - 1;
332 for (key = align_start; key <= align_end; key += SECTION_SIZE) {
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
355 nid = dev_to_node(dev);
356 if (nid < 0)
357 nid = numa_mem_id();
358
359 error = arch_add_memory(nid, align_start, align_size, true);
360 if (error)
361 goto err_add_memory;
362
363 for_each_device_pfn(pfn, page_map) {
364 struct page *page = pfn_to_page(pfn);
365
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371
372 list_del(&page->lru);
373 page->pgmap = pgmap;
374 }
375 devres_add(dev, page_map);
376 return __va(res->start);
377
378 err_add_memory:
379 err_radix:
380 pgmap_radix_release(res);
381 devres_free(page_map);
382 return ERR_PTR(error);
383}
384EXPORT_SYMBOL(devm_memremap_pages);
385
386unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
387{
388
389 return altmap->reserve + altmap->free;
390}
391
392void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns)
393{
394 altmap->alloc -= nr_pfns;
395}
396
397#ifdef CONFIG_SPARSEMEM_VMEMMAP
398struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
399{
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408 struct page *page = (struct page *) memmap_start;
409 struct dev_pagemap *pgmap;
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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
424#endif
425