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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Basic general purpose allocator for managing special purpose4 * memory, for example, memory that is not managed by the regular5 * kmalloc/kfree interface. Uses for this includes on-device special6 * memory, uncached memory etc.7 *8 * It is safe to use the allocator in NMI handlers and other special9 * unblockable contexts that could otherwise deadlock on locks. This10 * is implemented by using atomic operations and retries on any11 * conflicts. The disadvantage is that there may be livelocks in12 * extreme cases. For better scalability, one allocator can be used13 * for each CPU.14 *15 * The lockless operation only works if there is enough memory16 * available. If new memory is added to the pool a lock has to be17 * still taken. So any user relying on locklessness has to ensure18 * 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 the23 * allocator in NMI handler should depend on24 * 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.h>36#include <linux/of_platform.h>37#include <linux/platform_device.h>38#include <linux/vmalloc.h>39 40static inline size_t chunk_size(const struct gen_pool_chunk *chunk)41{42 return chunk->end_addr - chunk->start_addr + 1;43}44 45static inline int46set_bits_ll(unsigned long *addr, unsigned long mask_to_set)47{48 unsigned long val = READ_ONCE(*addr);49 50 do {51 if (val & mask_to_set)52 return -EBUSY;53 cpu_relax();54 } while (!try_cmpxchg(addr, &val, val | mask_to_set));55 56 return 0;57}58 59static inline int60clear_bits_ll(unsigned long *addr, unsigned long mask_to_clear)61{62 unsigned long val = READ_ONCE(*addr);63 64 do {65 if ((val & mask_to_clear) != mask_to_clear)66 return -EBUSY;67 cpu_relax();68 } while (!try_cmpxchg(addr, &val, val & ~mask_to_clear));69 70 return 0;71}72 73/*74 * bitmap_set_ll - set the specified number of bits at the specified position75 * @map: pointer to a bitmap76 * @start: a bit position in @map77 * @nr: number of bits to set78 *79 * Set @nr bits start from @start in @map lock-lessly. Several users80 * can set/clear the same bitmap simultaneously without lock. If two81 * users set the same bit, one user will return remain bits, otherwise82 * return 0.83 */84static unsigned long85bitmap_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 position111 * @map: pointer to a bitmap112 * @start: a bit position in @map113 * @nr: number of bits to set114 *115 * Clear @nr bits start from @start in @map lock-lessly. Several users116 * can set/clear the same bitmap simultaneously without lock. If two117 * users clear the same bit, one user will return remain bits,118 * otherwise return 0.119 */120static unsigned long121bitmap_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 pool147 * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents148 * @nid: node id of the node the pool structure should be allocated on, or -1149 *150 * Create a new special memory pool that can be used to manage special purpose151 * 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 pool172 * @pool: pool to add new memory chunk to173 * @virt: virtual starting address of memory chunk to add to pool174 * @phys: physical starting address of memory chunk to add to pool175 * @size: size in bytes of the memory chunk to add to pool176 * @nid: node id of the node the chunk structure and bitmap should be177 * allocated on, or -1178 * @owner: private data the publisher would like to recall at alloc time179 *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 memory212 * @pool: pool to allocate from213 * @addr: starting address of memory214 *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 pool237 * @pool: pool to destroy238 *239 * Destroy the specified special memory pool. Verifies that there are no240 * 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_first_bit(chunk->bits, end_bit);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 pool266 * @pool: pool to allocate from267 * @size: number of bytes to allocate from the pool268 * @algo: algorithm passed from caller269 * @data: data passed to algorithm270 * @owner: optionally retrieve the chunk owner271 *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 without275 * 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_CMPXCHG286 BUG_ON(in_nmi());287#endif288 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 usage330 * @pool: pool to allocate from331 * @size: number of bytes to allocate from the pool332 * @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 without337 * NMI-safe cmpxchg implementation.338 *339 * Return: virtual address of the allocated memory, or %NULL on failure340 */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 DMA349 * usage with the given pool algorithm350 * @pool: pool to allocate from351 * @size: number of bytes to allocate from the pool352 * @dma: DMA-view physical address return value. Use %NULL if unneeded.353 * @algo: algorithm passed from caller354 * @data: data passed to algorithm355 *356 * Allocate the requested number of bytes from the specified pool. Uses the357 * given pool allocation function. Can not be used in NMI handler on358 * architectures without NMI-safe cmpxchg implementation.359 *360 * Return: virtual address of the allocated memory, or %NULL on failure361 */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 DMA383 * usage with the given alignment384 * @pool: pool to allocate from385 * @size: number of bytes to allocate from the pool386 * @dma: DMA-view physical address return value. Use %NULL if unneeded.387 * @align: alignment in bytes for starting address388 *389 * Allocate the requested number bytes from the specified pool, with the given390 * alignment restriction. Can not be used in NMI handler on architectures391 * without NMI-safe cmpxchg implementation.392 *393 * Return: virtual address of the allocated memory, or %NULL on failure394 */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 for407 * DMA usage408 * @pool: pool to allocate from409 * @size: number of bytes to allocate from the pool410 * @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 without415 * NMI-safe cmpxchg implementation.416 *417 * Return: virtual address of the allocated zeroed memory, or %NULL on failure418 */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 for427 * DMA usage with the given pool algorithm428 * @pool: pool to allocate from429 * @size: number of bytes to allocate from the pool430 * @dma: DMA-view physical address return value. Use %NULL if unneeded.431 * @algo: algorithm passed from caller432 * @data: data passed to algorithm433 *434 * Allocate the requested number of zeroed bytes from the specified pool. Uses435 * the given pool allocation function. Can not be used in NMI handler on436 * architectures without NMI-safe cmpxchg implementation.437 *438 * Return: virtual address of the allocated zeroed memory, or %NULL on failure439 */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 for454 * DMA usage with the given alignment455 * @pool: pool to allocate from456 * @size: number of bytes to allocate from the pool457 * @dma: DMA-view physical address return value. Use %NULL if unneeded.458 * @align: alignment in bytes for starting address459 *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 on462 * architectures without NMI-safe cmpxchg implementation.463 *464 * Return: virtual address of the allocated zeroed memory, or %NULL on failure465 */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 pool478 * @pool: pool to free to479 * @addr: starting address of memory to free back to pool480 * @size: size in bytes of memory to free481 * @owner: private data stashed at gen_pool_add() time482 *483 * Free previously allocated special memory back to the specified484 * pool. Can not be used in NMI handler on architectures without485 * 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_CMPXCHG495 BUG_ON(in_nmi());496#endif497 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 pool524 * @pool: the generic memory pool525 * @func: func to call526 * @data: additional data used by @func527 *528 * Call @func for every chunk of generic memory pool. The @func is529 * 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 pool546 * @pool: the generic memory pool547 * @start: start address548 * @size: size of the region549 *550 * Check if the range of addresses falls within the specified pool. Returns551 * 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 pool576 * @pool: pool to get available free space577 *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 pool595 * @pool: pool to get size596 *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 algorithm614 * @pool: pool to change allocation algorithm615 * @algo: custom algorithm function616 * @data: additional data used by @algo617 *618 * Call @algo for each memory allocation in the pool.619 * If @algo is NULL use gen_pool_first_fit as default620 * 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 region638 * of memory matching the size requirement (no alignment constraint)639 * @map: The address to base the search on640 * @size: The bitmap size in bits641 * @start: The bitnumber to start searching at642 * @nr: The number of zeroed bits we're looking for643 * @data: additional data - unused644 * @pool: pool to find the fit region memory from645 * @start_addr: not used in this function646 */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 region657 * of memory matching the size requirement (alignment constraint)658 * @map: The address to base the search on659 * @size: The bitmap size in bits660 * @start: The bitnumber to start searching at661 * @nr: The number of zeroed bits we're looking for662 * @data: data for alignment663 * @pool: pool to get order from664 * @start_addr: start addr of alloction chunk665 */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 region686 * @map: The address to base the search on687 * @size: The bitmap size in bits688 * @start: The bitnumber to start searching at689 * @nr: The number of zeroed bits we're looking for690 * @data: data for alignment691 * @pool: pool to get order from692 * @start_addr: not used in this function693 */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 region719 * of memory matching the size requirement. The region will be aligned720 * to the order of the size specified.721 * @map: The address to base the search on722 * @size: The bitmap size in bits723 * @start: The bitnumber to start searching at724 * @nr: The number of zeroed bits we're looking for725 * @data: additional data - unused726 * @pool: pool to find the fit region memory from727 * @start_addr: not used in this function728 */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 memory742 * matching the size requirement (no alignment constraint)743 * @map: The address to base the search on744 * @size: The bitmap size in bits745 * @start: The bitnumber to start searching at746 * @nr: The number of zeroed bits we're looking for747 * @data: additional data - unused748 * @pool: pool to find the fit region memory from749 * @start_addr: not used in this function750 *751 * Iterate over the bitmap to find the smallest free region752 * 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 device801 * @dev: device to retrieve the gen_pool from802 * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device803 *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_create820 * @dev: device that provides the gen_pool821 * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents822 * @nid: node selector for allocated gen_pool, %NUMA_NO_NODE for all nodes823 * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device824 *825 * Create a new special memory pool that can be used to manage special purpose826 * memory not managed by the regular kmalloc/kfree interface. The pool will be827 * 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_OF869/**870 * of_gen_pool_get - find a pool by phandle property871 * @np: device node872 * @propname: property name containing phandle(s)873 * @index: index into the phandle array874 *875 * Returns the pool that contains the chunk starting at the physical876 * 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 = of_node_full_name(np_pool);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 */910