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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 <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
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 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
58static 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 */
84static unsigned long
85bitmap_set_ll(unsigned long *map, unsigned long start, unsigned long nr)
86{
87 unsigned long *p = map + BIT_WORD(start);
88 const unsigned long size = start + nr;
89 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
90 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
91
92 while (nr >= bits_to_set) {
93 if (set_bits_ll(p, mask_to_set))
94 return nr;
95 nr -= bits_to_set;
96 bits_to_set = BITS_PER_LONG;
97 mask_to_set = ~0UL;
98 p++;
99 }
100 if (nr) {
101 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
102 if (set_bits_ll(p, mask_to_set))
103 return nr;
104 }
105
106 return 0;
107}
108
109/*
110 * bitmap_clear_ll - clear the specified number of bits at the specified position
111 * @map: pointer to a bitmap
112 * @start: a bit position in @map
113 * @nr: number of bits to set
114 *
115 * Clear @nr bits start from @start in @map lock-lessly. Several users
116 * can set/clear the same bitmap simultaneously without lock. If two
117 * users clear the same bit, one user will return remain bits,
118 * otherwise return 0.
119 */
120static unsigned long
121bitmap_clear_ll(unsigned long *map, unsigned long start, unsigned long nr)
122{
123 unsigned long *p = map + BIT_WORD(start);
124 const unsigned long size = start + nr;
125 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
126 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
127
128 while (nr >= bits_to_clear) {
129 if (clear_bits_ll(p, mask_to_clear))
130 return nr;
131 nr -= bits_to_clear;
132 bits_to_clear = BITS_PER_LONG;
133 mask_to_clear = ~0UL;
134 p++;
135 }
136 if (nr) {
137 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
138 if (clear_bits_ll(p, mask_to_clear))
139 return nr;
140 }
141
142 return 0;
143}
144
145/**
146 * gen_pool_create - create a new special memory pool
147 * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
148 * @nid: node id of the node the pool structure should be allocated on, or -1
149 *
150 * Create a new special memory pool that can be used to manage special purpose
151 * memory not managed by the regular kmalloc/kfree interface.
152 */
153struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
154{
155 struct gen_pool *pool;
156
157 pool = kmalloc_node(sizeof(struct gen_pool), GFP_KERNEL, nid);
158 if (pool != NULL) {
159 spin_lock_init(&pool->lock);
160 INIT_LIST_HEAD(&pool->chunks);
161 pool->min_alloc_order = min_alloc_order;
162 pool->algo = gen_pool_first_fit;
163 pool->data = NULL;
164 pool->name = NULL;
165 }
166 return pool;
167}
168EXPORT_SYMBOL(gen_pool_create);
169
170/**
171 * gen_pool_add_owner- add a new chunk of special memory to the pool
172 * @pool: pool to add new memory chunk to
173 * @virt: virtual starting address of memory chunk to add to pool
174 * @phys: physical starting address of memory chunk to add to pool
175 * @size: size in bytes of the memory chunk to add to pool
176 * @nid: node id of the node the chunk structure and bitmap should be
177 * allocated on, or -1
178 * @owner: private data the publisher would like to recall at alloc time
179 *
180 * Add a new chunk of special memory to the specified pool.
181 *
182 * Returns 0 on success or a -ve errno on failure.
183 */
184int gen_pool_add_owner(struct gen_pool *pool, unsigned long virt, phys_addr_t phys,
185 size_t size, int nid, void *owner)
186{
187 struct gen_pool_chunk *chunk;
188 unsigned long nbits = size >> pool->min_alloc_order;
189 unsigned long nbytes = sizeof(struct gen_pool_chunk) +
190 BITS_TO_LONGS(nbits) * sizeof(long);
191
192 chunk = vzalloc_node(nbytes, nid);
193 if (unlikely(chunk == NULL))
194 return -ENOMEM;
195
196 chunk->phys_addr = phys;
197 chunk->start_addr = virt;
198 chunk->end_addr = virt + size - 1;
199 chunk->owner = owner;
200 atomic_long_set(&chunk->avail, size);
201
202 spin_lock(&pool->lock);
203 list_add_rcu(&chunk->next_chunk, &pool->chunks);
204 spin_unlock(&pool->lock);
205
206 return 0;
207}
208EXPORT_SYMBOL(gen_pool_add_owner);
209
210/**
211 * gen_pool_virt_to_phys - return the physical address of memory
212 * @pool: pool to allocate from
213 * @addr: starting address of memory
214 *
215 * Returns the physical address on success, or -1 on error.
216 */
217phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long addr)
218{
219 struct gen_pool_chunk *chunk;
220 phys_addr_t paddr = -1;
221
222 rcu_read_lock();
223 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
224 if (addr >= chunk->start_addr && addr <= chunk->end_addr) {
225 paddr = chunk->phys_addr + (addr - chunk->start_addr);
226 break;
227 }
228 }
229 rcu_read_unlock();
230
231 return paddr;
232}
233EXPORT_SYMBOL(gen_pool_virt_to_phys);
234
235/**
236 * gen_pool_destroy - destroy a special memory pool
237 * @pool: pool to destroy
238 *
239 * Destroy the specified special memory pool. Verifies that there are no
240 * outstanding allocations.
241 */
242void gen_pool_destroy(struct gen_pool *pool)
243{
244 struct list_head *_chunk, *_next_chunk;
245 struct gen_pool_chunk *chunk;
246 int order = pool->min_alloc_order;
247 unsigned long bit, end_bit;
248
249 list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
250 chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
251 list_del(&chunk->next_chunk);
252
253 end_bit = chunk_size(chunk) >> order;
254 bit = find_next_bit(chunk->bits, end_bit, 0);
255 BUG_ON(bit < end_bit);
256
257 vfree(chunk);
258 }
259 kfree_const(pool->name);
260 kfree(pool);
261}
262EXPORT_SYMBOL(gen_pool_destroy);
263
264/**
265 * gen_pool_alloc_algo_owner - allocate special memory from the pool
266 * @pool: pool to allocate from
267 * @size: number of bytes to allocate from the pool
268 * @algo: algorithm passed from caller
269 * @data: data passed to algorithm
270 * @owner: optionally retrieve the chunk owner
271 *
272 * Allocate the requested number of bytes from the specified pool.
273 * Uses the pool allocation function (with first-fit algorithm by default).
274 * Can not be used in NMI handler on architectures without
275 * NMI-safe cmpxchg implementation.
276 */
277unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size,
278 genpool_algo_t algo, void *data, void **owner)
279{
280 struct gen_pool_chunk *chunk;
281 unsigned long addr = 0;
282 int order = pool->min_alloc_order;
283 unsigned long nbits, start_bit, end_bit, remain;
284
285#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
286 BUG_ON(in_nmi());
287#endif
288
289 if (owner)
290 *owner = NULL;
291
292 if (size == 0)
293 return 0;
294
295 nbits = (size + (1UL << order) - 1) >> order;
296 rcu_read_lock();
297 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
298 if (size > atomic_long_read(&chunk->avail))
299 continue;
300
301 start_bit = 0;
302 end_bit = chunk_size(chunk) >> order;
303retry:
304 start_bit = algo(chunk->bits, end_bit, start_bit,
305 nbits, data, pool, chunk->start_addr);
306 if (start_bit >= end_bit)
307 continue;
308 remain = bitmap_set_ll(chunk->bits, start_bit, nbits);
309 if (remain) {
310 remain = bitmap_clear_ll(chunk->bits, start_bit,
311 nbits - remain);
312 BUG_ON(remain);
313 goto retry;
314 }
315
316 addr = chunk->start_addr + ((unsigned long)start_bit << order);
317 size = nbits << order;
318 atomic_long_sub(size, &chunk->avail);
319 if (owner)
320 *owner = chunk->owner;
321 break;
322 }
323 rcu_read_unlock();
324 return addr;
325}
326EXPORT_SYMBOL(gen_pool_alloc_algo_owner);
327
328/**
329 * gen_pool_dma_alloc - allocate special memory from the pool for DMA usage
330 * @pool: pool to allocate from
331 * @size: number of bytes to allocate from the pool
332 * @dma: dma-view physical address return value. Use %NULL if unneeded.
333 *
334 * Allocate the requested number of bytes from the specified pool.
335 * Uses the pool allocation function (with first-fit algorithm by default).
336 * Can not be used in NMI handler on architectures without
337 * NMI-safe cmpxchg implementation.
338 *
339 * Return: virtual address of the allocated memory, or %NULL on failure
340 */
341void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
342{
343 return gen_pool_dma_alloc_algo(pool, size, dma, pool->algo, pool->data);
344}
345EXPORT_SYMBOL(gen_pool_dma_alloc);
346
347/**
348 * gen_pool_dma_alloc_algo - allocate special memory from the pool for DMA
349 * usage with the given pool algorithm
350 * @pool: pool to allocate from
351 * @size: number of bytes to allocate from the pool
352 * @dma: DMA-view physical address return value. Use %NULL if unneeded.
353 * @algo: algorithm passed from caller
354 * @data: data passed to algorithm
355 *
356 * Allocate the requested number of bytes from the specified pool. Uses the
357 * given pool allocation function. Can not be used in NMI handler on
358 * architectures without NMI-safe cmpxchg implementation.
359 *
360 * Return: virtual address of the allocated memory, or %NULL on failure
361 */
362void *gen_pool_dma_alloc_algo(struct gen_pool *pool, size_t size,
363 dma_addr_t *dma, genpool_algo_t algo, void *data)
364{
365 unsigned long vaddr;
366
367 if (!pool)
368 return NULL;
369
370 vaddr = gen_pool_alloc_algo(pool, size, algo, data);
371 if (!vaddr)
372 return NULL;
373
374 if (dma)
375 *dma = gen_pool_virt_to_phys(pool, vaddr);
376
377 return (void *)vaddr;
378}
379EXPORT_SYMBOL(gen_pool_dma_alloc_algo);
380
381/**
382 * gen_pool_dma_alloc_align - allocate special memory from the pool for DMA
383 * usage with the given alignment
384 * @pool: pool to allocate from
385 * @size: number of bytes to allocate from the pool
386 * @dma: DMA-view physical address return value. Use %NULL if unneeded.
387 * @align: alignment in bytes for starting address
388 *
389 * Allocate the requested number bytes from the specified pool, with the given
390 * alignment restriction. Can not be used in NMI handler on architectures
391 * without NMI-safe cmpxchg implementation.
392 *
393 * Return: virtual address of the allocated memory, or %NULL on failure
394 */
395void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size,
396 dma_addr_t *dma, int align)
397{
398 struct genpool_data_align data = { .align = align };
399
400 return gen_pool_dma_alloc_algo(pool, size, dma,
401 gen_pool_first_fit_align, &data);
402}
403EXPORT_SYMBOL(gen_pool_dma_alloc_align);
404
405/**
406 * gen_pool_dma_zalloc - allocate special zeroed memory from the pool for
407 * DMA usage
408 * @pool: pool to allocate from
409 * @size: number of bytes to allocate from the pool
410 * @dma: dma-view physical address return value. Use %NULL if unneeded.
411 *
412 * Allocate the requested number of zeroed bytes from the specified pool.
413 * Uses the pool allocation function (with first-fit algorithm by default).
414 * Can not be used in NMI handler on architectures without
415 * NMI-safe cmpxchg implementation.
416 *
417 * Return: virtual address of the allocated zeroed memory, or %NULL on failure
418 */
419void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
420{
421 return gen_pool_dma_zalloc_algo(pool, size, dma, pool->algo, pool->data);
422}
423EXPORT_SYMBOL(gen_pool_dma_zalloc);
424
425/**
426 * gen_pool_dma_zalloc_algo - allocate special zeroed memory from the pool for
427 * DMA usage with the given pool algorithm
428 * @pool: pool to allocate from
429 * @size: number of bytes to allocate from the pool
430 * @dma: DMA-view physical address return value. Use %NULL if unneeded.
431 * @algo: algorithm passed from caller
432 * @data: data passed to algorithm
433 *
434 * Allocate the requested number of zeroed bytes from the specified pool. Uses
435 * the given pool allocation function. Can not be used in NMI handler on
436 * architectures without NMI-safe cmpxchg implementation.
437 *
438 * Return: virtual address of the allocated zeroed memory, or %NULL on failure
439 */
440void *gen_pool_dma_zalloc_algo(struct gen_pool *pool, size_t size,
441 dma_addr_t *dma, genpool_algo_t algo, void *data)
442{
443 void *vaddr = gen_pool_dma_alloc_algo(pool, size, dma, algo, data);
444
445 if (vaddr)
446 memset(vaddr, 0, size);
447
448 return vaddr;
449}
450EXPORT_SYMBOL(gen_pool_dma_zalloc_algo);
451
452/**
453 * gen_pool_dma_zalloc_align - allocate special zeroed memory from the pool for
454 * DMA usage with the given alignment
455 * @pool: pool to allocate from
456 * @size: number of bytes to allocate from the pool
457 * @dma: DMA-view physical address return value. Use %NULL if unneeded.
458 * @align: alignment in bytes for starting address
459 *
460 * Allocate the requested number of zeroed bytes from the specified pool,
461 * with the given alignment restriction. Can not be used in NMI handler on
462 * architectures without NMI-safe cmpxchg implementation.
463 *
464 * Return: virtual address of the allocated zeroed memory, or %NULL on failure
465 */
466void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size,
467 dma_addr_t *dma, int align)
468{
469 struct genpool_data_align data = { .align = align };
470
471 return gen_pool_dma_zalloc_algo(pool, size, dma,
472 gen_pool_first_fit_align, &data);
473}
474EXPORT_SYMBOL(gen_pool_dma_zalloc_align);
475
476/**
477 * gen_pool_free_owner - free allocated special memory back to the pool
478 * @pool: pool to free to
479 * @addr: starting address of memory to free back to pool
480 * @size: size in bytes of memory to free
481 * @owner: private data stashed at gen_pool_add() time
482 *
483 * Free previously allocated special memory back to the specified
484 * pool. Can not be used in NMI handler on architectures without
485 * NMI-safe cmpxchg implementation.
486 */
487void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, size_t size,
488 void **owner)
489{
490 struct gen_pool_chunk *chunk;
491 int order = pool->min_alloc_order;
492 unsigned long start_bit, nbits, remain;
493
494#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
495 BUG_ON(in_nmi());
496#endif
497
498 if (owner)
499 *owner = NULL;
500
501 nbits = (size + (1UL << order) - 1) >> order;
502 rcu_read_lock();
503 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
504 if (addr >= chunk->start_addr && addr <= chunk->end_addr) {
505 BUG_ON(addr + size - 1 > chunk->end_addr);
506 start_bit = (addr - chunk->start_addr) >> order;
507 remain = bitmap_clear_ll(chunk->bits, start_bit, nbits);
508 BUG_ON(remain);
509 size = nbits << order;
510 atomic_long_add(size, &chunk->avail);
511 if (owner)
512 *owner = chunk->owner;
513 rcu_read_unlock();
514 return;
515 }
516 }
517 rcu_read_unlock();
518 BUG();
519}
520EXPORT_SYMBOL(gen_pool_free_owner);
521
522/**
523 * gen_pool_for_each_chunk - call func for every chunk of generic memory pool
524 * @pool: the generic memory pool
525 * @func: func to call
526 * @data: additional data used by @func
527 *
528 * Call @func for every chunk of generic memory pool. The @func is
529 * called with rcu_read_lock held.
530 */
531void gen_pool_for_each_chunk(struct gen_pool *pool,
532 void (*func)(struct gen_pool *pool, struct gen_pool_chunk *chunk, void *data),
533 void *data)
534{
535 struct gen_pool_chunk *chunk;
536
537 rcu_read_lock();
538 list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk)
539 func(pool, chunk, data);
540 rcu_read_unlock();
541}
542EXPORT_SYMBOL(gen_pool_for_each_chunk);
543
544/**
545 * gen_pool_has_addr - checks if an address falls within the range of a pool
546 * @pool: the generic memory pool
547 * @start: start address
548 * @size: size of the region
549 *
550 * Check if the range of addresses falls within the specified pool. Returns
551 * true if the entire range is contained in the pool and false otherwise.
552 */
553bool gen_pool_has_addr(struct gen_pool *pool, unsigned long start,
554 size_t size)
555{
556 bool found = false;
557 unsigned long end = start + size - 1;
558 struct gen_pool_chunk *chunk;
559
560 rcu_read_lock();
561 list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk) {
562 if (start >= chunk->start_addr && start <= chunk->end_addr) {
563 if (end <= chunk->end_addr) {
564 found = true;
565 break;
566 }
567 }
568 }
569 rcu_read_unlock();
570 return found;
571}
572EXPORT_SYMBOL(gen_pool_has_addr);
573
574/**
575 * gen_pool_avail - get available free space of the pool
576 * @pool: pool to get available free space
577 *
578 * Return available free space of the specified pool.
579 */
580size_t gen_pool_avail(struct gen_pool *pool)
581{
582 struct gen_pool_chunk *chunk;
583 size_t avail = 0;
584
585 rcu_read_lock();
586 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
587 avail += atomic_long_read(&chunk->avail);
588 rcu_read_unlock();
589 return avail;
590}
591EXPORT_SYMBOL_GPL(gen_pool_avail);
592
593/**
594 * gen_pool_size - get size in bytes of memory managed by the pool
595 * @pool: pool to get size
596 *
597 * Return size in bytes of memory managed by the pool.
598 */
599size_t gen_pool_size(struct gen_pool *pool)
600{
601 struct gen_pool_chunk *chunk;
602 size_t size = 0;
603
604 rcu_read_lock();
605 list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
606 size += chunk_size(chunk);
607 rcu_read_unlock();
608 return size;
609}
610EXPORT_SYMBOL_GPL(gen_pool_size);
611
612/**
613 * gen_pool_set_algo - set the allocation algorithm
614 * @pool: pool to change allocation algorithm
615 * @algo: custom algorithm function
616 * @data: additional data used by @algo
617 *
618 * Call @algo for each memory allocation in the pool.
619 * If @algo is NULL use gen_pool_first_fit as default
620 * memory allocation function.
621 */
622void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, void *data)
623{
624 rcu_read_lock();
625
626 pool->algo = algo;
627 if (!pool->algo)
628 pool->algo = gen_pool_first_fit;
629
630 pool->data = data;
631
632 rcu_read_unlock();
633}
634EXPORT_SYMBOL(gen_pool_set_algo);
635
636/**
637 * gen_pool_first_fit - find the first available region
638 * of memory matching the size requirement (no alignment constraint)
639 * @map: The address to base the search on
640 * @size: The bitmap size in bits
641 * @start: The bitnumber to start searching at
642 * @nr: The number of zeroed bits we're looking for
643 * @data: additional data - unused
644 * @pool: pool to find the fit region memory from
645 * @start_addr: not used in this function
646 */
647unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
648 unsigned long start, unsigned int nr, void *data,
649 struct gen_pool *pool, unsigned long start_addr)
650{
651 return bitmap_find_next_zero_area(map, size, start, nr, 0);
652}
653EXPORT_SYMBOL(gen_pool_first_fit);
654
655/**
656 * gen_pool_first_fit_align - find the first available region
657 * of memory matching the size requirement (alignment constraint)
658 * @map: The address to base the search on
659 * @size: The bitmap size in bits
660 * @start: The bitnumber to start searching at
661 * @nr: The number of zeroed bits we're looking for
662 * @data: data for alignment
663 * @pool: pool to get order from
664 * @start_addr: start addr of alloction chunk
665 */
666unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size,
667 unsigned long start, unsigned int nr, void *data,
668 struct gen_pool *pool, unsigned long start_addr)
669{
670 struct genpool_data_align *alignment;
671 unsigned long align_mask, align_off;
672 int order;
673
674 alignment = data;
675 order = pool->min_alloc_order;
676 align_mask = ((alignment->align + (1UL << order) - 1) >> order) - 1;
677 align_off = (start_addr & (alignment->align - 1)) >> order;
678
679 return bitmap_find_next_zero_area_off(map, size, start, nr,
680 align_mask, align_off);
681}
682EXPORT_SYMBOL(gen_pool_first_fit_align);
683
684/**
685 * gen_pool_fixed_alloc - reserve a specific region
686 * @map: The address to base the search on
687 * @size: The bitmap size in bits
688 * @start: The bitnumber to start searching at
689 * @nr: The number of zeroed bits we're looking for
690 * @data: data for alignment
691 * @pool: pool to get order from
692 * @start_addr: not used in this function
693 */
694unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size,
695 unsigned long start, unsigned int nr, void *data,
696 struct gen_pool *pool, unsigned long start_addr)
697{
698 struct genpool_data_fixed *fixed_data;
699 int order;
700 unsigned long offset_bit;
701 unsigned long start_bit;
702
703 fixed_data = data;
704 order = pool->min_alloc_order;
705 offset_bit = fixed_data->offset >> order;
706 if (WARN_ON(fixed_data->offset & ((1UL << order) - 1)))
707 return size;
708
709 start_bit = bitmap_find_next_zero_area(map, size,
710 start + offset_bit, nr, 0);
711 if (start_bit != offset_bit)
712 start_bit = size;
713 return start_bit;
714}
715EXPORT_SYMBOL(gen_pool_fixed_alloc);
716
717/**
718 * gen_pool_first_fit_order_align - find the first available region
719 * of memory matching the size requirement. The region will be aligned
720 * to the order of the size specified.
721 * @map: The address to base the search on
722 * @size: The bitmap size in bits
723 * @start: The bitnumber to start searching at
724 * @nr: The number of zeroed bits we're looking for
725 * @data: additional data - unused
726 * @pool: pool to find the fit region memory from
727 * @start_addr: not used in this function
728 */
729unsigned long gen_pool_first_fit_order_align(unsigned long *map,
730 unsigned long size, unsigned long start,
731 unsigned int nr, void *data, struct gen_pool *pool,
732 unsigned long start_addr)
733{
734 unsigned long align_mask = roundup_pow_of_two(nr) - 1;
735
736 return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
737}
738EXPORT_SYMBOL(gen_pool_first_fit_order_align);
739
740/**
741 * gen_pool_best_fit - find the best fitting region of memory
742 * matching the size requirement (no alignment constraint)
743 * @map: The address to base the search on
744 * @size: The bitmap size in bits
745 * @start: The bitnumber to start searching at
746 * @nr: The number of zeroed bits we're looking for
747 * @data: additional data - unused
748 * @pool: pool to find the fit region memory from
749 * @start_addr: not used in this function
750 *
751 * Iterate over the bitmap to find the smallest free region
752 * which we can allocate the memory.
753 */
754unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
755 unsigned long start, unsigned int nr, void *data,
756 struct gen_pool *pool, unsigned long start_addr)
757{
758 unsigned long start_bit = size;
759 unsigned long len = size + 1;
760 unsigned long index;
761
762 index = bitmap_find_next_zero_area(map, size, start, nr, 0);
763
764 while (index < size) {
765 unsigned long next_bit = find_next_bit(map, size, index + nr);
766 if ((next_bit - index) < len) {
767 len = next_bit - index;
768 start_bit = index;
769 if (len == nr)
770 return start_bit;
771 }
772 index = bitmap_find_next_zero_area(map, size,
773 next_bit + 1, nr, 0);
774 }
775
776 return start_bit;
777}
778EXPORT_SYMBOL(gen_pool_best_fit);
779
780static void devm_gen_pool_release(struct device *dev, void *res)
781{
782 gen_pool_destroy(*(struct gen_pool **)res);
783}
784
785static int devm_gen_pool_match(struct device *dev, void *res, void *data)
786{
787 struct gen_pool **p = res;
788
789 /* NULL data matches only a pool without an assigned name */
790 if (!data && !(*p)->name)
791 return 1;
792
793 if (!data || !(*p)->name)
794 return 0;
795
796 return !strcmp((*p)->name, data);
797}
798
799/**
800 * gen_pool_get - Obtain the gen_pool (if any) for a device
801 * @dev: device to retrieve the gen_pool from
802 * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
803 *
804 * Returns the gen_pool for the device if one is present, or NULL.
805 */
806struct gen_pool *gen_pool_get(struct device *dev, const char *name)
807{
808 struct gen_pool **p;
809
810 p = devres_find(dev, devm_gen_pool_release, devm_gen_pool_match,
811 (void *)name);
812 if (!p)
813 return NULL;
814 return *p;
815}
816EXPORT_SYMBOL_GPL(gen_pool_get);
817
818/**
819 * devm_gen_pool_create - managed gen_pool_create
820 * @dev: device that provides the gen_pool
821 * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
822 * @nid: node selector for allocated gen_pool, %NUMA_NO_NODE for all nodes
823 * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
824 *
825 * Create a new special memory pool that can be used to manage special purpose
826 * memory not managed by the regular kmalloc/kfree interface. The pool will be
827 * automatically destroyed by the device management code.
828 */
829struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order,
830 int nid, const char *name)
831{
832 struct gen_pool **ptr, *pool;
833 const char *pool_name = NULL;
834
835 /* Check that genpool to be created is uniquely addressed on device */
836 if (gen_pool_get(dev, name))
837 return ERR_PTR(-EINVAL);
838
839 if (name) {
840 pool_name = kstrdup_const(name, GFP_KERNEL);
841 if (!pool_name)
842 return ERR_PTR(-ENOMEM);
843 }
844
845 ptr = devres_alloc(devm_gen_pool_release, sizeof(*ptr), GFP_KERNEL);
846 if (!ptr)
847 goto free_pool_name;
848
849 pool = gen_pool_create(min_alloc_order, nid);
850 if (!pool)
851 goto free_devres;
852
853 *ptr = pool;
854 pool->name = pool_name;
855 devres_add(dev, ptr);
856
857 return pool;
858
859free_devres:
860 devres_free(ptr);
861free_pool_name:
862 kfree_const(pool_name);
863
864 return ERR_PTR(-ENOMEM);
865}
866EXPORT_SYMBOL(devm_gen_pool_create);
867
868#ifdef CONFIG_OF
869/**
870 * of_gen_pool_get - find a pool by phandle property
871 * @np: device node
872 * @propname: property name containing phandle(s)
873 * @index: index into the phandle array
874 *
875 * Returns the pool that contains the chunk starting at the physical
876 * address of the device tree node pointed at by the phandle property,
877 * or NULL if not found.
878 */
879struct gen_pool *of_gen_pool_get(struct device_node *np,
880 const char *propname, int index)
881{
882 struct platform_device *pdev;
883 struct device_node *np_pool, *parent;
884 const char *name = NULL;
885 struct gen_pool *pool = NULL;
886
887 np_pool = of_parse_phandle(np, propname, index);
888 if (!np_pool)
889 return NULL;
890
891 pdev = of_find_device_by_node(np_pool);
892 if (!pdev) {
893 /* Check if named gen_pool is created by parent node device */
894 parent = of_get_parent(np_pool);
895 pdev = of_find_device_by_node(parent);
896 of_node_put(parent);
897
898 of_property_read_string(np_pool, "label", &name);
899 if (!name)
900 name = np_pool->name;
901 }
902 if (pdev)
903 pool = gen_pool_get(&pdev->dev, name);
904 of_node_put(np_pool);
905
906 return pool;
907}
908EXPORT_SYMBOL_GPL(of_gen_pool_get);
909#endif /* CONFIG_OF */
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
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 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
58static 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 */
84static 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 */
119static 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 */
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 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}
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 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}
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 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;
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 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}
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 */
644unsigned 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 return bitmap_find_next_zero_area(map, size, start, nr, 0);
649}
650EXPORT_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 */
662unsigned 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 struct genpool_data_align *alignment;
667 unsigned long align_mask, align_off;
668 int order;
669
670 alignment = data;
671 order = pool->min_alloc_order;
672 align_mask = ((alignment->align + (1UL << order) - 1) >> order) - 1;
673 align_off = (start_addr & (alignment->align - 1)) >> order;
674
675 return bitmap_find_next_zero_area_off(map, size, start, nr,
676 align_mask, align_off);
677}
678EXPORT_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 */
689unsigned 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 struct genpool_data_fixed *fixed_data;
694 int order;
695 unsigned long offset_bit;
696 unsigned long start_bit;
697
698 fixed_data = data;
699 order = pool->min_alloc_order;
700 offset_bit = fixed_data->offset >> order;
701 if (WARN_ON(fixed_data->offset & ((1UL << order) - 1)))
702 return size;
703
704 start_bit = bitmap_find_next_zero_area(map, size,
705 start + offset_bit, nr, 0);
706 if (start_bit != offset_bit)
707 start_bit = size;
708 return start_bit;
709}
710EXPORT_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 */
723unsigned 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 unsigned long align_mask = roundup_pow_of_two(nr) - 1;
729
730 return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
731}
732EXPORT_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 */
747unsigned 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 unsigned long start_bit = size;
752 unsigned long len = size + 1;
753 unsigned long index;
754
755 index = bitmap_find_next_zero_area(map, size, start, nr, 0);
756
757 while (index < size) {
758 int next_bit = find_next_bit(map, size, index + nr);
759 if ((next_bit - index) < len) {
760 len = next_bit - index;
761 start_bit = index;
762 if (len == nr)
763 return start_bit;
764 }
765 index = bitmap_find_next_zero_area(map, size,
766 next_bit + 1, nr, 0);
767 }
768
769 return start_bit;
770}
771EXPORT_SYMBOL(gen_pool_best_fit);
772
773static void devm_gen_pool_release(struct device *dev, void *res)
774{
775 gen_pool_destroy(*(struct gen_pool **)res);
776}
777
778static int devm_gen_pool_match(struct device *dev, void *res, void *data)
779{
780 struct gen_pool **p = res;
781
782 /* NULL data matches only a pool without an assigned name */
783 if (!data && !(*p)->name)
784 return 1;
785
786 if (!data || !(*p)->name)
787 return 0;
788
789 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 */
799struct gen_pool *gen_pool_get(struct device *dev, const char *name)
800{
801 struct gen_pool **p;
802
803 p = devres_find(dev, devm_gen_pool_release, devm_gen_pool_match,
804 (void *)name);
805 if (!p)
806 return NULL;
807 return *p;
808}
809EXPORT_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 */
822struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order,
823 int nid, const char *name)
824{
825 struct gen_pool **ptr, *pool;
826 const char *pool_name = NULL;
827
828 /* Check that genpool to be created is uniquely addressed on device */
829 if (gen_pool_get(dev, name))
830 return ERR_PTR(-EINVAL);
831
832 if (name) {
833 pool_name = kstrdup_const(name, GFP_KERNEL);
834 if (!pool_name)
835 return ERR_PTR(-ENOMEM);
836 }
837
838 ptr = devres_alloc(devm_gen_pool_release, sizeof(*ptr), GFP_KERNEL);
839 if (!ptr)
840 goto free_pool_name;
841
842 pool = gen_pool_create(min_alloc_order, nid);
843 if (!pool)
844 goto free_devres;
845
846 *ptr = pool;
847 pool->name = pool_name;
848 devres_add(dev, ptr);
849
850 return pool;
851
852free_devres:
853 devres_free(ptr);
854free_pool_name:
855 kfree_const(pool_name);
856
857 return ERR_PTR(-ENOMEM);
858}
859EXPORT_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 */
872struct 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}
901EXPORT_SYMBOL_GPL(of_gen_pool_get);
902#endif /* CONFIG_OF */