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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 | |
11 | * chunk is consisted of num_possible_cpus() units and the first chunk | |
12 | * is used for static percpu variables in the kernel image (special | |
13 | * boot time alloc/init handling necessary as these areas need to be | |
14 | * brought up before allocation services are running). Unit grows as | |
15 | * necessary and all units grow or shrink in unison. When a chunk is | |
16 | * filled up, another chunk is allocated. ie. in vmalloc area | |
17 | * | |
18 | * c0 c1 c2 | |
19 | * ------------------- ------------------- ------------ | |
20 | * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u | |
21 | * ------------------- ...... ------------------- .... ------------ | |
22 | * | |
23 | * Allocation is done in offset-size areas of single unit space. Ie, | |
24 | * an area of 512 bytes at 6k in c1 occupies 512 bytes at 6k of c1:u0, | |
25 | * c1:u1, c1:u2 and c1:u3. Percpu access can be done by configuring | |
26 | * percpu base registers UNIT_SIZE apart. | |
27 | * | |
28 | * There are usually many small percpu allocations many of them as | |
29 | * small as 4 bytes. The allocator organizes chunks into lists | |
30 | * according to free size and tries to allocate from the fullest one. | |
31 | * Each chunk keeps the maximum contiguous area size hint which is | |
32 | * guaranteed to be eqaul to or larger than the maximum contiguous | |
33 | * area in the chunk. This helps the allocator not to iterate the | |
34 | * chunk maps unnecessarily. | |
35 | * | |
36 | * Allocation state in each chunk is kept using an array of integers | |
37 | * on chunk->map. A positive value in the map represents a free | |
38 | * region and negative allocated. Allocation inside a chunk is done | |
39 | * by scanning this map sequentially and serving the first matching | |
40 | * entry. This is mostly copied from the percpu_modalloc() allocator. | |
41 | * Chunks are also linked into a rb tree to ease address to chunk | |
42 | * mapping during free. | |
43 | * | |
44 | * To use this allocator, arch code should do the followings. | |
45 | * | |
46 | * - define CONFIG_HAVE_DYNAMIC_PER_CPU_AREA | |
47 | * | |
48 | * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate | |
49 | * regular address to percpu pointer and back | |
50 | * | |
8d408b4b TH |
51 | * - use pcpu_setup_first_chunk() during percpu area initialization to |
52 | * setup the first chunk containing the kernel static percpu area | |
fbf59bc9 TH |
53 | */ |
54 | ||
55 | #include <linux/bitmap.h> | |
56 | #include <linux/bootmem.h> | |
57 | #include <linux/list.h> | |
58 | #include <linux/mm.h> | |
59 | #include <linux/module.h> | |
60 | #include <linux/mutex.h> | |
61 | #include <linux/percpu.h> | |
62 | #include <linux/pfn.h> | |
63 | #include <linux/rbtree.h> | |
64 | #include <linux/slab.h> | |
65 | #include <linux/vmalloc.h> | |
a56dbddf | 66 | #include <linux/workqueue.h> |
fbf59bc9 TH |
67 | |
68 | #include <asm/cacheflush.h> | |
69 | #include <asm/tlbflush.h> | |
70 | ||
fbf59bc9 TH |
71 | #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ |
72 | #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ | |
73 | ||
74 | struct pcpu_chunk { | |
75 | struct list_head list; /* linked to pcpu_slot lists */ | |
76 | struct rb_node rb_node; /* key is chunk->vm->addr */ | |
77 | int free_size; /* free bytes in the chunk */ | |
78 | int contig_hint; /* max contiguous size hint */ | |
79 | struct vm_struct *vm; /* mapped vmalloc region */ | |
80 | int map_used; /* # of map entries used */ | |
81 | int map_alloc; /* # of map entries allocated */ | |
82 | int *map; /* allocation map */ | |
8d408b4b | 83 | bool immutable; /* no [de]population allowed */ |
3e24aa58 TH |
84 | struct page **page; /* points to page array */ |
85 | struct page *page_ar[]; /* #cpus * UNIT_PAGES */ | |
fbf59bc9 TH |
86 | }; |
87 | ||
40150d37 TH |
88 | static int pcpu_unit_pages __read_mostly; |
89 | static int pcpu_unit_size __read_mostly; | |
90 | static int pcpu_chunk_size __read_mostly; | |
91 | static int pcpu_nr_slots __read_mostly; | |
92 | static size_t pcpu_chunk_struct_size __read_mostly; | |
fbf59bc9 TH |
93 | |
94 | /* the address of the first chunk which starts with the kernel static area */ | |
40150d37 | 95 | void *pcpu_base_addr __read_mostly; |
fbf59bc9 TH |
96 | EXPORT_SYMBOL_GPL(pcpu_base_addr); |
97 | ||
edcb4639 TH |
98 | /* optional reserved chunk, only accessible for reserved allocations */ |
99 | static struct pcpu_chunk *pcpu_reserved_chunk; | |
100 | /* offset limit of the reserved chunk */ | |
101 | static int pcpu_reserved_chunk_limit; | |
102 | ||
fbf59bc9 TH |
103 | /* |
104 | * One mutex to rule them all. | |
105 | * | |
106 | * The following mutex is grabbed in the outermost public alloc/free | |
107 | * interface functions and released only when the operation is | |
108 | * complete. As such, every function in this file other than the | |
109 | * outermost functions are called under pcpu_mutex. | |
110 | * | |
111 | * It can easily be switched to use spinlock such that only the area | |
112 | * allocation and page population commit are protected with it doing | |
113 | * actual [de]allocation without holding any lock. However, given | |
114 | * what this allocator does, I think it's better to let them run | |
115 | * sequentially. | |
116 | */ | |
117 | static DEFINE_MUTEX(pcpu_mutex); | |
118 | ||
40150d37 | 119 | static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ |
fbf59bc9 TH |
120 | static struct rb_root pcpu_addr_root = RB_ROOT; /* chunks by address */ |
121 | ||
a56dbddf TH |
122 | /* reclaim work to release fully free chunks, scheduled from free path */ |
123 | static void pcpu_reclaim(struct work_struct *work); | |
124 | static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); | |
125 | ||
d9b55eeb | 126 | static int __pcpu_size_to_slot(int size) |
fbf59bc9 | 127 | { |
cae3aeb8 | 128 | int highbit = fls(size); /* size is in bytes */ |
fbf59bc9 TH |
129 | return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); |
130 | } | |
131 | ||
d9b55eeb TH |
132 | static int pcpu_size_to_slot(int size) |
133 | { | |
134 | if (size == pcpu_unit_size) | |
135 | return pcpu_nr_slots - 1; | |
136 | return __pcpu_size_to_slot(size); | |
137 | } | |
138 | ||
fbf59bc9 TH |
139 | static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) |
140 | { | |
141 | if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) | |
142 | return 0; | |
143 | ||
144 | return pcpu_size_to_slot(chunk->free_size); | |
145 | } | |
146 | ||
147 | static int pcpu_page_idx(unsigned int cpu, int page_idx) | |
148 | { | |
d9b55eeb | 149 | return cpu * pcpu_unit_pages + page_idx; |
fbf59bc9 TH |
150 | } |
151 | ||
152 | static struct page **pcpu_chunk_pagep(struct pcpu_chunk *chunk, | |
153 | unsigned int cpu, int page_idx) | |
154 | { | |
155 | return &chunk->page[pcpu_page_idx(cpu, page_idx)]; | |
156 | } | |
157 | ||
158 | static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, | |
159 | unsigned int cpu, int page_idx) | |
160 | { | |
161 | return (unsigned long)chunk->vm->addr + | |
162 | (pcpu_page_idx(cpu, page_idx) << PAGE_SHIFT); | |
163 | } | |
164 | ||
165 | static bool pcpu_chunk_page_occupied(struct pcpu_chunk *chunk, | |
166 | int page_idx) | |
167 | { | |
168 | return *pcpu_chunk_pagep(chunk, 0, page_idx) != NULL; | |
169 | } | |
170 | ||
171 | /** | |
1880d93b TH |
172 | * pcpu_mem_alloc - allocate memory |
173 | * @size: bytes to allocate | |
fbf59bc9 | 174 | * |
1880d93b TH |
175 | * Allocate @size bytes. If @size is smaller than PAGE_SIZE, |
176 | * kzalloc() is used; otherwise, vmalloc() is used. The returned | |
177 | * memory is always zeroed. | |
fbf59bc9 TH |
178 | * |
179 | * RETURNS: | |
1880d93b | 180 | * Pointer to the allocated area on success, NULL on failure. |
fbf59bc9 | 181 | */ |
1880d93b | 182 | static void *pcpu_mem_alloc(size_t size) |
fbf59bc9 | 183 | { |
1880d93b TH |
184 | if (size <= PAGE_SIZE) |
185 | return kzalloc(size, GFP_KERNEL); | |
186 | else { | |
187 | void *ptr = vmalloc(size); | |
188 | if (ptr) | |
189 | memset(ptr, 0, size); | |
190 | return ptr; | |
191 | } | |
192 | } | |
fbf59bc9 | 193 | |
1880d93b TH |
194 | /** |
195 | * pcpu_mem_free - free memory | |
196 | * @ptr: memory to free | |
197 | * @size: size of the area | |
198 | * | |
199 | * Free @ptr. @ptr should have been allocated using pcpu_mem_alloc(). | |
200 | */ | |
201 | static void pcpu_mem_free(void *ptr, size_t size) | |
202 | { | |
fbf59bc9 | 203 | if (size <= PAGE_SIZE) |
1880d93b | 204 | kfree(ptr); |
fbf59bc9 | 205 | else |
1880d93b | 206 | vfree(ptr); |
fbf59bc9 TH |
207 | } |
208 | ||
209 | /** | |
210 | * pcpu_chunk_relocate - put chunk in the appropriate chunk slot | |
211 | * @chunk: chunk of interest | |
212 | * @oslot: the previous slot it was on | |
213 | * | |
214 | * This function is called after an allocation or free changed @chunk. | |
215 | * New slot according to the changed state is determined and @chunk is | |
edcb4639 TH |
216 | * moved to the slot. Note that the reserved chunk is never put on |
217 | * chunk slots. | |
fbf59bc9 TH |
218 | */ |
219 | static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) | |
220 | { | |
221 | int nslot = pcpu_chunk_slot(chunk); | |
222 | ||
edcb4639 | 223 | if (chunk != pcpu_reserved_chunk && oslot != nslot) { |
fbf59bc9 TH |
224 | if (oslot < nslot) |
225 | list_move(&chunk->list, &pcpu_slot[nslot]); | |
226 | else | |
227 | list_move_tail(&chunk->list, &pcpu_slot[nslot]); | |
228 | } | |
229 | } | |
230 | ||
231 | static struct rb_node **pcpu_chunk_rb_search(void *addr, | |
232 | struct rb_node **parentp) | |
233 | { | |
234 | struct rb_node **p = &pcpu_addr_root.rb_node; | |
235 | struct rb_node *parent = NULL; | |
236 | struct pcpu_chunk *chunk; | |
237 | ||
238 | while (*p) { | |
239 | parent = *p; | |
240 | chunk = rb_entry(parent, struct pcpu_chunk, rb_node); | |
241 | ||
242 | if (addr < chunk->vm->addr) | |
243 | p = &(*p)->rb_left; | |
244 | else if (addr > chunk->vm->addr) | |
245 | p = &(*p)->rb_right; | |
246 | else | |
247 | break; | |
248 | } | |
249 | ||
250 | if (parentp) | |
251 | *parentp = parent; | |
252 | return p; | |
253 | } | |
254 | ||
255 | /** | |
256 | * pcpu_chunk_addr_search - search for chunk containing specified address | |
257 | * @addr: address to search for | |
258 | * | |
259 | * Look for chunk which might contain @addr. More specifically, it | |
260 | * searchs for the chunk with the highest start address which isn't | |
261 | * beyond @addr. | |
262 | * | |
263 | * RETURNS: | |
264 | * The address of the found chunk. | |
265 | */ | |
266 | static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) | |
267 | { | |
268 | struct rb_node *n, *parent; | |
269 | struct pcpu_chunk *chunk; | |
270 | ||
edcb4639 TH |
271 | /* is it in the reserved chunk? */ |
272 | if (pcpu_reserved_chunk) { | |
273 | void *start = pcpu_reserved_chunk->vm->addr; | |
274 | ||
275 | if (addr >= start && addr < start + pcpu_reserved_chunk_limit) | |
276 | return pcpu_reserved_chunk; | |
277 | } | |
278 | ||
279 | /* nah... search the regular ones */ | |
fbf59bc9 TH |
280 | n = *pcpu_chunk_rb_search(addr, &parent); |
281 | if (!n) { | |
282 | /* no exactly matching chunk, the parent is the closest */ | |
283 | n = parent; | |
284 | BUG_ON(!n); | |
285 | } | |
286 | chunk = rb_entry(n, struct pcpu_chunk, rb_node); | |
287 | ||
288 | if (addr < chunk->vm->addr) { | |
289 | /* the parent was the next one, look for the previous one */ | |
290 | n = rb_prev(n); | |
291 | BUG_ON(!n); | |
292 | chunk = rb_entry(n, struct pcpu_chunk, rb_node); | |
293 | } | |
294 | ||
295 | return chunk; | |
296 | } | |
297 | ||
298 | /** | |
299 | * pcpu_chunk_addr_insert - insert chunk into address rb tree | |
300 | * @new: chunk to insert | |
301 | * | |
302 | * Insert @new into address rb tree. | |
303 | */ | |
304 | static void pcpu_chunk_addr_insert(struct pcpu_chunk *new) | |
305 | { | |
306 | struct rb_node **p, *parent; | |
307 | ||
308 | p = pcpu_chunk_rb_search(new->vm->addr, &parent); | |
309 | BUG_ON(*p); | |
310 | rb_link_node(&new->rb_node, parent, p); | |
311 | rb_insert_color(&new->rb_node, &pcpu_addr_root); | |
312 | } | |
313 | ||
9f7dcf22 TH |
314 | /** |
315 | * pcpu_extend_area_map - extend area map for allocation | |
316 | * @chunk: target chunk | |
317 | * | |
318 | * Extend area map of @chunk so that it can accomodate an allocation. | |
319 | * A single allocation can split an area into three areas, so this | |
320 | * function makes sure that @chunk->map has at least two extra slots. | |
321 | * | |
322 | * RETURNS: | |
323 | * 0 if noop, 1 if successfully extended, -errno on failure. | |
324 | */ | |
325 | static int pcpu_extend_area_map(struct pcpu_chunk *chunk) | |
326 | { | |
327 | int new_alloc; | |
328 | int *new; | |
329 | size_t size; | |
330 | ||
331 | /* has enough? */ | |
332 | if (chunk->map_alloc >= chunk->map_used + 2) | |
333 | return 0; | |
334 | ||
335 | new_alloc = PCPU_DFL_MAP_ALLOC; | |
336 | while (new_alloc < chunk->map_used + 2) | |
337 | new_alloc *= 2; | |
338 | ||
339 | new = pcpu_mem_alloc(new_alloc * sizeof(new[0])); | |
340 | if (!new) | |
341 | return -ENOMEM; | |
342 | ||
343 | size = chunk->map_alloc * sizeof(chunk->map[0]); | |
344 | memcpy(new, chunk->map, size); | |
345 | ||
346 | /* | |
347 | * map_alloc < PCPU_DFL_MAP_ALLOC indicates that the chunk is | |
348 | * one of the first chunks and still using static map. | |
349 | */ | |
350 | if (chunk->map_alloc >= PCPU_DFL_MAP_ALLOC) | |
351 | pcpu_mem_free(chunk->map, size); | |
352 | ||
353 | chunk->map_alloc = new_alloc; | |
354 | chunk->map = new; | |
355 | return 0; | |
356 | } | |
357 | ||
fbf59bc9 TH |
358 | /** |
359 | * pcpu_split_block - split a map block | |
360 | * @chunk: chunk of interest | |
361 | * @i: index of map block to split | |
cae3aeb8 TH |
362 | * @head: head size in bytes (can be 0) |
363 | * @tail: tail size in bytes (can be 0) | |
fbf59bc9 TH |
364 | * |
365 | * Split the @i'th map block into two or three blocks. If @head is | |
366 | * non-zero, @head bytes block is inserted before block @i moving it | |
367 | * to @i+1 and reducing its size by @head bytes. | |
368 | * | |
369 | * If @tail is non-zero, the target block, which can be @i or @i+1 | |
370 | * depending on @head, is reduced by @tail bytes and @tail byte block | |
371 | * is inserted after the target block. | |
372 | * | |
9f7dcf22 | 373 | * @chunk->map must have enough free slots to accomodate the split. |
fbf59bc9 | 374 | */ |
9f7dcf22 TH |
375 | static void pcpu_split_block(struct pcpu_chunk *chunk, int i, |
376 | int head, int tail) | |
fbf59bc9 TH |
377 | { |
378 | int nr_extra = !!head + !!tail; | |
1880d93b | 379 | |
9f7dcf22 | 380 | BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra); |
fbf59bc9 | 381 | |
9f7dcf22 | 382 | /* insert new subblocks */ |
fbf59bc9 TH |
383 | memmove(&chunk->map[i + nr_extra], &chunk->map[i], |
384 | sizeof(chunk->map[0]) * (chunk->map_used - i)); | |
385 | chunk->map_used += nr_extra; | |
386 | ||
387 | if (head) { | |
388 | chunk->map[i + 1] = chunk->map[i] - head; | |
389 | chunk->map[i++] = head; | |
390 | } | |
391 | if (tail) { | |
392 | chunk->map[i++] -= tail; | |
393 | chunk->map[i] = tail; | |
394 | } | |
fbf59bc9 TH |
395 | } |
396 | ||
397 | /** | |
398 | * pcpu_alloc_area - allocate area from a pcpu_chunk | |
399 | * @chunk: chunk of interest | |
cae3aeb8 | 400 | * @size: wanted size in bytes |
fbf59bc9 TH |
401 | * @align: wanted align |
402 | * | |
403 | * Try to allocate @size bytes area aligned at @align from @chunk. | |
404 | * Note that this function only allocates the offset. It doesn't | |
405 | * populate or map the area. | |
406 | * | |
9f7dcf22 TH |
407 | * @chunk->map must have at least two free slots. |
408 | * | |
fbf59bc9 | 409 | * RETURNS: |
9f7dcf22 TH |
410 | * Allocated offset in @chunk on success, -1 if no matching area is |
411 | * found. | |
fbf59bc9 TH |
412 | */ |
413 | static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align) | |
414 | { | |
415 | int oslot = pcpu_chunk_slot(chunk); | |
416 | int max_contig = 0; | |
417 | int i, off; | |
418 | ||
fbf59bc9 TH |
419 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) { |
420 | bool is_last = i + 1 == chunk->map_used; | |
421 | int head, tail; | |
422 | ||
423 | /* extra for alignment requirement */ | |
424 | head = ALIGN(off, align) - off; | |
425 | BUG_ON(i == 0 && head != 0); | |
426 | ||
427 | if (chunk->map[i] < 0) | |
428 | continue; | |
429 | if (chunk->map[i] < head + size) { | |
430 | max_contig = max(chunk->map[i], max_contig); | |
431 | continue; | |
432 | } | |
433 | ||
434 | /* | |
435 | * If head is small or the previous block is free, | |
436 | * merge'em. Note that 'small' is defined as smaller | |
437 | * than sizeof(int), which is very small but isn't too | |
438 | * uncommon for percpu allocations. | |
439 | */ | |
440 | if (head && (head < sizeof(int) || chunk->map[i - 1] > 0)) { | |
441 | if (chunk->map[i - 1] > 0) | |
442 | chunk->map[i - 1] += head; | |
443 | else { | |
444 | chunk->map[i - 1] -= head; | |
445 | chunk->free_size -= head; | |
446 | } | |
447 | chunk->map[i] -= head; | |
448 | off += head; | |
449 | head = 0; | |
450 | } | |
451 | ||
452 | /* if tail is small, just keep it around */ | |
453 | tail = chunk->map[i] - head - size; | |
454 | if (tail < sizeof(int)) | |
455 | tail = 0; | |
456 | ||
457 | /* split if warranted */ | |
458 | if (head || tail) { | |
9f7dcf22 | 459 | pcpu_split_block(chunk, i, head, tail); |
fbf59bc9 TH |
460 | if (head) { |
461 | i++; | |
462 | off += head; | |
463 | max_contig = max(chunk->map[i - 1], max_contig); | |
464 | } | |
465 | if (tail) | |
466 | max_contig = max(chunk->map[i + 1], max_contig); | |
467 | } | |
468 | ||
469 | /* update hint and mark allocated */ | |
470 | if (is_last) | |
471 | chunk->contig_hint = max_contig; /* fully scanned */ | |
472 | else | |
473 | chunk->contig_hint = max(chunk->contig_hint, | |
474 | max_contig); | |
475 | ||
476 | chunk->free_size -= chunk->map[i]; | |
477 | chunk->map[i] = -chunk->map[i]; | |
478 | ||
479 | pcpu_chunk_relocate(chunk, oslot); | |
480 | return off; | |
481 | } | |
482 | ||
483 | chunk->contig_hint = max_contig; /* fully scanned */ | |
484 | pcpu_chunk_relocate(chunk, oslot); | |
485 | ||
9f7dcf22 TH |
486 | /* tell the upper layer that this chunk has no matching area */ |
487 | return -1; | |
fbf59bc9 TH |
488 | } |
489 | ||
490 | /** | |
491 | * pcpu_free_area - free area to a pcpu_chunk | |
492 | * @chunk: chunk of interest | |
493 | * @freeme: offset of area to free | |
494 | * | |
495 | * Free area starting from @freeme to @chunk. Note that this function | |
496 | * only modifies the allocation map. It doesn't depopulate or unmap | |
497 | * the area. | |
498 | */ | |
499 | static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme) | |
500 | { | |
501 | int oslot = pcpu_chunk_slot(chunk); | |
502 | int i, off; | |
503 | ||
504 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) | |
505 | if (off == freeme) | |
506 | break; | |
507 | BUG_ON(off != freeme); | |
508 | BUG_ON(chunk->map[i] > 0); | |
509 | ||
510 | chunk->map[i] = -chunk->map[i]; | |
511 | chunk->free_size += chunk->map[i]; | |
512 | ||
513 | /* merge with previous? */ | |
514 | if (i > 0 && chunk->map[i - 1] >= 0) { | |
515 | chunk->map[i - 1] += chunk->map[i]; | |
516 | chunk->map_used--; | |
517 | memmove(&chunk->map[i], &chunk->map[i + 1], | |
518 | (chunk->map_used - i) * sizeof(chunk->map[0])); | |
519 | i--; | |
520 | } | |
521 | /* merge with next? */ | |
522 | if (i + 1 < chunk->map_used && chunk->map[i + 1] >= 0) { | |
523 | chunk->map[i] += chunk->map[i + 1]; | |
524 | chunk->map_used--; | |
525 | memmove(&chunk->map[i + 1], &chunk->map[i + 2], | |
526 | (chunk->map_used - (i + 1)) * sizeof(chunk->map[0])); | |
527 | } | |
528 | ||
529 | chunk->contig_hint = max(chunk->map[i], chunk->contig_hint); | |
530 | pcpu_chunk_relocate(chunk, oslot); | |
531 | } | |
532 | ||
533 | /** | |
534 | * pcpu_unmap - unmap pages out of a pcpu_chunk | |
535 | * @chunk: chunk of interest | |
536 | * @page_start: page index of the first page to unmap | |
537 | * @page_end: page index of the last page to unmap + 1 | |
538 | * @flush: whether to flush cache and tlb or not | |
539 | * | |
540 | * For each cpu, unmap pages [@page_start,@page_end) out of @chunk. | |
541 | * If @flush is true, vcache is flushed before unmapping and tlb | |
542 | * after. | |
543 | */ | |
544 | static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end, | |
545 | bool flush) | |
546 | { | |
547 | unsigned int last = num_possible_cpus() - 1; | |
548 | unsigned int cpu; | |
549 | ||
8d408b4b TH |
550 | /* unmap must not be done on immutable chunk */ |
551 | WARN_ON(chunk->immutable); | |
552 | ||
fbf59bc9 TH |
553 | /* |
554 | * Each flushing trial can be very expensive, issue flush on | |
555 | * the whole region at once rather than doing it for each cpu. | |
556 | * This could be an overkill but is more scalable. | |
557 | */ | |
558 | if (flush) | |
559 | flush_cache_vunmap(pcpu_chunk_addr(chunk, 0, page_start), | |
560 | pcpu_chunk_addr(chunk, last, page_end)); | |
561 | ||
562 | for_each_possible_cpu(cpu) | |
563 | unmap_kernel_range_noflush( | |
564 | pcpu_chunk_addr(chunk, cpu, page_start), | |
565 | (page_end - page_start) << PAGE_SHIFT); | |
566 | ||
567 | /* ditto as flush_cache_vunmap() */ | |
568 | if (flush) | |
569 | flush_tlb_kernel_range(pcpu_chunk_addr(chunk, 0, page_start), | |
570 | pcpu_chunk_addr(chunk, last, page_end)); | |
571 | } | |
572 | ||
573 | /** | |
574 | * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk | |
575 | * @chunk: chunk to depopulate | |
576 | * @off: offset to the area to depopulate | |
cae3aeb8 | 577 | * @size: size of the area to depopulate in bytes |
fbf59bc9 TH |
578 | * @flush: whether to flush cache and tlb or not |
579 | * | |
580 | * For each cpu, depopulate and unmap pages [@page_start,@page_end) | |
581 | * from @chunk. If @flush is true, vcache is flushed before unmapping | |
582 | * and tlb after. | |
583 | */ | |
cae3aeb8 TH |
584 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size, |
585 | bool flush) | |
fbf59bc9 TH |
586 | { |
587 | int page_start = PFN_DOWN(off); | |
588 | int page_end = PFN_UP(off + size); | |
589 | int unmap_start = -1; | |
590 | int uninitialized_var(unmap_end); | |
591 | unsigned int cpu; | |
592 | int i; | |
593 | ||
594 | for (i = page_start; i < page_end; i++) { | |
595 | for_each_possible_cpu(cpu) { | |
596 | struct page **pagep = pcpu_chunk_pagep(chunk, cpu, i); | |
597 | ||
598 | if (!*pagep) | |
599 | continue; | |
600 | ||
601 | __free_page(*pagep); | |
602 | ||
603 | /* | |
604 | * If it's partial depopulation, it might get | |
605 | * populated or depopulated again. Mark the | |
606 | * page gone. | |
607 | */ | |
608 | *pagep = NULL; | |
609 | ||
610 | unmap_start = unmap_start < 0 ? i : unmap_start; | |
611 | unmap_end = i + 1; | |
612 | } | |
613 | } | |
614 | ||
615 | if (unmap_start >= 0) | |
616 | pcpu_unmap(chunk, unmap_start, unmap_end, flush); | |
617 | } | |
618 | ||
619 | /** | |
620 | * pcpu_map - map pages into a pcpu_chunk | |
621 | * @chunk: chunk of interest | |
622 | * @page_start: page index of the first page to map | |
623 | * @page_end: page index of the last page to map + 1 | |
624 | * | |
625 | * For each cpu, map pages [@page_start,@page_end) into @chunk. | |
626 | * vcache is flushed afterwards. | |
627 | */ | |
628 | static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end) | |
629 | { | |
630 | unsigned int last = num_possible_cpus() - 1; | |
631 | unsigned int cpu; | |
632 | int err; | |
633 | ||
8d408b4b TH |
634 | /* map must not be done on immutable chunk */ |
635 | WARN_ON(chunk->immutable); | |
636 | ||
fbf59bc9 TH |
637 | for_each_possible_cpu(cpu) { |
638 | err = map_kernel_range_noflush( | |
639 | pcpu_chunk_addr(chunk, cpu, page_start), | |
640 | (page_end - page_start) << PAGE_SHIFT, | |
641 | PAGE_KERNEL, | |
642 | pcpu_chunk_pagep(chunk, cpu, page_start)); | |
643 | if (err < 0) | |
644 | return err; | |
645 | } | |
646 | ||
647 | /* flush at once, please read comments in pcpu_unmap() */ | |
648 | flush_cache_vmap(pcpu_chunk_addr(chunk, 0, page_start), | |
649 | pcpu_chunk_addr(chunk, last, page_end)); | |
650 | return 0; | |
651 | } | |
652 | ||
653 | /** | |
654 | * pcpu_populate_chunk - populate and map an area of a pcpu_chunk | |
655 | * @chunk: chunk of interest | |
656 | * @off: offset to the area to populate | |
cae3aeb8 | 657 | * @size: size of the area to populate in bytes |
fbf59bc9 TH |
658 | * |
659 | * For each cpu, populate and map pages [@page_start,@page_end) into | |
660 | * @chunk. The area is cleared on return. | |
661 | */ | |
662 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size) | |
663 | { | |
664 | const gfp_t alloc_mask = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD; | |
665 | int page_start = PFN_DOWN(off); | |
666 | int page_end = PFN_UP(off + size); | |
667 | int map_start = -1; | |
02d51fdf | 668 | int uninitialized_var(map_end); |
fbf59bc9 TH |
669 | unsigned int cpu; |
670 | int i; | |
671 | ||
672 | for (i = page_start; i < page_end; i++) { | |
673 | if (pcpu_chunk_page_occupied(chunk, i)) { | |
674 | if (map_start >= 0) { | |
675 | if (pcpu_map(chunk, map_start, map_end)) | |
676 | goto err; | |
677 | map_start = -1; | |
678 | } | |
679 | continue; | |
680 | } | |
681 | ||
682 | map_start = map_start < 0 ? i : map_start; | |
683 | map_end = i + 1; | |
684 | ||
685 | for_each_possible_cpu(cpu) { | |
686 | struct page **pagep = pcpu_chunk_pagep(chunk, cpu, i); | |
687 | ||
688 | *pagep = alloc_pages_node(cpu_to_node(cpu), | |
689 | alloc_mask, 0); | |
690 | if (!*pagep) | |
691 | goto err; | |
692 | } | |
693 | } | |
694 | ||
695 | if (map_start >= 0 && pcpu_map(chunk, map_start, map_end)) | |
696 | goto err; | |
697 | ||
698 | for_each_possible_cpu(cpu) | |
d9b55eeb | 699 | memset(chunk->vm->addr + cpu * pcpu_unit_size + off, 0, |
fbf59bc9 TH |
700 | size); |
701 | ||
702 | return 0; | |
703 | err: | |
704 | /* likely under heavy memory pressure, give memory back */ | |
705 | pcpu_depopulate_chunk(chunk, off, size, true); | |
706 | return -ENOMEM; | |
707 | } | |
708 | ||
709 | static void free_pcpu_chunk(struct pcpu_chunk *chunk) | |
710 | { | |
711 | if (!chunk) | |
712 | return; | |
713 | if (chunk->vm) | |
714 | free_vm_area(chunk->vm); | |
1880d93b | 715 | pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0])); |
fbf59bc9 TH |
716 | kfree(chunk); |
717 | } | |
718 | ||
719 | static struct pcpu_chunk *alloc_pcpu_chunk(void) | |
720 | { | |
721 | struct pcpu_chunk *chunk; | |
722 | ||
723 | chunk = kzalloc(pcpu_chunk_struct_size, GFP_KERNEL); | |
724 | if (!chunk) | |
725 | return NULL; | |
726 | ||
1880d93b | 727 | chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0])); |
fbf59bc9 TH |
728 | chunk->map_alloc = PCPU_DFL_MAP_ALLOC; |
729 | chunk->map[chunk->map_used++] = pcpu_unit_size; | |
3e24aa58 | 730 | chunk->page = chunk->page_ar; |
fbf59bc9 TH |
731 | |
732 | chunk->vm = get_vm_area(pcpu_chunk_size, GFP_KERNEL); | |
733 | if (!chunk->vm) { | |
734 | free_pcpu_chunk(chunk); | |
735 | return NULL; | |
736 | } | |
737 | ||
738 | INIT_LIST_HEAD(&chunk->list); | |
739 | chunk->free_size = pcpu_unit_size; | |
740 | chunk->contig_hint = pcpu_unit_size; | |
741 | ||
742 | return chunk; | |
743 | } | |
744 | ||
745 | /** | |
edcb4639 | 746 | * pcpu_alloc - the percpu allocator |
cae3aeb8 | 747 | * @size: size of area to allocate in bytes |
fbf59bc9 | 748 | * @align: alignment of area (max PAGE_SIZE) |
edcb4639 | 749 | * @reserved: allocate from the reserved chunk if available |
fbf59bc9 TH |
750 | * |
751 | * Allocate percpu area of @size bytes aligned at @align. Might | |
752 | * sleep. Might trigger writeouts. | |
753 | * | |
754 | * RETURNS: | |
755 | * Percpu pointer to the allocated area on success, NULL on failure. | |
756 | */ | |
edcb4639 | 757 | static void *pcpu_alloc(size_t size, size_t align, bool reserved) |
fbf59bc9 TH |
758 | { |
759 | void *ptr = NULL; | |
760 | struct pcpu_chunk *chunk; | |
761 | int slot, off; | |
762 | ||
8d408b4b | 763 | if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { |
fbf59bc9 TH |
764 | WARN(true, "illegal size (%zu) or align (%zu) for " |
765 | "percpu allocation\n", size, align); | |
766 | return NULL; | |
767 | } | |
768 | ||
769 | mutex_lock(&pcpu_mutex); | |
770 | ||
edcb4639 TH |
771 | /* serve reserved allocations from the reserved chunk if available */ |
772 | if (reserved && pcpu_reserved_chunk) { | |
773 | chunk = pcpu_reserved_chunk; | |
9f7dcf22 TH |
774 | if (size > chunk->contig_hint || |
775 | pcpu_extend_area_map(chunk) < 0) | |
edcb4639 TH |
776 | goto out_unlock; |
777 | off = pcpu_alloc_area(chunk, size, align); | |
778 | if (off >= 0) | |
779 | goto area_found; | |
780 | goto out_unlock; | |
781 | } | |
782 | ||
783 | /* search through normal chunks */ | |
fbf59bc9 TH |
784 | for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { |
785 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { | |
786 | if (size > chunk->contig_hint) | |
787 | continue; | |
9f7dcf22 TH |
788 | if (pcpu_extend_area_map(chunk) < 0) |
789 | goto out_unlock; | |
fbf59bc9 TH |
790 | off = pcpu_alloc_area(chunk, size, align); |
791 | if (off >= 0) | |
792 | goto area_found; | |
fbf59bc9 TH |
793 | } |
794 | } | |
795 | ||
796 | /* hmmm... no space left, create a new chunk */ | |
797 | chunk = alloc_pcpu_chunk(); | |
798 | if (!chunk) | |
799 | goto out_unlock; | |
800 | pcpu_chunk_relocate(chunk, -1); | |
801 | pcpu_chunk_addr_insert(chunk); | |
802 | ||
803 | off = pcpu_alloc_area(chunk, size, align); | |
804 | if (off < 0) | |
805 | goto out_unlock; | |
806 | ||
807 | area_found: | |
808 | /* populate, map and clear the area */ | |
809 | if (pcpu_populate_chunk(chunk, off, size)) { | |
810 | pcpu_free_area(chunk, off); | |
811 | goto out_unlock; | |
812 | } | |
813 | ||
814 | ptr = __addr_to_pcpu_ptr(chunk->vm->addr + off); | |
815 | out_unlock: | |
816 | mutex_unlock(&pcpu_mutex); | |
817 | return ptr; | |
818 | } | |
edcb4639 TH |
819 | |
820 | /** | |
821 | * __alloc_percpu - allocate dynamic percpu area | |
822 | * @size: size of area to allocate in bytes | |
823 | * @align: alignment of area (max PAGE_SIZE) | |
824 | * | |
825 | * Allocate percpu area of @size bytes aligned at @align. Might | |
826 | * sleep. Might trigger writeouts. | |
827 | * | |
828 | * RETURNS: | |
829 | * Percpu pointer to the allocated area on success, NULL on failure. | |
830 | */ | |
831 | void *__alloc_percpu(size_t size, size_t align) | |
832 | { | |
833 | return pcpu_alloc(size, align, false); | |
834 | } | |
fbf59bc9 TH |
835 | EXPORT_SYMBOL_GPL(__alloc_percpu); |
836 | ||
edcb4639 TH |
837 | /** |
838 | * __alloc_reserved_percpu - allocate reserved percpu area | |
839 | * @size: size of area to allocate in bytes | |
840 | * @align: alignment of area (max PAGE_SIZE) | |
841 | * | |
842 | * Allocate percpu area of @size bytes aligned at @align from reserved | |
843 | * percpu area if arch has set it up; otherwise, allocation is served | |
844 | * from the same dynamic area. Might sleep. Might trigger writeouts. | |
845 | * | |
846 | * RETURNS: | |
847 | * Percpu pointer to the allocated area on success, NULL on failure. | |
848 | */ | |
849 | void *__alloc_reserved_percpu(size_t size, size_t align) | |
850 | { | |
851 | return pcpu_alloc(size, align, true); | |
852 | } | |
853 | ||
a56dbddf TH |
854 | /** |
855 | * pcpu_reclaim - reclaim fully free chunks, workqueue function | |
856 | * @work: unused | |
857 | * | |
858 | * Reclaim all fully free chunks except for the first one. | |
859 | */ | |
860 | static void pcpu_reclaim(struct work_struct *work) | |
fbf59bc9 | 861 | { |
a56dbddf TH |
862 | LIST_HEAD(todo); |
863 | struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; | |
864 | struct pcpu_chunk *chunk, *next; | |
865 | ||
866 | mutex_lock(&pcpu_mutex); | |
867 | ||
868 | list_for_each_entry_safe(chunk, next, head, list) { | |
869 | WARN_ON(chunk->immutable); | |
870 | ||
871 | /* spare the first one */ | |
872 | if (chunk == list_first_entry(head, struct pcpu_chunk, list)) | |
873 | continue; | |
874 | ||
875 | rb_erase(&chunk->rb_node, &pcpu_addr_root); | |
876 | list_move(&chunk->list, &todo); | |
877 | } | |
878 | ||
879 | mutex_unlock(&pcpu_mutex); | |
880 | ||
881 | list_for_each_entry_safe(chunk, next, &todo, list) { | |
882 | pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false); | |
883 | free_pcpu_chunk(chunk); | |
884 | } | |
fbf59bc9 TH |
885 | } |
886 | ||
887 | /** | |
888 | * free_percpu - free percpu area | |
889 | * @ptr: pointer to area to free | |
890 | * | |
891 | * Free percpu area @ptr. Might sleep. | |
892 | */ | |
893 | void free_percpu(void *ptr) | |
894 | { | |
895 | void *addr = __pcpu_ptr_to_addr(ptr); | |
896 | struct pcpu_chunk *chunk; | |
897 | int off; | |
898 | ||
899 | if (!ptr) | |
900 | return; | |
901 | ||
902 | mutex_lock(&pcpu_mutex); | |
903 | ||
904 | chunk = pcpu_chunk_addr_search(addr); | |
905 | off = addr - chunk->vm->addr; | |
906 | ||
907 | pcpu_free_area(chunk, off); | |
908 | ||
a56dbddf | 909 | /* if there are more than one fully free chunks, wake up grim reaper */ |
fbf59bc9 TH |
910 | if (chunk->free_size == pcpu_unit_size) { |
911 | struct pcpu_chunk *pos; | |
912 | ||
a56dbddf | 913 | list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) |
fbf59bc9 | 914 | if (pos != chunk) { |
a56dbddf | 915 | schedule_work(&pcpu_reclaim_work); |
fbf59bc9 TH |
916 | break; |
917 | } | |
918 | } | |
919 | ||
920 | mutex_unlock(&pcpu_mutex); | |
921 | } | |
922 | EXPORT_SYMBOL_GPL(free_percpu); | |
923 | ||
924 | /** | |
8d408b4b TH |
925 | * pcpu_setup_first_chunk - initialize the first percpu chunk |
926 | * @get_page_fn: callback to fetch page pointer | |
927 | * @static_size: the size of static percpu area in bytes | |
edcb4639 | 928 | * @reserved_size: the size of reserved percpu area in bytes |
cafe8816 TH |
929 | * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto |
930 | * @dyn_size: free size for dynamic allocation in bytes, -1 for auto | |
8d408b4b TH |
931 | * @base_addr: mapped address, NULL for auto |
932 | * @populate_pte_fn: callback to allocate pagetable, NULL if unnecessary | |
933 | * | |
934 | * Initialize the first percpu chunk which contains the kernel static | |
935 | * perpcu area. This function is to be called from arch percpu area | |
936 | * setup path. The first two parameters are mandatory. The rest are | |
937 | * optional. | |
938 | * | |
939 | * @get_page_fn() should return pointer to percpu page given cpu | |
940 | * number and page number. It should at least return enough pages to | |
941 | * cover the static area. The returned pages for static area should | |
942 | * have been initialized with valid data. If @unit_size is specified, | |
943 | * it can also return pages after the static area. NULL return | |
944 | * indicates end of pages for the cpu. Note that @get_page_fn() must | |
945 | * return the same number of pages for all cpus. | |
946 | * | |
edcb4639 TH |
947 | * @reserved_size, if non-zero, specifies the amount of bytes to |
948 | * reserve after the static area in the first chunk. This reserves | |
949 | * the first chunk such that it's available only through reserved | |
950 | * percpu allocation. This is primarily used to serve module percpu | |
951 | * static areas on architectures where the addressing model has | |
952 | * limited offset range for symbol relocations to guarantee module | |
953 | * percpu symbols fall inside the relocatable range. | |
954 | * | |
cafe8816 TH |
955 | * @unit_size, if non-negative, specifies unit size and must be |
956 | * aligned to PAGE_SIZE and equal to or larger than @static_size + | |
edcb4639 | 957 | * @reserved_size + @dyn_size. |
8d408b4b | 958 | * |
cafe8816 TH |
959 | * @dyn_size, if non-negative, limits the number of bytes available |
960 | * for dynamic allocation in the first chunk. Specifying non-negative | |
961 | * value make percpu leave alone the area beyond @static_size + | |
edcb4639 | 962 | * @reserved_size + @dyn_size. |
8d408b4b TH |
963 | * |
964 | * Non-null @base_addr means that the caller already allocated virtual | |
965 | * region for the first chunk and mapped it. percpu must not mess | |
966 | * with the chunk. Note that @base_addr with 0 @unit_size or non-NULL | |
967 | * @populate_pte_fn doesn't make any sense. | |
968 | * | |
969 | * @populate_pte_fn is used to populate the pagetable. NULL means the | |
970 | * caller already populated the pagetable. | |
fbf59bc9 | 971 | * |
edcb4639 TH |
972 | * If the first chunk ends up with both reserved and dynamic areas, it |
973 | * is served by two chunks - one to serve the core static and reserved | |
974 | * areas and the other for the dynamic area. They share the same vm | |
975 | * and page map but uses different area allocation map to stay away | |
976 | * from each other. The latter chunk is circulated in the chunk slots | |
977 | * and available for dynamic allocation like any other chunks. | |
978 | * | |
fbf59bc9 TH |
979 | * RETURNS: |
980 | * The determined pcpu_unit_size which can be used to initialize | |
981 | * percpu access. | |
982 | */ | |
8d408b4b | 983 | size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, |
edcb4639 | 984 | size_t static_size, size_t reserved_size, |
cafe8816 TH |
985 | ssize_t unit_size, ssize_t dyn_size, |
986 | void *base_addr, | |
8d408b4b | 987 | pcpu_populate_pte_fn_t populate_pte_fn) |
fbf59bc9 | 988 | { |
2441d15c | 989 | static struct vm_struct first_vm; |
edcb4639 TH |
990 | static int smap[2], dmap[2]; |
991 | struct pcpu_chunk *schunk, *dchunk = NULL; | |
fbf59bc9 | 992 | unsigned int cpu; |
8d408b4b | 993 | int nr_pages; |
fbf59bc9 TH |
994 | int err, i; |
995 | ||
8d408b4b | 996 | /* santiy checks */ |
edcb4639 TH |
997 | BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC || |
998 | ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC); | |
8d408b4b | 999 | BUG_ON(!static_size); |
cafe8816 | 1000 | if (unit_size >= 0) { |
edcb4639 | 1001 | BUG_ON(unit_size < static_size + reserved_size + |
cafe8816 TH |
1002 | (dyn_size >= 0 ? dyn_size : 0)); |
1003 | BUG_ON(unit_size & ~PAGE_MASK); | |
1004 | } else { | |
1005 | BUG_ON(dyn_size >= 0); | |
1006 | BUG_ON(base_addr); | |
1007 | } | |
8d408b4b | 1008 | BUG_ON(base_addr && populate_pte_fn); |
fbf59bc9 | 1009 | |
cafe8816 | 1010 | if (unit_size >= 0) |
8d408b4b TH |
1011 | pcpu_unit_pages = unit_size >> PAGE_SHIFT; |
1012 | else | |
1013 | pcpu_unit_pages = max_t(int, PCPU_MIN_UNIT_SIZE >> PAGE_SHIFT, | |
edcb4639 | 1014 | PFN_UP(static_size + reserved_size)); |
8d408b4b | 1015 | |
d9b55eeb | 1016 | pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; |
fbf59bc9 | 1017 | pcpu_chunk_size = num_possible_cpus() * pcpu_unit_size; |
fbf59bc9 | 1018 | pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) |
cb83b42e | 1019 | + num_possible_cpus() * pcpu_unit_pages * sizeof(struct page *); |
fbf59bc9 | 1020 | |
cafe8816 | 1021 | if (dyn_size < 0) |
edcb4639 | 1022 | dyn_size = pcpu_unit_size - static_size - reserved_size; |
cafe8816 | 1023 | |
d9b55eeb TH |
1024 | /* |
1025 | * Allocate chunk slots. The additional last slot is for | |
1026 | * empty chunks. | |
1027 | */ | |
1028 | pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; | |
fbf59bc9 TH |
1029 | pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0])); |
1030 | for (i = 0; i < pcpu_nr_slots; i++) | |
1031 | INIT_LIST_HEAD(&pcpu_slot[i]); | |
1032 | ||
edcb4639 TH |
1033 | /* |
1034 | * Initialize static chunk. If reserved_size is zero, the | |
1035 | * static chunk covers static area + dynamic allocation area | |
1036 | * in the first chunk. If reserved_size is not zero, it | |
1037 | * covers static area + reserved area (mostly used for module | |
1038 | * static percpu allocation). | |
1039 | */ | |
2441d15c TH |
1040 | schunk = alloc_bootmem(pcpu_chunk_struct_size); |
1041 | INIT_LIST_HEAD(&schunk->list); | |
1042 | schunk->vm = &first_vm; | |
61ace7fa TH |
1043 | schunk->map = smap; |
1044 | schunk->map_alloc = ARRAY_SIZE(smap); | |
3e24aa58 | 1045 | schunk->page = schunk->page_ar; |
edcb4639 TH |
1046 | |
1047 | if (reserved_size) { | |
1048 | schunk->free_size = reserved_size; | |
1049 | pcpu_reserved_chunk = schunk; /* not for dynamic alloc */ | |
1050 | } else { | |
1051 | schunk->free_size = dyn_size; | |
1052 | dyn_size = 0; /* dynamic area covered */ | |
1053 | } | |
2441d15c | 1054 | schunk->contig_hint = schunk->free_size; |
fbf59bc9 | 1055 | |
61ace7fa TH |
1056 | schunk->map[schunk->map_used++] = -static_size; |
1057 | if (schunk->free_size) | |
1058 | schunk->map[schunk->map_used++] = schunk->free_size; | |
1059 | ||
edcb4639 TH |
1060 | pcpu_reserved_chunk_limit = static_size + schunk->free_size; |
1061 | ||
1062 | /* init dynamic chunk if necessary */ | |
1063 | if (dyn_size) { | |
1064 | dchunk = alloc_bootmem(sizeof(struct pcpu_chunk)); | |
1065 | INIT_LIST_HEAD(&dchunk->list); | |
1066 | dchunk->vm = &first_vm; | |
1067 | dchunk->map = dmap; | |
1068 | dchunk->map_alloc = ARRAY_SIZE(dmap); | |
1069 | dchunk->page = schunk->page_ar; /* share page map with schunk */ | |
1070 | ||
1071 | dchunk->contig_hint = dchunk->free_size = dyn_size; | |
1072 | dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit; | |
1073 | dchunk->map[dchunk->map_used++] = dchunk->free_size; | |
1074 | } | |
1075 | ||
8d408b4b | 1076 | /* allocate vm address */ |
2441d15c TH |
1077 | first_vm.flags = VM_ALLOC; |
1078 | first_vm.size = pcpu_chunk_size; | |
8d408b4b TH |
1079 | |
1080 | if (!base_addr) | |
2441d15c | 1081 | vm_area_register_early(&first_vm, PAGE_SIZE); |
8d408b4b TH |
1082 | else { |
1083 | /* | |
1084 | * Pages already mapped. No need to remap into | |
edcb4639 TH |
1085 | * vmalloc area. In this case the first chunks can't |
1086 | * be mapped or unmapped by percpu and are marked | |
8d408b4b TH |
1087 | * immutable. |
1088 | */ | |
2441d15c TH |
1089 | first_vm.addr = base_addr; |
1090 | schunk->immutable = true; | |
edcb4639 TH |
1091 | if (dchunk) |
1092 | dchunk->immutable = true; | |
8d408b4b TH |
1093 | } |
1094 | ||
1095 | /* assign pages */ | |
1096 | nr_pages = -1; | |
fbf59bc9 | 1097 | for_each_possible_cpu(cpu) { |
8d408b4b TH |
1098 | for (i = 0; i < pcpu_unit_pages; i++) { |
1099 | struct page *page = get_page_fn(cpu, i); | |
1100 | ||
1101 | if (!page) | |
1102 | break; | |
2441d15c | 1103 | *pcpu_chunk_pagep(schunk, cpu, i) = page; |
fbf59bc9 | 1104 | } |
8d408b4b | 1105 | |
61ace7fa | 1106 | BUG_ON(i < PFN_UP(static_size)); |
8d408b4b TH |
1107 | |
1108 | if (nr_pages < 0) | |
1109 | nr_pages = i; | |
1110 | else | |
1111 | BUG_ON(nr_pages != i); | |
fbf59bc9 TH |
1112 | } |
1113 | ||
8d408b4b TH |
1114 | /* map them */ |
1115 | if (populate_pte_fn) { | |
1116 | for_each_possible_cpu(cpu) | |
1117 | for (i = 0; i < nr_pages; i++) | |
2441d15c | 1118 | populate_pte_fn(pcpu_chunk_addr(schunk, |
8d408b4b TH |
1119 | cpu, i)); |
1120 | ||
2441d15c | 1121 | err = pcpu_map(schunk, 0, nr_pages); |
8d408b4b TH |
1122 | if (err) |
1123 | panic("failed to setup static percpu area, err=%d\n", | |
1124 | err); | |
1125 | } | |
fbf59bc9 | 1126 | |
2441d15c | 1127 | /* link the first chunk in */ |
edcb4639 TH |
1128 | if (!dchunk) { |
1129 | pcpu_chunk_relocate(schunk, -1); | |
1130 | pcpu_chunk_addr_insert(schunk); | |
1131 | } else { | |
1132 | pcpu_chunk_relocate(dchunk, -1); | |
1133 | pcpu_chunk_addr_insert(dchunk); | |
1134 | } | |
fbf59bc9 TH |
1135 | |
1136 | /* we're done */ | |
2441d15c | 1137 | pcpu_base_addr = (void *)pcpu_chunk_addr(schunk, 0, 0); |
fbf59bc9 TH |
1138 | return pcpu_unit_size; |
1139 | } |