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-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>
24 dma_addr_t dma_handle;
28 static void dmam_release(struct device *dev, void *res)
30 struct dma_devres *this = res;
32 dma_free_attrs(dev, this->size, this->vaddr, this->dma_handle,
36 static int dmam_match(struct device *dev, void *res, void *match_data)
38 struct dma_devres *this = res, *match = match_data;
40 if (this->vaddr == match->vaddr) {
41 WARN_ON(this->size != match->size ||
42 this->dma_handle != match->dma_handle);
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
55 * Managed dma_free_coherent().
57 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
58 dma_addr_t dma_handle)
60 struct dma_devres match_data = { size, vaddr, dma_handle };
62 dma_free_coherent(dev, size, vaddr, dma_handle);
63 WARN_ON(devres_destroy(dev, dmam_release, dmam_match, &match_data));
65 EXPORT_SYMBOL(dmam_free_coherent);
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.
75 * Managed dma_alloc_attrs(). Memory allocated using this function will be
76 * automatically released on driver detach.
79 * Pointer to allocated memory on success, NULL on failure.
81 void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
82 gfp_t gfp, unsigned long attrs)
84 struct dma_devres *dr;
87 dr = devres_alloc(dmam_release, sizeof(*dr), gfp);
91 vaddr = dma_alloc_attrs(dev, size, dma_handle, gfp, attrs);
98 dr->dma_handle = *dma_handle;
106 EXPORT_SYMBOL(dmam_alloc_attrs);
109 * Create scatter-list for the already allocated DMA buffer.
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,
115 struct page *page = virt_to_page(cpu_addr);
118 ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
120 sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
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
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.)
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,
139 const struct dma_map_ops *ops = get_dma_ops(dev);
141 if (dma_is_direct(ops))
142 return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr,
144 if (!ops->get_sgtable)
146 return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs);
148 EXPORT_SYMBOL(dma_get_sgtable_attrs);
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_*.
155 pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
157 if (dev_is_dma_coherent(dev) ||
158 (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) &&
159 (attrs & DMA_ATTR_NON_CONSISTENT)))
161 #ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
162 if (attrs & DMA_ATTR_WRITE_COMBINE)
163 return pgprot_writecombine(prot);
165 return pgprot_dmacoherent(prot);
167 #endif /* CONFIG_MMU */
170 * Create userspace mapping for the DMA-coherent memory.
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,
177 unsigned long user_count = vma_pages(vma);
178 unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
179 unsigned long off = vma->vm_pgoff;
182 vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
184 if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
187 if (off >= count || user_count > count - off)
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);
195 #endif /* CONFIG_MMU */
199 * dma_can_mmap - check if a given device supports dma_mmap_*
200 * @dev: device to check
202 * Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to
203 * map DMA allocations to userspace.
205 bool dma_can_mmap(struct device *dev)
207 const struct dma_map_ops *ops = get_dma_ops(dev);
209 if (dma_is_direct(ops))
210 return dma_direct_can_mmap(dev);
211 return ops->mmap != NULL;
213 EXPORT_SYMBOL_GPL(dma_can_mmap);
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
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.
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,
232 const struct dma_map_ops *ops = get_dma_ops(dev);
234 if (dma_is_direct(ops))
235 return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size,
239 return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
241 EXPORT_SYMBOL(dma_mmap_attrs);
243 u64 dma_get_required_mask(struct device *dev)
245 const struct dma_map_ops *ops = get_dma_ops(dev);
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);
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.
260 return DMA_BIT_MASK(32);
262 EXPORT_SYMBOL_GPL(dma_get_required_mask);
264 void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
265 gfp_t flag, unsigned long attrs)
267 const struct dma_map_ops *ops = get_dma_ops(dev);
270 WARN_ON_ONCE(!dev->coherent_dma_mask);
272 if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
275 /* let the implementation decide on the zone to allocate from: */
276 flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
278 if (dma_is_direct(ops))
279 cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs);
281 cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
285 debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);
288 EXPORT_SYMBOL(dma_alloc_attrs);
290 void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
291 dma_addr_t dma_handle, unsigned long attrs)
293 const struct dma_map_ops *ops = get_dma_ops(dev);
295 if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr))
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.
304 WARN_ON(irqs_disabled());
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);
313 ops->free(dev, size, cpu_addr, dma_handle, attrs);
315 EXPORT_SYMBOL(dma_free_attrs);
317 int dma_supported(struct device *dev, u64 mask)
319 const struct dma_map_ops *ops = get_dma_ops(dev);
321 if (dma_is_direct(ops))
322 return dma_direct_supported(dev, mask);
323 if (!ops->dma_supported)
325 return ops->dma_supported(dev, mask);
327 EXPORT_SYMBOL(dma_supported);
329 #ifdef CONFIG_ARCH_HAS_DMA_SET_MASK
330 void arch_dma_set_mask(struct device *dev, u64 mask);
332 #define arch_dma_set_mask(dev, mask) do { } while (0)
335 int dma_set_mask(struct device *dev, u64 mask)
338 * Truncate the mask to the actually supported dma_addr_t width to
339 * avoid generating unsupportable addresses.
341 mask = (dma_addr_t)mask;
343 if (!dev->dma_mask || !dma_supported(dev, mask))
346 arch_dma_set_mask(dev, mask);
347 *dev->dma_mask = mask;
350 EXPORT_SYMBOL(dma_set_mask);
352 #ifndef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK
353 int dma_set_coherent_mask(struct device *dev, u64 mask)
356 * Truncate the mask to the actually supported dma_addr_t width to
357 * avoid generating unsupportable addresses.
359 mask = (dma_addr_t)mask;
361 if (!dma_supported(dev, mask))
364 dev->coherent_dma_mask = mask;
367 EXPORT_SYMBOL(dma_set_coherent_mask);
370 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
371 enum dma_data_direction dir)
373 const struct dma_map_ops *ops = get_dma_ops(dev);
375 BUG_ON(!valid_dma_direction(dir));
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);
382 EXPORT_SYMBOL(dma_cache_sync);
384 size_t dma_max_mapping_size(struct device *dev)
386 const struct dma_map_ops *ops = get_dma_ops(dev);
387 size_t size = SIZE_MAX;
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);
396 EXPORT_SYMBOL_GPL(dma_max_mapping_size);
398 unsigned long dma_get_merge_boundary(struct device *dev)
400 const struct dma_map_ops *ops = get_dma_ops(dev);
402 if (!ops || !ops->get_merge_boundary)
403 return 0; /* can't merge */
405 return ops->get_merge_boundary(dev);
407 EXPORT_SYMBOL_GPL(dma_get_merge_boundary);