projects/linux·blob v6.5-rc3 · refs

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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 <[email protected]>
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
38static inline size_t chunk_size(const struct gen_pool_chunk *chunk)
39{
40 return chunk->end_addr - chunk->start_addr + 1;
41}
42
43static inline int
44set_bits_ll(unsigned long *addr, unsigned long mask_to_set)
45{
46 unsigned long val = READ_ONCE(*addr);
47
48 do {
49 if (val & mask_to_set)
50 return -EBUSY;
51 cpu_relax();
52 } while (!try_cmpxchg(addr, &val, val | mask_to_set));
53
54 return 0;
55}
56
57static inline int
58clear_bits_ll(unsigned long *addr, unsigned long mask_to_clear)
59{
60 unsigned long val = READ_ONCE(*addr);
61
62 do {
63 if ((val & mask_to_clear) != mask_to_clear)
64 return -EBUSY;
65 cpu_relax();
66 } while (!try_cmpxchg(addr, &val, val & ~mask_to_clear));
67
68 return 0;
69}
70
71/*
72 * bitmap_set_ll - set the specified number of bits at the specified position
73 * @map: pointer to a bitmap
74 * @start: a bit position in @map
75 * @nr: number of bits to set
76 *
77 * Set @nr bits start from @start in @map lock-lessly. Several users
78 * can set/clear the same bitmap simultaneously without lock. If two
79 * users set the same bit, one user will return remain bits, otherwise
80 * return 0.
81 */
82static unsigned long
83bitmap_set_ll(unsigned long *map, unsigned long start, unsigned long nr)
84{
85 unsigned long *p = map + BIT_WORD(start);
86 const unsigned long size = start + nr;
87 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
88 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
89
90 while (nr >= bits_to_set) {
91 if (set_bits_ll(p, mask_to_set))
92 return nr;
93 nr -= bits_to_set;
94 bits_to_set = BITS_PER_LONG;
95 mask_to_set = ~0UL;
96 p++;
97 }
98 if (nr) {
99 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
100 if (set_bits_ll(p, mask_to_set))
101 return nr;
102 }
103
104 return 0;
105}
106
107/*
108 * bitmap_clear_ll - clear the specified number of bits at the specified position
109 * @map: pointer to a bitmap
110 * @start: a bit position in @map
111 * @nr: number of bits to set
112 *
113 * Clear @nr bits start from @start in @map lock-lessly. Several users
114 * can set/clear the same bitmap simultaneously without lock. If two
115 * users clear the same bit, one user will return remain bits,
116 * otherwise return 0.
117 */
118static unsigned long
119bitmap_clear_ll(unsigned long *map, unsigned long start, unsigned long nr)
120{
121 unsigned long *p = map + BIT_WORD(start);
122 const unsigned long 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) {
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 */
151struct 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}
166EXPORT_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 */
182int 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 unsigned long nbits = size >> pool->min_alloc_order;
187 unsigned long 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}
206EXPORT_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 */
215phys_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}
231EXPORT_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 */
240void 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 unsigned long 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_first_bit(chunk->bits, end_bit);
253 BUG_ON(bit < end_bit);
254
255 vfree(chunk);
256 }
257 kfree_const(pool->name);
258 kfree(pool);
259}
260EXPORT_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 */
275unsigned 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 unsigned long 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;
301retry:
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}
324EXPORT_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 */
339void *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}
343EXPORT_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 */
360void *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}
377EXPORT_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 */
393void *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}
401EXPORT_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 */
417void *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}
421EXPORT_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 */
438void *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}
448EXPORT_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 */
464void *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}
472EXPORT_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 */
485void 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 unsigned long 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}
518EXPORT_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 */
529void 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}
540EXPORT_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 */
551bool gen_pool_has_addr(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}
570EXPORT_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 */
578size_t gen_pool_avail(struct gen_pool *pool)
579{
580 struct gen_pool_chunk *chunk;
581 size_t avail = 0;
582
583 rcu_read_lock();
584 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
585 avail += atomic_long_read(&chunk->avail);
586 rcu_read_unlock();
587 return avail;
588}
589EXPORT_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 */
597size_t gen_pool_size(struct gen_pool *pool)
598{
599 struct gen_pool_chunk *chunk;
600 size_t size = 0;
601
602 rcu_read_lock();
603 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
604 size += chunk_size(chunk);
605 rcu_read_unlock();
606 return size;
607}
608EXPORT_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 */
620void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, void *data)
621{
622 rcu_read_lock();
623
624 pool->algo = algo;
625 if (!pool->algo)
626 pool->algo = gen_pool_first_fit;
627
628 pool->data = data;
629
630 rcu_read_unlock();
631}
632EXPORT_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 * @start_addr: not used in this function
644 */
645unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
646 unsigned long start, unsigned int nr, void *data,
647 struct gen_pool *pool, unsigned long start_addr)
648{
649 return bitmap_find_next_zero_area(map, size, start, nr, 0);
650}
651EXPORT_SYMBOL(gen_pool_first_fit);
652
653/**
654 * gen_pool_first_fit_align - find the first available region
655 * of memory matching the size requirement (alignment constraint)
656 * @map: The address to base the search on
657 * @size: The bitmap size in bits
658 * @start: The bitnumber to start searching at
659 * @nr: The number of zeroed bits we're looking for
660 * @data: data for alignment
661 * @pool: pool to get order from
662 * @start_addr: start addr of alloction chunk
663 */
664unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size,
665 unsigned long start, unsigned int nr, void *data,
666 struct gen_pool *pool, unsigned long start_addr)
667{
668 struct genpool_data_align *alignment;
669 unsigned long align_mask, align_off;
670 int order;
671
672 alignment = data;
673 order = pool->min_alloc_order;
674 align_mask = ((alignment->align + (1UL << order) - 1) >> order) - 1;
675 align_off = (start_addr & (alignment->align - 1)) >> order;
676
677 return bitmap_find_next_zero_area_off(map, size, start, nr,
678 align_mask, align_off);
679}
680EXPORT_SYMBOL(gen_pool_first_fit_align);
681
682/**
683 * gen_pool_fixed_alloc - reserve a specific region
684 * @map: The address to base the search on
685 * @size: The bitmap size in bits
686 * @start: The bitnumber to start searching at
687 * @nr: The number of zeroed bits we're looking for
688 * @data: data for alignment
689 * @pool: pool to get order from
690 * @start_addr: not used in this function
691 */
692unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size,
693 unsigned long start, unsigned int nr, void *data,
694 struct gen_pool *pool, unsigned long start_addr)
695{
696 struct genpool_data_fixed *fixed_data;
697 int order;
698 unsigned long offset_bit;
699 unsigned long start_bit;
700
701 fixed_data = data;
702 order = pool->min_alloc_order;
703 offset_bit = fixed_data->offset >> order;
704 if (WARN_ON(fixed_data->offset & ((1UL << order) - 1)))
705 return size;
706
707 start_bit = bitmap_find_next_zero_area(map, size,
708 start + offset_bit, nr, 0);
709 if (start_bit != offset_bit)
710 start_bit = size;
711 return start_bit;
712}
713EXPORT_SYMBOL(gen_pool_fixed_alloc);
714
715/**
716 * gen_pool_first_fit_order_align - find the first available region
717 * of memory matching the size requirement. The region will be aligned
718 * to the order of the size specified.
719 * @map: The address to base the search on
720 * @size: The bitmap size in bits
721 * @start: The bitnumber to start searching at
722 * @nr: The number of zeroed bits we're looking for
723 * @data: additional data - unused
724 * @pool: pool to find the fit region memory from
725 * @start_addr: not used in this function
726 */
727unsigned long gen_pool_first_fit_order_align(unsigned long *map,
728 unsigned long size, unsigned long start,
729 unsigned int nr, void *data, struct gen_pool *pool,
730 unsigned long start_addr)
731{
732 unsigned long align_mask = roundup_pow_of_two(nr) - 1;
733
734 return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
735}
736EXPORT_SYMBOL(gen_pool_first_fit_order_align);
737
738/**
739 * gen_pool_best_fit - find the best fitting region of memory
740 * matching the size requirement (no alignment constraint)
741 * @map: The address to base the search on
742 * @size: The bitmap size in bits
743 * @start: The bitnumber to start searching at
744 * @nr: The number of zeroed bits we're looking for
745 * @data: additional data - unused
746 * @pool: pool to find the fit region memory from
747 * @start_addr: not used in this function
748 *
749 * Iterate over the bitmap to find the smallest free region
750 * which we can allocate the memory.
751 */
752unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
753 unsigned long start, unsigned int nr, void *data,
754 struct gen_pool *pool, unsigned long start_addr)
755{
756 unsigned long start_bit = size;
757 unsigned long len = size + 1;
758 unsigned long index;
759
760 index = bitmap_find_next_zero_area(map, size, start, nr, 0);
761
762 while (index < size) {
763 unsigned long next_bit = find_next_bit(map, size, index + nr);
764 if ((next_bit - index) < len) {
765 len = next_bit - index;
766 start_bit = index;
767 if (len == nr)
768 return start_bit;
769 }
770 index = bitmap_find_next_zero_area(map, size,
771 next_bit + 1, nr, 0);
772 }
773
774 return start_bit;
775}
776EXPORT_SYMBOL(gen_pool_best_fit);
777
778static void devm_gen_pool_release(struct device *dev, void *res)
779{
780 gen_pool_destroy(*(struct gen_pool **)res);
781}
782
783static int devm_gen_pool_match(struct device *dev, void *res, void *data)
784{
785 struct gen_pool **p = res;
786
787 /* NULL data matches only a pool without an assigned name */
788 if (!data && !(*p)->name)
789 return 1;
790
791 if (!data || !(*p)->name)
792 return 0;
793
794 return !strcmp((*p)->name, data);
795}
796
797/**
798 * gen_pool_get - Obtain the gen_pool (if any) for a device
799 * @dev: device to retrieve the gen_pool from
800 * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
801 *
802 * Returns the gen_pool for the device if one is present, or NULL.
803 */
804struct gen_pool *gen_pool_get(struct device *dev, const char *name)
805{
806 struct gen_pool **p;
807
808 p = devres_find(dev, devm_gen_pool_release, devm_gen_pool_match,
809 (void *)name);
810 if (!p)
811 return NULL;
812 return *p;
813}
814EXPORT_SYMBOL_GPL(gen_pool_get);
815
816/**
817 * devm_gen_pool_create - managed gen_pool_create
818 * @dev: device that provides the gen_pool
819 * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
820 * @nid: node selector for allocated gen_pool, %NUMA_NO_NODE for all nodes
821 * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
822 *
823 * Create a new special memory pool that can be used to manage special purpose
824 * memory not managed by the regular kmalloc/kfree interface. The pool will be
825 * automatically destroyed by the device management code.
826 */
827struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order,
828 int nid, const char *name)
829{
830 struct gen_pool **ptr, *pool;
831 const char *pool_name = NULL;
832
833 /* Check that genpool to be created is uniquely addressed on device */
834 if (gen_pool_get(dev, name))
835 return ERR_PTR(-EINVAL);
836
837 if (name) {
838 pool_name = kstrdup_const(name, GFP_KERNEL);
839 if (!pool_name)
840 return ERR_PTR(-ENOMEM);
841 }
842
843 ptr = devres_alloc(devm_gen_pool_release, sizeof(*ptr), GFP_KERNEL);
844 if (!ptr)
845 goto free_pool_name;
846
847 pool = gen_pool_create(min_alloc_order, nid);
848 if (!pool)
849 goto free_devres;
850
851 *ptr = pool;
852 pool->name = pool_name;
853 devres_add(dev, ptr);
854
855 return pool;
856
857free_devres:
858 devres_free(ptr);
859free_pool_name:
860 kfree_const(pool_name);
861
862 return ERR_PTR(-ENOMEM);
863}
864EXPORT_SYMBOL(devm_gen_pool_create);
865
866#ifdef CONFIG_OF
867/**
868 * of_gen_pool_get - find a pool by phandle property
869 * @np: device node
870 * @propname: property name containing phandle(s)
871 * @index: index into the phandle array
872 *
873 * Returns the pool that contains the chunk starting at the physical
874 * address of the device tree node pointed at by the phandle property,
875 * or NULL if not found.
876 */
877struct gen_pool *of_gen_pool_get(struct device_node *np,
878 const char *propname, int index)
879{
880 struct platform_device *pdev;
881 struct device_node *np_pool, *parent;
882 const char *name = NULL;
883 struct gen_pool *pool = NULL;
884
885 np_pool = of_parse_phandle(np, propname, index);
886 if (!np_pool)
887 return NULL;
888
889 pdev = of_find_device_by_node(np_pool);
890 if (!pdev) {
891 /* Check if named gen_pool is created by parent node device */
892 parent = of_get_parent(np_pool);
893 pdev = of_find_device_by_node(parent);
894 of_node_put(parent);
895
896 of_property_read_string(np_pool, "label", &name);
897 if (!name)
898 name = np_pool->name;
899 }
900 if (pdev)
901 pool = gen_pool_get(&pdev->dev, name);
902 of_node_put(np_pool);
903
904 return pool;
905}
906EXPORT_SYMBOL_GPL(of_gen_pool_get);
907#endif /* CONFIG_OF */