1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * arch-independent dma-mapping routines 4 * 5 * Copyright (c) 2006 SUSE Linux Products GmbH 6 * Copyright (c) 2006 Tejun Heo <teheo@suse.de> 7 */ 8 #include <linux/memblock.h> /* for max_pfn */ 9 #include <linux/acpi.h> 10 #include <linux/dma-direct.h> 11 #include <linux/dma-noncoherent.h> 12 #include <linux/export.h> 13 #include <linux/gfp.h> 14 #include <linux/of_device.h> 15 #include <linux/slab.h> 16 #include <linux/vmalloc.h> 17 18 /* 19 * Managed DMA API 20 */ 21 struct dma_devres { 22 size_t size; 23 void *vaddr; 24 dma_addr_t dma_handle; 25 unsigned long attrs; 26 }; 27 28 static void dmam_release(struct device *dev, void *res) 29 { 30 struct dma_devres *this = res; 31 32 dma_free_attrs(dev, this->size, this->vaddr, this->dma_handle, 33 this->attrs); 34 } 35 36 static int dmam_match(struct device *dev, void *res, void *match_data) 37 { 38 struct dma_devres *this = res, *match = match_data; 39 40 if (this->vaddr == match->vaddr) { 41 WARN_ON(this->size != match->size || 42 this->dma_handle != match->dma_handle); 43 return 1; 44 } 45 return 0; 46 } 47 48 /** 49 * dmam_free_coherent - Managed dma_free_coherent() 50 * @dev: Device to free coherent memory for 51 * @size: Size of allocation 52 * @vaddr: Virtual address of the memory to free 53 * @dma_handle: DMA handle of the memory to free 54 * 55 * Managed dma_free_coherent(). 56 */ 57 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr, 58 dma_addr_t dma_handle) 59 { 60 struct dma_devres match_data = { size, vaddr, dma_handle }; 61 62 dma_free_coherent(dev, size, vaddr, dma_handle); 63 WARN_ON(devres_destroy(dev, dmam_release, dmam_match, &match_data)); 64 } 65 EXPORT_SYMBOL(dmam_free_coherent); 66 67 /** 68 * dmam_alloc_attrs - Managed dma_alloc_attrs() 69 * @dev: Device to allocate non_coherent memory for 70 * @size: Size of allocation 71 * @dma_handle: Out argument for allocated DMA handle 72 * @gfp: Allocation flags 73 * @attrs: Flags in the DMA_ATTR_* namespace. 74 * 75 * Managed dma_alloc_attrs(). Memory allocated using this function will be 76 * automatically released on driver detach. 77 * 78 * RETURNS: 79 * Pointer to allocated memory on success, NULL on failure. 80 */ 81 void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, 82 gfp_t gfp, unsigned long attrs) 83 { 84 struct dma_devres *dr; 85 void *vaddr; 86 87 dr = devres_alloc(dmam_release, sizeof(*dr), gfp); 88 if (!dr) 89 return NULL; 90 91 vaddr = dma_alloc_attrs(dev, size, dma_handle, gfp, attrs); 92 if (!vaddr) { 93 devres_free(dr); 94 return NULL; 95 } 96 97 dr->vaddr = vaddr; 98 dr->dma_handle = *dma_handle; 99 dr->size = size; 100 dr->attrs = attrs; 101 102 devres_add(dev, dr); 103 104 return vaddr; 105 } 106 EXPORT_SYMBOL(dmam_alloc_attrs); 107 108 /* 109 * Create scatter-list for the already allocated DMA buffer. 110 */ 111 int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, 112 void *cpu_addr, dma_addr_t dma_addr, size_t size, 113 unsigned long attrs) 114 { 115 struct page *page = virt_to_page(cpu_addr); 116 int ret; 117 118 ret = sg_alloc_table(sgt, 1, GFP_KERNEL); 119 if (!ret) 120 sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); 121 return ret; 122 } 123 124 /* 125 * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems 126 * that the intention is to allow exporting memory allocated via the 127 * coherent DMA APIs through the dma_buf API, which only accepts a 128 * scattertable. This presents a couple of problems: 129 * 1. Not all memory allocated via the coherent DMA APIs is backed by 130 * a struct page 131 * 2. Passing coherent DMA memory into the streaming APIs is not allowed 132 * as we will try to flush the memory through a different alias to that 133 * actually being used (and the flushes are redundant.) 134 */ 135 int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, 136 void *cpu_addr, dma_addr_t dma_addr, size_t size, 137 unsigned long attrs) 138 { 139 const struct dma_map_ops *ops = get_dma_ops(dev); 140 141 if (dma_is_direct(ops)) 142 return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr, 143 size, attrs); 144 if (!ops->get_sgtable) 145 return -ENXIO; 146 return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs); 147 } 148 EXPORT_SYMBOL(dma_get_sgtable_attrs); 149 150 #ifdef CONFIG_MMU 151 /* 152 * Return the page attributes used for mapping dma_alloc_* memory, either in 153 * kernel space if remapping is needed, or to userspace through dma_mmap_*. 154 */ 155 pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs) 156 { 157 if (dev_is_dma_coherent(dev) || 158 (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) && 159 (attrs & DMA_ATTR_NON_CONSISTENT))) 160 return prot; 161 #ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE 162 if (attrs & DMA_ATTR_WRITE_COMBINE) 163 return pgprot_writecombine(prot); 164 #endif 165 return pgprot_dmacoherent(prot); 166 } 167 #endif /* CONFIG_MMU */ 168 169 /* 170 * Create userspace mapping for the DMA-coherent memory. 171 */ 172 int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, 173 void *cpu_addr, dma_addr_t dma_addr, size_t size, 174 unsigned long attrs) 175 { 176 #ifdef CONFIG_MMU 177 unsigned long user_count = vma_pages(vma); 178 unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; 179 unsigned long off = vma->vm_pgoff; 180 int ret = -ENXIO; 181 182 vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs); 183 184 if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) 185 return ret; 186 187 if (off >= count || user_count > count - off) 188 return -ENXIO; 189 190 return remap_pfn_range(vma, vma->vm_start, 191 page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, 192 user_count << PAGE_SHIFT, vma->vm_page_prot); 193 #else 194 return -ENXIO; 195 #endif /* CONFIG_MMU */ 196 } 197 198 /** 199 * dma_can_mmap - check if a given device supports dma_mmap_* 200 * @dev: device to check 201 * 202 * Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to 203 * map DMA allocations to userspace. 204 */ 205 bool dma_can_mmap(struct device *dev) 206 { 207 const struct dma_map_ops *ops = get_dma_ops(dev); 208 209 if (dma_is_direct(ops)) 210 return dma_direct_can_mmap(dev); 211 return ops->mmap != NULL; 212 } 213 EXPORT_SYMBOL_GPL(dma_can_mmap); 214 215 /** 216 * dma_mmap_attrs - map a coherent DMA allocation into user space 217 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 218 * @vma: vm_area_struct describing requested user mapping 219 * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs 220 * @dma_addr: device-view address returned from dma_alloc_attrs 221 * @size: size of memory originally requested in dma_alloc_attrs 222 * @attrs: attributes of mapping properties requested in dma_alloc_attrs 223 * 224 * Map a coherent DMA buffer previously allocated by dma_alloc_attrs into user 225 * space. The coherent DMA buffer must not be freed by the driver until the 226 * user space mapping has been released. 227 */ 228 int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, 229 void *cpu_addr, dma_addr_t dma_addr, size_t size, 230 unsigned long attrs) 231 { 232 const struct dma_map_ops *ops = get_dma_ops(dev); 233 234 if (dma_is_direct(ops)) 235 return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size, 236 attrs); 237 if (!ops->mmap) 238 return -ENXIO; 239 return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs); 240 } 241 EXPORT_SYMBOL(dma_mmap_attrs); 242 243 u64 dma_get_required_mask(struct device *dev) 244 { 245 const struct dma_map_ops *ops = get_dma_ops(dev); 246 247 if (dma_is_direct(ops)) 248 return dma_direct_get_required_mask(dev); 249 if (ops->get_required_mask) 250 return ops->get_required_mask(dev); 251 252 /* 253 * We require every DMA ops implementation to at least support a 32-bit 254 * DMA mask (and use bounce buffering if that isn't supported in 255 * hardware). As the direct mapping code has its own routine to 256 * actually report an optimal mask we default to 32-bit here as that 257 * is the right thing for most IOMMUs, and at least not actively 258 * harmful in general. 259 */ 260 return DMA_BIT_MASK(32); 261 } 262 EXPORT_SYMBOL_GPL(dma_get_required_mask); 263 264 void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, 265 gfp_t flag, unsigned long attrs) 266 { 267 const struct dma_map_ops *ops = get_dma_ops(dev); 268 void *cpu_addr; 269 270 WARN_ON_ONCE(!dev->coherent_dma_mask); 271 272 if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr)) 273 return cpu_addr; 274 275 /* let the implementation decide on the zone to allocate from: */ 276 flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM); 277 278 if (dma_is_direct(ops)) 279 cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs); 280 else if (ops->alloc) 281 cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs); 282 else 283 return NULL; 284 285 debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr); 286 return cpu_addr; 287 } 288 EXPORT_SYMBOL(dma_alloc_attrs); 289 290 void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, 291 dma_addr_t dma_handle, unsigned long attrs) 292 { 293 const struct dma_map_ops *ops = get_dma_ops(dev); 294 295 if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr)) 296 return; 297 /* 298 * On non-coherent platforms which implement DMA-coherent buffers via 299 * non-cacheable remaps, ops->free() may call vunmap(). Thus getting 300 * this far in IRQ context is a) at risk of a BUG_ON() or trying to 301 * sleep on some machines, and b) an indication that the driver is 302 * probably misusing the coherent API anyway. 303 */ 304 WARN_ON(irqs_disabled()); 305 306 if (!cpu_addr) 307 return; 308 309 debug_dma_free_coherent(dev, size, cpu_addr, dma_handle); 310 if (dma_is_direct(ops)) 311 dma_direct_free(dev, size, cpu_addr, dma_handle, attrs); 312 else if (ops->free) 313 ops->free(dev, size, cpu_addr, dma_handle, attrs); 314 } 315 EXPORT_SYMBOL(dma_free_attrs); 316 317 int dma_supported(struct device *dev, u64 mask) 318 { 319 const struct dma_map_ops *ops = get_dma_ops(dev); 320 321 if (dma_is_direct(ops)) 322 return dma_direct_supported(dev, mask); 323 if (!ops->dma_supported) 324 return 1; 325 return ops->dma_supported(dev, mask); 326 } 327 EXPORT_SYMBOL(dma_supported); 328 329 #ifdef CONFIG_ARCH_HAS_DMA_SET_MASK 330 void arch_dma_set_mask(struct device *dev, u64 mask); 331 #else 332 #define arch_dma_set_mask(dev, mask) do { } while (0) 333 #endif 334 335 int dma_set_mask(struct device *dev, u64 mask) 336 { 337 /* 338 * Truncate the mask to the actually supported dma_addr_t width to 339 * avoid generating unsupportable addresses. 340 */ 341 mask = (dma_addr_t)mask; 342 343 if (!dev->dma_mask || !dma_supported(dev, mask)) 344 return -EIO; 345 346 arch_dma_set_mask(dev, mask); 347 *dev->dma_mask = mask; 348 return 0; 349 } 350 EXPORT_SYMBOL(dma_set_mask); 351 352 #ifndef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK 353 int dma_set_coherent_mask(struct device *dev, u64 mask) 354 { 355 /* 356 * Truncate the mask to the actually supported dma_addr_t width to 357 * avoid generating unsupportable addresses. 358 */ 359 mask = (dma_addr_t)mask; 360 361 if (!dma_supported(dev, mask)) 362 return -EIO; 363 364 dev->coherent_dma_mask = mask; 365 return 0; 366 } 367 EXPORT_SYMBOL(dma_set_coherent_mask); 368 #endif 369 370 void dma_cache_sync(struct device *dev, void *vaddr, size_t size, 371 enum dma_data_direction dir) 372 { 373 const struct dma_map_ops *ops = get_dma_ops(dev); 374 375 BUG_ON(!valid_dma_direction(dir)); 376 377 if (dma_is_direct(ops)) 378 arch_dma_cache_sync(dev, vaddr, size, dir); 379 else if (ops->cache_sync) 380 ops->cache_sync(dev, vaddr, size, dir); 381 } 382 EXPORT_SYMBOL(dma_cache_sync); 383 384 size_t dma_max_mapping_size(struct device *dev) 385 { 386 const struct dma_map_ops *ops = get_dma_ops(dev); 387 size_t size = SIZE_MAX; 388 389 if (dma_is_direct(ops)) 390 size = dma_direct_max_mapping_size(dev); 391 else if (ops && ops->max_mapping_size) 392 size = ops->max_mapping_size(dev); 393 394 return size; 395 } 396 EXPORT_SYMBOL_GPL(dma_max_mapping_size); 397 398 unsigned long dma_get_merge_boundary(struct device *dev) 399 { 400 const struct dma_map_ops *ops = get_dma_ops(dev); 401 402 if (!ops || !ops->get_merge_boundary) 403 return 0; /* can't merge */ 404 405 return ops->get_merge_boundary(dev); 406 } 407 EXPORT_SYMBOL_GPL(dma_get_merge_boundary); 408