Branch data Line data Source code
1 : : // SPDX-License-Identifier: GPL-2.0-only
2 : : /*
3 : : * Basic general purpose allocator for managing special purpose
4 : : * memory, for example, memory that is not managed by the regular
5 : : * kmalloc/kfree interface. Uses for this includes on-device special
6 : : * memory, uncached memory etc.
7 : : *
8 : : * It is safe to use the allocator in NMI handlers and other special
9 : : * unblockable contexts that could otherwise deadlock on locks. This
10 : : * is implemented by using atomic operations and retries on any
11 : : * conflicts. The disadvantage is that there may be livelocks in
12 : : * extreme cases. For better scalability, one allocator can be used
13 : : * for each CPU.
14 : : *
15 : : * The lockless operation only works if there is enough memory
16 : : * available. If new memory is added to the pool a lock has to be
17 : : * still taken. So any user relying on locklessness has to ensure
18 : : * that sufficient memory is preallocated.
19 : : *
20 : : * The basic atomic operation of this allocator is cmpxchg on long.
21 : : * On architectures that don't have NMI-safe cmpxchg implementation,
22 : : * the allocator can NOT be used in NMI handler. So code uses the
23 : : * allocator in NMI handler should depend on
24 : : * CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
25 : : *
26 : : * Copyright 2005 (C) Jes Sorensen <jes@trained-monkey.org>
27 : : */
28 : :
29 : : #include <linux/slab.h>
30 : : #include <linux/export.h>
31 : : #include <linux/bitmap.h>
32 : : #include <linux/rculist.h>
33 : : #include <linux/interrupt.h>
34 : : #include <linux/genalloc.h>
35 : : #include <linux/of_device.h>
36 : : #include <linux/vmalloc.h>
37 : :
38 : 0 : static inline size_t chunk_size(const struct gen_pool_chunk *chunk)
39 : : {
40 : 0 : return chunk->end_addr - chunk->start_addr + 1;
41 : : }
42 : :
43 : 0 : static int set_bits_ll(unsigned long *addr, unsigned long mask_to_set)
44 : : {
45 : 0 : unsigned long val, nval;
46 : :
47 : 0 : nval = *addr;
48 : 0 : do {
49 : 0 : val = nval;
50 [ # # ]: 0 : if (val & mask_to_set)
51 : : return -EBUSY;
52 : 0 : cpu_relax();
53 [ # # ]: 0 : } while ((nval = cmpxchg(addr, val, val | mask_to_set)) != val);
54 : :
55 : : return 0;
56 : : }
57 : :
58 : 0 : static int clear_bits_ll(unsigned long *addr, unsigned long mask_to_clear)
59 : : {
60 : 0 : unsigned long val, nval;
61 : :
62 : 0 : nval = *addr;
63 : 0 : do {
64 : 0 : val = nval;
65 [ # # ]: 0 : if ((val & mask_to_clear) != mask_to_clear)
66 : : return -EBUSY;
67 : 0 : cpu_relax();
68 [ # # ]: 0 : } while ((nval = cmpxchg(addr, val, val & ~mask_to_clear)) != val);
69 : :
70 : : return 0;
71 : : }
72 : :
73 : : /*
74 : : * bitmap_set_ll - set the specified number of bits at the specified position
75 : : * @map: pointer to a bitmap
76 : : * @start: a bit position in @map
77 : : * @nr: number of bits to set
78 : : *
79 : : * Set @nr bits start from @start in @map lock-lessly. Several users
80 : : * can set/clear the same bitmap simultaneously without lock. If two
81 : : * users set the same bit, one user will return remain bits, otherwise
82 : : * return 0.
83 : : */
84 : 0 : static int bitmap_set_ll(unsigned long *map, int start, int nr)
85 : : {
86 : 0 : unsigned long *p = map + BIT_WORD(start);
87 : 0 : const int size = start + nr;
88 : 0 : int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
89 : 0 : unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
90 : :
91 [ # # ]: 0 : while (nr - bits_to_set >= 0) {
92 [ # # ]: 0 : if (set_bits_ll(p, mask_to_set))
93 : 0 : return nr;
94 : 0 : nr -= bits_to_set;
95 : 0 : bits_to_set = BITS_PER_LONG;
96 : 0 : mask_to_set = ~0UL;
97 : 0 : p++;
98 : : }
99 [ # # ]: 0 : if (nr) {
100 : 0 : mask_to_set &= BITMAP_LAST_WORD_MASK(size);
101 [ # # ]: 0 : if (set_bits_ll(p, mask_to_set))
102 : 0 : return nr;
103 : : }
104 : :
105 : : return 0;
106 : : }
107 : :
108 : : /*
109 : : * bitmap_clear_ll - clear the specified number of bits at the specified position
110 : : * @map: pointer to a bitmap
111 : : * @start: a bit position in @map
112 : : * @nr: number of bits to set
113 : : *
114 : : * Clear @nr bits start from @start in @map lock-lessly. Several users
115 : : * can set/clear the same bitmap simultaneously without lock. If two
116 : : * users clear the same bit, one user will return remain bits,
117 : : * otherwise return 0.
118 : : */
119 : 0 : static int bitmap_clear_ll(unsigned long *map, int start, int nr)
120 : : {
121 : 0 : unsigned long *p = map + BIT_WORD(start);
122 : 0 : const int size = start + nr;
123 : 0 : int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
124 : 0 : unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
125 : :
126 [ # # ]: 0 : while (nr - bits_to_clear >= 0) {
127 [ # # ]: 0 : if (clear_bits_ll(p, mask_to_clear))
128 : 0 : return nr;
129 : 0 : nr -= bits_to_clear;
130 : 0 : bits_to_clear = BITS_PER_LONG;
131 : 0 : mask_to_clear = ~0UL;
132 : 0 : p++;
133 : : }
134 [ # # ]: 0 : if (nr) {
135 : 0 : mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
136 [ # # ]: 0 : if (clear_bits_ll(p, mask_to_clear))
137 : 0 : return nr;
138 : : }
139 : :
140 : : return 0;
141 : : }
142 : :
143 : : /**
144 : : * gen_pool_create - create a new special memory pool
145 : : * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
146 : : * @nid: node id of the node the pool structure should be allocated on, or -1
147 : : *
148 : : * Create a new special memory pool that can be used to manage special purpose
149 : : * memory not managed by the regular kmalloc/kfree interface.
150 : : */
151 : 30 : struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
152 : : {
153 : 30 : struct gen_pool *pool;
154 : :
155 : 30 : pool = kmalloc_node(sizeof(struct gen_pool), GFP_KERNEL, nid);
156 [ + - ]: 30 : if (pool != NULL) {
157 : 30 : spin_lock_init(&pool->lock);
158 : 30 : INIT_LIST_HEAD(&pool->chunks);
159 : 30 : pool->min_alloc_order = min_alloc_order;
160 : 30 : pool->algo = gen_pool_first_fit;
161 : 30 : pool->data = NULL;
162 : 30 : pool->name = NULL;
163 : : }
164 : 30 : return pool;
165 : : }
166 : : EXPORT_SYMBOL(gen_pool_create);
167 : :
168 : : /**
169 : : * gen_pool_add_owner- add a new chunk of special memory to the pool
170 : : * @pool: pool to add new memory chunk to
171 : : * @virt: virtual starting address of memory chunk to add to pool
172 : : * @phys: physical starting address of memory chunk to add to pool
173 : : * @size: size in bytes of the memory chunk to add to pool
174 : : * @nid: node id of the node the chunk structure and bitmap should be
175 : : * allocated on, or -1
176 : : * @owner: private data the publisher would like to recall at alloc time
177 : : *
178 : : * Add a new chunk of special memory to the specified pool.
179 : : *
180 : : * Returns 0 on success or a -ve errno on failure.
181 : : */
182 : 30 : int gen_pool_add_owner(struct gen_pool *pool, unsigned long virt, phys_addr_t phys,
183 : : size_t size, int nid, void *owner)
184 : : {
185 : 30 : struct gen_pool_chunk *chunk;
186 : 30 : int nbits = size >> pool->min_alloc_order;
187 : 30 : int nbytes = sizeof(struct gen_pool_chunk) +
188 : 30 : BITS_TO_LONGS(nbits) * sizeof(long);
189 : :
190 : 30 : chunk = vzalloc_node(nbytes, nid);
191 [ + - ]: 30 : if (unlikely(chunk == NULL))
192 : : return -ENOMEM;
193 : :
194 : 30 : chunk->phys_addr = phys;
195 : 30 : chunk->start_addr = virt;
196 : 30 : chunk->end_addr = virt + size - 1;
197 : 30 : chunk->owner = owner;
198 : 30 : atomic_long_set(&chunk->avail, size);
199 : :
200 : 30 : spin_lock(&pool->lock);
201 : 30 : list_add_rcu(&chunk->next_chunk, &pool->chunks);
202 : 30 : spin_unlock(&pool->lock);
203 : :
204 : 30 : return 0;
205 : : }
206 : : EXPORT_SYMBOL(gen_pool_add_owner);
207 : :
208 : : /**
209 : : * gen_pool_virt_to_phys - return the physical address of memory
210 : : * @pool: pool to allocate from
211 : : * @addr: starting address of memory
212 : : *
213 : : * Returns the physical address on success, or -1 on error.
214 : : */
215 : 0 : phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long addr)
216 : : {
217 : 0 : struct gen_pool_chunk *chunk;
218 : 0 : phys_addr_t paddr = -1;
219 : :
220 : 0 : rcu_read_lock();
221 [ # # # # ]: 0 : list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
222 [ # # # # : 0 : if (addr >= chunk->start_addr && addr <= chunk->end_addr) {
# # # # ]
223 : 0 : paddr = chunk->phys_addr + (addr - chunk->start_addr);
224 : 0 : break;
225 : : }
226 : : }
227 : 0 : rcu_read_unlock();
228 : :
229 : 0 : return paddr;
230 : : }
231 : : EXPORT_SYMBOL(gen_pool_virt_to_phys);
232 : :
233 : : /**
234 : : * gen_pool_destroy - destroy a special memory pool
235 : : * @pool: pool to destroy
236 : : *
237 : : * Destroy the specified special memory pool. Verifies that there are no
238 : : * outstanding allocations.
239 : : */
240 : 0 : void gen_pool_destroy(struct gen_pool *pool)
241 : : {
242 : 0 : struct list_head *_chunk, *_next_chunk;
243 : 0 : struct gen_pool_chunk *chunk;
244 : 0 : int order = pool->min_alloc_order;
245 : 0 : int bit, end_bit;
246 : :
247 [ # # ]: 0 : list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
248 : 0 : chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
249 : 0 : list_del(&chunk->next_chunk);
250 : :
251 : 0 : end_bit = chunk_size(chunk) >> order;
252 : 0 : bit = find_next_bit(chunk->bits, end_bit, 0);
253 [ # # ]: 0 : BUG_ON(bit < end_bit);
254 : :
255 : 0 : vfree(chunk);
256 : : }
257 : 0 : kfree_const(pool->name);
258 : 0 : kfree(pool);
259 : 0 : }
260 : : EXPORT_SYMBOL(gen_pool_destroy);
261 : :
262 : : /**
263 : : * gen_pool_alloc_algo_owner - allocate special memory from the pool
264 : : * @pool: pool to allocate from
265 : : * @size: number of bytes to allocate from the pool
266 : : * @algo: algorithm passed from caller
267 : : * @data: data passed to algorithm
268 : : * @owner: optionally retrieve the chunk owner
269 : : *
270 : : * Allocate the requested number of bytes from the specified pool.
271 : : * Uses the pool allocation function (with first-fit algorithm by default).
272 : : * Can not be used in NMI handler on architectures without
273 : : * NMI-safe cmpxchg implementation.
274 : : */
275 : 0 : unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size,
276 : : genpool_algo_t algo, void *data, void **owner)
277 : : {
278 : 0 : struct gen_pool_chunk *chunk;
279 : 0 : unsigned long addr = 0;
280 : 0 : int order = pool->min_alloc_order;
281 : 0 : int nbits, start_bit, end_bit, remain;
282 : :
283 : : #ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
284 : : BUG_ON(in_nmi());
285 : : #endif
286 : :
287 [ # # ]: 0 : if (owner)
288 : 0 : *owner = NULL;
289 : :
290 [ # # ]: 0 : if (size == 0)
291 : : return 0;
292 : :
293 : 0 : nbits = (size + (1UL << order) - 1) >> order;
294 : 0 : rcu_read_lock();
295 [ # # ]: 0 : list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
296 [ # # ]: 0 : if (size > atomic_long_read(&chunk->avail))
297 : 0 : continue;
298 : :
299 : 0 : start_bit = 0;
300 : 0 : end_bit = chunk_size(chunk) >> order;
301 : 0 : retry:
302 : 0 : start_bit = algo(chunk->bits, end_bit, start_bit,
303 : : nbits, data, pool, chunk->start_addr);
304 [ # # ]: 0 : if (start_bit >= end_bit)
305 : 0 : continue;
306 : 0 : remain = bitmap_set_ll(chunk->bits, start_bit, nbits);
307 [ # # ]: 0 : if (remain) {
308 : 0 : remain = bitmap_clear_ll(chunk->bits, start_bit,
309 : : nbits - remain);
310 [ # # ]: 0 : BUG_ON(remain);
311 : 0 : goto retry;
312 : : }
313 : :
314 : 0 : addr = chunk->start_addr + ((unsigned long)start_bit << order);
315 : 0 : size = nbits << order;
316 : 0 : atomic_long_sub(size, &chunk->avail);
317 [ # # ]: 0 : if (owner)
318 : 0 : *owner = chunk->owner;
319 : : break;
320 : : }
321 : 0 : rcu_read_unlock();
322 : 0 : return addr;
323 : : }
324 : : EXPORT_SYMBOL(gen_pool_alloc_algo_owner);
325 : :
326 : : /**
327 : : * gen_pool_dma_alloc - allocate special memory from the pool for DMA usage
328 : : * @pool: pool to allocate from
329 : : * @size: number of bytes to allocate from the pool
330 : : * @dma: dma-view physical address return value. Use %NULL if unneeded.
331 : : *
332 : : * Allocate the requested number of bytes from the specified pool.
333 : : * Uses the pool allocation function (with first-fit algorithm by default).
334 : : * Can not be used in NMI handler on architectures without
335 : : * NMI-safe cmpxchg implementation.
336 : : *
337 : : * Return: virtual address of the allocated memory, or %NULL on failure
338 : : */
339 : 0 : void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
340 : : {
341 : 0 : return gen_pool_dma_alloc_algo(pool, size, dma, pool->algo, pool->data);
342 : : }
343 : : EXPORT_SYMBOL(gen_pool_dma_alloc);
344 : :
345 : : /**
346 : : * gen_pool_dma_alloc_algo - allocate special memory from the pool for DMA
347 : : * usage with the given pool algorithm
348 : : * @pool: pool to allocate from
349 : : * @size: number of bytes to allocate from the pool
350 : : * @dma: DMA-view physical address return value. Use %NULL if unneeded.
351 : : * @algo: algorithm passed from caller
352 : : * @data: data passed to algorithm
353 : : *
354 : : * Allocate the requested number of bytes from the specified pool. Uses the
355 : : * given pool allocation function. Can not be used in NMI handler on
356 : : * architectures without NMI-safe cmpxchg implementation.
357 : : *
358 : : * Return: virtual address of the allocated memory, or %NULL on failure
359 : : */
360 : 0 : void *gen_pool_dma_alloc_algo(struct gen_pool *pool, size_t size,
361 : : dma_addr_t *dma, genpool_algo_t algo, void *data)
362 : : {
363 : 0 : unsigned long vaddr;
364 : :
365 [ # # ]: 0 : if (!pool)
366 : : return NULL;
367 : :
368 : 0 : vaddr = gen_pool_alloc_algo(pool, size, algo, data);
369 [ # # ]: 0 : if (!vaddr)
370 : : return NULL;
371 : :
372 [ # # ]: 0 : if (dma)
373 : 0 : *dma = gen_pool_virt_to_phys(pool, vaddr);
374 : :
375 : 0 : return (void *)vaddr;
376 : : }
377 : : EXPORT_SYMBOL(gen_pool_dma_alloc_algo);
378 : :
379 : : /**
380 : : * gen_pool_dma_alloc_align - allocate special memory from the pool for DMA
381 : : * usage with the given alignment
382 : : * @pool: pool to allocate from
383 : : * @size: number of bytes to allocate from the pool
384 : : * @dma: DMA-view physical address return value. Use %NULL if unneeded.
385 : : * @align: alignment in bytes for starting address
386 : : *
387 : : * Allocate the requested number bytes from the specified pool, with the given
388 : : * alignment restriction. Can not be used in NMI handler on architectures
389 : : * without NMI-safe cmpxchg implementation.
390 : : *
391 : : * Return: virtual address of the allocated memory, or %NULL on failure
392 : : */
393 : 0 : void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size,
394 : : dma_addr_t *dma, int align)
395 : : {
396 : 0 : struct genpool_data_align data = { .align = align };
397 : :
398 : 0 : return gen_pool_dma_alloc_algo(pool, size, dma,
399 : : gen_pool_first_fit_align, &data);
400 : : }
401 : : EXPORT_SYMBOL(gen_pool_dma_alloc_align);
402 : :
403 : : /**
404 : : * gen_pool_dma_zalloc - allocate special zeroed memory from the pool for
405 : : * DMA usage
406 : : * @pool: pool to allocate from
407 : : * @size: number of bytes to allocate from the pool
408 : : * @dma: dma-view physical address return value. Use %NULL if unneeded.
409 : : *
410 : : * Allocate the requested number of zeroed bytes from the specified pool.
411 : : * Uses the pool allocation function (with first-fit algorithm by default).
412 : : * Can not be used in NMI handler on architectures without
413 : : * NMI-safe cmpxchg implementation.
414 : : *
415 : : * Return: virtual address of the allocated zeroed memory, or %NULL on failure
416 : : */
417 : 0 : void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
418 : : {
419 : 0 : return gen_pool_dma_zalloc_algo(pool, size, dma, pool->algo, pool->data);
420 : : }
421 : : EXPORT_SYMBOL(gen_pool_dma_zalloc);
422 : :
423 : : /**
424 : : * gen_pool_dma_zalloc_algo - allocate special zeroed memory from the pool for
425 : : * DMA usage with the given pool algorithm
426 : : * @pool: pool to allocate from
427 : : * @size: number of bytes to allocate from the pool
428 : : * @dma: DMA-view physical address return value. Use %NULL if unneeded.
429 : : * @algo: algorithm passed from caller
430 : : * @data: data passed to algorithm
431 : : *
432 : : * Allocate the requested number of zeroed bytes from the specified pool. Uses
433 : : * the given pool allocation function. Can not be used in NMI handler on
434 : : * architectures without NMI-safe cmpxchg implementation.
435 : : *
436 : : * Return: virtual address of the allocated zeroed memory, or %NULL on failure
437 : : */
438 : 0 : void *gen_pool_dma_zalloc_algo(struct gen_pool *pool, size_t size,
439 : : dma_addr_t *dma, genpool_algo_t algo, void *data)
440 : : {
441 : 0 : void *vaddr = gen_pool_dma_alloc_algo(pool, size, dma, algo, data);
442 : :
443 [ # # ]: 0 : if (vaddr)
444 : 0 : memset(vaddr, 0, size);
445 : :
446 : 0 : return vaddr;
447 : : }
448 : : EXPORT_SYMBOL(gen_pool_dma_zalloc_algo);
449 : :
450 : : /**
451 : : * gen_pool_dma_zalloc_align - allocate special zeroed memory from the pool for
452 : : * DMA usage with the given alignment
453 : : * @pool: pool to allocate from
454 : : * @size: number of bytes to allocate from the pool
455 : : * @dma: DMA-view physical address return value. Use %NULL if unneeded.
456 : : * @align: alignment in bytes for starting address
457 : : *
458 : : * Allocate the requested number of zeroed bytes from the specified pool,
459 : : * with the given alignment restriction. Can not be used in NMI handler on
460 : : * architectures without NMI-safe cmpxchg implementation.
461 : : *
462 : : * Return: virtual address of the allocated zeroed memory, or %NULL on failure
463 : : */
464 : 0 : void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size,
465 : : dma_addr_t *dma, int align)
466 : : {
467 : 0 : struct genpool_data_align data = { .align = align };
468 : :
469 : 0 : return gen_pool_dma_zalloc_algo(pool, size, dma,
470 : : gen_pool_first_fit_align, &data);
471 : : }
472 : : EXPORT_SYMBOL(gen_pool_dma_zalloc_align);
473 : :
474 : : /**
475 : : * gen_pool_free_owner - free allocated special memory back to the pool
476 : : * @pool: pool to free to
477 : : * @addr: starting address of memory to free back to pool
478 : : * @size: size in bytes of memory to free
479 : : * @owner: private data stashed at gen_pool_add() time
480 : : *
481 : : * Free previously allocated special memory back to the specified
482 : : * pool. Can not be used in NMI handler on architectures without
483 : : * NMI-safe cmpxchg implementation.
484 : : */
485 : 0 : void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, size_t size,
486 : : void **owner)
487 : : {
488 : 0 : struct gen_pool_chunk *chunk;
489 : 0 : int order = pool->min_alloc_order;
490 : 0 : int start_bit, nbits, remain;
491 : :
492 : : #ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
493 : : BUG_ON(in_nmi());
494 : : #endif
495 : :
496 [ # # ]: 0 : if (owner)
497 : 0 : *owner = NULL;
498 : :
499 : 0 : nbits = (size + (1UL << order) - 1) >> order;
500 : 0 : rcu_read_lock();
501 [ # # ]: 0 : list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
502 [ # # # # ]: 0 : if (addr >= chunk->start_addr && addr <= chunk->end_addr) {
503 [ # # ]: 0 : BUG_ON(addr + size - 1 > chunk->end_addr);
504 : 0 : start_bit = (addr - chunk->start_addr) >> order;
505 : 0 : remain = bitmap_clear_ll(chunk->bits, start_bit, nbits);
506 [ # # ]: 0 : BUG_ON(remain);
507 : 0 : size = nbits << order;
508 : 0 : atomic_long_add(size, &chunk->avail);
509 [ # # ]: 0 : if (owner)
510 : 0 : *owner = chunk->owner;
511 : 0 : rcu_read_unlock();
512 : 0 : return;
513 : : }
514 : : }
515 : 0 : rcu_read_unlock();
516 : 0 : BUG();
517 : : }
518 : : EXPORT_SYMBOL(gen_pool_free_owner);
519 : :
520 : : /**
521 : : * gen_pool_for_each_chunk - call func for every chunk of generic memory pool
522 : : * @pool: the generic memory pool
523 : : * @func: func to call
524 : : * @data: additional data used by @func
525 : : *
526 : : * Call @func for every chunk of generic memory pool. The @func is
527 : : * called with rcu_read_lock held.
528 : : */
529 : 0 : void gen_pool_for_each_chunk(struct gen_pool *pool,
530 : : void (*func)(struct gen_pool *pool, struct gen_pool_chunk *chunk, void *data),
531 : : void *data)
532 : : {
533 : 0 : struct gen_pool_chunk *chunk;
534 : :
535 : 0 : rcu_read_lock();
536 [ # # ]: 0 : list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk)
537 : 0 : func(pool, chunk, data);
538 : 0 : rcu_read_unlock();
539 : 0 : }
540 : : EXPORT_SYMBOL(gen_pool_for_each_chunk);
541 : :
542 : : /**
543 : : * gen_pool_has_addr - checks if an address falls within the range of a pool
544 : : * @pool: the generic memory pool
545 : : * @start: start address
546 : : * @size: size of the region
547 : : *
548 : : * Check if the range of addresses falls within the specified pool. Returns
549 : : * true if the entire range is contained in the pool and false otherwise.
550 : : */
551 : 0 : bool gen_pool_has_addr(struct gen_pool *pool, unsigned long start,
552 : : size_t size)
553 : : {
554 : 0 : bool found = false;
555 : 0 : unsigned long end = start + size - 1;
556 : 0 : struct gen_pool_chunk *chunk;
557 : :
558 : 0 : rcu_read_lock();
559 [ # # ]: 0 : list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk) {
560 [ # # # # ]: 0 : if (start >= chunk->start_addr && start <= chunk->end_addr) {
561 [ # # ]: 0 : if (end <= chunk->end_addr) {
562 : : found = true;
563 : : break;
564 : : }
565 : : }
566 : : }
567 : 0 : rcu_read_unlock();
568 : 0 : return found;
569 : : }
570 : : EXPORT_SYMBOL(gen_pool_has_addr);
571 : :
572 : : /**
573 : : * gen_pool_avail - get available free space of the pool
574 : : * @pool: pool to get available free space
575 : : *
576 : : * Return available free space of the specified pool.
577 : : */
578 : 0 : size_t gen_pool_avail(struct gen_pool *pool)
579 : : {
580 : 0 : struct gen_pool_chunk *chunk;
581 : 0 : size_t avail = 0;
582 : :
583 : 0 : rcu_read_lock();
584 [ # # ]: 0 : list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
585 : 0 : avail += atomic_long_read(&chunk->avail);
586 : 0 : rcu_read_unlock();
587 : 0 : return avail;
588 : : }
589 : : EXPORT_SYMBOL_GPL(gen_pool_avail);
590 : :
591 : : /**
592 : : * gen_pool_size - get size in bytes of memory managed by the pool
593 : : * @pool: pool to get size
594 : : *
595 : : * Return size in bytes of memory managed by the pool.
596 : : */
597 : 0 : size_t gen_pool_size(struct gen_pool *pool)
598 : : {
599 : 0 : struct gen_pool_chunk *chunk;
600 : 0 : size_t size = 0;
601 : :
602 : 0 : rcu_read_lock();
603 [ # # ]: 0 : list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
604 : 0 : size += chunk_size(chunk);
605 : 0 : rcu_read_unlock();
606 : 0 : return size;
607 : : }
608 : : EXPORT_SYMBOL_GPL(gen_pool_size);
609 : :
610 : : /**
611 : : * gen_pool_set_algo - set the allocation algorithm
612 : : * @pool: pool to change allocation algorithm
613 : : * @algo: custom algorithm function
614 : : * @data: additional data used by @algo
615 : : *
616 : : * Call @algo for each memory allocation in the pool.
617 : : * If @algo is NULL use gen_pool_first_fit as default
618 : : * memory allocation function.
619 : : */
620 : 0 : void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, void *data)
621 : : {
622 : 0 : rcu_read_lock();
623 : :
624 : 0 : pool->algo = algo;
625 [ # # ]: 0 : if (!pool->algo)
626 : 0 : pool->algo = gen_pool_first_fit;
627 : :
628 : 0 : pool->data = data;
629 : :
630 : 0 : rcu_read_unlock();
631 : 0 : }
632 : : EXPORT_SYMBOL(gen_pool_set_algo);
633 : :
634 : : /**
635 : : * gen_pool_first_fit - find the first available region
636 : : * of memory matching the size requirement (no alignment constraint)
637 : : * @map: The address to base the search on
638 : : * @size: The bitmap size in bits
639 : : * @start: The bitnumber to start searching at
640 : : * @nr: The number of zeroed bits we're looking for
641 : : * @data: additional data - unused
642 : : * @pool: pool to find the fit region memory from
643 : : */
644 : 0 : unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
645 : : unsigned long start, unsigned int nr, void *data,
646 : : struct gen_pool *pool, unsigned long start_addr)
647 : : {
648 : 0 : return bitmap_find_next_zero_area(map, size, start, nr, 0);
649 : : }
650 : : EXPORT_SYMBOL(gen_pool_first_fit);
651 : :
652 : : /**
653 : : * gen_pool_first_fit_align - find the first available region
654 : : * of memory matching the size requirement (alignment constraint)
655 : : * @map: The address to base the search on
656 : : * @size: The bitmap size in bits
657 : : * @start: The bitnumber to start searching at
658 : : * @nr: The number of zeroed bits we're looking for
659 : : * @data: data for alignment
660 : : * @pool: pool to get order from
661 : : */
662 : 0 : unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size,
663 : : unsigned long start, unsigned int nr, void *data,
664 : : struct gen_pool *pool, unsigned long start_addr)
665 : : {
666 : 0 : struct genpool_data_align *alignment;
667 : 0 : unsigned long align_mask, align_off;
668 : 0 : int order;
669 : :
670 : 0 : alignment = data;
671 : 0 : order = pool->min_alloc_order;
672 : 0 : align_mask = ((alignment->align + (1UL << order) - 1) >> order) - 1;
673 : 0 : align_off = (start_addr & (alignment->align - 1)) >> order;
674 : :
675 : 0 : return bitmap_find_next_zero_area_off(map, size, start, nr,
676 : : align_mask, align_off);
677 : : }
678 : : EXPORT_SYMBOL(gen_pool_first_fit_align);
679 : :
680 : : /**
681 : : * gen_pool_fixed_alloc - reserve a specific region
682 : : * @map: The address to base the search on
683 : : * @size: The bitmap size in bits
684 : : * @start: The bitnumber to start searching at
685 : : * @nr: The number of zeroed bits we're looking for
686 : : * @data: data for alignment
687 : : * @pool: pool to get order from
688 : : */
689 : 0 : unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size,
690 : : unsigned long start, unsigned int nr, void *data,
691 : : struct gen_pool *pool, unsigned long start_addr)
692 : : {
693 : 0 : struct genpool_data_fixed *fixed_data;
694 : 0 : int order;
695 : 0 : unsigned long offset_bit;
696 : 0 : unsigned long start_bit;
697 : :
698 : 0 : fixed_data = data;
699 : 0 : order = pool->min_alloc_order;
700 : 0 : offset_bit = fixed_data->offset >> order;
701 [ # # # # ]: 0 : if (WARN_ON(fixed_data->offset & ((1UL << order) - 1)))
702 : : return size;
703 : :
704 : 0 : start_bit = bitmap_find_next_zero_area(map, size,
705 : : start + offset_bit, nr, 0);
706 [ # # ]: 0 : if (start_bit != offset_bit)
707 : 0 : start_bit = size;
708 : : return start_bit;
709 : : }
710 : : EXPORT_SYMBOL(gen_pool_fixed_alloc);
711 : :
712 : : /**
713 : : * gen_pool_first_fit_order_align - find the first available region
714 : : * of memory matching the size requirement. The region will be aligned
715 : : * to the order of the size specified.
716 : : * @map: The address to base the search on
717 : : * @size: The bitmap size in bits
718 : : * @start: The bitnumber to start searching at
719 : : * @nr: The number of zeroed bits we're looking for
720 : : * @data: additional data - unused
721 : : * @pool: pool to find the fit region memory from
722 : : */
723 : 0 : unsigned long gen_pool_first_fit_order_align(unsigned long *map,
724 : : unsigned long size, unsigned long start,
725 : : unsigned int nr, void *data, struct gen_pool *pool,
726 : : unsigned long start_addr)
727 : : {
728 [ # # # # : 0 : unsigned long align_mask = roundup_pow_of_two(nr) - 1;
# # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # ]
729 : :
730 : 0 : return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
731 : : }
732 : : EXPORT_SYMBOL(gen_pool_first_fit_order_align);
733 : :
734 : : /**
735 : : * gen_pool_best_fit - find the best fitting region of memory
736 : : * macthing the size requirement (no alignment constraint)
737 : : * @map: The address to base the search on
738 : : * @size: The bitmap size in bits
739 : : * @start: The bitnumber to start searching at
740 : : * @nr: The number of zeroed bits we're looking for
741 : : * @data: additional data - unused
742 : : * @pool: pool to find the fit region memory from
743 : : *
744 : : * Iterate over the bitmap to find the smallest free region
745 : : * which we can allocate the memory.
746 : : */
747 : 0 : unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
748 : : unsigned long start, unsigned int nr, void *data,
749 : : struct gen_pool *pool, unsigned long start_addr)
750 : : {
751 : 0 : unsigned long start_bit = size;
752 : 0 : unsigned long len = size + 1;
753 : 0 : unsigned long index;
754 : :
755 : 0 : index = bitmap_find_next_zero_area(map, size, start, nr, 0);
756 : :
757 [ # # ]: 0 : while (index < size) {
758 : 0 : int next_bit = find_next_bit(map, size, index + nr);
759 [ # # ]: 0 : if ((next_bit - index) < len) {
760 : 0 : len = next_bit - index;
761 : 0 : start_bit = index;
762 [ # # ]: 0 : if (len == nr)
763 : 0 : return start_bit;
764 : : }
765 : 0 : index = bitmap_find_next_zero_area(map, size,
766 : 0 : next_bit + 1, nr, 0);
767 : : }
768 : :
769 : : return start_bit;
770 : : }
771 : : EXPORT_SYMBOL(gen_pool_best_fit);
772 : :
773 : 0 : static void devm_gen_pool_release(struct device *dev, void *res)
774 : : {
775 : 0 : gen_pool_destroy(*(struct gen_pool **)res);
776 : 0 : }
777 : :
778 : 0 : static int devm_gen_pool_match(struct device *dev, void *res, void *data)
779 : : {
780 : 0 : struct gen_pool **p = res;
781 : :
782 : : /* NULL data matches only a pool without an assigned name */
783 [ # # # # ]: 0 : if (!data && !(*p)->name)
784 : : return 1;
785 : :
786 [ # # # # ]: 0 : if (!data || !(*p)->name)
787 : : return 0;
788 : :
789 : 0 : return !strcmp((*p)->name, data);
790 : : }
791 : :
792 : : /**
793 : : * gen_pool_get - Obtain the gen_pool (if any) for a device
794 : : * @dev: device to retrieve the gen_pool from
795 : : * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
796 : : *
797 : : * Returns the gen_pool for the device if one is present, or NULL.
798 : : */
799 : 0 : struct gen_pool *gen_pool_get(struct device *dev, const char *name)
800 : : {
801 : 0 : struct gen_pool **p;
802 : :
803 : 0 : p = devres_find(dev, devm_gen_pool_release, devm_gen_pool_match,
804 : : (void *)name);
805 [ # # # # ]: 0 : if (!p)
806 : : return NULL;
807 : 0 : return *p;
808 : : }
809 : : EXPORT_SYMBOL_GPL(gen_pool_get);
810 : :
811 : : /**
812 : : * devm_gen_pool_create - managed gen_pool_create
813 : : * @dev: device that provides the gen_pool
814 : : * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
815 : : * @nid: node selector for allocated gen_pool, %NUMA_NO_NODE for all nodes
816 : : * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
817 : : *
818 : : * Create a new special memory pool that can be used to manage special purpose
819 : : * memory not managed by the regular kmalloc/kfree interface. The pool will be
820 : : * automatically destroyed by the device management code.
821 : : */
822 : 0 : struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order,
823 : : int nid, const char *name)
824 : : {
825 : 0 : struct gen_pool **ptr, *pool;
826 : 0 : const char *pool_name = NULL;
827 : :
828 : : /* Check that genpool to be created is uniquely addressed on device */
829 [ # # ]: 0 : if (gen_pool_get(dev, name))
830 : : return ERR_PTR(-EINVAL);
831 : :
832 [ # # ]: 0 : if (name) {
833 : 0 : pool_name = kstrdup_const(name, GFP_KERNEL);
834 [ # # ]: 0 : if (!pool_name)
835 : : return ERR_PTR(-ENOMEM);
836 : : }
837 : :
838 : 0 : ptr = devres_alloc(devm_gen_pool_release, sizeof(*ptr), GFP_KERNEL);
839 [ # # ]: 0 : if (!ptr)
840 : 0 : goto free_pool_name;
841 : :
842 : 0 : pool = gen_pool_create(min_alloc_order, nid);
843 [ # # ]: 0 : if (!pool)
844 : 0 : goto free_devres;
845 : :
846 : 0 : *ptr = pool;
847 : 0 : pool->name = pool_name;
848 : 0 : devres_add(dev, ptr);
849 : :
850 : 0 : return pool;
851 : :
852 : : free_devres:
853 : 0 : devres_free(ptr);
854 : 0 : free_pool_name:
855 : 0 : kfree_const(pool_name);
856 : :
857 : 0 : return ERR_PTR(-ENOMEM);
858 : : }
859 : : EXPORT_SYMBOL(devm_gen_pool_create);
860 : :
861 : : #ifdef CONFIG_OF
862 : : /**
863 : : * of_gen_pool_get - find a pool by phandle property
864 : : * @np: device node
865 : : * @propname: property name containing phandle(s)
866 : : * @index: index into the phandle array
867 : : *
868 : : * Returns the pool that contains the chunk starting at the physical
869 : : * address of the device tree node pointed at by the phandle property,
870 : : * or NULL if not found.
871 : : */
872 : : struct gen_pool *of_gen_pool_get(struct device_node *np,
873 : : const char *propname, int index)
874 : : {
875 : : struct platform_device *pdev;
876 : : struct device_node *np_pool, *parent;
877 : : const char *name = NULL;
878 : : struct gen_pool *pool = NULL;
879 : :
880 : : np_pool = of_parse_phandle(np, propname, index);
881 : : if (!np_pool)
882 : : return NULL;
883 : :
884 : : pdev = of_find_device_by_node(np_pool);
885 : : if (!pdev) {
886 : : /* Check if named gen_pool is created by parent node device */
887 : : parent = of_get_parent(np_pool);
888 : : pdev = of_find_device_by_node(parent);
889 : : of_node_put(parent);
890 : :
891 : : of_property_read_string(np_pool, "label", &name);
892 : : if (!name)
893 : : name = np_pool->name;
894 : : }
895 : : if (pdev)
896 : : pool = gen_pool_get(&pdev->dev, name);
897 : : of_node_put(np_pool);
898 : :
899 : : return pool;
900 : : }
901 : : EXPORT_SYMBOL_GPL(of_gen_pool_get);
902 : : #endif /* CONFIG_OF */
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