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> |
fbf59bc9 TH |
70 | |
71 | #include <asm/cacheflush.h> | |
e0100983 | 72 | #include <asm/sections.h> |
fbf59bc9 | 73 | #include <asm/tlbflush.h> |
3b034b0d | 74 | #include <asm/io.h> |
fbf59bc9 | 75 | |
fbf59bc9 TH |
76 | #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ |
77 | #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ | |
78 | ||
bbddff05 | 79 | #ifdef CONFIG_SMP |
e0100983 TH |
80 | /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ |
81 | #ifndef __addr_to_pcpu_ptr | |
82 | #define __addr_to_pcpu_ptr(addr) \ | |
43cf38eb TH |
83 | (void __percpu *)((unsigned long)(addr) - \ |
84 | (unsigned long)pcpu_base_addr + \ | |
85 | (unsigned long)__per_cpu_start) | |
e0100983 TH |
86 | #endif |
87 | #ifndef __pcpu_ptr_to_addr | |
88 | #define __pcpu_ptr_to_addr(ptr) \ | |
43cf38eb TH |
89 | (void __force *)((unsigned long)(ptr) + \ |
90 | (unsigned long)pcpu_base_addr - \ | |
91 | (unsigned long)__per_cpu_start) | |
e0100983 | 92 | #endif |
bbddff05 TH |
93 | #else /* CONFIG_SMP */ |
94 | /* on UP, it's always identity mapped */ | |
95 | #define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr) | |
96 | #define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr) | |
97 | #endif /* CONFIG_SMP */ | |
e0100983 | 98 | |
fbf59bc9 TH |
99 | struct pcpu_chunk { |
100 | struct list_head list; /* linked to pcpu_slot lists */ | |
fbf59bc9 TH |
101 | int free_size; /* free bytes in the chunk */ |
102 | int contig_hint; /* max contiguous size hint */ | |
bba174f5 | 103 | void *base_addr; /* base address of this chunk */ |
fbf59bc9 TH |
104 | int map_used; /* # of map entries used */ |
105 | int map_alloc; /* # of map entries allocated */ | |
106 | int *map; /* allocation map */ | |
88999a89 | 107 | void *data; /* chunk data */ |
8d408b4b | 108 | bool immutable; /* no [de]population allowed */ |
ce3141a2 | 109 | unsigned long populated[]; /* populated bitmap */ |
fbf59bc9 TH |
110 | }; |
111 | ||
40150d37 TH |
112 | static int pcpu_unit_pages __read_mostly; |
113 | static int pcpu_unit_size __read_mostly; | |
2f39e637 | 114 | static int pcpu_nr_units __read_mostly; |
6563297c | 115 | static int pcpu_atom_size __read_mostly; |
40150d37 TH |
116 | static int pcpu_nr_slots __read_mostly; |
117 | static size_t pcpu_chunk_struct_size __read_mostly; | |
fbf59bc9 | 118 | |
2f39e637 TH |
119 | /* cpus with the lowest and highest unit numbers */ |
120 | static unsigned int pcpu_first_unit_cpu __read_mostly; | |
121 | static unsigned int pcpu_last_unit_cpu __read_mostly; | |
122 | ||
fbf59bc9 | 123 | /* the address of the first chunk which starts with the kernel static area */ |
40150d37 | 124 | void *pcpu_base_addr __read_mostly; |
fbf59bc9 TH |
125 | EXPORT_SYMBOL_GPL(pcpu_base_addr); |
126 | ||
fb435d52 TH |
127 | static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */ |
128 | const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */ | |
2f39e637 | 129 | |
6563297c TH |
130 | /* group information, used for vm allocation */ |
131 | static int pcpu_nr_groups __read_mostly; | |
132 | static const unsigned long *pcpu_group_offsets __read_mostly; | |
133 | static const size_t *pcpu_group_sizes __read_mostly; | |
134 | ||
ae9e6bc9 TH |
135 | /* |
136 | * The first chunk which always exists. Note that unlike other | |
137 | * chunks, this one can be allocated and mapped in several different | |
138 | * ways and thus often doesn't live in the vmalloc area. | |
139 | */ | |
140 | static struct pcpu_chunk *pcpu_first_chunk; | |
141 | ||
142 | /* | |
143 | * Optional reserved chunk. This chunk reserves part of the first | |
144 | * chunk and serves it for reserved allocations. The amount of | |
145 | * reserved offset is in pcpu_reserved_chunk_limit. When reserved | |
146 | * area doesn't exist, the following variables contain NULL and 0 | |
147 | * respectively. | |
148 | */ | |
edcb4639 | 149 | static struct pcpu_chunk *pcpu_reserved_chunk; |
edcb4639 TH |
150 | static int pcpu_reserved_chunk_limit; |
151 | ||
fbf59bc9 | 152 | /* |
ccea34b5 TH |
153 | * Synchronization rules. |
154 | * | |
155 | * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former | |
ce3141a2 TH |
156 | * protects allocation/reclaim paths, chunks, populated bitmap and |
157 | * vmalloc mapping. The latter is a spinlock and protects the index | |
158 | * data structures - chunk slots, chunks and area maps in chunks. | |
ccea34b5 TH |
159 | * |
160 | * During allocation, pcpu_alloc_mutex is kept locked all the time and | |
161 | * pcpu_lock is grabbed and released as necessary. All actual memory | |
403a91b1 JK |
162 | * allocations are done using GFP_KERNEL with pcpu_lock released. In |
163 | * general, percpu memory can't be allocated with irq off but | |
164 | * irqsave/restore are still used in alloc path so that it can be used | |
165 | * from early init path - sched_init() specifically. | |
ccea34b5 TH |
166 | * |
167 | * Free path accesses and alters only the index data structures, so it | |
168 | * can be safely called from atomic context. When memory needs to be | |
169 | * returned to the system, free path schedules reclaim_work which | |
170 | * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be | |
171 | * reclaimed, release both locks and frees the chunks. Note that it's | |
172 | * necessary to grab both locks to remove a chunk from circulation as | |
173 | * allocation path might be referencing the chunk with only | |
174 | * pcpu_alloc_mutex locked. | |
fbf59bc9 | 175 | */ |
ccea34b5 TH |
176 | static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */ |
177 | static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */ | |
fbf59bc9 | 178 | |
40150d37 | 179 | static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ |
fbf59bc9 | 180 | |
a56dbddf TH |
181 | /* reclaim work to release fully free chunks, scheduled from free path */ |
182 | static void pcpu_reclaim(struct work_struct *work); | |
183 | static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); | |
184 | ||
020ec653 TH |
185 | static bool pcpu_addr_in_first_chunk(void *addr) |
186 | { | |
187 | void *first_start = pcpu_first_chunk->base_addr; | |
188 | ||
189 | return addr >= first_start && addr < first_start + pcpu_unit_size; | |
190 | } | |
191 | ||
192 | static bool pcpu_addr_in_reserved_chunk(void *addr) | |
193 | { | |
194 | void *first_start = pcpu_first_chunk->base_addr; | |
195 | ||
196 | return addr >= first_start && | |
197 | addr < first_start + pcpu_reserved_chunk_limit; | |
198 | } | |
199 | ||
d9b55eeb | 200 | static int __pcpu_size_to_slot(int size) |
fbf59bc9 | 201 | { |
cae3aeb8 | 202 | int highbit = fls(size); /* size is in bytes */ |
fbf59bc9 TH |
203 | return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); |
204 | } | |
205 | ||
d9b55eeb TH |
206 | static int pcpu_size_to_slot(int size) |
207 | { | |
208 | if (size == pcpu_unit_size) | |
209 | return pcpu_nr_slots - 1; | |
210 | return __pcpu_size_to_slot(size); | |
211 | } | |
212 | ||
fbf59bc9 TH |
213 | static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) |
214 | { | |
215 | if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) | |
216 | return 0; | |
217 | ||
218 | return pcpu_size_to_slot(chunk->free_size); | |
219 | } | |
220 | ||
88999a89 TH |
221 | /* set the pointer to a chunk in a page struct */ |
222 | static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) | |
223 | { | |
224 | page->index = (unsigned long)pcpu; | |
225 | } | |
226 | ||
227 | /* obtain pointer to a chunk from a page struct */ | |
228 | static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) | |
229 | { | |
230 | return (struct pcpu_chunk *)page->index; | |
231 | } | |
232 | ||
233 | static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) | |
fbf59bc9 | 234 | { |
2f39e637 | 235 | return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; |
fbf59bc9 TH |
236 | } |
237 | ||
9983b6f0 TH |
238 | static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, |
239 | unsigned int cpu, int page_idx) | |
fbf59bc9 | 240 | { |
bba174f5 | 241 | return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] + |
fb435d52 | 242 | (page_idx << PAGE_SHIFT); |
fbf59bc9 TH |
243 | } |
244 | ||
88999a89 TH |
245 | static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk, |
246 | int *rs, int *re, int end) | |
ce3141a2 TH |
247 | { |
248 | *rs = find_next_zero_bit(chunk->populated, end, *rs); | |
249 | *re = find_next_bit(chunk->populated, end, *rs + 1); | |
250 | } | |
251 | ||
88999a89 TH |
252 | static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk, |
253 | int *rs, int *re, int end) | |
ce3141a2 TH |
254 | { |
255 | *rs = find_next_bit(chunk->populated, end, *rs); | |
256 | *re = find_next_zero_bit(chunk->populated, end, *rs + 1); | |
257 | } | |
258 | ||
259 | /* | |
260 | * (Un)populated page region iterators. Iterate over (un)populated | |
b595076a | 261 | * page regions between @start and @end in @chunk. @rs and @re should |
ce3141a2 TH |
262 | * be integer variables and will be set to start and end page index of |
263 | * the current region. | |
264 | */ | |
265 | #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ | |
266 | for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ | |
267 | (rs) < (re); \ | |
268 | (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) | |
269 | ||
270 | #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ | |
271 | for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ | |
272 | (rs) < (re); \ | |
273 | (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) | |
274 | ||
fbf59bc9 | 275 | /** |
1880d93b TH |
276 | * pcpu_mem_alloc - allocate memory |
277 | * @size: bytes to allocate | |
fbf59bc9 | 278 | * |
1880d93b TH |
279 | * Allocate @size bytes. If @size is smaller than PAGE_SIZE, |
280 | * kzalloc() is used; otherwise, vmalloc() is used. The returned | |
281 | * memory is always zeroed. | |
fbf59bc9 | 282 | * |
ccea34b5 TH |
283 | * CONTEXT: |
284 | * Does GFP_KERNEL allocation. | |
285 | * | |
fbf59bc9 | 286 | * RETURNS: |
1880d93b | 287 | * Pointer to the allocated area on success, NULL on failure. |
fbf59bc9 | 288 | */ |
1880d93b | 289 | static void *pcpu_mem_alloc(size_t size) |
fbf59bc9 | 290 | { |
099a19d9 TH |
291 | if (WARN_ON_ONCE(!slab_is_available())) |
292 | return NULL; | |
293 | ||
1880d93b TH |
294 | if (size <= PAGE_SIZE) |
295 | return kzalloc(size, GFP_KERNEL); | |
7af4c093 JJ |
296 | else |
297 | return vzalloc(size); | |
1880d93b | 298 | } |
fbf59bc9 | 299 | |
1880d93b TH |
300 | /** |
301 | * pcpu_mem_free - free memory | |
302 | * @ptr: memory to free | |
303 | * @size: size of the area | |
304 | * | |
305 | * Free @ptr. @ptr should have been allocated using pcpu_mem_alloc(). | |
306 | */ | |
307 | static void pcpu_mem_free(void *ptr, size_t size) | |
308 | { | |
fbf59bc9 | 309 | if (size <= PAGE_SIZE) |
1880d93b | 310 | kfree(ptr); |
fbf59bc9 | 311 | else |
1880d93b | 312 | vfree(ptr); |
fbf59bc9 TH |
313 | } |
314 | ||
315 | /** | |
316 | * pcpu_chunk_relocate - put chunk in the appropriate chunk slot | |
317 | * @chunk: chunk of interest | |
318 | * @oslot: the previous slot it was on | |
319 | * | |
320 | * This function is called after an allocation or free changed @chunk. | |
321 | * New slot according to the changed state is determined and @chunk is | |
edcb4639 TH |
322 | * moved to the slot. Note that the reserved chunk is never put on |
323 | * chunk slots. | |
ccea34b5 TH |
324 | * |
325 | * CONTEXT: | |
326 | * pcpu_lock. | |
fbf59bc9 TH |
327 | */ |
328 | static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) | |
329 | { | |
330 | int nslot = pcpu_chunk_slot(chunk); | |
331 | ||
edcb4639 | 332 | if (chunk != pcpu_reserved_chunk && oslot != nslot) { |
fbf59bc9 TH |
333 | if (oslot < nslot) |
334 | list_move(&chunk->list, &pcpu_slot[nslot]); | |
335 | else | |
336 | list_move_tail(&chunk->list, &pcpu_slot[nslot]); | |
337 | } | |
338 | } | |
339 | ||
9f7dcf22 | 340 | /** |
833af842 TH |
341 | * pcpu_need_to_extend - determine whether chunk area map needs to be extended |
342 | * @chunk: chunk of interest | |
9f7dcf22 | 343 | * |
833af842 TH |
344 | * Determine whether area map of @chunk needs to be extended to |
345 | * accomodate a new allocation. | |
9f7dcf22 | 346 | * |
ccea34b5 | 347 | * CONTEXT: |
833af842 | 348 | * pcpu_lock. |
ccea34b5 | 349 | * |
9f7dcf22 | 350 | * RETURNS: |
833af842 TH |
351 | * New target map allocation length if extension is necessary, 0 |
352 | * otherwise. | |
9f7dcf22 | 353 | */ |
833af842 | 354 | static int pcpu_need_to_extend(struct pcpu_chunk *chunk) |
9f7dcf22 TH |
355 | { |
356 | int new_alloc; | |
9f7dcf22 | 357 | |
9f7dcf22 TH |
358 | if (chunk->map_alloc >= chunk->map_used + 2) |
359 | return 0; | |
360 | ||
361 | new_alloc = PCPU_DFL_MAP_ALLOC; | |
362 | while (new_alloc < chunk->map_used + 2) | |
363 | new_alloc *= 2; | |
364 | ||
833af842 TH |
365 | return new_alloc; |
366 | } | |
367 | ||
368 | /** | |
369 | * pcpu_extend_area_map - extend area map of a chunk | |
370 | * @chunk: chunk of interest | |
371 | * @new_alloc: new target allocation length of the area map | |
372 | * | |
373 | * Extend area map of @chunk to have @new_alloc entries. | |
374 | * | |
375 | * CONTEXT: | |
376 | * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock. | |
377 | * | |
378 | * RETURNS: | |
379 | * 0 on success, -errno on failure. | |
380 | */ | |
381 | static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) | |
382 | { | |
383 | int *old = NULL, *new = NULL; | |
384 | size_t old_size = 0, new_size = new_alloc * sizeof(new[0]); | |
385 | unsigned long flags; | |
386 | ||
387 | new = pcpu_mem_alloc(new_size); | |
388 | if (!new) | |
9f7dcf22 | 389 | return -ENOMEM; |
ccea34b5 | 390 | |
833af842 TH |
391 | /* acquire pcpu_lock and switch to new area map */ |
392 | spin_lock_irqsave(&pcpu_lock, flags); | |
393 | ||
394 | if (new_alloc <= chunk->map_alloc) | |
395 | goto out_unlock; | |
9f7dcf22 | 396 | |
833af842 | 397 | old_size = chunk->map_alloc * sizeof(chunk->map[0]); |
a002d148 HS |
398 | old = chunk->map; |
399 | ||
400 | memcpy(new, old, old_size); | |
9f7dcf22 | 401 | |
9f7dcf22 TH |
402 | chunk->map_alloc = new_alloc; |
403 | chunk->map = new; | |
833af842 TH |
404 | new = NULL; |
405 | ||
406 | out_unlock: | |
407 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
408 | ||
409 | /* | |
410 | * pcpu_mem_free() might end up calling vfree() which uses | |
411 | * IRQ-unsafe lock and thus can't be called under pcpu_lock. | |
412 | */ | |
413 | pcpu_mem_free(old, old_size); | |
414 | pcpu_mem_free(new, new_size); | |
415 | ||
9f7dcf22 TH |
416 | return 0; |
417 | } | |
418 | ||
fbf59bc9 TH |
419 | /** |
420 | * pcpu_split_block - split a map block | |
421 | * @chunk: chunk of interest | |
422 | * @i: index of map block to split | |
cae3aeb8 TH |
423 | * @head: head size in bytes (can be 0) |
424 | * @tail: tail size in bytes (can be 0) | |
fbf59bc9 TH |
425 | * |
426 | * Split the @i'th map block into two or three blocks. If @head is | |
427 | * non-zero, @head bytes block is inserted before block @i moving it | |
428 | * to @i+1 and reducing its size by @head bytes. | |
429 | * | |
430 | * If @tail is non-zero, the target block, which can be @i or @i+1 | |
431 | * depending on @head, is reduced by @tail bytes and @tail byte block | |
432 | * is inserted after the target block. | |
433 | * | |
9f7dcf22 | 434 | * @chunk->map must have enough free slots to accomodate the split. |
ccea34b5 TH |
435 | * |
436 | * CONTEXT: | |
437 | * pcpu_lock. | |
fbf59bc9 | 438 | */ |
9f7dcf22 TH |
439 | static void pcpu_split_block(struct pcpu_chunk *chunk, int i, |
440 | int head, int tail) | |
fbf59bc9 TH |
441 | { |
442 | int nr_extra = !!head + !!tail; | |
1880d93b | 443 | |
9f7dcf22 | 444 | BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra); |
fbf59bc9 | 445 | |
9f7dcf22 | 446 | /* insert new subblocks */ |
fbf59bc9 TH |
447 | memmove(&chunk->map[i + nr_extra], &chunk->map[i], |
448 | sizeof(chunk->map[0]) * (chunk->map_used - i)); | |
449 | chunk->map_used += nr_extra; | |
450 | ||
451 | if (head) { | |
452 | chunk->map[i + 1] = chunk->map[i] - head; | |
453 | chunk->map[i++] = head; | |
454 | } | |
455 | if (tail) { | |
456 | chunk->map[i++] -= tail; | |
457 | chunk->map[i] = tail; | |
458 | } | |
fbf59bc9 TH |
459 | } |
460 | ||
461 | /** | |
462 | * pcpu_alloc_area - allocate area from a pcpu_chunk | |
463 | * @chunk: chunk of interest | |
cae3aeb8 | 464 | * @size: wanted size in bytes |
fbf59bc9 TH |
465 | * @align: wanted align |
466 | * | |
467 | * Try to allocate @size bytes area aligned at @align from @chunk. | |
468 | * Note that this function only allocates the offset. It doesn't | |
469 | * populate or map the area. | |
470 | * | |
9f7dcf22 TH |
471 | * @chunk->map must have at least two free slots. |
472 | * | |
ccea34b5 TH |
473 | * CONTEXT: |
474 | * pcpu_lock. | |
475 | * | |
fbf59bc9 | 476 | * RETURNS: |
9f7dcf22 TH |
477 | * Allocated offset in @chunk on success, -1 if no matching area is |
478 | * found. | |
fbf59bc9 TH |
479 | */ |
480 | static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align) | |
481 | { | |
482 | int oslot = pcpu_chunk_slot(chunk); | |
483 | int max_contig = 0; | |
484 | int i, off; | |
485 | ||
fbf59bc9 TH |
486 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) { |
487 | bool is_last = i + 1 == chunk->map_used; | |
488 | int head, tail; | |
489 | ||
490 | /* extra for alignment requirement */ | |
491 | head = ALIGN(off, align) - off; | |
492 | BUG_ON(i == 0 && head != 0); | |
493 | ||
494 | if (chunk->map[i] < 0) | |
495 | continue; | |
496 | if (chunk->map[i] < head + size) { | |
497 | max_contig = max(chunk->map[i], max_contig); | |
498 | continue; | |
499 | } | |
500 | ||
501 | /* | |
502 | * If head is small or the previous block is free, | |
503 | * merge'em. Note that 'small' is defined as smaller | |
504 | * than sizeof(int), which is very small but isn't too | |
505 | * uncommon for percpu allocations. | |
506 | */ | |
507 | if (head && (head < sizeof(int) || chunk->map[i - 1] > 0)) { | |
508 | if (chunk->map[i - 1] > 0) | |
509 | chunk->map[i - 1] += head; | |
510 | else { | |
511 | chunk->map[i - 1] -= head; | |
512 | chunk->free_size -= head; | |
513 | } | |
514 | chunk->map[i] -= head; | |
515 | off += head; | |
516 | head = 0; | |
517 | } | |
518 | ||
519 | /* if tail is small, just keep it around */ | |
520 | tail = chunk->map[i] - head - size; | |
521 | if (tail < sizeof(int)) | |
522 | tail = 0; | |
523 | ||
524 | /* split if warranted */ | |
525 | if (head || tail) { | |
9f7dcf22 | 526 | pcpu_split_block(chunk, i, head, tail); |
fbf59bc9 TH |
527 | if (head) { |
528 | i++; | |
529 | off += head; | |
530 | max_contig = max(chunk->map[i - 1], max_contig); | |
531 | } | |
532 | if (tail) | |
533 | max_contig = max(chunk->map[i + 1], max_contig); | |
534 | } | |
535 | ||
536 | /* update hint and mark allocated */ | |
537 | if (is_last) | |
538 | chunk->contig_hint = max_contig; /* fully scanned */ | |
539 | else | |
540 | chunk->contig_hint = max(chunk->contig_hint, | |
541 | max_contig); | |
542 | ||
543 | chunk->free_size -= chunk->map[i]; | |
544 | chunk->map[i] = -chunk->map[i]; | |
545 | ||
546 | pcpu_chunk_relocate(chunk, oslot); | |
547 | return off; | |
548 | } | |
549 | ||
550 | chunk->contig_hint = max_contig; /* fully scanned */ | |
551 | pcpu_chunk_relocate(chunk, oslot); | |
552 | ||
9f7dcf22 TH |
553 | /* tell the upper layer that this chunk has no matching area */ |
554 | return -1; | |
fbf59bc9 TH |
555 | } |
556 | ||
557 | /** | |
558 | * pcpu_free_area - free area to a pcpu_chunk | |
559 | * @chunk: chunk of interest | |
560 | * @freeme: offset of area to free | |
561 | * | |
562 | * Free area starting from @freeme to @chunk. Note that this function | |
563 | * only modifies the allocation map. It doesn't depopulate or unmap | |
564 | * the area. | |
ccea34b5 TH |
565 | * |
566 | * CONTEXT: | |
567 | * pcpu_lock. | |
fbf59bc9 TH |
568 | */ |
569 | static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme) | |
570 | { | |
571 | int oslot = pcpu_chunk_slot(chunk); | |
572 | int i, off; | |
573 | ||
574 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) | |
575 | if (off == freeme) | |
576 | break; | |
577 | BUG_ON(off != freeme); | |
578 | BUG_ON(chunk->map[i] > 0); | |
579 | ||
580 | chunk->map[i] = -chunk->map[i]; | |
581 | chunk->free_size += chunk->map[i]; | |
582 | ||
583 | /* merge with previous? */ | |
584 | if (i > 0 && chunk->map[i - 1] >= 0) { | |
585 | chunk->map[i - 1] += chunk->map[i]; | |
586 | chunk->map_used--; | |
587 | memmove(&chunk->map[i], &chunk->map[i + 1], | |
588 | (chunk->map_used - i) * sizeof(chunk->map[0])); | |
589 | i--; | |
590 | } | |
591 | /* merge with next? */ | |
592 | if (i + 1 < chunk->map_used && chunk->map[i + 1] >= 0) { | |
593 | chunk->map[i] += chunk->map[i + 1]; | |
594 | chunk->map_used--; | |
595 | memmove(&chunk->map[i + 1], &chunk->map[i + 2], | |
596 | (chunk->map_used - (i + 1)) * sizeof(chunk->map[0])); | |
597 | } | |
598 | ||
599 | chunk->contig_hint = max(chunk->map[i], chunk->contig_hint); | |
600 | pcpu_chunk_relocate(chunk, oslot); | |
601 | } | |
602 | ||
6081089f TH |
603 | static struct pcpu_chunk *pcpu_alloc_chunk(void) |
604 | { | |
605 | struct pcpu_chunk *chunk; | |
606 | ||
099a19d9 | 607 | chunk = pcpu_mem_alloc(pcpu_chunk_struct_size); |
6081089f TH |
608 | if (!chunk) |
609 | return NULL; | |
610 | ||
611 | chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0])); | |
612 | if (!chunk->map) { | |
613 | kfree(chunk); | |
614 | return NULL; | |
615 | } | |
616 | ||
617 | chunk->map_alloc = PCPU_DFL_MAP_ALLOC; | |
618 | chunk->map[chunk->map_used++] = pcpu_unit_size; | |
619 | ||
620 | INIT_LIST_HEAD(&chunk->list); | |
621 | chunk->free_size = pcpu_unit_size; | |
622 | chunk->contig_hint = pcpu_unit_size; | |
623 | ||
624 | return chunk; | |
625 | } | |
626 | ||
627 | static void pcpu_free_chunk(struct pcpu_chunk *chunk) | |
628 | { | |
629 | if (!chunk) | |
630 | return; | |
631 | pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0])); | |
632 | kfree(chunk); | |
633 | } | |
634 | ||
9f645532 TH |
635 | /* |
636 | * Chunk management implementation. | |
637 | * | |
638 | * To allow different implementations, chunk alloc/free and | |
639 | * [de]population are implemented in a separate file which is pulled | |
640 | * into this file and compiled together. The following functions | |
641 | * should be implemented. | |
642 | * | |
643 | * pcpu_populate_chunk - populate the specified range of a chunk | |
644 | * pcpu_depopulate_chunk - depopulate the specified range of a chunk | |
645 | * pcpu_create_chunk - create a new chunk | |
646 | * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop | |
647 | * pcpu_addr_to_page - translate address to physical address | |
648 | * pcpu_verify_alloc_info - check alloc_info is acceptable during init | |
fbf59bc9 | 649 | */ |
9f645532 TH |
650 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size); |
651 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); | |
652 | static struct pcpu_chunk *pcpu_create_chunk(void); | |
653 | static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); | |
654 | static struct page *pcpu_addr_to_page(void *addr); | |
655 | static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); | |
fbf59bc9 | 656 | |
b0c9778b TH |
657 | #ifdef CONFIG_NEED_PER_CPU_KM |
658 | #include "percpu-km.c" | |
659 | #else | |
9f645532 | 660 | #include "percpu-vm.c" |
b0c9778b | 661 | #endif |
fbf59bc9 | 662 | |
88999a89 TH |
663 | /** |
664 | * pcpu_chunk_addr_search - determine chunk containing specified address | |
665 | * @addr: address for which the chunk needs to be determined. | |
666 | * | |
667 | * RETURNS: | |
668 | * The address of the found chunk. | |
669 | */ | |
670 | static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) | |
671 | { | |
672 | /* is it in the first chunk? */ | |
673 | if (pcpu_addr_in_first_chunk(addr)) { | |
674 | /* is it in the reserved area? */ | |
675 | if (pcpu_addr_in_reserved_chunk(addr)) | |
676 | return pcpu_reserved_chunk; | |
677 | return pcpu_first_chunk; | |
678 | } | |
679 | ||
680 | /* | |
681 | * The address is relative to unit0 which might be unused and | |
682 | * thus unmapped. Offset the address to the unit space of the | |
683 | * current processor before looking it up in the vmalloc | |
684 | * space. Note that any possible cpu id can be used here, so | |
685 | * there's no need to worry about preemption or cpu hotplug. | |
686 | */ | |
687 | addr += pcpu_unit_offsets[raw_smp_processor_id()]; | |
9f645532 | 688 | return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); |
88999a89 TH |
689 | } |
690 | ||
fbf59bc9 | 691 | /** |
edcb4639 | 692 | * pcpu_alloc - the percpu allocator |
cae3aeb8 | 693 | * @size: size of area to allocate in bytes |
fbf59bc9 | 694 | * @align: alignment of area (max PAGE_SIZE) |
edcb4639 | 695 | * @reserved: allocate from the reserved chunk if available |
fbf59bc9 | 696 | * |
ccea34b5 TH |
697 | * Allocate percpu area of @size bytes aligned at @align. |
698 | * | |
699 | * CONTEXT: | |
700 | * Does GFP_KERNEL allocation. | |
fbf59bc9 TH |
701 | * |
702 | * RETURNS: | |
703 | * Percpu pointer to the allocated area on success, NULL on failure. | |
704 | */ | |
43cf38eb | 705 | static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) |
fbf59bc9 | 706 | { |
f2badb0c | 707 | static int warn_limit = 10; |
fbf59bc9 | 708 | struct pcpu_chunk *chunk; |
f2badb0c | 709 | const char *err; |
833af842 | 710 | int slot, off, new_alloc; |
403a91b1 | 711 | unsigned long flags; |
fbf59bc9 | 712 | |
8d408b4b | 713 | if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { |
fbf59bc9 TH |
714 | WARN(true, "illegal size (%zu) or align (%zu) for " |
715 | "percpu allocation\n", size, align); | |
716 | return NULL; | |
717 | } | |
718 | ||
ccea34b5 | 719 | mutex_lock(&pcpu_alloc_mutex); |
403a91b1 | 720 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 721 | |
edcb4639 TH |
722 | /* serve reserved allocations from the reserved chunk if available */ |
723 | if (reserved && pcpu_reserved_chunk) { | |
724 | chunk = pcpu_reserved_chunk; | |
833af842 TH |
725 | |
726 | if (size > chunk->contig_hint) { | |
727 | err = "alloc from reserved chunk failed"; | |
ccea34b5 | 728 | goto fail_unlock; |
f2badb0c | 729 | } |
833af842 TH |
730 | |
731 | while ((new_alloc = pcpu_need_to_extend(chunk))) { | |
732 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
733 | if (pcpu_extend_area_map(chunk, new_alloc) < 0) { | |
734 | err = "failed to extend area map of reserved chunk"; | |
735 | goto fail_unlock_mutex; | |
736 | } | |
737 | spin_lock_irqsave(&pcpu_lock, flags); | |
738 | } | |
739 | ||
edcb4639 TH |
740 | off = pcpu_alloc_area(chunk, size, align); |
741 | if (off >= 0) | |
742 | goto area_found; | |
833af842 | 743 | |
f2badb0c | 744 | err = "alloc from reserved chunk failed"; |
ccea34b5 | 745 | goto fail_unlock; |
edcb4639 TH |
746 | } |
747 | ||
ccea34b5 | 748 | restart: |
edcb4639 | 749 | /* search through normal chunks */ |
fbf59bc9 TH |
750 | for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { |
751 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { | |
752 | if (size > chunk->contig_hint) | |
753 | continue; | |
ccea34b5 | 754 | |
833af842 TH |
755 | new_alloc = pcpu_need_to_extend(chunk); |
756 | if (new_alloc) { | |
757 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
758 | if (pcpu_extend_area_map(chunk, | |
759 | new_alloc) < 0) { | |
760 | err = "failed to extend area map"; | |
761 | goto fail_unlock_mutex; | |
762 | } | |
763 | spin_lock_irqsave(&pcpu_lock, flags); | |
764 | /* | |
765 | * pcpu_lock has been dropped, need to | |
766 | * restart cpu_slot list walking. | |
767 | */ | |
768 | goto restart; | |
ccea34b5 TH |
769 | } |
770 | ||
fbf59bc9 TH |
771 | off = pcpu_alloc_area(chunk, size, align); |
772 | if (off >= 0) | |
773 | goto area_found; | |
fbf59bc9 TH |
774 | } |
775 | } | |
776 | ||
777 | /* hmmm... no space left, create a new chunk */ | |
403a91b1 | 778 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 | 779 | |
6081089f | 780 | chunk = pcpu_create_chunk(); |
f2badb0c TH |
781 | if (!chunk) { |
782 | err = "failed to allocate new chunk"; | |
ccea34b5 | 783 | goto fail_unlock_mutex; |
f2badb0c | 784 | } |
ccea34b5 | 785 | |
403a91b1 | 786 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 787 | pcpu_chunk_relocate(chunk, -1); |
ccea34b5 | 788 | goto restart; |
fbf59bc9 TH |
789 | |
790 | area_found: | |
403a91b1 | 791 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 | 792 | |
fbf59bc9 TH |
793 | /* populate, map and clear the area */ |
794 | if (pcpu_populate_chunk(chunk, off, size)) { | |
403a91b1 | 795 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 796 | pcpu_free_area(chunk, off); |
f2badb0c | 797 | err = "failed to populate"; |
ccea34b5 | 798 | goto fail_unlock; |
fbf59bc9 TH |
799 | } |
800 | ||
ccea34b5 TH |
801 | mutex_unlock(&pcpu_alloc_mutex); |
802 | ||
bba174f5 TH |
803 | /* return address relative to base address */ |
804 | return __addr_to_pcpu_ptr(chunk->base_addr + off); | |
ccea34b5 TH |
805 | |
806 | fail_unlock: | |
403a91b1 | 807 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 TH |
808 | fail_unlock_mutex: |
809 | mutex_unlock(&pcpu_alloc_mutex); | |
f2badb0c TH |
810 | if (warn_limit) { |
811 | pr_warning("PERCPU: allocation failed, size=%zu align=%zu, " | |
812 | "%s\n", size, align, err); | |
813 | dump_stack(); | |
814 | if (!--warn_limit) | |
815 | pr_info("PERCPU: limit reached, disable warning\n"); | |
816 | } | |
ccea34b5 | 817 | return NULL; |
fbf59bc9 | 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 | * | |
9329ba97 TH |
825 | * Allocate zero-filled percpu area of @size bytes aligned at @align. |
826 | * Might sleep. Might trigger writeouts. | |
edcb4639 | 827 | * |
ccea34b5 TH |
828 | * CONTEXT: |
829 | * Does GFP_KERNEL allocation. | |
830 | * | |
edcb4639 TH |
831 | * RETURNS: |
832 | * Percpu pointer to the allocated area on success, NULL on failure. | |
833 | */ | |
43cf38eb | 834 | void __percpu *__alloc_percpu(size_t size, size_t align) |
edcb4639 TH |
835 | { |
836 | return pcpu_alloc(size, align, false); | |
837 | } | |
fbf59bc9 TH |
838 | EXPORT_SYMBOL_GPL(__alloc_percpu); |
839 | ||
edcb4639 TH |
840 | /** |
841 | * __alloc_reserved_percpu - allocate reserved percpu area | |
842 | * @size: size of area to allocate in bytes | |
843 | * @align: alignment of area (max PAGE_SIZE) | |
844 | * | |
9329ba97 TH |
845 | * Allocate zero-filled percpu area of @size bytes aligned at @align |
846 | * from reserved percpu area if arch has set it up; otherwise, | |
847 | * allocation is served from the same dynamic area. Might sleep. | |
848 | * Might trigger writeouts. | |
edcb4639 | 849 | * |
ccea34b5 TH |
850 | * CONTEXT: |
851 | * Does GFP_KERNEL allocation. | |
852 | * | |
edcb4639 TH |
853 | * RETURNS: |
854 | * Percpu pointer to the allocated area on success, NULL on failure. | |
855 | */ | |
43cf38eb | 856 | void __percpu *__alloc_reserved_percpu(size_t size, size_t align) |
edcb4639 TH |
857 | { |
858 | return pcpu_alloc(size, align, true); | |
859 | } | |
860 | ||
a56dbddf TH |
861 | /** |
862 | * pcpu_reclaim - reclaim fully free chunks, workqueue function | |
863 | * @work: unused | |
864 | * | |
865 | * Reclaim all fully free chunks except for the first one. | |
ccea34b5 TH |
866 | * |
867 | * CONTEXT: | |
868 | * workqueue context. | |
a56dbddf TH |
869 | */ |
870 | static void pcpu_reclaim(struct work_struct *work) | |
fbf59bc9 | 871 | { |
a56dbddf TH |
872 | LIST_HEAD(todo); |
873 | struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; | |
874 | struct pcpu_chunk *chunk, *next; | |
875 | ||
ccea34b5 TH |
876 | mutex_lock(&pcpu_alloc_mutex); |
877 | spin_lock_irq(&pcpu_lock); | |
a56dbddf TH |
878 | |
879 | list_for_each_entry_safe(chunk, next, head, list) { | |
880 | WARN_ON(chunk->immutable); | |
881 | ||
882 | /* spare the first one */ | |
883 | if (chunk == list_first_entry(head, struct pcpu_chunk, list)) | |
884 | continue; | |
885 | ||
a56dbddf TH |
886 | list_move(&chunk->list, &todo); |
887 | } | |
888 | ||
ccea34b5 | 889 | spin_unlock_irq(&pcpu_lock); |
a56dbddf TH |
890 | |
891 | list_for_each_entry_safe(chunk, next, &todo, list) { | |
ce3141a2 | 892 | pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); |
6081089f | 893 | pcpu_destroy_chunk(chunk); |
a56dbddf | 894 | } |
971f3918 TH |
895 | |
896 | mutex_unlock(&pcpu_alloc_mutex); | |
fbf59bc9 TH |
897 | } |
898 | ||
899 | /** | |
900 | * free_percpu - free percpu area | |
901 | * @ptr: pointer to area to free | |
902 | * | |
ccea34b5 TH |
903 | * Free percpu area @ptr. |
904 | * | |
905 | * CONTEXT: | |
906 | * Can be called from atomic context. | |
fbf59bc9 | 907 | */ |
43cf38eb | 908 | void free_percpu(void __percpu *ptr) |
fbf59bc9 | 909 | { |
129182e5 | 910 | void *addr; |
fbf59bc9 | 911 | struct pcpu_chunk *chunk; |
ccea34b5 | 912 | unsigned long flags; |
fbf59bc9 TH |
913 | int off; |
914 | ||
915 | if (!ptr) | |
916 | return; | |
917 | ||
129182e5 AM |
918 | addr = __pcpu_ptr_to_addr(ptr); |
919 | ||
ccea34b5 | 920 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 TH |
921 | |
922 | chunk = pcpu_chunk_addr_search(addr); | |
bba174f5 | 923 | off = addr - chunk->base_addr; |
fbf59bc9 TH |
924 | |
925 | pcpu_free_area(chunk, off); | |
926 | ||
a56dbddf | 927 | /* if there are more than one fully free chunks, wake up grim reaper */ |
fbf59bc9 TH |
928 | if (chunk->free_size == pcpu_unit_size) { |
929 | struct pcpu_chunk *pos; | |
930 | ||
a56dbddf | 931 | list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) |
fbf59bc9 | 932 | if (pos != chunk) { |
a56dbddf | 933 | schedule_work(&pcpu_reclaim_work); |
fbf59bc9 TH |
934 | break; |
935 | } | |
936 | } | |
937 | ||
ccea34b5 | 938 | spin_unlock_irqrestore(&pcpu_lock, flags); |
fbf59bc9 TH |
939 | } |
940 | EXPORT_SYMBOL_GPL(free_percpu); | |
941 | ||
10fad5e4 TH |
942 | /** |
943 | * is_kernel_percpu_address - test whether address is from static percpu area | |
944 | * @addr: address to test | |
945 | * | |
946 | * Test whether @addr belongs to in-kernel static percpu area. Module | |
947 | * static percpu areas are not considered. For those, use | |
948 | * is_module_percpu_address(). | |
949 | * | |
950 | * RETURNS: | |
951 | * %true if @addr is from in-kernel static percpu area, %false otherwise. | |
952 | */ | |
953 | bool is_kernel_percpu_address(unsigned long addr) | |
954 | { | |
bbddff05 | 955 | #ifdef CONFIG_SMP |
10fad5e4 TH |
956 | const size_t static_size = __per_cpu_end - __per_cpu_start; |
957 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); | |
958 | unsigned int cpu; | |
959 | ||
960 | for_each_possible_cpu(cpu) { | |
961 | void *start = per_cpu_ptr(base, cpu); | |
962 | ||
963 | if ((void *)addr >= start && (void *)addr < start + static_size) | |
964 | return true; | |
965 | } | |
bbddff05 TH |
966 | #endif |
967 | /* on UP, can't distinguish from other static vars, always false */ | |
10fad5e4 TH |
968 | return false; |
969 | } | |
970 | ||
3b034b0d VG |
971 | /** |
972 | * per_cpu_ptr_to_phys - convert translated percpu address to physical address | |
973 | * @addr: the address to be converted to physical address | |
974 | * | |
975 | * Given @addr which is dereferenceable address obtained via one of | |
976 | * percpu access macros, this function translates it into its physical | |
977 | * address. The caller is responsible for ensuring @addr stays valid | |
978 | * until this function finishes. | |
979 | * | |
980 | * RETURNS: | |
981 | * The physical address for @addr. | |
982 | */ | |
983 | phys_addr_t per_cpu_ptr_to_phys(void *addr) | |
984 | { | |
9983b6f0 TH |
985 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); |
986 | bool in_first_chunk = false; | |
987 | unsigned long first_start, first_end; | |
988 | unsigned int cpu; | |
989 | ||
990 | /* | |
991 | * The following test on first_start/end isn't strictly | |
992 | * necessary but will speed up lookups of addresses which | |
993 | * aren't in the first chunk. | |
994 | */ | |
995 | first_start = pcpu_chunk_addr(pcpu_first_chunk, pcpu_first_unit_cpu, 0); | |
996 | first_end = pcpu_chunk_addr(pcpu_first_chunk, pcpu_last_unit_cpu, | |
997 | pcpu_unit_pages); | |
998 | if ((unsigned long)addr >= first_start && | |
999 | (unsigned long)addr < first_end) { | |
1000 | for_each_possible_cpu(cpu) { | |
1001 | void *start = per_cpu_ptr(base, cpu); | |
1002 | ||
1003 | if (addr >= start && addr < start + pcpu_unit_size) { | |
1004 | in_first_chunk = true; | |
1005 | break; | |
1006 | } | |
1007 | } | |
1008 | } | |
1009 | ||
1010 | if (in_first_chunk) { | |
020ec653 TH |
1011 | if ((unsigned long)addr < VMALLOC_START || |
1012 | (unsigned long)addr >= VMALLOC_END) | |
1013 | return __pa(addr); | |
1014 | else | |
1015 | return page_to_phys(vmalloc_to_page(addr)); | |
1016 | } else | |
9f645532 | 1017 | return page_to_phys(pcpu_addr_to_page(addr)); |
3b034b0d VG |
1018 | } |
1019 | ||
fbf59bc9 | 1020 | /** |
fd1e8a1f TH |
1021 | * pcpu_alloc_alloc_info - allocate percpu allocation info |
1022 | * @nr_groups: the number of groups | |
1023 | * @nr_units: the number of units | |
1024 | * | |
1025 | * Allocate ai which is large enough for @nr_groups groups containing | |
1026 | * @nr_units units. The returned ai's groups[0].cpu_map points to the | |
1027 | * cpu_map array which is long enough for @nr_units and filled with | |
1028 | * NR_CPUS. It's the caller's responsibility to initialize cpu_map | |
1029 | * pointer of other groups. | |
1030 | * | |
1031 | * RETURNS: | |
1032 | * Pointer to the allocated pcpu_alloc_info on success, NULL on | |
1033 | * failure. | |
1034 | */ | |
1035 | struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, | |
1036 | int nr_units) | |
1037 | { | |
1038 | struct pcpu_alloc_info *ai; | |
1039 | size_t base_size, ai_size; | |
1040 | void *ptr; | |
1041 | int unit; | |
1042 | ||
1043 | base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), | |
1044 | __alignof__(ai->groups[0].cpu_map[0])); | |
1045 | ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); | |
1046 | ||
1047 | ptr = alloc_bootmem_nopanic(PFN_ALIGN(ai_size)); | |
1048 | if (!ptr) | |
1049 | return NULL; | |
1050 | ai = ptr; | |
1051 | ptr += base_size; | |
1052 | ||
1053 | ai->groups[0].cpu_map = ptr; | |
1054 | ||
1055 | for (unit = 0; unit < nr_units; unit++) | |
1056 | ai->groups[0].cpu_map[unit] = NR_CPUS; | |
1057 | ||
1058 | ai->nr_groups = nr_groups; | |
1059 | ai->__ai_size = PFN_ALIGN(ai_size); | |
1060 | ||
1061 | return ai; | |
1062 | } | |
1063 | ||
1064 | /** | |
1065 | * pcpu_free_alloc_info - free percpu allocation info | |
1066 | * @ai: pcpu_alloc_info to free | |
1067 | * | |
1068 | * Free @ai which was allocated by pcpu_alloc_alloc_info(). | |
1069 | */ | |
1070 | void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) | |
1071 | { | |
1072 | free_bootmem(__pa(ai), ai->__ai_size); | |
1073 | } | |
1074 | ||
fd1e8a1f TH |
1075 | /** |
1076 | * pcpu_dump_alloc_info - print out information about pcpu_alloc_info | |
1077 | * @lvl: loglevel | |
1078 | * @ai: allocation info to dump | |
1079 | * | |
1080 | * Print out information about @ai using loglevel @lvl. | |
1081 | */ | |
1082 | static void pcpu_dump_alloc_info(const char *lvl, | |
1083 | const struct pcpu_alloc_info *ai) | |
033e48fb | 1084 | { |
fd1e8a1f | 1085 | int group_width = 1, cpu_width = 1, width; |
033e48fb | 1086 | char empty_str[] = "--------"; |
fd1e8a1f TH |
1087 | int alloc = 0, alloc_end = 0; |
1088 | int group, v; | |
1089 | int upa, apl; /* units per alloc, allocs per line */ | |
1090 | ||
1091 | v = ai->nr_groups; | |
1092 | while (v /= 10) | |
1093 | group_width++; | |
033e48fb | 1094 | |
fd1e8a1f | 1095 | v = num_possible_cpus(); |
033e48fb | 1096 | while (v /= 10) |
fd1e8a1f TH |
1097 | cpu_width++; |
1098 | empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; | |
033e48fb | 1099 | |
fd1e8a1f TH |
1100 | upa = ai->alloc_size / ai->unit_size; |
1101 | width = upa * (cpu_width + 1) + group_width + 3; | |
1102 | apl = rounddown_pow_of_two(max(60 / width, 1)); | |
033e48fb | 1103 | |
fd1e8a1f TH |
1104 | printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", |
1105 | lvl, ai->static_size, ai->reserved_size, ai->dyn_size, | |
1106 | ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); | |
033e48fb | 1107 | |
fd1e8a1f TH |
1108 | for (group = 0; group < ai->nr_groups; group++) { |
1109 | const struct pcpu_group_info *gi = &ai->groups[group]; | |
1110 | int unit = 0, unit_end = 0; | |
1111 | ||
1112 | BUG_ON(gi->nr_units % upa); | |
1113 | for (alloc_end += gi->nr_units / upa; | |
1114 | alloc < alloc_end; alloc++) { | |
1115 | if (!(alloc % apl)) { | |
033e48fb | 1116 | printk("\n"); |
fd1e8a1f TH |
1117 | printk("%spcpu-alloc: ", lvl); |
1118 | } | |
1119 | printk("[%0*d] ", group_width, group); | |
1120 | ||
1121 | for (unit_end += upa; unit < unit_end; unit++) | |
1122 | if (gi->cpu_map[unit] != NR_CPUS) | |
1123 | printk("%0*d ", cpu_width, | |
1124 | gi->cpu_map[unit]); | |
1125 | else | |
1126 | printk("%s ", empty_str); | |
033e48fb | 1127 | } |
033e48fb TH |
1128 | } |
1129 | printk("\n"); | |
1130 | } | |
033e48fb | 1131 | |
fbf59bc9 | 1132 | /** |
8d408b4b | 1133 | * pcpu_setup_first_chunk - initialize the first percpu chunk |
fd1e8a1f | 1134 | * @ai: pcpu_alloc_info describing how to percpu area is shaped |
38a6be52 | 1135 | * @base_addr: mapped address |
8d408b4b TH |
1136 | * |
1137 | * Initialize the first percpu chunk which contains the kernel static | |
1138 | * perpcu area. This function is to be called from arch percpu area | |
38a6be52 | 1139 | * setup path. |
8d408b4b | 1140 | * |
fd1e8a1f TH |
1141 | * @ai contains all information necessary to initialize the first |
1142 | * chunk and prime the dynamic percpu allocator. | |
1143 | * | |
1144 | * @ai->static_size is the size of static percpu area. | |
1145 | * | |
1146 | * @ai->reserved_size, if non-zero, specifies the amount of bytes to | |
edcb4639 TH |
1147 | * reserve after the static area in the first chunk. This reserves |
1148 | * the first chunk such that it's available only through reserved | |
1149 | * percpu allocation. This is primarily used to serve module percpu | |
1150 | * static areas on architectures where the addressing model has | |
1151 | * limited offset range for symbol relocations to guarantee module | |
1152 | * percpu symbols fall inside the relocatable range. | |
1153 | * | |
fd1e8a1f TH |
1154 | * @ai->dyn_size determines the number of bytes available for dynamic |
1155 | * allocation in the first chunk. The area between @ai->static_size + | |
1156 | * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. | |
6074d5b0 | 1157 | * |
fd1e8a1f TH |
1158 | * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE |
1159 | * and equal to or larger than @ai->static_size + @ai->reserved_size + | |
1160 | * @ai->dyn_size. | |
8d408b4b | 1161 | * |
fd1e8a1f TH |
1162 | * @ai->atom_size is the allocation atom size and used as alignment |
1163 | * for vm areas. | |
8d408b4b | 1164 | * |
fd1e8a1f TH |
1165 | * @ai->alloc_size is the allocation size and always multiple of |
1166 | * @ai->atom_size. This is larger than @ai->atom_size if | |
1167 | * @ai->unit_size is larger than @ai->atom_size. | |
1168 | * | |
1169 | * @ai->nr_groups and @ai->groups describe virtual memory layout of | |
1170 | * percpu areas. Units which should be colocated are put into the | |
1171 | * same group. Dynamic VM areas will be allocated according to these | |
1172 | * groupings. If @ai->nr_groups is zero, a single group containing | |
1173 | * all units is assumed. | |
8d408b4b | 1174 | * |
38a6be52 TH |
1175 | * The caller should have mapped the first chunk at @base_addr and |
1176 | * copied static data to each unit. | |
fbf59bc9 | 1177 | * |
edcb4639 TH |
1178 | * If the first chunk ends up with both reserved and dynamic areas, it |
1179 | * is served by two chunks - one to serve the core static and reserved | |
1180 | * areas and the other for the dynamic area. They share the same vm | |
1181 | * and page map but uses different area allocation map to stay away | |
1182 | * from each other. The latter chunk is circulated in the chunk slots | |
1183 | * and available for dynamic allocation like any other chunks. | |
1184 | * | |
fbf59bc9 | 1185 | * RETURNS: |
fb435d52 | 1186 | * 0 on success, -errno on failure. |
fbf59bc9 | 1187 | */ |
fb435d52 TH |
1188 | int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, |
1189 | void *base_addr) | |
fbf59bc9 | 1190 | { |
635b75fc | 1191 | static char cpus_buf[4096] __initdata; |
099a19d9 TH |
1192 | static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; |
1193 | static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; | |
fd1e8a1f TH |
1194 | size_t dyn_size = ai->dyn_size; |
1195 | size_t size_sum = ai->static_size + ai->reserved_size + dyn_size; | |
edcb4639 | 1196 | struct pcpu_chunk *schunk, *dchunk = NULL; |
6563297c TH |
1197 | unsigned long *group_offsets; |
1198 | size_t *group_sizes; | |
fb435d52 | 1199 | unsigned long *unit_off; |
fbf59bc9 | 1200 | unsigned int cpu; |
fd1e8a1f TH |
1201 | int *unit_map; |
1202 | int group, unit, i; | |
fbf59bc9 | 1203 | |
635b75fc TH |
1204 | cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask); |
1205 | ||
1206 | #define PCPU_SETUP_BUG_ON(cond) do { \ | |
1207 | if (unlikely(cond)) { \ | |
1208 | pr_emerg("PERCPU: failed to initialize, %s", #cond); \ | |
1209 | pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \ | |
1210 | pcpu_dump_alloc_info(KERN_EMERG, ai); \ | |
1211 | BUG(); \ | |
1212 | } \ | |
1213 | } while (0) | |
1214 | ||
2f39e637 | 1215 | /* sanity checks */ |
635b75fc | 1216 | PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); |
bbddff05 | 1217 | #ifdef CONFIG_SMP |
635b75fc | 1218 | PCPU_SETUP_BUG_ON(!ai->static_size); |
bbddff05 | 1219 | #endif |
635b75fc TH |
1220 | PCPU_SETUP_BUG_ON(!base_addr); |
1221 | PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); | |
1222 | PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK); | |
1223 | PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); | |
099a19d9 | 1224 | PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE); |
9f645532 | 1225 | PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); |
8d408b4b | 1226 | |
6563297c TH |
1227 | /* process group information and build config tables accordingly */ |
1228 | group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0])); | |
1229 | group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0])); | |
fd1e8a1f | 1230 | unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0])); |
fb435d52 | 1231 | unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0])); |
2f39e637 | 1232 | |
fd1e8a1f | 1233 | for (cpu = 0; cpu < nr_cpu_ids; cpu++) |
ffe0d5a5 | 1234 | unit_map[cpu] = UINT_MAX; |
fd1e8a1f | 1235 | pcpu_first_unit_cpu = NR_CPUS; |
2f39e637 | 1236 | |
fd1e8a1f TH |
1237 | for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { |
1238 | const struct pcpu_group_info *gi = &ai->groups[group]; | |
2f39e637 | 1239 | |
6563297c TH |
1240 | group_offsets[group] = gi->base_offset; |
1241 | group_sizes[group] = gi->nr_units * ai->unit_size; | |
1242 | ||
fd1e8a1f TH |
1243 | for (i = 0; i < gi->nr_units; i++) { |
1244 | cpu = gi->cpu_map[i]; | |
1245 | if (cpu == NR_CPUS) | |
1246 | continue; | |
8d408b4b | 1247 | |
635b75fc TH |
1248 | PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids); |
1249 | PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); | |
1250 | PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); | |
fbf59bc9 | 1251 | |
fd1e8a1f | 1252 | unit_map[cpu] = unit + i; |
fb435d52 TH |
1253 | unit_off[cpu] = gi->base_offset + i * ai->unit_size; |
1254 | ||
fd1e8a1f TH |
1255 | if (pcpu_first_unit_cpu == NR_CPUS) |
1256 | pcpu_first_unit_cpu = cpu; | |
46b30ea9 | 1257 | pcpu_last_unit_cpu = cpu; |
fd1e8a1f | 1258 | } |
2f39e637 | 1259 | } |
fd1e8a1f TH |
1260 | pcpu_nr_units = unit; |
1261 | ||
1262 | for_each_possible_cpu(cpu) | |
635b75fc TH |
1263 | PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); |
1264 | ||
1265 | /* we're done parsing the input, undefine BUG macro and dump config */ | |
1266 | #undef PCPU_SETUP_BUG_ON | |
bcbea798 | 1267 | pcpu_dump_alloc_info(KERN_DEBUG, ai); |
fd1e8a1f | 1268 | |
6563297c TH |
1269 | pcpu_nr_groups = ai->nr_groups; |
1270 | pcpu_group_offsets = group_offsets; | |
1271 | pcpu_group_sizes = group_sizes; | |
fd1e8a1f | 1272 | pcpu_unit_map = unit_map; |
fb435d52 | 1273 | pcpu_unit_offsets = unit_off; |
2f39e637 TH |
1274 | |
1275 | /* determine basic parameters */ | |
fd1e8a1f | 1276 | pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; |
d9b55eeb | 1277 | pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; |
6563297c | 1278 | pcpu_atom_size = ai->atom_size; |
ce3141a2 TH |
1279 | pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + |
1280 | BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); | |
cafe8816 | 1281 | |
d9b55eeb TH |
1282 | /* |
1283 | * Allocate chunk slots. The additional last slot is for | |
1284 | * empty chunks. | |
1285 | */ | |
1286 | pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; | |
fbf59bc9 TH |
1287 | pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0])); |
1288 | for (i = 0; i < pcpu_nr_slots; i++) | |
1289 | INIT_LIST_HEAD(&pcpu_slot[i]); | |
1290 | ||
edcb4639 TH |
1291 | /* |
1292 | * Initialize static chunk. If reserved_size is zero, the | |
1293 | * static chunk covers static area + dynamic allocation area | |
1294 | * in the first chunk. If reserved_size is not zero, it | |
1295 | * covers static area + reserved area (mostly used for module | |
1296 | * static percpu allocation). | |
1297 | */ | |
2441d15c TH |
1298 | schunk = alloc_bootmem(pcpu_chunk_struct_size); |
1299 | INIT_LIST_HEAD(&schunk->list); | |
bba174f5 | 1300 | schunk->base_addr = base_addr; |
61ace7fa TH |
1301 | schunk->map = smap; |
1302 | schunk->map_alloc = ARRAY_SIZE(smap); | |
38a6be52 | 1303 | schunk->immutable = true; |
ce3141a2 | 1304 | bitmap_fill(schunk->populated, pcpu_unit_pages); |
edcb4639 | 1305 | |
fd1e8a1f TH |
1306 | if (ai->reserved_size) { |
1307 | schunk->free_size = ai->reserved_size; | |
ae9e6bc9 | 1308 | pcpu_reserved_chunk = schunk; |
fd1e8a1f | 1309 | pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size; |
edcb4639 TH |
1310 | } else { |
1311 | schunk->free_size = dyn_size; | |
1312 | dyn_size = 0; /* dynamic area covered */ | |
1313 | } | |
2441d15c | 1314 | schunk->contig_hint = schunk->free_size; |
fbf59bc9 | 1315 | |
fd1e8a1f | 1316 | schunk->map[schunk->map_used++] = -ai->static_size; |
61ace7fa TH |
1317 | if (schunk->free_size) |
1318 | schunk->map[schunk->map_used++] = schunk->free_size; | |
1319 | ||
edcb4639 TH |
1320 | /* init dynamic chunk if necessary */ |
1321 | if (dyn_size) { | |
ce3141a2 | 1322 | dchunk = alloc_bootmem(pcpu_chunk_struct_size); |
edcb4639 | 1323 | INIT_LIST_HEAD(&dchunk->list); |
bba174f5 | 1324 | dchunk->base_addr = base_addr; |
edcb4639 TH |
1325 | dchunk->map = dmap; |
1326 | dchunk->map_alloc = ARRAY_SIZE(dmap); | |
38a6be52 | 1327 | dchunk->immutable = true; |
ce3141a2 | 1328 | bitmap_fill(dchunk->populated, pcpu_unit_pages); |
edcb4639 TH |
1329 | |
1330 | dchunk->contig_hint = dchunk->free_size = dyn_size; | |
1331 | dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit; | |
1332 | dchunk->map[dchunk->map_used++] = dchunk->free_size; | |
1333 | } | |
1334 | ||
2441d15c | 1335 | /* link the first chunk in */ |
ae9e6bc9 TH |
1336 | pcpu_first_chunk = dchunk ?: schunk; |
1337 | pcpu_chunk_relocate(pcpu_first_chunk, -1); | |
fbf59bc9 TH |
1338 | |
1339 | /* we're done */ | |
bba174f5 | 1340 | pcpu_base_addr = base_addr; |
fb435d52 | 1341 | return 0; |
fbf59bc9 | 1342 | } |
66c3a757 | 1343 | |
bbddff05 TH |
1344 | #ifdef CONFIG_SMP |
1345 | ||
f58dc01b TH |
1346 | const char *pcpu_fc_names[PCPU_FC_NR] __initdata = { |
1347 | [PCPU_FC_AUTO] = "auto", | |
1348 | [PCPU_FC_EMBED] = "embed", | |
1349 | [PCPU_FC_PAGE] = "page", | |
f58dc01b | 1350 | }; |
66c3a757 | 1351 | |
f58dc01b | 1352 | enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; |
66c3a757 | 1353 | |
f58dc01b TH |
1354 | static int __init percpu_alloc_setup(char *str) |
1355 | { | |
1356 | if (0) | |
1357 | /* nada */; | |
1358 | #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK | |
1359 | else if (!strcmp(str, "embed")) | |
1360 | pcpu_chosen_fc = PCPU_FC_EMBED; | |
1361 | #endif | |
1362 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK | |
1363 | else if (!strcmp(str, "page")) | |
1364 | pcpu_chosen_fc = PCPU_FC_PAGE; | |
f58dc01b TH |
1365 | #endif |
1366 | else | |
1367 | pr_warning("PERCPU: unknown allocator %s specified\n", str); | |
66c3a757 | 1368 | |
f58dc01b | 1369 | return 0; |
66c3a757 | 1370 | } |
f58dc01b | 1371 | early_param("percpu_alloc", percpu_alloc_setup); |
66c3a757 | 1372 | |
3c9a024f TH |
1373 | /* |
1374 | * pcpu_embed_first_chunk() is used by the generic percpu setup. | |
1375 | * Build it if needed by the arch config or the generic setup is going | |
1376 | * to be used. | |
1377 | */ | |
08fc4580 TH |
1378 | #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ |
1379 | !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) | |
3c9a024f TH |
1380 | #define BUILD_EMBED_FIRST_CHUNK |
1381 | #endif | |
1382 | ||
1383 | /* build pcpu_page_first_chunk() iff needed by the arch config */ | |
1384 | #if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) | |
1385 | #define BUILD_PAGE_FIRST_CHUNK | |
1386 | #endif | |
1387 | ||
1388 | /* pcpu_build_alloc_info() is used by both embed and page first chunk */ | |
1389 | #if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK) | |
1390 | /** | |
1391 | * pcpu_build_alloc_info - build alloc_info considering distances between CPUs | |
1392 | * @reserved_size: the size of reserved percpu area in bytes | |
1393 | * @dyn_size: minimum free size for dynamic allocation in bytes | |
1394 | * @atom_size: allocation atom size | |
1395 | * @cpu_distance_fn: callback to determine distance between cpus, optional | |
1396 | * | |
1397 | * This function determines grouping of units, their mappings to cpus | |
1398 | * and other parameters considering needed percpu size, allocation | |
1399 | * atom size and distances between CPUs. | |
1400 | * | |
1401 | * Groups are always mutliples of atom size and CPUs which are of | |
1402 | * LOCAL_DISTANCE both ways are grouped together and share space for | |
1403 | * units in the same group. The returned configuration is guaranteed | |
1404 | * to have CPUs on different nodes on different groups and >=75% usage | |
1405 | * of allocated virtual address space. | |
1406 | * | |
1407 | * RETURNS: | |
1408 | * On success, pointer to the new allocation_info is returned. On | |
1409 | * failure, ERR_PTR value is returned. | |
1410 | */ | |
1411 | static struct pcpu_alloc_info * __init pcpu_build_alloc_info( | |
1412 | size_t reserved_size, size_t dyn_size, | |
1413 | size_t atom_size, | |
1414 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn) | |
1415 | { | |
1416 | static int group_map[NR_CPUS] __initdata; | |
1417 | static int group_cnt[NR_CPUS] __initdata; | |
1418 | const size_t static_size = __per_cpu_end - __per_cpu_start; | |
1419 | int nr_groups = 1, nr_units = 0; | |
1420 | size_t size_sum, min_unit_size, alloc_size; | |
1421 | int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ | |
1422 | int last_allocs, group, unit; | |
1423 | unsigned int cpu, tcpu; | |
1424 | struct pcpu_alloc_info *ai; | |
1425 | unsigned int *cpu_map; | |
1426 | ||
1427 | /* this function may be called multiple times */ | |
1428 | memset(group_map, 0, sizeof(group_map)); | |
1429 | memset(group_cnt, 0, sizeof(group_cnt)); | |
1430 | ||
1431 | /* calculate size_sum and ensure dyn_size is enough for early alloc */ | |
1432 | size_sum = PFN_ALIGN(static_size + reserved_size + | |
1433 | max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE)); | |
1434 | dyn_size = size_sum - static_size - reserved_size; | |
1435 | ||
1436 | /* | |
1437 | * Determine min_unit_size, alloc_size and max_upa such that | |
1438 | * alloc_size is multiple of atom_size and is the smallest | |
1439 | * which can accomodate 4k aligned segments which are equal to | |
1440 | * or larger than min_unit_size. | |
1441 | */ | |
1442 | min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); | |
1443 | ||
1444 | alloc_size = roundup(min_unit_size, atom_size); | |
1445 | upa = alloc_size / min_unit_size; | |
1446 | while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) | |
1447 | upa--; | |
1448 | max_upa = upa; | |
1449 | ||
1450 | /* group cpus according to their proximity */ | |
1451 | for_each_possible_cpu(cpu) { | |
1452 | group = 0; | |
1453 | next_group: | |
1454 | for_each_possible_cpu(tcpu) { | |
1455 | if (cpu == tcpu) | |
1456 | break; | |
1457 | if (group_map[tcpu] == group && cpu_distance_fn && | |
1458 | (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || | |
1459 | cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { | |
1460 | group++; | |
1461 | nr_groups = max(nr_groups, group + 1); | |
1462 | goto next_group; | |
1463 | } | |
1464 | } | |
1465 | group_map[cpu] = group; | |
1466 | group_cnt[group]++; | |
1467 | } | |
1468 | ||
1469 | /* | |
1470 | * Expand unit size until address space usage goes over 75% | |
1471 | * and then as much as possible without using more address | |
1472 | * space. | |
1473 | */ | |
1474 | last_allocs = INT_MAX; | |
1475 | for (upa = max_upa; upa; upa--) { | |
1476 | int allocs = 0, wasted = 0; | |
1477 | ||
1478 | if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) | |
1479 | continue; | |
1480 | ||
1481 | for (group = 0; group < nr_groups; group++) { | |
1482 | int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); | |
1483 | allocs += this_allocs; | |
1484 | wasted += this_allocs * upa - group_cnt[group]; | |
1485 | } | |
1486 | ||
1487 | /* | |
1488 | * Don't accept if wastage is over 1/3. The | |
1489 | * greater-than comparison ensures upa==1 always | |
1490 | * passes the following check. | |
1491 | */ | |
1492 | if (wasted > num_possible_cpus() / 3) | |
1493 | continue; | |
1494 | ||
1495 | /* and then don't consume more memory */ | |
1496 | if (allocs > last_allocs) | |
1497 | break; | |
1498 | last_allocs = allocs; | |
1499 | best_upa = upa; | |
1500 | } | |
1501 | upa = best_upa; | |
1502 | ||
1503 | /* allocate and fill alloc_info */ | |
1504 | for (group = 0; group < nr_groups; group++) | |
1505 | nr_units += roundup(group_cnt[group], upa); | |
1506 | ||
1507 | ai = pcpu_alloc_alloc_info(nr_groups, nr_units); | |
1508 | if (!ai) | |
1509 | return ERR_PTR(-ENOMEM); | |
1510 | cpu_map = ai->groups[0].cpu_map; | |
1511 | ||
1512 | for (group = 0; group < nr_groups; group++) { | |
1513 | ai->groups[group].cpu_map = cpu_map; | |
1514 | cpu_map += roundup(group_cnt[group], upa); | |
1515 | } | |
1516 | ||
1517 | ai->static_size = static_size; | |
1518 | ai->reserved_size = reserved_size; | |
1519 | ai->dyn_size = dyn_size; | |
1520 | ai->unit_size = alloc_size / upa; | |
1521 | ai->atom_size = atom_size; | |
1522 | ai->alloc_size = alloc_size; | |
1523 | ||
1524 | for (group = 0, unit = 0; group_cnt[group]; group++) { | |
1525 | struct pcpu_group_info *gi = &ai->groups[group]; | |
1526 | ||
1527 | /* | |
1528 | * Initialize base_offset as if all groups are located | |
1529 | * back-to-back. The caller should update this to | |
1530 | * reflect actual allocation. | |
1531 | */ | |
1532 | gi->base_offset = unit * ai->unit_size; | |
1533 | ||
1534 | for_each_possible_cpu(cpu) | |
1535 | if (group_map[cpu] == group) | |
1536 | gi->cpu_map[gi->nr_units++] = cpu; | |
1537 | gi->nr_units = roundup(gi->nr_units, upa); | |
1538 | unit += gi->nr_units; | |
1539 | } | |
1540 | BUG_ON(unit != nr_units); | |
1541 | ||
1542 | return ai; | |
1543 | } | |
1544 | #endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */ | |
1545 | ||
1546 | #if defined(BUILD_EMBED_FIRST_CHUNK) | |
66c3a757 TH |
1547 | /** |
1548 | * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem | |
66c3a757 | 1549 | * @reserved_size: the size of reserved percpu area in bytes |
4ba6ce25 | 1550 | * @dyn_size: minimum free size for dynamic allocation in bytes |
c8826dd5 TH |
1551 | * @atom_size: allocation atom size |
1552 | * @cpu_distance_fn: callback to determine distance between cpus, optional | |
1553 | * @alloc_fn: function to allocate percpu page | |
1554 | * @free_fn: funtion to free percpu page | |
66c3a757 TH |
1555 | * |
1556 | * This is a helper to ease setting up embedded first percpu chunk and | |
1557 | * can be called where pcpu_setup_first_chunk() is expected. | |
1558 | * | |
1559 | * If this function is used to setup the first chunk, it is allocated | |
c8826dd5 TH |
1560 | * by calling @alloc_fn and used as-is without being mapped into |
1561 | * vmalloc area. Allocations are always whole multiples of @atom_size | |
1562 | * aligned to @atom_size. | |
1563 | * | |
1564 | * This enables the first chunk to piggy back on the linear physical | |
1565 | * mapping which often uses larger page size. Please note that this | |
1566 | * can result in very sparse cpu->unit mapping on NUMA machines thus | |
1567 | * requiring large vmalloc address space. Don't use this allocator if | |
1568 | * vmalloc space is not orders of magnitude larger than distances | |
1569 | * between node memory addresses (ie. 32bit NUMA machines). | |
66c3a757 | 1570 | * |
4ba6ce25 | 1571 | * @dyn_size specifies the minimum dynamic area size. |
66c3a757 TH |
1572 | * |
1573 | * If the needed size is smaller than the minimum or specified unit | |
c8826dd5 | 1574 | * size, the leftover is returned using @free_fn. |
66c3a757 TH |
1575 | * |
1576 | * RETURNS: | |
fb435d52 | 1577 | * 0 on success, -errno on failure. |
66c3a757 | 1578 | */ |
4ba6ce25 | 1579 | int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, |
c8826dd5 TH |
1580 | size_t atom_size, |
1581 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn, | |
1582 | pcpu_fc_alloc_fn_t alloc_fn, | |
1583 | pcpu_fc_free_fn_t free_fn) | |
66c3a757 | 1584 | { |
c8826dd5 TH |
1585 | void *base = (void *)ULONG_MAX; |
1586 | void **areas = NULL; | |
fd1e8a1f | 1587 | struct pcpu_alloc_info *ai; |
6ea529a2 | 1588 | size_t size_sum, areas_size, max_distance; |
c8826dd5 | 1589 | int group, i, rc; |
66c3a757 | 1590 | |
c8826dd5 TH |
1591 | ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, |
1592 | cpu_distance_fn); | |
fd1e8a1f TH |
1593 | if (IS_ERR(ai)) |
1594 | return PTR_ERR(ai); | |
66c3a757 | 1595 | |
fd1e8a1f | 1596 | size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; |
c8826dd5 | 1597 | areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); |
fa8a7094 | 1598 | |
c8826dd5 TH |
1599 | areas = alloc_bootmem_nopanic(areas_size); |
1600 | if (!areas) { | |
fb435d52 | 1601 | rc = -ENOMEM; |
c8826dd5 | 1602 | goto out_free; |
fa8a7094 | 1603 | } |
66c3a757 | 1604 | |
c8826dd5 TH |
1605 | /* allocate, copy and determine base address */ |
1606 | for (group = 0; group < ai->nr_groups; group++) { | |
1607 | struct pcpu_group_info *gi = &ai->groups[group]; | |
1608 | unsigned int cpu = NR_CPUS; | |
1609 | void *ptr; | |
1610 | ||
1611 | for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) | |
1612 | cpu = gi->cpu_map[i]; | |
1613 | BUG_ON(cpu == NR_CPUS); | |
1614 | ||
1615 | /* allocate space for the whole group */ | |
1616 | ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); | |
1617 | if (!ptr) { | |
1618 | rc = -ENOMEM; | |
1619 | goto out_free_areas; | |
1620 | } | |
1621 | areas[group] = ptr; | |
fd1e8a1f | 1622 | |
c8826dd5 TH |
1623 | base = min(ptr, base); |
1624 | ||
1625 | for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { | |
1626 | if (gi->cpu_map[i] == NR_CPUS) { | |
1627 | /* unused unit, free whole */ | |
1628 | free_fn(ptr, ai->unit_size); | |
1629 | continue; | |
1630 | } | |
1631 | /* copy and return the unused part */ | |
1632 | memcpy(ptr, __per_cpu_load, ai->static_size); | |
1633 | free_fn(ptr + size_sum, ai->unit_size - size_sum); | |
1634 | } | |
fa8a7094 | 1635 | } |
66c3a757 | 1636 | |
c8826dd5 | 1637 | /* base address is now known, determine group base offsets */ |
6ea529a2 TH |
1638 | max_distance = 0; |
1639 | for (group = 0; group < ai->nr_groups; group++) { | |
c8826dd5 | 1640 | ai->groups[group].base_offset = areas[group] - base; |
1a0c3298 TH |
1641 | max_distance = max_t(size_t, max_distance, |
1642 | ai->groups[group].base_offset); | |
6ea529a2 TH |
1643 | } |
1644 | max_distance += ai->unit_size; | |
1645 | ||
1646 | /* warn if maximum distance is further than 75% of vmalloc space */ | |
1647 | if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) { | |
1a0c3298 | 1648 | pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc " |
6ea529a2 TH |
1649 | "space 0x%lx\n", |
1650 | max_distance, VMALLOC_END - VMALLOC_START); | |
1651 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK | |
1652 | /* and fail if we have fallback */ | |
1653 | rc = -EINVAL; | |
1654 | goto out_free; | |
1655 | #endif | |
1656 | } | |
c8826dd5 | 1657 | |
004018e2 | 1658 | pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", |
fd1e8a1f TH |
1659 | PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, |
1660 | ai->dyn_size, ai->unit_size); | |
d4b95f80 | 1661 | |
fb435d52 | 1662 | rc = pcpu_setup_first_chunk(ai, base); |
c8826dd5 TH |
1663 | goto out_free; |
1664 | ||
1665 | out_free_areas: | |
1666 | for (group = 0; group < ai->nr_groups; group++) | |
1667 | free_fn(areas[group], | |
1668 | ai->groups[group].nr_units * ai->unit_size); | |
1669 | out_free: | |
fd1e8a1f | 1670 | pcpu_free_alloc_info(ai); |
c8826dd5 TH |
1671 | if (areas) |
1672 | free_bootmem(__pa(areas), areas_size); | |
fb435d52 | 1673 | return rc; |
d4b95f80 | 1674 | } |
3c9a024f | 1675 | #endif /* BUILD_EMBED_FIRST_CHUNK */ |
d4b95f80 | 1676 | |
3c9a024f | 1677 | #ifdef BUILD_PAGE_FIRST_CHUNK |
d4b95f80 | 1678 | /** |
00ae4064 | 1679 | * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages |
d4b95f80 TH |
1680 | * @reserved_size: the size of reserved percpu area in bytes |
1681 | * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE | |
1682 | * @free_fn: funtion to free percpu page, always called with PAGE_SIZE | |
1683 | * @populate_pte_fn: function to populate pte | |
1684 | * | |
00ae4064 TH |
1685 | * This is a helper to ease setting up page-remapped first percpu |
1686 | * chunk and can be called where pcpu_setup_first_chunk() is expected. | |
d4b95f80 TH |
1687 | * |
1688 | * This is the basic allocator. Static percpu area is allocated | |
1689 | * page-by-page into vmalloc area. | |
1690 | * | |
1691 | * RETURNS: | |
fb435d52 | 1692 | * 0 on success, -errno on failure. |
d4b95f80 | 1693 | */ |
fb435d52 TH |
1694 | int __init pcpu_page_first_chunk(size_t reserved_size, |
1695 | pcpu_fc_alloc_fn_t alloc_fn, | |
1696 | pcpu_fc_free_fn_t free_fn, | |
1697 | pcpu_fc_populate_pte_fn_t populate_pte_fn) | |
d4b95f80 | 1698 | { |
8f05a6a6 | 1699 | static struct vm_struct vm; |
fd1e8a1f | 1700 | struct pcpu_alloc_info *ai; |
00ae4064 | 1701 | char psize_str[16]; |
ce3141a2 | 1702 | int unit_pages; |
d4b95f80 | 1703 | size_t pages_size; |
ce3141a2 | 1704 | struct page **pages; |
fb435d52 | 1705 | int unit, i, j, rc; |
d4b95f80 | 1706 | |
00ae4064 TH |
1707 | snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); |
1708 | ||
4ba6ce25 | 1709 | ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL); |
fd1e8a1f TH |
1710 | if (IS_ERR(ai)) |
1711 | return PTR_ERR(ai); | |
1712 | BUG_ON(ai->nr_groups != 1); | |
1713 | BUG_ON(ai->groups[0].nr_units != num_possible_cpus()); | |
1714 | ||
1715 | unit_pages = ai->unit_size >> PAGE_SHIFT; | |
d4b95f80 TH |
1716 | |
1717 | /* unaligned allocations can't be freed, round up to page size */ | |
fd1e8a1f TH |
1718 | pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * |
1719 | sizeof(pages[0])); | |
ce3141a2 | 1720 | pages = alloc_bootmem(pages_size); |
d4b95f80 | 1721 | |
8f05a6a6 | 1722 | /* allocate pages */ |
d4b95f80 | 1723 | j = 0; |
fd1e8a1f | 1724 | for (unit = 0; unit < num_possible_cpus(); unit++) |
ce3141a2 | 1725 | for (i = 0; i < unit_pages; i++) { |
fd1e8a1f | 1726 | unsigned int cpu = ai->groups[0].cpu_map[unit]; |
d4b95f80 TH |
1727 | void *ptr; |
1728 | ||
3cbc8565 | 1729 | ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); |
d4b95f80 | 1730 | if (!ptr) { |
00ae4064 TH |
1731 | pr_warning("PERCPU: failed to allocate %s page " |
1732 | "for cpu%u\n", psize_str, cpu); | |
d4b95f80 TH |
1733 | goto enomem; |
1734 | } | |
ce3141a2 | 1735 | pages[j++] = virt_to_page(ptr); |
d4b95f80 TH |
1736 | } |
1737 | ||
8f05a6a6 TH |
1738 | /* allocate vm area, map the pages and copy static data */ |
1739 | vm.flags = VM_ALLOC; | |
fd1e8a1f | 1740 | vm.size = num_possible_cpus() * ai->unit_size; |
8f05a6a6 TH |
1741 | vm_area_register_early(&vm, PAGE_SIZE); |
1742 | ||
fd1e8a1f | 1743 | for (unit = 0; unit < num_possible_cpus(); unit++) { |
1d9d3257 | 1744 | unsigned long unit_addr = |
fd1e8a1f | 1745 | (unsigned long)vm.addr + unit * ai->unit_size; |
8f05a6a6 | 1746 | |
ce3141a2 | 1747 | for (i = 0; i < unit_pages; i++) |
8f05a6a6 TH |
1748 | populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); |
1749 | ||
1750 | /* pte already populated, the following shouldn't fail */ | |
fb435d52 TH |
1751 | rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], |
1752 | unit_pages); | |
1753 | if (rc < 0) | |
1754 | panic("failed to map percpu area, err=%d\n", rc); | |
66c3a757 | 1755 | |
8f05a6a6 TH |
1756 | /* |
1757 | * FIXME: Archs with virtual cache should flush local | |
1758 | * cache for the linear mapping here - something | |
1759 | * equivalent to flush_cache_vmap() on the local cpu. | |
1760 | * flush_cache_vmap() can't be used as most supporting | |
1761 | * data structures are not set up yet. | |
1762 | */ | |
1763 | ||
1764 | /* copy static data */ | |
fd1e8a1f | 1765 | memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); |
66c3a757 TH |
1766 | } |
1767 | ||
1768 | /* we're ready, commit */ | |
1d9d3257 | 1769 | pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n", |
fd1e8a1f TH |
1770 | unit_pages, psize_str, vm.addr, ai->static_size, |
1771 | ai->reserved_size, ai->dyn_size); | |
d4b95f80 | 1772 | |
fb435d52 | 1773 | rc = pcpu_setup_first_chunk(ai, vm.addr); |
d4b95f80 TH |
1774 | goto out_free_ar; |
1775 | ||
1776 | enomem: | |
1777 | while (--j >= 0) | |
ce3141a2 | 1778 | free_fn(page_address(pages[j]), PAGE_SIZE); |
fb435d52 | 1779 | rc = -ENOMEM; |
d4b95f80 | 1780 | out_free_ar: |
ce3141a2 | 1781 | free_bootmem(__pa(pages), pages_size); |
fd1e8a1f | 1782 | pcpu_free_alloc_info(ai); |
fb435d52 | 1783 | return rc; |
d4b95f80 | 1784 | } |
3c9a024f | 1785 | #endif /* BUILD_PAGE_FIRST_CHUNK */ |
d4b95f80 | 1786 | |
bbddff05 | 1787 | #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA |
e74e3962 | 1788 | /* |
bbddff05 | 1789 | * Generic SMP percpu area setup. |
e74e3962 TH |
1790 | * |
1791 | * The embedding helper is used because its behavior closely resembles | |
1792 | * the original non-dynamic generic percpu area setup. This is | |
1793 | * important because many archs have addressing restrictions and might | |
1794 | * fail if the percpu area is located far away from the previous | |
1795 | * location. As an added bonus, in non-NUMA cases, embedding is | |
1796 | * generally a good idea TLB-wise because percpu area can piggy back | |
1797 | * on the physical linear memory mapping which uses large page | |
1798 | * mappings on applicable archs. | |
1799 | */ | |
e74e3962 TH |
1800 | unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; |
1801 | EXPORT_SYMBOL(__per_cpu_offset); | |
1802 | ||
c8826dd5 TH |
1803 | static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, |
1804 | size_t align) | |
1805 | { | |
1806 | return __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS)); | |
1807 | } | |
66c3a757 | 1808 | |
c8826dd5 TH |
1809 | static void __init pcpu_dfl_fc_free(void *ptr, size_t size) |
1810 | { | |
1811 | free_bootmem(__pa(ptr), size); | |
1812 | } | |
1813 | ||
e74e3962 TH |
1814 | void __init setup_per_cpu_areas(void) |
1815 | { | |
e74e3962 TH |
1816 | unsigned long delta; |
1817 | unsigned int cpu; | |
fb435d52 | 1818 | int rc; |
e74e3962 TH |
1819 | |
1820 | /* | |
1821 | * Always reserve area for module percpu variables. That's | |
1822 | * what the legacy allocator did. | |
1823 | */ | |
fb435d52 | 1824 | rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, |
c8826dd5 TH |
1825 | PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, |
1826 | pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); | |
fb435d52 | 1827 | if (rc < 0) |
bbddff05 | 1828 | panic("Failed to initialize percpu areas."); |
e74e3962 TH |
1829 | |
1830 | delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; | |
1831 | for_each_possible_cpu(cpu) | |
fb435d52 | 1832 | __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; |
66c3a757 | 1833 | } |
bbddff05 TH |
1834 | #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ |
1835 | ||
1836 | #else /* CONFIG_SMP */ | |
1837 | ||
1838 | /* | |
1839 | * UP percpu area setup. | |
1840 | * | |
1841 | * UP always uses km-based percpu allocator with identity mapping. | |
1842 | * Static percpu variables are indistinguishable from the usual static | |
1843 | * variables and don't require any special preparation. | |
1844 | */ | |
1845 | void __init setup_per_cpu_areas(void) | |
1846 | { | |
1847 | const size_t unit_size = | |
1848 | roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE, | |
1849 | PERCPU_DYNAMIC_RESERVE)); | |
1850 | struct pcpu_alloc_info *ai; | |
1851 | void *fc; | |
1852 | ||
1853 | ai = pcpu_alloc_alloc_info(1, 1); | |
1854 | fc = __alloc_bootmem(unit_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS)); | |
1855 | if (!ai || !fc) | |
1856 | panic("Failed to allocate memory for percpu areas."); | |
1857 | ||
1858 | ai->dyn_size = unit_size; | |
1859 | ai->unit_size = unit_size; | |
1860 | ai->atom_size = unit_size; | |
1861 | ai->alloc_size = unit_size; | |
1862 | ai->groups[0].nr_units = 1; | |
1863 | ai->groups[0].cpu_map[0] = 0; | |
1864 | ||
1865 | if (pcpu_setup_first_chunk(ai, fc) < 0) | |
1866 | panic("Failed to initialize percpu areas."); | |
1867 | } | |
1868 | ||
1869 | #endif /* CONFIG_SMP */ | |
099a19d9 TH |
1870 | |
1871 | /* | |
1872 | * First and reserved chunks are initialized with temporary allocation | |
1873 | * map in initdata so that they can be used before slab is online. | |
1874 | * This function is called after slab is brought up and replaces those | |
1875 | * with properly allocated maps. | |
1876 | */ | |
1877 | void __init percpu_init_late(void) | |
1878 | { | |
1879 | struct pcpu_chunk *target_chunks[] = | |
1880 | { pcpu_first_chunk, pcpu_reserved_chunk, NULL }; | |
1881 | struct pcpu_chunk *chunk; | |
1882 | unsigned long flags; | |
1883 | int i; | |
1884 | ||
1885 | for (i = 0; (chunk = target_chunks[i]); i++) { | |
1886 | int *map; | |
1887 | const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]); | |
1888 | ||
1889 | BUILD_BUG_ON(size > PAGE_SIZE); | |
1890 | ||
1891 | map = pcpu_mem_alloc(size); | |
1892 | BUG_ON(!map); | |
1893 | ||
1894 | spin_lock_irqsave(&pcpu_lock, flags); | |
1895 | memcpy(map, chunk->map, size); | |
1896 | chunk->map = map; | |
1897 | spin_unlock_irqrestore(&pcpu_lock, flags); | |
1898 | } | |
1899 | } |