]>
Commit | Line | Data |
---|---|---|
55716d26 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9f645532 TH |
2 | /* |
3 | * mm/percpu-vm.c - vmalloc area based chunk allocation | |
4 | * | |
5 | * Copyright (C) 2010 SUSE Linux Products GmbH | |
6 | * Copyright (C) 2010 Tejun Heo <tj@kernel.org> | |
7 | * | |
9f645532 TH |
8 | * Chunks are mapped into vmalloc areas and populated page by page. |
9 | * This is the default chunk allocator. | |
10 | */ | |
11 | ||
12 | static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk, | |
13 | unsigned int cpu, int page_idx) | |
14 | { | |
15 | /* must not be used on pre-mapped chunk */ | |
16 | WARN_ON(chunk->immutable); | |
17 | ||
18 | return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx)); | |
19 | } | |
20 | ||
21 | /** | |
fbbb7f4e | 22 | * pcpu_get_pages - get temp pages array |
9f645532 | 23 | * |
fbbb7f4e | 24 | * Returns pointer to array of pointers to struct page which can be indexed |
cdb4cba5 TH |
25 | * with pcpu_page_idx(). Note that there is only one array and accesses |
26 | * should be serialized by pcpu_alloc_mutex. | |
9f645532 TH |
27 | * |
28 | * RETURNS: | |
fbbb7f4e | 29 | * Pointer to temp pages array on success. |
9f645532 | 30 | */ |
8a1df543 | 31 | static struct page **pcpu_get_pages(void) |
9f645532 TH |
32 | { |
33 | static struct page **pages; | |
9f645532 | 34 | size_t pages_size = pcpu_nr_units * pcpu_unit_pages * sizeof(pages[0]); |
9f645532 | 35 | |
cdb4cba5 TH |
36 | lockdep_assert_held(&pcpu_alloc_mutex); |
37 | ||
38 | if (!pages) | |
554fef1c | 39 | pages = pcpu_mem_zalloc(pages_size, GFP_KERNEL); |
9f645532 TH |
40 | return pages; |
41 | } | |
42 | ||
43 | /** | |
44 | * pcpu_free_pages - free pages which were allocated for @chunk | |
45 | * @chunk: chunk pages were allocated for | |
46 | * @pages: array of pages to be freed, indexed by pcpu_page_idx() | |
9f645532 TH |
47 | * @page_start: page index of the first page to be freed |
48 | * @page_end: page index of the last page to be freed + 1 | |
49 | * | |
50 | * Free pages [@page_start and @page_end) in @pages for all units. | |
51 | * The pages were allocated for @chunk. | |
52 | */ | |
53 | static void pcpu_free_pages(struct pcpu_chunk *chunk, | |
fbbb7f4e | 54 | struct page **pages, int page_start, int page_end) |
9f645532 TH |
55 | { |
56 | unsigned int cpu; | |
57 | int i; | |
58 | ||
59 | for_each_possible_cpu(cpu) { | |
60 | for (i = page_start; i < page_end; i++) { | |
61 | struct page *page = pages[pcpu_page_idx(cpu, i)]; | |
62 | ||
63 | if (page) | |
64 | __free_page(page); | |
65 | } | |
66 | } | |
67 | } | |
68 | ||
69 | /** | |
70 | * pcpu_alloc_pages - allocates pages for @chunk | |
71 | * @chunk: target chunk | |
72 | * @pages: array to put the allocated pages into, indexed by pcpu_page_idx() | |
9f645532 TH |
73 | * @page_start: page index of the first page to be allocated |
74 | * @page_end: page index of the last page to be allocated + 1 | |
47504ee0 | 75 | * @gfp: allocation flags passed to the underlying allocator |
9f645532 TH |
76 | * |
77 | * Allocate pages [@page_start,@page_end) into @pages for all units. | |
78 | * The allocation is for @chunk. Percpu core doesn't care about the | |
79 | * content of @pages and will pass it verbatim to pcpu_map_pages(). | |
80 | */ | |
81 | static int pcpu_alloc_pages(struct pcpu_chunk *chunk, | |
47504ee0 DZ |
82 | struct page **pages, int page_start, int page_end, |
83 | gfp_t gfp) | |
9f645532 | 84 | { |
f0d27965 | 85 | unsigned int cpu, tcpu; |
9f645532 TH |
86 | int i; |
87 | ||
554fef1c | 88 | gfp |= __GFP_HIGHMEM; |
47504ee0 | 89 | |
9f645532 TH |
90 | for_each_possible_cpu(cpu) { |
91 | for (i = page_start; i < page_end; i++) { | |
92 | struct page **pagep = &pages[pcpu_page_idx(cpu, i)]; | |
93 | ||
94 | *pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0); | |
f0d27965 TH |
95 | if (!*pagep) |
96 | goto err; | |
9f645532 TH |
97 | } |
98 | } | |
99 | return 0; | |
f0d27965 TH |
100 | |
101 | err: | |
102 | while (--i >= page_start) | |
103 | __free_page(pages[pcpu_page_idx(cpu, i)]); | |
104 | ||
105 | for_each_possible_cpu(tcpu) { | |
106 | if (tcpu == cpu) | |
107 | break; | |
108 | for (i = page_start; i < page_end; i++) | |
109 | __free_page(pages[pcpu_page_idx(tcpu, i)]); | |
110 | } | |
111 | return -ENOMEM; | |
9f645532 TH |
112 | } |
113 | ||
114 | /** | |
115 | * pcpu_pre_unmap_flush - flush cache prior to unmapping | |
116 | * @chunk: chunk the regions to be flushed belongs to | |
117 | * @page_start: page index of the first page to be flushed | |
118 | * @page_end: page index of the last page to be flushed + 1 | |
119 | * | |
120 | * Pages in [@page_start,@page_end) of @chunk are about to be | |
121 | * unmapped. Flush cache. As each flushing trial can be very | |
122 | * expensive, issue flush on the whole region at once rather than | |
123 | * doing it for each cpu. This could be an overkill but is more | |
124 | * scalable. | |
125 | */ | |
126 | static void pcpu_pre_unmap_flush(struct pcpu_chunk *chunk, | |
127 | int page_start, int page_end) | |
128 | { | |
129 | flush_cache_vunmap( | |
a855b84c TH |
130 | pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start), |
131 | pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end)); | |
9f645532 TH |
132 | } |
133 | ||
134 | static void __pcpu_unmap_pages(unsigned long addr, int nr_pages) | |
135 | { | |
136 | unmap_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT); | |
137 | } | |
138 | ||
139 | /** | |
140 | * pcpu_unmap_pages - unmap pages out of a pcpu_chunk | |
141 | * @chunk: chunk of interest | |
142 | * @pages: pages array which can be used to pass information to free | |
9f645532 TH |
143 | * @page_start: page index of the first page to unmap |
144 | * @page_end: page index of the last page to unmap + 1 | |
145 | * | |
146 | * For each cpu, unmap pages [@page_start,@page_end) out of @chunk. | |
147 | * Corresponding elements in @pages were cleared by the caller and can | |
148 | * be used to carry information to pcpu_free_pages() which will be | |
149 | * called after all unmaps are finished. The caller should call | |
150 | * proper pre/post flush functions. | |
151 | */ | |
152 | static void pcpu_unmap_pages(struct pcpu_chunk *chunk, | |
fbbb7f4e | 153 | struct page **pages, int page_start, int page_end) |
9f645532 TH |
154 | { |
155 | unsigned int cpu; | |
156 | int i; | |
157 | ||
158 | for_each_possible_cpu(cpu) { | |
159 | for (i = page_start; i < page_end; i++) { | |
160 | struct page *page; | |
161 | ||
162 | page = pcpu_chunk_page(chunk, cpu, i); | |
163 | WARN_ON(!page); | |
164 | pages[pcpu_page_idx(cpu, i)] = page; | |
165 | } | |
166 | __pcpu_unmap_pages(pcpu_chunk_addr(chunk, cpu, page_start), | |
167 | page_end - page_start); | |
168 | } | |
9f645532 TH |
169 | } |
170 | ||
171 | /** | |
172 | * pcpu_post_unmap_tlb_flush - flush TLB after unmapping | |
173 | * @chunk: pcpu_chunk the regions to be flushed belong to | |
174 | * @page_start: page index of the first page to be flushed | |
175 | * @page_end: page index of the last page to be flushed + 1 | |
176 | * | |
177 | * Pages [@page_start,@page_end) of @chunk have been unmapped. Flush | |
178 | * TLB for the regions. This can be skipped if the area is to be | |
179 | * returned to vmalloc as vmalloc will handle TLB flushing lazily. | |
180 | * | |
181 | * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once | |
182 | * for the whole region. | |
183 | */ | |
184 | static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk, | |
185 | int page_start, int page_end) | |
186 | { | |
187 | flush_tlb_kernel_range( | |
a855b84c TH |
188 | pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start), |
189 | pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end)); | |
9f645532 TH |
190 | } |
191 | ||
192 | static int __pcpu_map_pages(unsigned long addr, struct page **pages, | |
193 | int nr_pages) | |
194 | { | |
195 | return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT, | |
196 | PAGE_KERNEL, pages); | |
197 | } | |
198 | ||
199 | /** | |
200 | * pcpu_map_pages - map pages into a pcpu_chunk | |
201 | * @chunk: chunk of interest | |
202 | * @pages: pages array containing pages to be mapped | |
9f645532 TH |
203 | * @page_start: page index of the first page to map |
204 | * @page_end: page index of the last page to map + 1 | |
205 | * | |
206 | * For each cpu, map pages [@page_start,@page_end) into @chunk. The | |
207 | * caller is responsible for calling pcpu_post_map_flush() after all | |
208 | * mappings are complete. | |
209 | * | |
fbbb7f4e TH |
210 | * This function is responsible for setting up whatever is necessary for |
211 | * reverse lookup (addr -> chunk). | |
9f645532 TH |
212 | */ |
213 | static int pcpu_map_pages(struct pcpu_chunk *chunk, | |
fbbb7f4e | 214 | struct page **pages, int page_start, int page_end) |
9f645532 TH |
215 | { |
216 | unsigned int cpu, tcpu; | |
217 | int i, err; | |
218 | ||
219 | for_each_possible_cpu(cpu) { | |
220 | err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start), | |
221 | &pages[pcpu_page_idx(cpu, page_start)], | |
222 | page_end - page_start); | |
223 | if (err < 0) | |
224 | goto err; | |
9f645532 | 225 | |
fbbb7f4e | 226 | for (i = page_start; i < page_end; i++) |
9f645532 TH |
227 | pcpu_set_page_chunk(pages[pcpu_page_idx(cpu, i)], |
228 | chunk); | |
9f645532 | 229 | } |
9f645532 | 230 | return 0; |
9f645532 TH |
231 | err: |
232 | for_each_possible_cpu(tcpu) { | |
233 | if (tcpu == cpu) | |
234 | break; | |
235 | __pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start), | |
236 | page_end - page_start); | |
237 | } | |
849f5169 | 238 | pcpu_post_unmap_tlb_flush(chunk, page_start, page_end); |
9f645532 TH |
239 | return err; |
240 | } | |
241 | ||
242 | /** | |
243 | * pcpu_post_map_flush - flush cache after mapping | |
244 | * @chunk: pcpu_chunk the regions to be flushed belong to | |
245 | * @page_start: page index of the first page to be flushed | |
246 | * @page_end: page index of the last page to be flushed + 1 | |
247 | * | |
248 | * Pages [@page_start,@page_end) of @chunk have been mapped. Flush | |
249 | * cache. | |
250 | * | |
251 | * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once | |
252 | * for the whole region. | |
253 | */ | |
254 | static void pcpu_post_map_flush(struct pcpu_chunk *chunk, | |
255 | int page_start, int page_end) | |
256 | { | |
257 | flush_cache_vmap( | |
a855b84c TH |
258 | pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start), |
259 | pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end)); | |
9f645532 TH |
260 | } |
261 | ||
262 | /** | |
263 | * pcpu_populate_chunk - populate and map an area of a pcpu_chunk | |
264 | * @chunk: chunk of interest | |
a93ace48 TH |
265 | * @page_start: the start page |
266 | * @page_end: the end page | |
47504ee0 | 267 | * @gfp: allocation flags passed to the underlying memory allocator |
9f645532 TH |
268 | * |
269 | * For each cpu, populate and map pages [@page_start,@page_end) into | |
dca49645 | 270 | * @chunk. |
9f645532 TH |
271 | * |
272 | * CONTEXT: | |
273 | * pcpu_alloc_mutex, does GFP_KERNEL allocation. | |
274 | */ | |
a93ace48 | 275 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, |
47504ee0 | 276 | int page_start, int page_end, gfp_t gfp) |
9f645532 | 277 | { |
9f645532 | 278 | struct page **pages; |
9f645532 | 279 | |
8a1df543 | 280 | pages = pcpu_get_pages(); |
9f645532 TH |
281 | if (!pages) |
282 | return -ENOMEM; | |
283 | ||
47504ee0 | 284 | if (pcpu_alloc_pages(chunk, pages, page_start, page_end, gfp)) |
a93ace48 | 285 | return -ENOMEM; |
9f645532 | 286 | |
a93ace48 TH |
287 | if (pcpu_map_pages(chunk, pages, page_start, page_end)) { |
288 | pcpu_free_pages(chunk, pages, page_start, page_end); | |
289 | return -ENOMEM; | |
9f645532 TH |
290 | } |
291 | pcpu_post_map_flush(chunk, page_start, page_end); | |
292 | ||
9f645532 | 293 | return 0; |
9f645532 TH |
294 | } |
295 | ||
296 | /** | |
297 | * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk | |
298 | * @chunk: chunk to depopulate | |
a93ace48 TH |
299 | * @page_start: the start page |
300 | * @page_end: the end page | |
9f645532 TH |
301 | * |
302 | * For each cpu, depopulate and unmap pages [@page_start,@page_end) | |
a93ace48 | 303 | * from @chunk. |
9f645532 TH |
304 | * |
305 | * CONTEXT: | |
306 | * pcpu_alloc_mutex. | |
307 | */ | |
a93ace48 TH |
308 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, |
309 | int page_start, int page_end) | |
9f645532 | 310 | { |
9f645532 | 311 | struct page **pages; |
9f645532 | 312 | |
9f645532 TH |
313 | /* |
314 | * If control reaches here, there must have been at least one | |
315 | * successful population attempt so the temp pages array must | |
316 | * be available now. | |
317 | */ | |
8a1df543 | 318 | pages = pcpu_get_pages(); |
9f645532 TH |
319 | BUG_ON(!pages); |
320 | ||
321 | /* unmap and free */ | |
322 | pcpu_pre_unmap_flush(chunk, page_start, page_end); | |
323 | ||
a93ace48 | 324 | pcpu_unmap_pages(chunk, pages, page_start, page_end); |
9f645532 TH |
325 | |
326 | /* no need to flush tlb, vmalloc will handle it lazily */ | |
327 | ||
a93ace48 | 328 | pcpu_free_pages(chunk, pages, page_start, page_end); |
9f645532 TH |
329 | } |
330 | ||
47504ee0 | 331 | static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp) |
9f645532 TH |
332 | { |
333 | struct pcpu_chunk *chunk; | |
334 | struct vm_struct **vms; | |
335 | ||
47504ee0 | 336 | chunk = pcpu_alloc_chunk(gfp); |
9f645532 TH |
337 | if (!chunk) |
338 | return NULL; | |
339 | ||
340 | vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes, | |
ec3f64fc | 341 | pcpu_nr_groups, pcpu_atom_size); |
9f645532 TH |
342 | if (!vms) { |
343 | pcpu_free_chunk(chunk); | |
344 | return NULL; | |
345 | } | |
346 | ||
347 | chunk->data = vms; | |
348 | chunk->base_addr = vms[0]->addr - pcpu_group_offsets[0]; | |
30a5b536 DZ |
349 | |
350 | pcpu_stats_chunk_alloc(); | |
df95e795 | 351 | trace_percpu_create_chunk(chunk->base_addr); |
30a5b536 | 352 | |
9f645532 TH |
353 | return chunk; |
354 | } | |
355 | ||
356 | static void pcpu_destroy_chunk(struct pcpu_chunk *chunk) | |
357 | { | |
e3efe3db DZ |
358 | if (!chunk) |
359 | return; | |
360 | ||
30a5b536 | 361 | pcpu_stats_chunk_dealloc(); |
df95e795 | 362 | trace_percpu_destroy_chunk(chunk->base_addr); |
30a5b536 | 363 | |
e3efe3db | 364 | if (chunk->data) |
9f645532 TH |
365 | pcpu_free_vm_areas(chunk->data, pcpu_nr_groups); |
366 | pcpu_free_chunk(chunk); | |
367 | } | |
368 | ||
369 | static struct page *pcpu_addr_to_page(void *addr) | |
370 | { | |
371 | return vmalloc_to_page(addr); | |
372 | } | |
373 | ||
374 | static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai) | |
375 | { | |
376 | /* no extra restriction */ | |
377 | return 0; | |
378 | } |