1 #ifndef ASMARM_DMA_MAPPING_H
2 #define ASMARM_DMA_MAPPING_H
6 #include <linux/mm_types.h>
7 #include <linux/scatterlist.h>
9 #include <asm-generic/dma-coherent.h>
10 #include <asm/memory.h>
13 * page_to_dma/dma_to_virt/virt_to_dma are architecture private functions
14 * used internally by the DMA-mapping API to provide DMA addresses. They
15 * must not be used by drivers.
17 #ifndef __arch_page_to_dma
18 static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
20 return (dma_addr_t)__pfn_to_bus(page_to_pfn(page));
23 static inline struct page *dma_to_page(struct device *dev, dma_addr_t addr)
25 return pfn_to_page(__bus_to_pfn(addr));
28 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
30 return (void *)__bus_to_virt(addr);
33 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
35 return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
38 static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
40 return __arch_page_to_dma(dev, page);
43 static inline struct page *dma_to_page(struct device *dev, dma_addr_t addr)
45 return __arch_dma_to_page(dev, addr);
48 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
50 return __arch_dma_to_virt(dev, addr);
53 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
55 return __arch_virt_to_dma(dev, addr);
60 * The DMA API is built upon the notion of "buffer ownership". A buffer
61 * is either exclusively owned by the CPU (and therefore may be accessed
62 * by it) or exclusively owned by the DMA device. These helper functions
63 * represent the transitions between these two ownership states.
65 * Note, however, that on later ARMs, this notion does not work due to
66 * speculative prefetches. We model our approach on the assumption that
67 * the CPU does do speculative prefetches, which means we clean caches
68 * before transfers and delay cache invalidation until transfer completion.
70 * Private support functions: these are not part of the API and are
71 * liable to change. Drivers must not use these.
73 static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size,
74 enum dma_data_direction dir)
76 extern void ___dma_single_cpu_to_dev(const void *, size_t,
77 enum dma_data_direction);
79 if (!arch_is_coherent())
80 ___dma_single_cpu_to_dev(kaddr, size, dir);
83 static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size,
84 enum dma_data_direction dir)
86 extern void ___dma_single_dev_to_cpu(const void *, size_t,
87 enum dma_data_direction);
89 if (!arch_is_coherent())
90 ___dma_single_dev_to_cpu(kaddr, size, dir);
93 static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
94 size_t size, enum dma_data_direction dir)
96 extern void ___dma_page_cpu_to_dev(struct page *, unsigned long,
97 size_t, enum dma_data_direction);
99 if (!arch_is_coherent())
100 ___dma_page_cpu_to_dev(page, off, size, dir);
103 static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
104 size_t size, enum dma_data_direction dir)
106 extern void ___dma_page_dev_to_cpu(struct page *, unsigned long,
107 size_t, enum dma_data_direction);
109 if (!arch_is_coherent())
110 ___dma_page_dev_to_cpu(page, off, size, dir);
114 * Return whether the given device DMA address mask can be supported
115 * properly. For example, if your device can only drive the low 24-bits
116 * during bus mastering, then you would pass 0x00ffffff as the mask
119 * FIXME: This should really be a platform specific issue - we should
120 * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
122 static inline int dma_supported(struct device *dev, u64 mask)
124 if (mask < ISA_DMA_THRESHOLD)
129 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
131 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
134 *dev->dma_mask = dma_mask;
139 static inline int dma_get_cache_alignment(void)
144 static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
146 return !!arch_is_coherent();
150 * DMA errors are defined by all-bits-set in the DMA address.
152 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
154 return dma_addr == ~0;
158 * Dummy noncoherent implementation. We don't provide a dma_cache_sync
159 * function so drivers using this API are highlighted with build warnings.
161 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
162 dma_addr_t *handle, gfp_t gfp)
167 static inline void dma_free_noncoherent(struct device *dev, size_t size,
168 void *cpu_addr, dma_addr_t handle)
173 * dma_alloc_coherent - allocate consistent memory for DMA
174 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
175 * @size: required memory size
176 * @handle: bus-specific DMA address
178 * Allocate some uncached, unbuffered memory for a device for
179 * performing DMA. This function allocates pages, and will
180 * return the CPU-viewed address, and sets @handle to be the
181 * device-viewed address.
183 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
186 * dma_free_coherent - free memory allocated by dma_alloc_coherent
187 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
188 * @size: size of memory originally requested in dma_alloc_coherent
189 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
190 * @handle: device-view address returned from dma_alloc_coherent
192 * Free (and unmap) a DMA buffer previously allocated by
193 * dma_alloc_coherent().
195 * References to memory and mappings associated with cpu_addr/handle
196 * during and after this call executing are illegal.
198 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
201 * dma_mmap_coherent - map a coherent DMA allocation into user space
202 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
203 * @vma: vm_area_struct describing requested user mapping
204 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
205 * @handle: device-view address returned from dma_alloc_coherent
206 * @size: size of memory originally requested in dma_alloc_coherent
208 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
209 * into user space. The coherent DMA buffer must not be freed by the
210 * driver until the user space mapping has been released.
212 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
213 void *, dma_addr_t, size_t);
217 * dma_alloc_writecombine - allocate writecombining memory for DMA
218 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
219 * @size: required memory size
220 * @handle: bus-specific DMA address
222 * Allocate some uncached, buffered memory for a device for
223 * performing DMA. This function allocates pages, and will
224 * return the CPU-viewed address, and sets @handle to be the
225 * device-viewed address.
227 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
230 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
231 dma_free_coherent(dev,size,cpu_addr,handle)
233 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
234 void *, dma_addr_t, size_t);
237 #ifdef CONFIG_DMABOUNCE
239 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
240 * and utilize bounce buffers as needed to work around limited DMA windows.
242 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
243 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
244 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
246 * The following are helper functions used by the dmabounce subystem
251 * dmabounce_register_dev
253 * @dev: valid struct device pointer
254 * @small_buf_size: size of buffers to use with small buffer pool
255 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
257 * This function should be called by low-level platform code to register
258 * a device as requireing DMA buffer bouncing. The function will allocate
259 * appropriate DMA pools for the device.
262 extern int dmabounce_register_dev(struct device *, unsigned long,
266 * dmabounce_unregister_dev
268 * @dev: valid struct device pointer
270 * This function should be called by low-level platform code when device
271 * that was previously registered with dmabounce_register_dev is removed
275 extern void dmabounce_unregister_dev(struct device *);
280 * @dev: valid struct device pointer
281 * @dma_handle: dma_handle of unbounced buffer
282 * @size: size of region being mapped
284 * Platforms that utilize the dmabounce mechanism must implement
287 * The dmabounce routines call this function whenever a dma-mapping
288 * is requested to determine whether a given buffer needs to be bounced
289 * or not. The function must return 0 if the buffer is OK for
290 * DMA access and 1 if the buffer needs to be bounced.
293 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
296 * The DMA API, implemented by dmabounce.c. See below for descriptions.
298 extern dma_addr_t dma_map_single(struct device *, void *, size_t,
299 enum dma_data_direction);
300 extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
301 enum dma_data_direction);
302 extern dma_addr_t dma_map_page(struct device *, struct page *,
303 unsigned long, size_t, enum dma_data_direction);
304 extern void dma_unmap_page(struct device *, dma_addr_t, size_t,
305 enum dma_data_direction);
310 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
311 size_t, enum dma_data_direction);
312 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
313 size_t, enum dma_data_direction);
315 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
316 unsigned long offset, size_t size, enum dma_data_direction dir)
321 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
322 unsigned long offset, size_t size, enum dma_data_direction dir)
329 * dma_map_single - map a single buffer for streaming DMA
330 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
331 * @cpu_addr: CPU direct mapped address of buffer
332 * @size: size of buffer to map
333 * @dir: DMA transfer direction
335 * Ensure that any data held in the cache is appropriately discarded
338 * The device owns this memory once this call has completed. The CPU
339 * can regain ownership by calling dma_unmap_single() or
340 * dma_sync_single_for_cpu().
342 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
343 size_t size, enum dma_data_direction dir)
345 BUG_ON(!valid_dma_direction(dir));
347 __dma_single_cpu_to_dev(cpu_addr, size, dir);
349 return virt_to_dma(dev, cpu_addr);
353 * dma_map_page - map a portion of a page for streaming DMA
354 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
355 * @page: page that buffer resides in
356 * @offset: offset into page for start of buffer
357 * @size: size of buffer to map
358 * @dir: DMA transfer direction
360 * Ensure that any data held in the cache is appropriately discarded
363 * The device owns this memory once this call has completed. The CPU
364 * can regain ownership by calling dma_unmap_page().
366 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
367 unsigned long offset, size_t size, enum dma_data_direction dir)
369 BUG_ON(!valid_dma_direction(dir));
371 __dma_page_cpu_to_dev(page, offset, size, dir);
373 return page_to_dma(dev, page) + offset;
377 * dma_unmap_single - unmap a single buffer previously mapped
378 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
379 * @handle: DMA address of buffer
380 * @size: size of buffer (same as passed to dma_map_single)
381 * @dir: DMA transfer direction (same as passed to dma_map_single)
383 * Unmap a single streaming mode DMA translation. The handle and size
384 * must match what was provided in the previous dma_map_single() call.
385 * All other usages are undefined.
387 * After this call, reads by the CPU to the buffer are guaranteed to see
388 * whatever the device wrote there.
390 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
391 size_t size, enum dma_data_direction dir)
393 __dma_single_dev_to_cpu(dma_to_virt(dev, handle), size, dir);
397 * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
398 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
399 * @handle: DMA address of buffer
400 * @size: size of buffer (same as passed to dma_map_page)
401 * @dir: DMA transfer direction (same as passed to dma_map_page)
403 * Unmap a page streaming mode DMA translation. The handle and size
404 * must match what was provided in the previous dma_map_page() call.
405 * All other usages are undefined.
407 * After this call, reads by the CPU to the buffer are guaranteed to see
408 * whatever the device wrote there.
410 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
411 size_t size, enum dma_data_direction dir)
413 __dma_page_dev_to_cpu(dma_to_page(dev, handle), handle & ~PAGE_MASK,
416 #endif /* CONFIG_DMABOUNCE */
419 * dma_sync_single_range_for_cpu
420 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
421 * @handle: DMA address of buffer
422 * @offset: offset of region to start sync
423 * @size: size of region to sync
424 * @dir: DMA transfer direction (same as passed to dma_map_single)
426 * Make physical memory consistent for a single streaming mode DMA
427 * translation after a transfer.
429 * If you perform a dma_map_single() but wish to interrogate the
430 * buffer using the cpu, yet do not wish to teardown the PCI dma
431 * mapping, you must call this function before doing so. At the
432 * next point you give the PCI dma address back to the card, you
433 * must first the perform a dma_sync_for_device, and then the
434 * device again owns the buffer.
436 static inline void dma_sync_single_range_for_cpu(struct device *dev,
437 dma_addr_t handle, unsigned long offset, size_t size,
438 enum dma_data_direction dir)
440 BUG_ON(!valid_dma_direction(dir));
442 if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
445 __dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
448 static inline void dma_sync_single_range_for_device(struct device *dev,
449 dma_addr_t handle, unsigned long offset, size_t size,
450 enum dma_data_direction dir)
452 BUG_ON(!valid_dma_direction(dir));
454 if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
457 __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
460 static inline void dma_sync_single_for_cpu(struct device *dev,
461 dma_addr_t handle, size_t size, enum dma_data_direction dir)
463 dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
466 static inline void dma_sync_single_for_device(struct device *dev,
467 dma_addr_t handle, size_t size, enum dma_data_direction dir)
469 dma_sync_single_range_for_device(dev, handle, 0, size, dir);
473 * The scatter list versions of the above methods.
475 extern int dma_map_sg(struct device *, struct scatterlist *, int,
476 enum dma_data_direction);
477 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
478 enum dma_data_direction);
479 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
480 enum dma_data_direction);
481 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
482 enum dma_data_direction);
485 #endif /* __KERNEL__ */