1 // SPDX-License-Identifier: GPL-2.0
3 * arch-independent dma-mapping routines
5 * Copyright (c) 2006 SUSE Linux Products GmbH
6 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
8 #include <linux/memblock.h> /* for max_pfn */
9 #include <linux/acpi.h>
10 #include <linux/dma-map-ops.h>
11 #include <linux/export.h>
12 #include <linux/gfp.h>
13 #include <linux/of_device.h>
14 #include <linux/slab.h>
15 #include <linux/vmalloc.h>
19 bool dma_default_coherent;
27 dma_addr_t dma_handle;
31 static void dmam_release(struct device *dev, void *res)
33 struct dma_devres *this = res;
35 dma_free_attrs(dev, this->size, this->vaddr, this->dma_handle,
39 static int dmam_match(struct device *dev, void *res, void *match_data)
41 struct dma_devres *this = res, *match = match_data;
43 if (this->vaddr == match->vaddr) {
44 WARN_ON(this->size != match->size ||
45 this->dma_handle != match->dma_handle);
52 * dmam_free_coherent - Managed dma_free_coherent()
53 * @dev: Device to free coherent memory for
54 * @size: Size of allocation
55 * @vaddr: Virtual address of the memory to free
56 * @dma_handle: DMA handle of the memory to free
58 * Managed dma_free_coherent().
60 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
61 dma_addr_t dma_handle)
63 struct dma_devres match_data = { size, vaddr, dma_handle };
65 dma_free_coherent(dev, size, vaddr, dma_handle);
66 WARN_ON(devres_destroy(dev, dmam_release, dmam_match, &match_data));
68 EXPORT_SYMBOL(dmam_free_coherent);
71 * dmam_alloc_attrs - Managed dma_alloc_attrs()
72 * @dev: Device to allocate non_coherent memory for
73 * @size: Size of allocation
74 * @dma_handle: Out argument for allocated DMA handle
75 * @gfp: Allocation flags
76 * @attrs: Flags in the DMA_ATTR_* namespace.
78 * Managed dma_alloc_attrs(). Memory allocated using this function will be
79 * automatically released on driver detach.
82 * Pointer to allocated memory on success, NULL on failure.
84 void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
85 gfp_t gfp, unsigned long attrs)
87 struct dma_devres *dr;
90 dr = devres_alloc(dmam_release, sizeof(*dr), gfp);
94 vaddr = dma_alloc_attrs(dev, size, dma_handle, gfp, attrs);
101 dr->dma_handle = *dma_handle;
109 EXPORT_SYMBOL(dmam_alloc_attrs);
111 static bool dma_go_direct(struct device *dev, dma_addr_t mask,
112 const struct dma_map_ops *ops)
116 #ifdef CONFIG_DMA_OPS_BYPASS
117 if (dev->dma_ops_bypass)
118 return min_not_zero(mask, dev->bus_dma_limit) >=
119 dma_direct_get_required_mask(dev);
126 * Check if the devices uses a direct mapping for streaming DMA operations.
127 * This allows IOMMU drivers to set a bypass mode if the DMA mask is large
130 static inline bool dma_alloc_direct(struct device *dev,
131 const struct dma_map_ops *ops)
133 return dma_go_direct(dev, dev->coherent_dma_mask, ops);
136 static inline bool dma_map_direct(struct device *dev,
137 const struct dma_map_ops *ops)
139 return dma_go_direct(dev, *dev->dma_mask, ops);
142 dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
143 size_t offset, size_t size, enum dma_data_direction dir,
146 const struct dma_map_ops *ops = get_dma_ops(dev);
149 BUG_ON(!valid_dma_direction(dir));
151 if (WARN_ON_ONCE(!dev->dma_mask))
152 return DMA_MAPPING_ERROR;
154 if (dma_map_direct(dev, ops) ||
155 arch_dma_map_page_direct(dev, page_to_phys(page) + offset + size))
156 addr = dma_direct_map_page(dev, page, offset, size, dir, attrs);
158 addr = ops->map_page(dev, page, offset, size, dir, attrs);
159 debug_dma_map_page(dev, page, offset, size, dir, addr);
163 EXPORT_SYMBOL(dma_map_page_attrs);
165 void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
166 enum dma_data_direction dir, unsigned long attrs)
168 const struct dma_map_ops *ops = get_dma_ops(dev);
170 BUG_ON(!valid_dma_direction(dir));
171 if (dma_map_direct(dev, ops) ||
172 arch_dma_unmap_page_direct(dev, addr + size))
173 dma_direct_unmap_page(dev, addr, size, dir, attrs);
174 else if (ops->unmap_page)
175 ops->unmap_page(dev, addr, size, dir, attrs);
176 debug_dma_unmap_page(dev, addr, size, dir);
178 EXPORT_SYMBOL(dma_unmap_page_attrs);
181 * dma_maps_sg_attrs returns 0 on error and > 0 on success.
182 * It should never return a value < 0.
184 int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents,
185 enum dma_data_direction dir, unsigned long attrs)
187 const struct dma_map_ops *ops = get_dma_ops(dev);
190 BUG_ON(!valid_dma_direction(dir));
192 if (WARN_ON_ONCE(!dev->dma_mask))
195 if (dma_map_direct(dev, ops) ||
196 arch_dma_map_sg_direct(dev, sg, nents))
197 ents = dma_direct_map_sg(dev, sg, nents, dir, attrs);
199 ents = ops->map_sg(dev, sg, nents, dir, attrs);
201 debug_dma_map_sg(dev, sg, nents, ents, dir);
205 EXPORT_SYMBOL(dma_map_sg_attrs);
207 void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
208 int nents, enum dma_data_direction dir,
211 const struct dma_map_ops *ops = get_dma_ops(dev);
213 BUG_ON(!valid_dma_direction(dir));
214 debug_dma_unmap_sg(dev, sg, nents, dir);
215 if (dma_map_direct(dev, ops) ||
216 arch_dma_unmap_sg_direct(dev, sg, nents))
217 dma_direct_unmap_sg(dev, sg, nents, dir, attrs);
218 else if (ops->unmap_sg)
219 ops->unmap_sg(dev, sg, nents, dir, attrs);
221 EXPORT_SYMBOL(dma_unmap_sg_attrs);
223 dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
224 size_t size, enum dma_data_direction dir, unsigned long attrs)
226 const struct dma_map_ops *ops = get_dma_ops(dev);
227 dma_addr_t addr = DMA_MAPPING_ERROR;
229 BUG_ON(!valid_dma_direction(dir));
231 if (WARN_ON_ONCE(!dev->dma_mask))
232 return DMA_MAPPING_ERROR;
234 /* Don't allow RAM to be mapped */
235 if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr))))
236 return DMA_MAPPING_ERROR;
238 if (dma_map_direct(dev, ops))
239 addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs);
240 else if (ops->map_resource)
241 addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
243 debug_dma_map_resource(dev, phys_addr, size, dir, addr);
246 EXPORT_SYMBOL(dma_map_resource);
248 void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
249 enum dma_data_direction dir, unsigned long attrs)
251 const struct dma_map_ops *ops = get_dma_ops(dev);
253 BUG_ON(!valid_dma_direction(dir));
254 if (!dma_map_direct(dev, ops) && ops->unmap_resource)
255 ops->unmap_resource(dev, addr, size, dir, attrs);
256 debug_dma_unmap_resource(dev, addr, size, dir);
258 EXPORT_SYMBOL(dma_unmap_resource);
260 void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
261 enum dma_data_direction dir)
263 const struct dma_map_ops *ops = get_dma_ops(dev);
265 BUG_ON(!valid_dma_direction(dir));
266 if (dma_map_direct(dev, ops))
267 dma_direct_sync_single_for_cpu(dev, addr, size, dir);
268 else if (ops->sync_single_for_cpu)
269 ops->sync_single_for_cpu(dev, addr, size, dir);
270 debug_dma_sync_single_for_cpu(dev, addr, size, dir);
272 EXPORT_SYMBOL(dma_sync_single_for_cpu);
274 void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
275 size_t size, enum dma_data_direction dir)
277 const struct dma_map_ops *ops = get_dma_ops(dev);
279 BUG_ON(!valid_dma_direction(dir));
280 if (dma_map_direct(dev, ops))
281 dma_direct_sync_single_for_device(dev, addr, size, dir);
282 else if (ops->sync_single_for_device)
283 ops->sync_single_for_device(dev, addr, size, dir);
284 debug_dma_sync_single_for_device(dev, addr, size, dir);
286 EXPORT_SYMBOL(dma_sync_single_for_device);
288 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
289 int nelems, enum dma_data_direction dir)
291 const struct dma_map_ops *ops = get_dma_ops(dev);
293 BUG_ON(!valid_dma_direction(dir));
294 if (dma_map_direct(dev, ops))
295 dma_direct_sync_sg_for_cpu(dev, sg, nelems, dir);
296 else if (ops->sync_sg_for_cpu)
297 ops->sync_sg_for_cpu(dev, sg, nelems, dir);
298 debug_dma_sync_sg_for_cpu(dev, sg, nelems, dir);
300 EXPORT_SYMBOL(dma_sync_sg_for_cpu);
302 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
303 int nelems, enum dma_data_direction dir)
305 const struct dma_map_ops *ops = get_dma_ops(dev);
307 BUG_ON(!valid_dma_direction(dir));
308 if (dma_map_direct(dev, ops))
309 dma_direct_sync_sg_for_device(dev, sg, nelems, dir);
310 else if (ops->sync_sg_for_device)
311 ops->sync_sg_for_device(dev, sg, nelems, dir);
312 debug_dma_sync_sg_for_device(dev, sg, nelems, dir);
314 EXPORT_SYMBOL(dma_sync_sg_for_device);
317 * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
318 * that the intention is to allow exporting memory allocated via the
319 * coherent DMA APIs through the dma_buf API, which only accepts a
320 * scattertable. This presents a couple of problems:
321 * 1. Not all memory allocated via the coherent DMA APIs is backed by
323 * 2. Passing coherent DMA memory into the streaming APIs is not allowed
324 * as we will try to flush the memory through a different alias to that
325 * actually being used (and the flushes are redundant.)
327 int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
328 void *cpu_addr, dma_addr_t dma_addr, size_t size,
331 const struct dma_map_ops *ops = get_dma_ops(dev);
333 if (dma_alloc_direct(dev, ops))
334 return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr,
336 if (!ops->get_sgtable)
338 return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs);
340 EXPORT_SYMBOL(dma_get_sgtable_attrs);
344 * Return the page attributes used for mapping dma_alloc_* memory, either in
345 * kernel space if remapping is needed, or to userspace through dma_mmap_*.
347 pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
349 if (force_dma_unencrypted(dev))
350 prot = pgprot_decrypted(prot);
351 if (dev_is_dma_coherent(dev))
353 #ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
354 if (attrs & DMA_ATTR_WRITE_COMBINE)
355 return pgprot_writecombine(prot);
357 return pgprot_dmacoherent(prot);
359 #endif /* CONFIG_MMU */
362 * dma_can_mmap - check if a given device supports dma_mmap_*
363 * @dev: device to check
365 * Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to
366 * map DMA allocations to userspace.
368 bool dma_can_mmap(struct device *dev)
370 const struct dma_map_ops *ops = get_dma_ops(dev);
372 if (dma_alloc_direct(dev, ops))
373 return dma_direct_can_mmap(dev);
374 return ops->mmap != NULL;
376 EXPORT_SYMBOL_GPL(dma_can_mmap);
379 * dma_mmap_attrs - map a coherent DMA allocation into user space
380 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
381 * @vma: vm_area_struct describing requested user mapping
382 * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
383 * @dma_addr: device-view address returned from dma_alloc_attrs
384 * @size: size of memory originally requested in dma_alloc_attrs
385 * @attrs: attributes of mapping properties requested in dma_alloc_attrs
387 * Map a coherent DMA buffer previously allocated by dma_alloc_attrs into user
388 * space. The coherent DMA buffer must not be freed by the driver until the
389 * user space mapping has been released.
391 int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
392 void *cpu_addr, dma_addr_t dma_addr, size_t size,
395 const struct dma_map_ops *ops = get_dma_ops(dev);
397 if (dma_alloc_direct(dev, ops))
398 return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size,
402 return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
404 EXPORT_SYMBOL(dma_mmap_attrs);
406 u64 dma_get_required_mask(struct device *dev)
408 const struct dma_map_ops *ops = get_dma_ops(dev);
410 if (dma_alloc_direct(dev, ops))
411 return dma_direct_get_required_mask(dev);
412 if (ops->get_required_mask)
413 return ops->get_required_mask(dev);
416 * We require every DMA ops implementation to at least support a 32-bit
417 * DMA mask (and use bounce buffering if that isn't supported in
418 * hardware). As the direct mapping code has its own routine to
419 * actually report an optimal mask we default to 32-bit here as that
420 * is the right thing for most IOMMUs, and at least not actively
421 * harmful in general.
423 return DMA_BIT_MASK(32);
425 EXPORT_SYMBOL_GPL(dma_get_required_mask);
427 void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
428 gfp_t flag, unsigned long attrs)
430 const struct dma_map_ops *ops = get_dma_ops(dev);
433 WARN_ON_ONCE(!dev->coherent_dma_mask);
435 if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
438 /* let the implementation decide on the zone to allocate from: */
439 flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
441 if (dma_alloc_direct(dev, ops))
442 cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs);
444 cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
448 debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);
451 EXPORT_SYMBOL(dma_alloc_attrs);
453 void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
454 dma_addr_t dma_handle, unsigned long attrs)
456 const struct dma_map_ops *ops = get_dma_ops(dev);
458 if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr))
461 * On non-coherent platforms which implement DMA-coherent buffers via
462 * non-cacheable remaps, ops->free() may call vunmap(). Thus getting
463 * this far in IRQ context is a) at risk of a BUG_ON() or trying to
464 * sleep on some machines, and b) an indication that the driver is
465 * probably misusing the coherent API anyway.
467 WARN_ON(irqs_disabled());
472 debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
473 if (dma_alloc_direct(dev, ops))
474 dma_direct_free(dev, size, cpu_addr, dma_handle, attrs);
476 ops->free(dev, size, cpu_addr, dma_handle, attrs);
478 EXPORT_SYMBOL(dma_free_attrs);
480 struct page *dma_alloc_pages(struct device *dev, size_t size,
481 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
483 const struct dma_map_ops *ops = get_dma_ops(dev);
486 if (WARN_ON_ONCE(!dev->coherent_dma_mask))
488 if (WARN_ON_ONCE(gfp & (__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM)))
491 size = PAGE_ALIGN(size);
492 if (dma_alloc_direct(dev, ops))
493 page = dma_direct_alloc_pages(dev, size, dma_handle, dir, gfp);
494 else if (ops->alloc_pages)
495 page = ops->alloc_pages(dev, size, dma_handle, dir, gfp);
499 debug_dma_map_page(dev, page, 0, size, dir, *dma_handle);
503 EXPORT_SYMBOL_GPL(dma_alloc_pages);
505 void dma_free_pages(struct device *dev, size_t size, struct page *page,
506 dma_addr_t dma_handle, enum dma_data_direction dir)
508 const struct dma_map_ops *ops = get_dma_ops(dev);
510 size = PAGE_ALIGN(size);
511 debug_dma_unmap_page(dev, dma_handle, size, dir);
513 if (dma_alloc_direct(dev, ops))
514 dma_direct_free_pages(dev, size, page, dma_handle, dir);
515 else if (ops->free_pages)
516 ops->free_pages(dev, size, page, dma_handle, dir);
518 EXPORT_SYMBOL_GPL(dma_free_pages);
520 int dma_supported(struct device *dev, u64 mask)
522 const struct dma_map_ops *ops = get_dma_ops(dev);
525 * ->dma_supported sets the bypass flag, so we must always call
526 * into the method here unless the device is truly direct mapped.
529 return dma_direct_supported(dev, mask);
530 if (!ops->dma_supported)
532 return ops->dma_supported(dev, mask);
534 EXPORT_SYMBOL(dma_supported);
536 #ifdef CONFIG_ARCH_HAS_DMA_SET_MASK
537 void arch_dma_set_mask(struct device *dev, u64 mask);
539 #define arch_dma_set_mask(dev, mask) do { } while (0)
542 int dma_set_mask(struct device *dev, u64 mask)
545 * Truncate the mask to the actually supported dma_addr_t width to
546 * avoid generating unsupportable addresses.
548 mask = (dma_addr_t)mask;
550 if (!dev->dma_mask || !dma_supported(dev, mask))
553 arch_dma_set_mask(dev, mask);
554 *dev->dma_mask = mask;
557 EXPORT_SYMBOL(dma_set_mask);
559 #ifndef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK
560 int dma_set_coherent_mask(struct device *dev, u64 mask)
563 * Truncate the mask to the actually supported dma_addr_t width to
564 * avoid generating unsupportable addresses.
566 mask = (dma_addr_t)mask;
568 if (!dma_supported(dev, mask))
571 dev->coherent_dma_mask = mask;
574 EXPORT_SYMBOL(dma_set_coherent_mask);
577 size_t dma_max_mapping_size(struct device *dev)
579 const struct dma_map_ops *ops = get_dma_ops(dev);
580 size_t size = SIZE_MAX;
582 if (dma_map_direct(dev, ops))
583 size = dma_direct_max_mapping_size(dev);
584 else if (ops && ops->max_mapping_size)
585 size = ops->max_mapping_size(dev);
589 EXPORT_SYMBOL_GPL(dma_max_mapping_size);
591 bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
593 const struct dma_map_ops *ops = get_dma_ops(dev);
595 if (dma_map_direct(dev, ops))
596 return dma_direct_need_sync(dev, dma_addr);
597 return ops->sync_single_for_cpu || ops->sync_single_for_device;
599 EXPORT_SYMBOL_GPL(dma_need_sync);
601 unsigned long dma_get_merge_boundary(struct device *dev)
603 const struct dma_map_ops *ops = get_dma_ops(dev);
605 if (!ops || !ops->get_merge_boundary)
606 return 0; /* can't merge */
608 return ops->get_merge_boundary(dev);
610 EXPORT_SYMBOL_GPL(dma_get_merge_boundary);