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.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 int 46set_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 int 60clear_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 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_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 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 = 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