Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Contiguous Memory Allocator for DMA mapping framework |
| 3 | * Copyright (c) 2010-2011 by Samsung Electronics. |
| 4 | * Written by: |
| 5 | * Marek Szyprowski <m.szyprowski@samsung.com> |
| 6 | * Michal Nazarewicz <mina86@mina86.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of the |
| 11 | * License or (at your optional) any later version of the license. |
| 12 | */ |
| 13 | |
| 14 | #define pr_fmt(fmt) "cma: " fmt |
| 15 | |
| 16 | #ifdef CONFIG_CMA_DEBUG |
| 17 | #ifndef DEBUG |
| 18 | # define DEBUG |
| 19 | #endif |
| 20 | #endif |
| 21 | |
| 22 | #include <asm/page.h> |
| 23 | #include <asm/dma-contiguous.h> |
| 24 | |
| 25 | #include <linux/memblock.h> |
| 26 | #include <linux/err.h> |
| 27 | #include <linux/mm.h> |
| 28 | #include <linux/mutex.h> |
| 29 | #include <linux/page-isolation.h> |
| 30 | #include <linux/slab.h> |
| 31 | #include <linux/swap.h> |
| 32 | #include <linux/mm_types.h> |
| 33 | #include <linux/dma-contiguous.h> |
Liam Mark | cc2d4bd | 2013-01-16 10:14:40 -0800 | [diff] [blame] | 34 | #include <trace/events/kmem.h> |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 35 | |
| 36 | #ifndef SZ_1M |
| 37 | #define SZ_1M (1 << 20) |
| 38 | #endif |
| 39 | |
| 40 | struct cma { |
| 41 | unsigned long base_pfn; |
| 42 | unsigned long count; |
| 43 | unsigned long *bitmap; |
| 44 | }; |
| 45 | |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 46 | static DEFINE_MUTEX(cma_mutex); |
| 47 | |
| 48 | struct cma *dma_contiguous_def_area; |
| 49 | phys_addr_t dma_contiguous_def_base; |
| 50 | |
| 51 | static struct cma_area { |
| 52 | phys_addr_t base; |
| 53 | unsigned long size; |
| 54 | struct cma *cma; |
| 55 | } cma_areas[MAX_CMA_AREAS] __initdata; |
| 56 | static unsigned cma_area_count __initdata; |
| 57 | |
| 58 | |
| 59 | static struct cma_map { |
| 60 | phys_addr_t base; |
| 61 | struct device *dev; |
| 62 | } cma_maps[MAX_CMA_AREAS] __initdata; |
| 63 | static unsigned cma_map_count __initdata; |
| 64 | |
| 65 | static struct cma *cma_get_area(phys_addr_t base) |
| 66 | { |
| 67 | int i; |
| 68 | for (i = 0; i < cma_area_count; i++) |
| 69 | if (cma_areas[i].base == base) |
| 70 | return cma_areas[i].cma; |
| 71 | return NULL; |
| 72 | } |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 73 | |
| 74 | #ifdef CONFIG_CMA_SIZE_MBYTES |
| 75 | #define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES |
| 76 | #else |
| 77 | #define CMA_SIZE_MBYTES 0 |
| 78 | #endif |
| 79 | |
| 80 | /* |
| 81 | * Default global CMA area size can be defined in kernel's .config. |
| 82 | * This is usefull mainly for distro maintainers to create a kernel |
| 83 | * that works correctly for most supported systems. |
| 84 | * The size can be set in bytes or as a percentage of the total memory |
| 85 | * in the system. |
| 86 | * |
| 87 | * Users, who want to set the size of global CMA area for their system |
| 88 | * should use cma= kernel parameter. |
| 89 | */ |
Vitaly Andrianov | 2ee0174 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 90 | static const phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M; |
| 91 | static phys_addr_t size_cmdline = -1; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 92 | |
| 93 | static int __init early_cma(char *p) |
| 94 | { |
| 95 | pr_debug("%s(%s)\n", __func__, p); |
| 96 | size_cmdline = memparse(p, &p); |
| 97 | return 0; |
| 98 | } |
| 99 | early_param("cma", early_cma); |
| 100 | |
| 101 | #ifdef CONFIG_CMA_SIZE_PERCENTAGE |
| 102 | |
Vitaly Andrianov | 2ee0174 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 103 | static phys_addr_t __init __maybe_unused cma_early_percent_memory(void) |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 104 | { |
| 105 | struct memblock_region *reg; |
| 106 | unsigned long total_pages = 0; |
| 107 | |
| 108 | /* |
| 109 | * We cannot use memblock_phys_mem_size() here, because |
| 110 | * memblock_analyze() has not been called yet. |
| 111 | */ |
| 112 | for_each_memblock(memory, reg) |
| 113 | total_pages += memblock_region_memory_end_pfn(reg) - |
| 114 | memblock_region_memory_base_pfn(reg); |
| 115 | |
| 116 | return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT; |
| 117 | } |
| 118 | |
| 119 | #else |
| 120 | |
Vitaly Andrianov | 2ee0174 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 121 | static inline __maybe_unused phys_addr_t cma_early_percent_memory(void) |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 122 | { |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | #endif |
| 127 | |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 128 | static __init int cma_activate_area(unsigned long base_pfn, unsigned long count) |
| 129 | { |
| 130 | unsigned long pfn = base_pfn; |
| 131 | unsigned i = count >> pageblock_order; |
| 132 | struct zone *zone; |
| 133 | |
| 134 | WARN_ON_ONCE(!pfn_valid(pfn)); |
| 135 | zone = page_zone(pfn_to_page(pfn)); |
| 136 | |
| 137 | do { |
| 138 | unsigned j; |
| 139 | base_pfn = pfn; |
| 140 | for (j = pageblock_nr_pages; j; --j, pfn++) { |
| 141 | WARN_ON_ONCE(!pfn_valid(pfn)); |
| 142 | if (page_zone(pfn_to_page(pfn)) != zone) |
| 143 | return -EINVAL; |
| 144 | } |
| 145 | init_cma_reserved_pageblock(pfn_to_page(base_pfn)); |
| 146 | } while (--i); |
| 147 | return 0; |
| 148 | } |
| 149 | |
| 150 | static __init struct cma *cma_create_area(unsigned long base_pfn, |
| 151 | unsigned long count) |
| 152 | { |
| 153 | int bitmap_size = BITS_TO_LONGS(count) * sizeof(long); |
| 154 | struct cma *cma; |
| 155 | int ret = -ENOMEM; |
| 156 | |
| 157 | pr_debug("%s(base %08lx, count %lx)\n", __func__, base_pfn, count); |
| 158 | |
| 159 | cma = kmalloc(sizeof *cma, GFP_KERNEL); |
| 160 | if (!cma) |
| 161 | return ERR_PTR(-ENOMEM); |
| 162 | |
| 163 | cma->base_pfn = base_pfn; |
| 164 | cma->count = count; |
| 165 | cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL); |
| 166 | |
| 167 | if (!cma->bitmap) |
| 168 | goto no_mem; |
| 169 | |
| 170 | ret = cma_activate_area(base_pfn, count); |
| 171 | if (ret) |
| 172 | goto error; |
| 173 | |
| 174 | pr_debug("%s: returned %p\n", __func__, (void *)cma); |
| 175 | return cma; |
| 176 | |
| 177 | error: |
| 178 | kfree(cma->bitmap); |
| 179 | no_mem: |
| 180 | kfree(cma); |
| 181 | return ERR_PTR(ret); |
| 182 | } |
| 183 | |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 184 | /** |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 185 | * dma_contiguous_reserve() - reserve area for contiguous memory handling |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 186 | * @limit: End address of the reserved memory (optional, 0 for any). |
| 187 | * |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 188 | * This function reserves memory from early allocator. It should be |
| 189 | * called by arch specific code once the early allocator (memblock or bootmem) |
| 190 | * has been activated and all other subsystems have already allocated/reserved |
| 191 | * memory. It reserves contiguous areas for global, device independent |
| 192 | * allocations and (optionally) all areas defined in device tree structures. |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 193 | */ |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 194 | void __init dma_contiguous_reserve(phys_addr_t limit) |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 195 | { |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 196 | phys_addr_t sel_size = 0; |
| 197 | |
| 198 | pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); |
| 199 | |
| 200 | if (size_cmdline != -1) { |
| 201 | sel_size = size_cmdline; |
| 202 | } else { |
| 203 | #ifdef CONFIG_CMA_SIZE_SEL_MBYTES |
| 204 | sel_size = size_bytes; |
| 205 | #elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE) |
| 206 | sel_size = cma_early_percent_memory(); |
| 207 | #elif defined(CONFIG_CMA_SIZE_SEL_MIN) |
| 208 | sel_size = min(size_bytes, cma_early_percent_memory()); |
| 209 | #elif defined(CONFIG_CMA_SIZE_SEL_MAX) |
| 210 | sel_size = max(size_bytes, cma_early_percent_memory()); |
| 211 | #endif |
| 212 | } |
| 213 | |
| 214 | if (sel_size) { |
| 215 | phys_addr_t base = 0; |
| 216 | pr_debug("%s: reserving %ld MiB for global area\n", __func__, |
| 217 | (unsigned long)sel_size / SZ_1M); |
| 218 | |
| 219 | if (dma_contiguous_reserve_area(sel_size, &base, limit) == 0) |
| 220 | dma_contiguous_def_base = base; |
| 221 | } |
| 222 | }; |
| 223 | |
| 224 | /** |
| 225 | * dma_contiguous_reserve_area() - reserve custom contiguous area |
| 226 | * @size: Size of the reserved area (in bytes), |
| 227 | * @base: Pointer to the base address of the reserved area, also used to return |
| 228 | * base address of the actually reserved area, optional, use pointer to |
| 229 | * 0 for any |
| 230 | * @limit: End address of the reserved memory (optional, 0 for any). |
| 231 | * |
| 232 | * This function reserves memory from early allocator. It should be |
| 233 | * called by arch specific code once the early allocator (memblock or bootmem) |
| 234 | * has been activated and all other subsystems have already allocated/reserved |
| 235 | * memory. This function allows to create custom reserved areas for specific |
| 236 | * devices. |
| 237 | */ |
| 238 | int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t *res_base, |
| 239 | phys_addr_t limit) |
| 240 | { |
| 241 | phys_addr_t base = *res_base; |
Vitaly Andrianov | 2ee0174 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 242 | phys_addr_t alignment; |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 243 | int ret = 0; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 244 | |
| 245 | pr_debug("%s(size %lx, base %08lx, limit %08lx)\n", __func__, |
| 246 | (unsigned long)size, (unsigned long)base, |
| 247 | (unsigned long)limit); |
| 248 | |
| 249 | /* Sanity checks */ |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 250 | if (cma_area_count == ARRAY_SIZE(cma_areas)) { |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 251 | pr_err("Not enough slots for CMA reserved regions!\n"); |
| 252 | return -ENOSPC; |
| 253 | } |
| 254 | |
| 255 | if (!size) |
| 256 | return -EINVAL; |
| 257 | |
| 258 | /* Sanitise input arguments */ |
Marek Szyprowski | 1273137 | 2012-08-27 20:27:19 +0200 | [diff] [blame] | 259 | alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order); |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 260 | base = ALIGN(base, alignment); |
| 261 | size = ALIGN(size, alignment); |
| 262 | limit &= ~(alignment - 1); |
| 263 | |
| 264 | /* Reserve memory */ |
| 265 | if (base) { |
| 266 | if (memblock_is_region_reserved(base, size) || |
| 267 | memblock_reserve(base, size) < 0) { |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 268 | ret = -EBUSY; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 269 | goto err; |
| 270 | } |
| 271 | } else { |
| 272 | /* |
| 273 | * Use __memblock_alloc_base() since |
| 274 | * memblock_alloc_base() panic()s. |
| 275 | */ |
| 276 | phys_addr_t addr = __memblock_alloc_base(size, alignment, limit); |
| 277 | if (!addr) { |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 278 | ret = -ENOMEM; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 279 | goto err; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 280 | } else { |
| 281 | base = addr; |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | /* |
| 286 | * Each reserved area must be initialised later, when more kernel |
| 287 | * subsystems (like slab allocator) are available. |
| 288 | */ |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 289 | cma_areas[cma_area_count].base = base; |
| 290 | cma_areas[cma_area_count].size = size; |
| 291 | cma_area_count++; |
| 292 | *res_base = base; |
| 293 | |
Vitaly Andrianov | 2ee0174 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 294 | pr_info("CMA: reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M, |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 295 | (unsigned long)base); |
| 296 | |
| 297 | /* Architecture specific contiguous memory fixup. */ |
| 298 | dma_contiguous_early_fixup(base, size); |
| 299 | return 0; |
| 300 | err: |
Vitaly Andrianov | 2ee0174 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 301 | pr_err("CMA: failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M); |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 302 | return ret; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 303 | } |
| 304 | |
| 305 | /** |
Marek Szyprowski | db7909c | 2013-02-14 13:45:27 +0100 | [diff] [blame^] | 306 | * dma_contiguous_add_device() - add device to custom contiguous reserved area |
| 307 | * @dev: Pointer to device structure. |
| 308 | * @base: Pointer to the base address of the reserved area returned by |
| 309 | * dma_contiguous_reserve_area() function, also used to return |
| 310 | * |
| 311 | * This function assigns the given device to the contiguous memory area |
| 312 | * reserved earlier by dma_contiguous_reserve_area() function. |
| 313 | */ |
| 314 | int __init dma_contiguous_add_device(struct device *dev, phys_addr_t base) |
| 315 | { |
| 316 | if (cma_map_count == ARRAY_SIZE(cma_maps)) { |
| 317 | pr_err("Not enough slots for CMA reserved regions!\n"); |
| 318 | return -ENOSPC; |
| 319 | } |
| 320 | cma_maps[cma_map_count].dev = dev; |
| 321 | cma_maps[cma_map_count].base = base; |
| 322 | cma_map_count++; |
| 323 | return 0; |
| 324 | } |
| 325 | |
| 326 | static int __init cma_init_reserved_areas(void) |
| 327 | { |
| 328 | struct cma *cma; |
| 329 | int i; |
| 330 | |
| 331 | for (i = 0; i < cma_area_count; i++) { |
| 332 | phys_addr_t base = PFN_DOWN(cma_areas[i].base); |
| 333 | unsigned int count = cma_areas[i].size >> PAGE_SHIFT; |
| 334 | |
| 335 | cma = cma_create_area(base, count); |
| 336 | if (!IS_ERR(cma)) |
| 337 | cma_areas[i].cma = cma; |
| 338 | } |
| 339 | |
| 340 | dma_contiguous_def_area = cma_get_area(dma_contiguous_def_base); |
| 341 | |
| 342 | for (i = 0; i < cma_map_count; i++) { |
| 343 | cma = cma_get_area(cma_maps[i].base); |
| 344 | dev_set_cma_area(cma_maps[i].dev, cma); |
| 345 | } |
| 346 | |
| 347 | return 0; |
| 348 | } |
| 349 | core_initcall(cma_init_reserved_areas); |
| 350 | |
| 351 | /** |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 352 | * dma_alloc_from_contiguous() - allocate pages from contiguous area |
| 353 | * @dev: Pointer to device for which the allocation is performed. |
| 354 | * @count: Requested number of pages. |
| 355 | * @align: Requested alignment of pages (in PAGE_SIZE order). |
| 356 | * |
| 357 | * This function allocates memory buffer for specified device. It uses |
| 358 | * device specific contiguous memory area if available or the default |
| 359 | * global one. Requires architecture specific get_dev_cma_area() helper |
| 360 | * function. |
| 361 | */ |
| 362 | struct page *dma_alloc_from_contiguous(struct device *dev, int count, |
| 363 | unsigned int align) |
| 364 | { |
| 365 | unsigned long mask, pfn, pageno, start = 0; |
| 366 | struct cma *cma = dev_get_cma_area(dev); |
Michal Nazarewicz | 81e1096 | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 367 | struct page *page = NULL; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 368 | int ret; |
Liam Mark | cc2d4bd | 2013-01-16 10:14:40 -0800 | [diff] [blame] | 369 | int tries = 0; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 370 | |
| 371 | if (!cma || !cma->count) |
| 372 | return NULL; |
| 373 | |
| 374 | if (align > CONFIG_CMA_ALIGNMENT) |
| 375 | align = CONFIG_CMA_ALIGNMENT; |
| 376 | |
| 377 | pr_debug("%s(cma %p, count %d, align %d)\n", __func__, (void *)cma, |
| 378 | count, align); |
| 379 | |
| 380 | if (!count) |
| 381 | return NULL; |
| 382 | |
| 383 | mask = (1 << align) - 1; |
| 384 | |
| 385 | mutex_lock(&cma_mutex); |
| 386 | |
| 387 | for (;;) { |
| 388 | pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count, |
| 389 | start, count, mask); |
Michal Nazarewicz | 81e1096 | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 390 | if (pageno >= cma->count) |
| 391 | break; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 392 | |
| 393 | pfn = cma->base_pfn + pageno; |
| 394 | ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA); |
| 395 | if (ret == 0) { |
| 396 | bitmap_set(cma->bitmap, pageno, count); |
Michal Nazarewicz | 81e1096 | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 397 | page = pfn_to_page(pfn); |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 398 | break; |
| 399 | } else if (ret != -EBUSY) { |
Michal Nazarewicz | 81e1096 | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 400 | break; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 401 | } |
Liam Mark | cc2d4bd | 2013-01-16 10:14:40 -0800 | [diff] [blame] | 402 | tries++; |
| 403 | trace_dma_alloc_contiguous_retry(tries); |
| 404 | |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 405 | pr_debug("%s(): memory range at %p is busy, retrying\n", |
| 406 | __func__, pfn_to_page(pfn)); |
| 407 | /* try again with a bit different memory target */ |
| 408 | start = pageno + mask + 1; |
| 409 | } |
| 410 | |
| 411 | mutex_unlock(&cma_mutex); |
Michal Nazarewicz | 81e1096 | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 412 | pr_debug("%s(): returned %p\n", __func__, page); |
| 413 | return page; |
Marek Szyprowski | 55bb033 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 414 | } |
| 415 | |
| 416 | /** |
| 417 | * dma_release_from_contiguous() - release allocated pages |
| 418 | * @dev: Pointer to device for which the pages were allocated. |
| 419 | * @pages: Allocated pages. |
| 420 | * @count: Number of allocated pages. |
| 421 | * |
| 422 | * This function releases memory allocated by dma_alloc_from_contiguous(). |
| 423 | * It returns false when provided pages do not belong to contiguous area and |
| 424 | * true otherwise. |
| 425 | */ |
| 426 | bool dma_release_from_contiguous(struct device *dev, struct page *pages, |
| 427 | int count) |
| 428 | { |
| 429 | struct cma *cma = dev_get_cma_area(dev); |
| 430 | unsigned long pfn; |
| 431 | |
| 432 | if (!cma || !pages) |
| 433 | return false; |
| 434 | |
| 435 | pr_debug("%s(page %p)\n", __func__, (void *)pages); |
| 436 | |
| 437 | pfn = page_to_pfn(pages); |
| 438 | |
| 439 | if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count) |
| 440 | return false; |
| 441 | |
| 442 | VM_BUG_ON(pfn + count > cma->base_pfn + cma->count); |
| 443 | |
| 444 | mutex_lock(&cma_mutex); |
| 445 | bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count); |
| 446 | free_contig_range(pfn, count); |
| 447 | mutex_unlock(&cma_mutex); |
| 448 | |
| 449 | return true; |
| 450 | } |