Marek Szyprowski | c64be2b | 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> |
Laurent Pinchart | 446c82f | 2012-10-18 09:29:44 +0200 | [diff] [blame] | 30 | #include <linux/sizes.h> |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 31 | #include <linux/slab.h> |
| 32 | #include <linux/swap.h> |
| 33 | #include <linux/mm_types.h> |
| 34 | #include <linux/dma-contiguous.h> |
Joonsoo Kim | a15bc0b | 2014-08-06 16:05:21 -0700 | [diff] [blame^] | 35 | #include <linux/log2.h> |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 36 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 37 | struct cma { |
| 38 | unsigned long base_pfn; |
| 39 | unsigned long count; |
| 40 | unsigned long *bitmap; |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 41 | struct mutex lock; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 42 | }; |
| 43 | |
| 44 | struct cma *dma_contiguous_default_area; |
| 45 | |
| 46 | #ifdef CONFIG_CMA_SIZE_MBYTES |
| 47 | #define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES |
| 48 | #else |
| 49 | #define CMA_SIZE_MBYTES 0 |
| 50 | #endif |
| 51 | |
| 52 | /* |
| 53 | * Default global CMA area size can be defined in kernel's .config. |
Michael Opdenacker | 7367880 | 2013-09-18 06:04:48 +0200 | [diff] [blame] | 54 | * This is useful mainly for distro maintainers to create a kernel |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 55 | * that works correctly for most supported systems. |
| 56 | * The size can be set in bytes or as a percentage of the total memory |
| 57 | * in the system. |
| 58 | * |
| 59 | * Users, who want to set the size of global CMA area for their system |
| 60 | * should use cma= kernel parameter. |
| 61 | */ |
Vitaly Andrianov | 4009793 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 62 | static const phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M; |
| 63 | static phys_addr_t size_cmdline = -1; |
Akinobu Mita | 5ea3b1b | 2014-06-04 16:06:54 -0700 | [diff] [blame] | 64 | static phys_addr_t base_cmdline; |
| 65 | static phys_addr_t limit_cmdline; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 66 | |
| 67 | static int __init early_cma(char *p) |
| 68 | { |
| 69 | pr_debug("%s(%s)\n", __func__, p); |
| 70 | size_cmdline = memparse(p, &p); |
Akinobu Mita | 5ea3b1b | 2014-06-04 16:06:54 -0700 | [diff] [blame] | 71 | if (*p != '@') |
| 72 | return 0; |
| 73 | base_cmdline = memparse(p + 1, &p); |
| 74 | if (*p != '-') { |
| 75 | limit_cmdline = base_cmdline + size_cmdline; |
| 76 | return 0; |
| 77 | } |
| 78 | limit_cmdline = memparse(p + 1, &p); |
| 79 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 80 | return 0; |
| 81 | } |
| 82 | early_param("cma", early_cma); |
| 83 | |
| 84 | #ifdef CONFIG_CMA_SIZE_PERCENTAGE |
| 85 | |
Vitaly Andrianov | 4009793 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 86 | static phys_addr_t __init __maybe_unused cma_early_percent_memory(void) |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 87 | { |
| 88 | struct memblock_region *reg; |
| 89 | unsigned long total_pages = 0; |
| 90 | |
| 91 | /* |
| 92 | * We cannot use memblock_phys_mem_size() here, because |
| 93 | * memblock_analyze() has not been called yet. |
| 94 | */ |
| 95 | for_each_memblock(memory, reg) |
| 96 | total_pages += memblock_region_memory_end_pfn(reg) - |
| 97 | memblock_region_memory_base_pfn(reg); |
| 98 | |
| 99 | return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT; |
| 100 | } |
| 101 | |
| 102 | #else |
| 103 | |
Vitaly Andrianov | 4009793 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 104 | static inline __maybe_unused phys_addr_t cma_early_percent_memory(void) |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 105 | { |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | #endif |
| 110 | |
| 111 | /** |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 112 | * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 113 | * @limit: End address of the reserved memory (optional, 0 for any). |
| 114 | * |
| 115 | * This function reserves memory from early allocator. It should be |
| 116 | * called by arch specific code once the early allocator (memblock or bootmem) |
| 117 | * has been activated and all other subsystems have already allocated/reserved |
| 118 | * memory. |
| 119 | */ |
| 120 | void __init dma_contiguous_reserve(phys_addr_t limit) |
| 121 | { |
Vitaly Andrianov | 4009793 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 122 | phys_addr_t selected_size = 0; |
Akinobu Mita | 5ea3b1b | 2014-06-04 16:06:54 -0700 | [diff] [blame] | 123 | phys_addr_t selected_base = 0; |
| 124 | phys_addr_t selected_limit = limit; |
| 125 | bool fixed = false; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 126 | |
| 127 | pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); |
| 128 | |
| 129 | if (size_cmdline != -1) { |
| 130 | selected_size = size_cmdline; |
Akinobu Mita | 5ea3b1b | 2014-06-04 16:06:54 -0700 | [diff] [blame] | 131 | selected_base = base_cmdline; |
| 132 | selected_limit = min_not_zero(limit_cmdline, limit); |
| 133 | if (base_cmdline + size_cmdline == limit_cmdline) |
| 134 | fixed = true; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 135 | } else { |
| 136 | #ifdef CONFIG_CMA_SIZE_SEL_MBYTES |
| 137 | selected_size = size_bytes; |
| 138 | #elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE) |
| 139 | selected_size = cma_early_percent_memory(); |
| 140 | #elif defined(CONFIG_CMA_SIZE_SEL_MIN) |
| 141 | selected_size = min(size_bytes, cma_early_percent_memory()); |
| 142 | #elif defined(CONFIG_CMA_SIZE_SEL_MAX) |
| 143 | selected_size = max(size_bytes, cma_early_percent_memory()); |
| 144 | #endif |
| 145 | } |
| 146 | |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 147 | if (selected_size && !dma_contiguous_default_area) { |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 148 | pr_debug("%s: reserving %ld MiB for global area\n", __func__, |
Vitaly Andrianov | 4009793 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 149 | (unsigned long)selected_size / SZ_1M); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 150 | |
Akinobu Mita | 5ea3b1b | 2014-06-04 16:06:54 -0700 | [diff] [blame] | 151 | dma_contiguous_reserve_area(selected_size, selected_base, |
| 152 | selected_limit, |
| 153 | &dma_contiguous_default_area, |
| 154 | fixed); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 155 | } |
Akinobu Mita | 5ea3b1b | 2014-06-04 16:06:54 -0700 | [diff] [blame] | 156 | } |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 157 | |
| 158 | static DEFINE_MUTEX(cma_mutex); |
| 159 | |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 160 | static int __init cma_activate_area(struct cma *cma) |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 161 | { |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 162 | int bitmap_size = BITS_TO_LONGS(cma->count) * sizeof(long); |
| 163 | unsigned long base_pfn = cma->base_pfn, pfn = base_pfn; |
| 164 | unsigned i = cma->count >> pageblock_order; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 165 | struct zone *zone; |
| 166 | |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 167 | cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL); |
| 168 | |
| 169 | if (!cma->bitmap) |
| 170 | return -ENOMEM; |
| 171 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 172 | WARN_ON_ONCE(!pfn_valid(pfn)); |
| 173 | zone = page_zone(pfn_to_page(pfn)); |
| 174 | |
| 175 | do { |
| 176 | unsigned j; |
| 177 | base_pfn = pfn; |
| 178 | for (j = pageblock_nr_pages; j; --j, pfn++) { |
| 179 | WARN_ON_ONCE(!pfn_valid(pfn)); |
Joonsoo Kim | fe8eea4 | 2014-06-23 13:22:07 -0700 | [diff] [blame] | 180 | /* |
| 181 | * alloc_contig_range requires the pfn range |
| 182 | * specified to be in the same zone. Make this |
| 183 | * simple by forcing the entire CMA resv range |
| 184 | * to be in the same zone. |
| 185 | */ |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 186 | if (page_zone(pfn_to_page(pfn)) != zone) |
Joonsoo Kim | fe8eea4 | 2014-06-23 13:22:07 -0700 | [diff] [blame] | 187 | goto err; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 188 | } |
| 189 | init_cma_reserved_pageblock(pfn_to_page(base_pfn)); |
| 190 | } while (--i); |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 191 | |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 192 | mutex_init(&cma->lock); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 193 | return 0; |
Joonsoo Kim | fe8eea4 | 2014-06-23 13:22:07 -0700 | [diff] [blame] | 194 | |
| 195 | err: |
| 196 | kfree(cma->bitmap); |
| 197 | return -EINVAL; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 198 | } |
| 199 | |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 200 | static struct cma cma_areas[MAX_CMA_AREAS]; |
| 201 | static unsigned cma_area_count; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 202 | |
| 203 | static int __init cma_init_reserved_areas(void) |
| 204 | { |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 205 | int i; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 206 | |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 207 | for (i = 0; i < cma_area_count; i++) { |
| 208 | int ret = cma_activate_area(&cma_areas[i]); |
| 209 | if (ret) |
| 210 | return ret; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 211 | } |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 212 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 213 | return 0; |
| 214 | } |
| 215 | core_initcall(cma_init_reserved_areas); |
| 216 | |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 217 | static int __init __dma_contiguous_reserve_area(phys_addr_t size, |
| 218 | phys_addr_t base, phys_addr_t limit, |
Joonsoo Kim | a15bc0b | 2014-08-06 16:05:21 -0700 | [diff] [blame^] | 219 | phys_addr_t alignment, |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 220 | struct cma **res_cma, bool fixed) |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 221 | { |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 222 | struct cma *cma = &cma_areas[cma_area_count]; |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 223 | int ret = 0; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 224 | |
Joonsoo Kim | a15bc0b | 2014-08-06 16:05:21 -0700 | [diff] [blame^] | 225 | pr_debug("%s(size %lx, base %08lx, limit %08lx alignment %08lx)\n", |
| 226 | __func__, (unsigned long)size, (unsigned long)base, |
| 227 | (unsigned long)limit, (unsigned long)alignment); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 228 | |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 229 | if (cma_area_count == ARRAY_SIZE(cma_areas)) { |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 230 | pr_err("Not enough slots for CMA reserved regions!\n"); |
| 231 | return -ENOSPC; |
| 232 | } |
| 233 | |
| 234 | if (!size) |
| 235 | return -EINVAL; |
| 236 | |
Joonsoo Kim | a15bc0b | 2014-08-06 16:05:21 -0700 | [diff] [blame^] | 237 | if (alignment && !is_power_of_2(alignment)) |
| 238 | return -EINVAL; |
| 239 | |
| 240 | /* |
| 241 | * Sanitise input arguments. |
| 242 | * Pages both ends in CMA area could be merged into adjacent unmovable |
| 243 | * migratetype page by page allocator's buddy algorithm. In the case, |
| 244 | * you couldn't get a contiguous memory, which is not what we want. |
| 245 | */ |
| 246 | alignment = max(alignment, |
| 247 | (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order)); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 248 | base = ALIGN(base, alignment); |
| 249 | size = ALIGN(size, alignment); |
| 250 | limit &= ~(alignment - 1); |
| 251 | |
| 252 | /* Reserve memory */ |
Akinobu Mita | 5ea3b1b | 2014-06-04 16:06:54 -0700 | [diff] [blame] | 253 | if (base && fixed) { |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 254 | if (memblock_is_region_reserved(base, size) || |
| 255 | memblock_reserve(base, size) < 0) { |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 256 | ret = -EBUSY; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 257 | goto err; |
| 258 | } |
| 259 | } else { |
Akinobu Mita | 5ea3b1b | 2014-06-04 16:06:54 -0700 | [diff] [blame] | 260 | phys_addr_t addr = memblock_alloc_range(size, alignment, base, |
| 261 | limit); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 262 | if (!addr) { |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 263 | ret = -ENOMEM; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 264 | goto err; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 265 | } else { |
| 266 | base = addr; |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | /* |
| 271 | * Each reserved area must be initialised later, when more kernel |
| 272 | * subsystems (like slab allocator) are available. |
| 273 | */ |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 274 | cma->base_pfn = PFN_DOWN(base); |
| 275 | cma->count = size >> PAGE_SHIFT; |
| 276 | *res_cma = cma; |
| 277 | cma_area_count++; |
| 278 | |
Vitaly Andrianov | 4009793 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 279 | pr_info("CMA: reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M, |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 280 | (unsigned long)base); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 281 | return 0; |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 282 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 283 | err: |
Vitaly Andrianov | 4009793 | 2012-12-05 09:29:25 -0500 | [diff] [blame] | 284 | pr_err("CMA: failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M); |
Marek Szyprowski | a254738 | 2013-07-29 14:31:45 +0200 | [diff] [blame] | 285 | return ret; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 286 | } |
| 287 | |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 288 | /** |
| 289 | * dma_contiguous_reserve_area() - reserve custom contiguous area |
| 290 | * @size: Size of the reserved area (in bytes), |
| 291 | * @base: Base address of the reserved area optional, use 0 for any |
| 292 | * @limit: End address of the reserved memory (optional, 0 for any). |
| 293 | * @res_cma: Pointer to store the created cma region. |
| 294 | * @fixed: hint about where to place the reserved area |
| 295 | * |
| 296 | * This function reserves memory from early allocator. It should be |
| 297 | * called by arch specific code once the early allocator (memblock or bootmem) |
| 298 | * has been activated and all other subsystems have already allocated/reserved |
| 299 | * memory. This function allows to create custom reserved areas for specific |
| 300 | * devices. |
| 301 | * |
| 302 | * If @fixed is true, reserve contiguous area at exactly @base. If false, |
| 303 | * reserve in range from @base to @limit. |
| 304 | */ |
| 305 | int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, |
| 306 | phys_addr_t limit, struct cma **res_cma, |
| 307 | bool fixed) |
| 308 | { |
| 309 | int ret; |
| 310 | |
Joonsoo Kim | a15bc0b | 2014-08-06 16:05:21 -0700 | [diff] [blame^] | 311 | ret = __dma_contiguous_reserve_area(size, base, limit, 0, |
| 312 | res_cma, fixed); |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 313 | if (ret) |
| 314 | return ret; |
| 315 | |
| 316 | /* Architecture specific contiguous memory fixup. */ |
| 317 | dma_contiguous_early_fixup(PFN_PHYS((*res_cma)->base_pfn), |
| 318 | (*res_cma)->count << PAGE_SHIFT); |
| 319 | |
| 320 | return 0; |
| 321 | } |
| 322 | |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 323 | static void clear_cma_bitmap(struct cma *cma, unsigned long pfn, int count) |
| 324 | { |
| 325 | mutex_lock(&cma->lock); |
| 326 | bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count); |
| 327 | mutex_unlock(&cma->lock); |
| 328 | } |
| 329 | |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 330 | static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count, |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 331 | unsigned int align) |
| 332 | { |
| 333 | unsigned long mask, pfn, pageno, start = 0; |
Michal Nazarewicz | bdd43cb | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 334 | struct page *page = NULL; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 335 | int ret; |
| 336 | |
| 337 | if (!cma || !cma->count) |
| 338 | return NULL; |
| 339 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 340 | pr_debug("%s(cma %p, count %d, align %d)\n", __func__, (void *)cma, |
| 341 | count, align); |
| 342 | |
| 343 | if (!count) |
| 344 | return NULL; |
| 345 | |
| 346 | mask = (1 << align) - 1; |
| 347 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 348 | |
| 349 | for (;;) { |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 350 | mutex_lock(&cma->lock); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 351 | pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count, |
| 352 | start, count, mask); |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 353 | if (pageno >= cma->count) { |
Joonsoo Kim | f70e3c4 | 2014-05-29 15:29:18 +0900 | [diff] [blame] | 354 | mutex_unlock(&cma->lock); |
Michal Nazarewicz | bdd43cb | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 355 | break; |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 356 | } |
| 357 | bitmap_set(cma->bitmap, pageno, count); |
| 358 | /* |
| 359 | * It's safe to drop the lock here. We've marked this region for |
| 360 | * our exclusive use. If the migration fails we will take the |
| 361 | * lock again and unmark it. |
| 362 | */ |
| 363 | mutex_unlock(&cma->lock); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 364 | |
| 365 | pfn = cma->base_pfn + pageno; |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 366 | mutex_lock(&cma_mutex); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 367 | ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA); |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 368 | mutex_unlock(&cma_mutex); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 369 | if (ret == 0) { |
Michal Nazarewicz | bdd43cb | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 370 | page = pfn_to_page(pfn); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 371 | break; |
| 372 | } else if (ret != -EBUSY) { |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 373 | clear_cma_bitmap(cma, pfn, count); |
Michal Nazarewicz | bdd43cb | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 374 | break; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 375 | } |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 376 | clear_cma_bitmap(cma, pfn, count); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 377 | pr_debug("%s(): memory range at %p is busy, retrying\n", |
| 378 | __func__, pfn_to_page(pfn)); |
| 379 | /* try again with a bit different memory target */ |
| 380 | start = pageno + mask + 1; |
| 381 | } |
| 382 | |
Michal Nazarewicz | bdd43cb | 2012-09-05 07:50:41 +0200 | [diff] [blame] | 383 | pr_debug("%s(): returned %p\n", __func__, page); |
| 384 | return page; |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 385 | } |
| 386 | |
| 387 | /** |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 388 | * dma_alloc_from_contiguous() - allocate pages from contiguous area |
| 389 | * @dev: Pointer to device for which the allocation is performed. |
| 390 | * @count: Requested number of pages. |
| 391 | * @align: Requested alignment of pages (in PAGE_SIZE order). |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 392 | * |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 393 | * This function allocates memory buffer for specified device. It uses |
| 394 | * device specific contiguous memory area if available or the default |
| 395 | * global one. Requires architecture specific dev_get_cma_area() helper |
| 396 | * function. |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 397 | */ |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 398 | struct page *dma_alloc_from_contiguous(struct device *dev, int count, |
| 399 | unsigned int align) |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 400 | { |
| 401 | struct cma *cma = dev_get_cma_area(dev); |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 402 | |
| 403 | if (align > CONFIG_CMA_ALIGNMENT) |
| 404 | align = CONFIG_CMA_ALIGNMENT; |
| 405 | |
| 406 | return __dma_alloc_from_contiguous(cma, count, align); |
| 407 | } |
| 408 | |
| 409 | static bool __dma_release_from_contiguous(struct cma *cma, struct page *pages, |
| 410 | int count) |
| 411 | { |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 412 | unsigned long pfn; |
| 413 | |
| 414 | if (!cma || !pages) |
| 415 | return false; |
| 416 | |
| 417 | pr_debug("%s(page %p)\n", __func__, (void *)pages); |
| 418 | |
| 419 | pfn = page_to_pfn(pages); |
| 420 | |
| 421 | if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count) |
| 422 | return false; |
| 423 | |
| 424 | VM_BUG_ON(pfn + count > cma->base_pfn + cma->count); |
| 425 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 426 | free_contig_range(pfn, count); |
Laura Abbott | 7ee793a | 2014-02-25 11:01:19 -0800 | [diff] [blame] | 427 | clear_cma_bitmap(cma, pfn, count); |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 428 | |
| 429 | return true; |
| 430 | } |
Joonsoo Kim | 3162bbd | 2014-08-06 16:05:19 -0700 | [diff] [blame] | 431 | |
| 432 | /** |
| 433 | * dma_release_from_contiguous() - release allocated pages |
| 434 | * @dev: Pointer to device for which the pages were allocated. |
| 435 | * @pages: Allocated pages. |
| 436 | * @count: Number of allocated pages. |
| 437 | * |
| 438 | * This function releases memory allocated by dma_alloc_from_contiguous(). |
| 439 | * It returns false when provided pages do not belong to contiguous area and |
| 440 | * true otherwise. |
| 441 | */ |
| 442 | bool dma_release_from_contiguous(struct device *dev, struct page *pages, |
| 443 | int count) |
| 444 | { |
| 445 | struct cma *cma = dev_get_cma_area(dev); |
| 446 | |
| 447 | return __dma_release_from_contiguous(cma, pages, count); |
| 448 | } |