Commit | Line | Data |
---|---|---|
fbf59bc9 | 1 | /* |
88999a89 | 2 | * mm/percpu.c - percpu memory allocator |
fbf59bc9 TH |
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 | |
88999a89 TH |
10 | * areas. Percpu areas are allocated in chunks. Each chunk is |
11 | * consisted of boot-time determined number of units and the first | |
12 | * chunk is used for static percpu variables in the kernel image | |
2f39e637 TH |
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. | |
88999a89 | 16 | * When a chunk is filled up, another chunk is allocated. |
fbf59bc9 TH |
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, | |
2f39e637 TH |
25 | * c1:u1, c1:u2 and c1:u3. On UMA, units corresponds directly to |
26 | * cpus. On NUMA, the mapping can be non-linear and even sparse. | |
27 | * Percpu access can be done by configuring percpu base registers | |
28 | * according to cpu to unit mapping and pcpu_unit_size. | |
fbf59bc9 | 29 | * |
2f39e637 TH |
30 | * There are usually many small percpu allocations many of them being |
31 | * as small as 4 bytes. The allocator organizes chunks into lists | |
fbf59bc9 TH |
32 | * according to free size and tries to allocate from the fullest one. |
33 | * Each chunk keeps the maximum contiguous area size hint which is | |
4785879e | 34 | * guaranteed to be equal to or larger than the maximum contiguous |
fbf59bc9 TH |
35 | * area in the chunk. This helps the allocator not to iterate the |
36 | * chunk maps unnecessarily. | |
37 | * | |
38 | * Allocation state in each chunk is kept using an array of integers | |
39 | * on chunk->map. A positive value in the map represents a free | |
40 | * region and negative allocated. Allocation inside a chunk is done | |
41 | * by scanning this map sequentially and serving the first matching | |
42 | * entry. This is mostly copied from the percpu_modalloc() allocator. | |
e1b9aa3f CL |
43 | * Chunks can be determined from the address using the index field |
44 | * in the page struct. The index field contains a pointer to the chunk. | |
fbf59bc9 TH |
45 | * |
46 | * To use this allocator, arch code should do the followings. | |
47 | * | |
fbf59bc9 | 48 | * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate |
e0100983 TH |
49 | * regular address to percpu pointer and back if they need to be |
50 | * different from the default | |
fbf59bc9 | 51 | * |
8d408b4b TH |
52 | * - use pcpu_setup_first_chunk() during percpu area initialization to |
53 | * setup the first chunk containing the kernel static percpu area | |
fbf59bc9 TH |
54 | */ |
55 | ||
56 | #include <linux/bitmap.h> | |
57 | #include <linux/bootmem.h> | |
fd1e8a1f | 58 | #include <linux/err.h> |
fbf59bc9 | 59 | #include <linux/list.h> |
a530b795 | 60 | #include <linux/log2.h> |
fbf59bc9 TH |
61 | #include <linux/mm.h> |
62 | #include <linux/module.h> | |
63 | #include <linux/mutex.h> | |
64 | #include <linux/percpu.h> | |
65 | #include <linux/pfn.h> | |
fbf59bc9 | 66 | #include <linux/slab.h> |
ccea34b5 | 67 | #include <linux/spinlock.h> |
fbf59bc9 | 68 | #include <linux/vmalloc.h> |
a56dbddf | 69 | #include <linux/workqueue.h> |
f528f0b8 | 70 | #include <linux/kmemleak.h> |
fbf59bc9 TH |
71 | |
72 | #include <asm/cacheflush.h> | |
e0100983 | 73 | #include <asm/sections.h> |
fbf59bc9 | 74 | #include <asm/tlbflush.h> |
3b034b0d | 75 | #include <asm/io.h> |
fbf59bc9 | 76 | |
fbf59bc9 TH |
77 | #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ |
78 | #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ | |
79 | ||
bbddff05 | 80 | #ifdef CONFIG_SMP |
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) \ | |
43cf38eb TH |
84 | (void __percpu *)((unsigned long)(addr) - \ |
85 | (unsigned long)pcpu_base_addr + \ | |
86 | (unsigned long)__per_cpu_start) | |
e0100983 TH |
87 | #endif |
88 | #ifndef __pcpu_ptr_to_addr | |
89 | #define __pcpu_ptr_to_addr(ptr) \ | |
43cf38eb TH |
90 | (void __force *)((unsigned long)(ptr) + \ |
91 | (unsigned long)pcpu_base_addr - \ | |
92 | (unsigned long)__per_cpu_start) | |
e0100983 | 93 | #endif |
bbddff05 TH |
94 | #else /* CONFIG_SMP */ |
95 | /* on UP, it's always identity mapped */ | |
96 | #define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr) | |
97 | #define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr) | |
98 | #endif /* CONFIG_SMP */ | |
e0100983 | 99 | |
fbf59bc9 TH |
100 | struct pcpu_chunk { |
101 | struct list_head list; /* linked to pcpu_slot lists */ | |
fbf59bc9 TH |
102 | int free_size; /* free bytes in the chunk */ |
103 | int contig_hint; /* max contiguous size hint */ | |
bba174f5 | 104 | void *base_addr; /* base address of this chunk */ |
723ad1d9 | 105 | int map_used; /* # of map entries used before the sentry */ |
fbf59bc9 TH |
106 | int map_alloc; /* # of map entries allocated */ |
107 | int *map; /* allocation map */ | |
88999a89 | 108 | void *data; /* chunk data */ |
3d331ad7 | 109 | int first_free; /* no free below this */ |
8d408b4b | 110 | bool immutable; /* no [de]population allowed */ |
ce3141a2 | 111 | unsigned long populated[]; /* populated bitmap */ |
fbf59bc9 TH |
112 | }; |
113 | ||
40150d37 TH |
114 | static int pcpu_unit_pages __read_mostly; |
115 | static int pcpu_unit_size __read_mostly; | |
2f39e637 | 116 | static int pcpu_nr_units __read_mostly; |
6563297c | 117 | static int pcpu_atom_size __read_mostly; |
40150d37 TH |
118 | static int pcpu_nr_slots __read_mostly; |
119 | static size_t pcpu_chunk_struct_size __read_mostly; | |
fbf59bc9 | 120 | |
a855b84c TH |
121 | /* cpus with the lowest and highest unit addresses */ |
122 | static unsigned int pcpu_low_unit_cpu __read_mostly; | |
123 | static unsigned int pcpu_high_unit_cpu __read_mostly; | |
2f39e637 | 124 | |
fbf59bc9 | 125 | /* the address of the first chunk which starts with the kernel static area */ |
40150d37 | 126 | void *pcpu_base_addr __read_mostly; |
fbf59bc9 TH |
127 | EXPORT_SYMBOL_GPL(pcpu_base_addr); |
128 | ||
fb435d52 TH |
129 | static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */ |
130 | const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */ | |
2f39e637 | 131 | |
6563297c TH |
132 | /* group information, used for vm allocation */ |
133 | static int pcpu_nr_groups __read_mostly; | |
134 | static const unsigned long *pcpu_group_offsets __read_mostly; | |
135 | static const size_t *pcpu_group_sizes __read_mostly; | |
136 | ||
ae9e6bc9 TH |
137 | /* |
138 | * The first chunk which always exists. Note that unlike other | |
139 | * chunks, this one can be allocated and mapped in several different | |
140 | * ways and thus often doesn't live in the vmalloc area. | |
141 | */ | |
142 | static struct pcpu_chunk *pcpu_first_chunk; | |
143 | ||
144 | /* | |
145 | * Optional reserved chunk. This chunk reserves part of the first | |
146 | * chunk and serves it for reserved allocations. The amount of | |
147 | * reserved offset is in pcpu_reserved_chunk_limit. When reserved | |
148 | * area doesn't exist, the following variables contain NULL and 0 | |
149 | * respectively. | |
150 | */ | |
edcb4639 | 151 | static struct pcpu_chunk *pcpu_reserved_chunk; |
edcb4639 TH |
152 | static int pcpu_reserved_chunk_limit; |
153 | ||
fbf59bc9 | 154 | /* |
ccea34b5 TH |
155 | * Synchronization rules. |
156 | * | |
157 | * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former | |
ce3141a2 TH |
158 | * protects allocation/reclaim paths, chunks, populated bitmap and |
159 | * vmalloc mapping. The latter is a spinlock and protects the index | |
160 | * data structures - chunk slots, chunks and area maps in chunks. | |
ccea34b5 TH |
161 | * |
162 | * During allocation, pcpu_alloc_mutex is kept locked all the time and | |
163 | * pcpu_lock is grabbed and released as necessary. All actual memory | |
403a91b1 JK |
164 | * allocations are done using GFP_KERNEL with pcpu_lock released. In |
165 | * general, percpu memory can't be allocated with irq off but | |
166 | * irqsave/restore are still used in alloc path so that it can be used | |
167 | * from early init path - sched_init() specifically. | |
ccea34b5 TH |
168 | * |
169 | * Free path accesses and alters only the index data structures, so it | |
170 | * can be safely called from atomic context. When memory needs to be | |
171 | * returned to the system, free path schedules reclaim_work which | |
172 | * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be | |
173 | * reclaimed, release both locks and frees the chunks. Note that it's | |
174 | * necessary to grab both locks to remove a chunk from circulation as | |
175 | * allocation path might be referencing the chunk with only | |
176 | * pcpu_alloc_mutex locked. | |
fbf59bc9 | 177 | */ |
ccea34b5 TH |
178 | static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */ |
179 | static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */ | |
fbf59bc9 | 180 | |
40150d37 | 181 | static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ |
fbf59bc9 | 182 | |
a56dbddf TH |
183 | /* reclaim work to release fully free chunks, scheduled from free path */ |
184 | static void pcpu_reclaim(struct work_struct *work); | |
185 | static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); | |
186 | ||
020ec653 TH |
187 | static bool pcpu_addr_in_first_chunk(void *addr) |
188 | { | |
189 | void *first_start = pcpu_first_chunk->base_addr; | |
190 | ||
191 | return addr >= first_start && addr < first_start + pcpu_unit_size; | |
192 | } | |
193 | ||
194 | static bool pcpu_addr_in_reserved_chunk(void *addr) | |
195 | { | |
196 | void *first_start = pcpu_first_chunk->base_addr; | |
197 | ||
198 | return addr >= first_start && | |
199 | addr < first_start + pcpu_reserved_chunk_limit; | |
200 | } | |
201 | ||
d9b55eeb | 202 | static int __pcpu_size_to_slot(int size) |
fbf59bc9 | 203 | { |
cae3aeb8 | 204 | int highbit = fls(size); /* size is in bytes */ |
fbf59bc9 TH |
205 | return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); |
206 | } | |
207 | ||
d9b55eeb TH |
208 | static int pcpu_size_to_slot(int size) |
209 | { | |
210 | if (size == pcpu_unit_size) | |
211 | return pcpu_nr_slots - 1; | |
212 | return __pcpu_size_to_slot(size); | |
213 | } | |
214 | ||
fbf59bc9 TH |
215 | static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) |
216 | { | |
217 | if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) | |
218 | return 0; | |
219 | ||
220 | return pcpu_size_to_slot(chunk->free_size); | |
221 | } | |
222 | ||
88999a89 TH |
223 | /* set the pointer to a chunk in a page struct */ |
224 | static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) | |
225 | { | |
226 | page->index = (unsigned long)pcpu; | |
227 | } | |
228 | ||
229 | /* obtain pointer to a chunk from a page struct */ | |
230 | static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) | |
231 | { | |
232 | return (struct pcpu_chunk *)page->index; | |
233 | } | |
234 | ||
235 | static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) | |
fbf59bc9 | 236 | { |
2f39e637 | 237 | return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; |
fbf59bc9 TH |
238 | } |
239 | ||
9983b6f0 TH |
240 | static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, |
241 | unsigned int cpu, int page_idx) | |
fbf59bc9 | 242 | { |
bba174f5 | 243 | return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] + |
fb435d52 | 244 | (page_idx << PAGE_SHIFT); |
fbf59bc9 TH |
245 | } |
246 | ||
88999a89 TH |
247 | static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk, |
248 | int *rs, int *re, int end) | |
ce3141a2 TH |
249 | { |
250 | *rs = find_next_zero_bit(chunk->populated, end, *rs); | |
251 | *re = find_next_bit(chunk->populated, end, *rs + 1); | |
252 | } | |
253 | ||
88999a89 TH |
254 | static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk, |
255 | int *rs, int *re, int end) | |
ce3141a2 TH |
256 | { |
257 | *rs = find_next_bit(chunk->populated, end, *rs); | |
258 | *re = find_next_zero_bit(chunk->populated, end, *rs + 1); | |
259 | } | |
260 | ||
261 | /* | |
262 | * (Un)populated page region iterators. Iterate over (un)populated | |
b595076a | 263 | * page regions between @start and @end in @chunk. @rs and @re should |
ce3141a2 TH |
264 | * be integer variables and will be set to start and end page index of |
265 | * the current region. | |
266 | */ | |
267 | #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ | |
268 | for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ | |
269 | (rs) < (re); \ | |
270 | (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) | |
271 | ||
272 | #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ | |
273 | for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ | |
274 | (rs) < (re); \ | |
275 | (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) | |
276 | ||
fbf59bc9 | 277 | /** |
90459ce0 | 278 | * pcpu_mem_zalloc - allocate memory |
1880d93b | 279 | * @size: bytes to allocate |
fbf59bc9 | 280 | * |
1880d93b | 281 | * Allocate @size bytes. If @size is smaller than PAGE_SIZE, |
90459ce0 | 282 | * kzalloc() is used; otherwise, vzalloc() is used. The returned |
1880d93b | 283 | * memory is always zeroed. |
fbf59bc9 | 284 | * |
ccea34b5 TH |
285 | * CONTEXT: |
286 | * Does GFP_KERNEL allocation. | |
287 | * | |
fbf59bc9 | 288 | * RETURNS: |
1880d93b | 289 | * Pointer to the allocated area on success, NULL on failure. |
fbf59bc9 | 290 | */ |
90459ce0 | 291 | static void *pcpu_mem_zalloc(size_t size) |
fbf59bc9 | 292 | { |
099a19d9 TH |
293 | if (WARN_ON_ONCE(!slab_is_available())) |
294 | return NULL; | |
295 | ||
1880d93b TH |
296 | if (size <= PAGE_SIZE) |
297 | return kzalloc(size, GFP_KERNEL); | |
7af4c093 JJ |
298 | else |
299 | return vzalloc(size); | |
1880d93b | 300 | } |
fbf59bc9 | 301 | |
1880d93b TH |
302 | /** |
303 | * pcpu_mem_free - free memory | |
304 | * @ptr: memory to free | |
305 | * @size: size of the area | |
306 | * | |
90459ce0 | 307 | * Free @ptr. @ptr should have been allocated using pcpu_mem_zalloc(). |
1880d93b TH |
308 | */ |
309 | static void pcpu_mem_free(void *ptr, size_t size) | |
310 | { | |
fbf59bc9 | 311 | if (size <= PAGE_SIZE) |
1880d93b | 312 | kfree(ptr); |
fbf59bc9 | 313 | else |
1880d93b | 314 | vfree(ptr); |
fbf59bc9 TH |
315 | } |
316 | ||
317 | /** | |
318 | * pcpu_chunk_relocate - put chunk in the appropriate chunk slot | |
319 | * @chunk: chunk of interest | |
320 | * @oslot: the previous slot it was on | |
321 | * | |
322 | * This function is called after an allocation or free changed @chunk. | |
323 | * New slot according to the changed state is determined and @chunk is | |
edcb4639 TH |
324 | * moved to the slot. Note that the reserved chunk is never put on |
325 | * chunk slots. | |
ccea34b5 TH |
326 | * |
327 | * CONTEXT: | |
328 | * pcpu_lock. | |
fbf59bc9 TH |
329 | */ |
330 | static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) | |
331 | { | |
332 | int nslot = pcpu_chunk_slot(chunk); | |
333 | ||
edcb4639 | 334 | if (chunk != pcpu_reserved_chunk && oslot != nslot) { |
fbf59bc9 TH |
335 | if (oslot < nslot) |
336 | list_move(&chunk->list, &pcpu_slot[nslot]); | |
337 | else | |
338 | list_move_tail(&chunk->list, &pcpu_slot[nslot]); | |
339 | } | |
340 | } | |
341 | ||
9f7dcf22 | 342 | /** |
833af842 TH |
343 | * pcpu_need_to_extend - determine whether chunk area map needs to be extended |
344 | * @chunk: chunk of interest | |
9f7dcf22 | 345 | * |
833af842 | 346 | * Determine whether area map of @chunk needs to be extended to |
25985edc | 347 | * accommodate a new allocation. |
9f7dcf22 | 348 | * |
ccea34b5 | 349 | * CONTEXT: |
833af842 | 350 | * pcpu_lock. |
ccea34b5 | 351 | * |
9f7dcf22 | 352 | * RETURNS: |
833af842 TH |
353 | * New target map allocation length if extension is necessary, 0 |
354 | * otherwise. | |
9f7dcf22 | 355 | */ |
833af842 | 356 | static int pcpu_need_to_extend(struct pcpu_chunk *chunk) |
9f7dcf22 TH |
357 | { |
358 | int new_alloc; | |
9f7dcf22 | 359 | |
723ad1d9 | 360 | if (chunk->map_alloc >= chunk->map_used + 3) |
9f7dcf22 TH |
361 | return 0; |
362 | ||
363 | new_alloc = PCPU_DFL_MAP_ALLOC; | |
723ad1d9 | 364 | while (new_alloc < chunk->map_used + 3) |
9f7dcf22 TH |
365 | new_alloc *= 2; |
366 | ||
833af842 TH |
367 | return new_alloc; |
368 | } | |
369 | ||
370 | /** | |
371 | * pcpu_extend_area_map - extend area map of a chunk | |
372 | * @chunk: chunk of interest | |
373 | * @new_alloc: new target allocation length of the area map | |
374 | * | |
375 | * Extend area map of @chunk to have @new_alloc entries. | |
376 | * | |
377 | * CONTEXT: | |
378 | * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock. | |
379 | * | |
380 | * RETURNS: | |
381 | * 0 on success, -errno on failure. | |
382 | */ | |
383 | static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) | |
384 | { | |
385 | int *old = NULL, *new = NULL; | |
386 | size_t old_size = 0, new_size = new_alloc * sizeof(new[0]); | |
387 | unsigned long flags; | |
388 | ||
90459ce0 | 389 | new = pcpu_mem_zalloc(new_size); |
833af842 | 390 | if (!new) |
9f7dcf22 | 391 | return -ENOMEM; |
ccea34b5 | 392 | |
833af842 TH |
393 | /* acquire pcpu_lock and switch to new area map */ |
394 | spin_lock_irqsave(&pcpu_lock, flags); | |
395 | ||
396 | if (new_alloc <= chunk->map_alloc) | |
397 | goto out_unlock; | |
9f7dcf22 | 398 | |
833af842 | 399 | old_size = chunk->map_alloc * sizeof(chunk->map[0]); |
a002d148 HS |
400 | old = chunk->map; |
401 | ||
402 | memcpy(new, old, old_size); | |
9f7dcf22 | 403 | |
9f7dcf22 TH |
404 | chunk->map_alloc = new_alloc; |
405 | chunk->map = new; | |
833af842 TH |
406 | new = NULL; |
407 | ||
408 | out_unlock: | |
409 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
410 | ||
411 | /* | |
412 | * pcpu_mem_free() might end up calling vfree() which uses | |
413 | * IRQ-unsafe lock and thus can't be called under pcpu_lock. | |
414 | */ | |
415 | pcpu_mem_free(old, old_size); | |
416 | pcpu_mem_free(new, new_size); | |
417 | ||
9f7dcf22 TH |
418 | return 0; |
419 | } | |
420 | ||
fbf59bc9 TH |
421 | /** |
422 | * pcpu_alloc_area - allocate area from a pcpu_chunk | |
423 | * @chunk: chunk of interest | |
cae3aeb8 | 424 | * @size: wanted size in bytes |
fbf59bc9 TH |
425 | * @align: wanted align |
426 | * | |
427 | * Try to allocate @size bytes area aligned at @align from @chunk. | |
428 | * Note that this function only allocates the offset. It doesn't | |
429 | * populate or map the area. | |
430 | * | |
9f7dcf22 TH |
431 | * @chunk->map must have at least two free slots. |
432 | * | |
ccea34b5 TH |
433 | * CONTEXT: |
434 | * pcpu_lock. | |
435 | * | |
fbf59bc9 | 436 | * RETURNS: |
9f7dcf22 TH |
437 | * Allocated offset in @chunk on success, -1 if no matching area is |
438 | * found. | |
fbf59bc9 TH |
439 | */ |
440 | static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align) | |
441 | { | |
442 | int oslot = pcpu_chunk_slot(chunk); | |
443 | int max_contig = 0; | |
444 | int i, off; | |
3d331ad7 | 445 | bool seen_free = false; |
723ad1d9 | 446 | int *p; |
fbf59bc9 | 447 | |
3d331ad7 | 448 | for (i = chunk->first_free, p = chunk->map + i; i < chunk->map_used; i++, p++) { |
fbf59bc9 | 449 | int head, tail; |
723ad1d9 AV |
450 | int this_size; |
451 | ||
452 | off = *p; | |
453 | if (off & 1) | |
454 | continue; | |
fbf59bc9 TH |
455 | |
456 | /* extra for alignment requirement */ | |
457 | head = ALIGN(off, align) - off; | |
fbf59bc9 | 458 | |
723ad1d9 AV |
459 | this_size = (p[1] & ~1) - off; |
460 | if (this_size < head + size) { | |
3d331ad7 AV |
461 | if (!seen_free) { |
462 | chunk->first_free = i; | |
463 | seen_free = true; | |
464 | } | |
723ad1d9 | 465 | max_contig = max(this_size, max_contig); |
fbf59bc9 TH |
466 | continue; |
467 | } | |
468 | ||
469 | /* | |
470 | * If head is small or the previous block is free, | |
471 | * merge'em. Note that 'small' is defined as smaller | |
472 | * than sizeof(int), which is very small but isn't too | |
473 | * uncommon for percpu allocations. | |
474 | */ | |
723ad1d9 | 475 | if (head && (head < sizeof(int) || !(p[-1] & 1))) { |
21ddfd38 | 476 | *p = off += head; |
723ad1d9 | 477 | if (p[-1] & 1) |
fbf59bc9 | 478 | chunk->free_size -= head; |
21ddfd38 JZ |
479 | else |
480 | max_contig = max(*p - p[-1], max_contig); | |
723ad1d9 | 481 | this_size -= head; |
fbf59bc9 TH |
482 | head = 0; |
483 | } | |
484 | ||
485 | /* if tail is small, just keep it around */ | |
723ad1d9 AV |
486 | tail = this_size - head - size; |
487 | if (tail < sizeof(int)) { | |
fbf59bc9 | 488 | tail = 0; |
723ad1d9 AV |
489 | size = this_size - head; |
490 | } | |
fbf59bc9 TH |
491 | |
492 | /* split if warranted */ | |
493 | if (head || tail) { | |
706c16f2 AV |
494 | int nr_extra = !!head + !!tail; |
495 | ||
496 | /* insert new subblocks */ | |
723ad1d9 | 497 | memmove(p + nr_extra + 1, p + 1, |
706c16f2 AV |
498 | sizeof(chunk->map[0]) * (chunk->map_used - i)); |
499 | chunk->map_used += nr_extra; | |
500 | ||
fbf59bc9 | 501 | if (head) { |
3d331ad7 AV |
502 | if (!seen_free) { |
503 | chunk->first_free = i; | |
504 | seen_free = true; | |
505 | } | |
723ad1d9 AV |
506 | *++p = off += head; |
507 | ++i; | |
706c16f2 AV |
508 | max_contig = max(head, max_contig); |
509 | } | |
510 | if (tail) { | |
723ad1d9 | 511 | p[1] = off + size; |
706c16f2 | 512 | max_contig = max(tail, max_contig); |
fbf59bc9 | 513 | } |
fbf59bc9 TH |
514 | } |
515 | ||
3d331ad7 AV |
516 | if (!seen_free) |
517 | chunk->first_free = i + 1; | |
518 | ||
fbf59bc9 | 519 | /* update hint and mark allocated */ |
723ad1d9 | 520 | if (i + 1 == chunk->map_used) |
fbf59bc9 TH |
521 | chunk->contig_hint = max_contig; /* fully scanned */ |
522 | else | |
523 | chunk->contig_hint = max(chunk->contig_hint, | |
524 | max_contig); | |
525 | ||
723ad1d9 AV |
526 | chunk->free_size -= size; |
527 | *p |= 1; | |
fbf59bc9 TH |
528 | |
529 | pcpu_chunk_relocate(chunk, oslot); | |
530 | return off; | |
531 | } | |
532 | ||
533 | chunk->contig_hint = max_contig; /* fully scanned */ | |
534 | pcpu_chunk_relocate(chunk, oslot); | |
535 | ||
9f7dcf22 TH |
536 | /* tell the upper layer that this chunk has no matching area */ |
537 | return -1; | |
fbf59bc9 TH |
538 | } |
539 | ||
540 | /** | |
541 | * pcpu_free_area - free area to a pcpu_chunk | |
542 | * @chunk: chunk of interest | |
543 | * @freeme: offset of area to free | |
544 | * | |
545 | * Free area starting from @freeme to @chunk. Note that this function | |
546 | * only modifies the allocation map. It doesn't depopulate or unmap | |
547 | * the area. | |
ccea34b5 TH |
548 | * |
549 | * CONTEXT: | |
550 | * pcpu_lock. | |
fbf59bc9 TH |
551 | */ |
552 | static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme) | |
553 | { | |
554 | int oslot = pcpu_chunk_slot(chunk); | |
723ad1d9 AV |
555 | int off = 0; |
556 | unsigned i, j; | |
557 | int to_free = 0; | |
558 | int *p; | |
559 | ||
560 | freeme |= 1; /* we are searching for <given offset, in use> pair */ | |
561 | ||
562 | i = 0; | |
563 | j = chunk->map_used; | |
564 | while (i != j) { | |
565 | unsigned k = (i + j) / 2; | |
566 | off = chunk->map[k]; | |
567 | if (off < freeme) | |
568 | i = k + 1; | |
569 | else if (off > freeme) | |
570 | j = k; | |
571 | else | |
572 | i = j = k; | |
573 | } | |
fbf59bc9 | 574 | BUG_ON(off != freeme); |
fbf59bc9 | 575 | |
3d331ad7 AV |
576 | if (i < chunk->first_free) |
577 | chunk->first_free = i; | |
578 | ||
723ad1d9 AV |
579 | p = chunk->map + i; |
580 | *p = off &= ~1; | |
581 | chunk->free_size += (p[1] & ~1) - off; | |
fbf59bc9 | 582 | |
723ad1d9 AV |
583 | /* merge with next? */ |
584 | if (!(p[1] & 1)) | |
585 | to_free++; | |
fbf59bc9 | 586 | /* merge with previous? */ |
723ad1d9 AV |
587 | if (i > 0 && !(p[-1] & 1)) { |
588 | to_free++; | |
fbf59bc9 | 589 | i--; |
723ad1d9 | 590 | p--; |
fbf59bc9 | 591 | } |
723ad1d9 AV |
592 | if (to_free) { |
593 | chunk->map_used -= to_free; | |
594 | memmove(p + 1, p + 1 + to_free, | |
595 | (chunk->map_used - i) * sizeof(chunk->map[0])); | |
fbf59bc9 TH |
596 | } |
597 | ||
723ad1d9 | 598 | chunk->contig_hint = max(chunk->map[i + 1] - chunk->map[i] - 1, chunk->contig_hint); |
fbf59bc9 TH |
599 | pcpu_chunk_relocate(chunk, oslot); |
600 | } | |
601 | ||
6081089f TH |
602 | static struct pcpu_chunk *pcpu_alloc_chunk(void) |
603 | { | |
604 | struct pcpu_chunk *chunk; | |
605 | ||
90459ce0 | 606 | chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size); |
6081089f TH |
607 | if (!chunk) |
608 | return NULL; | |
609 | ||
90459ce0 BL |
610 | chunk->map = pcpu_mem_zalloc(PCPU_DFL_MAP_ALLOC * |
611 | sizeof(chunk->map[0])); | |
6081089f | 612 | if (!chunk->map) { |
5a838c3b | 613 | pcpu_mem_free(chunk, pcpu_chunk_struct_size); |
6081089f TH |
614 | return NULL; |
615 | } | |
616 | ||
617 | chunk->map_alloc = PCPU_DFL_MAP_ALLOC; | |
723ad1d9 AV |
618 | chunk->map[0] = 0; |
619 | chunk->map[1] = pcpu_unit_size | 1; | |
620 | chunk->map_used = 1; | |
6081089f TH |
621 | |
622 | INIT_LIST_HEAD(&chunk->list); | |
623 | chunk->free_size = pcpu_unit_size; | |
624 | chunk->contig_hint = pcpu_unit_size; | |
625 | ||
626 | return chunk; | |
627 | } | |
628 | ||
629 | static void pcpu_free_chunk(struct pcpu_chunk *chunk) | |
630 | { | |
631 | if (!chunk) | |
632 | return; | |
633 | pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0])); | |
b4916cb1 | 634 | pcpu_mem_free(chunk, pcpu_chunk_struct_size); |
6081089f TH |
635 | } |
636 | ||
9f645532 TH |
637 | /* |
638 | * Chunk management implementation. | |
639 | * | |
640 | * To allow different implementations, chunk alloc/free and | |
641 | * [de]population are implemented in a separate file which is pulled | |
642 | * into this file and compiled together. The following functions | |
643 | * should be implemented. | |
644 | * | |
645 | * pcpu_populate_chunk - populate the specified range of a chunk | |
646 | * pcpu_depopulate_chunk - depopulate the specified range of a chunk | |
647 | * pcpu_create_chunk - create a new chunk | |
648 | * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop | |
649 | * pcpu_addr_to_page - translate address to physical address | |
650 | * pcpu_verify_alloc_info - check alloc_info is acceptable during init | |
fbf59bc9 | 651 | */ |
9f645532 TH |
652 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size); |
653 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); | |
654 | static struct pcpu_chunk *pcpu_create_chunk(void); | |
655 | static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); | |
656 | static struct page *pcpu_addr_to_page(void *addr); | |
657 | static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); | |
fbf59bc9 | 658 | |
b0c9778b TH |
659 | #ifdef CONFIG_NEED_PER_CPU_KM |
660 | #include "percpu-km.c" | |
661 | #else | |
9f645532 | 662 | #include "percpu-vm.c" |
b0c9778b | 663 | #endif |
fbf59bc9 | 664 | |
88999a89 TH |
665 | /** |
666 | * pcpu_chunk_addr_search - determine chunk containing specified address | |
667 | * @addr: address for which the chunk needs to be determined. | |
668 | * | |
669 | * RETURNS: | |
670 | * The address of the found chunk. | |
671 | */ | |
672 | static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) | |
673 | { | |
674 | /* is it in the first chunk? */ | |
675 | if (pcpu_addr_in_first_chunk(addr)) { | |
676 | /* is it in the reserved area? */ | |
677 | if (pcpu_addr_in_reserved_chunk(addr)) | |
678 | return pcpu_reserved_chunk; | |
679 | return pcpu_first_chunk; | |
680 | } | |
681 | ||
682 | /* | |
683 | * The address is relative to unit0 which might be unused and | |
684 | * thus unmapped. Offset the address to the unit space of the | |
685 | * current processor before looking it up in the vmalloc | |
686 | * space. Note that any possible cpu id can be used here, so | |
687 | * there's no need to worry about preemption or cpu hotplug. | |
688 | */ | |
689 | addr += pcpu_unit_offsets[raw_smp_processor_id()]; | |
9f645532 | 690 | return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); |
88999a89 TH |
691 | } |
692 | ||
fbf59bc9 | 693 | /** |
edcb4639 | 694 | * pcpu_alloc - the percpu allocator |
cae3aeb8 | 695 | * @size: size of area to allocate in bytes |
fbf59bc9 | 696 | * @align: alignment of area (max PAGE_SIZE) |
edcb4639 | 697 | * @reserved: allocate from the reserved chunk if available |
fbf59bc9 | 698 | * |
ccea34b5 TH |
699 | * Allocate percpu area of @size bytes aligned at @align. |
700 | * | |
701 | * CONTEXT: | |
702 | * Does GFP_KERNEL allocation. | |
fbf59bc9 TH |
703 | * |
704 | * RETURNS: | |
705 | * Percpu pointer to the allocated area on success, NULL on failure. | |
706 | */ | |
43cf38eb | 707 | static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) |
fbf59bc9 | 708 | { |
f2badb0c | 709 | static int warn_limit = 10; |
fbf59bc9 | 710 | struct pcpu_chunk *chunk; |
f2badb0c | 711 | const char *err; |
833af842 | 712 | int slot, off, new_alloc; |
403a91b1 | 713 | unsigned long flags; |
f528f0b8 | 714 | void __percpu *ptr; |
fbf59bc9 | 715 | |
723ad1d9 AV |
716 | /* |
717 | * We want the lowest bit of offset available for in-use/free | |
2f69fa82 | 718 | * indicator, so force >= 16bit alignment and make size even. |
723ad1d9 AV |
719 | */ |
720 | if (unlikely(align < 2)) | |
721 | align = 2; | |
722 | ||
fb009e3a | 723 | size = ALIGN(size, 2); |
2f69fa82 | 724 | |
8d408b4b | 725 | if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { |
fbf59bc9 TH |
726 | WARN(true, "illegal size (%zu) or align (%zu) for " |
727 | "percpu allocation\n", size, align); | |
728 | return NULL; | |
729 | } | |
730 | ||
ccea34b5 | 731 | mutex_lock(&pcpu_alloc_mutex); |
403a91b1 | 732 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 733 | |
edcb4639 TH |
734 | /* serve reserved allocations from the reserved chunk if available */ |
735 | if (reserved && pcpu_reserved_chunk) { | |
736 | chunk = pcpu_reserved_chunk; | |
833af842 TH |
737 | |
738 | if (size > chunk->contig_hint) { | |
739 | err = "alloc from reserved chunk failed"; | |
ccea34b5 | 740 | goto fail_unlock; |
f2badb0c | 741 | } |
833af842 TH |
742 | |
743 | while ((new_alloc = pcpu_need_to_extend(chunk))) { | |
744 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
745 | if (pcpu_extend_area_map(chunk, new_alloc) < 0) { | |
746 | err = "failed to extend area map of reserved chunk"; | |
747 | goto fail_unlock_mutex; | |
748 | } | |
749 | spin_lock_irqsave(&pcpu_lock, flags); | |
750 | } | |
751 | ||
edcb4639 TH |
752 | off = pcpu_alloc_area(chunk, size, align); |
753 | if (off >= 0) | |
754 | goto area_found; | |
833af842 | 755 | |
f2badb0c | 756 | err = "alloc from reserved chunk failed"; |
ccea34b5 | 757 | goto fail_unlock; |
edcb4639 TH |
758 | } |
759 | ||
ccea34b5 | 760 | restart: |
edcb4639 | 761 | /* search through normal chunks */ |
fbf59bc9 TH |
762 | for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { |
763 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { | |
764 | if (size > chunk->contig_hint) | |
765 | continue; | |
ccea34b5 | 766 | |
833af842 TH |
767 | new_alloc = pcpu_need_to_extend(chunk); |
768 | if (new_alloc) { | |
769 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
770 | if (pcpu_extend_area_map(chunk, | |
771 | new_alloc) < 0) { | |
772 | err = "failed to extend area map"; | |
773 | goto fail_unlock_mutex; | |
774 | } | |
775 | spin_lock_irqsave(&pcpu_lock, flags); | |
776 | /* | |
777 | * pcpu_lock has been dropped, need to | |
778 | * restart cpu_slot list walking. | |
779 | */ | |
780 | goto restart; | |
ccea34b5 TH |
781 | } |
782 | ||
fbf59bc9 TH |
783 | off = pcpu_alloc_area(chunk, size, align); |
784 | if (off >= 0) | |
785 | goto area_found; | |
fbf59bc9 TH |
786 | } |
787 | } | |
788 | ||
789 | /* hmmm... no space left, create a new chunk */ | |
403a91b1 | 790 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 | 791 | |
6081089f | 792 | chunk = pcpu_create_chunk(); |
f2badb0c TH |
793 | if (!chunk) { |
794 | err = "failed to allocate new chunk"; | |
ccea34b5 | 795 | goto fail_unlock_mutex; |
f2badb0c | 796 | } |
ccea34b5 | 797 | |
403a91b1 | 798 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 799 | pcpu_chunk_relocate(chunk, -1); |
ccea34b5 | 800 | goto restart; |
fbf59bc9 TH |
801 | |
802 | area_found: | |
403a91b1 | 803 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 | 804 | |
fbf59bc9 TH |
805 | /* populate, map and clear the area */ |
806 | if (pcpu_populate_chunk(chunk, off, size)) { | |
403a91b1 | 807 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 808 | pcpu_free_area(chunk, off); |
f2badb0c | 809 | err = "failed to populate"; |
ccea34b5 | 810 | goto fail_unlock; |
fbf59bc9 TH |
811 | } |
812 | ||
ccea34b5 TH |
813 | mutex_unlock(&pcpu_alloc_mutex); |
814 | ||
bba174f5 | 815 | /* return address relative to base address */ |
f528f0b8 CM |
816 | ptr = __addr_to_pcpu_ptr(chunk->base_addr + off); |
817 | kmemleak_alloc_percpu(ptr, size); | |
818 | return ptr; | |
ccea34b5 TH |
819 | |
820 | fail_unlock: | |
403a91b1 | 821 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 TH |
822 | fail_unlock_mutex: |
823 | mutex_unlock(&pcpu_alloc_mutex); | |
f2badb0c TH |
824 | if (warn_limit) { |
825 | pr_warning("PERCPU: allocation failed, size=%zu align=%zu, " | |
826 | "%s\n", size, align, err); | |
827 | dump_stack(); | |
828 | if (!--warn_limit) | |
829 | pr_info("PERCPU: limit reached, disable warning\n"); | |
830 | } | |
ccea34b5 | 831 | return NULL; |
fbf59bc9 | 832 | } |
edcb4639 TH |
833 | |
834 | /** | |
835 | * __alloc_percpu - allocate dynamic percpu area | |
836 | * @size: size of area to allocate in bytes | |
837 | * @align: alignment of area (max PAGE_SIZE) | |
838 | * | |
9329ba97 TH |
839 | * Allocate zero-filled percpu area of @size bytes aligned at @align. |
840 | * Might sleep. Might trigger writeouts. | |
edcb4639 | 841 | * |
ccea34b5 TH |
842 | * CONTEXT: |
843 | * Does GFP_KERNEL allocation. | |
844 | * | |
edcb4639 TH |
845 | * RETURNS: |
846 | * Percpu pointer to the allocated area on success, NULL on failure. | |
847 | */ | |
43cf38eb | 848 | void __percpu *__alloc_percpu(size_t size, size_t align) |
edcb4639 TH |
849 | { |
850 | return pcpu_alloc(size, align, false); | |
851 | } | |
fbf59bc9 TH |
852 | EXPORT_SYMBOL_GPL(__alloc_percpu); |
853 | ||
edcb4639 TH |
854 | /** |
855 | * __alloc_reserved_percpu - allocate reserved percpu area | |
856 | * @size: size of area to allocate in bytes | |
857 | * @align: alignment of area (max PAGE_SIZE) | |
858 | * | |
9329ba97 TH |
859 | * Allocate zero-filled percpu area of @size bytes aligned at @align |
860 | * from reserved percpu area if arch has set it up; otherwise, | |
861 | * allocation is served from the same dynamic area. Might sleep. | |
862 | * Might trigger writeouts. | |
edcb4639 | 863 | * |
ccea34b5 TH |
864 | * CONTEXT: |
865 | * Does GFP_KERNEL allocation. | |
866 | * | |
edcb4639 TH |
867 | * RETURNS: |
868 | * Percpu pointer to the allocated area on success, NULL on failure. | |
869 | */ | |
43cf38eb | 870 | void __percpu *__alloc_reserved_percpu(size_t size, size_t align) |
edcb4639 TH |
871 | { |
872 | return pcpu_alloc(size, align, true); | |
873 | } | |
874 | ||
a56dbddf TH |
875 | /** |
876 | * pcpu_reclaim - reclaim fully free chunks, workqueue function | |
877 | * @work: unused | |
878 | * | |
879 | * Reclaim all fully free chunks except for the first one. | |
ccea34b5 TH |
880 | * |
881 | * CONTEXT: | |
882 | * workqueue context. | |
a56dbddf TH |
883 | */ |
884 | static void pcpu_reclaim(struct work_struct *work) | |
fbf59bc9 | 885 | { |
a56dbddf TH |
886 | LIST_HEAD(todo); |
887 | struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; | |
888 | struct pcpu_chunk *chunk, *next; | |
889 | ||
ccea34b5 TH |
890 | mutex_lock(&pcpu_alloc_mutex); |
891 | spin_lock_irq(&pcpu_lock); | |
a56dbddf TH |
892 | |
893 | list_for_each_entry_safe(chunk, next, head, list) { | |
894 | WARN_ON(chunk->immutable); | |
895 | ||
896 | /* spare the first one */ | |
897 | if (chunk == list_first_entry(head, struct pcpu_chunk, list)) | |
898 | continue; | |
899 | ||
a56dbddf TH |
900 | list_move(&chunk->list, &todo); |
901 | } | |
902 | ||
ccea34b5 | 903 | spin_unlock_irq(&pcpu_lock); |
a56dbddf TH |
904 | |
905 | list_for_each_entry_safe(chunk, next, &todo, list) { | |
ce3141a2 | 906 | pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); |
6081089f | 907 | pcpu_destroy_chunk(chunk); |
a56dbddf | 908 | } |
971f3918 TH |
909 | |
910 | mutex_unlock(&pcpu_alloc_mutex); | |
fbf59bc9 TH |
911 | } |
912 | ||
913 | /** | |
914 | * free_percpu - free percpu area | |
915 | * @ptr: pointer to area to free | |
916 | * | |
ccea34b5 TH |
917 | * Free percpu area @ptr. |
918 | * | |
919 | * CONTEXT: | |
920 | * Can be called from atomic context. | |
fbf59bc9 | 921 | */ |
43cf38eb | 922 | void free_percpu(void __percpu *ptr) |
fbf59bc9 | 923 | { |
129182e5 | 924 | void *addr; |
fbf59bc9 | 925 | struct pcpu_chunk *chunk; |
ccea34b5 | 926 | unsigned long flags; |
fbf59bc9 TH |
927 | int off; |
928 | ||
929 | if (!ptr) | |
930 | return; | |
931 | ||
f528f0b8 CM |
932 | kmemleak_free_percpu(ptr); |
933 | ||
129182e5 AM |
934 | addr = __pcpu_ptr_to_addr(ptr); |
935 | ||
ccea34b5 | 936 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 TH |
937 | |
938 | chunk = pcpu_chunk_addr_search(addr); | |
bba174f5 | 939 | off = addr - chunk->base_addr; |
fbf59bc9 TH |
940 | |
941 | pcpu_free_area(chunk, off); | |
942 | ||
a56dbddf | 943 | /* if there are more than one fully free chunks, wake up grim reaper */ |
fbf59bc9 TH |
944 | if (chunk->free_size == pcpu_unit_size) { |
945 | struct pcpu_chunk *pos; | |
946 | ||
a56dbddf | 947 | list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) |
fbf59bc9 | 948 | if (pos != chunk) { |
a56dbddf | 949 | schedule_work(&pcpu_reclaim_work); |
fbf59bc9 TH |
950 | break; |
951 | } | |
952 | } | |
953 | ||
ccea34b5 | 954 | spin_unlock_irqrestore(&pcpu_lock, flags); |
fbf59bc9 TH |
955 | } |
956 | EXPORT_SYMBOL_GPL(free_percpu); | |
957 | ||
10fad5e4 TH |
958 | /** |
959 | * is_kernel_percpu_address - test whether address is from static percpu area | |
960 | * @addr: address to test | |
961 | * | |
962 | * Test whether @addr belongs to in-kernel static percpu area. Module | |
963 | * static percpu areas are not considered. For those, use | |
964 | * is_module_percpu_address(). | |
965 | * | |
966 | * RETURNS: | |
967 | * %true if @addr is from in-kernel static percpu area, %false otherwise. | |
968 | */ | |
969 | bool is_kernel_percpu_address(unsigned long addr) | |
970 | { | |
bbddff05 | 971 | #ifdef CONFIG_SMP |
10fad5e4 TH |
972 | const size_t static_size = __per_cpu_end - __per_cpu_start; |
973 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); | |
974 | unsigned int cpu; | |
975 | ||
976 | for_each_possible_cpu(cpu) { | |
977 | void *start = per_cpu_ptr(base, cpu); | |
978 | ||
979 | if ((void *)addr >= start && (void *)addr < start + static_size) | |
980 | return true; | |
981 | } | |
bbddff05 TH |
982 | #endif |
983 | /* on UP, can't distinguish from other static vars, always false */ | |
10fad5e4 TH |
984 | return false; |
985 | } | |
986 | ||
3b034b0d VG |
987 | /** |
988 | * per_cpu_ptr_to_phys - convert translated percpu address to physical address | |
989 | * @addr: the address to be converted to physical address | |
990 | * | |
991 | * Given @addr which is dereferenceable address obtained via one of | |
992 | * percpu access macros, this function translates it into its physical | |
993 | * address. The caller is responsible for ensuring @addr stays valid | |
994 | * until this function finishes. | |
995 | * | |
67589c71 DY |
996 | * percpu allocator has special setup for the first chunk, which currently |
997 | * supports either embedding in linear address space or vmalloc mapping, | |
998 | * and, from the second one, the backing allocator (currently either vm or | |
999 | * km) provides translation. | |
1000 | * | |
1001 | * The addr can be tranlated simply without checking if it falls into the | |
1002 | * first chunk. But the current code reflects better how percpu allocator | |
1003 | * actually works, and the verification can discover both bugs in percpu | |
1004 | * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current | |
1005 | * code. | |
1006 | * | |
3b034b0d VG |
1007 | * RETURNS: |
1008 | * The physical address for @addr. | |
1009 | */ | |
1010 | phys_addr_t per_cpu_ptr_to_phys(void *addr) | |
1011 | { | |
9983b6f0 TH |
1012 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); |
1013 | bool in_first_chunk = false; | |
a855b84c | 1014 | unsigned long first_low, first_high; |
9983b6f0 TH |
1015 | unsigned int cpu; |
1016 | ||
1017 | /* | |
a855b84c | 1018 | * The following test on unit_low/high isn't strictly |
9983b6f0 TH |
1019 | * necessary but will speed up lookups of addresses which |
1020 | * aren't in the first chunk. | |
1021 | */ | |
a855b84c TH |
1022 | first_low = pcpu_chunk_addr(pcpu_first_chunk, pcpu_low_unit_cpu, 0); |
1023 | first_high = pcpu_chunk_addr(pcpu_first_chunk, pcpu_high_unit_cpu, | |
1024 | pcpu_unit_pages); | |
1025 | if ((unsigned long)addr >= first_low && | |
1026 | (unsigned long)addr < first_high) { | |
9983b6f0 TH |
1027 | for_each_possible_cpu(cpu) { |
1028 | void *start = per_cpu_ptr(base, cpu); | |
1029 | ||
1030 | if (addr >= start && addr < start + pcpu_unit_size) { | |
1031 | in_first_chunk = true; | |
1032 | break; | |
1033 | } | |
1034 | } | |
1035 | } | |
1036 | ||
1037 | if (in_first_chunk) { | |
eac522ef | 1038 | if (!is_vmalloc_addr(addr)) |
020ec653 TH |
1039 | return __pa(addr); |
1040 | else | |
9f57bd4d ES |
1041 | return page_to_phys(vmalloc_to_page(addr)) + |
1042 | offset_in_page(addr); | |
020ec653 | 1043 | } else |
9f57bd4d ES |
1044 | return page_to_phys(pcpu_addr_to_page(addr)) + |
1045 | offset_in_page(addr); | |
3b034b0d VG |
1046 | } |
1047 | ||
fbf59bc9 | 1048 | /** |
fd1e8a1f TH |
1049 | * pcpu_alloc_alloc_info - allocate percpu allocation info |
1050 | * @nr_groups: the number of groups | |
1051 | * @nr_units: the number of units | |
1052 | * | |
1053 | * Allocate ai which is large enough for @nr_groups groups containing | |
1054 | * @nr_units units. The returned ai's groups[0].cpu_map points to the | |
1055 | * cpu_map array which is long enough for @nr_units and filled with | |
1056 | * NR_CPUS. It's the caller's responsibility to initialize cpu_map | |
1057 | * pointer of other groups. | |
1058 | * | |
1059 | * RETURNS: | |
1060 | * Pointer to the allocated pcpu_alloc_info on success, NULL on | |
1061 | * failure. | |
1062 | */ | |
1063 | struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, | |
1064 | int nr_units) | |
1065 | { | |
1066 | struct pcpu_alloc_info *ai; | |
1067 | size_t base_size, ai_size; | |
1068 | void *ptr; | |
1069 | int unit; | |
1070 | ||
1071 | base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), | |
1072 | __alignof__(ai->groups[0].cpu_map[0])); | |
1073 | ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); | |
1074 | ||
999c17e3 | 1075 | ptr = memblock_virt_alloc_nopanic(PFN_ALIGN(ai_size), 0); |
fd1e8a1f TH |
1076 | if (!ptr) |
1077 | return NULL; | |
1078 | ai = ptr; | |
1079 | ptr += base_size; | |
1080 | ||
1081 | ai->groups[0].cpu_map = ptr; | |
1082 | ||
1083 | for (unit = 0; unit < nr_units; unit++) | |
1084 | ai->groups[0].cpu_map[unit] = NR_CPUS; | |
1085 | ||
1086 | ai->nr_groups = nr_groups; | |
1087 | ai->__ai_size = PFN_ALIGN(ai_size); | |
1088 | ||
1089 | return ai; | |
1090 | } | |
1091 | ||
1092 | /** | |
1093 | * pcpu_free_alloc_info - free percpu allocation info | |
1094 | * @ai: pcpu_alloc_info to free | |
1095 | * | |
1096 | * Free @ai which was allocated by pcpu_alloc_alloc_info(). | |
1097 | */ | |
1098 | void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) | |
1099 | { | |
999c17e3 | 1100 | memblock_free_early(__pa(ai), ai->__ai_size); |
fd1e8a1f TH |
1101 | } |
1102 | ||
fd1e8a1f TH |
1103 | /** |
1104 | * pcpu_dump_alloc_info - print out information about pcpu_alloc_info | |
1105 | * @lvl: loglevel | |
1106 | * @ai: allocation info to dump | |
1107 | * | |
1108 | * Print out information about @ai using loglevel @lvl. | |
1109 | */ | |
1110 | static void pcpu_dump_alloc_info(const char *lvl, | |
1111 | const struct pcpu_alloc_info *ai) | |
033e48fb | 1112 | { |
fd1e8a1f | 1113 | int group_width = 1, cpu_width = 1, width; |
033e48fb | 1114 | char empty_str[] = "--------"; |
fd1e8a1f TH |
1115 | int alloc = 0, alloc_end = 0; |
1116 | int group, v; | |
1117 | int upa, apl; /* units per alloc, allocs per line */ | |
1118 | ||
1119 | v = ai->nr_groups; | |
1120 | while (v /= 10) | |
1121 | group_width++; | |
033e48fb | 1122 | |
fd1e8a1f | 1123 | v = num_possible_cpus(); |
033e48fb | 1124 | while (v /= 10) |
fd1e8a1f TH |
1125 | cpu_width++; |
1126 | empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; | |
033e48fb | 1127 | |
fd1e8a1f TH |
1128 | upa = ai->alloc_size / ai->unit_size; |
1129 | width = upa * (cpu_width + 1) + group_width + 3; | |
1130 | apl = rounddown_pow_of_two(max(60 / width, 1)); | |
033e48fb | 1131 | |
fd1e8a1f TH |
1132 | printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", |
1133 | lvl, ai->static_size, ai->reserved_size, ai->dyn_size, | |
1134 | ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); | |
033e48fb | 1135 | |
fd1e8a1f TH |
1136 | for (group = 0; group < ai->nr_groups; group++) { |
1137 | const struct pcpu_group_info *gi = &ai->groups[group]; | |
1138 | int unit = 0, unit_end = 0; | |
1139 | ||
1140 | BUG_ON(gi->nr_units % upa); | |
1141 | for (alloc_end += gi->nr_units / upa; | |
1142 | alloc < alloc_end; alloc++) { | |
1143 | if (!(alloc % apl)) { | |
cb129820 | 1144 | printk(KERN_CONT "\n"); |
fd1e8a1f TH |
1145 | printk("%spcpu-alloc: ", lvl); |
1146 | } | |
cb129820 | 1147 | printk(KERN_CONT "[%0*d] ", group_width, group); |
fd1e8a1f TH |
1148 | |
1149 | for (unit_end += upa; unit < unit_end; unit++) | |
1150 | if (gi->cpu_map[unit] != NR_CPUS) | |
cb129820 | 1151 | printk(KERN_CONT "%0*d ", cpu_width, |
fd1e8a1f TH |
1152 | gi->cpu_map[unit]); |
1153 | else | |
cb129820 | 1154 | printk(KERN_CONT "%s ", empty_str); |
033e48fb | 1155 | } |
033e48fb | 1156 | } |
cb129820 | 1157 | printk(KERN_CONT "\n"); |
033e48fb | 1158 | } |
033e48fb | 1159 | |
fbf59bc9 | 1160 | /** |
8d408b4b | 1161 | * pcpu_setup_first_chunk - initialize the first percpu chunk |
fd1e8a1f | 1162 | * @ai: pcpu_alloc_info describing how to percpu area is shaped |
38a6be52 | 1163 | * @base_addr: mapped address |
8d408b4b TH |
1164 | * |
1165 | * Initialize the first percpu chunk which contains the kernel static | |
1166 | * perpcu area. This function is to be called from arch percpu area | |
38a6be52 | 1167 | * setup path. |
8d408b4b | 1168 | * |
fd1e8a1f TH |
1169 | * @ai contains all information necessary to initialize the first |
1170 | * chunk and prime the dynamic percpu allocator. | |
1171 | * | |
1172 | * @ai->static_size is the size of static percpu area. | |
1173 | * | |
1174 | * @ai->reserved_size, if non-zero, specifies the amount of bytes to | |
edcb4639 TH |
1175 | * reserve after the static area in the first chunk. This reserves |
1176 | * the first chunk such that it's available only through reserved | |
1177 | * percpu allocation. This is primarily used to serve module percpu | |
1178 | * static areas on architectures where the addressing model has | |
1179 | * limited offset range for symbol relocations to guarantee module | |
1180 | * percpu symbols fall inside the relocatable range. | |
1181 | * | |
fd1e8a1f TH |
1182 | * @ai->dyn_size determines the number of bytes available for dynamic |
1183 | * allocation in the first chunk. The area between @ai->static_size + | |
1184 | * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. | |
6074d5b0 | 1185 | * |
fd1e8a1f TH |
1186 | * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE |
1187 | * and equal to or larger than @ai->static_size + @ai->reserved_size + | |
1188 | * @ai->dyn_size. | |
8d408b4b | 1189 | * |
fd1e8a1f TH |
1190 | * @ai->atom_size is the allocation atom size and used as alignment |
1191 | * for vm areas. | |
8d408b4b | 1192 | * |
fd1e8a1f TH |
1193 | * @ai->alloc_size is the allocation size and always multiple of |
1194 | * @ai->atom_size. This is larger than @ai->atom_size if | |
1195 | * @ai->unit_size is larger than @ai->atom_size. | |
1196 | * | |
1197 | * @ai->nr_groups and @ai->groups describe virtual memory layout of | |
1198 | * percpu areas. Units which should be colocated are put into the | |
1199 | * same group. Dynamic VM areas will be allocated according to these | |
1200 | * groupings. If @ai->nr_groups is zero, a single group containing | |
1201 | * all units is assumed. | |
8d408b4b | 1202 | * |
38a6be52 TH |
1203 | * The caller should have mapped the first chunk at @base_addr and |
1204 | * copied static data to each unit. | |
fbf59bc9 | 1205 | * |
edcb4639 TH |
1206 | * If the first chunk ends up with both reserved and dynamic areas, it |
1207 | * is served by two chunks - one to serve the core static and reserved | |
1208 | * areas and the other for the dynamic area. They share the same vm | |
1209 | * and page map but uses different area allocation map to stay away | |
1210 | * from each other. The latter chunk is circulated in the chunk slots | |
1211 | * and available for dynamic allocation like any other chunks. | |
1212 | * | |
fbf59bc9 | 1213 | * RETURNS: |
fb435d52 | 1214 | * 0 on success, -errno on failure. |
fbf59bc9 | 1215 | */ |
fb435d52 TH |
1216 | int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, |
1217 | void *base_addr) | |
fbf59bc9 | 1218 | { |
635b75fc | 1219 | static char cpus_buf[4096] __initdata; |
099a19d9 TH |
1220 | static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; |
1221 | static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; | |
fd1e8a1f TH |
1222 | size_t dyn_size = ai->dyn_size; |
1223 | size_t size_sum = ai->static_size + ai->reserved_size + dyn_size; | |
edcb4639 | 1224 | struct pcpu_chunk *schunk, *dchunk = NULL; |
6563297c TH |
1225 | unsigned long *group_offsets; |
1226 | size_t *group_sizes; | |
fb435d52 | 1227 | unsigned long *unit_off; |
fbf59bc9 | 1228 | unsigned int cpu; |
fd1e8a1f TH |
1229 | int *unit_map; |
1230 | int group, unit, i; | |
fbf59bc9 | 1231 | |
635b75fc TH |
1232 | cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask); |
1233 | ||
1234 | #define PCPU_SETUP_BUG_ON(cond) do { \ | |
1235 | if (unlikely(cond)) { \ | |
1236 | pr_emerg("PERCPU: failed to initialize, %s", #cond); \ | |
1237 | pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \ | |
1238 | pcpu_dump_alloc_info(KERN_EMERG, ai); \ | |
1239 | BUG(); \ | |
1240 | } \ | |
1241 | } while (0) | |
1242 | ||
2f39e637 | 1243 | /* sanity checks */ |
635b75fc | 1244 | PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); |
bbddff05 | 1245 | #ifdef CONFIG_SMP |
635b75fc | 1246 | PCPU_SETUP_BUG_ON(!ai->static_size); |
0415b00d | 1247 | PCPU_SETUP_BUG_ON((unsigned long)__per_cpu_start & ~PAGE_MASK); |
bbddff05 | 1248 | #endif |
635b75fc | 1249 | PCPU_SETUP_BUG_ON(!base_addr); |
0415b00d | 1250 | PCPU_SETUP_BUG_ON((unsigned long)base_addr & ~PAGE_MASK); |
635b75fc TH |
1251 | PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); |
1252 | PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK); | |
1253 | PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); | |
099a19d9 | 1254 | PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE); |
9f645532 | 1255 | PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); |
8d408b4b | 1256 | |
6563297c | 1257 | /* process group information and build config tables accordingly */ |
999c17e3 SS |
1258 | group_offsets = memblock_virt_alloc(ai->nr_groups * |
1259 | sizeof(group_offsets[0]), 0); | |
1260 | group_sizes = memblock_virt_alloc(ai->nr_groups * | |
1261 | sizeof(group_sizes[0]), 0); | |
1262 | unit_map = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_map[0]), 0); | |
1263 | unit_off = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_off[0]), 0); | |
2f39e637 | 1264 | |
fd1e8a1f | 1265 | for (cpu = 0; cpu < nr_cpu_ids; cpu++) |
ffe0d5a5 | 1266 | unit_map[cpu] = UINT_MAX; |
a855b84c TH |
1267 | |
1268 | pcpu_low_unit_cpu = NR_CPUS; | |
1269 | pcpu_high_unit_cpu = NR_CPUS; | |
2f39e637 | 1270 | |
fd1e8a1f TH |
1271 | for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { |
1272 | const struct pcpu_group_info *gi = &ai->groups[group]; | |
2f39e637 | 1273 | |
6563297c TH |
1274 | group_offsets[group] = gi->base_offset; |
1275 | group_sizes[group] = gi->nr_units * ai->unit_size; | |
1276 | ||
fd1e8a1f TH |
1277 | for (i = 0; i < gi->nr_units; i++) { |
1278 | cpu = gi->cpu_map[i]; | |
1279 | if (cpu == NR_CPUS) | |
1280 | continue; | |
8d408b4b | 1281 | |
635b75fc TH |
1282 | PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids); |
1283 | PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); | |
1284 | PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); | |
fbf59bc9 | 1285 | |
fd1e8a1f | 1286 | unit_map[cpu] = unit + i; |
fb435d52 TH |
1287 | unit_off[cpu] = gi->base_offset + i * ai->unit_size; |
1288 | ||
a855b84c TH |
1289 | /* determine low/high unit_cpu */ |
1290 | if (pcpu_low_unit_cpu == NR_CPUS || | |
1291 | unit_off[cpu] < unit_off[pcpu_low_unit_cpu]) | |
1292 | pcpu_low_unit_cpu = cpu; | |
1293 | if (pcpu_high_unit_cpu == NR_CPUS || | |
1294 | unit_off[cpu] > unit_off[pcpu_high_unit_cpu]) | |
1295 | pcpu_high_unit_cpu = cpu; | |
fd1e8a1f | 1296 | } |
2f39e637 | 1297 | } |
fd1e8a1f TH |
1298 | pcpu_nr_units = unit; |
1299 | ||
1300 | for_each_possible_cpu(cpu) | |
635b75fc TH |
1301 | PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); |
1302 | ||
1303 | /* we're done parsing the input, undefine BUG macro and dump config */ | |
1304 | #undef PCPU_SETUP_BUG_ON | |
bcbea798 | 1305 | pcpu_dump_alloc_info(KERN_DEBUG, ai); |
fd1e8a1f | 1306 | |
6563297c TH |
1307 | pcpu_nr_groups = ai->nr_groups; |
1308 | pcpu_group_offsets = group_offsets; | |
1309 | pcpu_group_sizes = group_sizes; | |
fd1e8a1f | 1310 | pcpu_unit_map = unit_map; |
fb435d52 | 1311 | pcpu_unit_offsets = unit_off; |
2f39e637 TH |
1312 | |
1313 | /* determine basic parameters */ | |
fd1e8a1f | 1314 | pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; |
d9b55eeb | 1315 | pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; |
6563297c | 1316 | pcpu_atom_size = ai->atom_size; |
ce3141a2 TH |
1317 | pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + |
1318 | BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); | |
cafe8816 | 1319 | |
d9b55eeb TH |
1320 | /* |
1321 | * Allocate chunk slots. The additional last slot is for | |
1322 | * empty chunks. | |
1323 | */ | |
1324 | pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; | |
999c17e3 SS |
1325 | pcpu_slot = memblock_virt_alloc( |
1326 | pcpu_nr_slots * sizeof(pcpu_slot[0]), 0); | |
fbf59bc9 TH |
1327 | for (i = 0; i < pcpu_nr_slots; i++) |
1328 | INIT_LIST_HEAD(&pcpu_slot[i]); | |
1329 | ||
edcb4639 TH |
1330 | /* |
1331 | * Initialize static chunk. If reserved_size is zero, the | |
1332 | * static chunk covers static area + dynamic allocation area | |
1333 | * in the first chunk. If reserved_size is not zero, it | |
1334 | * covers static area + reserved area (mostly used for module | |
1335 | * static percpu allocation). | |
1336 | */ | |
999c17e3 | 1337 | schunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0); |
2441d15c | 1338 | INIT_LIST_HEAD(&schunk->list); |
bba174f5 | 1339 | schunk->base_addr = base_addr; |
61ace7fa TH |
1340 | schunk->map = smap; |
1341 | schunk->map_alloc = ARRAY_SIZE(smap); | |
38a6be52 | 1342 | schunk->immutable = true; |
ce3141a2 | 1343 | bitmap_fill(schunk->populated, pcpu_unit_pages); |
edcb4639 | 1344 | |
fd1e8a1f TH |
1345 | if (ai->reserved_size) { |
1346 | schunk->free_size = ai->reserved_size; | |
ae9e6bc9 | 1347 | pcpu_reserved_chunk = schunk; |
fd1e8a1f | 1348 | pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size; |
edcb4639 TH |
1349 | } else { |
1350 | schunk->free_size = dyn_size; | |
1351 | dyn_size = 0; /* dynamic area covered */ | |
1352 | } | |
2441d15c | 1353 | schunk->contig_hint = schunk->free_size; |
fbf59bc9 | 1354 | |
723ad1d9 AV |
1355 | schunk->map[0] = 1; |
1356 | schunk->map[1] = ai->static_size; | |
1357 | schunk->map_used = 1; | |
61ace7fa | 1358 | if (schunk->free_size) |
723ad1d9 AV |
1359 | schunk->map[++schunk->map_used] = 1 | (ai->static_size + schunk->free_size); |
1360 | else | |
1361 | schunk->map[1] |= 1; | |
61ace7fa | 1362 | |
edcb4639 TH |
1363 | /* init dynamic chunk if necessary */ |
1364 | if (dyn_size) { | |
999c17e3 | 1365 | dchunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0); |
edcb4639 | 1366 | INIT_LIST_HEAD(&dchunk->list); |
bba174f5 | 1367 | dchunk->base_addr = base_addr; |
edcb4639 TH |
1368 | dchunk->map = dmap; |
1369 | dchunk->map_alloc = ARRAY_SIZE(dmap); | |
38a6be52 | 1370 | dchunk->immutable = true; |
ce3141a2 | 1371 | bitmap_fill(dchunk->populated, pcpu_unit_pages); |
edcb4639 TH |
1372 | |
1373 | dchunk->contig_hint = dchunk->free_size = dyn_size; | |
723ad1d9 AV |
1374 | dchunk->map[0] = 1; |
1375 | dchunk->map[1] = pcpu_reserved_chunk_limit; | |
1376 | dchunk->map[2] = (pcpu_reserved_chunk_limit + dchunk->free_size) | 1; | |
1377 | dchunk->map_used = 2; | |
edcb4639 TH |
1378 | } |
1379 | ||
2441d15c | 1380 | /* link the first chunk in */ |
ae9e6bc9 TH |
1381 | pcpu_first_chunk = dchunk ?: schunk; |
1382 | pcpu_chunk_relocate(pcpu_first_chunk, -1); | |
fbf59bc9 TH |
1383 | |
1384 | /* we're done */ | |
bba174f5 | 1385 | pcpu_base_addr = base_addr; |
fb435d52 | 1386 | return 0; |
fbf59bc9 | 1387 | } |
66c3a757 | 1388 | |
bbddff05 TH |
1389 | #ifdef CONFIG_SMP |
1390 | ||
17f3609c | 1391 | const char * const pcpu_fc_names[PCPU_FC_NR] __initconst = { |
f58dc01b TH |
1392 | [PCPU_FC_AUTO] = "auto", |
1393 | [PCPU_FC_EMBED] = "embed", | |
1394 | [PCPU_FC_PAGE] = "page", | |
f58dc01b | 1395 | }; |
66c3a757 | 1396 | |
f58dc01b | 1397 | enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; |
66c3a757 | 1398 | |
f58dc01b TH |
1399 | static int __init percpu_alloc_setup(char *str) |
1400 | { | |
5479c78a CG |
1401 | if (!str) |
1402 | return -EINVAL; | |
1403 | ||
f58dc01b TH |
1404 | if (0) |
1405 | /* nada */; | |
1406 | #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK | |
1407 | else if (!strcmp(str, "embed")) | |
1408 | pcpu_chosen_fc = PCPU_FC_EMBED; | |
1409 | #endif | |
1410 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK | |
1411 | else if (!strcmp(str, "page")) | |
1412 | pcpu_chosen_fc = PCPU_FC_PAGE; | |
f58dc01b TH |
1413 | #endif |
1414 | else | |
1415 | pr_warning("PERCPU: unknown allocator %s specified\n", str); | |
66c3a757 | 1416 | |
f58dc01b | 1417 | return 0; |
66c3a757 | 1418 | } |
f58dc01b | 1419 | early_param("percpu_alloc", percpu_alloc_setup); |
66c3a757 | 1420 | |
3c9a024f TH |
1421 | /* |
1422 | * pcpu_embed_first_chunk() is used by the generic percpu setup. | |
1423 | * Build it if needed by the arch config or the generic setup is going | |
1424 | * to be used. | |
1425 | */ | |
08fc4580 TH |
1426 | #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ |
1427 | !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) | |
3c9a024f TH |
1428 | #define BUILD_EMBED_FIRST_CHUNK |
1429 | #endif | |
1430 | ||
1431 | /* build pcpu_page_first_chunk() iff needed by the arch config */ | |
1432 | #if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) | |
1433 | #define BUILD_PAGE_FIRST_CHUNK | |
1434 | #endif | |
1435 | ||
1436 | /* pcpu_build_alloc_info() is used by both embed and page first chunk */ | |
1437 | #if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK) | |
1438 | /** | |
1439 | * pcpu_build_alloc_info - build alloc_info considering distances between CPUs | |
1440 | * @reserved_size: the size of reserved percpu area in bytes | |
1441 | * @dyn_size: minimum free size for dynamic allocation in bytes | |
1442 | * @atom_size: allocation atom size | |
1443 | * @cpu_distance_fn: callback to determine distance between cpus, optional | |
1444 | * | |
1445 | * This function determines grouping of units, their mappings to cpus | |
1446 | * and other parameters considering needed percpu size, allocation | |
1447 | * atom size and distances between CPUs. | |
1448 | * | |
1449 | * Groups are always mutliples of atom size and CPUs which are of | |
1450 | * LOCAL_DISTANCE both ways are grouped together and share space for | |
1451 | * units in the same group. The returned configuration is guaranteed | |
1452 | * to have CPUs on different nodes on different groups and >=75% usage | |
1453 | * of allocated virtual address space. | |
1454 | * | |
1455 | * RETURNS: | |
1456 | * On success, pointer to the new allocation_info is returned. On | |
1457 | * failure, ERR_PTR value is returned. | |
1458 | */ | |
1459 | static struct pcpu_alloc_info * __init pcpu_build_alloc_info( | |
1460 | size_t reserved_size, size_t dyn_size, | |
1461 | size_t atom_size, | |
1462 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn) | |
1463 | { | |
1464 | static int group_map[NR_CPUS] __initdata; | |
1465 | static int group_cnt[NR_CPUS] __initdata; | |
1466 | const size_t static_size = __per_cpu_end - __per_cpu_start; | |
1467 | int nr_groups = 1, nr_units = 0; | |
1468 | size_t size_sum, min_unit_size, alloc_size; | |
1469 | int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ | |
1470 | int last_allocs, group, unit; | |
1471 | unsigned int cpu, tcpu; | |
1472 | struct pcpu_alloc_info *ai; | |
1473 | unsigned int *cpu_map; | |
1474 | ||
1475 | /* this function may be called multiple times */ | |
1476 | memset(group_map, 0, sizeof(group_map)); | |
1477 | memset(group_cnt, 0, sizeof(group_cnt)); | |
1478 | ||
1479 | /* calculate size_sum and ensure dyn_size is enough for early alloc */ | |
1480 | size_sum = PFN_ALIGN(static_size + reserved_size + | |
1481 | max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE)); | |
1482 | dyn_size = size_sum - static_size - reserved_size; | |
1483 | ||
1484 | /* | |
1485 | * Determine min_unit_size, alloc_size and max_upa such that | |
1486 | * alloc_size is multiple of atom_size and is the smallest | |
25985edc | 1487 | * which can accommodate 4k aligned segments which are equal to |
3c9a024f TH |
1488 | * or larger than min_unit_size. |
1489 | */ | |
1490 | min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); | |
1491 | ||
1492 | alloc_size = roundup(min_unit_size, atom_size); | |
1493 | upa = alloc_size / min_unit_size; | |
1494 | while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) | |
1495 | upa--; | |
1496 | max_upa = upa; | |
1497 | ||
1498 | /* group cpus according to their proximity */ | |
1499 | for_each_possible_cpu(cpu) { | |
1500 | group = 0; | |
1501 | next_group: | |
1502 | for_each_possible_cpu(tcpu) { | |
1503 | if (cpu == tcpu) | |
1504 | break; | |
1505 | if (group_map[tcpu] == group && cpu_distance_fn && | |
1506 | (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || | |
1507 | cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { | |
1508 | group++; | |
1509 | nr_groups = max(nr_groups, group + 1); | |
1510 | goto next_group; | |
1511 | } | |
1512 | } | |
1513 | group_map[cpu] = group; | |
1514 | group_cnt[group]++; | |
1515 | } | |
1516 | ||
1517 | /* | |
1518 | * Expand unit size until address space usage goes over 75% | |
1519 | * and then as much as possible without using more address | |
1520 | * space. | |
1521 | */ | |
1522 | last_allocs = INT_MAX; | |
1523 | for (upa = max_upa; upa; upa--) { | |
1524 | int allocs = 0, wasted = 0; | |
1525 | ||
1526 | if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) | |
1527 | continue; | |
1528 | ||
1529 | for (group = 0; group < nr_groups; group++) { | |
1530 | int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); | |
1531 | allocs += this_allocs; | |
1532 | wasted += this_allocs * upa - group_cnt[group]; | |
1533 | } | |
1534 | ||
1535 | /* | |
1536 | * Don't accept if wastage is over 1/3. The | |
1537 | * greater-than comparison ensures upa==1 always | |
1538 | * passes the following check. | |
1539 | */ | |
1540 | if (wasted > num_possible_cpus() / 3) | |
1541 | continue; | |
1542 | ||
1543 | /* and then don't consume more memory */ | |
1544 | if (allocs > last_allocs) | |
1545 | break; | |
1546 | last_allocs = allocs; | |
1547 | best_upa = upa; | |
1548 | } | |
1549 | upa = best_upa; | |
1550 | ||
1551 | /* allocate and fill alloc_info */ | |
1552 | for (group = 0; group < nr_groups; group++) | |
1553 | nr_units += roundup(group_cnt[group], upa); | |
1554 | ||
1555 | ai = pcpu_alloc_alloc_info(nr_groups, nr_units); | |
1556 | if (!ai) | |
1557 | return ERR_PTR(-ENOMEM); | |
1558 | cpu_map = ai->groups[0].cpu_map; | |
1559 | ||
1560 | for (group = 0; group < nr_groups; group++) { | |
1561 | ai->groups[group].cpu_map = cpu_map; | |
1562 | cpu_map += roundup(group_cnt[group], upa); | |
1563 | } | |
1564 | ||
1565 | ai->static_size = static_size; | |
1566 | ai->reserved_size = reserved_size; | |
1567 | ai->dyn_size = dyn_size; | |
1568 | ai->unit_size = alloc_size / upa; | |
1569 | ai->atom_size = atom_size; | |
1570 | ai->alloc_size = alloc_size; | |
1571 | ||
1572 | for (group = 0, unit = 0; group_cnt[group]; group++) { | |
1573 | struct pcpu_group_info *gi = &ai->groups[group]; | |
1574 | ||
1575 | /* | |
1576 | * Initialize base_offset as if all groups are located | |
1577 | * back-to-back. The caller should update this to | |
1578 | * reflect actual allocation. | |
1579 | */ | |
1580 | gi->base_offset = unit * ai->unit_size; | |
1581 | ||
1582 | for_each_possible_cpu(cpu) | |
1583 | if (group_map[cpu] == group) | |
1584 | gi->cpu_map[gi->nr_units++] = cpu; | |
1585 | gi->nr_units = roundup(gi->nr_units, upa); | |
1586 | unit += gi->nr_units; | |
1587 | } | |
1588 | BUG_ON(unit != nr_units); | |
1589 | ||
1590 | return ai; | |
1591 | } | |
1592 | #endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */ | |
1593 | ||
1594 | #if defined(BUILD_EMBED_FIRST_CHUNK) | |
66c3a757 TH |
1595 | /** |
1596 | * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem | |
66c3a757 | 1597 | * @reserved_size: the size of reserved percpu area in bytes |
4ba6ce25 | 1598 | * @dyn_size: minimum free size for dynamic allocation in bytes |
c8826dd5 TH |
1599 | * @atom_size: allocation atom size |
1600 | * @cpu_distance_fn: callback to determine distance between cpus, optional | |
1601 | * @alloc_fn: function to allocate percpu page | |
25985edc | 1602 | * @free_fn: function to free percpu page |
66c3a757 TH |
1603 | * |
1604 | * This is a helper to ease setting up embedded first percpu chunk and | |
1605 | * can be called where pcpu_setup_first_chunk() is expected. | |
1606 | * | |
1607 | * If this function is used to setup the first chunk, it is allocated | |
c8826dd5 TH |
1608 | * by calling @alloc_fn and used as-is without being mapped into |
1609 | * vmalloc area. Allocations are always whole multiples of @atom_size | |
1610 | * aligned to @atom_size. | |
1611 | * | |
1612 | * This enables the first chunk to piggy back on the linear physical | |
1613 | * mapping which often uses larger page size. Please note that this | |
1614 | * can result in very sparse cpu->unit mapping on NUMA machines thus | |
1615 | * requiring large vmalloc address space. Don't use this allocator if | |
1616 | * vmalloc space is not orders of magnitude larger than distances | |
1617 | * between node memory addresses (ie. 32bit NUMA machines). | |
66c3a757 | 1618 | * |
4ba6ce25 | 1619 | * @dyn_size specifies the minimum dynamic area size. |
66c3a757 TH |
1620 | * |
1621 | * If the needed size is smaller than the minimum or specified unit | |
c8826dd5 | 1622 | * size, the leftover is returned using @free_fn. |
66c3a757 TH |
1623 | * |
1624 | * RETURNS: | |
fb435d52 | 1625 | * 0 on success, -errno on failure. |
66c3a757 | 1626 | */ |
4ba6ce25 | 1627 | int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, |
c8826dd5 TH |
1628 | size_t atom_size, |
1629 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn, | |
1630 | pcpu_fc_alloc_fn_t alloc_fn, | |
1631 | pcpu_fc_free_fn_t free_fn) | |
66c3a757 | 1632 | { |
c8826dd5 TH |
1633 | void *base = (void *)ULONG_MAX; |
1634 | void **areas = NULL; | |
fd1e8a1f | 1635 | struct pcpu_alloc_info *ai; |
6ea529a2 | 1636 | size_t size_sum, areas_size, max_distance; |
c8826dd5 | 1637 | int group, i, rc; |
66c3a757 | 1638 | |
c8826dd5 TH |
1639 | ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, |
1640 | cpu_distance_fn); | |
fd1e8a1f TH |
1641 | if (IS_ERR(ai)) |
1642 | return PTR_ERR(ai); | |
66c3a757 | 1643 | |
fd1e8a1f | 1644 | size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; |
c8826dd5 | 1645 | areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); |
fa8a7094 | 1646 | |
999c17e3 | 1647 | areas = memblock_virt_alloc_nopanic(areas_size, 0); |
c8826dd5 | 1648 | if (!areas) { |
fb435d52 | 1649 | rc = -ENOMEM; |
c8826dd5 | 1650 | goto out_free; |
fa8a7094 | 1651 | } |
66c3a757 | 1652 | |
c8826dd5 TH |
1653 | /* allocate, copy and determine base address */ |
1654 | for (group = 0; group < ai->nr_groups; group++) { | |
1655 | struct pcpu_group_info *gi = &ai->groups[group]; | |
1656 | unsigned int cpu = NR_CPUS; | |
1657 | void *ptr; | |
1658 | ||
1659 | for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) | |
1660 | cpu = gi->cpu_map[i]; | |
1661 | BUG_ON(cpu == NR_CPUS); | |
1662 | ||
1663 | /* allocate space for the whole group */ | |
1664 | ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); | |
1665 | if (!ptr) { | |
1666 | rc = -ENOMEM; | |
1667 | goto out_free_areas; | |
1668 | } | |
f528f0b8 CM |
1669 | /* kmemleak tracks the percpu allocations separately */ |
1670 | kmemleak_free(ptr); | |
c8826dd5 | 1671 | areas[group] = ptr; |
fd1e8a1f | 1672 | |
c8826dd5 | 1673 | base = min(ptr, base); |
42b64281 TH |
1674 | } |
1675 | ||
1676 | /* | |
1677 | * Copy data and free unused parts. This should happen after all | |
1678 | * allocations are complete; otherwise, we may end up with | |
1679 | * overlapping groups. | |
1680 | */ | |
1681 | for (group = 0; group < ai->nr_groups; group++) { | |
1682 | struct pcpu_group_info *gi = &ai->groups[group]; | |
1683 | void *ptr = areas[group]; | |
c8826dd5 TH |
1684 | |
1685 | for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { | |
1686 | if (gi->cpu_map[i] == NR_CPUS) { | |
1687 | /* unused unit, free whole */ | |
1688 | free_fn(ptr, ai->unit_size); | |
1689 | continue; | |
1690 | } | |
1691 | /* copy and return the unused part */ | |
1692 | memcpy(ptr, __per_cpu_load, ai->static_size); | |
1693 | free_fn(ptr + size_sum, ai->unit_size - size_sum); | |
1694 | } | |
fa8a7094 | 1695 | } |
66c3a757 | 1696 | |
c8826dd5 | 1697 | /* base address is now known, determine group base offsets */ |
6ea529a2 TH |
1698 | max_distance = 0; |
1699 | for (group = 0; group < ai->nr_groups; group++) { | |
c8826dd5 | 1700 | ai->groups[group].base_offset = areas[group] - base; |
1a0c3298 TH |
1701 | max_distance = max_t(size_t, max_distance, |
1702 | ai->groups[group].base_offset); | |
6ea529a2 TH |
1703 | } |
1704 | max_distance += ai->unit_size; | |
1705 | ||
1706 | /* warn if maximum distance is further than 75% of vmalloc space */ | |
8a092171 | 1707 | if (max_distance > VMALLOC_TOTAL * 3 / 4) { |
1a0c3298 | 1708 | pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc " |
787e5b06 | 1709 | "space 0x%lx\n", max_distance, |
8a092171 | 1710 | VMALLOC_TOTAL); |
6ea529a2 TH |
1711 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK |
1712 | /* and fail if we have fallback */ | |
1713 | rc = -EINVAL; | |
1714 | goto out_free; | |
1715 | #endif | |
1716 | } | |
c8826dd5 | 1717 | |
004018e2 | 1718 | pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", |
fd1e8a1f TH |
1719 | PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, |
1720 | ai->dyn_size, ai->unit_size); | |
d4b95f80 | 1721 | |
fb435d52 | 1722 | rc = pcpu_setup_first_chunk(ai, base); |
c8826dd5 TH |
1723 | goto out_free; |
1724 | ||
1725 | out_free_areas: | |
1726 | for (group = 0; group < ai->nr_groups; group++) | |
f851c8d8 MH |
1727 | if (areas[group]) |
1728 | free_fn(areas[group], | |
1729 | ai->groups[group].nr_units * ai->unit_size); | |
c8826dd5 | 1730 | out_free: |
fd1e8a1f | 1731 | pcpu_free_alloc_info(ai); |
c8826dd5 | 1732 | if (areas) |
999c17e3 | 1733 | memblock_free_early(__pa(areas), areas_size); |
fb435d52 | 1734 | return rc; |
d4b95f80 | 1735 | } |
3c9a024f | 1736 | #endif /* BUILD_EMBED_FIRST_CHUNK */ |
d4b95f80 | 1737 | |
3c9a024f | 1738 | #ifdef BUILD_PAGE_FIRST_CHUNK |
d4b95f80 | 1739 | /** |
00ae4064 | 1740 | * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages |
d4b95f80 TH |
1741 | * @reserved_size: the size of reserved percpu area in bytes |
1742 | * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE | |
25985edc | 1743 | * @free_fn: function to free percpu page, always called with PAGE_SIZE |
d4b95f80 TH |
1744 | * @populate_pte_fn: function to populate pte |
1745 | * | |
00ae4064 TH |
1746 | * This is a helper to ease setting up page-remapped first percpu |
1747 | * chunk and can be called where pcpu_setup_first_chunk() is expected. | |
d4b95f80 TH |
1748 | * |
1749 | * This is the basic allocator. Static percpu area is allocated | |
1750 | * page-by-page into vmalloc area. | |
1751 | * | |
1752 | * RETURNS: | |
fb435d52 | 1753 | * 0 on success, -errno on failure. |
d4b95f80 | 1754 | */ |
fb435d52 TH |
1755 | int __init pcpu_page_first_chunk(size_t reserved_size, |
1756 | pcpu_fc_alloc_fn_t alloc_fn, | |
1757 | pcpu_fc_free_fn_t free_fn, | |
1758 | pcpu_fc_populate_pte_fn_t populate_pte_fn) | |
d4b95f80 | 1759 | { |
8f05a6a6 | 1760 | static struct vm_struct vm; |
fd1e8a1f | 1761 | struct pcpu_alloc_info *ai; |
00ae4064 | 1762 | char psize_str[16]; |
ce3141a2 | 1763 | int unit_pages; |
d4b95f80 | 1764 | size_t pages_size; |
ce3141a2 | 1765 | struct page **pages; |
fb435d52 | 1766 | int unit, i, j, rc; |
d4b95f80 | 1767 | |
00ae4064 TH |
1768 | snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); |
1769 | ||
4ba6ce25 | 1770 | ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL); |
fd1e8a1f TH |
1771 | if (IS_ERR(ai)) |
1772 | return PTR_ERR(ai); | |
1773 | BUG_ON(ai->nr_groups != 1); | |
1774 | BUG_ON(ai->groups[0].nr_units != num_possible_cpus()); | |
1775 | ||
1776 | unit_pages = ai->unit_size >> PAGE_SHIFT; | |
d4b95f80 TH |
1777 | |
1778 | /* unaligned allocations can't be freed, round up to page size */ | |
fd1e8a1f TH |
1779 | pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * |
1780 | sizeof(pages[0])); | |
999c17e3 | 1781 | pages = memblock_virt_alloc(pages_size, 0); |
d4b95f80 | 1782 | |
8f05a6a6 | 1783 | /* allocate pages */ |
d4b95f80 | 1784 | j = 0; |
fd1e8a1f | 1785 | for (unit = 0; unit < num_possible_cpus(); unit++) |
ce3141a2 | 1786 | for (i = 0; i < unit_pages; i++) { |
fd1e8a1f | 1787 | unsigned int cpu = ai->groups[0].cpu_map[unit]; |
d4b95f80 TH |
1788 | void *ptr; |
1789 | ||
3cbc8565 | 1790 | ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); |
d4b95f80 | 1791 | if (!ptr) { |
00ae4064 TH |
1792 | pr_warning("PERCPU: failed to allocate %s page " |
1793 | "for cpu%u\n", psize_str, cpu); | |
d4b95f80 TH |
1794 | goto enomem; |
1795 | } | |
f528f0b8 CM |
1796 | /* kmemleak tracks the percpu allocations separately */ |
1797 | kmemleak_free(ptr); | |
ce3141a2 | 1798 | pages[j++] = virt_to_page(ptr); |
d4b95f80 TH |
1799 | } |
1800 | ||
8f05a6a6 TH |
1801 | /* allocate vm area, map the pages and copy static data */ |
1802 | vm.flags = VM_ALLOC; | |
fd1e8a1f | 1803 | vm.size = num_possible_cpus() * ai->unit_size; |
8f05a6a6 TH |
1804 | vm_area_register_early(&vm, PAGE_SIZE); |
1805 | ||
fd1e8a1f | 1806 | for (unit = 0; unit < num_possible_cpus(); unit++) { |
1d9d3257 | 1807 | unsigned long unit_addr = |
fd1e8a1f | 1808 | (unsigned long)vm.addr + unit * ai->unit_size; |
8f05a6a6 | 1809 | |
ce3141a2 | 1810 | for (i = 0; i < unit_pages; i++) |
8f05a6a6 TH |
1811 | populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); |
1812 | ||
1813 | /* pte already populated, the following shouldn't fail */ | |
fb435d52 TH |
1814 | rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], |
1815 | unit_pages); | |
1816 | if (rc < 0) | |
1817 | panic("failed to map percpu area, err=%d\n", rc); | |
66c3a757 | 1818 | |
8f05a6a6 TH |
1819 | /* |
1820 | * FIXME: Archs with virtual cache should flush local | |
1821 | * cache for the linear mapping here - something | |
1822 | * equivalent to flush_cache_vmap() on the local cpu. | |
1823 | * flush_cache_vmap() can't be used as most supporting | |
1824 | * data structures are not set up yet. | |
1825 | */ | |
1826 | ||
1827 | /* copy static data */ | |
fd1e8a1f | 1828 | memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); |
66c3a757 TH |
1829 | } |
1830 | ||
1831 | /* we're ready, commit */ | |
1d9d3257 | 1832 | pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n", |
fd1e8a1f TH |
1833 | unit_pages, psize_str, vm.addr, ai->static_size, |
1834 | ai->reserved_size, ai->dyn_size); | |
d4b95f80 | 1835 | |
fb435d52 | 1836 | rc = pcpu_setup_first_chunk(ai, vm.addr); |
d4b95f80 TH |
1837 | goto out_free_ar; |
1838 | ||
1839 | enomem: | |
1840 | while (--j >= 0) | |
ce3141a2 | 1841 | free_fn(page_address(pages[j]), PAGE_SIZE); |
fb435d52 | 1842 | rc = -ENOMEM; |
d4b95f80 | 1843 | out_free_ar: |
999c17e3 | 1844 | memblock_free_early(__pa(pages), pages_size); |
fd1e8a1f | 1845 | pcpu_free_alloc_info(ai); |
fb435d52 | 1846 | return rc; |
d4b95f80 | 1847 | } |
3c9a024f | 1848 | #endif /* BUILD_PAGE_FIRST_CHUNK */ |
d4b95f80 | 1849 | |
bbddff05 | 1850 | #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA |
e74e3962 | 1851 | /* |
bbddff05 | 1852 | * Generic SMP percpu area setup. |
e74e3962 TH |
1853 | * |
1854 | * The embedding helper is used because its behavior closely resembles | |
1855 | * the original non-dynamic generic percpu area setup. This is | |
1856 | * important because many archs have addressing restrictions and might | |
1857 | * fail if the percpu area is located far away from the previous | |
1858 | * location. As an added bonus, in non-NUMA cases, embedding is | |
1859 | * generally a good idea TLB-wise because percpu area can piggy back | |
1860 | * on the physical linear memory mapping which uses large page | |
1861 | * mappings on applicable archs. | |
1862 | */ | |
e74e3962 TH |
1863 | unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; |
1864 | EXPORT_SYMBOL(__per_cpu_offset); | |
1865 | ||
c8826dd5 TH |
1866 | static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, |
1867 | size_t align) | |
1868 | { | |
999c17e3 SS |
1869 | return memblock_virt_alloc_from_nopanic( |
1870 | size, align, __pa(MAX_DMA_ADDRESS)); | |
c8826dd5 | 1871 | } |
66c3a757 | 1872 | |
c8826dd5 TH |
1873 | static void __init pcpu_dfl_fc_free(void *ptr, size_t size) |
1874 | { | |
999c17e3 | 1875 | memblock_free_early(__pa(ptr), size); |
c8826dd5 TH |
1876 | } |
1877 | ||
e74e3962 TH |
1878 | void __init setup_per_cpu_areas(void) |
1879 | { | |
e74e3962 TH |
1880 | unsigned long delta; |
1881 | unsigned int cpu; | |
fb435d52 | 1882 | int rc; |
e74e3962 TH |
1883 | |
1884 | /* | |
1885 | * Always reserve area for module percpu variables. That's | |
1886 | * what the legacy allocator did. | |
1887 | */ | |
fb435d52 | 1888 | rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, |
c8826dd5 TH |
1889 | PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, |
1890 | pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); | |
fb435d52 | 1891 | if (rc < 0) |
bbddff05 | 1892 | panic("Failed to initialize percpu areas."); |
e74e3962 TH |
1893 | |
1894 | delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; | |
1895 | for_each_possible_cpu(cpu) | |
fb435d52 | 1896 | __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; |
66c3a757 | 1897 | } |
bbddff05 TH |
1898 | #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ |
1899 | ||
1900 | #else /* CONFIG_SMP */ | |
1901 | ||
1902 | /* | |
1903 | * UP percpu area setup. | |
1904 | * | |
1905 | * UP always uses km-based percpu allocator with identity mapping. | |
1906 | * Static percpu variables are indistinguishable from the usual static | |
1907 | * variables and don't require any special preparation. | |
1908 | */ | |
1909 | void __init setup_per_cpu_areas(void) | |
1910 | { | |
1911 | const size_t unit_size = | |
1912 | roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE, | |
1913 | PERCPU_DYNAMIC_RESERVE)); | |
1914 | struct pcpu_alloc_info *ai; | |
1915 | void *fc; | |
1916 | ||
1917 | ai = pcpu_alloc_alloc_info(1, 1); | |
999c17e3 SS |
1918 | fc = memblock_virt_alloc_from_nopanic(unit_size, |
1919 | PAGE_SIZE, | |
1920 | __pa(MAX_DMA_ADDRESS)); | |
bbddff05 TH |
1921 | if (!ai || !fc) |
1922 | panic("Failed to allocate memory for percpu areas."); | |
100d13c3 CM |
1923 | /* kmemleak tracks the percpu allocations separately */ |
1924 | kmemleak_free(fc); | |
bbddff05 TH |
1925 | |
1926 | ai->dyn_size = unit_size; | |
1927 | ai->unit_size = unit_size; | |
1928 | ai->atom_size = unit_size; | |
1929 | ai->alloc_size = unit_size; | |
1930 | ai->groups[0].nr_units = 1; | |
1931 | ai->groups[0].cpu_map[0] = 0; | |
1932 | ||
1933 | if (pcpu_setup_first_chunk(ai, fc) < 0) | |
1934 | panic("Failed to initialize percpu areas."); | |
1935 | } | |
1936 | ||
1937 | #endif /* CONFIG_SMP */ | |
099a19d9 TH |
1938 | |
1939 | /* | |
1940 | * First and reserved chunks are initialized with temporary allocation | |
1941 | * map in initdata so that they can be used before slab is online. | |
1942 | * This function is called after slab is brought up and replaces those | |
1943 | * with properly allocated maps. | |
1944 | */ | |
1945 | void __init percpu_init_late(void) | |
1946 | { | |
1947 | struct pcpu_chunk *target_chunks[] = | |
1948 | { pcpu_first_chunk, pcpu_reserved_chunk, NULL }; | |
1949 | struct pcpu_chunk *chunk; | |
1950 | unsigned long flags; | |
1951 | int i; | |
1952 | ||
1953 | for (i = 0; (chunk = target_chunks[i]); i++) { | |
1954 | int *map; | |
1955 | const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]); | |
1956 | ||
1957 | BUILD_BUG_ON(size > PAGE_SIZE); | |
1958 | ||
90459ce0 | 1959 | map = pcpu_mem_zalloc(size); |
099a19d9 TH |
1960 | BUG_ON(!map); |
1961 | ||
1962 | spin_lock_irqsave(&pcpu_lock, flags); | |
1963 | memcpy(map, chunk->map, size); | |
1964 | chunk->map = map; | |
1965 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
1966 | } | |
1967 | } |