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fbf59bc9 TH |
1 | /* |
2 | * linux/mm/percpu.c - percpu memory allocator | |
3 | * | |
4 | * Copyright (C) 2009 SUSE Linux Products GmbH | |
5 | * Copyright (C) 2009 Tejun Heo <tj@kernel.org> | |
6 | * | |
7 | * This file is released under the GPLv2. | |
8 | * | |
9 | * This is percpu allocator which can handle both static and dynamic | |
10 | * areas. Percpu areas are allocated in chunks in vmalloc area. Each | |
2f39e637 TH |
11 | * chunk is consisted of boot-time determined number of units and the |
12 | * first chunk is used for static percpu variables in the kernel image | |
13 | * (special boot time alloc/init handling necessary as these areas | |
14 | * need to be brought up before allocation services are running). | |
15 | * Unit grows as necessary and all units grow or shrink in unison. | |
16 | * When a chunk is filled up, another chunk is allocated. ie. in | |
17 | * vmalloc area | |
fbf59bc9 TH |
18 | * |
19 | * c0 c1 c2 | |
20 | * ------------------- ------------------- ------------ | |
21 | * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u | |
22 | * ------------------- ...... ------------------- .... ------------ | |
23 | * | |
24 | * Allocation is done in offset-size areas of single unit space. Ie, | |
25 | * an area of 512 bytes at 6k in c1 occupies 512 bytes at 6k of c1:u0, | |
2f39e637 TH |
26 | * c1:u1, c1:u2 and c1:u3. On UMA, units corresponds directly to |
27 | * cpus. On NUMA, the mapping can be non-linear and even sparse. | |
28 | * Percpu access can be done by configuring percpu base registers | |
29 | * according to cpu to unit mapping and pcpu_unit_size. | |
fbf59bc9 | 30 | * |
2f39e637 TH |
31 | * There are usually many small percpu allocations many of them being |
32 | * as small as 4 bytes. The allocator organizes chunks into lists | |
fbf59bc9 TH |
33 | * according to free size and tries to allocate from the fullest one. |
34 | * Each chunk keeps the maximum contiguous area size hint which is | |
35 | * guaranteed to be eqaul to or larger than the maximum contiguous | |
36 | * area in the chunk. This helps the allocator not to iterate the | |
37 | * chunk maps unnecessarily. | |
38 | * | |
39 | * Allocation state in each chunk is kept using an array of integers | |
40 | * on chunk->map. A positive value in the map represents a free | |
41 | * region and negative allocated. Allocation inside a chunk is done | |
42 | * by scanning this map sequentially and serving the first matching | |
43 | * entry. This is mostly copied from the percpu_modalloc() allocator. | |
e1b9aa3f CL |
44 | * Chunks can be determined from the address using the index field |
45 | * in the page struct. The index field contains a pointer to the chunk. | |
fbf59bc9 TH |
46 | * |
47 | * To use this allocator, arch code should do the followings. | |
48 | * | |
e74e3962 | 49 | * - drop CONFIG_HAVE_LEGACY_PER_CPU_AREA |
fbf59bc9 TH |
50 | * |
51 | * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate | |
e0100983 TH |
52 | * regular address to percpu pointer and back if they need to be |
53 | * different from the default | |
fbf59bc9 | 54 | * |
8d408b4b TH |
55 | * - use pcpu_setup_first_chunk() during percpu area initialization to |
56 | * setup the first chunk containing the kernel static percpu area | |
fbf59bc9 TH |
57 | */ |
58 | ||
59 | #include <linux/bitmap.h> | |
60 | #include <linux/bootmem.h> | |
fd1e8a1f | 61 | #include <linux/err.h> |
fbf59bc9 | 62 | #include <linux/list.h> |
a530b795 | 63 | #include <linux/log2.h> |
fbf59bc9 TH |
64 | #include <linux/mm.h> |
65 | #include <linux/module.h> | |
66 | #include <linux/mutex.h> | |
67 | #include <linux/percpu.h> | |
68 | #include <linux/pfn.h> | |
fbf59bc9 | 69 | #include <linux/slab.h> |
ccea34b5 | 70 | #include <linux/spinlock.h> |
fbf59bc9 | 71 | #include <linux/vmalloc.h> |
a56dbddf | 72 | #include <linux/workqueue.h> |
fbf59bc9 TH |
73 | |
74 | #include <asm/cacheflush.h> | |
e0100983 | 75 | #include <asm/sections.h> |
fbf59bc9 TH |
76 | #include <asm/tlbflush.h> |
77 | ||
fbf59bc9 TH |
78 | #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ |
79 | #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ | |
80 | ||
e0100983 TH |
81 | /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ |
82 | #ifndef __addr_to_pcpu_ptr | |
83 | #define __addr_to_pcpu_ptr(addr) \ | |
84 | (void *)((unsigned long)(addr) - (unsigned long)pcpu_base_addr \ | |
85 | + (unsigned long)__per_cpu_start) | |
86 | #endif | |
87 | #ifndef __pcpu_ptr_to_addr | |
88 | #define __pcpu_ptr_to_addr(ptr) \ | |
89 | (void *)((unsigned long)(ptr) + (unsigned long)pcpu_base_addr \ | |
90 | - (unsigned long)__per_cpu_start) | |
91 | #endif | |
92 | ||
fbf59bc9 TH |
93 | struct pcpu_chunk { |
94 | struct list_head list; /* linked to pcpu_slot lists */ | |
fbf59bc9 TH |
95 | int free_size; /* free bytes in the chunk */ |
96 | int contig_hint; /* max contiguous size hint */ | |
bba174f5 | 97 | void *base_addr; /* base address of this chunk */ |
fbf59bc9 TH |
98 | int map_used; /* # of map entries used */ |
99 | int map_alloc; /* # of map entries allocated */ | |
100 | int *map; /* allocation map */ | |
6563297c | 101 | struct vm_struct **vms; /* mapped vmalloc regions */ |
8d408b4b | 102 | bool immutable; /* no [de]population allowed */ |
ce3141a2 | 103 | unsigned long populated[]; /* populated bitmap */ |
fbf59bc9 TH |
104 | }; |
105 | ||
40150d37 TH |
106 | static int pcpu_unit_pages __read_mostly; |
107 | static int pcpu_unit_size __read_mostly; | |
2f39e637 | 108 | static int pcpu_nr_units __read_mostly; |
6563297c | 109 | static int pcpu_atom_size __read_mostly; |
40150d37 TH |
110 | static int pcpu_nr_slots __read_mostly; |
111 | static size_t pcpu_chunk_struct_size __read_mostly; | |
fbf59bc9 | 112 | |
2f39e637 TH |
113 | /* cpus with the lowest and highest unit numbers */ |
114 | static unsigned int pcpu_first_unit_cpu __read_mostly; | |
115 | static unsigned int pcpu_last_unit_cpu __read_mostly; | |
116 | ||
fbf59bc9 | 117 | /* the address of the first chunk which starts with the kernel static area */ |
40150d37 | 118 | void *pcpu_base_addr __read_mostly; |
fbf59bc9 TH |
119 | EXPORT_SYMBOL_GPL(pcpu_base_addr); |
120 | ||
fb435d52 TH |
121 | static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */ |
122 | const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */ | |
2f39e637 | 123 | |
6563297c TH |
124 | /* group information, used for vm allocation */ |
125 | static int pcpu_nr_groups __read_mostly; | |
126 | static const unsigned long *pcpu_group_offsets __read_mostly; | |
127 | static const size_t *pcpu_group_sizes __read_mostly; | |
128 | ||
ae9e6bc9 TH |
129 | /* |
130 | * The first chunk which always exists. Note that unlike other | |
131 | * chunks, this one can be allocated and mapped in several different | |
132 | * ways and thus often doesn't live in the vmalloc area. | |
133 | */ | |
134 | static struct pcpu_chunk *pcpu_first_chunk; | |
135 | ||
136 | /* | |
137 | * Optional reserved chunk. This chunk reserves part of the first | |
138 | * chunk and serves it for reserved allocations. The amount of | |
139 | * reserved offset is in pcpu_reserved_chunk_limit. When reserved | |
140 | * area doesn't exist, the following variables contain NULL and 0 | |
141 | * respectively. | |
142 | */ | |
edcb4639 | 143 | static struct pcpu_chunk *pcpu_reserved_chunk; |
edcb4639 TH |
144 | static int pcpu_reserved_chunk_limit; |
145 | ||
fbf59bc9 | 146 | /* |
ccea34b5 TH |
147 | * Synchronization rules. |
148 | * | |
149 | * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former | |
ce3141a2 TH |
150 | * protects allocation/reclaim paths, chunks, populated bitmap and |
151 | * vmalloc mapping. The latter is a spinlock and protects the index | |
152 | * data structures - chunk slots, chunks and area maps in chunks. | |
ccea34b5 TH |
153 | * |
154 | * During allocation, pcpu_alloc_mutex is kept locked all the time and | |
155 | * pcpu_lock is grabbed and released as necessary. All actual memory | |
403a91b1 JK |
156 | * allocations are done using GFP_KERNEL with pcpu_lock released. In |
157 | * general, percpu memory can't be allocated with irq off but | |
158 | * irqsave/restore are still used in alloc path so that it can be used | |
159 | * from early init path - sched_init() specifically. | |
ccea34b5 TH |
160 | * |
161 | * Free path accesses and alters only the index data structures, so it | |
162 | * can be safely called from atomic context. When memory needs to be | |
163 | * returned to the system, free path schedules reclaim_work which | |
164 | * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be | |
165 | * reclaimed, release both locks and frees the chunks. Note that it's | |
166 | * necessary to grab both locks to remove a chunk from circulation as | |
167 | * allocation path might be referencing the chunk with only | |
168 | * pcpu_alloc_mutex locked. | |
fbf59bc9 | 169 | */ |
ccea34b5 TH |
170 | static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */ |
171 | static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */ | |
fbf59bc9 | 172 | |
40150d37 | 173 | static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ |
fbf59bc9 | 174 | |
a56dbddf TH |
175 | /* reclaim work to release fully free chunks, scheduled from free path */ |
176 | static void pcpu_reclaim(struct work_struct *work); | |
177 | static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); | |
178 | ||
d9b55eeb | 179 | static int __pcpu_size_to_slot(int size) |
fbf59bc9 | 180 | { |
cae3aeb8 | 181 | int highbit = fls(size); /* size is in bytes */ |
fbf59bc9 TH |
182 | return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); |
183 | } | |
184 | ||
d9b55eeb TH |
185 | static int pcpu_size_to_slot(int size) |
186 | { | |
187 | if (size == pcpu_unit_size) | |
188 | return pcpu_nr_slots - 1; | |
189 | return __pcpu_size_to_slot(size); | |
190 | } | |
191 | ||
fbf59bc9 TH |
192 | static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) |
193 | { | |
194 | if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) | |
195 | return 0; | |
196 | ||
197 | return pcpu_size_to_slot(chunk->free_size); | |
198 | } | |
199 | ||
200 | static int pcpu_page_idx(unsigned int cpu, int page_idx) | |
201 | { | |
2f39e637 | 202 | return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; |
fbf59bc9 TH |
203 | } |
204 | ||
205 | static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, | |
206 | unsigned int cpu, int page_idx) | |
207 | { | |
bba174f5 | 208 | return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] + |
fb435d52 | 209 | (page_idx << PAGE_SHIFT); |
fbf59bc9 TH |
210 | } |
211 | ||
ce3141a2 TH |
212 | static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk, |
213 | unsigned int cpu, int page_idx) | |
fbf59bc9 | 214 | { |
ce3141a2 TH |
215 | /* must not be used on pre-mapped chunk */ |
216 | WARN_ON(chunk->immutable); | |
c8a51be4 | 217 | |
ce3141a2 | 218 | return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx)); |
fbf59bc9 TH |
219 | } |
220 | ||
e1b9aa3f CL |
221 | /* set the pointer to a chunk in a page struct */ |
222 | static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) | |
223 | { | |
224 | page->index = (unsigned long)pcpu; | |
225 | } | |
226 | ||
227 | /* obtain pointer to a chunk from a page struct */ | |
228 | static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) | |
229 | { | |
230 | return (struct pcpu_chunk *)page->index; | |
231 | } | |
232 | ||
ce3141a2 TH |
233 | static void pcpu_next_unpop(struct pcpu_chunk *chunk, int *rs, int *re, int end) |
234 | { | |
235 | *rs = find_next_zero_bit(chunk->populated, end, *rs); | |
236 | *re = find_next_bit(chunk->populated, end, *rs + 1); | |
237 | } | |
238 | ||
239 | static void pcpu_next_pop(struct pcpu_chunk *chunk, int *rs, int *re, int end) | |
240 | { | |
241 | *rs = find_next_bit(chunk->populated, end, *rs); | |
242 | *re = find_next_zero_bit(chunk->populated, end, *rs + 1); | |
243 | } | |
244 | ||
245 | /* | |
246 | * (Un)populated page region iterators. Iterate over (un)populated | |
247 | * page regions betwen @start and @end in @chunk. @rs and @re should | |
248 | * be integer variables and will be set to start and end page index of | |
249 | * the current region. | |
250 | */ | |
251 | #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ | |
252 | for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ | |
253 | (rs) < (re); \ | |
254 | (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) | |
255 | ||
256 | #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ | |
257 | for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ | |
258 | (rs) < (re); \ | |
259 | (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) | |
260 | ||
fbf59bc9 | 261 | /** |
1880d93b TH |
262 | * pcpu_mem_alloc - allocate memory |
263 | * @size: bytes to allocate | |
fbf59bc9 | 264 | * |
1880d93b TH |
265 | * Allocate @size bytes. If @size is smaller than PAGE_SIZE, |
266 | * kzalloc() is used; otherwise, vmalloc() is used. The returned | |
267 | * memory is always zeroed. | |
fbf59bc9 | 268 | * |
ccea34b5 TH |
269 | * CONTEXT: |
270 | * Does GFP_KERNEL allocation. | |
271 | * | |
fbf59bc9 | 272 | * RETURNS: |
1880d93b | 273 | * Pointer to the allocated area on success, NULL on failure. |
fbf59bc9 | 274 | */ |
1880d93b | 275 | static void *pcpu_mem_alloc(size_t size) |
fbf59bc9 | 276 | { |
1880d93b TH |
277 | if (size <= PAGE_SIZE) |
278 | return kzalloc(size, GFP_KERNEL); | |
279 | else { | |
280 | void *ptr = vmalloc(size); | |
281 | if (ptr) | |
282 | memset(ptr, 0, size); | |
283 | return ptr; | |
284 | } | |
285 | } | |
fbf59bc9 | 286 | |
1880d93b TH |
287 | /** |
288 | * pcpu_mem_free - free memory | |
289 | * @ptr: memory to free | |
290 | * @size: size of the area | |
291 | * | |
292 | * Free @ptr. @ptr should have been allocated using pcpu_mem_alloc(). | |
293 | */ | |
294 | static void pcpu_mem_free(void *ptr, size_t size) | |
295 | { | |
fbf59bc9 | 296 | if (size <= PAGE_SIZE) |
1880d93b | 297 | kfree(ptr); |
fbf59bc9 | 298 | else |
1880d93b | 299 | vfree(ptr); |
fbf59bc9 TH |
300 | } |
301 | ||
302 | /** | |
303 | * pcpu_chunk_relocate - put chunk in the appropriate chunk slot | |
304 | * @chunk: chunk of interest | |
305 | * @oslot: the previous slot it was on | |
306 | * | |
307 | * This function is called after an allocation or free changed @chunk. | |
308 | * New slot according to the changed state is determined and @chunk is | |
edcb4639 TH |
309 | * moved to the slot. Note that the reserved chunk is never put on |
310 | * chunk slots. | |
ccea34b5 TH |
311 | * |
312 | * CONTEXT: | |
313 | * pcpu_lock. | |
fbf59bc9 TH |
314 | */ |
315 | static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) | |
316 | { | |
317 | int nslot = pcpu_chunk_slot(chunk); | |
318 | ||
edcb4639 | 319 | if (chunk != pcpu_reserved_chunk && oslot != nslot) { |
fbf59bc9 TH |
320 | if (oslot < nslot) |
321 | list_move(&chunk->list, &pcpu_slot[nslot]); | |
322 | else | |
323 | list_move_tail(&chunk->list, &pcpu_slot[nslot]); | |
324 | } | |
325 | } | |
326 | ||
fbf59bc9 | 327 | /** |
e1b9aa3f CL |
328 | * pcpu_chunk_addr_search - determine chunk containing specified address |
329 | * @addr: address for which the chunk needs to be determined. | |
ccea34b5 | 330 | * |
fbf59bc9 TH |
331 | * RETURNS: |
332 | * The address of the found chunk. | |
333 | */ | |
334 | static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) | |
335 | { | |
bba174f5 | 336 | void *first_start = pcpu_first_chunk->base_addr; |
fbf59bc9 | 337 | |
ae9e6bc9 | 338 | /* is it in the first chunk? */ |
79ba6ac8 | 339 | if (addr >= first_start && addr < first_start + pcpu_unit_size) { |
ae9e6bc9 TH |
340 | /* is it in the reserved area? */ |
341 | if (addr < first_start + pcpu_reserved_chunk_limit) | |
edcb4639 | 342 | return pcpu_reserved_chunk; |
ae9e6bc9 | 343 | return pcpu_first_chunk; |
edcb4639 TH |
344 | } |
345 | ||
04a13c7c TH |
346 | /* |
347 | * The address is relative to unit0 which might be unused and | |
348 | * thus unmapped. Offset the address to the unit space of the | |
349 | * current processor before looking it up in the vmalloc | |
350 | * space. Note that any possible cpu id can be used here, so | |
351 | * there's no need to worry about preemption or cpu hotplug. | |
352 | */ | |
5579fd7e | 353 | addr += pcpu_unit_offsets[raw_smp_processor_id()]; |
e1b9aa3f | 354 | return pcpu_get_page_chunk(vmalloc_to_page(addr)); |
fbf59bc9 TH |
355 | } |
356 | ||
9f7dcf22 | 357 | /** |
833af842 TH |
358 | * pcpu_need_to_extend - determine whether chunk area map needs to be extended |
359 | * @chunk: chunk of interest | |
9f7dcf22 | 360 | * |
833af842 TH |
361 | * Determine whether area map of @chunk needs to be extended to |
362 | * accomodate a new allocation. | |
9f7dcf22 | 363 | * |
ccea34b5 | 364 | * CONTEXT: |
833af842 | 365 | * pcpu_lock. |
ccea34b5 | 366 | * |
9f7dcf22 | 367 | * RETURNS: |
833af842 TH |
368 | * New target map allocation length if extension is necessary, 0 |
369 | * otherwise. | |
9f7dcf22 | 370 | */ |
833af842 | 371 | static int pcpu_need_to_extend(struct pcpu_chunk *chunk) |
9f7dcf22 TH |
372 | { |
373 | int new_alloc; | |
9f7dcf22 | 374 | |
9f7dcf22 TH |
375 | if (chunk->map_alloc >= chunk->map_used + 2) |
376 | return 0; | |
377 | ||
378 | new_alloc = PCPU_DFL_MAP_ALLOC; | |
379 | while (new_alloc < chunk->map_used + 2) | |
380 | new_alloc *= 2; | |
381 | ||
833af842 TH |
382 | return new_alloc; |
383 | } | |
384 | ||
385 | /** | |
386 | * pcpu_extend_area_map - extend area map of a chunk | |
387 | * @chunk: chunk of interest | |
388 | * @new_alloc: new target allocation length of the area map | |
389 | * | |
390 | * Extend area map of @chunk to have @new_alloc entries. | |
391 | * | |
392 | * CONTEXT: | |
393 | * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock. | |
394 | * | |
395 | * RETURNS: | |
396 | * 0 on success, -errno on failure. | |
397 | */ | |
398 | static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) | |
399 | { | |
400 | int *old = NULL, *new = NULL; | |
401 | size_t old_size = 0, new_size = new_alloc * sizeof(new[0]); | |
402 | unsigned long flags; | |
403 | ||
404 | new = pcpu_mem_alloc(new_size); | |
405 | if (!new) | |
9f7dcf22 | 406 | return -ENOMEM; |
ccea34b5 | 407 | |
833af842 TH |
408 | /* acquire pcpu_lock and switch to new area map */ |
409 | spin_lock_irqsave(&pcpu_lock, flags); | |
410 | ||
411 | if (new_alloc <= chunk->map_alloc) | |
412 | goto out_unlock; | |
9f7dcf22 | 413 | |
833af842 TH |
414 | old_size = chunk->map_alloc * sizeof(chunk->map[0]); |
415 | memcpy(new, chunk->map, old_size); | |
9f7dcf22 TH |
416 | |
417 | /* | |
418 | * map_alloc < PCPU_DFL_MAP_ALLOC indicates that the chunk is | |
419 | * one of the first chunks and still using static map. | |
420 | */ | |
421 | if (chunk->map_alloc >= PCPU_DFL_MAP_ALLOC) | |
833af842 | 422 | old = chunk->map; |
9f7dcf22 TH |
423 | |
424 | chunk->map_alloc = new_alloc; | |
425 | chunk->map = new; | |
833af842 TH |
426 | new = NULL; |
427 | ||
428 | out_unlock: | |
429 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
430 | ||
431 | /* | |
432 | * pcpu_mem_free() might end up calling vfree() which uses | |
433 | * IRQ-unsafe lock and thus can't be called under pcpu_lock. | |
434 | */ | |
435 | pcpu_mem_free(old, old_size); | |
436 | pcpu_mem_free(new, new_size); | |
437 | ||
9f7dcf22 TH |
438 | return 0; |
439 | } | |
440 | ||
fbf59bc9 TH |
441 | /** |
442 | * pcpu_split_block - split a map block | |
443 | * @chunk: chunk of interest | |
444 | * @i: index of map block to split | |
cae3aeb8 TH |
445 | * @head: head size in bytes (can be 0) |
446 | * @tail: tail size in bytes (can be 0) | |
fbf59bc9 TH |
447 | * |
448 | * Split the @i'th map block into two or three blocks. If @head is | |
449 | * non-zero, @head bytes block is inserted before block @i moving it | |
450 | * to @i+1 and reducing its size by @head bytes. | |
451 | * | |
452 | * If @tail is non-zero, the target block, which can be @i or @i+1 | |
453 | * depending on @head, is reduced by @tail bytes and @tail byte block | |
454 | * is inserted after the target block. | |
455 | * | |
9f7dcf22 | 456 | * @chunk->map must have enough free slots to accomodate the split. |
ccea34b5 TH |
457 | * |
458 | * CONTEXT: | |
459 | * pcpu_lock. | |
fbf59bc9 | 460 | */ |
9f7dcf22 TH |
461 | static void pcpu_split_block(struct pcpu_chunk *chunk, int i, |
462 | int head, int tail) | |
fbf59bc9 TH |
463 | { |
464 | int nr_extra = !!head + !!tail; | |
1880d93b | 465 | |
9f7dcf22 | 466 | BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra); |
fbf59bc9 | 467 | |
9f7dcf22 | 468 | /* insert new subblocks */ |
fbf59bc9 TH |
469 | memmove(&chunk->map[i + nr_extra], &chunk->map[i], |
470 | sizeof(chunk->map[0]) * (chunk->map_used - i)); | |
471 | chunk->map_used += nr_extra; | |
472 | ||
473 | if (head) { | |
474 | chunk->map[i + 1] = chunk->map[i] - head; | |
475 | chunk->map[i++] = head; | |
476 | } | |
477 | if (tail) { | |
478 | chunk->map[i++] -= tail; | |
479 | chunk->map[i] = tail; | |
480 | } | |
fbf59bc9 TH |
481 | } |
482 | ||
483 | /** | |
484 | * pcpu_alloc_area - allocate area from a pcpu_chunk | |
485 | * @chunk: chunk of interest | |
cae3aeb8 | 486 | * @size: wanted size in bytes |
fbf59bc9 TH |
487 | * @align: wanted align |
488 | * | |
489 | * Try to allocate @size bytes area aligned at @align from @chunk. | |
490 | * Note that this function only allocates the offset. It doesn't | |
491 | * populate or map the area. | |
492 | * | |
9f7dcf22 TH |
493 | * @chunk->map must have at least two free slots. |
494 | * | |
ccea34b5 TH |
495 | * CONTEXT: |
496 | * pcpu_lock. | |
497 | * | |
fbf59bc9 | 498 | * RETURNS: |
9f7dcf22 TH |
499 | * Allocated offset in @chunk on success, -1 if no matching area is |
500 | * found. | |
fbf59bc9 TH |
501 | */ |
502 | static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align) | |
503 | { | |
504 | int oslot = pcpu_chunk_slot(chunk); | |
505 | int max_contig = 0; | |
506 | int i, off; | |
507 | ||
fbf59bc9 TH |
508 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) { |
509 | bool is_last = i + 1 == chunk->map_used; | |
510 | int head, tail; | |
511 | ||
512 | /* extra for alignment requirement */ | |
513 | head = ALIGN(off, align) - off; | |
514 | BUG_ON(i == 0 && head != 0); | |
515 | ||
516 | if (chunk->map[i] < 0) | |
517 | continue; | |
518 | if (chunk->map[i] < head + size) { | |
519 | max_contig = max(chunk->map[i], max_contig); | |
520 | continue; | |
521 | } | |
522 | ||
523 | /* | |
524 | * If head is small or the previous block is free, | |
525 | * merge'em. Note that 'small' is defined as smaller | |
526 | * than sizeof(int), which is very small but isn't too | |
527 | * uncommon for percpu allocations. | |
528 | */ | |
529 | if (head && (head < sizeof(int) || chunk->map[i - 1] > 0)) { | |
530 | if (chunk->map[i - 1] > 0) | |
531 | chunk->map[i - 1] += head; | |
532 | else { | |
533 | chunk->map[i - 1] -= head; | |
534 | chunk->free_size -= head; | |
535 | } | |
536 | chunk->map[i] -= head; | |
537 | off += head; | |
538 | head = 0; | |
539 | } | |
540 | ||
541 | /* if tail is small, just keep it around */ | |
542 | tail = chunk->map[i] - head - size; | |
543 | if (tail < sizeof(int)) | |
544 | tail = 0; | |
545 | ||
546 | /* split if warranted */ | |
547 | if (head || tail) { | |
9f7dcf22 | 548 | pcpu_split_block(chunk, i, head, tail); |
fbf59bc9 TH |
549 | if (head) { |
550 | i++; | |
551 | off += head; | |
552 | max_contig = max(chunk->map[i - 1], max_contig); | |
553 | } | |
554 | if (tail) | |
555 | max_contig = max(chunk->map[i + 1], max_contig); | |
556 | } | |
557 | ||
558 | /* update hint and mark allocated */ | |
559 | if (is_last) | |
560 | chunk->contig_hint = max_contig; /* fully scanned */ | |
561 | else | |
562 | chunk->contig_hint = max(chunk->contig_hint, | |
563 | max_contig); | |
564 | ||
565 | chunk->free_size -= chunk->map[i]; | |
566 | chunk->map[i] = -chunk->map[i]; | |
567 | ||
568 | pcpu_chunk_relocate(chunk, oslot); | |
569 | return off; | |
570 | } | |
571 | ||
572 | chunk->contig_hint = max_contig; /* fully scanned */ | |
573 | pcpu_chunk_relocate(chunk, oslot); | |
574 | ||
9f7dcf22 TH |
575 | /* tell the upper layer that this chunk has no matching area */ |
576 | return -1; | |
fbf59bc9 TH |
577 | } |
578 | ||
579 | /** | |
580 | * pcpu_free_area - free area to a pcpu_chunk | |
581 | * @chunk: chunk of interest | |
582 | * @freeme: offset of area to free | |
583 | * | |
584 | * Free area starting from @freeme to @chunk. Note that this function | |
585 | * only modifies the allocation map. It doesn't depopulate or unmap | |
586 | * the area. | |
ccea34b5 TH |
587 | * |
588 | * CONTEXT: | |
589 | * pcpu_lock. | |
fbf59bc9 TH |
590 | */ |
591 | static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme) | |
592 | { | |
593 | int oslot = pcpu_chunk_slot(chunk); | |
594 | int i, off; | |
595 | ||
596 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) | |
597 | if (off == freeme) | |
598 | break; | |
599 | BUG_ON(off != freeme); | |
600 | BUG_ON(chunk->map[i] > 0); | |
601 | ||
602 | chunk->map[i] = -chunk->map[i]; | |
603 | chunk->free_size += chunk->map[i]; | |
604 | ||
605 | /* merge with previous? */ | |
606 | if (i > 0 && chunk->map[i - 1] >= 0) { | |
607 | chunk->map[i - 1] += chunk->map[i]; | |
608 | chunk->map_used--; | |
609 | memmove(&chunk->map[i], &chunk->map[i + 1], | |
610 | (chunk->map_used - i) * sizeof(chunk->map[0])); | |
611 | i--; | |
612 | } | |
613 | /* merge with next? */ | |
614 | if (i + 1 < chunk->map_used && chunk->map[i + 1] >= 0) { | |
615 | chunk->map[i] += chunk->map[i + 1]; | |
616 | chunk->map_used--; | |
617 | memmove(&chunk->map[i + 1], &chunk->map[i + 2], | |
618 | (chunk->map_used - (i + 1)) * sizeof(chunk->map[0])); | |
619 | } | |
620 | ||
621 | chunk->contig_hint = max(chunk->map[i], chunk->contig_hint); | |
622 | pcpu_chunk_relocate(chunk, oslot); | |
623 | } | |
624 | ||
625 | /** | |
ce3141a2 | 626 | * pcpu_get_pages_and_bitmap - get temp pages array and bitmap |
fbf59bc9 | 627 | * @chunk: chunk of interest |
ce3141a2 TH |
628 | * @bitmapp: output parameter for bitmap |
629 | * @may_alloc: may allocate the array | |
fbf59bc9 | 630 | * |
ce3141a2 TH |
631 | * Returns pointer to array of pointers to struct page and bitmap, |
632 | * both of which can be indexed with pcpu_page_idx(). The returned | |
633 | * array is cleared to zero and *@bitmapp is copied from | |
634 | * @chunk->populated. Note that there is only one array and bitmap | |
635 | * and access exclusion is the caller's responsibility. | |
636 | * | |
637 | * CONTEXT: | |
638 | * pcpu_alloc_mutex and does GFP_KERNEL allocation if @may_alloc. | |
639 | * Otherwise, don't care. | |
640 | * | |
641 | * RETURNS: | |
642 | * Pointer to temp pages array on success, NULL on failure. | |
fbf59bc9 | 643 | */ |
ce3141a2 TH |
644 | static struct page **pcpu_get_pages_and_bitmap(struct pcpu_chunk *chunk, |
645 | unsigned long **bitmapp, | |
646 | bool may_alloc) | |
fbf59bc9 | 647 | { |
ce3141a2 TH |
648 | static struct page **pages; |
649 | static unsigned long *bitmap; | |
2f39e637 | 650 | size_t pages_size = pcpu_nr_units * pcpu_unit_pages * sizeof(pages[0]); |
ce3141a2 TH |
651 | size_t bitmap_size = BITS_TO_LONGS(pcpu_unit_pages) * |
652 | sizeof(unsigned long); | |
653 | ||
654 | if (!pages || !bitmap) { | |
655 | if (may_alloc && !pages) | |
656 | pages = pcpu_mem_alloc(pages_size); | |
657 | if (may_alloc && !bitmap) | |
658 | bitmap = pcpu_mem_alloc(bitmap_size); | |
659 | if (!pages || !bitmap) | |
660 | return NULL; | |
661 | } | |
fbf59bc9 | 662 | |
ce3141a2 TH |
663 | memset(pages, 0, pages_size); |
664 | bitmap_copy(bitmap, chunk->populated, pcpu_unit_pages); | |
8d408b4b | 665 | |
ce3141a2 TH |
666 | *bitmapp = bitmap; |
667 | return pages; | |
668 | } | |
fbf59bc9 | 669 | |
ce3141a2 TH |
670 | /** |
671 | * pcpu_free_pages - free pages which were allocated for @chunk | |
672 | * @chunk: chunk pages were allocated for | |
673 | * @pages: array of pages to be freed, indexed by pcpu_page_idx() | |
674 | * @populated: populated bitmap | |
675 | * @page_start: page index of the first page to be freed | |
676 | * @page_end: page index of the last page to be freed + 1 | |
677 | * | |
678 | * Free pages [@page_start and @page_end) in @pages for all units. | |
679 | * The pages were allocated for @chunk. | |
680 | */ | |
681 | static void pcpu_free_pages(struct pcpu_chunk *chunk, | |
682 | struct page **pages, unsigned long *populated, | |
683 | int page_start, int page_end) | |
684 | { | |
685 | unsigned int cpu; | |
686 | int i; | |
687 | ||
688 | for_each_possible_cpu(cpu) { | |
689 | for (i = page_start; i < page_end; i++) { | |
690 | struct page *page = pages[pcpu_page_idx(cpu, i)]; | |
691 | ||
692 | if (page) | |
693 | __free_page(page); | |
694 | } | |
695 | } | |
fbf59bc9 TH |
696 | } |
697 | ||
698 | /** | |
ce3141a2 TH |
699 | * pcpu_alloc_pages - allocates pages for @chunk |
700 | * @chunk: target chunk | |
701 | * @pages: array to put the allocated pages into, indexed by pcpu_page_idx() | |
702 | * @populated: populated bitmap | |
703 | * @page_start: page index of the first page to be allocated | |
704 | * @page_end: page index of the last page to be allocated + 1 | |
705 | * | |
706 | * Allocate pages [@page_start,@page_end) into @pages for all units. | |
707 | * The allocation is for @chunk. Percpu core doesn't care about the | |
708 | * content of @pages and will pass it verbatim to pcpu_map_pages(). | |
fbf59bc9 | 709 | */ |
ce3141a2 TH |
710 | static int pcpu_alloc_pages(struct pcpu_chunk *chunk, |
711 | struct page **pages, unsigned long *populated, | |
712 | int page_start, int page_end) | |
fbf59bc9 | 713 | { |
ce3141a2 | 714 | const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD; |
fbf59bc9 TH |
715 | unsigned int cpu; |
716 | int i; | |
717 | ||
ce3141a2 TH |
718 | for_each_possible_cpu(cpu) { |
719 | for (i = page_start; i < page_end; i++) { | |
720 | struct page **pagep = &pages[pcpu_page_idx(cpu, i)]; | |
721 | ||
722 | *pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0); | |
723 | if (!*pagep) { | |
724 | pcpu_free_pages(chunk, pages, populated, | |
725 | page_start, page_end); | |
726 | return -ENOMEM; | |
727 | } | |
728 | } | |
729 | } | |
730 | return 0; | |
731 | } | |
fbf59bc9 | 732 | |
ce3141a2 TH |
733 | /** |
734 | * pcpu_pre_unmap_flush - flush cache prior to unmapping | |
735 | * @chunk: chunk the regions to be flushed belongs to | |
736 | * @page_start: page index of the first page to be flushed | |
737 | * @page_end: page index of the last page to be flushed + 1 | |
738 | * | |
739 | * Pages in [@page_start,@page_end) of @chunk are about to be | |
740 | * unmapped. Flush cache. As each flushing trial can be very | |
741 | * expensive, issue flush on the whole region at once rather than | |
742 | * doing it for each cpu. This could be an overkill but is more | |
743 | * scalable. | |
744 | */ | |
745 | static void pcpu_pre_unmap_flush(struct pcpu_chunk *chunk, | |
746 | int page_start, int page_end) | |
747 | { | |
2f39e637 TH |
748 | flush_cache_vunmap( |
749 | pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start), | |
750 | pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end)); | |
ce3141a2 TH |
751 | } |
752 | ||
753 | static void __pcpu_unmap_pages(unsigned long addr, int nr_pages) | |
754 | { | |
755 | unmap_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT); | |
756 | } | |
fbf59bc9 | 757 | |
ce3141a2 TH |
758 | /** |
759 | * pcpu_unmap_pages - unmap pages out of a pcpu_chunk | |
fbf59bc9 | 760 | * @chunk: chunk of interest |
ce3141a2 TH |
761 | * @pages: pages array which can be used to pass information to free |
762 | * @populated: populated bitmap | |
fbf59bc9 TH |
763 | * @page_start: page index of the first page to unmap |
764 | * @page_end: page index of the last page to unmap + 1 | |
fbf59bc9 TH |
765 | * |
766 | * For each cpu, unmap pages [@page_start,@page_end) out of @chunk. | |
ce3141a2 TH |
767 | * Corresponding elements in @pages were cleared by the caller and can |
768 | * be used to carry information to pcpu_free_pages() which will be | |
769 | * called after all unmaps are finished. The caller should call | |
770 | * proper pre/post flush functions. | |
fbf59bc9 | 771 | */ |
ce3141a2 TH |
772 | static void pcpu_unmap_pages(struct pcpu_chunk *chunk, |
773 | struct page **pages, unsigned long *populated, | |
774 | int page_start, int page_end) | |
fbf59bc9 | 775 | { |
fbf59bc9 | 776 | unsigned int cpu; |
ce3141a2 | 777 | int i; |
fbf59bc9 | 778 | |
ce3141a2 TH |
779 | for_each_possible_cpu(cpu) { |
780 | for (i = page_start; i < page_end; i++) { | |
781 | struct page *page; | |
fbf59bc9 | 782 | |
ce3141a2 TH |
783 | page = pcpu_chunk_page(chunk, cpu, i); |
784 | WARN_ON(!page); | |
785 | pages[pcpu_page_idx(cpu, i)] = page; | |
fbf59bc9 | 786 | } |
ce3141a2 TH |
787 | __pcpu_unmap_pages(pcpu_chunk_addr(chunk, cpu, page_start), |
788 | page_end - page_start); | |
fbf59bc9 TH |
789 | } |
790 | ||
ce3141a2 TH |
791 | for (i = page_start; i < page_end; i++) |
792 | __clear_bit(i, populated); | |
793 | } | |
794 | ||
795 | /** | |
796 | * pcpu_post_unmap_tlb_flush - flush TLB after unmapping | |
797 | * @chunk: pcpu_chunk the regions to be flushed belong to | |
798 | * @page_start: page index of the first page to be flushed | |
799 | * @page_end: page index of the last page to be flushed + 1 | |
800 | * | |
801 | * Pages [@page_start,@page_end) of @chunk have been unmapped. Flush | |
802 | * TLB for the regions. This can be skipped if the area is to be | |
803 | * returned to vmalloc as vmalloc will handle TLB flushing lazily. | |
804 | * | |
805 | * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once | |
806 | * for the whole region. | |
807 | */ | |
808 | static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk, | |
809 | int page_start, int page_end) | |
810 | { | |
2f39e637 TH |
811 | flush_tlb_kernel_range( |
812 | pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start), | |
813 | pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end)); | |
fbf59bc9 TH |
814 | } |
815 | ||
c8a51be4 TH |
816 | static int __pcpu_map_pages(unsigned long addr, struct page **pages, |
817 | int nr_pages) | |
818 | { | |
819 | return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT, | |
820 | PAGE_KERNEL, pages); | |
fbf59bc9 TH |
821 | } |
822 | ||
823 | /** | |
ce3141a2 | 824 | * pcpu_map_pages - map pages into a pcpu_chunk |
fbf59bc9 | 825 | * @chunk: chunk of interest |
ce3141a2 TH |
826 | * @pages: pages array containing pages to be mapped |
827 | * @populated: populated bitmap | |
fbf59bc9 TH |
828 | * @page_start: page index of the first page to map |
829 | * @page_end: page index of the last page to map + 1 | |
830 | * | |
ce3141a2 TH |
831 | * For each cpu, map pages [@page_start,@page_end) into @chunk. The |
832 | * caller is responsible for calling pcpu_post_map_flush() after all | |
833 | * mappings are complete. | |
834 | * | |
835 | * This function is responsible for setting corresponding bits in | |
836 | * @chunk->populated bitmap and whatever is necessary for reverse | |
837 | * lookup (addr -> chunk). | |
fbf59bc9 | 838 | */ |
ce3141a2 TH |
839 | static int pcpu_map_pages(struct pcpu_chunk *chunk, |
840 | struct page **pages, unsigned long *populated, | |
841 | int page_start, int page_end) | |
fbf59bc9 | 842 | { |
ce3141a2 TH |
843 | unsigned int cpu, tcpu; |
844 | int i, err; | |
8d408b4b | 845 | |
fbf59bc9 | 846 | for_each_possible_cpu(cpu) { |
c8a51be4 | 847 | err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start), |
ce3141a2 | 848 | &pages[pcpu_page_idx(cpu, page_start)], |
c8a51be4 | 849 | page_end - page_start); |
fbf59bc9 | 850 | if (err < 0) |
ce3141a2 | 851 | goto err; |
c8a51be4 TH |
852 | } |
853 | ||
ce3141a2 TH |
854 | /* mapping successful, link chunk and mark populated */ |
855 | for (i = page_start; i < page_end; i++) { | |
856 | for_each_possible_cpu(cpu) | |
857 | pcpu_set_page_chunk(pages[pcpu_page_idx(cpu, i)], | |
858 | chunk); | |
859 | __set_bit(i, populated); | |
fbf59bc9 TH |
860 | } |
861 | ||
fbf59bc9 | 862 | return 0; |
ce3141a2 TH |
863 | |
864 | err: | |
865 | for_each_possible_cpu(tcpu) { | |
866 | if (tcpu == cpu) | |
867 | break; | |
868 | __pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start), | |
869 | page_end - page_start); | |
870 | } | |
871 | return err; | |
872 | } | |
873 | ||
874 | /** | |
875 | * pcpu_post_map_flush - flush cache after mapping | |
876 | * @chunk: pcpu_chunk the regions to be flushed belong to | |
877 | * @page_start: page index of the first page to be flushed | |
878 | * @page_end: page index of the last page to be flushed + 1 | |
879 | * | |
880 | * Pages [@page_start,@page_end) of @chunk have been mapped. Flush | |
881 | * cache. | |
882 | * | |
883 | * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once | |
884 | * for the whole region. | |
885 | */ | |
886 | static void pcpu_post_map_flush(struct pcpu_chunk *chunk, | |
887 | int page_start, int page_end) | |
888 | { | |
2f39e637 TH |
889 | flush_cache_vmap( |
890 | pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start), | |
891 | pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end)); | |
c8a51be4 TH |
892 | } |
893 | ||
fbf59bc9 TH |
894 | /** |
895 | * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk | |
896 | * @chunk: chunk to depopulate | |
897 | * @off: offset to the area to depopulate | |
cae3aeb8 | 898 | * @size: size of the area to depopulate in bytes |
fbf59bc9 TH |
899 | * @flush: whether to flush cache and tlb or not |
900 | * | |
901 | * For each cpu, depopulate and unmap pages [@page_start,@page_end) | |
902 | * from @chunk. If @flush is true, vcache is flushed before unmapping | |
903 | * and tlb after. | |
ccea34b5 TH |
904 | * |
905 | * CONTEXT: | |
906 | * pcpu_alloc_mutex. | |
fbf59bc9 | 907 | */ |
ce3141a2 | 908 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size) |
fbf59bc9 TH |
909 | { |
910 | int page_start = PFN_DOWN(off); | |
911 | int page_end = PFN_UP(off + size); | |
ce3141a2 TH |
912 | struct page **pages; |
913 | unsigned long *populated; | |
914 | int rs, re; | |
915 | ||
916 | /* quick path, check whether it's empty already */ | |
917 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { | |
918 | if (rs == page_start && re == page_end) | |
919 | return; | |
920 | break; | |
921 | } | |
fbf59bc9 | 922 | |
ce3141a2 TH |
923 | /* immutable chunks can't be depopulated */ |
924 | WARN_ON(chunk->immutable); | |
fbf59bc9 | 925 | |
ce3141a2 TH |
926 | /* |
927 | * If control reaches here, there must have been at least one | |
928 | * successful population attempt so the temp pages array must | |
929 | * be available now. | |
930 | */ | |
931 | pages = pcpu_get_pages_and_bitmap(chunk, &populated, false); | |
932 | BUG_ON(!pages); | |
fbf59bc9 | 933 | |
ce3141a2 TH |
934 | /* unmap and free */ |
935 | pcpu_pre_unmap_flush(chunk, page_start, page_end); | |
fbf59bc9 | 936 | |
ce3141a2 TH |
937 | pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) |
938 | pcpu_unmap_pages(chunk, pages, populated, rs, re); | |
fbf59bc9 | 939 | |
ce3141a2 TH |
940 | /* no need to flush tlb, vmalloc will handle it lazily */ |
941 | ||
942 | pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) | |
943 | pcpu_free_pages(chunk, pages, populated, rs, re); | |
fbf59bc9 | 944 | |
ce3141a2 TH |
945 | /* commit new bitmap */ |
946 | bitmap_copy(chunk->populated, populated, pcpu_unit_pages); | |
fbf59bc9 TH |
947 | } |
948 | ||
949 | /** | |
950 | * pcpu_populate_chunk - populate and map an area of a pcpu_chunk | |
951 | * @chunk: chunk of interest | |
952 | * @off: offset to the area to populate | |
cae3aeb8 | 953 | * @size: size of the area to populate in bytes |
fbf59bc9 TH |
954 | * |
955 | * For each cpu, populate and map pages [@page_start,@page_end) into | |
956 | * @chunk. The area is cleared on return. | |
ccea34b5 TH |
957 | * |
958 | * CONTEXT: | |
959 | * pcpu_alloc_mutex, does GFP_KERNEL allocation. | |
fbf59bc9 TH |
960 | */ |
961 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size) | |
962 | { | |
fbf59bc9 TH |
963 | int page_start = PFN_DOWN(off); |
964 | int page_end = PFN_UP(off + size); | |
ce3141a2 TH |
965 | int free_end = page_start, unmap_end = page_start; |
966 | struct page **pages; | |
967 | unsigned long *populated; | |
fbf59bc9 | 968 | unsigned int cpu; |
ce3141a2 | 969 | int rs, re, rc; |
fbf59bc9 | 970 | |
ce3141a2 TH |
971 | /* quick path, check whether all pages are already there */ |
972 | pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) { | |
973 | if (rs == page_start && re == page_end) | |
974 | goto clear; | |
975 | break; | |
976 | } | |
fbf59bc9 | 977 | |
ce3141a2 TH |
978 | /* need to allocate and map pages, this chunk can't be immutable */ |
979 | WARN_ON(chunk->immutable); | |
fbf59bc9 | 980 | |
ce3141a2 TH |
981 | pages = pcpu_get_pages_and_bitmap(chunk, &populated, true); |
982 | if (!pages) | |
983 | return -ENOMEM; | |
fbf59bc9 | 984 | |
ce3141a2 TH |
985 | /* alloc and map */ |
986 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { | |
987 | rc = pcpu_alloc_pages(chunk, pages, populated, rs, re); | |
988 | if (rc) | |
989 | goto err_free; | |
990 | free_end = re; | |
fbf59bc9 TH |
991 | } |
992 | ||
ce3141a2 TH |
993 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { |
994 | rc = pcpu_map_pages(chunk, pages, populated, rs, re); | |
995 | if (rc) | |
996 | goto err_unmap; | |
997 | unmap_end = re; | |
998 | } | |
999 | pcpu_post_map_flush(chunk, page_start, page_end); | |
fbf59bc9 | 1000 | |
ce3141a2 TH |
1001 | /* commit new bitmap */ |
1002 | bitmap_copy(chunk->populated, populated, pcpu_unit_pages); | |
1003 | clear: | |
fbf59bc9 | 1004 | for_each_possible_cpu(cpu) |
2f39e637 | 1005 | memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); |
fbf59bc9 | 1006 | return 0; |
ce3141a2 TH |
1007 | |
1008 | err_unmap: | |
1009 | pcpu_pre_unmap_flush(chunk, page_start, unmap_end); | |
1010 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, unmap_end) | |
1011 | pcpu_unmap_pages(chunk, pages, populated, rs, re); | |
1012 | pcpu_post_unmap_tlb_flush(chunk, page_start, unmap_end); | |
1013 | err_free: | |
1014 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, free_end) | |
1015 | pcpu_free_pages(chunk, pages, populated, rs, re); | |
1016 | return rc; | |
fbf59bc9 TH |
1017 | } |
1018 | ||
1019 | static void free_pcpu_chunk(struct pcpu_chunk *chunk) | |
1020 | { | |
1021 | if (!chunk) | |
1022 | return; | |
6563297c TH |
1023 | if (chunk->vms) |
1024 | pcpu_free_vm_areas(chunk->vms, pcpu_nr_groups); | |
1880d93b | 1025 | pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0])); |
fbf59bc9 TH |
1026 | kfree(chunk); |
1027 | } | |
1028 | ||
1029 | static struct pcpu_chunk *alloc_pcpu_chunk(void) | |
1030 | { | |
1031 | struct pcpu_chunk *chunk; | |
1032 | ||
1033 | chunk = kzalloc(pcpu_chunk_struct_size, GFP_KERNEL); | |
1034 | if (!chunk) | |
1035 | return NULL; | |
1036 | ||
1880d93b | 1037 | chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0])); |
fbf59bc9 TH |
1038 | chunk->map_alloc = PCPU_DFL_MAP_ALLOC; |
1039 | chunk->map[chunk->map_used++] = pcpu_unit_size; | |
1040 | ||
6563297c TH |
1041 | chunk->vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes, |
1042 | pcpu_nr_groups, pcpu_atom_size, | |
1043 | GFP_KERNEL); | |
1044 | if (!chunk->vms) { | |
fbf59bc9 TH |
1045 | free_pcpu_chunk(chunk); |
1046 | return NULL; | |
1047 | } | |
1048 | ||
1049 | INIT_LIST_HEAD(&chunk->list); | |
1050 | chunk->free_size = pcpu_unit_size; | |
1051 | chunk->contig_hint = pcpu_unit_size; | |
6563297c | 1052 | chunk->base_addr = chunk->vms[0]->addr - pcpu_group_offsets[0]; |
fbf59bc9 TH |
1053 | |
1054 | return chunk; | |
1055 | } | |
1056 | ||
1057 | /** | |
edcb4639 | 1058 | * pcpu_alloc - the percpu allocator |
cae3aeb8 | 1059 | * @size: size of area to allocate in bytes |
fbf59bc9 | 1060 | * @align: alignment of area (max PAGE_SIZE) |
edcb4639 | 1061 | * @reserved: allocate from the reserved chunk if available |
fbf59bc9 | 1062 | * |
ccea34b5 TH |
1063 | * Allocate percpu area of @size bytes aligned at @align. |
1064 | * | |
1065 | * CONTEXT: | |
1066 | * Does GFP_KERNEL allocation. | |
fbf59bc9 TH |
1067 | * |
1068 | * RETURNS: | |
1069 | * Percpu pointer to the allocated area on success, NULL on failure. | |
1070 | */ | |
edcb4639 | 1071 | static void *pcpu_alloc(size_t size, size_t align, bool reserved) |
fbf59bc9 | 1072 | { |
f2badb0c | 1073 | static int warn_limit = 10; |
fbf59bc9 | 1074 | struct pcpu_chunk *chunk; |
f2badb0c | 1075 | const char *err; |
833af842 | 1076 | int slot, off, new_alloc; |
403a91b1 | 1077 | unsigned long flags; |
fbf59bc9 | 1078 | |
8d408b4b | 1079 | if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { |
fbf59bc9 TH |
1080 | WARN(true, "illegal size (%zu) or align (%zu) for " |
1081 | "percpu allocation\n", size, align); | |
1082 | return NULL; | |
1083 | } | |
1084 | ||
ccea34b5 | 1085 | mutex_lock(&pcpu_alloc_mutex); |
403a91b1 | 1086 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 1087 | |
edcb4639 TH |
1088 | /* serve reserved allocations from the reserved chunk if available */ |
1089 | if (reserved && pcpu_reserved_chunk) { | |
1090 | chunk = pcpu_reserved_chunk; | |
833af842 TH |
1091 | |
1092 | if (size > chunk->contig_hint) { | |
1093 | err = "alloc from reserved chunk failed"; | |
ccea34b5 | 1094 | goto fail_unlock; |
f2badb0c | 1095 | } |
833af842 TH |
1096 | |
1097 | while ((new_alloc = pcpu_need_to_extend(chunk))) { | |
1098 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
1099 | if (pcpu_extend_area_map(chunk, new_alloc) < 0) { | |
1100 | err = "failed to extend area map of reserved chunk"; | |
1101 | goto fail_unlock_mutex; | |
1102 | } | |
1103 | spin_lock_irqsave(&pcpu_lock, flags); | |
1104 | } | |
1105 | ||
edcb4639 TH |
1106 | off = pcpu_alloc_area(chunk, size, align); |
1107 | if (off >= 0) | |
1108 | goto area_found; | |
833af842 | 1109 | |
f2badb0c | 1110 | err = "alloc from reserved chunk failed"; |
ccea34b5 | 1111 | goto fail_unlock; |
edcb4639 TH |
1112 | } |
1113 | ||
ccea34b5 | 1114 | restart: |
edcb4639 | 1115 | /* search through normal chunks */ |
fbf59bc9 TH |
1116 | for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { |
1117 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { | |
1118 | if (size > chunk->contig_hint) | |
1119 | continue; | |
ccea34b5 | 1120 | |
833af842 TH |
1121 | new_alloc = pcpu_need_to_extend(chunk); |
1122 | if (new_alloc) { | |
1123 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
1124 | if (pcpu_extend_area_map(chunk, | |
1125 | new_alloc) < 0) { | |
1126 | err = "failed to extend area map"; | |
1127 | goto fail_unlock_mutex; | |
1128 | } | |
1129 | spin_lock_irqsave(&pcpu_lock, flags); | |
1130 | /* | |
1131 | * pcpu_lock has been dropped, need to | |
1132 | * restart cpu_slot list walking. | |
1133 | */ | |
1134 | goto restart; | |
ccea34b5 TH |
1135 | } |
1136 | ||
fbf59bc9 TH |
1137 | off = pcpu_alloc_area(chunk, size, align); |
1138 | if (off >= 0) | |
1139 | goto area_found; | |
fbf59bc9 TH |
1140 | } |
1141 | } | |
1142 | ||
1143 | /* hmmm... no space left, create a new chunk */ | |
403a91b1 | 1144 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 | 1145 | |
fbf59bc9 | 1146 | chunk = alloc_pcpu_chunk(); |
f2badb0c TH |
1147 | if (!chunk) { |
1148 | err = "failed to allocate new chunk"; | |
ccea34b5 | 1149 | goto fail_unlock_mutex; |
f2badb0c | 1150 | } |
ccea34b5 | 1151 | |
403a91b1 | 1152 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 1153 | pcpu_chunk_relocate(chunk, -1); |
ccea34b5 | 1154 | goto restart; |
fbf59bc9 TH |
1155 | |
1156 | area_found: | |
403a91b1 | 1157 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 | 1158 | |
fbf59bc9 TH |
1159 | /* populate, map and clear the area */ |
1160 | if (pcpu_populate_chunk(chunk, off, size)) { | |
403a91b1 | 1161 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 1162 | pcpu_free_area(chunk, off); |
f2badb0c | 1163 | err = "failed to populate"; |
ccea34b5 | 1164 | goto fail_unlock; |
fbf59bc9 TH |
1165 | } |
1166 | ||
ccea34b5 TH |
1167 | mutex_unlock(&pcpu_alloc_mutex); |
1168 | ||
bba174f5 TH |
1169 | /* return address relative to base address */ |
1170 | return __addr_to_pcpu_ptr(chunk->base_addr + off); | |
ccea34b5 TH |
1171 | |
1172 | fail_unlock: | |
403a91b1 | 1173 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 TH |
1174 | fail_unlock_mutex: |
1175 | mutex_unlock(&pcpu_alloc_mutex); | |
f2badb0c TH |
1176 | if (warn_limit) { |
1177 | pr_warning("PERCPU: allocation failed, size=%zu align=%zu, " | |
1178 | "%s\n", size, align, err); | |
1179 | dump_stack(); | |
1180 | if (!--warn_limit) | |
1181 | pr_info("PERCPU: limit reached, disable warning\n"); | |
1182 | } | |
ccea34b5 | 1183 | return NULL; |
fbf59bc9 | 1184 | } |
edcb4639 TH |
1185 | |
1186 | /** | |
1187 | * __alloc_percpu - allocate dynamic percpu area | |
1188 | * @size: size of area to allocate in bytes | |
1189 | * @align: alignment of area (max PAGE_SIZE) | |
1190 | * | |
1191 | * Allocate percpu area of @size bytes aligned at @align. Might | |
1192 | * sleep. Might trigger writeouts. | |
1193 | * | |
ccea34b5 TH |
1194 | * CONTEXT: |
1195 | * Does GFP_KERNEL allocation. | |
1196 | * | |
edcb4639 TH |
1197 | * RETURNS: |
1198 | * Percpu pointer to the allocated area on success, NULL on failure. | |
1199 | */ | |
1200 | void *__alloc_percpu(size_t size, size_t align) | |
1201 | { | |
1202 | return pcpu_alloc(size, align, false); | |
1203 | } | |
fbf59bc9 TH |
1204 | EXPORT_SYMBOL_GPL(__alloc_percpu); |
1205 | ||
edcb4639 TH |
1206 | /** |
1207 | * __alloc_reserved_percpu - allocate reserved percpu area | |
1208 | * @size: size of area to allocate in bytes | |
1209 | * @align: alignment of area (max PAGE_SIZE) | |
1210 | * | |
1211 | * Allocate percpu area of @size bytes aligned at @align from reserved | |
1212 | * percpu area if arch has set it up; otherwise, allocation is served | |
1213 | * from the same dynamic area. Might sleep. Might trigger writeouts. | |
1214 | * | |
ccea34b5 TH |
1215 | * CONTEXT: |
1216 | * Does GFP_KERNEL allocation. | |
1217 | * | |
edcb4639 TH |
1218 | * RETURNS: |
1219 | * Percpu pointer to the allocated area on success, NULL on failure. | |
1220 | */ | |
1221 | void *__alloc_reserved_percpu(size_t size, size_t align) | |
1222 | { | |
1223 | return pcpu_alloc(size, align, true); | |
1224 | } | |
1225 | ||
a56dbddf TH |
1226 | /** |
1227 | * pcpu_reclaim - reclaim fully free chunks, workqueue function | |
1228 | * @work: unused | |
1229 | * | |
1230 | * Reclaim all fully free chunks except for the first one. | |
ccea34b5 TH |
1231 | * |
1232 | * CONTEXT: | |
1233 | * workqueue context. | |
a56dbddf TH |
1234 | */ |
1235 | static void pcpu_reclaim(struct work_struct *work) | |
fbf59bc9 | 1236 | { |
a56dbddf TH |
1237 | LIST_HEAD(todo); |
1238 | struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; | |
1239 | struct pcpu_chunk *chunk, *next; | |
1240 | ||
ccea34b5 TH |
1241 | mutex_lock(&pcpu_alloc_mutex); |
1242 | spin_lock_irq(&pcpu_lock); | |
a56dbddf TH |
1243 | |
1244 | list_for_each_entry_safe(chunk, next, head, list) { | |
1245 | WARN_ON(chunk->immutable); | |
1246 | ||
1247 | /* spare the first one */ | |
1248 | if (chunk == list_first_entry(head, struct pcpu_chunk, list)) | |
1249 | continue; | |
1250 | ||
a56dbddf TH |
1251 | list_move(&chunk->list, &todo); |
1252 | } | |
1253 | ||
ccea34b5 | 1254 | spin_unlock_irq(&pcpu_lock); |
a56dbddf TH |
1255 | |
1256 | list_for_each_entry_safe(chunk, next, &todo, list) { | |
ce3141a2 | 1257 | pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); |
a56dbddf TH |
1258 | free_pcpu_chunk(chunk); |
1259 | } | |
971f3918 TH |
1260 | |
1261 | mutex_unlock(&pcpu_alloc_mutex); | |
fbf59bc9 TH |
1262 | } |
1263 | ||
1264 | /** | |
1265 | * free_percpu - free percpu area | |
1266 | * @ptr: pointer to area to free | |
1267 | * | |
ccea34b5 TH |
1268 | * Free percpu area @ptr. |
1269 | * | |
1270 | * CONTEXT: | |
1271 | * Can be called from atomic context. | |
fbf59bc9 TH |
1272 | */ |
1273 | void free_percpu(void *ptr) | |
1274 | { | |
1275 | void *addr = __pcpu_ptr_to_addr(ptr); | |
1276 | struct pcpu_chunk *chunk; | |
ccea34b5 | 1277 | unsigned long flags; |
fbf59bc9 TH |
1278 | int off; |
1279 | ||
1280 | if (!ptr) | |
1281 | return; | |
1282 | ||
ccea34b5 | 1283 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 TH |
1284 | |
1285 | chunk = pcpu_chunk_addr_search(addr); | |
bba174f5 | 1286 | off = addr - chunk->base_addr; |
fbf59bc9 TH |
1287 | |
1288 | pcpu_free_area(chunk, off); | |
1289 | ||
a56dbddf | 1290 | /* if there are more than one fully free chunks, wake up grim reaper */ |
fbf59bc9 TH |
1291 | if (chunk->free_size == pcpu_unit_size) { |
1292 | struct pcpu_chunk *pos; | |
1293 | ||
a56dbddf | 1294 | list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) |
fbf59bc9 | 1295 | if (pos != chunk) { |
a56dbddf | 1296 | schedule_work(&pcpu_reclaim_work); |
fbf59bc9 TH |
1297 | break; |
1298 | } | |
1299 | } | |
1300 | ||
ccea34b5 | 1301 | spin_unlock_irqrestore(&pcpu_lock, flags); |
fbf59bc9 TH |
1302 | } |
1303 | EXPORT_SYMBOL_GPL(free_percpu); | |
1304 | ||
033e48fb TH |
1305 | static inline size_t pcpu_calc_fc_sizes(size_t static_size, |
1306 | size_t reserved_size, | |
1307 | ssize_t *dyn_sizep) | |
1308 | { | |
1309 | size_t size_sum; | |
1310 | ||
1311 | size_sum = PFN_ALIGN(static_size + reserved_size + | |
1312 | (*dyn_sizep >= 0 ? *dyn_sizep : 0)); | |
1313 | if (*dyn_sizep != 0) | |
1314 | *dyn_sizep = size_sum - static_size - reserved_size; | |
1315 | ||
1316 | return size_sum; | |
1317 | } | |
1318 | ||
fbf59bc9 | 1319 | /** |
fd1e8a1f TH |
1320 | * pcpu_alloc_alloc_info - allocate percpu allocation info |
1321 | * @nr_groups: the number of groups | |
1322 | * @nr_units: the number of units | |
1323 | * | |
1324 | * Allocate ai which is large enough for @nr_groups groups containing | |
1325 | * @nr_units units. The returned ai's groups[0].cpu_map points to the | |
1326 | * cpu_map array which is long enough for @nr_units and filled with | |
1327 | * NR_CPUS. It's the caller's responsibility to initialize cpu_map | |
1328 | * pointer of other groups. | |
1329 | * | |
1330 | * RETURNS: | |
1331 | * Pointer to the allocated pcpu_alloc_info on success, NULL on | |
1332 | * failure. | |
1333 | */ | |
1334 | struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, | |
1335 | int nr_units) | |
1336 | { | |
1337 | struct pcpu_alloc_info *ai; | |
1338 | size_t base_size, ai_size; | |
1339 | void *ptr; | |
1340 | int unit; | |
1341 | ||
1342 | base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), | |
1343 | __alignof__(ai->groups[0].cpu_map[0])); | |
1344 | ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); | |
1345 | ||
1346 | ptr = alloc_bootmem_nopanic(PFN_ALIGN(ai_size)); | |
1347 | if (!ptr) | |
1348 | return NULL; | |
1349 | ai = ptr; | |
1350 | ptr += base_size; | |
1351 | ||
1352 | ai->groups[0].cpu_map = ptr; | |
1353 | ||
1354 | for (unit = 0; unit < nr_units; unit++) | |
1355 | ai->groups[0].cpu_map[unit] = NR_CPUS; | |
1356 | ||
1357 | ai->nr_groups = nr_groups; | |
1358 | ai->__ai_size = PFN_ALIGN(ai_size); | |
1359 | ||
1360 | return ai; | |
1361 | } | |
1362 | ||
1363 | /** | |
1364 | * pcpu_free_alloc_info - free percpu allocation info | |
1365 | * @ai: pcpu_alloc_info to free | |
1366 | * | |
1367 | * Free @ai which was allocated by pcpu_alloc_alloc_info(). | |
1368 | */ | |
1369 | void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) | |
1370 | { | |
1371 | free_bootmem(__pa(ai), ai->__ai_size); | |
1372 | } | |
1373 | ||
1374 | /** | |
1375 | * pcpu_build_alloc_info - build alloc_info considering distances between CPUs | |
edcb4639 | 1376 | * @reserved_size: the size of reserved percpu area in bytes |
cafe8816 | 1377 | * @dyn_size: free size for dynamic allocation in bytes, -1 for auto |
fd1e8a1f TH |
1378 | * @atom_size: allocation atom size |
1379 | * @cpu_distance_fn: callback to determine distance between cpus, optional | |
033e48fb | 1380 | * |
fd1e8a1f TH |
1381 | * This function determines grouping of units, their mappings to cpus |
1382 | * and other parameters considering needed percpu size, allocation | |
1383 | * atom size and distances between CPUs. | |
033e48fb | 1384 | * |
fd1e8a1f TH |
1385 | * Groups are always mutliples of atom size and CPUs which are of |
1386 | * LOCAL_DISTANCE both ways are grouped together and share space for | |
1387 | * units in the same group. The returned configuration is guaranteed | |
1388 | * to have CPUs on different nodes on different groups and >=75% usage | |
1389 | * of allocated virtual address space. | |
033e48fb TH |
1390 | * |
1391 | * RETURNS: | |
fd1e8a1f TH |
1392 | * On success, pointer to the new allocation_info is returned. On |
1393 | * failure, ERR_PTR value is returned. | |
033e48fb | 1394 | */ |
fd1e8a1f TH |
1395 | struct pcpu_alloc_info * __init pcpu_build_alloc_info( |
1396 | size_t reserved_size, ssize_t dyn_size, | |
1397 | size_t atom_size, | |
1398 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn) | |
033e48fb TH |
1399 | { |
1400 | static int group_map[NR_CPUS] __initdata; | |
1401 | static int group_cnt[NR_CPUS] __initdata; | |
1402 | const size_t static_size = __per_cpu_end - __per_cpu_start; | |
fd1e8a1f | 1403 | int group_cnt_max = 0, nr_groups = 1, nr_units = 0; |
033e48fb TH |
1404 | size_t size_sum, min_unit_size, alloc_size; |
1405 | int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ | |
fd1e8a1f | 1406 | int last_allocs, group, unit; |
033e48fb | 1407 | unsigned int cpu, tcpu; |
fd1e8a1f TH |
1408 | struct pcpu_alloc_info *ai; |
1409 | unsigned int *cpu_map; | |
033e48fb | 1410 | |
fb59e72e TH |
1411 | /* this function may be called multiple times */ |
1412 | memset(group_map, 0, sizeof(group_map)); | |
1413 | memset(group_cnt, 0, sizeof(group_map)); | |
1414 | ||
033e48fb TH |
1415 | /* |
1416 | * Determine min_unit_size, alloc_size and max_upa such that | |
fd1e8a1f | 1417 | * alloc_size is multiple of atom_size and is the smallest |
033e48fb TH |
1418 | * which can accomodate 4k aligned segments which are equal to |
1419 | * or larger than min_unit_size. | |
1420 | */ | |
fd1e8a1f | 1421 | size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size); |
033e48fb TH |
1422 | min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); |
1423 | ||
fd1e8a1f | 1424 | alloc_size = roundup(min_unit_size, atom_size); |
033e48fb TH |
1425 | upa = alloc_size / min_unit_size; |
1426 | while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) | |
1427 | upa--; | |
1428 | max_upa = upa; | |
1429 | ||
1430 | /* group cpus according to their proximity */ | |
1431 | for_each_possible_cpu(cpu) { | |
1432 | group = 0; | |
1433 | next_group: | |
1434 | for_each_possible_cpu(tcpu) { | |
1435 | if (cpu == tcpu) | |
1436 | break; | |
fd1e8a1f | 1437 | if (group_map[tcpu] == group && cpu_distance_fn && |
033e48fb TH |
1438 | (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || |
1439 | cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { | |
1440 | group++; | |
fd1e8a1f | 1441 | nr_groups = max(nr_groups, group + 1); |
033e48fb TH |
1442 | goto next_group; |
1443 | } | |
1444 | } | |
1445 | group_map[cpu] = group; | |
1446 | group_cnt[group]++; | |
1447 | group_cnt_max = max(group_cnt_max, group_cnt[group]); | |
1448 | } | |
1449 | ||
1450 | /* | |
1451 | * Expand unit size until address space usage goes over 75% | |
1452 | * and then as much as possible without using more address | |
1453 | * space. | |
1454 | */ | |
1455 | last_allocs = INT_MAX; | |
1456 | for (upa = max_upa; upa; upa--) { | |
1457 | int allocs = 0, wasted = 0; | |
1458 | ||
1459 | if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) | |
1460 | continue; | |
1461 | ||
fd1e8a1f | 1462 | for (group = 0; group < nr_groups; group++) { |
033e48fb TH |
1463 | int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); |
1464 | allocs += this_allocs; | |
1465 | wasted += this_allocs * upa - group_cnt[group]; | |
1466 | } | |
1467 | ||
1468 | /* | |
1469 | * Don't accept if wastage is over 25%. The | |
1470 | * greater-than comparison ensures upa==1 always | |
1471 | * passes the following check. | |
1472 | */ | |
1473 | if (wasted > num_possible_cpus() / 3) | |
1474 | continue; | |
1475 | ||
1476 | /* and then don't consume more memory */ | |
1477 | if (allocs > last_allocs) | |
1478 | break; | |
1479 | last_allocs = allocs; | |
1480 | best_upa = upa; | |
1481 | } | |
fd1e8a1f TH |
1482 | upa = best_upa; |
1483 | ||
1484 | /* allocate and fill alloc_info */ | |
1485 | for (group = 0; group < nr_groups; group++) | |
1486 | nr_units += roundup(group_cnt[group], upa); | |
1487 | ||
1488 | ai = pcpu_alloc_alloc_info(nr_groups, nr_units); | |
1489 | if (!ai) | |
1490 | return ERR_PTR(-ENOMEM); | |
1491 | cpu_map = ai->groups[0].cpu_map; | |
1492 | ||
1493 | for (group = 0; group < nr_groups; group++) { | |
1494 | ai->groups[group].cpu_map = cpu_map; | |
1495 | cpu_map += roundup(group_cnt[group], upa); | |
1496 | } | |
1497 | ||
1498 | ai->static_size = static_size; | |
1499 | ai->reserved_size = reserved_size; | |
1500 | ai->dyn_size = dyn_size; | |
1501 | ai->unit_size = alloc_size / upa; | |
1502 | ai->atom_size = atom_size; | |
1503 | ai->alloc_size = alloc_size; | |
1504 | ||
1505 | for (group = 0, unit = 0; group_cnt[group]; group++) { | |
1506 | struct pcpu_group_info *gi = &ai->groups[group]; | |
1507 | ||
1508 | /* | |
1509 | * Initialize base_offset as if all groups are located | |
1510 | * back-to-back. The caller should update this to | |
1511 | * reflect actual allocation. | |
1512 | */ | |
1513 | gi->base_offset = unit * ai->unit_size; | |
033e48fb | 1514 | |
033e48fb TH |
1515 | for_each_possible_cpu(cpu) |
1516 | if (group_map[cpu] == group) | |
fd1e8a1f TH |
1517 | gi->cpu_map[gi->nr_units++] = cpu; |
1518 | gi->nr_units = roundup(gi->nr_units, upa); | |
1519 | unit += gi->nr_units; | |
033e48fb | 1520 | } |
fd1e8a1f | 1521 | BUG_ON(unit != nr_units); |
033e48fb | 1522 | |
fd1e8a1f | 1523 | return ai; |
033e48fb TH |
1524 | } |
1525 | ||
fd1e8a1f TH |
1526 | /** |
1527 | * pcpu_dump_alloc_info - print out information about pcpu_alloc_info | |
1528 | * @lvl: loglevel | |
1529 | * @ai: allocation info to dump | |
1530 | * | |
1531 | * Print out information about @ai using loglevel @lvl. | |
1532 | */ | |
1533 | static void pcpu_dump_alloc_info(const char *lvl, | |
1534 | const struct pcpu_alloc_info *ai) | |
033e48fb | 1535 | { |
fd1e8a1f | 1536 | int group_width = 1, cpu_width = 1, width; |
033e48fb | 1537 | char empty_str[] = "--------"; |
fd1e8a1f TH |
1538 | int alloc = 0, alloc_end = 0; |
1539 | int group, v; | |
1540 | int upa, apl; /* units per alloc, allocs per line */ | |
1541 | ||
1542 | v = ai->nr_groups; | |
1543 | while (v /= 10) | |
1544 | group_width++; | |
033e48fb | 1545 | |
fd1e8a1f | 1546 | v = num_possible_cpus(); |
033e48fb | 1547 | while (v /= 10) |
fd1e8a1f TH |
1548 | cpu_width++; |
1549 | empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; | |
033e48fb | 1550 | |
fd1e8a1f TH |
1551 | upa = ai->alloc_size / ai->unit_size; |
1552 | width = upa * (cpu_width + 1) + group_width + 3; | |
1553 | apl = rounddown_pow_of_two(max(60 / width, 1)); | |
033e48fb | 1554 | |
fd1e8a1f TH |
1555 | printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", |
1556 | lvl, ai->static_size, ai->reserved_size, ai->dyn_size, | |
1557 | ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); | |
033e48fb | 1558 | |
fd1e8a1f TH |
1559 | for (group = 0; group < ai->nr_groups; group++) { |
1560 | const struct pcpu_group_info *gi = &ai->groups[group]; | |
1561 | int unit = 0, unit_end = 0; | |
1562 | ||
1563 | BUG_ON(gi->nr_units % upa); | |
1564 | for (alloc_end += gi->nr_units / upa; | |
1565 | alloc < alloc_end; alloc++) { | |
1566 | if (!(alloc % apl)) { | |
033e48fb | 1567 | printk("\n"); |
fd1e8a1f TH |
1568 | printk("%spcpu-alloc: ", lvl); |
1569 | } | |
1570 | printk("[%0*d] ", group_width, group); | |
1571 | ||
1572 | for (unit_end += upa; unit < unit_end; unit++) | |
1573 | if (gi->cpu_map[unit] != NR_CPUS) | |
1574 | printk("%0*d ", cpu_width, | |
1575 | gi->cpu_map[unit]); | |
1576 | else | |
1577 | printk("%s ", empty_str); | |
033e48fb | 1578 | } |
033e48fb TH |
1579 | } |
1580 | printk("\n"); | |
1581 | } | |
033e48fb | 1582 | |
fbf59bc9 | 1583 | /** |
8d408b4b | 1584 | * pcpu_setup_first_chunk - initialize the first percpu chunk |
fd1e8a1f | 1585 | * @ai: pcpu_alloc_info describing how to percpu area is shaped |
38a6be52 | 1586 | * @base_addr: mapped address |
8d408b4b TH |
1587 | * |
1588 | * Initialize the first percpu chunk which contains the kernel static | |
1589 | * perpcu area. This function is to be called from arch percpu area | |
38a6be52 | 1590 | * setup path. |
8d408b4b | 1591 | * |
fd1e8a1f TH |
1592 | * @ai contains all information necessary to initialize the first |
1593 | * chunk and prime the dynamic percpu allocator. | |
1594 | * | |
1595 | * @ai->static_size is the size of static percpu area. | |
1596 | * | |
1597 | * @ai->reserved_size, if non-zero, specifies the amount of bytes to | |
edcb4639 TH |
1598 | * reserve after the static area in the first chunk. This reserves |
1599 | * the first chunk such that it's available only through reserved | |
1600 | * percpu allocation. This is primarily used to serve module percpu | |
1601 | * static areas on architectures where the addressing model has | |
1602 | * limited offset range for symbol relocations to guarantee module | |
1603 | * percpu symbols fall inside the relocatable range. | |
1604 | * | |
fd1e8a1f TH |
1605 | * @ai->dyn_size determines the number of bytes available for dynamic |
1606 | * allocation in the first chunk. The area between @ai->static_size + | |
1607 | * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. | |
6074d5b0 | 1608 | * |
fd1e8a1f TH |
1609 | * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE |
1610 | * and equal to or larger than @ai->static_size + @ai->reserved_size + | |
1611 | * @ai->dyn_size. | |
8d408b4b | 1612 | * |
fd1e8a1f TH |
1613 | * @ai->atom_size is the allocation atom size and used as alignment |
1614 | * for vm areas. | |
8d408b4b | 1615 | * |
fd1e8a1f TH |
1616 | * @ai->alloc_size is the allocation size and always multiple of |
1617 | * @ai->atom_size. This is larger than @ai->atom_size if | |
1618 | * @ai->unit_size is larger than @ai->atom_size. | |
1619 | * | |
1620 | * @ai->nr_groups and @ai->groups describe virtual memory layout of | |
1621 | * percpu areas. Units which should be colocated are put into the | |
1622 | * same group. Dynamic VM areas will be allocated according to these | |
1623 | * groupings. If @ai->nr_groups is zero, a single group containing | |
1624 | * all units is assumed. | |
8d408b4b | 1625 | * |
38a6be52 TH |
1626 | * The caller should have mapped the first chunk at @base_addr and |
1627 | * copied static data to each unit. | |
fbf59bc9 | 1628 | * |
edcb4639 TH |
1629 | * If the first chunk ends up with both reserved and dynamic areas, it |
1630 | * is served by two chunks - one to serve the core static and reserved | |
1631 | * areas and the other for the dynamic area. They share the same vm | |
1632 | * and page map but uses different area allocation map to stay away | |
1633 | * from each other. The latter chunk is circulated in the chunk slots | |
1634 | * and available for dynamic allocation like any other chunks. | |
1635 | * | |
fbf59bc9 | 1636 | * RETURNS: |
fb435d52 | 1637 | * 0 on success, -errno on failure. |
fbf59bc9 | 1638 | */ |
fb435d52 TH |
1639 | int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, |
1640 | void *base_addr) | |
fbf59bc9 | 1641 | { |
635b75fc | 1642 | static char cpus_buf[4096] __initdata; |
edcb4639 | 1643 | static int smap[2], dmap[2]; |
fd1e8a1f TH |
1644 | size_t dyn_size = ai->dyn_size; |
1645 | size_t size_sum = ai->static_size + ai->reserved_size + dyn_size; | |
edcb4639 | 1646 | struct pcpu_chunk *schunk, *dchunk = NULL; |
6563297c TH |
1647 | unsigned long *group_offsets; |
1648 | size_t *group_sizes; | |
fb435d52 | 1649 | unsigned long *unit_off; |
fbf59bc9 | 1650 | unsigned int cpu; |
fd1e8a1f TH |
1651 | int *unit_map; |
1652 | int group, unit, i; | |
fbf59bc9 | 1653 | |
635b75fc TH |
1654 | cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask); |
1655 | ||
1656 | #define PCPU_SETUP_BUG_ON(cond) do { \ | |
1657 | if (unlikely(cond)) { \ | |
1658 | pr_emerg("PERCPU: failed to initialize, %s", #cond); \ | |
1659 | pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \ | |
1660 | pcpu_dump_alloc_info(KERN_EMERG, ai); \ | |
1661 | BUG(); \ | |
1662 | } \ | |
1663 | } while (0) | |
1664 | ||
2f39e637 | 1665 | /* sanity checks */ |
edcb4639 TH |
1666 | BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC || |
1667 | ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC); | |
635b75fc TH |
1668 | PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); |
1669 | PCPU_SETUP_BUG_ON(!ai->static_size); | |
1670 | PCPU_SETUP_BUG_ON(!base_addr); | |
1671 | PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); | |
1672 | PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK); | |
1673 | PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); | |
8d408b4b | 1674 | |
6563297c TH |
1675 | /* process group information and build config tables accordingly */ |
1676 | group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0])); | |
1677 | group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0])); | |
fd1e8a1f | 1678 | unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0])); |
fb435d52 | 1679 | unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0])); |
2f39e637 | 1680 | |
fd1e8a1f | 1681 | for (cpu = 0; cpu < nr_cpu_ids; cpu++) |
ffe0d5a5 | 1682 | unit_map[cpu] = UINT_MAX; |
fd1e8a1f | 1683 | pcpu_first_unit_cpu = NR_CPUS; |
2f39e637 | 1684 | |
fd1e8a1f TH |
1685 | for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { |
1686 | const struct pcpu_group_info *gi = &ai->groups[group]; | |
2f39e637 | 1687 | |
6563297c TH |
1688 | group_offsets[group] = gi->base_offset; |
1689 | group_sizes[group] = gi->nr_units * ai->unit_size; | |
1690 | ||
fd1e8a1f TH |
1691 | for (i = 0; i < gi->nr_units; i++) { |
1692 | cpu = gi->cpu_map[i]; | |
1693 | if (cpu == NR_CPUS) | |
1694 | continue; | |
8d408b4b | 1695 | |
635b75fc TH |
1696 | PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids); |
1697 | PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); | |
1698 | PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); | |
fbf59bc9 | 1699 | |
fd1e8a1f | 1700 | unit_map[cpu] = unit + i; |
fb435d52 TH |
1701 | unit_off[cpu] = gi->base_offset + i * ai->unit_size; |
1702 | ||
fd1e8a1f TH |
1703 | if (pcpu_first_unit_cpu == NR_CPUS) |
1704 | pcpu_first_unit_cpu = cpu; | |
1705 | } | |
2f39e637 | 1706 | } |
fd1e8a1f TH |
1707 | pcpu_last_unit_cpu = cpu; |
1708 | pcpu_nr_units = unit; | |
1709 | ||
1710 | for_each_possible_cpu(cpu) | |
635b75fc TH |
1711 | PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); |
1712 | ||
1713 | /* we're done parsing the input, undefine BUG macro and dump config */ | |
1714 | #undef PCPU_SETUP_BUG_ON | |
1715 | pcpu_dump_alloc_info(KERN_INFO, ai); | |
fd1e8a1f | 1716 | |
6563297c TH |
1717 | pcpu_nr_groups = ai->nr_groups; |
1718 | pcpu_group_offsets = group_offsets; | |
1719 | pcpu_group_sizes = group_sizes; | |
fd1e8a1f | 1720 | pcpu_unit_map = unit_map; |
fb435d52 | 1721 | pcpu_unit_offsets = unit_off; |
2f39e637 TH |
1722 | |
1723 | /* determine basic parameters */ | |
fd1e8a1f | 1724 | pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; |
d9b55eeb | 1725 | pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; |
6563297c | 1726 | pcpu_atom_size = ai->atom_size; |
ce3141a2 TH |
1727 | pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + |
1728 | BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); | |
cafe8816 | 1729 | |
d9b55eeb TH |
1730 | /* |
1731 | * Allocate chunk slots. The additional last slot is for | |
1732 | * empty chunks. | |
1733 | */ | |
1734 | pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; | |
fbf59bc9 TH |
1735 | pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0])); |
1736 | for (i = 0; i < pcpu_nr_slots; i++) | |
1737 | INIT_LIST_HEAD(&pcpu_slot[i]); | |
1738 | ||
edcb4639 TH |
1739 | /* |
1740 | * Initialize static chunk. If reserved_size is zero, the | |
1741 | * static chunk covers static area + dynamic allocation area | |
1742 | * in the first chunk. If reserved_size is not zero, it | |
1743 | * covers static area + reserved area (mostly used for module | |
1744 | * static percpu allocation). | |
1745 | */ | |
2441d15c TH |
1746 | schunk = alloc_bootmem(pcpu_chunk_struct_size); |
1747 | INIT_LIST_HEAD(&schunk->list); | |
bba174f5 | 1748 | schunk->base_addr = base_addr; |
61ace7fa TH |
1749 | schunk->map = smap; |
1750 | schunk->map_alloc = ARRAY_SIZE(smap); | |
38a6be52 | 1751 | schunk->immutable = true; |
ce3141a2 | 1752 | bitmap_fill(schunk->populated, pcpu_unit_pages); |
edcb4639 | 1753 | |
fd1e8a1f TH |
1754 | if (ai->reserved_size) { |
1755 | schunk->free_size = ai->reserved_size; | |
ae9e6bc9 | 1756 | pcpu_reserved_chunk = schunk; |
fd1e8a1f | 1757 | pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size; |
edcb4639 TH |
1758 | } else { |
1759 | schunk->free_size = dyn_size; | |
1760 | dyn_size = 0; /* dynamic area covered */ | |
1761 | } | |
2441d15c | 1762 | schunk->contig_hint = schunk->free_size; |
fbf59bc9 | 1763 | |
fd1e8a1f | 1764 | schunk->map[schunk->map_used++] = -ai->static_size; |
61ace7fa TH |
1765 | if (schunk->free_size) |
1766 | schunk->map[schunk->map_used++] = schunk->free_size; | |
1767 | ||
edcb4639 TH |
1768 | /* init dynamic chunk if necessary */ |
1769 | if (dyn_size) { | |
ce3141a2 | 1770 | dchunk = alloc_bootmem(pcpu_chunk_struct_size); |
edcb4639 | 1771 | INIT_LIST_HEAD(&dchunk->list); |
bba174f5 | 1772 | dchunk->base_addr = base_addr; |
edcb4639 TH |
1773 | dchunk->map = dmap; |
1774 | dchunk->map_alloc = ARRAY_SIZE(dmap); | |
38a6be52 | 1775 | dchunk->immutable = true; |
ce3141a2 | 1776 | bitmap_fill(dchunk->populated, pcpu_unit_pages); |
edcb4639 TH |
1777 | |
1778 | dchunk->contig_hint = dchunk->free_size = dyn_size; | |
1779 | dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit; | |
1780 | dchunk->map[dchunk->map_used++] = dchunk->free_size; | |
1781 | } | |
1782 | ||
2441d15c | 1783 | /* link the first chunk in */ |
ae9e6bc9 TH |
1784 | pcpu_first_chunk = dchunk ?: schunk; |
1785 | pcpu_chunk_relocate(pcpu_first_chunk, -1); | |
fbf59bc9 TH |
1786 | |
1787 | /* we're done */ | |
bba174f5 | 1788 | pcpu_base_addr = base_addr; |
fb435d52 | 1789 | return 0; |
fbf59bc9 | 1790 | } |
66c3a757 | 1791 | |
f58dc01b TH |
1792 | const char *pcpu_fc_names[PCPU_FC_NR] __initdata = { |
1793 | [PCPU_FC_AUTO] = "auto", | |
1794 | [PCPU_FC_EMBED] = "embed", | |
1795 | [PCPU_FC_PAGE] = "page", | |
f58dc01b | 1796 | }; |
66c3a757 | 1797 | |
f58dc01b | 1798 | enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; |
66c3a757 | 1799 | |
f58dc01b TH |
1800 | static int __init percpu_alloc_setup(char *str) |
1801 | { | |
1802 | if (0) | |
1803 | /* nada */; | |
1804 | #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK | |
1805 | else if (!strcmp(str, "embed")) | |
1806 | pcpu_chosen_fc = PCPU_FC_EMBED; | |
1807 | #endif | |
1808 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK | |
1809 | else if (!strcmp(str, "page")) | |
1810 | pcpu_chosen_fc = PCPU_FC_PAGE; | |
f58dc01b TH |
1811 | #endif |
1812 | else | |
1813 | pr_warning("PERCPU: unknown allocator %s specified\n", str); | |
66c3a757 | 1814 | |
f58dc01b | 1815 | return 0; |
66c3a757 | 1816 | } |
f58dc01b | 1817 | early_param("percpu_alloc", percpu_alloc_setup); |
66c3a757 | 1818 | |
08fc4580 TH |
1819 | #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ |
1820 | !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) | |
66c3a757 TH |
1821 | /** |
1822 | * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem | |
66c3a757 TH |
1823 | * @reserved_size: the size of reserved percpu area in bytes |
1824 | * @dyn_size: free size for dynamic allocation in bytes, -1 for auto | |
c8826dd5 TH |
1825 | * @atom_size: allocation atom size |
1826 | * @cpu_distance_fn: callback to determine distance between cpus, optional | |
1827 | * @alloc_fn: function to allocate percpu page | |
1828 | * @free_fn: funtion to free percpu page | |
66c3a757 TH |
1829 | * |
1830 | * This is a helper to ease setting up embedded first percpu chunk and | |
1831 | * can be called where pcpu_setup_first_chunk() is expected. | |
1832 | * | |
1833 | * If this function is used to setup the first chunk, it is allocated | |
c8826dd5 TH |
1834 | * by calling @alloc_fn and used as-is without being mapped into |
1835 | * vmalloc area. Allocations are always whole multiples of @atom_size | |
1836 | * aligned to @atom_size. | |
1837 | * | |
1838 | * This enables the first chunk to piggy back on the linear physical | |
1839 | * mapping which often uses larger page size. Please note that this | |
1840 | * can result in very sparse cpu->unit mapping on NUMA machines thus | |
1841 | * requiring large vmalloc address space. Don't use this allocator if | |
1842 | * vmalloc space is not orders of magnitude larger than distances | |
1843 | * between node memory addresses (ie. 32bit NUMA machines). | |
66c3a757 TH |
1844 | * |
1845 | * When @dyn_size is positive, dynamic area might be larger than | |
788e5abc TH |
1846 | * specified to fill page alignment. When @dyn_size is auto, |
1847 | * @dyn_size is just big enough to fill page alignment after static | |
1848 | * and reserved areas. | |
66c3a757 TH |
1849 | * |
1850 | * If the needed size is smaller than the minimum or specified unit | |
c8826dd5 | 1851 | * size, the leftover is returned using @free_fn. |
66c3a757 TH |
1852 | * |
1853 | * RETURNS: | |
fb435d52 | 1854 | * 0 on success, -errno on failure. |
66c3a757 | 1855 | */ |
c8826dd5 TH |
1856 | int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size, |
1857 | size_t atom_size, | |
1858 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn, | |
1859 | pcpu_fc_alloc_fn_t alloc_fn, | |
1860 | pcpu_fc_free_fn_t free_fn) | |
66c3a757 | 1861 | { |
c8826dd5 TH |
1862 | void *base = (void *)ULONG_MAX; |
1863 | void **areas = NULL; | |
fd1e8a1f | 1864 | struct pcpu_alloc_info *ai; |
6ea529a2 | 1865 | size_t size_sum, areas_size, max_distance; |
c8826dd5 | 1866 | int group, i, rc; |
66c3a757 | 1867 | |
c8826dd5 TH |
1868 | ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, |
1869 | cpu_distance_fn); | |
fd1e8a1f TH |
1870 | if (IS_ERR(ai)) |
1871 | return PTR_ERR(ai); | |
66c3a757 | 1872 | |
fd1e8a1f | 1873 | size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; |
c8826dd5 | 1874 | areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); |
fa8a7094 | 1875 | |
c8826dd5 TH |
1876 | areas = alloc_bootmem_nopanic(areas_size); |
1877 | if (!areas) { | |
fb435d52 | 1878 | rc = -ENOMEM; |
c8826dd5 | 1879 | goto out_free; |
fa8a7094 | 1880 | } |
66c3a757 | 1881 | |
c8826dd5 TH |
1882 | /* allocate, copy and determine base address */ |
1883 | for (group = 0; group < ai->nr_groups; group++) { | |
1884 | struct pcpu_group_info *gi = &ai->groups[group]; | |
1885 | unsigned int cpu = NR_CPUS; | |
1886 | void *ptr; | |
1887 | ||
1888 | for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) | |
1889 | cpu = gi->cpu_map[i]; | |
1890 | BUG_ON(cpu == NR_CPUS); | |
1891 | ||
1892 | /* allocate space for the whole group */ | |
1893 | ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); | |
1894 | if (!ptr) { | |
1895 | rc = -ENOMEM; | |
1896 | goto out_free_areas; | |
1897 | } | |
1898 | areas[group] = ptr; | |
fd1e8a1f | 1899 | |
c8826dd5 TH |
1900 | base = min(ptr, base); |
1901 | ||
1902 | for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { | |
1903 | if (gi->cpu_map[i] == NR_CPUS) { | |
1904 | /* unused unit, free whole */ | |
1905 | free_fn(ptr, ai->unit_size); | |
1906 | continue; | |
1907 | } | |
1908 | /* copy and return the unused part */ | |
1909 | memcpy(ptr, __per_cpu_load, ai->static_size); | |
1910 | free_fn(ptr + size_sum, ai->unit_size - size_sum); | |
1911 | } | |
fa8a7094 | 1912 | } |
66c3a757 | 1913 | |
c8826dd5 | 1914 | /* base address is now known, determine group base offsets */ |
6ea529a2 TH |
1915 | max_distance = 0; |
1916 | for (group = 0; group < ai->nr_groups; group++) { | |
c8826dd5 | 1917 | ai->groups[group].base_offset = areas[group] - base; |
1a0c3298 TH |
1918 | max_distance = max_t(size_t, max_distance, |
1919 | ai->groups[group].base_offset); | |
6ea529a2 TH |
1920 | } |
1921 | max_distance += ai->unit_size; | |
1922 | ||
1923 | /* warn if maximum distance is further than 75% of vmalloc space */ | |
1924 | if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) { | |
1a0c3298 | 1925 | pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc " |
6ea529a2 TH |
1926 | "space 0x%lx\n", |
1927 | max_distance, VMALLOC_END - VMALLOC_START); | |
1928 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK | |
1929 | /* and fail if we have fallback */ | |
1930 | rc = -EINVAL; | |
1931 | goto out_free; | |
1932 | #endif | |
1933 | } | |
c8826dd5 | 1934 | |
004018e2 | 1935 | pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", |
fd1e8a1f TH |
1936 | PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, |
1937 | ai->dyn_size, ai->unit_size); | |
d4b95f80 | 1938 | |
fb435d52 | 1939 | rc = pcpu_setup_first_chunk(ai, base); |
c8826dd5 TH |
1940 | goto out_free; |
1941 | ||
1942 | out_free_areas: | |
1943 | for (group = 0; group < ai->nr_groups; group++) | |
1944 | free_fn(areas[group], | |
1945 | ai->groups[group].nr_units * ai->unit_size); | |
1946 | out_free: | |
fd1e8a1f | 1947 | pcpu_free_alloc_info(ai); |
c8826dd5 TH |
1948 | if (areas) |
1949 | free_bootmem(__pa(areas), areas_size); | |
fb435d52 | 1950 | return rc; |
d4b95f80 | 1951 | } |
08fc4580 TH |
1952 | #endif /* CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK || |
1953 | !CONFIG_HAVE_SETUP_PER_CPU_AREA */ | |
d4b95f80 | 1954 | |
08fc4580 | 1955 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK |
d4b95f80 | 1956 | /** |
00ae4064 | 1957 | * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages |
d4b95f80 TH |
1958 | * @reserved_size: the size of reserved percpu area in bytes |
1959 | * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE | |
1960 | * @free_fn: funtion to free percpu page, always called with PAGE_SIZE | |
1961 | * @populate_pte_fn: function to populate pte | |
1962 | * | |
00ae4064 TH |
1963 | * This is a helper to ease setting up page-remapped first percpu |
1964 | * chunk and can be called where pcpu_setup_first_chunk() is expected. | |
d4b95f80 TH |
1965 | * |
1966 | * This is the basic allocator. Static percpu area is allocated | |
1967 | * page-by-page into vmalloc area. | |
1968 | * | |
1969 | * RETURNS: | |
fb435d52 | 1970 | * 0 on success, -errno on failure. |
d4b95f80 | 1971 | */ |
fb435d52 TH |
1972 | int __init pcpu_page_first_chunk(size_t reserved_size, |
1973 | pcpu_fc_alloc_fn_t alloc_fn, | |
1974 | pcpu_fc_free_fn_t free_fn, | |
1975 | pcpu_fc_populate_pte_fn_t populate_pte_fn) | |
d4b95f80 | 1976 | { |
8f05a6a6 | 1977 | static struct vm_struct vm; |
fd1e8a1f | 1978 | struct pcpu_alloc_info *ai; |
00ae4064 | 1979 | char psize_str[16]; |
ce3141a2 | 1980 | int unit_pages; |
d4b95f80 | 1981 | size_t pages_size; |
ce3141a2 | 1982 | struct page **pages; |
fb435d52 | 1983 | int unit, i, j, rc; |
d4b95f80 | 1984 | |
00ae4064 TH |
1985 | snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); |
1986 | ||
fd1e8a1f TH |
1987 | ai = pcpu_build_alloc_info(reserved_size, -1, PAGE_SIZE, NULL); |
1988 | if (IS_ERR(ai)) | |
1989 | return PTR_ERR(ai); | |
1990 | BUG_ON(ai->nr_groups != 1); | |
1991 | BUG_ON(ai->groups[0].nr_units != num_possible_cpus()); | |
1992 | ||
1993 | unit_pages = ai->unit_size >> PAGE_SHIFT; | |
d4b95f80 TH |
1994 | |
1995 | /* unaligned allocations can't be freed, round up to page size */ | |
fd1e8a1f TH |
1996 | pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * |
1997 | sizeof(pages[0])); | |
ce3141a2 | 1998 | pages = alloc_bootmem(pages_size); |
d4b95f80 | 1999 | |
8f05a6a6 | 2000 | /* allocate pages */ |
d4b95f80 | 2001 | j = 0; |
fd1e8a1f | 2002 | for (unit = 0; unit < num_possible_cpus(); unit++) |
ce3141a2 | 2003 | for (i = 0; i < unit_pages; i++) { |
fd1e8a1f | 2004 | unsigned int cpu = ai->groups[0].cpu_map[unit]; |
d4b95f80 TH |
2005 | void *ptr; |
2006 | ||
3cbc8565 | 2007 | ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); |
d4b95f80 | 2008 | if (!ptr) { |
00ae4064 TH |
2009 | pr_warning("PERCPU: failed to allocate %s page " |
2010 | "for cpu%u\n", psize_str, cpu); | |
d4b95f80 TH |
2011 | goto enomem; |
2012 | } | |
ce3141a2 | 2013 | pages[j++] = virt_to_page(ptr); |
d4b95f80 TH |
2014 | } |
2015 | ||
8f05a6a6 TH |
2016 | /* allocate vm area, map the pages and copy static data */ |
2017 | vm.flags = VM_ALLOC; | |
fd1e8a1f | 2018 | vm.size = num_possible_cpus() * ai->unit_size; |
8f05a6a6 TH |
2019 | vm_area_register_early(&vm, PAGE_SIZE); |
2020 | ||
fd1e8a1f | 2021 | for (unit = 0; unit < num_possible_cpus(); unit++) { |
1d9d3257 | 2022 | unsigned long unit_addr = |
fd1e8a1f | 2023 | (unsigned long)vm.addr + unit * ai->unit_size; |
8f05a6a6 | 2024 | |
ce3141a2 | 2025 | for (i = 0; i < unit_pages; i++) |
8f05a6a6 TH |
2026 | populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); |
2027 | ||
2028 | /* pte already populated, the following shouldn't fail */ | |
fb435d52 TH |
2029 | rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], |
2030 | unit_pages); | |
2031 | if (rc < 0) | |
2032 | panic("failed to map percpu area, err=%d\n", rc); | |
66c3a757 | 2033 | |
8f05a6a6 TH |
2034 | /* |
2035 | * FIXME: Archs with virtual cache should flush local | |
2036 | * cache for the linear mapping here - something | |
2037 | * equivalent to flush_cache_vmap() on the local cpu. | |
2038 | * flush_cache_vmap() can't be used as most supporting | |
2039 | * data structures are not set up yet. | |
2040 | */ | |
2041 | ||
2042 | /* copy static data */ | |
fd1e8a1f | 2043 | memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); |
66c3a757 TH |
2044 | } |
2045 | ||
2046 | /* we're ready, commit */ | |
1d9d3257 | 2047 | pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n", |
fd1e8a1f TH |
2048 | unit_pages, psize_str, vm.addr, ai->static_size, |
2049 | ai->reserved_size, ai->dyn_size); | |
d4b95f80 | 2050 | |
fb435d52 | 2051 | rc = pcpu_setup_first_chunk(ai, vm.addr); |
d4b95f80 TH |
2052 | goto out_free_ar; |
2053 | ||
2054 | enomem: | |
2055 | while (--j >= 0) | |
ce3141a2 | 2056 | free_fn(page_address(pages[j]), PAGE_SIZE); |
fb435d52 | 2057 | rc = -ENOMEM; |
d4b95f80 | 2058 | out_free_ar: |
ce3141a2 | 2059 | free_bootmem(__pa(pages), pages_size); |
fd1e8a1f | 2060 | pcpu_free_alloc_info(ai); |
fb435d52 | 2061 | return rc; |
d4b95f80 | 2062 | } |
08fc4580 | 2063 | #endif /* CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK */ |
d4b95f80 | 2064 | |
e74e3962 TH |
2065 | /* |
2066 | * Generic percpu area setup. | |
2067 | * | |
2068 | * The embedding helper is used because its behavior closely resembles | |
2069 | * the original non-dynamic generic percpu area setup. This is | |
2070 | * important because many archs have addressing restrictions and might | |
2071 | * fail if the percpu area is located far away from the previous | |
2072 | * location. As an added bonus, in non-NUMA cases, embedding is | |
2073 | * generally a good idea TLB-wise because percpu area can piggy back | |
2074 | * on the physical linear memory mapping which uses large page | |
2075 | * mappings on applicable archs. | |
2076 | */ | |
2077 | #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA | |
2078 | unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; | |
2079 | EXPORT_SYMBOL(__per_cpu_offset); | |
2080 | ||
c8826dd5 TH |
2081 | static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, |
2082 | size_t align) | |
2083 | { | |
2084 | return __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS)); | |
2085 | } | |
66c3a757 | 2086 | |
c8826dd5 TH |
2087 | static void __init pcpu_dfl_fc_free(void *ptr, size_t size) |
2088 | { | |
2089 | free_bootmem(__pa(ptr), size); | |
2090 | } | |
2091 | ||
e74e3962 TH |
2092 | void __init setup_per_cpu_areas(void) |
2093 | { | |
e74e3962 TH |
2094 | unsigned long delta; |
2095 | unsigned int cpu; | |
fb435d52 | 2096 | int rc; |
e74e3962 TH |
2097 | |
2098 | /* | |
2099 | * Always reserve area for module percpu variables. That's | |
2100 | * what the legacy allocator did. | |
2101 | */ | |
fb435d52 | 2102 | rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, |
c8826dd5 TH |
2103 | PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, |
2104 | pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); | |
fb435d52 | 2105 | if (rc < 0) |
e74e3962 TH |
2106 | panic("Failed to initialized percpu areas."); |
2107 | ||
2108 | delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; | |
2109 | for_each_possible_cpu(cpu) | |
fb435d52 | 2110 | __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; |
66c3a757 | 2111 | } |
e74e3962 | 2112 | #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ |