Commit | Line | Data |
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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 | * | |
5e81ee3e DZF |
7 | * Copyright (C) 2017 Facebook Inc. |
8 | * Copyright (C) 2017 Dennis Zhou <dennisszhou@gmail.com> | |
9 | * | |
9c015162 | 10 | * This file is released under the GPLv2 license. |
fbf59bc9 | 11 | * |
9c015162 DZF |
12 | * The percpu allocator handles both static and dynamic areas. Percpu |
13 | * areas are allocated in chunks which are divided into units. There is | |
14 | * a 1-to-1 mapping for units to possible cpus. These units are grouped | |
15 | * based on NUMA properties of the machine. | |
fbf59bc9 TH |
16 | * |
17 | * c0 c1 c2 | |
18 | * ------------------- ------------------- ------------ | |
19 | * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u | |
20 | * ------------------- ...... ------------------- .... ------------ | |
21 | * | |
9c015162 DZF |
22 | * Allocation is done by offsets into a unit's address space. Ie., an |
23 | * area of 512 bytes at 6k in c1 occupies 512 bytes at 6k in c1:u0, | |
24 | * c1:u1, c1:u2, etc. On NUMA machines, the mapping may be non-linear | |
25 | * and even sparse. Access is handled by configuring percpu base | |
26 | * registers according to the cpu to unit mappings and offsetting the | |
27 | * base address using pcpu_unit_size. | |
28 | * | |
29 | * There is special consideration for the first chunk which must handle | |
30 | * the static percpu variables in the kernel image as allocation services | |
5e81ee3e | 31 | * are not online yet. In short, the first chunk is structured like so: |
9c015162 DZF |
32 | * |
33 | * <Static | [Reserved] | Dynamic> | |
34 | * | |
35 | * The static data is copied from the original section managed by the | |
36 | * linker. The reserved section, if non-zero, primarily manages static | |
37 | * percpu variables from kernel modules. Finally, the dynamic section | |
38 | * takes care of normal allocations. | |
fbf59bc9 | 39 | * |
5e81ee3e DZF |
40 | * The allocator organizes chunks into lists according to free size and |
41 | * tries to allocate from the fullest chunk first. Each chunk is managed | |
42 | * by a bitmap with metadata blocks. The allocation map is updated on | |
43 | * every allocation and free to reflect the current state while the boundary | |
44 | * map is only updated on allocation. Each metadata block contains | |
45 | * information to help mitigate the need to iterate over large portions | |
46 | * of the bitmap. The reverse mapping from page to chunk is stored in | |
47 | * the page's index. Lastly, units are lazily backed and grow in unison. | |
48 | * | |
49 | * There is a unique conversion that goes on here between bytes and bits. | |
50 | * Each bit represents a fragment of size PCPU_MIN_ALLOC_SIZE. The chunk | |
51 | * tracks the number of pages it is responsible for in nr_pages. Helper | |
52 | * functions are used to convert from between the bytes, bits, and blocks. | |
53 | * All hints are managed in bits unless explicitly stated. | |
9c015162 | 54 | * |
4091fb95 | 55 | * To use this allocator, arch code should do the following: |
fbf59bc9 | 56 | * |
fbf59bc9 | 57 | * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate |
e0100983 TH |
58 | * regular address to percpu pointer and back if they need to be |
59 | * different from the default | |
fbf59bc9 | 60 | * |
8d408b4b TH |
61 | * - use pcpu_setup_first_chunk() during percpu area initialization to |
62 | * setup the first chunk containing the kernel static percpu area | |
fbf59bc9 TH |
63 | */ |
64 | ||
870d4b12 JP |
65 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
66 | ||
fbf59bc9 TH |
67 | #include <linux/bitmap.h> |
68 | #include <linux/bootmem.h> | |
fd1e8a1f | 69 | #include <linux/err.h> |
ca460b3c | 70 | #include <linux/lcm.h> |
fbf59bc9 | 71 | #include <linux/list.h> |
a530b795 | 72 | #include <linux/log2.h> |
fbf59bc9 TH |
73 | #include <linux/mm.h> |
74 | #include <linux/module.h> | |
75 | #include <linux/mutex.h> | |
76 | #include <linux/percpu.h> | |
77 | #include <linux/pfn.h> | |
fbf59bc9 | 78 | #include <linux/slab.h> |
ccea34b5 | 79 | #include <linux/spinlock.h> |
fbf59bc9 | 80 | #include <linux/vmalloc.h> |
a56dbddf | 81 | #include <linux/workqueue.h> |
f528f0b8 | 82 | #include <linux/kmemleak.h> |
e9caf1e1 | 83 | #include <linux/sched.h> |
fbf59bc9 TH |
84 | |
85 | #include <asm/cacheflush.h> | |
e0100983 | 86 | #include <asm/sections.h> |
fbf59bc9 | 87 | #include <asm/tlbflush.h> |
3b034b0d | 88 | #include <asm/io.h> |
fbf59bc9 | 89 | |
df95e795 DZ |
90 | #define CREATE_TRACE_POINTS |
91 | #include <trace/events/percpu.h> | |
92 | ||
8fa3ed80 DZ |
93 | #include "percpu-internal.h" |
94 | ||
40064aec DZF |
95 | /* the slots are sorted by free bytes left, 1-31 bytes share the same slot */ |
96 | #define PCPU_SLOT_BASE_SHIFT 5 | |
97 | ||
1a4d7607 TH |
98 | #define PCPU_EMPTY_POP_PAGES_LOW 2 |
99 | #define PCPU_EMPTY_POP_PAGES_HIGH 4 | |
fbf59bc9 | 100 | |
bbddff05 | 101 | #ifdef CONFIG_SMP |
e0100983 TH |
102 | /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ |
103 | #ifndef __addr_to_pcpu_ptr | |
104 | #define __addr_to_pcpu_ptr(addr) \ | |
43cf38eb TH |
105 | (void __percpu *)((unsigned long)(addr) - \ |
106 | (unsigned long)pcpu_base_addr + \ | |
107 | (unsigned long)__per_cpu_start) | |
e0100983 TH |
108 | #endif |
109 | #ifndef __pcpu_ptr_to_addr | |
110 | #define __pcpu_ptr_to_addr(ptr) \ | |
43cf38eb TH |
111 | (void __force *)((unsigned long)(ptr) + \ |
112 | (unsigned long)pcpu_base_addr - \ | |
113 | (unsigned long)__per_cpu_start) | |
e0100983 | 114 | #endif |
bbddff05 TH |
115 | #else /* CONFIG_SMP */ |
116 | /* on UP, it's always identity mapped */ | |
117 | #define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr) | |
118 | #define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr) | |
119 | #endif /* CONFIG_SMP */ | |
e0100983 | 120 | |
1328710b DM |
121 | static int pcpu_unit_pages __ro_after_init; |
122 | static int pcpu_unit_size __ro_after_init; | |
123 | static int pcpu_nr_units __ro_after_init; | |
124 | static int pcpu_atom_size __ro_after_init; | |
8fa3ed80 | 125 | int pcpu_nr_slots __ro_after_init; |
1328710b | 126 | static size_t pcpu_chunk_struct_size __ro_after_init; |
fbf59bc9 | 127 | |
a855b84c | 128 | /* cpus with the lowest and highest unit addresses */ |
1328710b DM |
129 | static unsigned int pcpu_low_unit_cpu __ro_after_init; |
130 | static unsigned int pcpu_high_unit_cpu __ro_after_init; | |
2f39e637 | 131 | |
fbf59bc9 | 132 | /* the address of the first chunk which starts with the kernel static area */ |
1328710b | 133 | void *pcpu_base_addr __ro_after_init; |
fbf59bc9 TH |
134 | EXPORT_SYMBOL_GPL(pcpu_base_addr); |
135 | ||
1328710b DM |
136 | static const int *pcpu_unit_map __ro_after_init; /* cpu -> unit */ |
137 | const unsigned long *pcpu_unit_offsets __ro_after_init; /* cpu -> unit offset */ | |
2f39e637 | 138 | |
6563297c | 139 | /* group information, used for vm allocation */ |
1328710b DM |
140 | static int pcpu_nr_groups __ro_after_init; |
141 | static const unsigned long *pcpu_group_offsets __ro_after_init; | |
142 | static const size_t *pcpu_group_sizes __ro_after_init; | |
6563297c | 143 | |
ae9e6bc9 TH |
144 | /* |
145 | * The first chunk which always exists. Note that unlike other | |
146 | * chunks, this one can be allocated and mapped in several different | |
147 | * ways and thus often doesn't live in the vmalloc area. | |
148 | */ | |
8fa3ed80 | 149 | struct pcpu_chunk *pcpu_first_chunk __ro_after_init; |
ae9e6bc9 TH |
150 | |
151 | /* | |
152 | * Optional reserved chunk. This chunk reserves part of the first | |
e2266705 DZF |
153 | * chunk and serves it for reserved allocations. When the reserved |
154 | * region doesn't exist, the following variable is NULL. | |
ae9e6bc9 | 155 | */ |
8fa3ed80 | 156 | struct pcpu_chunk *pcpu_reserved_chunk __ro_after_init; |
edcb4639 | 157 | |
8fa3ed80 | 158 | DEFINE_SPINLOCK(pcpu_lock); /* all internal data structures */ |
6710e594 | 159 | static DEFINE_MUTEX(pcpu_alloc_mutex); /* chunk create/destroy, [de]pop, map ext */ |
fbf59bc9 | 160 | |
8fa3ed80 | 161 | struct list_head *pcpu_slot __ro_after_init; /* chunk list slots */ |
fbf59bc9 | 162 | |
4f996e23 TH |
163 | /* chunks which need their map areas extended, protected by pcpu_lock */ |
164 | static LIST_HEAD(pcpu_map_extend_chunks); | |
165 | ||
b539b87f TH |
166 | /* |
167 | * The number of empty populated pages, protected by pcpu_lock. The | |
168 | * reserved chunk doesn't contribute to the count. | |
169 | */ | |
6b9b6f39 | 170 | int pcpu_nr_empty_pop_pages; |
b539b87f | 171 | |
1a4d7607 TH |
172 | /* |
173 | * Balance work is used to populate or destroy chunks asynchronously. We | |
174 | * try to keep the number of populated free pages between | |
175 | * PCPU_EMPTY_POP_PAGES_LOW and HIGH for atomic allocations and at most one | |
176 | * empty chunk. | |
177 | */ | |
fe6bd8c3 TH |
178 | static void pcpu_balance_workfn(struct work_struct *work); |
179 | static DECLARE_WORK(pcpu_balance_work, pcpu_balance_workfn); | |
1a4d7607 TH |
180 | static bool pcpu_async_enabled __read_mostly; |
181 | static bool pcpu_atomic_alloc_failed; | |
182 | ||
183 | static void pcpu_schedule_balance_work(void) | |
184 | { | |
185 | if (pcpu_async_enabled) | |
186 | schedule_work(&pcpu_balance_work); | |
187 | } | |
a56dbddf | 188 | |
c0ebfdc3 | 189 | /** |
560f2c23 DZF |
190 | * pcpu_addr_in_chunk - check if the address is served from this chunk |
191 | * @chunk: chunk of interest | |
192 | * @addr: percpu address | |
c0ebfdc3 DZF |
193 | * |
194 | * RETURNS: | |
560f2c23 | 195 | * True if the address is served from this chunk. |
c0ebfdc3 | 196 | */ |
560f2c23 | 197 | static bool pcpu_addr_in_chunk(struct pcpu_chunk *chunk, void *addr) |
020ec653 | 198 | { |
c0ebfdc3 DZF |
199 | void *start_addr, *end_addr; |
200 | ||
560f2c23 | 201 | if (!chunk) |
c0ebfdc3 | 202 | return false; |
020ec653 | 203 | |
560f2c23 DZF |
204 | start_addr = chunk->base_addr + chunk->start_offset; |
205 | end_addr = chunk->base_addr + chunk->nr_pages * PAGE_SIZE - | |
206 | chunk->end_offset; | |
c0ebfdc3 DZF |
207 | |
208 | return addr >= start_addr && addr < end_addr; | |
020ec653 TH |
209 | } |
210 | ||
d9b55eeb | 211 | static int __pcpu_size_to_slot(int size) |
fbf59bc9 | 212 | { |
cae3aeb8 | 213 | int highbit = fls(size); /* size is in bytes */ |
fbf59bc9 TH |
214 | return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); |
215 | } | |
216 | ||
d9b55eeb TH |
217 | static int pcpu_size_to_slot(int size) |
218 | { | |
219 | if (size == pcpu_unit_size) | |
220 | return pcpu_nr_slots - 1; | |
221 | return __pcpu_size_to_slot(size); | |
222 | } | |
223 | ||
fbf59bc9 TH |
224 | static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) |
225 | { | |
40064aec | 226 | if (chunk->free_bytes < PCPU_MIN_ALLOC_SIZE || chunk->contig_bits == 0) |
fbf59bc9 TH |
227 | return 0; |
228 | ||
40064aec | 229 | return pcpu_size_to_slot(chunk->free_bytes); |
fbf59bc9 TH |
230 | } |
231 | ||
88999a89 TH |
232 | /* set the pointer to a chunk in a page struct */ |
233 | static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) | |
234 | { | |
235 | page->index = (unsigned long)pcpu; | |
236 | } | |
237 | ||
238 | /* obtain pointer to a chunk from a page struct */ | |
239 | static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) | |
240 | { | |
241 | return (struct pcpu_chunk *)page->index; | |
242 | } | |
243 | ||
244 | static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) | |
fbf59bc9 | 245 | { |
2f39e637 | 246 | return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; |
fbf59bc9 TH |
247 | } |
248 | ||
c0ebfdc3 DZF |
249 | static unsigned long pcpu_unit_page_offset(unsigned int cpu, int page_idx) |
250 | { | |
251 | return pcpu_unit_offsets[cpu] + (page_idx << PAGE_SHIFT); | |
252 | } | |
253 | ||
9983b6f0 TH |
254 | static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, |
255 | unsigned int cpu, int page_idx) | |
fbf59bc9 | 256 | { |
c0ebfdc3 DZF |
257 | return (unsigned long)chunk->base_addr + |
258 | pcpu_unit_page_offset(cpu, page_idx); | |
fbf59bc9 TH |
259 | } |
260 | ||
91e914c5 | 261 | static void pcpu_next_unpop(unsigned long *bitmap, int *rs, int *re, int end) |
ce3141a2 | 262 | { |
91e914c5 DZF |
263 | *rs = find_next_zero_bit(bitmap, end, *rs); |
264 | *re = find_next_bit(bitmap, end, *rs + 1); | |
ce3141a2 TH |
265 | } |
266 | ||
91e914c5 | 267 | static void pcpu_next_pop(unsigned long *bitmap, int *rs, int *re, int end) |
ce3141a2 | 268 | { |
91e914c5 DZF |
269 | *rs = find_next_bit(bitmap, end, *rs); |
270 | *re = find_next_zero_bit(bitmap, end, *rs + 1); | |
ce3141a2 TH |
271 | } |
272 | ||
273 | /* | |
91e914c5 DZF |
274 | * Bitmap region iterators. Iterates over the bitmap between |
275 | * [@start, @end) in @chunk. @rs and @re should be integer variables | |
276 | * and will be set to start and end index of the current free region. | |
ce3141a2 | 277 | */ |
91e914c5 DZF |
278 | #define pcpu_for_each_unpop_region(bitmap, rs, re, start, end) \ |
279 | for ((rs) = (start), pcpu_next_unpop((bitmap), &(rs), &(re), (end)); \ | |
280 | (rs) < (re); \ | |
281 | (rs) = (re) + 1, pcpu_next_unpop((bitmap), &(rs), &(re), (end))) | |
ce3141a2 | 282 | |
91e914c5 DZF |
283 | #define pcpu_for_each_pop_region(bitmap, rs, re, start, end) \ |
284 | for ((rs) = (start), pcpu_next_pop((bitmap), &(rs), &(re), (end)); \ | |
285 | (rs) < (re); \ | |
286 | (rs) = (re) + 1, pcpu_next_pop((bitmap), &(rs), &(re), (end))) | |
ce3141a2 | 287 | |
ca460b3c DZF |
288 | /* |
289 | * The following are helper functions to help access bitmaps and convert | |
290 | * between bitmap offsets to address offsets. | |
291 | */ | |
292 | static unsigned long *pcpu_index_alloc_map(struct pcpu_chunk *chunk, int index) | |
293 | { | |
294 | return chunk->alloc_map + | |
295 | (index * PCPU_BITMAP_BLOCK_BITS / BITS_PER_LONG); | |
296 | } | |
297 | ||
298 | static unsigned long pcpu_off_to_block_index(int off) | |
299 | { | |
300 | return off / PCPU_BITMAP_BLOCK_BITS; | |
301 | } | |
302 | ||
303 | static unsigned long pcpu_off_to_block_off(int off) | |
304 | { | |
305 | return off & (PCPU_BITMAP_BLOCK_BITS - 1); | |
306 | } | |
307 | ||
b185cd0d DZF |
308 | static unsigned long pcpu_block_off_to_off(int index, int off) |
309 | { | |
310 | return index * PCPU_BITMAP_BLOCK_BITS + off; | |
311 | } | |
312 | ||
525ca84d DZF |
313 | /** |
314 | * pcpu_next_md_free_region - finds the next hint free area | |
315 | * @chunk: chunk of interest | |
316 | * @bit_off: chunk offset | |
317 | * @bits: size of free area | |
318 | * | |
319 | * Helper function for pcpu_for_each_md_free_region. It checks | |
320 | * block->contig_hint and performs aggregation across blocks to find the | |
321 | * next hint. It modifies bit_off and bits in-place to be consumed in the | |
322 | * loop. | |
323 | */ | |
324 | static void pcpu_next_md_free_region(struct pcpu_chunk *chunk, int *bit_off, | |
325 | int *bits) | |
326 | { | |
327 | int i = pcpu_off_to_block_index(*bit_off); | |
328 | int block_off = pcpu_off_to_block_off(*bit_off); | |
329 | struct pcpu_block_md *block; | |
330 | ||
331 | *bits = 0; | |
332 | for (block = chunk->md_blocks + i; i < pcpu_chunk_nr_blocks(chunk); | |
333 | block++, i++) { | |
334 | /* handles contig area across blocks */ | |
335 | if (*bits) { | |
336 | *bits += block->left_free; | |
337 | if (block->left_free == PCPU_BITMAP_BLOCK_BITS) | |
338 | continue; | |
339 | return; | |
340 | } | |
341 | ||
342 | /* | |
343 | * This checks three things. First is there a contig_hint to | |
344 | * check. Second, have we checked this hint before by | |
345 | * comparing the block_off. Third, is this the same as the | |
346 | * right contig hint. In the last case, it spills over into | |
347 | * the next block and should be handled by the contig area | |
348 | * across blocks code. | |
349 | */ | |
350 | *bits = block->contig_hint; | |
351 | if (*bits && block->contig_hint_start >= block_off && | |
352 | *bits + block->contig_hint_start < PCPU_BITMAP_BLOCK_BITS) { | |
353 | *bit_off = pcpu_block_off_to_off(i, | |
354 | block->contig_hint_start); | |
355 | return; | |
356 | } | |
1fa4df3e DZ |
357 | /* reset to satisfy the second predicate above */ |
358 | block_off = 0; | |
525ca84d DZF |
359 | |
360 | *bits = block->right_free; | |
361 | *bit_off = (i + 1) * PCPU_BITMAP_BLOCK_BITS - block->right_free; | |
362 | } | |
363 | } | |
364 | ||
b4c2116c DZF |
365 | /** |
366 | * pcpu_next_fit_region - finds fit areas for a given allocation request | |
367 | * @chunk: chunk of interest | |
368 | * @alloc_bits: size of allocation | |
369 | * @align: alignment of area (max PAGE_SIZE) | |
370 | * @bit_off: chunk offset | |
371 | * @bits: size of free area | |
372 | * | |
373 | * Finds the next free region that is viable for use with a given size and | |
374 | * alignment. This only returns if there is a valid area to be used for this | |
375 | * allocation. block->first_free is returned if the allocation request fits | |
376 | * within the block to see if the request can be fulfilled prior to the contig | |
377 | * hint. | |
378 | */ | |
379 | static void pcpu_next_fit_region(struct pcpu_chunk *chunk, int alloc_bits, | |
380 | int align, int *bit_off, int *bits) | |
381 | { | |
382 | int i = pcpu_off_to_block_index(*bit_off); | |
383 | int block_off = pcpu_off_to_block_off(*bit_off); | |
384 | struct pcpu_block_md *block; | |
385 | ||
386 | *bits = 0; | |
387 | for (block = chunk->md_blocks + i; i < pcpu_chunk_nr_blocks(chunk); | |
388 | block++, i++) { | |
389 | /* handles contig area across blocks */ | |
390 | if (*bits) { | |
391 | *bits += block->left_free; | |
392 | if (*bits >= alloc_bits) | |
393 | return; | |
394 | if (block->left_free == PCPU_BITMAP_BLOCK_BITS) | |
395 | continue; | |
396 | } | |
397 | ||
398 | /* check block->contig_hint */ | |
399 | *bits = ALIGN(block->contig_hint_start, align) - | |
400 | block->contig_hint_start; | |
401 | /* | |
402 | * This uses the block offset to determine if this has been | |
403 | * checked in the prior iteration. | |
404 | */ | |
405 | if (block->contig_hint && | |
406 | block->contig_hint_start >= block_off && | |
407 | block->contig_hint >= *bits + alloc_bits) { | |
408 | *bits += alloc_bits + block->contig_hint_start - | |
409 | block->first_free; | |
410 | *bit_off = pcpu_block_off_to_off(i, block->first_free); | |
411 | return; | |
412 | } | |
1fa4df3e DZ |
413 | /* reset to satisfy the second predicate above */ |
414 | block_off = 0; | |
b4c2116c DZF |
415 | |
416 | *bit_off = ALIGN(PCPU_BITMAP_BLOCK_BITS - block->right_free, | |
417 | align); | |
418 | *bits = PCPU_BITMAP_BLOCK_BITS - *bit_off; | |
419 | *bit_off = pcpu_block_off_to_off(i, *bit_off); | |
420 | if (*bits >= alloc_bits) | |
421 | return; | |
422 | } | |
423 | ||
424 | /* no valid offsets were found - fail condition */ | |
425 | *bit_off = pcpu_chunk_map_bits(chunk); | |
426 | } | |
427 | ||
525ca84d DZF |
428 | /* |
429 | * Metadata free area iterators. These perform aggregation of free areas | |
430 | * based on the metadata blocks and return the offset @bit_off and size in | |
b4c2116c DZF |
431 | * bits of the free area @bits. pcpu_for_each_fit_region only returns when |
432 | * a fit is found for the allocation request. | |
525ca84d DZF |
433 | */ |
434 | #define pcpu_for_each_md_free_region(chunk, bit_off, bits) \ | |
435 | for (pcpu_next_md_free_region((chunk), &(bit_off), &(bits)); \ | |
436 | (bit_off) < pcpu_chunk_map_bits((chunk)); \ | |
437 | (bit_off) += (bits) + 1, \ | |
438 | pcpu_next_md_free_region((chunk), &(bit_off), &(bits))) | |
439 | ||
b4c2116c DZF |
440 | #define pcpu_for_each_fit_region(chunk, alloc_bits, align, bit_off, bits) \ |
441 | for (pcpu_next_fit_region((chunk), (alloc_bits), (align), &(bit_off), \ | |
442 | &(bits)); \ | |
443 | (bit_off) < pcpu_chunk_map_bits((chunk)); \ | |
444 | (bit_off) += (bits), \ | |
445 | pcpu_next_fit_region((chunk), (alloc_bits), (align), &(bit_off), \ | |
446 | &(bits))) | |
447 | ||
fbf59bc9 | 448 | /** |
90459ce0 | 449 | * pcpu_mem_zalloc - allocate memory |
1880d93b | 450 | * @size: bytes to allocate |
72682b16 | 451 | * @gfp: allocation flags |
fbf59bc9 | 452 | * |
1880d93b | 453 | * Allocate @size bytes. If @size is smaller than PAGE_SIZE, |
72682b16 DZ |
454 | * kzalloc() is used; otherwise, the equivalent of vzalloc() is used. |
455 | * This is to facilitate passing through whitelisted flags. The | |
456 | * returned memory is always zeroed. | |
fbf59bc9 | 457 | * |
ccea34b5 TH |
458 | * CONTEXT: |
459 | * Does GFP_KERNEL allocation. | |
460 | * | |
fbf59bc9 | 461 | * RETURNS: |
1880d93b | 462 | * Pointer to the allocated area on success, NULL on failure. |
fbf59bc9 | 463 | */ |
72682b16 | 464 | static void *pcpu_mem_zalloc(size_t size, gfp_t gfp) |
fbf59bc9 | 465 | { |
099a19d9 TH |
466 | if (WARN_ON_ONCE(!slab_is_available())) |
467 | return NULL; | |
468 | ||
1880d93b | 469 | if (size <= PAGE_SIZE) |
72682b16 | 470 | return kzalloc(size, gfp | GFP_KERNEL); |
7af4c093 | 471 | else |
72682b16 DZ |
472 | return __vmalloc(size, gfp | GFP_KERNEL | __GFP_ZERO, |
473 | PAGE_KERNEL); | |
1880d93b | 474 | } |
fbf59bc9 | 475 | |
1880d93b TH |
476 | /** |
477 | * pcpu_mem_free - free memory | |
478 | * @ptr: memory to free | |
1880d93b | 479 | * |
90459ce0 | 480 | * Free @ptr. @ptr should have been allocated using pcpu_mem_zalloc(). |
1880d93b | 481 | */ |
1d5cfdb0 | 482 | static void pcpu_mem_free(void *ptr) |
1880d93b | 483 | { |
1d5cfdb0 | 484 | kvfree(ptr); |
fbf59bc9 TH |
485 | } |
486 | ||
487 | /** | |
488 | * pcpu_chunk_relocate - put chunk in the appropriate chunk slot | |
489 | * @chunk: chunk of interest | |
490 | * @oslot: the previous slot it was on | |
491 | * | |
492 | * This function is called after an allocation or free changed @chunk. | |
493 | * New slot according to the changed state is determined and @chunk is | |
edcb4639 TH |
494 | * moved to the slot. Note that the reserved chunk is never put on |
495 | * chunk slots. | |
ccea34b5 TH |
496 | * |
497 | * CONTEXT: | |
498 | * pcpu_lock. | |
fbf59bc9 TH |
499 | */ |
500 | static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) | |
501 | { | |
502 | int nslot = pcpu_chunk_slot(chunk); | |
503 | ||
edcb4639 | 504 | if (chunk != pcpu_reserved_chunk && oslot != nslot) { |
fbf59bc9 TH |
505 | if (oslot < nslot) |
506 | list_move(&chunk->list, &pcpu_slot[nslot]); | |
507 | else | |
508 | list_move_tail(&chunk->list, &pcpu_slot[nslot]); | |
509 | } | |
510 | } | |
511 | ||
9f7dcf22 | 512 | /** |
40064aec | 513 | * pcpu_cnt_pop_pages- counts populated backing pages in range |
833af842 | 514 | * @chunk: chunk of interest |
40064aec DZF |
515 | * @bit_off: start offset |
516 | * @bits: size of area to check | |
9f7dcf22 | 517 | * |
40064aec DZF |
518 | * Calculates the number of populated pages in the region |
519 | * [page_start, page_end). This keeps track of how many empty populated | |
520 | * pages are available and decide if async work should be scheduled. | |
ccea34b5 | 521 | * |
9f7dcf22 | 522 | * RETURNS: |
40064aec | 523 | * The nr of populated pages. |
9f7dcf22 | 524 | */ |
40064aec DZF |
525 | static inline int pcpu_cnt_pop_pages(struct pcpu_chunk *chunk, int bit_off, |
526 | int bits) | |
9f7dcf22 | 527 | { |
40064aec DZF |
528 | int page_start = PFN_UP(bit_off * PCPU_MIN_ALLOC_SIZE); |
529 | int page_end = PFN_DOWN((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); | |
4f996e23 | 530 | |
40064aec | 531 | if (page_start >= page_end) |
9f7dcf22 TH |
532 | return 0; |
533 | ||
40064aec DZF |
534 | /* |
535 | * bitmap_weight counts the number of bits set in a bitmap up to | |
536 | * the specified number of bits. This is counting the populated | |
537 | * pages up to page_end and then subtracting the populated pages | |
538 | * up to page_start to count the populated pages in | |
539 | * [page_start, page_end). | |
540 | */ | |
541 | return bitmap_weight(chunk->populated, page_end) - | |
542 | bitmap_weight(chunk->populated, page_start); | |
833af842 TH |
543 | } |
544 | ||
545 | /** | |
40064aec | 546 | * pcpu_chunk_update - updates the chunk metadata given a free area |
833af842 | 547 | * @chunk: chunk of interest |
40064aec DZF |
548 | * @bit_off: chunk offset |
549 | * @bits: size of free area | |
833af842 | 550 | * |
13f96637 | 551 | * This updates the chunk's contig hint and starting offset given a free area. |
268625a6 | 552 | * Choose the best starting offset if the contig hint is equal. |
40064aec DZF |
553 | */ |
554 | static void pcpu_chunk_update(struct pcpu_chunk *chunk, int bit_off, int bits) | |
555 | { | |
13f96637 DZF |
556 | if (bits > chunk->contig_bits) { |
557 | chunk->contig_bits_start = bit_off; | |
40064aec | 558 | chunk->contig_bits = bits; |
268625a6 DZF |
559 | } else if (bits == chunk->contig_bits && chunk->contig_bits_start && |
560 | (!bit_off || | |
561 | __ffs(bit_off) > __ffs(chunk->contig_bits_start))) { | |
562 | /* use the start with the best alignment */ | |
563 | chunk->contig_bits_start = bit_off; | |
13f96637 | 564 | } |
40064aec DZF |
565 | } |
566 | ||
567 | /** | |
568 | * pcpu_chunk_refresh_hint - updates metadata about a chunk | |
569 | * @chunk: chunk of interest | |
833af842 | 570 | * |
525ca84d DZF |
571 | * Iterates over the metadata blocks to find the largest contig area. |
572 | * It also counts the populated pages and uses the delta to update the | |
573 | * global count. | |
833af842 | 574 | * |
40064aec DZF |
575 | * Updates: |
576 | * chunk->contig_bits | |
13f96637 | 577 | * chunk->contig_bits_start |
525ca84d | 578 | * nr_empty_pop_pages (chunk and global) |
833af842 | 579 | */ |
40064aec | 580 | static void pcpu_chunk_refresh_hint(struct pcpu_chunk *chunk) |
833af842 | 581 | { |
525ca84d | 582 | int bit_off, bits, nr_empty_pop_pages; |
833af842 | 583 | |
40064aec DZF |
584 | /* clear metadata */ |
585 | chunk->contig_bits = 0; | |
6710e594 | 586 | |
525ca84d | 587 | bit_off = chunk->first_bit; |
40064aec | 588 | bits = nr_empty_pop_pages = 0; |
525ca84d DZF |
589 | pcpu_for_each_md_free_region(chunk, bit_off, bits) { |
590 | pcpu_chunk_update(chunk, bit_off, bits); | |
833af842 | 591 | |
525ca84d | 592 | nr_empty_pop_pages += pcpu_cnt_pop_pages(chunk, bit_off, bits); |
40064aec | 593 | } |
9f7dcf22 | 594 | |
40064aec DZF |
595 | /* |
596 | * Keep track of nr_empty_pop_pages. | |
597 | * | |
598 | * The chunk maintains the previous number of free pages it held, | |
599 | * so the delta is used to update the global counter. The reserved | |
600 | * chunk is not part of the free page count as they are populated | |
601 | * at init and are special to serving reserved allocations. | |
602 | */ | |
603 | if (chunk != pcpu_reserved_chunk) | |
604 | pcpu_nr_empty_pop_pages += | |
605 | (nr_empty_pop_pages - chunk->nr_empty_pop_pages); | |
a002d148 | 606 | |
40064aec DZF |
607 | chunk->nr_empty_pop_pages = nr_empty_pop_pages; |
608 | } | |
9f7dcf22 | 609 | |
ca460b3c DZF |
610 | /** |
611 | * pcpu_block_update - updates a block given a free area | |
612 | * @block: block of interest | |
613 | * @start: start offset in block | |
614 | * @end: end offset in block | |
615 | * | |
616 | * Updates a block given a known free area. The region [start, end) is | |
268625a6 DZF |
617 | * expected to be the entirety of the free area within a block. Chooses |
618 | * the best starting offset if the contig hints are equal. | |
ca460b3c DZF |
619 | */ |
620 | static void pcpu_block_update(struct pcpu_block_md *block, int start, int end) | |
621 | { | |
622 | int contig = end - start; | |
623 | ||
624 | block->first_free = min(block->first_free, start); | |
625 | if (start == 0) | |
626 | block->left_free = contig; | |
627 | ||
628 | if (end == PCPU_BITMAP_BLOCK_BITS) | |
629 | block->right_free = contig; | |
630 | ||
631 | if (contig > block->contig_hint) { | |
632 | block->contig_hint_start = start; | |
633 | block->contig_hint = contig; | |
268625a6 DZF |
634 | } else if (block->contig_hint_start && contig == block->contig_hint && |
635 | (!start || __ffs(start) > __ffs(block->contig_hint_start))) { | |
636 | /* use the start with the best alignment */ | |
637 | block->contig_hint_start = start; | |
ca460b3c DZF |
638 | } |
639 | } | |
640 | ||
641 | /** | |
642 | * pcpu_block_refresh_hint | |
643 | * @chunk: chunk of interest | |
644 | * @index: index of the metadata block | |
645 | * | |
646 | * Scans over the block beginning at first_free and updates the block | |
647 | * metadata accordingly. | |
648 | */ | |
649 | static void pcpu_block_refresh_hint(struct pcpu_chunk *chunk, int index) | |
650 | { | |
651 | struct pcpu_block_md *block = chunk->md_blocks + index; | |
652 | unsigned long *alloc_map = pcpu_index_alloc_map(chunk, index); | |
653 | int rs, re; /* region start, region end */ | |
654 | ||
655 | /* clear hints */ | |
656 | block->contig_hint = 0; | |
657 | block->left_free = block->right_free = 0; | |
658 | ||
659 | /* iterate over free areas and update the contig hints */ | |
660 | pcpu_for_each_unpop_region(alloc_map, rs, re, block->first_free, | |
661 | PCPU_BITMAP_BLOCK_BITS) { | |
662 | pcpu_block_update(block, rs, re); | |
663 | } | |
664 | } | |
665 | ||
666 | /** | |
667 | * pcpu_block_update_hint_alloc - update hint on allocation path | |
668 | * @chunk: chunk of interest | |
669 | * @bit_off: chunk offset | |
670 | * @bits: size of request | |
fc304334 DZF |
671 | * |
672 | * Updates metadata for the allocation path. The metadata only has to be | |
673 | * refreshed by a full scan iff the chunk's contig hint is broken. Block level | |
674 | * scans are required if the block's contig hint is broken. | |
ca460b3c DZF |
675 | */ |
676 | static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, | |
677 | int bits) | |
678 | { | |
679 | struct pcpu_block_md *s_block, *e_block, *block; | |
680 | int s_index, e_index; /* block indexes of the freed allocation */ | |
681 | int s_off, e_off; /* block offsets of the freed allocation */ | |
682 | ||
683 | /* | |
684 | * Calculate per block offsets. | |
685 | * The calculation uses an inclusive range, but the resulting offsets | |
686 | * are [start, end). e_index always points to the last block in the | |
687 | * range. | |
688 | */ | |
689 | s_index = pcpu_off_to_block_index(bit_off); | |
690 | e_index = pcpu_off_to_block_index(bit_off + bits - 1); | |
691 | s_off = pcpu_off_to_block_off(bit_off); | |
692 | e_off = pcpu_off_to_block_off(bit_off + bits - 1) + 1; | |
693 | ||
694 | s_block = chunk->md_blocks + s_index; | |
695 | e_block = chunk->md_blocks + e_index; | |
696 | ||
697 | /* | |
698 | * Update s_block. | |
fc304334 DZF |
699 | * block->first_free must be updated if the allocation takes its place. |
700 | * If the allocation breaks the contig_hint, a scan is required to | |
701 | * restore this hint. | |
ca460b3c | 702 | */ |
fc304334 DZF |
703 | if (s_off == s_block->first_free) |
704 | s_block->first_free = find_next_zero_bit( | |
705 | pcpu_index_alloc_map(chunk, s_index), | |
706 | PCPU_BITMAP_BLOCK_BITS, | |
707 | s_off + bits); | |
708 | ||
709 | if (s_off >= s_block->contig_hint_start && | |
710 | s_off < s_block->contig_hint_start + s_block->contig_hint) { | |
711 | /* block contig hint is broken - scan to fix it */ | |
712 | pcpu_block_refresh_hint(chunk, s_index); | |
713 | } else { | |
714 | /* update left and right contig manually */ | |
715 | s_block->left_free = min(s_block->left_free, s_off); | |
716 | if (s_index == e_index) | |
717 | s_block->right_free = min_t(int, s_block->right_free, | |
718 | PCPU_BITMAP_BLOCK_BITS - e_off); | |
719 | else | |
720 | s_block->right_free = 0; | |
721 | } | |
ca460b3c DZF |
722 | |
723 | /* | |
724 | * Update e_block. | |
725 | */ | |
726 | if (s_index != e_index) { | |
fc304334 DZF |
727 | /* |
728 | * When the allocation is across blocks, the end is along | |
729 | * the left part of the e_block. | |
730 | */ | |
731 | e_block->first_free = find_next_zero_bit( | |
732 | pcpu_index_alloc_map(chunk, e_index), | |
733 | PCPU_BITMAP_BLOCK_BITS, e_off); | |
734 | ||
735 | if (e_off == PCPU_BITMAP_BLOCK_BITS) { | |
736 | /* reset the block */ | |
737 | e_block++; | |
738 | } else { | |
739 | if (e_off > e_block->contig_hint_start) { | |
740 | /* contig hint is broken - scan to fix it */ | |
741 | pcpu_block_refresh_hint(chunk, e_index); | |
742 | } else { | |
743 | e_block->left_free = 0; | |
744 | e_block->right_free = | |
745 | min_t(int, e_block->right_free, | |
746 | PCPU_BITMAP_BLOCK_BITS - e_off); | |
747 | } | |
748 | } | |
ca460b3c DZF |
749 | |
750 | /* update in-between md_blocks */ | |
751 | for (block = s_block + 1; block < e_block; block++) { | |
752 | block->contig_hint = 0; | |
753 | block->left_free = 0; | |
754 | block->right_free = 0; | |
755 | } | |
756 | } | |
757 | ||
fc304334 DZF |
758 | /* |
759 | * The only time a full chunk scan is required is if the chunk | |
760 | * contig hint is broken. Otherwise, it means a smaller space | |
761 | * was used and therefore the chunk contig hint is still correct. | |
762 | */ | |
763 | if (bit_off >= chunk->contig_bits_start && | |
764 | bit_off < chunk->contig_bits_start + chunk->contig_bits) | |
765 | pcpu_chunk_refresh_hint(chunk); | |
ca460b3c DZF |
766 | } |
767 | ||
768 | /** | |
769 | * pcpu_block_update_hint_free - updates the block hints on the free path | |
770 | * @chunk: chunk of interest | |
771 | * @bit_off: chunk offset | |
772 | * @bits: size of request | |
b185cd0d DZF |
773 | * |
774 | * Updates metadata for the allocation path. This avoids a blind block | |
775 | * refresh by making use of the block contig hints. If this fails, it scans | |
776 | * forward and backward to determine the extent of the free area. This is | |
777 | * capped at the boundary of blocks. | |
778 | * | |
779 | * A chunk update is triggered if a page becomes free, a block becomes free, | |
780 | * or the free spans across blocks. This tradeoff is to minimize iterating | |
781 | * over the block metadata to update chunk->contig_bits. chunk->contig_bits | |
782 | * may be off by up to a page, but it will never be more than the available | |
783 | * space. If the contig hint is contained in one block, it will be accurate. | |
ca460b3c DZF |
784 | */ |
785 | static void pcpu_block_update_hint_free(struct pcpu_chunk *chunk, int bit_off, | |
786 | int bits) | |
787 | { | |
788 | struct pcpu_block_md *s_block, *e_block, *block; | |
789 | int s_index, e_index; /* block indexes of the freed allocation */ | |
790 | int s_off, e_off; /* block offsets of the freed allocation */ | |
b185cd0d | 791 | int start, end; /* start and end of the whole free area */ |
ca460b3c DZF |
792 | |
793 | /* | |
794 | * Calculate per block offsets. | |
795 | * The calculation uses an inclusive range, but the resulting offsets | |
796 | * are [start, end). e_index always points to the last block in the | |
797 | * range. | |
798 | */ | |
799 | s_index = pcpu_off_to_block_index(bit_off); | |
800 | e_index = pcpu_off_to_block_index(bit_off + bits - 1); | |
801 | s_off = pcpu_off_to_block_off(bit_off); | |
802 | e_off = pcpu_off_to_block_off(bit_off + bits - 1) + 1; | |
803 | ||
804 | s_block = chunk->md_blocks + s_index; | |
805 | e_block = chunk->md_blocks + e_index; | |
806 | ||
b185cd0d DZF |
807 | /* |
808 | * Check if the freed area aligns with the block->contig_hint. | |
809 | * If it does, then the scan to find the beginning/end of the | |
810 | * larger free area can be avoided. | |
811 | * | |
812 | * start and end refer to beginning and end of the free area | |
813 | * within each their respective blocks. This is not necessarily | |
814 | * the entire free area as it may span blocks past the beginning | |
815 | * or end of the block. | |
816 | */ | |
817 | start = s_off; | |
818 | if (s_off == s_block->contig_hint + s_block->contig_hint_start) { | |
819 | start = s_block->contig_hint_start; | |
820 | } else { | |
821 | /* | |
822 | * Scan backwards to find the extent of the free area. | |
823 | * find_last_bit returns the starting bit, so if the start bit | |
824 | * is returned, that means there was no last bit and the | |
825 | * remainder of the chunk is free. | |
826 | */ | |
827 | int l_bit = find_last_bit(pcpu_index_alloc_map(chunk, s_index), | |
828 | start); | |
829 | start = (start == l_bit) ? 0 : l_bit + 1; | |
830 | } | |
831 | ||
832 | end = e_off; | |
833 | if (e_off == e_block->contig_hint_start) | |
834 | end = e_block->contig_hint_start + e_block->contig_hint; | |
835 | else | |
836 | end = find_next_bit(pcpu_index_alloc_map(chunk, e_index), | |
837 | PCPU_BITMAP_BLOCK_BITS, end); | |
838 | ||
ca460b3c | 839 | /* update s_block */ |
b185cd0d DZF |
840 | e_off = (s_index == e_index) ? end : PCPU_BITMAP_BLOCK_BITS; |
841 | pcpu_block_update(s_block, start, e_off); | |
ca460b3c DZF |
842 | |
843 | /* freeing in the same block */ | |
844 | if (s_index != e_index) { | |
845 | /* update e_block */ | |
b185cd0d | 846 | pcpu_block_update(e_block, 0, end); |
ca460b3c DZF |
847 | |
848 | /* reset md_blocks in the middle */ | |
849 | for (block = s_block + 1; block < e_block; block++) { | |
850 | block->first_free = 0; | |
851 | block->contig_hint_start = 0; | |
852 | block->contig_hint = PCPU_BITMAP_BLOCK_BITS; | |
853 | block->left_free = PCPU_BITMAP_BLOCK_BITS; | |
854 | block->right_free = PCPU_BITMAP_BLOCK_BITS; | |
855 | } | |
856 | } | |
857 | ||
b185cd0d DZF |
858 | /* |
859 | * Refresh chunk metadata when the free makes a page free, a block | |
860 | * free, or spans across blocks. The contig hint may be off by up to | |
861 | * a page, but if the hint is contained in a block, it will be accurate | |
862 | * with the else condition below. | |
863 | */ | |
864 | if ((ALIGN_DOWN(end, min(PCPU_BITS_PER_PAGE, PCPU_BITMAP_BLOCK_BITS)) > | |
865 | ALIGN(start, min(PCPU_BITS_PER_PAGE, PCPU_BITMAP_BLOCK_BITS))) || | |
866 | s_index != e_index) | |
867 | pcpu_chunk_refresh_hint(chunk); | |
868 | else | |
869 | pcpu_chunk_update(chunk, pcpu_block_off_to_off(s_index, start), | |
870 | s_block->contig_hint); | |
ca460b3c DZF |
871 | } |
872 | ||
40064aec DZF |
873 | /** |
874 | * pcpu_is_populated - determines if the region is populated | |
875 | * @chunk: chunk of interest | |
876 | * @bit_off: chunk offset | |
877 | * @bits: size of area | |
878 | * @next_off: return value for the next offset to start searching | |
879 | * | |
880 | * For atomic allocations, check if the backing pages are populated. | |
881 | * | |
882 | * RETURNS: | |
883 | * Bool if the backing pages are populated. | |
884 | * next_index is to skip over unpopulated blocks in pcpu_find_block_fit. | |
885 | */ | |
886 | static bool pcpu_is_populated(struct pcpu_chunk *chunk, int bit_off, int bits, | |
887 | int *next_off) | |
888 | { | |
889 | int page_start, page_end, rs, re; | |
833af842 | 890 | |
40064aec DZF |
891 | page_start = PFN_DOWN(bit_off * PCPU_MIN_ALLOC_SIZE); |
892 | page_end = PFN_UP((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); | |
833af842 | 893 | |
40064aec DZF |
894 | rs = page_start; |
895 | pcpu_next_unpop(chunk->populated, &rs, &re, page_end); | |
896 | if (rs >= page_end) | |
897 | return true; | |
833af842 | 898 | |
40064aec DZF |
899 | *next_off = re * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; |
900 | return false; | |
9f7dcf22 TH |
901 | } |
902 | ||
a16037c8 | 903 | /** |
40064aec DZF |
904 | * pcpu_find_block_fit - finds the block index to start searching |
905 | * @chunk: chunk of interest | |
906 | * @alloc_bits: size of request in allocation units | |
907 | * @align: alignment of area (max PAGE_SIZE bytes) | |
908 | * @pop_only: use populated regions only | |
909 | * | |
b4c2116c DZF |
910 | * Given a chunk and an allocation spec, find the offset to begin searching |
911 | * for a free region. This iterates over the bitmap metadata blocks to | |
912 | * find an offset that will be guaranteed to fit the requirements. It is | |
913 | * not quite first fit as if the allocation does not fit in the contig hint | |
914 | * of a block or chunk, it is skipped. This errs on the side of caution | |
915 | * to prevent excess iteration. Poor alignment can cause the allocator to | |
916 | * skip over blocks and chunks that have valid free areas. | |
917 | * | |
40064aec DZF |
918 | * RETURNS: |
919 | * The offset in the bitmap to begin searching. | |
920 | * -1 if no offset is found. | |
a16037c8 | 921 | */ |
40064aec DZF |
922 | static int pcpu_find_block_fit(struct pcpu_chunk *chunk, int alloc_bits, |
923 | size_t align, bool pop_only) | |
a16037c8 | 924 | { |
b4c2116c | 925 | int bit_off, bits, next_off; |
a16037c8 | 926 | |
13f96637 DZF |
927 | /* |
928 | * Check to see if the allocation can fit in the chunk's contig hint. | |
929 | * This is an optimization to prevent scanning by assuming if it | |
930 | * cannot fit in the global hint, there is memory pressure and creating | |
931 | * a new chunk would happen soon. | |
932 | */ | |
933 | bit_off = ALIGN(chunk->contig_bits_start, align) - | |
934 | chunk->contig_bits_start; | |
935 | if (bit_off + alloc_bits > chunk->contig_bits) | |
936 | return -1; | |
937 | ||
b4c2116c DZF |
938 | bit_off = chunk->first_bit; |
939 | bits = 0; | |
940 | pcpu_for_each_fit_region(chunk, alloc_bits, align, bit_off, bits) { | |
40064aec | 941 | if (!pop_only || pcpu_is_populated(chunk, bit_off, bits, |
b4c2116c | 942 | &next_off)) |
40064aec | 943 | break; |
a16037c8 | 944 | |
b4c2116c | 945 | bit_off = next_off; |
40064aec | 946 | bits = 0; |
a16037c8 | 947 | } |
40064aec DZF |
948 | |
949 | if (bit_off == pcpu_chunk_map_bits(chunk)) | |
950 | return -1; | |
951 | ||
952 | return bit_off; | |
a16037c8 TH |
953 | } |
954 | ||
fbf59bc9 | 955 | /** |
40064aec | 956 | * pcpu_alloc_area - allocates an area from a pcpu_chunk |
fbf59bc9 | 957 | * @chunk: chunk of interest |
40064aec DZF |
958 | * @alloc_bits: size of request in allocation units |
959 | * @align: alignment of area (max PAGE_SIZE) | |
960 | * @start: bit_off to start searching | |
9f7dcf22 | 961 | * |
40064aec | 962 | * This function takes in a @start offset to begin searching to fit an |
b4c2116c DZF |
963 | * allocation of @alloc_bits with alignment @align. It needs to scan |
964 | * the allocation map because if it fits within the block's contig hint, | |
965 | * @start will be block->first_free. This is an attempt to fill the | |
966 | * allocation prior to breaking the contig hint. The allocation and | |
967 | * boundary maps are updated accordingly if it confirms a valid | |
968 | * free area. | |
ccea34b5 | 969 | * |
fbf59bc9 | 970 | * RETURNS: |
40064aec DZF |
971 | * Allocated addr offset in @chunk on success. |
972 | * -1 if no matching area is found. | |
fbf59bc9 | 973 | */ |
40064aec DZF |
974 | static int pcpu_alloc_area(struct pcpu_chunk *chunk, int alloc_bits, |
975 | size_t align, int start) | |
fbf59bc9 | 976 | { |
40064aec DZF |
977 | size_t align_mask = (align) ? (align - 1) : 0; |
978 | int bit_off, end, oslot; | |
a16037c8 | 979 | |
40064aec | 980 | lockdep_assert_held(&pcpu_lock); |
fbf59bc9 | 981 | |
40064aec | 982 | oslot = pcpu_chunk_slot(chunk); |
fbf59bc9 | 983 | |
40064aec DZF |
984 | /* |
985 | * Search to find a fit. | |
986 | */ | |
b4c2116c | 987 | end = start + alloc_bits + PCPU_BITMAP_BLOCK_BITS; |
40064aec DZF |
988 | bit_off = bitmap_find_next_zero_area(chunk->alloc_map, end, start, |
989 | alloc_bits, align_mask); | |
990 | if (bit_off >= end) | |
991 | return -1; | |
fbf59bc9 | 992 | |
40064aec DZF |
993 | /* update alloc map */ |
994 | bitmap_set(chunk->alloc_map, bit_off, alloc_bits); | |
3d331ad7 | 995 | |
40064aec DZF |
996 | /* update boundary map */ |
997 | set_bit(bit_off, chunk->bound_map); | |
998 | bitmap_clear(chunk->bound_map, bit_off + 1, alloc_bits - 1); | |
999 | set_bit(bit_off + alloc_bits, chunk->bound_map); | |
fbf59bc9 | 1000 | |
40064aec | 1001 | chunk->free_bytes -= alloc_bits * PCPU_MIN_ALLOC_SIZE; |
fbf59bc9 | 1002 | |
86b442fb DZF |
1003 | /* update first free bit */ |
1004 | if (bit_off == chunk->first_bit) | |
1005 | chunk->first_bit = find_next_zero_bit( | |
1006 | chunk->alloc_map, | |
1007 | pcpu_chunk_map_bits(chunk), | |
1008 | bit_off + alloc_bits); | |
1009 | ||
ca460b3c | 1010 | pcpu_block_update_hint_alloc(chunk, bit_off, alloc_bits); |
fbf59bc9 | 1011 | |
fbf59bc9 TH |
1012 | pcpu_chunk_relocate(chunk, oslot); |
1013 | ||
40064aec | 1014 | return bit_off * PCPU_MIN_ALLOC_SIZE; |
fbf59bc9 TH |
1015 | } |
1016 | ||
1017 | /** | |
40064aec | 1018 | * pcpu_free_area - frees the corresponding offset |
fbf59bc9 | 1019 | * @chunk: chunk of interest |
40064aec | 1020 | * @off: addr offset into chunk |
ccea34b5 | 1021 | * |
40064aec DZF |
1022 | * This function determines the size of an allocation to free using |
1023 | * the boundary bitmap and clears the allocation map. | |
fbf59bc9 | 1024 | */ |
40064aec | 1025 | static void pcpu_free_area(struct pcpu_chunk *chunk, int off) |
fbf59bc9 | 1026 | { |
40064aec | 1027 | int bit_off, bits, end, oslot; |
723ad1d9 | 1028 | |
5ccd30e4 | 1029 | lockdep_assert_held(&pcpu_lock); |
30a5b536 | 1030 | pcpu_stats_area_dealloc(chunk); |
5ccd30e4 | 1031 | |
40064aec | 1032 | oslot = pcpu_chunk_slot(chunk); |
fbf59bc9 | 1033 | |
40064aec | 1034 | bit_off = off / PCPU_MIN_ALLOC_SIZE; |
3d331ad7 | 1035 | |
40064aec DZF |
1036 | /* find end index */ |
1037 | end = find_next_bit(chunk->bound_map, pcpu_chunk_map_bits(chunk), | |
1038 | bit_off + 1); | |
1039 | bits = end - bit_off; | |
1040 | bitmap_clear(chunk->alloc_map, bit_off, bits); | |
fbf59bc9 | 1041 | |
40064aec DZF |
1042 | /* update metadata */ |
1043 | chunk->free_bytes += bits * PCPU_MIN_ALLOC_SIZE; | |
b539b87f | 1044 | |
86b442fb DZF |
1045 | /* update first free bit */ |
1046 | chunk->first_bit = min(chunk->first_bit, bit_off); | |
1047 | ||
ca460b3c | 1048 | pcpu_block_update_hint_free(chunk, bit_off, bits); |
fbf59bc9 | 1049 | |
fbf59bc9 TH |
1050 | pcpu_chunk_relocate(chunk, oslot); |
1051 | } | |
1052 | ||
ca460b3c DZF |
1053 | static void pcpu_init_md_blocks(struct pcpu_chunk *chunk) |
1054 | { | |
1055 | struct pcpu_block_md *md_block; | |
1056 | ||
1057 | for (md_block = chunk->md_blocks; | |
1058 | md_block != chunk->md_blocks + pcpu_chunk_nr_blocks(chunk); | |
1059 | md_block++) { | |
1060 | md_block->contig_hint = PCPU_BITMAP_BLOCK_BITS; | |
1061 | md_block->left_free = PCPU_BITMAP_BLOCK_BITS; | |
1062 | md_block->right_free = PCPU_BITMAP_BLOCK_BITS; | |
1063 | } | |
1064 | } | |
1065 | ||
40064aec DZF |
1066 | /** |
1067 | * pcpu_alloc_first_chunk - creates chunks that serve the first chunk | |
1068 | * @tmp_addr: the start of the region served | |
1069 | * @map_size: size of the region served | |
1070 | * | |
1071 | * This is responsible for creating the chunks that serve the first chunk. The | |
1072 | * base_addr is page aligned down of @tmp_addr while the region end is page | |
1073 | * aligned up. Offsets are kept track of to determine the region served. All | |
1074 | * this is done to appease the bitmap allocator in avoiding partial blocks. | |
1075 | * | |
1076 | * RETURNS: | |
1077 | * Chunk serving the region at @tmp_addr of @map_size. | |
1078 | */ | |
c0ebfdc3 | 1079 | static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr, |
40064aec | 1080 | int map_size) |
10edf5b0 DZF |
1081 | { |
1082 | struct pcpu_chunk *chunk; | |
ca460b3c | 1083 | unsigned long aligned_addr, lcm_align; |
40064aec | 1084 | int start_offset, offset_bits, region_size, region_bits; |
c0ebfdc3 DZF |
1085 | |
1086 | /* region calculations */ | |
1087 | aligned_addr = tmp_addr & PAGE_MASK; | |
1088 | ||
1089 | start_offset = tmp_addr - aligned_addr; | |
6b9d7c8e | 1090 | |
ca460b3c DZF |
1091 | /* |
1092 | * Align the end of the region with the LCM of PAGE_SIZE and | |
1093 | * PCPU_BITMAP_BLOCK_SIZE. One of these constants is a multiple of | |
1094 | * the other. | |
1095 | */ | |
1096 | lcm_align = lcm(PAGE_SIZE, PCPU_BITMAP_BLOCK_SIZE); | |
1097 | region_size = ALIGN(start_offset + map_size, lcm_align); | |
10edf5b0 | 1098 | |
c0ebfdc3 | 1099 | /* allocate chunk */ |
8ab16c43 DZF |
1100 | chunk = memblock_virt_alloc(sizeof(struct pcpu_chunk) + |
1101 | BITS_TO_LONGS(region_size >> PAGE_SHIFT), | |
1102 | 0); | |
c0ebfdc3 | 1103 | |
10edf5b0 | 1104 | INIT_LIST_HEAD(&chunk->list); |
c0ebfdc3 DZF |
1105 | |
1106 | chunk->base_addr = (void *)aligned_addr; | |
10edf5b0 | 1107 | chunk->start_offset = start_offset; |
6b9d7c8e | 1108 | chunk->end_offset = region_size - chunk->start_offset - map_size; |
c0ebfdc3 | 1109 | |
8ab16c43 | 1110 | chunk->nr_pages = region_size >> PAGE_SHIFT; |
40064aec | 1111 | region_bits = pcpu_chunk_map_bits(chunk); |
c0ebfdc3 | 1112 | |
ca460b3c DZF |
1113 | chunk->alloc_map = memblock_virt_alloc(BITS_TO_LONGS(region_bits) * |
1114 | sizeof(chunk->alloc_map[0]), 0); | |
1115 | chunk->bound_map = memblock_virt_alloc(BITS_TO_LONGS(region_bits + 1) * | |
1116 | sizeof(chunk->bound_map[0]), 0); | |
1117 | chunk->md_blocks = memblock_virt_alloc(pcpu_chunk_nr_blocks(chunk) * | |
1118 | sizeof(chunk->md_blocks[0]), 0); | |
1119 | pcpu_init_md_blocks(chunk); | |
10edf5b0 DZF |
1120 | |
1121 | /* manage populated page bitmap */ | |
1122 | chunk->immutable = true; | |
8ab16c43 DZF |
1123 | bitmap_fill(chunk->populated, chunk->nr_pages); |
1124 | chunk->nr_populated = chunk->nr_pages; | |
40064aec DZF |
1125 | chunk->nr_empty_pop_pages = |
1126 | pcpu_cnt_pop_pages(chunk, start_offset / PCPU_MIN_ALLOC_SIZE, | |
1127 | map_size / PCPU_MIN_ALLOC_SIZE); | |
10edf5b0 | 1128 | |
40064aec DZF |
1129 | chunk->contig_bits = map_size / PCPU_MIN_ALLOC_SIZE; |
1130 | chunk->free_bytes = map_size; | |
c0ebfdc3 DZF |
1131 | |
1132 | if (chunk->start_offset) { | |
1133 | /* hide the beginning of the bitmap */ | |
40064aec DZF |
1134 | offset_bits = chunk->start_offset / PCPU_MIN_ALLOC_SIZE; |
1135 | bitmap_set(chunk->alloc_map, 0, offset_bits); | |
1136 | set_bit(0, chunk->bound_map); | |
1137 | set_bit(offset_bits, chunk->bound_map); | |
ca460b3c | 1138 | |
86b442fb DZF |
1139 | chunk->first_bit = offset_bits; |
1140 | ||
ca460b3c | 1141 | pcpu_block_update_hint_alloc(chunk, 0, offset_bits); |
c0ebfdc3 DZF |
1142 | } |
1143 | ||
6b9d7c8e DZF |
1144 | if (chunk->end_offset) { |
1145 | /* hide the end of the bitmap */ | |
40064aec DZF |
1146 | offset_bits = chunk->end_offset / PCPU_MIN_ALLOC_SIZE; |
1147 | bitmap_set(chunk->alloc_map, | |
1148 | pcpu_chunk_map_bits(chunk) - offset_bits, | |
1149 | offset_bits); | |
1150 | set_bit((start_offset + map_size) / PCPU_MIN_ALLOC_SIZE, | |
1151 | chunk->bound_map); | |
1152 | set_bit(region_bits, chunk->bound_map); | |
6b9d7c8e | 1153 | |
ca460b3c DZF |
1154 | pcpu_block_update_hint_alloc(chunk, pcpu_chunk_map_bits(chunk) |
1155 | - offset_bits, offset_bits); | |
1156 | } | |
40064aec | 1157 | |
10edf5b0 DZF |
1158 | return chunk; |
1159 | } | |
1160 | ||
72682b16 | 1161 | static struct pcpu_chunk *pcpu_alloc_chunk(gfp_t gfp) |
6081089f TH |
1162 | { |
1163 | struct pcpu_chunk *chunk; | |
40064aec | 1164 | int region_bits; |
6081089f | 1165 | |
72682b16 | 1166 | chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size, gfp); |
6081089f TH |
1167 | if (!chunk) |
1168 | return NULL; | |
1169 | ||
40064aec DZF |
1170 | INIT_LIST_HEAD(&chunk->list); |
1171 | chunk->nr_pages = pcpu_unit_pages; | |
1172 | region_bits = pcpu_chunk_map_bits(chunk); | |
6081089f | 1173 | |
40064aec | 1174 | chunk->alloc_map = pcpu_mem_zalloc(BITS_TO_LONGS(region_bits) * |
72682b16 | 1175 | sizeof(chunk->alloc_map[0]), gfp); |
40064aec DZF |
1176 | if (!chunk->alloc_map) |
1177 | goto alloc_map_fail; | |
6081089f | 1178 | |
40064aec | 1179 | chunk->bound_map = pcpu_mem_zalloc(BITS_TO_LONGS(region_bits + 1) * |
72682b16 | 1180 | sizeof(chunk->bound_map[0]), gfp); |
40064aec DZF |
1181 | if (!chunk->bound_map) |
1182 | goto bound_map_fail; | |
6081089f | 1183 | |
ca460b3c | 1184 | chunk->md_blocks = pcpu_mem_zalloc(pcpu_chunk_nr_blocks(chunk) * |
72682b16 | 1185 | sizeof(chunk->md_blocks[0]), gfp); |
ca460b3c DZF |
1186 | if (!chunk->md_blocks) |
1187 | goto md_blocks_fail; | |
1188 | ||
1189 | pcpu_init_md_blocks(chunk); | |
1190 | ||
40064aec DZF |
1191 | /* init metadata */ |
1192 | chunk->contig_bits = region_bits; | |
1193 | chunk->free_bytes = chunk->nr_pages * PAGE_SIZE; | |
c0ebfdc3 | 1194 | |
6081089f | 1195 | return chunk; |
40064aec | 1196 | |
ca460b3c DZF |
1197 | md_blocks_fail: |
1198 | pcpu_mem_free(chunk->bound_map); | |
40064aec DZF |
1199 | bound_map_fail: |
1200 | pcpu_mem_free(chunk->alloc_map); | |
1201 | alloc_map_fail: | |
1202 | pcpu_mem_free(chunk); | |
1203 | ||
1204 | return NULL; | |
6081089f TH |
1205 | } |
1206 | ||
1207 | static void pcpu_free_chunk(struct pcpu_chunk *chunk) | |
1208 | { | |
1209 | if (!chunk) | |
1210 | return; | |
54886c97 | 1211 | pcpu_mem_free(chunk->md_blocks); |
40064aec DZF |
1212 | pcpu_mem_free(chunk->bound_map); |
1213 | pcpu_mem_free(chunk->alloc_map); | |
1d5cfdb0 | 1214 | pcpu_mem_free(chunk); |
6081089f TH |
1215 | } |
1216 | ||
b539b87f TH |
1217 | /** |
1218 | * pcpu_chunk_populated - post-population bookkeeping | |
1219 | * @chunk: pcpu_chunk which got populated | |
1220 | * @page_start: the start page | |
1221 | * @page_end: the end page | |
40064aec | 1222 | * @for_alloc: if this is to populate for allocation |
b539b87f TH |
1223 | * |
1224 | * Pages in [@page_start,@page_end) have been populated to @chunk. Update | |
1225 | * the bookkeeping information accordingly. Must be called after each | |
1226 | * successful population. | |
40064aec DZF |
1227 | * |
1228 | * If this is @for_alloc, do not increment pcpu_nr_empty_pop_pages because it | |
1229 | * is to serve an allocation in that area. | |
b539b87f | 1230 | */ |
40064aec DZF |
1231 | static void pcpu_chunk_populated(struct pcpu_chunk *chunk, int page_start, |
1232 | int page_end, bool for_alloc) | |
b539b87f TH |
1233 | { |
1234 | int nr = page_end - page_start; | |
1235 | ||
1236 | lockdep_assert_held(&pcpu_lock); | |
1237 | ||
1238 | bitmap_set(chunk->populated, page_start, nr); | |
1239 | chunk->nr_populated += nr; | |
40064aec DZF |
1240 | |
1241 | if (!for_alloc) { | |
1242 | chunk->nr_empty_pop_pages += nr; | |
1243 | pcpu_nr_empty_pop_pages += nr; | |
1244 | } | |
b539b87f TH |
1245 | } |
1246 | ||
1247 | /** | |
1248 | * pcpu_chunk_depopulated - post-depopulation bookkeeping | |
1249 | * @chunk: pcpu_chunk which got depopulated | |
1250 | * @page_start: the start page | |
1251 | * @page_end: the end page | |
1252 | * | |
1253 | * Pages in [@page_start,@page_end) have been depopulated from @chunk. | |
1254 | * Update the bookkeeping information accordingly. Must be called after | |
1255 | * each successful depopulation. | |
1256 | */ | |
1257 | static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk, | |
1258 | int page_start, int page_end) | |
1259 | { | |
1260 | int nr = page_end - page_start; | |
1261 | ||
1262 | lockdep_assert_held(&pcpu_lock); | |
1263 | ||
1264 | bitmap_clear(chunk->populated, page_start, nr); | |
1265 | chunk->nr_populated -= nr; | |
0cecf50c | 1266 | chunk->nr_empty_pop_pages -= nr; |
b539b87f TH |
1267 | pcpu_nr_empty_pop_pages -= nr; |
1268 | } | |
1269 | ||
9f645532 TH |
1270 | /* |
1271 | * Chunk management implementation. | |
1272 | * | |
1273 | * To allow different implementations, chunk alloc/free and | |
1274 | * [de]population are implemented in a separate file which is pulled | |
1275 | * into this file and compiled together. The following functions | |
1276 | * should be implemented. | |
1277 | * | |
1278 | * pcpu_populate_chunk - populate the specified range of a chunk | |
1279 | * pcpu_depopulate_chunk - depopulate the specified range of a chunk | |
1280 | * pcpu_create_chunk - create a new chunk | |
1281 | * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop | |
1282 | * pcpu_addr_to_page - translate address to physical address | |
1283 | * pcpu_verify_alloc_info - check alloc_info is acceptable during init | |
fbf59bc9 | 1284 | */ |
72682b16 DZ |
1285 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size, |
1286 | gfp_t gfp); | |
9f645532 | 1287 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); |
72682b16 | 1288 | static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp); |
9f645532 TH |
1289 | static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); |
1290 | static struct page *pcpu_addr_to_page(void *addr); | |
1291 | static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); | |
fbf59bc9 | 1292 | |
b0c9778b TH |
1293 | #ifdef CONFIG_NEED_PER_CPU_KM |
1294 | #include "percpu-km.c" | |
1295 | #else | |
9f645532 | 1296 | #include "percpu-vm.c" |
b0c9778b | 1297 | #endif |
fbf59bc9 | 1298 | |
88999a89 TH |
1299 | /** |
1300 | * pcpu_chunk_addr_search - determine chunk containing specified address | |
1301 | * @addr: address for which the chunk needs to be determined. | |
1302 | * | |
c0ebfdc3 DZF |
1303 | * This is an internal function that handles all but static allocations. |
1304 | * Static percpu address values should never be passed into the allocator. | |
1305 | * | |
88999a89 TH |
1306 | * RETURNS: |
1307 | * The address of the found chunk. | |
1308 | */ | |
1309 | static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) | |
1310 | { | |
c0ebfdc3 | 1311 | /* is it in the dynamic region (first chunk)? */ |
560f2c23 | 1312 | if (pcpu_addr_in_chunk(pcpu_first_chunk, addr)) |
88999a89 | 1313 | return pcpu_first_chunk; |
c0ebfdc3 DZF |
1314 | |
1315 | /* is it in the reserved region? */ | |
560f2c23 | 1316 | if (pcpu_addr_in_chunk(pcpu_reserved_chunk, addr)) |
c0ebfdc3 | 1317 | return pcpu_reserved_chunk; |
88999a89 TH |
1318 | |
1319 | /* | |
1320 | * The address is relative to unit0 which might be unused and | |
1321 | * thus unmapped. Offset the address to the unit space of the | |
1322 | * current processor before looking it up in the vmalloc | |
1323 | * space. Note that any possible cpu id can be used here, so | |
1324 | * there's no need to worry about preemption or cpu hotplug. | |
1325 | */ | |
1326 | addr += pcpu_unit_offsets[raw_smp_processor_id()]; | |
9f645532 | 1327 | return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); |
88999a89 TH |
1328 | } |
1329 | ||
fbf59bc9 | 1330 | /** |
edcb4639 | 1331 | * pcpu_alloc - the percpu allocator |
cae3aeb8 | 1332 | * @size: size of area to allocate in bytes |
fbf59bc9 | 1333 | * @align: alignment of area (max PAGE_SIZE) |
edcb4639 | 1334 | * @reserved: allocate from the reserved chunk if available |
5835d96e | 1335 | * @gfp: allocation flags |
fbf59bc9 | 1336 | * |
5835d96e | 1337 | * Allocate percpu area of @size bytes aligned at @align. If @gfp doesn't |
0ea7eeec DB |
1338 | * contain %GFP_KERNEL, the allocation is atomic. If @gfp has __GFP_NOWARN |
1339 | * then no warning will be triggered on invalid or failed allocation | |
1340 | * requests. | |
fbf59bc9 TH |
1341 | * |
1342 | * RETURNS: | |
1343 | * Percpu pointer to the allocated area on success, NULL on failure. | |
1344 | */ | |
5835d96e TH |
1345 | static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, |
1346 | gfp_t gfp) | |
fbf59bc9 | 1347 | { |
0ea7eeec DB |
1348 | bool is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL; |
1349 | bool do_warn = !(gfp & __GFP_NOWARN); | |
f2badb0c | 1350 | static int warn_limit = 10; |
fbf59bc9 | 1351 | struct pcpu_chunk *chunk; |
f2badb0c | 1352 | const char *err; |
40064aec | 1353 | int slot, off, cpu, ret; |
403a91b1 | 1354 | unsigned long flags; |
f528f0b8 | 1355 | void __percpu *ptr; |
40064aec | 1356 | size_t bits, bit_align; |
fbf59bc9 | 1357 | |
723ad1d9 | 1358 | /* |
40064aec DZF |
1359 | * There is now a minimum allocation size of PCPU_MIN_ALLOC_SIZE, |
1360 | * therefore alignment must be a minimum of that many bytes. | |
1361 | * An allocation may have internal fragmentation from rounding up | |
1362 | * of up to PCPU_MIN_ALLOC_SIZE - 1 bytes. | |
723ad1d9 | 1363 | */ |
d2f3c384 DZF |
1364 | if (unlikely(align < PCPU_MIN_ALLOC_SIZE)) |
1365 | align = PCPU_MIN_ALLOC_SIZE; | |
723ad1d9 | 1366 | |
d2f3c384 | 1367 | size = ALIGN(size, PCPU_MIN_ALLOC_SIZE); |
40064aec DZF |
1368 | bits = size >> PCPU_MIN_ALLOC_SHIFT; |
1369 | bit_align = align >> PCPU_MIN_ALLOC_SHIFT; | |
2f69fa82 | 1370 | |
3ca45a46 | 1371 | if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE || |
1372 | !is_power_of_2(align))) { | |
0ea7eeec | 1373 | WARN(do_warn, "illegal size (%zu) or align (%zu) for percpu allocation\n", |
756a025f | 1374 | size, align); |
fbf59bc9 TH |
1375 | return NULL; |
1376 | } | |
1377 | ||
6710e594 TH |
1378 | if (!is_atomic) |
1379 | mutex_lock(&pcpu_alloc_mutex); | |
1380 | ||
403a91b1 | 1381 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 | 1382 | |
edcb4639 TH |
1383 | /* serve reserved allocations from the reserved chunk if available */ |
1384 | if (reserved && pcpu_reserved_chunk) { | |
1385 | chunk = pcpu_reserved_chunk; | |
833af842 | 1386 | |
40064aec DZF |
1387 | off = pcpu_find_block_fit(chunk, bits, bit_align, is_atomic); |
1388 | if (off < 0) { | |
833af842 | 1389 | err = "alloc from reserved chunk failed"; |
ccea34b5 | 1390 | goto fail_unlock; |
f2badb0c | 1391 | } |
833af842 | 1392 | |
40064aec | 1393 | off = pcpu_alloc_area(chunk, bits, bit_align, off); |
edcb4639 TH |
1394 | if (off >= 0) |
1395 | goto area_found; | |
833af842 | 1396 | |
f2badb0c | 1397 | err = "alloc from reserved chunk failed"; |
ccea34b5 | 1398 | goto fail_unlock; |
edcb4639 TH |
1399 | } |
1400 | ||
ccea34b5 | 1401 | restart: |
edcb4639 | 1402 | /* search through normal chunks */ |
fbf59bc9 TH |
1403 | for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { |
1404 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { | |
40064aec DZF |
1405 | off = pcpu_find_block_fit(chunk, bits, bit_align, |
1406 | is_atomic); | |
1407 | if (off < 0) | |
fbf59bc9 | 1408 | continue; |
ccea34b5 | 1409 | |
40064aec | 1410 | off = pcpu_alloc_area(chunk, bits, bit_align, off); |
fbf59bc9 TH |
1411 | if (off >= 0) |
1412 | goto area_found; | |
40064aec | 1413 | |
fbf59bc9 TH |
1414 | } |
1415 | } | |
1416 | ||
403a91b1 | 1417 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 | 1418 | |
b38d08f3 TH |
1419 | /* |
1420 | * No space left. Create a new chunk. We don't want multiple | |
1421 | * tasks to create chunks simultaneously. Serialize and create iff | |
1422 | * there's still no empty chunk after grabbing the mutex. | |
1423 | */ | |
11df02bf DZ |
1424 | if (is_atomic) { |
1425 | err = "atomic alloc failed, no space left"; | |
5835d96e | 1426 | goto fail; |
11df02bf | 1427 | } |
5835d96e | 1428 | |
b38d08f3 | 1429 | if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) { |
72682b16 | 1430 | chunk = pcpu_create_chunk(0); |
b38d08f3 TH |
1431 | if (!chunk) { |
1432 | err = "failed to allocate new chunk"; | |
1433 | goto fail; | |
1434 | } | |
1435 | ||
1436 | spin_lock_irqsave(&pcpu_lock, flags); | |
1437 | pcpu_chunk_relocate(chunk, -1); | |
1438 | } else { | |
1439 | spin_lock_irqsave(&pcpu_lock, flags); | |
f2badb0c | 1440 | } |
ccea34b5 | 1441 | |
ccea34b5 | 1442 | goto restart; |
fbf59bc9 TH |
1443 | |
1444 | area_found: | |
30a5b536 | 1445 | pcpu_stats_area_alloc(chunk, size); |
403a91b1 | 1446 | spin_unlock_irqrestore(&pcpu_lock, flags); |
ccea34b5 | 1447 | |
dca49645 | 1448 | /* populate if not all pages are already there */ |
5835d96e | 1449 | if (!is_atomic) { |
e04d3208 | 1450 | int page_start, page_end, rs, re; |
dca49645 | 1451 | |
e04d3208 TH |
1452 | page_start = PFN_DOWN(off); |
1453 | page_end = PFN_UP(off + size); | |
b38d08f3 | 1454 | |
91e914c5 DZF |
1455 | pcpu_for_each_unpop_region(chunk->populated, rs, re, |
1456 | page_start, page_end) { | |
e04d3208 TH |
1457 | WARN_ON(chunk->immutable); |
1458 | ||
72682b16 | 1459 | ret = pcpu_populate_chunk(chunk, rs, re, 0); |
e04d3208 TH |
1460 | |
1461 | spin_lock_irqsave(&pcpu_lock, flags); | |
1462 | if (ret) { | |
40064aec | 1463 | pcpu_free_area(chunk, off); |
e04d3208 TH |
1464 | err = "failed to populate"; |
1465 | goto fail_unlock; | |
1466 | } | |
40064aec | 1467 | pcpu_chunk_populated(chunk, rs, re, true); |
e04d3208 | 1468 | spin_unlock_irqrestore(&pcpu_lock, flags); |
dca49645 | 1469 | } |
fbf59bc9 | 1470 | |
e04d3208 TH |
1471 | mutex_unlock(&pcpu_alloc_mutex); |
1472 | } | |
ccea34b5 | 1473 | |
1a4d7607 TH |
1474 | if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW) |
1475 | pcpu_schedule_balance_work(); | |
1476 | ||
dca49645 TH |
1477 | /* clear the areas and return address relative to base address */ |
1478 | for_each_possible_cpu(cpu) | |
1479 | memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); | |
1480 | ||
f528f0b8 | 1481 | ptr = __addr_to_pcpu_ptr(chunk->base_addr + off); |
8a8c35fa | 1482 | kmemleak_alloc_percpu(ptr, size, gfp); |
df95e795 DZ |
1483 | |
1484 | trace_percpu_alloc_percpu(reserved, is_atomic, size, align, | |
1485 | chunk->base_addr, off, ptr); | |
1486 | ||
f528f0b8 | 1487 | return ptr; |
ccea34b5 TH |
1488 | |
1489 | fail_unlock: | |
403a91b1 | 1490 | spin_unlock_irqrestore(&pcpu_lock, flags); |
b38d08f3 | 1491 | fail: |
df95e795 DZ |
1492 | trace_percpu_alloc_percpu_fail(reserved, is_atomic, size, align); |
1493 | ||
0ea7eeec | 1494 | if (!is_atomic && do_warn && warn_limit) { |
870d4b12 | 1495 | pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n", |
598d8091 | 1496 | size, align, is_atomic, err); |
f2badb0c TH |
1497 | dump_stack(); |
1498 | if (!--warn_limit) | |
870d4b12 | 1499 | pr_info("limit reached, disable warning\n"); |
f2badb0c | 1500 | } |
1a4d7607 TH |
1501 | if (is_atomic) { |
1502 | /* see the flag handling in pcpu_blance_workfn() */ | |
1503 | pcpu_atomic_alloc_failed = true; | |
1504 | pcpu_schedule_balance_work(); | |
6710e594 TH |
1505 | } else { |
1506 | mutex_unlock(&pcpu_alloc_mutex); | |
1a4d7607 | 1507 | } |
ccea34b5 | 1508 | return NULL; |
fbf59bc9 | 1509 | } |
edcb4639 TH |
1510 | |
1511 | /** | |
5835d96e | 1512 | * __alloc_percpu_gfp - allocate dynamic percpu area |
edcb4639 TH |
1513 | * @size: size of area to allocate in bytes |
1514 | * @align: alignment of area (max PAGE_SIZE) | |
5835d96e | 1515 | * @gfp: allocation flags |
edcb4639 | 1516 | * |
5835d96e TH |
1517 | * Allocate zero-filled percpu area of @size bytes aligned at @align. If |
1518 | * @gfp doesn't contain %GFP_KERNEL, the allocation doesn't block and can | |
0ea7eeec DB |
1519 | * be called from any context but is a lot more likely to fail. If @gfp |
1520 | * has __GFP_NOWARN then no warning will be triggered on invalid or failed | |
1521 | * allocation requests. | |
ccea34b5 | 1522 | * |
edcb4639 TH |
1523 | * RETURNS: |
1524 | * Percpu pointer to the allocated area on success, NULL on failure. | |
1525 | */ | |
5835d96e TH |
1526 | void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) |
1527 | { | |
1528 | return pcpu_alloc(size, align, false, gfp); | |
1529 | } | |
1530 | EXPORT_SYMBOL_GPL(__alloc_percpu_gfp); | |
1531 | ||
1532 | /** | |
1533 | * __alloc_percpu - allocate dynamic percpu area | |
1534 | * @size: size of area to allocate in bytes | |
1535 | * @align: alignment of area (max PAGE_SIZE) | |
1536 | * | |
1537 | * Equivalent to __alloc_percpu_gfp(size, align, %GFP_KERNEL). | |
1538 | */ | |
43cf38eb | 1539 | void __percpu *__alloc_percpu(size_t size, size_t align) |
edcb4639 | 1540 | { |
5835d96e | 1541 | return pcpu_alloc(size, align, false, GFP_KERNEL); |
edcb4639 | 1542 | } |
fbf59bc9 TH |
1543 | EXPORT_SYMBOL_GPL(__alloc_percpu); |
1544 | ||
edcb4639 TH |
1545 | /** |
1546 | * __alloc_reserved_percpu - allocate reserved percpu area | |
1547 | * @size: size of area to allocate in bytes | |
1548 | * @align: alignment of area (max PAGE_SIZE) | |
1549 | * | |
9329ba97 TH |
1550 | * Allocate zero-filled percpu area of @size bytes aligned at @align |
1551 | * from reserved percpu area if arch has set it up; otherwise, | |
1552 | * allocation is served from the same dynamic area. Might sleep. | |
1553 | * Might trigger writeouts. | |
edcb4639 | 1554 | * |
ccea34b5 TH |
1555 | * CONTEXT: |
1556 | * Does GFP_KERNEL allocation. | |
1557 | * | |
edcb4639 TH |
1558 | * RETURNS: |
1559 | * Percpu pointer to the allocated area on success, NULL on failure. | |
1560 | */ | |
43cf38eb | 1561 | void __percpu *__alloc_reserved_percpu(size_t size, size_t align) |
edcb4639 | 1562 | { |
5835d96e | 1563 | return pcpu_alloc(size, align, true, GFP_KERNEL); |
edcb4639 TH |
1564 | } |
1565 | ||
a56dbddf | 1566 | /** |
1a4d7607 | 1567 | * pcpu_balance_workfn - manage the amount of free chunks and populated pages |
a56dbddf TH |
1568 | * @work: unused |
1569 | * | |
72682b16 DZ |
1570 | * Reclaim all fully free chunks except for the first one. This is also |
1571 | * responsible for maintaining the pool of empty populated pages. However, | |
1572 | * it is possible that this is called when physical memory is scarce causing | |
1573 | * OOM killer to be triggered. We should avoid doing so until an actual | |
1574 | * allocation causes the failure as it is possible that requests can be | |
1575 | * serviced from already backed regions. | |
a56dbddf | 1576 | */ |
fe6bd8c3 | 1577 | static void pcpu_balance_workfn(struct work_struct *work) |
fbf59bc9 | 1578 | { |
72682b16 DZ |
1579 | /* gfp flags passed to underlying allocators */ |
1580 | const gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN; | |
fe6bd8c3 TH |
1581 | LIST_HEAD(to_free); |
1582 | struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1]; | |
a56dbddf | 1583 | struct pcpu_chunk *chunk, *next; |
1a4d7607 | 1584 | int slot, nr_to_pop, ret; |
a56dbddf | 1585 | |
1a4d7607 TH |
1586 | /* |
1587 | * There's no reason to keep around multiple unused chunks and VM | |
1588 | * areas can be scarce. Destroy all free chunks except for one. | |
1589 | */ | |
ccea34b5 TH |
1590 | mutex_lock(&pcpu_alloc_mutex); |
1591 | spin_lock_irq(&pcpu_lock); | |
a56dbddf | 1592 | |
fe6bd8c3 | 1593 | list_for_each_entry_safe(chunk, next, free_head, list) { |
a56dbddf TH |
1594 | WARN_ON(chunk->immutable); |
1595 | ||
1596 | /* spare the first one */ | |
fe6bd8c3 | 1597 | if (chunk == list_first_entry(free_head, struct pcpu_chunk, list)) |
a56dbddf TH |
1598 | continue; |
1599 | ||
fe6bd8c3 | 1600 | list_move(&chunk->list, &to_free); |
a56dbddf TH |
1601 | } |
1602 | ||
ccea34b5 | 1603 | spin_unlock_irq(&pcpu_lock); |
a56dbddf | 1604 | |
fe6bd8c3 | 1605 | list_for_each_entry_safe(chunk, next, &to_free, list) { |
a93ace48 | 1606 | int rs, re; |
dca49645 | 1607 | |
91e914c5 DZF |
1608 | pcpu_for_each_pop_region(chunk->populated, rs, re, 0, |
1609 | chunk->nr_pages) { | |
a93ace48 | 1610 | pcpu_depopulate_chunk(chunk, rs, re); |
b539b87f TH |
1611 | spin_lock_irq(&pcpu_lock); |
1612 | pcpu_chunk_depopulated(chunk, rs, re); | |
1613 | spin_unlock_irq(&pcpu_lock); | |
a93ace48 | 1614 | } |
6081089f | 1615 | pcpu_destroy_chunk(chunk); |
a56dbddf | 1616 | } |
971f3918 | 1617 | |
1a4d7607 TH |
1618 | /* |
1619 | * Ensure there are certain number of free populated pages for | |
1620 | * atomic allocs. Fill up from the most packed so that atomic | |
1621 | * allocs don't increase fragmentation. If atomic allocation | |
1622 | * failed previously, always populate the maximum amount. This | |
1623 | * should prevent atomic allocs larger than PAGE_SIZE from keeping | |
1624 | * failing indefinitely; however, large atomic allocs are not | |
1625 | * something we support properly and can be highly unreliable and | |
1626 | * inefficient. | |
1627 | */ | |
1628 | retry_pop: | |
1629 | if (pcpu_atomic_alloc_failed) { | |
1630 | nr_to_pop = PCPU_EMPTY_POP_PAGES_HIGH; | |
1631 | /* best effort anyway, don't worry about synchronization */ | |
1632 | pcpu_atomic_alloc_failed = false; | |
1633 | } else { | |
1634 | nr_to_pop = clamp(PCPU_EMPTY_POP_PAGES_HIGH - | |
1635 | pcpu_nr_empty_pop_pages, | |
1636 | 0, PCPU_EMPTY_POP_PAGES_HIGH); | |
1637 | } | |
1638 | ||
1639 | for (slot = pcpu_size_to_slot(PAGE_SIZE); slot < pcpu_nr_slots; slot++) { | |
1640 | int nr_unpop = 0, rs, re; | |
1641 | ||
1642 | if (!nr_to_pop) | |
1643 | break; | |
1644 | ||
1645 | spin_lock_irq(&pcpu_lock); | |
1646 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { | |
8ab16c43 | 1647 | nr_unpop = chunk->nr_pages - chunk->nr_populated; |
1a4d7607 TH |
1648 | if (nr_unpop) |
1649 | break; | |
1650 | } | |
1651 | spin_unlock_irq(&pcpu_lock); | |
1652 | ||
1653 | if (!nr_unpop) | |
1654 | continue; | |
1655 | ||
1656 | /* @chunk can't go away while pcpu_alloc_mutex is held */ | |
91e914c5 DZF |
1657 | pcpu_for_each_unpop_region(chunk->populated, rs, re, 0, |
1658 | chunk->nr_pages) { | |
1a4d7607 TH |
1659 | int nr = min(re - rs, nr_to_pop); |
1660 | ||
72682b16 | 1661 | ret = pcpu_populate_chunk(chunk, rs, rs + nr, gfp); |
1a4d7607 TH |
1662 | if (!ret) { |
1663 | nr_to_pop -= nr; | |
1664 | spin_lock_irq(&pcpu_lock); | |
40064aec | 1665 | pcpu_chunk_populated(chunk, rs, rs + nr, false); |
1a4d7607 TH |
1666 | spin_unlock_irq(&pcpu_lock); |
1667 | } else { | |
1668 | nr_to_pop = 0; | |
1669 | } | |
1670 | ||
1671 | if (!nr_to_pop) | |
1672 | break; | |
1673 | } | |
1674 | } | |
1675 | ||
1676 | if (nr_to_pop) { | |
1677 | /* ran out of chunks to populate, create a new one and retry */ | |
72682b16 | 1678 | chunk = pcpu_create_chunk(gfp); |
1a4d7607 TH |
1679 | if (chunk) { |
1680 | spin_lock_irq(&pcpu_lock); | |
1681 | pcpu_chunk_relocate(chunk, -1); | |
1682 | spin_unlock_irq(&pcpu_lock); | |
1683 | goto retry_pop; | |
1684 | } | |
1685 | } | |
1686 | ||
971f3918 | 1687 | mutex_unlock(&pcpu_alloc_mutex); |
fbf59bc9 TH |
1688 | } |
1689 | ||
1690 | /** | |
1691 | * free_percpu - free percpu area | |
1692 | * @ptr: pointer to area to free | |
1693 | * | |
ccea34b5 TH |
1694 | * Free percpu area @ptr. |
1695 | * | |
1696 | * CONTEXT: | |
1697 | * Can be called from atomic context. | |
fbf59bc9 | 1698 | */ |
43cf38eb | 1699 | void free_percpu(void __percpu *ptr) |
fbf59bc9 | 1700 | { |
129182e5 | 1701 | void *addr; |
fbf59bc9 | 1702 | struct pcpu_chunk *chunk; |
ccea34b5 | 1703 | unsigned long flags; |
40064aec | 1704 | int off; |
fbf59bc9 TH |
1705 | |
1706 | if (!ptr) | |
1707 | return; | |
1708 | ||
f528f0b8 CM |
1709 | kmemleak_free_percpu(ptr); |
1710 | ||
129182e5 AM |
1711 | addr = __pcpu_ptr_to_addr(ptr); |
1712 | ||
ccea34b5 | 1713 | spin_lock_irqsave(&pcpu_lock, flags); |
fbf59bc9 TH |
1714 | |
1715 | chunk = pcpu_chunk_addr_search(addr); | |
bba174f5 | 1716 | off = addr - chunk->base_addr; |
fbf59bc9 | 1717 | |
40064aec | 1718 | pcpu_free_area(chunk, off); |
fbf59bc9 | 1719 | |
a56dbddf | 1720 | /* if there are more than one fully free chunks, wake up grim reaper */ |
40064aec | 1721 | if (chunk->free_bytes == pcpu_unit_size) { |
fbf59bc9 TH |
1722 | struct pcpu_chunk *pos; |
1723 | ||
a56dbddf | 1724 | list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) |
fbf59bc9 | 1725 | if (pos != chunk) { |
1a4d7607 | 1726 | pcpu_schedule_balance_work(); |
fbf59bc9 TH |
1727 | break; |
1728 | } | |
1729 | } | |
1730 | ||
df95e795 DZ |
1731 | trace_percpu_free_percpu(chunk->base_addr, off, ptr); |
1732 | ||
ccea34b5 | 1733 | spin_unlock_irqrestore(&pcpu_lock, flags); |
fbf59bc9 TH |
1734 | } |
1735 | EXPORT_SYMBOL_GPL(free_percpu); | |
1736 | ||
383776fa | 1737 | bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr) |
10fad5e4 | 1738 | { |
bbddff05 | 1739 | #ifdef CONFIG_SMP |
10fad5e4 TH |
1740 | const size_t static_size = __per_cpu_end - __per_cpu_start; |
1741 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); | |
1742 | unsigned int cpu; | |
1743 | ||
1744 | for_each_possible_cpu(cpu) { | |
1745 | void *start = per_cpu_ptr(base, cpu); | |
383776fa | 1746 | void *va = (void *)addr; |
10fad5e4 | 1747 | |
383776fa | 1748 | if (va >= start && va < start + static_size) { |
8ce371f9 | 1749 | if (can_addr) { |
383776fa | 1750 | *can_addr = (unsigned long) (va - start); |
8ce371f9 PZ |
1751 | *can_addr += (unsigned long) |
1752 | per_cpu_ptr(base, get_boot_cpu_id()); | |
1753 | } | |
10fad5e4 | 1754 | return true; |
383776fa TG |
1755 | } |
1756 | } | |
bbddff05 TH |
1757 | #endif |
1758 | /* on UP, can't distinguish from other static vars, always false */ | |
10fad5e4 TH |
1759 | return false; |
1760 | } | |
1761 | ||
383776fa TG |
1762 | /** |
1763 | * is_kernel_percpu_address - test whether address is from static percpu area | |
1764 | * @addr: address to test | |
1765 | * | |
1766 | * Test whether @addr belongs to in-kernel static percpu area. Module | |
1767 | * static percpu areas are not considered. For those, use | |
1768 | * is_module_percpu_address(). | |
1769 | * | |
1770 | * RETURNS: | |
1771 | * %true if @addr is from in-kernel static percpu area, %false otherwise. | |
1772 | */ | |
1773 | bool is_kernel_percpu_address(unsigned long addr) | |
1774 | { | |
1775 | return __is_kernel_percpu_address(addr, NULL); | |
1776 | } | |
1777 | ||
3b034b0d VG |
1778 | /** |
1779 | * per_cpu_ptr_to_phys - convert translated percpu address to physical address | |
1780 | * @addr: the address to be converted to physical address | |
1781 | * | |
1782 | * Given @addr which is dereferenceable address obtained via one of | |
1783 | * percpu access macros, this function translates it into its physical | |
1784 | * address. The caller is responsible for ensuring @addr stays valid | |
1785 | * until this function finishes. | |
1786 | * | |
67589c71 DY |
1787 | * percpu allocator has special setup for the first chunk, which currently |
1788 | * supports either embedding in linear address space or vmalloc mapping, | |
1789 | * and, from the second one, the backing allocator (currently either vm or | |
1790 | * km) provides translation. | |
1791 | * | |
bffc4375 | 1792 | * The addr can be translated simply without checking if it falls into the |
67589c71 DY |
1793 | * first chunk. But the current code reflects better how percpu allocator |
1794 | * actually works, and the verification can discover both bugs in percpu | |
1795 | * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current | |
1796 | * code. | |
1797 | * | |
3b034b0d VG |
1798 | * RETURNS: |
1799 | * The physical address for @addr. | |
1800 | */ | |
1801 | phys_addr_t per_cpu_ptr_to_phys(void *addr) | |
1802 | { | |
9983b6f0 TH |
1803 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); |
1804 | bool in_first_chunk = false; | |
a855b84c | 1805 | unsigned long first_low, first_high; |
9983b6f0 TH |
1806 | unsigned int cpu; |
1807 | ||
1808 | /* | |
a855b84c | 1809 | * The following test on unit_low/high isn't strictly |
9983b6f0 TH |
1810 | * necessary but will speed up lookups of addresses which |
1811 | * aren't in the first chunk. | |
c0ebfdc3 DZF |
1812 | * |
1813 | * The address check is against full chunk sizes. pcpu_base_addr | |
1814 | * points to the beginning of the first chunk including the | |
1815 | * static region. Assumes good intent as the first chunk may | |
1816 | * not be full (ie. < pcpu_unit_pages in size). | |
9983b6f0 | 1817 | */ |
c0ebfdc3 DZF |
1818 | first_low = (unsigned long)pcpu_base_addr + |
1819 | pcpu_unit_page_offset(pcpu_low_unit_cpu, 0); | |
1820 | first_high = (unsigned long)pcpu_base_addr + | |
1821 | pcpu_unit_page_offset(pcpu_high_unit_cpu, pcpu_unit_pages); | |
a855b84c TH |
1822 | if ((unsigned long)addr >= first_low && |
1823 | (unsigned long)addr < first_high) { | |
9983b6f0 TH |
1824 | for_each_possible_cpu(cpu) { |
1825 | void *start = per_cpu_ptr(base, cpu); | |
1826 | ||
1827 | if (addr >= start && addr < start + pcpu_unit_size) { | |
1828 | in_first_chunk = true; | |
1829 | break; | |
1830 | } | |
1831 | } | |
1832 | } | |
1833 | ||
1834 | if (in_first_chunk) { | |
eac522ef | 1835 | if (!is_vmalloc_addr(addr)) |
020ec653 TH |
1836 | return __pa(addr); |
1837 | else | |
9f57bd4d ES |
1838 | return page_to_phys(vmalloc_to_page(addr)) + |
1839 | offset_in_page(addr); | |
020ec653 | 1840 | } else |
9f57bd4d ES |
1841 | return page_to_phys(pcpu_addr_to_page(addr)) + |
1842 | offset_in_page(addr); | |
3b034b0d VG |
1843 | } |
1844 | ||
fbf59bc9 | 1845 | /** |
fd1e8a1f TH |
1846 | * pcpu_alloc_alloc_info - allocate percpu allocation info |
1847 | * @nr_groups: the number of groups | |
1848 | * @nr_units: the number of units | |
1849 | * | |
1850 | * Allocate ai which is large enough for @nr_groups groups containing | |
1851 | * @nr_units units. The returned ai's groups[0].cpu_map points to the | |
1852 | * cpu_map array which is long enough for @nr_units and filled with | |
1853 | * NR_CPUS. It's the caller's responsibility to initialize cpu_map | |
1854 | * pointer of other groups. | |
1855 | * | |
1856 | * RETURNS: | |
1857 | * Pointer to the allocated pcpu_alloc_info on success, NULL on | |
1858 | * failure. | |
1859 | */ | |
1860 | struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, | |
1861 | int nr_units) | |
1862 | { | |
1863 | struct pcpu_alloc_info *ai; | |
1864 | size_t base_size, ai_size; | |
1865 | void *ptr; | |
1866 | int unit; | |
1867 | ||
1868 | base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), | |
1869 | __alignof__(ai->groups[0].cpu_map[0])); | |
1870 | ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); | |
1871 | ||
999c17e3 | 1872 | ptr = memblock_virt_alloc_nopanic(PFN_ALIGN(ai_size), 0); |
fd1e8a1f TH |
1873 | if (!ptr) |
1874 | return NULL; | |
1875 | ai = ptr; | |
1876 | ptr += base_size; | |
1877 | ||
1878 | ai->groups[0].cpu_map = ptr; | |
1879 | ||
1880 | for (unit = 0; unit < nr_units; unit++) | |
1881 | ai->groups[0].cpu_map[unit] = NR_CPUS; | |
1882 | ||
1883 | ai->nr_groups = nr_groups; | |
1884 | ai->__ai_size = PFN_ALIGN(ai_size); | |
1885 | ||
1886 | return ai; | |
1887 | } | |
1888 | ||
1889 | /** | |
1890 | * pcpu_free_alloc_info - free percpu allocation info | |
1891 | * @ai: pcpu_alloc_info to free | |
1892 | * | |
1893 | * Free @ai which was allocated by pcpu_alloc_alloc_info(). | |
1894 | */ | |
1895 | void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) | |
1896 | { | |
999c17e3 | 1897 | memblock_free_early(__pa(ai), ai->__ai_size); |
fd1e8a1f TH |
1898 | } |
1899 | ||
fd1e8a1f TH |
1900 | /** |
1901 | * pcpu_dump_alloc_info - print out information about pcpu_alloc_info | |
1902 | * @lvl: loglevel | |
1903 | * @ai: allocation info to dump | |
1904 | * | |
1905 | * Print out information about @ai using loglevel @lvl. | |
1906 | */ | |
1907 | static void pcpu_dump_alloc_info(const char *lvl, | |
1908 | const struct pcpu_alloc_info *ai) | |
033e48fb | 1909 | { |
fd1e8a1f | 1910 | int group_width = 1, cpu_width = 1, width; |
033e48fb | 1911 | char empty_str[] = "--------"; |
fd1e8a1f TH |
1912 | int alloc = 0, alloc_end = 0; |
1913 | int group, v; | |
1914 | int upa, apl; /* units per alloc, allocs per line */ | |
1915 | ||
1916 | v = ai->nr_groups; | |
1917 | while (v /= 10) | |
1918 | group_width++; | |
033e48fb | 1919 | |
fd1e8a1f | 1920 | v = num_possible_cpus(); |
033e48fb | 1921 | while (v /= 10) |
fd1e8a1f TH |
1922 | cpu_width++; |
1923 | empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; | |
033e48fb | 1924 | |
fd1e8a1f TH |
1925 | upa = ai->alloc_size / ai->unit_size; |
1926 | width = upa * (cpu_width + 1) + group_width + 3; | |
1927 | apl = rounddown_pow_of_two(max(60 / width, 1)); | |
033e48fb | 1928 | |
fd1e8a1f TH |
1929 | printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", |
1930 | lvl, ai->static_size, ai->reserved_size, ai->dyn_size, | |
1931 | ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); | |
033e48fb | 1932 | |
fd1e8a1f TH |
1933 | for (group = 0; group < ai->nr_groups; group++) { |
1934 | const struct pcpu_group_info *gi = &ai->groups[group]; | |
1935 | int unit = 0, unit_end = 0; | |
1936 | ||
1937 | BUG_ON(gi->nr_units % upa); | |
1938 | for (alloc_end += gi->nr_units / upa; | |
1939 | alloc < alloc_end; alloc++) { | |
1940 | if (!(alloc % apl)) { | |
1170532b | 1941 | pr_cont("\n"); |
fd1e8a1f TH |
1942 | printk("%spcpu-alloc: ", lvl); |
1943 | } | |
1170532b | 1944 | pr_cont("[%0*d] ", group_width, group); |
fd1e8a1f TH |
1945 | |
1946 | for (unit_end += upa; unit < unit_end; unit++) | |
1947 | if (gi->cpu_map[unit] != NR_CPUS) | |
1170532b JP |
1948 | pr_cont("%0*d ", |
1949 | cpu_width, gi->cpu_map[unit]); | |
fd1e8a1f | 1950 | else |
1170532b | 1951 | pr_cont("%s ", empty_str); |
033e48fb | 1952 | } |
033e48fb | 1953 | } |
1170532b | 1954 | pr_cont("\n"); |
033e48fb | 1955 | } |
033e48fb | 1956 | |
fbf59bc9 | 1957 | /** |
8d408b4b | 1958 | * pcpu_setup_first_chunk - initialize the first percpu chunk |
fd1e8a1f | 1959 | * @ai: pcpu_alloc_info describing how to percpu area is shaped |
38a6be52 | 1960 | * @base_addr: mapped address |
8d408b4b TH |
1961 | * |
1962 | * Initialize the first percpu chunk which contains the kernel static | |
1963 | * perpcu area. This function is to be called from arch percpu area | |
38a6be52 | 1964 | * setup path. |
8d408b4b | 1965 | * |
fd1e8a1f TH |
1966 | * @ai contains all information necessary to initialize the first |
1967 | * chunk and prime the dynamic percpu allocator. | |
1968 | * | |
1969 | * @ai->static_size is the size of static percpu area. | |
1970 | * | |
1971 | * @ai->reserved_size, if non-zero, specifies the amount of bytes to | |
edcb4639 TH |
1972 | * reserve after the static area in the first chunk. This reserves |
1973 | * the first chunk such that it's available only through reserved | |
1974 | * percpu allocation. This is primarily used to serve module percpu | |
1975 | * static areas on architectures where the addressing model has | |
1976 | * limited offset range for symbol relocations to guarantee module | |
1977 | * percpu symbols fall inside the relocatable range. | |
1978 | * | |
fd1e8a1f TH |
1979 | * @ai->dyn_size determines the number of bytes available for dynamic |
1980 | * allocation in the first chunk. The area between @ai->static_size + | |
1981 | * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. | |
6074d5b0 | 1982 | * |
fd1e8a1f TH |
1983 | * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE |
1984 | * and equal to or larger than @ai->static_size + @ai->reserved_size + | |
1985 | * @ai->dyn_size. | |
8d408b4b | 1986 | * |
fd1e8a1f TH |
1987 | * @ai->atom_size is the allocation atom size and used as alignment |
1988 | * for vm areas. | |
8d408b4b | 1989 | * |
fd1e8a1f TH |
1990 | * @ai->alloc_size is the allocation size and always multiple of |
1991 | * @ai->atom_size. This is larger than @ai->atom_size if | |
1992 | * @ai->unit_size is larger than @ai->atom_size. | |
1993 | * | |
1994 | * @ai->nr_groups and @ai->groups describe virtual memory layout of | |
1995 | * percpu areas. Units which should be colocated are put into the | |
1996 | * same group. Dynamic VM areas will be allocated according to these | |
1997 | * groupings. If @ai->nr_groups is zero, a single group containing | |
1998 | * all units is assumed. | |
8d408b4b | 1999 | * |
38a6be52 TH |
2000 | * The caller should have mapped the first chunk at @base_addr and |
2001 | * copied static data to each unit. | |
fbf59bc9 | 2002 | * |
c0ebfdc3 DZF |
2003 | * The first chunk will always contain a static and a dynamic region. |
2004 | * However, the static region is not managed by any chunk. If the first | |
2005 | * chunk also contains a reserved region, it is served by two chunks - | |
2006 | * one for the reserved region and one for the dynamic region. They | |
2007 | * share the same vm, but use offset regions in the area allocation map. | |
2008 | * The chunk serving the dynamic region is circulated in the chunk slots | |
2009 | * and available for dynamic allocation like any other chunk. | |
edcb4639 | 2010 | * |
fbf59bc9 | 2011 | * RETURNS: |
fb435d52 | 2012 | * 0 on success, -errno on failure. |
fbf59bc9 | 2013 | */ |
fb435d52 TH |
2014 | int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, |
2015 | void *base_addr) | |
fbf59bc9 | 2016 | { |
b9c39442 | 2017 | size_t size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; |
d2f3c384 | 2018 | size_t static_size, dyn_size; |
0c4169c3 | 2019 | struct pcpu_chunk *chunk; |
6563297c TH |
2020 | unsigned long *group_offsets; |
2021 | size_t *group_sizes; | |
fb435d52 | 2022 | unsigned long *unit_off; |
fbf59bc9 | 2023 | unsigned int cpu; |
fd1e8a1f TH |
2024 | int *unit_map; |
2025 | int group, unit, i; | |
c0ebfdc3 DZF |
2026 | int map_size; |
2027 | unsigned long tmp_addr; | |
fbf59bc9 | 2028 | |
635b75fc TH |
2029 | #define PCPU_SETUP_BUG_ON(cond) do { \ |
2030 | if (unlikely(cond)) { \ | |
870d4b12 JP |
2031 | pr_emerg("failed to initialize, %s\n", #cond); \ |
2032 | pr_emerg("cpu_possible_mask=%*pb\n", \ | |
807de073 | 2033 | cpumask_pr_args(cpu_possible_mask)); \ |
635b75fc TH |
2034 | pcpu_dump_alloc_info(KERN_EMERG, ai); \ |
2035 | BUG(); \ | |
2036 | } \ | |
2037 | } while (0) | |
2038 | ||
2f39e637 | 2039 | /* sanity checks */ |
635b75fc | 2040 | PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); |
bbddff05 | 2041 | #ifdef CONFIG_SMP |
635b75fc | 2042 | PCPU_SETUP_BUG_ON(!ai->static_size); |
f09f1243 | 2043 | PCPU_SETUP_BUG_ON(offset_in_page(__per_cpu_start)); |
bbddff05 | 2044 | #endif |
635b75fc | 2045 | PCPU_SETUP_BUG_ON(!base_addr); |
f09f1243 | 2046 | PCPU_SETUP_BUG_ON(offset_in_page(base_addr)); |
635b75fc | 2047 | PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); |
f09f1243 | 2048 | PCPU_SETUP_BUG_ON(offset_in_page(ai->unit_size)); |
635b75fc | 2049 | PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); |
ca460b3c | 2050 | PCPU_SETUP_BUG_ON(!IS_ALIGNED(ai->unit_size, PCPU_BITMAP_BLOCK_SIZE)); |
099a19d9 | 2051 | PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE); |
fb29a2cc | 2052 | PCPU_SETUP_BUG_ON(!ai->dyn_size); |
d2f3c384 | 2053 | PCPU_SETUP_BUG_ON(!IS_ALIGNED(ai->reserved_size, PCPU_MIN_ALLOC_SIZE)); |
ca460b3c DZF |
2054 | PCPU_SETUP_BUG_ON(!(IS_ALIGNED(PCPU_BITMAP_BLOCK_SIZE, PAGE_SIZE) || |
2055 | IS_ALIGNED(PAGE_SIZE, PCPU_BITMAP_BLOCK_SIZE))); | |
9f645532 | 2056 | PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); |
8d408b4b | 2057 | |
6563297c | 2058 | /* process group information and build config tables accordingly */ |
999c17e3 SS |
2059 | group_offsets = memblock_virt_alloc(ai->nr_groups * |
2060 | sizeof(group_offsets[0]), 0); | |
2061 | group_sizes = memblock_virt_alloc(ai->nr_groups * | |
2062 | sizeof(group_sizes[0]), 0); | |
2063 | unit_map = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_map[0]), 0); | |
2064 | unit_off = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_off[0]), 0); | |
2f39e637 | 2065 | |
fd1e8a1f | 2066 | for (cpu = 0; cpu < nr_cpu_ids; cpu++) |
ffe0d5a5 | 2067 | unit_map[cpu] = UINT_MAX; |
a855b84c TH |
2068 | |
2069 | pcpu_low_unit_cpu = NR_CPUS; | |
2070 | pcpu_high_unit_cpu = NR_CPUS; | |
2f39e637 | 2071 | |
fd1e8a1f TH |
2072 | for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { |
2073 | const struct pcpu_group_info *gi = &ai->groups[group]; | |
2f39e637 | 2074 | |
6563297c TH |
2075 | group_offsets[group] = gi->base_offset; |
2076 | group_sizes[group] = gi->nr_units * ai->unit_size; | |
2077 | ||
fd1e8a1f TH |
2078 | for (i = 0; i < gi->nr_units; i++) { |
2079 | cpu = gi->cpu_map[i]; | |
2080 | if (cpu == NR_CPUS) | |
2081 | continue; | |
8d408b4b | 2082 | |
9f295664 | 2083 | PCPU_SETUP_BUG_ON(cpu >= nr_cpu_ids); |
635b75fc TH |
2084 | PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); |
2085 | PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); | |
fbf59bc9 | 2086 | |
fd1e8a1f | 2087 | unit_map[cpu] = unit + i; |
fb435d52 TH |
2088 | unit_off[cpu] = gi->base_offset + i * ai->unit_size; |
2089 | ||
a855b84c TH |
2090 | /* determine low/high unit_cpu */ |
2091 | if (pcpu_low_unit_cpu == NR_CPUS || | |
2092 | unit_off[cpu] < unit_off[pcpu_low_unit_cpu]) | |
2093 | pcpu_low_unit_cpu = cpu; | |
2094 | if (pcpu_high_unit_cpu == NR_CPUS || | |
2095 | unit_off[cpu] > unit_off[pcpu_high_unit_cpu]) | |
2096 | pcpu_high_unit_cpu = cpu; | |
fd1e8a1f | 2097 | } |
2f39e637 | 2098 | } |
fd1e8a1f TH |
2099 | pcpu_nr_units = unit; |
2100 | ||
2101 | for_each_possible_cpu(cpu) | |
635b75fc TH |
2102 | PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); |
2103 | ||
2104 | /* we're done parsing the input, undefine BUG macro and dump config */ | |
2105 | #undef PCPU_SETUP_BUG_ON | |
bcbea798 | 2106 | pcpu_dump_alloc_info(KERN_DEBUG, ai); |
fd1e8a1f | 2107 | |
6563297c TH |
2108 | pcpu_nr_groups = ai->nr_groups; |
2109 | pcpu_group_offsets = group_offsets; | |
2110 | pcpu_group_sizes = group_sizes; | |
fd1e8a1f | 2111 | pcpu_unit_map = unit_map; |
fb435d52 | 2112 | pcpu_unit_offsets = unit_off; |
2f39e637 TH |
2113 | |
2114 | /* determine basic parameters */ | |
fd1e8a1f | 2115 | pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; |
d9b55eeb | 2116 | pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; |
6563297c | 2117 | pcpu_atom_size = ai->atom_size; |
ce3141a2 TH |
2118 | pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + |
2119 | BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); | |
cafe8816 | 2120 | |
30a5b536 DZ |
2121 | pcpu_stats_save_ai(ai); |
2122 | ||
d9b55eeb TH |
2123 | /* |
2124 | * Allocate chunk slots. The additional last slot is for | |
2125 | * empty chunks. | |
2126 | */ | |
2127 | pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; | |
999c17e3 SS |
2128 | pcpu_slot = memblock_virt_alloc( |
2129 | pcpu_nr_slots * sizeof(pcpu_slot[0]), 0); | |
fbf59bc9 TH |
2130 | for (i = 0; i < pcpu_nr_slots; i++) |
2131 | INIT_LIST_HEAD(&pcpu_slot[i]); | |
2132 | ||
d2f3c384 DZF |
2133 | /* |
2134 | * The end of the static region needs to be aligned with the | |
2135 | * minimum allocation size as this offsets the reserved and | |
2136 | * dynamic region. The first chunk ends page aligned by | |
2137 | * expanding the dynamic region, therefore the dynamic region | |
2138 | * can be shrunk to compensate while still staying above the | |
2139 | * configured sizes. | |
2140 | */ | |
2141 | static_size = ALIGN(ai->static_size, PCPU_MIN_ALLOC_SIZE); | |
2142 | dyn_size = ai->dyn_size - (static_size - ai->static_size); | |
2143 | ||
edcb4639 | 2144 | /* |
c0ebfdc3 DZF |
2145 | * Initialize first chunk. |
2146 | * If the reserved_size is non-zero, this initializes the reserved | |
2147 | * chunk. If the reserved_size is zero, the reserved chunk is NULL | |
2148 | * and the dynamic region is initialized here. The first chunk, | |
2149 | * pcpu_first_chunk, will always point to the chunk that serves | |
2150 | * the dynamic region. | |
edcb4639 | 2151 | */ |
d2f3c384 DZF |
2152 | tmp_addr = (unsigned long)base_addr + static_size; |
2153 | map_size = ai->reserved_size ?: dyn_size; | |
40064aec | 2154 | chunk = pcpu_alloc_first_chunk(tmp_addr, map_size); |
61ace7fa | 2155 | |
edcb4639 | 2156 | /* init dynamic chunk if necessary */ |
b9c39442 | 2157 | if (ai->reserved_size) { |
0c4169c3 | 2158 | pcpu_reserved_chunk = chunk; |
b9c39442 | 2159 | |
d2f3c384 | 2160 | tmp_addr = (unsigned long)base_addr + static_size + |
c0ebfdc3 | 2161 | ai->reserved_size; |
d2f3c384 | 2162 | map_size = dyn_size; |
40064aec | 2163 | chunk = pcpu_alloc_first_chunk(tmp_addr, map_size); |
edcb4639 TH |
2164 | } |
2165 | ||
2441d15c | 2166 | /* link the first chunk in */ |
0c4169c3 | 2167 | pcpu_first_chunk = chunk; |
0cecf50c | 2168 | pcpu_nr_empty_pop_pages = pcpu_first_chunk->nr_empty_pop_pages; |
ae9e6bc9 | 2169 | pcpu_chunk_relocate(pcpu_first_chunk, -1); |
fbf59bc9 | 2170 | |
30a5b536 | 2171 | pcpu_stats_chunk_alloc(); |
df95e795 | 2172 | trace_percpu_create_chunk(base_addr); |
30a5b536 | 2173 | |
fbf59bc9 | 2174 | /* we're done */ |
bba174f5 | 2175 | pcpu_base_addr = base_addr; |
fb435d52 | 2176 | return 0; |
fbf59bc9 | 2177 | } |
66c3a757 | 2178 | |
bbddff05 TH |
2179 | #ifdef CONFIG_SMP |
2180 | ||
17f3609c | 2181 | const char * const pcpu_fc_names[PCPU_FC_NR] __initconst = { |
f58dc01b TH |
2182 | [PCPU_FC_AUTO] = "auto", |
2183 | [PCPU_FC_EMBED] = "embed", | |
2184 | [PCPU_FC_PAGE] = "page", | |
f58dc01b | 2185 | }; |
66c3a757 | 2186 | |
f58dc01b | 2187 | enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; |
66c3a757 | 2188 | |
f58dc01b TH |
2189 | static int __init percpu_alloc_setup(char *str) |
2190 | { | |
5479c78a CG |
2191 | if (!str) |
2192 | return -EINVAL; | |
2193 | ||
f58dc01b TH |
2194 | if (0) |
2195 | /* nada */; | |
2196 | #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK | |
2197 | else if (!strcmp(str, "embed")) | |
2198 | pcpu_chosen_fc = PCPU_FC_EMBED; | |
2199 | #endif | |
2200 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK | |
2201 | else if (!strcmp(str, "page")) | |
2202 | pcpu_chosen_fc = PCPU_FC_PAGE; | |
f58dc01b TH |
2203 | #endif |
2204 | else | |
870d4b12 | 2205 | pr_warn("unknown allocator %s specified\n", str); |
66c3a757 | 2206 | |
f58dc01b | 2207 | return 0; |
66c3a757 | 2208 | } |
f58dc01b | 2209 | early_param("percpu_alloc", percpu_alloc_setup); |
66c3a757 | 2210 | |
3c9a024f TH |
2211 | /* |
2212 | * pcpu_embed_first_chunk() is used by the generic percpu setup. | |
2213 | * Build it if needed by the arch config or the generic setup is going | |
2214 | * to be used. | |
2215 | */ | |
08fc4580 TH |
2216 | #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ |
2217 | !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) | |
3c9a024f TH |
2218 | #define BUILD_EMBED_FIRST_CHUNK |
2219 | #endif | |
2220 | ||
2221 | /* build pcpu_page_first_chunk() iff needed by the arch config */ | |
2222 | #if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) | |
2223 | #define BUILD_PAGE_FIRST_CHUNK | |
2224 | #endif | |
2225 | ||
2226 | /* pcpu_build_alloc_info() is used by both embed and page first chunk */ | |
2227 | #if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK) | |
2228 | /** | |
2229 | * pcpu_build_alloc_info - build alloc_info considering distances between CPUs | |
2230 | * @reserved_size: the size of reserved percpu area in bytes | |
2231 | * @dyn_size: minimum free size for dynamic allocation in bytes | |
2232 | * @atom_size: allocation atom size | |
2233 | * @cpu_distance_fn: callback to determine distance between cpus, optional | |
2234 | * | |
2235 | * This function determines grouping of units, their mappings to cpus | |
2236 | * and other parameters considering needed percpu size, allocation | |
2237 | * atom size and distances between CPUs. | |
2238 | * | |
bffc4375 | 2239 | * Groups are always multiples of atom size and CPUs which are of |
3c9a024f TH |
2240 | * LOCAL_DISTANCE both ways are grouped together and share space for |
2241 | * units in the same group. The returned configuration is guaranteed | |
2242 | * to have CPUs on different nodes on different groups and >=75% usage | |
2243 | * of allocated virtual address space. | |
2244 | * | |
2245 | * RETURNS: | |
2246 | * On success, pointer to the new allocation_info is returned. On | |
2247 | * failure, ERR_PTR value is returned. | |
2248 | */ | |
2249 | static struct pcpu_alloc_info * __init pcpu_build_alloc_info( | |
2250 | size_t reserved_size, size_t dyn_size, | |
2251 | size_t atom_size, | |
2252 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn) | |
2253 | { | |
2254 | static int group_map[NR_CPUS] __initdata; | |
2255 | static int group_cnt[NR_CPUS] __initdata; | |
2256 | const size_t static_size = __per_cpu_end - __per_cpu_start; | |
2257 | int nr_groups = 1, nr_units = 0; | |
2258 | size_t size_sum, min_unit_size, alloc_size; | |
2259 | int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ | |
2260 | int last_allocs, group, unit; | |
2261 | unsigned int cpu, tcpu; | |
2262 | struct pcpu_alloc_info *ai; | |
2263 | unsigned int *cpu_map; | |
2264 | ||
2265 | /* this function may be called multiple times */ | |
2266 | memset(group_map, 0, sizeof(group_map)); | |
2267 | memset(group_cnt, 0, sizeof(group_cnt)); | |
2268 | ||
2269 | /* calculate size_sum and ensure dyn_size is enough for early alloc */ | |
2270 | size_sum = PFN_ALIGN(static_size + reserved_size + | |
2271 | max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE)); | |
2272 | dyn_size = size_sum - static_size - reserved_size; | |
2273 | ||
2274 | /* | |
2275 | * Determine min_unit_size, alloc_size and max_upa such that | |
2276 | * alloc_size is multiple of atom_size and is the smallest | |
25985edc | 2277 | * which can accommodate 4k aligned segments which are equal to |
3c9a024f TH |
2278 | * or larger than min_unit_size. |
2279 | */ | |
2280 | min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); | |
2281 | ||
9c015162 | 2282 | /* determine the maximum # of units that can fit in an allocation */ |
3c9a024f TH |
2283 | alloc_size = roundup(min_unit_size, atom_size); |
2284 | upa = alloc_size / min_unit_size; | |
f09f1243 | 2285 | while (alloc_size % upa || (offset_in_page(alloc_size / upa))) |
3c9a024f TH |
2286 | upa--; |
2287 | max_upa = upa; | |
2288 | ||
2289 | /* group cpus according to their proximity */ | |
2290 | for_each_possible_cpu(cpu) { | |
2291 | group = 0; | |
2292 | next_group: | |
2293 | for_each_possible_cpu(tcpu) { | |
2294 | if (cpu == tcpu) | |
2295 | break; | |
2296 | if (group_map[tcpu] == group && cpu_distance_fn && | |
2297 | (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || | |
2298 | cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { | |
2299 | group++; | |
2300 | nr_groups = max(nr_groups, group + 1); | |
2301 | goto next_group; | |
2302 | } | |
2303 | } | |
2304 | group_map[cpu] = group; | |
2305 | group_cnt[group]++; | |
2306 | } | |
2307 | ||
2308 | /* | |
9c015162 DZF |
2309 | * Wasted space is caused by a ratio imbalance of upa to group_cnt. |
2310 | * Expand the unit_size until we use >= 75% of the units allocated. | |
2311 | * Related to atom_size, which could be much larger than the unit_size. | |
3c9a024f TH |
2312 | */ |
2313 | last_allocs = INT_MAX; | |
2314 | for (upa = max_upa; upa; upa--) { | |
2315 | int allocs = 0, wasted = 0; | |
2316 | ||
f09f1243 | 2317 | if (alloc_size % upa || (offset_in_page(alloc_size / upa))) |
3c9a024f TH |
2318 | continue; |
2319 | ||
2320 | for (group = 0; group < nr_groups; group++) { | |
2321 | int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); | |
2322 | allocs += this_allocs; | |
2323 | wasted += this_allocs * upa - group_cnt[group]; | |
2324 | } | |
2325 | ||
2326 | /* | |
2327 | * Don't accept if wastage is over 1/3. The | |
2328 | * greater-than comparison ensures upa==1 always | |
2329 | * passes the following check. | |
2330 | */ | |
2331 | if (wasted > num_possible_cpus() / 3) | |
2332 | continue; | |
2333 | ||
2334 | /* and then don't consume more memory */ | |
2335 | if (allocs > last_allocs) | |
2336 | break; | |
2337 | last_allocs = allocs; | |
2338 | best_upa = upa; | |
2339 | } | |
2340 | upa = best_upa; | |
2341 | ||
2342 | /* allocate and fill alloc_info */ | |
2343 | for (group = 0; group < nr_groups; group++) | |
2344 | nr_units += roundup(group_cnt[group], upa); | |
2345 | ||
2346 | ai = pcpu_alloc_alloc_info(nr_groups, nr_units); | |
2347 | if (!ai) | |
2348 | return ERR_PTR(-ENOMEM); | |
2349 | cpu_map = ai->groups[0].cpu_map; | |
2350 | ||
2351 | for (group = 0; group < nr_groups; group++) { | |
2352 | ai->groups[group].cpu_map = cpu_map; | |
2353 | cpu_map += roundup(group_cnt[group], upa); | |
2354 | } | |
2355 | ||
2356 | ai->static_size = static_size; | |
2357 | ai->reserved_size = reserved_size; | |
2358 | ai->dyn_size = dyn_size; | |
2359 | ai->unit_size = alloc_size / upa; | |
2360 | ai->atom_size = atom_size; | |
2361 | ai->alloc_size = alloc_size; | |
2362 | ||
2363 | for (group = 0, unit = 0; group_cnt[group]; group++) { | |
2364 | struct pcpu_group_info *gi = &ai->groups[group]; | |
2365 | ||
2366 | /* | |
2367 | * Initialize base_offset as if all groups are located | |
2368 | * back-to-back. The caller should update this to | |
2369 | * reflect actual allocation. | |
2370 | */ | |
2371 | gi->base_offset = unit * ai->unit_size; | |
2372 | ||
2373 | for_each_possible_cpu(cpu) | |
2374 | if (group_map[cpu] == group) | |
2375 | gi->cpu_map[gi->nr_units++] = cpu; | |
2376 | gi->nr_units = roundup(gi->nr_units, upa); | |
2377 | unit += gi->nr_units; | |
2378 | } | |
2379 | BUG_ON(unit != nr_units); | |
2380 | ||
2381 | return ai; | |
2382 | } | |
2383 | #endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */ | |
2384 | ||
2385 | #if defined(BUILD_EMBED_FIRST_CHUNK) | |
66c3a757 TH |
2386 | /** |
2387 | * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem | |
66c3a757 | 2388 | * @reserved_size: the size of reserved percpu area in bytes |
4ba6ce25 | 2389 | * @dyn_size: minimum free size for dynamic allocation in bytes |
c8826dd5 TH |
2390 | * @atom_size: allocation atom size |
2391 | * @cpu_distance_fn: callback to determine distance between cpus, optional | |
2392 | * @alloc_fn: function to allocate percpu page | |
25985edc | 2393 | * @free_fn: function to free percpu page |
66c3a757 TH |
2394 | * |
2395 | * This is a helper to ease setting up embedded first percpu chunk and | |
2396 | * can be called where pcpu_setup_first_chunk() is expected. | |
2397 | * | |
2398 | * If this function is used to setup the first chunk, it is allocated | |
c8826dd5 TH |
2399 | * by calling @alloc_fn and used as-is without being mapped into |
2400 | * vmalloc area. Allocations are always whole multiples of @atom_size | |
2401 | * aligned to @atom_size. | |
2402 | * | |
2403 | * This enables the first chunk to piggy back on the linear physical | |
2404 | * mapping which often uses larger page size. Please note that this | |
2405 | * can result in very sparse cpu->unit mapping on NUMA machines thus | |
2406 | * requiring large vmalloc address space. Don't use this allocator if | |
2407 | * vmalloc space is not orders of magnitude larger than distances | |
2408 | * between node memory addresses (ie. 32bit NUMA machines). | |
66c3a757 | 2409 | * |
4ba6ce25 | 2410 | * @dyn_size specifies the minimum dynamic area size. |
66c3a757 TH |
2411 | * |
2412 | * If the needed size is smaller than the minimum or specified unit | |
c8826dd5 | 2413 | * size, the leftover is returned using @free_fn. |
66c3a757 TH |
2414 | * |
2415 | * RETURNS: | |
fb435d52 | 2416 | * 0 on success, -errno on failure. |
66c3a757 | 2417 | */ |
4ba6ce25 | 2418 | int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, |
c8826dd5 TH |
2419 | size_t atom_size, |
2420 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn, | |
2421 | pcpu_fc_alloc_fn_t alloc_fn, | |
2422 | pcpu_fc_free_fn_t free_fn) | |
66c3a757 | 2423 | { |
c8826dd5 TH |
2424 | void *base = (void *)ULONG_MAX; |
2425 | void **areas = NULL; | |
fd1e8a1f | 2426 | struct pcpu_alloc_info *ai; |
93c76b6b | 2427 | size_t size_sum, areas_size; |
2428 | unsigned long max_distance; | |
9b739662 | 2429 | int group, i, highest_group, rc; |
66c3a757 | 2430 | |
c8826dd5 TH |
2431 | ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, |
2432 | cpu_distance_fn); | |
fd1e8a1f TH |
2433 | if (IS_ERR(ai)) |
2434 | return PTR_ERR(ai); | |
66c3a757 | 2435 | |
fd1e8a1f | 2436 | size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; |
c8826dd5 | 2437 | areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); |
fa8a7094 | 2438 | |
999c17e3 | 2439 | areas = memblock_virt_alloc_nopanic(areas_size, 0); |
c8826dd5 | 2440 | if (!areas) { |
fb435d52 | 2441 | rc = -ENOMEM; |
c8826dd5 | 2442 | goto out_free; |
fa8a7094 | 2443 | } |
66c3a757 | 2444 | |
9b739662 | 2445 | /* allocate, copy and determine base address & max_distance */ |
2446 | highest_group = 0; | |
c8826dd5 TH |
2447 | for (group = 0; group < ai->nr_groups; group++) { |
2448 | struct pcpu_group_info *gi = &ai->groups[group]; | |
2449 | unsigned int cpu = NR_CPUS; | |
2450 | void *ptr; | |
2451 | ||
2452 | for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) | |
2453 | cpu = gi->cpu_map[i]; | |
2454 | BUG_ON(cpu == NR_CPUS); | |
2455 | ||
2456 | /* allocate space for the whole group */ | |
2457 | ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); | |
2458 | if (!ptr) { | |
2459 | rc = -ENOMEM; | |
2460 | goto out_free_areas; | |
2461 | } | |
f528f0b8 CM |
2462 | /* kmemleak tracks the percpu allocations separately */ |
2463 | kmemleak_free(ptr); | |
c8826dd5 | 2464 | areas[group] = ptr; |
fd1e8a1f | 2465 | |
c8826dd5 | 2466 | base = min(ptr, base); |
9b739662 | 2467 | if (ptr > areas[highest_group]) |
2468 | highest_group = group; | |
2469 | } | |
2470 | max_distance = areas[highest_group] - base; | |
2471 | max_distance += ai->unit_size * ai->groups[highest_group].nr_units; | |
2472 | ||
2473 | /* warn if maximum distance is further than 75% of vmalloc space */ | |
2474 | if (max_distance > VMALLOC_TOTAL * 3 / 4) { | |
2475 | pr_warn("max_distance=0x%lx too large for vmalloc space 0x%lx\n", | |
2476 | max_distance, VMALLOC_TOTAL); | |
2477 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK | |
2478 | /* and fail if we have fallback */ | |
2479 | rc = -EINVAL; | |
2480 | goto out_free_areas; | |
2481 | #endif | |
42b64281 TH |
2482 | } |
2483 | ||
2484 | /* | |
2485 | * Copy data and free unused parts. This should happen after all | |
2486 | * allocations are complete; otherwise, we may end up with | |
2487 | * overlapping groups. | |
2488 | */ | |
2489 | for (group = 0; group < ai->nr_groups; group++) { | |
2490 | struct pcpu_group_info *gi = &ai->groups[group]; | |
2491 | void *ptr = areas[group]; | |
c8826dd5 TH |
2492 | |
2493 | for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { | |
2494 | if (gi->cpu_map[i] == NR_CPUS) { | |
2495 | /* unused unit, free whole */ | |
2496 | free_fn(ptr, ai->unit_size); | |
2497 | continue; | |
2498 | } | |
2499 | /* copy and return the unused part */ | |
2500 | memcpy(ptr, __per_cpu_load, ai->static_size); | |
2501 | free_fn(ptr + size_sum, ai->unit_size - size_sum); | |
2502 | } | |
fa8a7094 | 2503 | } |
66c3a757 | 2504 | |
c8826dd5 | 2505 | /* base address is now known, determine group base offsets */ |
6ea529a2 | 2506 | for (group = 0; group < ai->nr_groups; group++) { |
c8826dd5 | 2507 | ai->groups[group].base_offset = areas[group] - base; |
6ea529a2 | 2508 | } |
c8826dd5 | 2509 | |
870d4b12 | 2510 | pr_info("Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", |
fd1e8a1f TH |
2511 | PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, |
2512 | ai->dyn_size, ai->unit_size); | |
d4b95f80 | 2513 | |
fb435d52 | 2514 | rc = pcpu_setup_first_chunk(ai, base); |
c8826dd5 TH |
2515 | goto out_free; |
2516 | ||
2517 | out_free_areas: | |
2518 | for (group = 0; group < ai->nr_groups; group++) | |
f851c8d8 MH |
2519 | if (areas[group]) |
2520 | free_fn(areas[group], | |
2521 | ai->groups[group].nr_units * ai->unit_size); | |
c8826dd5 | 2522 | out_free: |
fd1e8a1f | 2523 | pcpu_free_alloc_info(ai); |
c8826dd5 | 2524 | if (areas) |
999c17e3 | 2525 | memblock_free_early(__pa(areas), areas_size); |
fb435d52 | 2526 | return rc; |
d4b95f80 | 2527 | } |
3c9a024f | 2528 | #endif /* BUILD_EMBED_FIRST_CHUNK */ |
d4b95f80 | 2529 | |
3c9a024f | 2530 | #ifdef BUILD_PAGE_FIRST_CHUNK |
d4b95f80 | 2531 | /** |
00ae4064 | 2532 | * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages |
d4b95f80 TH |
2533 | * @reserved_size: the size of reserved percpu area in bytes |
2534 | * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE | |
25985edc | 2535 | * @free_fn: function to free percpu page, always called with PAGE_SIZE |
d4b95f80 TH |
2536 | * @populate_pte_fn: function to populate pte |
2537 | * | |
00ae4064 TH |
2538 | * This is a helper to ease setting up page-remapped first percpu |
2539 | * chunk and can be called where pcpu_setup_first_chunk() is expected. | |
d4b95f80 TH |
2540 | * |
2541 | * This is the basic allocator. Static percpu area is allocated | |
2542 | * page-by-page into vmalloc area. | |
2543 | * | |
2544 | * RETURNS: | |
fb435d52 | 2545 | * 0 on success, -errno on failure. |
d4b95f80 | 2546 | */ |
fb435d52 TH |
2547 | int __init pcpu_page_first_chunk(size_t reserved_size, |
2548 | pcpu_fc_alloc_fn_t alloc_fn, | |
2549 | pcpu_fc_free_fn_t free_fn, | |
2550 | pcpu_fc_populate_pte_fn_t populate_pte_fn) | |
d4b95f80 | 2551 | { |
8f05a6a6 | 2552 | static struct vm_struct vm; |
fd1e8a1f | 2553 | struct pcpu_alloc_info *ai; |
00ae4064 | 2554 | char psize_str[16]; |
ce3141a2 | 2555 | int unit_pages; |
d4b95f80 | 2556 | size_t pages_size; |
ce3141a2 | 2557 | struct page **pages; |
fb435d52 | 2558 | int unit, i, j, rc; |
8f606604 | 2559 | int upa; |
2560 | int nr_g0_units; | |
d4b95f80 | 2561 | |
00ae4064 TH |
2562 | snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); |
2563 | ||
4ba6ce25 | 2564 | ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL); |
fd1e8a1f TH |
2565 | if (IS_ERR(ai)) |
2566 | return PTR_ERR(ai); | |
2567 | BUG_ON(ai->nr_groups != 1); | |
8f606604 | 2568 | upa = ai->alloc_size/ai->unit_size; |
2569 | nr_g0_units = roundup(num_possible_cpus(), upa); | |
2570 | if (unlikely(WARN_ON(ai->groups[0].nr_units != nr_g0_units))) { | |
2571 | pcpu_free_alloc_info(ai); | |
2572 | return -EINVAL; | |
2573 | } | |
fd1e8a1f TH |
2574 | |
2575 | unit_pages = ai->unit_size >> PAGE_SHIFT; | |
d4b95f80 TH |
2576 | |
2577 | /* unaligned allocations can't be freed, round up to page size */ | |
fd1e8a1f TH |
2578 | pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * |
2579 | sizeof(pages[0])); | |
999c17e3 | 2580 | pages = memblock_virt_alloc(pages_size, 0); |
d4b95f80 | 2581 | |
8f05a6a6 | 2582 | /* allocate pages */ |
d4b95f80 | 2583 | j = 0; |
8f606604 | 2584 | for (unit = 0; unit < num_possible_cpus(); unit++) { |
2585 | unsigned int cpu = ai->groups[0].cpu_map[unit]; | |
ce3141a2 | 2586 | for (i = 0; i < unit_pages; i++) { |
d4b95f80 TH |
2587 | void *ptr; |
2588 | ||
3cbc8565 | 2589 | ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); |
d4b95f80 | 2590 | if (!ptr) { |
870d4b12 | 2591 | pr_warn("failed to allocate %s page for cpu%u\n", |
8f606604 | 2592 | psize_str, cpu); |
d4b95f80 TH |
2593 | goto enomem; |
2594 | } | |
f528f0b8 CM |
2595 | /* kmemleak tracks the percpu allocations separately */ |
2596 | kmemleak_free(ptr); | |
ce3141a2 | 2597 | pages[j++] = virt_to_page(ptr); |
d4b95f80 | 2598 | } |
8f606604 | 2599 | } |
d4b95f80 | 2600 | |
8f05a6a6 TH |
2601 | /* allocate vm area, map the pages and copy static data */ |
2602 | vm.flags = VM_ALLOC; | |
fd1e8a1f | 2603 | vm.size = num_possible_cpus() * ai->unit_size; |
8f05a6a6 TH |
2604 | vm_area_register_early(&vm, PAGE_SIZE); |
2605 | ||
fd1e8a1f | 2606 | for (unit = 0; unit < num_possible_cpus(); unit++) { |
1d9d3257 | 2607 | unsigned long unit_addr = |
fd1e8a1f | 2608 | (unsigned long)vm.addr + unit * ai->unit_size; |
8f05a6a6 | 2609 | |
ce3141a2 | 2610 | for (i = 0; i < unit_pages; i++) |
8f05a6a6 TH |
2611 | populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); |
2612 | ||
2613 | /* pte already populated, the following shouldn't fail */ | |
fb435d52 TH |
2614 | rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], |
2615 | unit_pages); | |
2616 | if (rc < 0) | |
2617 | panic("failed to map percpu area, err=%d\n", rc); | |
66c3a757 | 2618 | |
8f05a6a6 TH |
2619 | /* |
2620 | * FIXME: Archs with virtual cache should flush local | |
2621 | * cache for the linear mapping here - something | |
2622 | * equivalent to flush_cache_vmap() on the local cpu. | |
2623 | * flush_cache_vmap() can't be used as most supporting | |
2624 | * data structures are not set up yet. | |
2625 | */ | |
2626 | ||
2627 | /* copy static data */ | |
fd1e8a1f | 2628 | memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); |
66c3a757 TH |
2629 | } |
2630 | ||
2631 | /* we're ready, commit */ | |
870d4b12 | 2632 | pr_info("%d %s pages/cpu @%p s%zu r%zu d%zu\n", |
fd1e8a1f TH |
2633 | unit_pages, psize_str, vm.addr, ai->static_size, |
2634 | ai->reserved_size, ai->dyn_size); | |
d4b95f80 | 2635 | |
fb435d52 | 2636 | rc = pcpu_setup_first_chunk(ai, vm.addr); |
d4b95f80 TH |
2637 | goto out_free_ar; |
2638 | ||
2639 | enomem: | |
2640 | while (--j >= 0) | |
ce3141a2 | 2641 | free_fn(page_address(pages[j]), PAGE_SIZE); |
fb435d52 | 2642 | rc = -ENOMEM; |
d4b95f80 | 2643 | out_free_ar: |
999c17e3 | 2644 | memblock_free_early(__pa(pages), pages_size); |
fd1e8a1f | 2645 | pcpu_free_alloc_info(ai); |
fb435d52 | 2646 | return rc; |
d4b95f80 | 2647 | } |
3c9a024f | 2648 | #endif /* BUILD_PAGE_FIRST_CHUNK */ |
d4b95f80 | 2649 | |
bbddff05 | 2650 | #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA |
e74e3962 | 2651 | /* |
bbddff05 | 2652 | * Generic SMP percpu area setup. |
e74e3962 TH |
2653 | * |
2654 | * The embedding helper is used because its behavior closely resembles | |
2655 | * the original non-dynamic generic percpu area setup. This is | |
2656 | * important because many archs have addressing restrictions and might | |
2657 | * fail if the percpu area is located far away from the previous | |
2658 | * location. As an added bonus, in non-NUMA cases, embedding is | |
2659 | * generally a good idea TLB-wise because percpu area can piggy back | |
2660 | * on the physical linear memory mapping which uses large page | |
2661 | * mappings on applicable archs. | |
2662 | */ | |
e74e3962 TH |
2663 | unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; |
2664 | EXPORT_SYMBOL(__per_cpu_offset); | |
2665 | ||
c8826dd5 TH |
2666 | static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, |
2667 | size_t align) | |
2668 | { | |
999c17e3 SS |
2669 | return memblock_virt_alloc_from_nopanic( |
2670 | size, align, __pa(MAX_DMA_ADDRESS)); | |
c8826dd5 | 2671 | } |
66c3a757 | 2672 | |
c8826dd5 TH |
2673 | static void __init pcpu_dfl_fc_free(void *ptr, size_t size) |
2674 | { | |
999c17e3 | 2675 | memblock_free_early(__pa(ptr), size); |
c8826dd5 TH |
2676 | } |
2677 | ||
e74e3962 TH |
2678 | void __init setup_per_cpu_areas(void) |
2679 | { | |
e74e3962 TH |
2680 | unsigned long delta; |
2681 | unsigned int cpu; | |
fb435d52 | 2682 | int rc; |
e74e3962 TH |
2683 | |
2684 | /* | |
2685 | * Always reserve area for module percpu variables. That's | |
2686 | * what the legacy allocator did. | |
2687 | */ | |
fb435d52 | 2688 | rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, |
c8826dd5 TH |
2689 | PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, |
2690 | pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); | |
fb435d52 | 2691 | if (rc < 0) |
bbddff05 | 2692 | panic("Failed to initialize percpu areas."); |
e74e3962 TH |
2693 | |
2694 | delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; | |
2695 | for_each_possible_cpu(cpu) | |
fb435d52 | 2696 | __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; |
66c3a757 | 2697 | } |
bbddff05 TH |
2698 | #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ |
2699 | ||
2700 | #else /* CONFIG_SMP */ | |
2701 | ||
2702 | /* | |
2703 | * UP percpu area setup. | |
2704 | * | |
2705 | * UP always uses km-based percpu allocator with identity mapping. | |
2706 | * Static percpu variables are indistinguishable from the usual static | |
2707 | * variables and don't require any special preparation. | |
2708 | */ | |
2709 | void __init setup_per_cpu_areas(void) | |
2710 | { | |
2711 | const size_t unit_size = | |
2712 | roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE, | |
2713 | PERCPU_DYNAMIC_RESERVE)); | |
2714 | struct pcpu_alloc_info *ai; | |
2715 | void *fc; | |
2716 | ||
2717 | ai = pcpu_alloc_alloc_info(1, 1); | |
999c17e3 SS |
2718 | fc = memblock_virt_alloc_from_nopanic(unit_size, |
2719 | PAGE_SIZE, | |
2720 | __pa(MAX_DMA_ADDRESS)); | |
bbddff05 TH |
2721 | if (!ai || !fc) |
2722 | panic("Failed to allocate memory for percpu areas."); | |
100d13c3 CM |
2723 | /* kmemleak tracks the percpu allocations separately */ |
2724 | kmemleak_free(fc); | |
bbddff05 TH |
2725 | |
2726 | ai->dyn_size = unit_size; | |
2727 | ai->unit_size = unit_size; | |
2728 | ai->atom_size = unit_size; | |
2729 | ai->alloc_size = unit_size; | |
2730 | ai->groups[0].nr_units = 1; | |
2731 | ai->groups[0].cpu_map[0] = 0; | |
2732 | ||
2733 | if (pcpu_setup_first_chunk(ai, fc) < 0) | |
2734 | panic("Failed to initialize percpu areas."); | |
2735 | } | |
2736 | ||
2737 | #endif /* CONFIG_SMP */ | |
099a19d9 | 2738 | |
1a4d7607 TH |
2739 | /* |
2740 | * Percpu allocator is initialized early during boot when neither slab or | |
2741 | * workqueue is available. Plug async management until everything is up | |
2742 | * and running. | |
2743 | */ | |
2744 | static int __init percpu_enable_async(void) | |
2745 | { | |
2746 | pcpu_async_enabled = true; | |
2747 | return 0; | |
2748 | } | |
2749 | subsys_initcall(percpu_enable_async); |