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 static inline size_t chunk_size(const struct gen_pool_chunk *chunk)
39 {
40 return chunk->end_addr - chunk->start_addr + 1;
41 }
42
43 static int set_bits_ll(unsigned long *addr, unsigned long mask_to_set)
44 {
45 unsigned long val, nval;
46
47 nval = *addr;
48 do {
49 val = nval;
50 if (val & mask_to_set)
51 return -EBUSY;
52 cpu_relax();
53 } while ((nval = cmpxchg(addr, val, val | mask_to_set)) != val);
54
55 return 0;
56 }
57
58 static int clear_bits_ll(unsigned long *addr, unsigned long mask_to_clear)
59 {
60 unsigned long val, nval;
61
62 nval = *addr;
63 do {
64 val = nval;
65 if ((val & mask_to_clear) != mask_to_clear)
66 return -EBUSY;
67 cpu_relax();
68 } 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 static int bitmap_set_ll(unsigned long *map, int start, int nr)
85 {
86 unsigned long *p = map + BIT_WORD(start);
87 const int size = start + nr;
88 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
89 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
90
91 while (nr - bits_to_set >= 0) {
92 if (set_bits_ll(p, mask_to_set))
93 return nr;
94 nr -= bits_to_set;
95 bits_to_set = BITS_PER_LONG;
96 mask_to_set = ~0UL;
97 p++;
98 }
99 if (nr) {
100 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
101 if (set_bits_ll(p, mask_to_set))
102 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 static int bitmap_clear_ll(unsigned long *map, int start, int nr)
120 {
121 unsigned long *p = map + BIT_WORD(start);
122 const int size = start + nr;
123 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
124 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
125
126 while (nr - bits_to_clear >= 0) {
127 if (clear_bits_ll(p, mask_to_clear))
128 return nr;
129 nr -= bits_to_clear;
130 bits_to_clear = BITS_PER_LONG;
131 mask_to_clear = ~0UL;
132 p++;
133 }
134 if (nr) {
135 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
136 if (clear_bits_ll(p, mask_to_clear))
137 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 struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
152 {
153 struct gen_pool *pool;
154
155 pool = kmalloc_node(sizeof(struct gen_pool), GFP_KERNEL, nid);
156 if (pool != NULL) {
157 spin_lock_init(&pool->lock);
158 INIT_LIST_HEAD(&pool->chunks);
159 pool->min_alloc_order = min_alloc_order;
160 pool->algo = gen_pool_first_fit;
161 pool->data = NULL;
162 pool->name = NULL;
163 }
164 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 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 struct gen_pool_chunk *chunk;
186 int nbits = size >> pool->min_alloc_order;
187 int nbytes = sizeof(struct gen_pool_chunk) +
188 BITS_TO_LONGS(nbits) * sizeof(long);
189
190 chunk = vzalloc_node(nbytes, nid);
191 if (unlikely(chunk == NULL))
192 return -ENOMEM;
193
194 chunk->phys_addr = phys;
195 chunk->start_addr = virt;
196 chunk->end_addr = virt + size - 1;
197 chunk->owner = owner;
198 atomic_long_set(&chunk->avail, size);
199
200 spin_lock(&pool->lock);
201 list_add_rcu(&chunk->next_chunk, &pool->chunks);
202 spin_unlock(&pool->lock);
203
204 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 phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long addr)
216 {
217 struct gen_pool_chunk *chunk;
218 phys_addr_t paddr = -1;
219
220 rcu_read_lock();
221 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
222 if (addr >= chunk->start_addr && addr <= chunk->end_addr) {
223 paddr = chunk->phys_addr + (addr - chunk->start_addr);
224 break;
225 }
226 }
227 rcu_read_unlock();
228
229 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 void gen_pool_destroy(struct gen_pool *pool)
241 {
242 struct list_head *_chunk, *_next_chunk;
243 struct gen_pool_chunk *chunk;
244 int order = pool->min_alloc_order;
245 int bit, end_bit;
246
247 list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
248 chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
249 list_del(&chunk->next_chunk);
250
251 end_bit = chunk_size(chunk) >> order;
252 bit = find_next_bit(chunk->bits, end_bit, 0);
253 BUG_ON(bit < end_bit);
254
255 vfree(chunk);
256 }
257 kfree_const(pool->name);
258 kfree(pool);
259 }
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 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 struct gen_pool_chunk *chunk;
279 unsigned long addr = 0;
280 int order = pool->min_alloc_order;
281 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 if (owner)
288 *owner = NULL;
289
290 if (size == 0)
291 return 0;
292
293 nbits = (size + (1UL << order) - 1) >> order;
294 rcu_read_lock();
295 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
296 if (size > atomic_long_read(&chunk->avail))
297 continue;
298
299 start_bit = 0;
300 end_bit = chunk_size(chunk) >> order;
301 retry:
302 start_bit = algo(chunk->bits, end_bit, start_bit,
303 nbits, data, pool, chunk->start_addr);
304 if (start_bit >= end_bit)
305 continue;
306 remain = bitmap_set_ll(chunk->bits, start_bit, nbits);
307 if (remain) {
308 remain = bitmap_clear_ll(chunk->bits, start_bit,
309 nbits - remain);
310 BUG_ON(remain);
311 goto retry;
312 }
313
314 addr = chunk->start_addr + ((unsigned long)start_bit << order);
315 size = nbits << order;
316 atomic_long_sub(size, &chunk->avail);
317 if (owner)
318 *owner = chunk->owner;
319 break;
320 }
321 rcu_read_unlock();
322 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 void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
340 {
341 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 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 unsigned long vaddr;
364
365 if (!pool)
366 return NULL;
367
368 vaddr = gen_pool_alloc_algo(pool, size, algo, data);
369 if (!vaddr)
370 return NULL;
371
372 if (dma)
373 *dma = gen_pool_virt_to_phys(pool, vaddr);
374
375 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 void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size,
394 dma_addr_t *dma, int align)
395 {
396 struct genpool_data_align data = { .align = align };
397
398 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 void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
418 {
419 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 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 void *vaddr = gen_pool_dma_alloc_algo(pool, size, dma, algo, data);
442
443 if (vaddr)
444 memset(vaddr, 0, size);
445
446 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 void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size,
465 dma_addr_t *dma, int align)
466 {
467 struct genpool_data_align data = { .align = align };
468
469 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 - 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 void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, size_t size,
486 void **owner)
487 {
488 struct gen_pool_chunk *chunk;
489 int order = pool->min_alloc_order;
490 int start_bit, nbits, remain;
491
492 #ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
493 BUG_ON(in_nmi());
494 #endif
495
496 if (owner)
497 *owner = NULL;
498
499 nbits = (size + (1UL << order) - 1) >> order;
500 rcu_read_lock();
501 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
502 if (addr >= chunk->start_addr && addr <= chunk->end_addr) {
503 BUG_ON(addr + size - 1 > chunk->end_addr);
504 start_bit = (addr - chunk->start_addr) >> order;
505 remain = bitmap_clear_ll(chunk->bits, start_bit, nbits);
506 BUG_ON(remain);
507 size = nbits << order;
508 atomic_long_add(size, &chunk->avail);
509 if (owner)
510 *owner = chunk->owner;
511 rcu_read_unlock();
512 return;
513 }
514 }
515 rcu_read_unlock();
516 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 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 struct gen_pool_chunk *chunk;
534
535 rcu_read_lock();
536 list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk)
537 func(pool, chunk, data);
538 rcu_read_unlock();
539 }
540 EXPORT_SYMBOL(gen_pool_for_each_chunk);
541
542 /**
543 * addr_in_gen_pool - 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 bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
552 size_t size)
553 {
554 bool found = false;
555 unsigned long end = start + size - 1;
556 struct gen_pool_chunk *chunk;
557
558 rcu_read_lock();
559 list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk) {
560 if (start >= chunk->start_addr && start <= chunk->end_addr) {
561 if (end <= chunk->end_addr) {
562 found = true;
563 break;
564 }
565 }
566 }
567 rcu_read_unlock();
568 return found;
569 }
570
571 /**
572 * gen_pool_avail - get available free space of the pool
573 * @pool: pool to get available free space
574 *
575 * Return available free space of the specified pool.
576 */
577 size_t gen_pool_avail(struct gen_pool *pool)
578 {
579 struct gen_pool_chunk *chunk;
580 size_t avail = 0;
581
582 rcu_read_lock();
583 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
584 avail += atomic_long_read(&chunk->avail);
585 rcu_read_unlock();
586 return avail;
587 }
588 EXPORT_SYMBOL_GPL(gen_pool_avail);
589
590 /**
591 * gen_pool_size - get size in bytes of memory managed by the pool
592 * @pool: pool to get size
593 *
594 * Return size in bytes of memory managed by the pool.
595 */
596 size_t gen_pool_size(struct gen_pool *pool)
597 {
598 struct gen_pool_chunk *chunk;
599 size_t size = 0;
600
601 rcu_read_lock();
602 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
603 size += chunk_size(chunk);
604 rcu_read_unlock();
605 return size;
606 }
607 EXPORT_SYMBOL_GPL(gen_pool_size);
608
609 /**
610 * gen_pool_set_algo - set the allocation algorithm
611 * @pool: pool to change allocation algorithm
612 * @algo: custom algorithm function
613 * @data: additional data used by @algo
614 *
615 * Call @algo for each memory allocation in the pool.
616 * If @algo is NULL use gen_pool_first_fit as default
617 * memory allocation function.
618 */
619 void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, void *data)
620 {
621 rcu_read_lock();
622
623 pool->algo = algo;
624 if (!pool->algo)
625 pool->algo = gen_pool_first_fit;
626
627 pool->data = data;
628
629 rcu_read_unlock();
630 }
631 EXPORT_SYMBOL(gen_pool_set_algo);
632
633 /**
634 * gen_pool_first_fit - find the first available region
635 * of memory matching the size requirement (no alignment constraint)
636 * @map: The address to base the search on
637 * @size: The bitmap size in bits
638 * @start: The bitnumber to start searching at
639 * @nr: The number of zeroed bits we're looking for
640 * @data: additional data - unused
641 * @pool: pool to find the fit region memory from
642 */
643 unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
644 unsigned long start, unsigned int nr, void *data,
645 struct gen_pool *pool, unsigned long start_addr)
646 {
647 return bitmap_find_next_zero_area(map, size, start, nr, 0);
648 }
649 EXPORT_SYMBOL(gen_pool_first_fit);
650
651 /**
652 * gen_pool_first_fit_align - find the first available region
653 * of memory matching the size requirement (alignment constraint)
654 * @map: The address to base the search on
655 * @size: The bitmap size in bits
656 * @start: The bitnumber to start searching at
657 * @nr: The number of zeroed bits we're looking for
658 * @data: data for alignment
659 * @pool: pool to get order from
660 */
661 unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size,
662 unsigned long start, unsigned int nr, void *data,
663 struct gen_pool *pool, unsigned long start_addr)
664 {
665 struct genpool_data_align *alignment;
666 unsigned long align_mask, align_off;
667 int order;
668
669 alignment = data;
670 order = pool->min_alloc_order;
671 align_mask = ((alignment->align + (1UL << order) - 1) >> order) - 1;
672 align_off = (start_addr & (alignment->align - 1)) >> order;
673
674 return bitmap_find_next_zero_area_off(map, size, start, nr,
675 align_mask, align_off);
676 }
677 EXPORT_SYMBOL(gen_pool_first_fit_align);
678
679 /**
680 * gen_pool_fixed_alloc - reserve a specific region
681 * @map: The address to base the search on
682 * @size: The bitmap size in bits
683 * @start: The bitnumber to start searching at
684 * @nr: The number of zeroed bits we're looking for
685 * @data: data for alignment
686 * @pool: pool to get order from
687 */
688 unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size,
689 unsigned long start, unsigned int nr, void *data,
690 struct gen_pool *pool, unsigned long start_addr)
691 {
692 struct genpool_data_fixed *fixed_data;
693 int order;
694 unsigned long offset_bit;
695 unsigned long start_bit;
696
697 fixed_data = data;
698 order = pool->min_alloc_order;
699 offset_bit = fixed_data->offset >> order;
700 if (WARN_ON(fixed_data->offset & ((1UL << order) - 1)))
701 return size;
702
703 start_bit = bitmap_find_next_zero_area(map, size,
704 start + offset_bit, nr, 0);
705 if (start_bit != offset_bit)
706 start_bit = size;
707 return start_bit;
708 }
709 EXPORT_SYMBOL(gen_pool_fixed_alloc);
710
711 /**
712 * gen_pool_first_fit_order_align - find the first available region
713 * of memory matching the size requirement. The region will be aligned
714 * to the order of the size specified.
715 * @map: The address to base the search on
716 * @size: The bitmap size in bits
717 * @start: The bitnumber to start searching at
718 * @nr: The number of zeroed bits we're looking for
719 * @data: additional data - unused
720 * @pool: pool to find the fit region memory from
721 */
722 unsigned long gen_pool_first_fit_order_align(unsigned long *map,
723 unsigned long size, unsigned long start,
724 unsigned int nr, void *data, struct gen_pool *pool,
725 unsigned long start_addr)
726 {
727 unsigned long align_mask = roundup_pow_of_two(nr) - 1;
728
729 return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
730 }
731 EXPORT_SYMBOL(gen_pool_first_fit_order_align);
732
733 /**
734 * gen_pool_best_fit - find the best fitting region of memory
735 * macthing the size requirement (no alignment constraint)
736 * @map: The address to base the search on
737 * @size: The bitmap size in bits
738 * @start: The bitnumber to start searching at
739 * @nr: The number of zeroed bits we're looking for
740 * @data: additional data - unused
741 * @pool: pool to find the fit region memory from
742 *
743 * Iterate over the bitmap to find the smallest free region
744 * which we can allocate the memory.
745 */
746 unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
747 unsigned long start, unsigned int nr, void *data,
748 struct gen_pool *pool, unsigned long start_addr)
749 {
750 unsigned long start_bit = size;
751 unsigned long len = size + 1;
752 unsigned long index;
753
754 index = bitmap_find_next_zero_area(map, size, start, nr, 0);
755
756 while (index < size) {
757 int next_bit = find_next_bit(map, size, index + nr);
758 if ((next_bit - index) < len) {
759 len = next_bit - index;
760 start_bit = index;
761 if (len == nr)
762 return start_bit;
763 }
764 index = bitmap_find_next_zero_area(map, size,
765 next_bit + 1, nr, 0);
766 }
767
768 return start_bit;
769 }
770 EXPORT_SYMBOL(gen_pool_best_fit);
771
772 static void devm_gen_pool_release(struct device *dev, void *res)
773 {
774 gen_pool_destroy(*(struct gen_pool **)res);
775 }
776
777 static int devm_gen_pool_match(struct device *dev, void *res, void *data)
778 {
779 struct gen_pool **p = res;
780
781 /* NULL data matches only a pool without an assigned name */
782 if (!data && !(*p)->name)
783 return 1;
784
785 if (!data || !(*p)->name)
786 return 0;
787
788 return !strcmp((*p)->name, data);
789 }
790
791 /**
792 * gen_pool_get - Obtain the gen_pool (if any) for a device
793 * @dev: device to retrieve the gen_pool from
794 * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
795 *
796 * Returns the gen_pool for the device if one is present, or NULL.
797 */
798 struct gen_pool *gen_pool_get(struct device *dev, const char *name)
799 {
800 struct gen_pool **p;
801
802 p = devres_find(dev, devm_gen_pool_release, devm_gen_pool_match,
803 (void *)name);
804 if (!p)
805 return NULL;
806 return *p;
807 }
808 EXPORT_SYMBOL_GPL(gen_pool_get);
809
810 /**
811 * devm_gen_pool_create - managed gen_pool_create
812 * @dev: device that provides the gen_pool
813 * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
814 * @nid: node selector for allocated gen_pool, %NUMA_NO_NODE for all nodes
815 * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
816 *
817 * Create a new special memory pool that can be used to manage special purpose
818 * memory not managed by the regular kmalloc/kfree interface. The pool will be
819 * automatically destroyed by the device management code.
820 */
821 struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order,
822 int nid, const char *name)
823 {
824 struct gen_pool **ptr, *pool;
825 const char *pool_name = NULL;
826
827 /* Check that genpool to be created is uniquely addressed on device */
828 if (gen_pool_get(dev, name))
829 return ERR_PTR(-EINVAL);
830
831 if (name) {
832 pool_name = kstrdup_const(name, GFP_KERNEL);
833 if (!pool_name)
834 return ERR_PTR(-ENOMEM);
835 }
836
837 ptr = devres_alloc(devm_gen_pool_release, sizeof(*ptr), GFP_KERNEL);
838 if (!ptr)
839 goto free_pool_name;
840
841 pool = gen_pool_create(min_alloc_order, nid);
842 if (!pool)
843 goto free_devres;
844
845 *ptr = pool;
846 pool->name = pool_name;
847 devres_add(dev, ptr);
848
849 return pool;
850
851 free_devres:
852 devres_free(ptr);
853 free_pool_name:
854 kfree_const(pool_name);
855
856 return ERR_PTR(-ENOMEM);
857 }
858 EXPORT_SYMBOL(devm_gen_pool_create);
859
860 #ifdef CONFIG_OF
861 /**
862 * of_gen_pool_get - find a pool by phandle property
863 * @np: device node
864 * @propname: property name containing phandle(s)
865 * @index: index into the phandle array
866 *
867 * Returns the pool that contains the chunk starting at the physical
868 * address of the device tree node pointed at by the phandle property,
869 * or NULL if not found.
870 */
871 struct gen_pool *of_gen_pool_get(struct device_node *np,
872 const char *propname, int index)
873 {
874 struct platform_device *pdev;
875 struct device_node *np_pool, *parent;
876 const char *name = NULL;
877 struct gen_pool *pool = NULL;
878
879 np_pool = of_parse_phandle(np, propname, index);
880 if (!np_pool)
881 return NULL;
882
883 pdev = of_find_device_by_node(np_pool);
884 if (!pdev) {
885 /* Check if named gen_pool is created by parent node device */
886 parent = of_get_parent(np_pool);
887 pdev = of_find_device_by_node(parent);
888 of_node_put(parent);
889
890 of_property_read_string(np_pool, "label", &name);
891 if (!name)
892 name = np_pool->name;
893 }
894 if (pdev)
895 pool = gen_pool_get(&pdev->dev, name);
896 of_node_put(np_pool);
897
898 return pool;
899 }
900 EXPORT_SYMBOL_GPL(of_gen_pool_get);
901 #endif /* CONFIG_OF */