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 #ifdef CONFIG_DMABOUNCE
132 if (dev->archdata.dmabounce) {
133 if (dma_mask >= ISA_DMA_THRESHOLD)
139 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
142 *dev->dma_mask = dma_mask;
147 static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
149 return !!arch_is_coherent();
153 * DMA errors are defined by all-bits-set in the DMA address.
155 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
157 return dma_addr == ~0;
161 * Dummy noncoherent implementation. We don't provide a dma_cache_sync
162 * function so drivers using this API are highlighted with build warnings.
164 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
165 dma_addr_t *handle, gfp_t gfp)
170 static inline void dma_free_noncoherent(struct device *dev, size_t size,
171 void *cpu_addr, dma_addr_t handle)
176 * dma_alloc_coherent - allocate consistent memory for DMA
177 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
178 * @size: required memory size
179 * @handle: bus-specific DMA address
181 * Allocate some uncached, unbuffered memory for a device for
182 * performing DMA. This function allocates pages, and will
183 * return the CPU-viewed address, and sets @handle to be the
184 * device-viewed address.
186 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
189 * dma_free_coherent - free memory allocated by dma_alloc_coherent
190 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
191 * @size: size of memory originally requested in dma_alloc_coherent
192 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
193 * @handle: device-view address returned from dma_alloc_coherent
195 * Free (and unmap) a DMA buffer previously allocated by
196 * dma_alloc_coherent().
198 * References to memory and mappings associated with cpu_addr/handle
199 * during and after this call executing are illegal.
201 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
204 * dma_mmap_coherent - map a coherent DMA allocation into user space
205 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
206 * @vma: vm_area_struct describing requested user mapping
207 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
208 * @handle: device-view address returned from dma_alloc_coherent
209 * @size: size of memory originally requested in dma_alloc_coherent
211 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
212 * into user space. The coherent DMA buffer must not be freed by the
213 * driver until the user space mapping has been released.
215 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
216 void *, dma_addr_t, size_t);
220 * dma_alloc_writecombine - allocate writecombining memory for DMA
221 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
222 * @size: required memory size
223 * @handle: bus-specific DMA address
225 * Allocate some uncached, buffered memory for a device for
226 * performing DMA. This function allocates pages, and will
227 * return the CPU-viewed address, and sets @handle to be the
228 * device-viewed address.
230 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
233 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
234 dma_free_coherent(dev,size,cpu_addr,handle)
236 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
237 void *, dma_addr_t, size_t);
240 #ifdef CONFIG_DMABOUNCE
242 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
243 * and utilize bounce buffers as needed to work around limited DMA windows.
245 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
246 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
247 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
249 * The following are helper functions used by the dmabounce subystem
254 * dmabounce_register_dev
256 * @dev: valid struct device pointer
257 * @small_buf_size: size of buffers to use with small buffer pool
258 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
260 * This function should be called by low-level platform code to register
261 * a device as requireing DMA buffer bouncing. The function will allocate
262 * appropriate DMA pools for the device.
265 extern int dmabounce_register_dev(struct device *, unsigned long,
269 * dmabounce_unregister_dev
271 * @dev: valid struct device pointer
273 * This function should be called by low-level platform code when device
274 * that was previously registered with dmabounce_register_dev is removed
278 extern void dmabounce_unregister_dev(struct device *);
283 * @dev: valid struct device pointer
284 * @dma_handle: dma_handle of unbounced buffer
285 * @size: size of region being mapped
287 * Platforms that utilize the dmabounce mechanism must implement
290 * The dmabounce routines call this function whenever a dma-mapping
291 * is requested to determine whether a given buffer needs to be bounced
292 * or not. The function must return 0 if the buffer is OK for
293 * DMA access and 1 if the buffer needs to be bounced.
296 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
299 * The DMA API, implemented by dmabounce.c. See below for descriptions.
301 extern dma_addr_t dma_map_single(struct device *, void *, size_t,
302 enum dma_data_direction);
303 extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
304 enum dma_data_direction);
305 extern dma_addr_t dma_map_page(struct device *, struct page *,
306 unsigned long, size_t, enum dma_data_direction);
307 extern void dma_unmap_page(struct device *, dma_addr_t, size_t,
308 enum dma_data_direction);
313 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
314 size_t, enum dma_data_direction);
315 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
316 size_t, enum dma_data_direction);
318 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
319 unsigned long offset, size_t size, enum dma_data_direction dir)
324 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
325 unsigned long offset, size_t size, enum dma_data_direction dir)
332 * dma_map_single - map a single buffer for streaming DMA
333 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
334 * @cpu_addr: CPU direct mapped address of buffer
335 * @size: size of buffer to map
336 * @dir: DMA transfer direction
338 * Ensure that any data held in the cache is appropriately discarded
341 * The device owns this memory once this call has completed. The CPU
342 * can regain ownership by calling dma_unmap_single() or
343 * dma_sync_single_for_cpu().
345 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
346 size_t size, enum dma_data_direction dir)
348 BUG_ON(!valid_dma_direction(dir));
350 __dma_single_cpu_to_dev(cpu_addr, size, dir);
352 return virt_to_dma(dev, cpu_addr);
356 * dma_map_page - map a portion of a page for streaming DMA
357 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
358 * @page: page that buffer resides in
359 * @offset: offset into page for start of buffer
360 * @size: size of buffer to map
361 * @dir: DMA transfer direction
363 * Ensure that any data held in the cache is appropriately discarded
366 * The device owns this memory once this call has completed. The CPU
367 * can regain ownership by calling dma_unmap_page().
369 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
370 unsigned long offset, size_t size, enum dma_data_direction dir)
372 BUG_ON(!valid_dma_direction(dir));
374 __dma_page_cpu_to_dev(page, offset, size, dir);
376 return page_to_dma(dev, page) + offset;
380 * dma_unmap_single - unmap a single buffer previously mapped
381 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
382 * @handle: DMA address of buffer
383 * @size: size of buffer (same as passed to dma_map_single)
384 * @dir: DMA transfer direction (same as passed to dma_map_single)
386 * Unmap a single streaming mode DMA translation. The handle and size
387 * must match what was provided in the previous dma_map_single() call.
388 * All other usages are undefined.
390 * After this call, reads by the CPU to the buffer are guaranteed to see
391 * whatever the device wrote there.
393 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
394 size_t size, enum dma_data_direction dir)
396 __dma_single_dev_to_cpu(dma_to_virt(dev, handle), size, dir);
400 * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
401 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
402 * @handle: DMA address of buffer
403 * @size: size of buffer (same as passed to dma_map_page)
404 * @dir: DMA transfer direction (same as passed to dma_map_page)
406 * Unmap a page streaming mode DMA translation. The handle and size
407 * must match what was provided in the previous dma_map_page() call.
408 * All other usages are undefined.
410 * After this call, reads by the CPU to the buffer are guaranteed to see
411 * whatever the device wrote there.
413 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
414 size_t size, enum dma_data_direction dir)
416 __dma_page_dev_to_cpu(dma_to_page(dev, handle), handle & ~PAGE_MASK,
419 #endif /* CONFIG_DMABOUNCE */
422 * dma_sync_single_range_for_cpu
423 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
424 * @handle: DMA address of buffer
425 * @offset: offset of region to start sync
426 * @size: size of region to sync
427 * @dir: DMA transfer direction (same as passed to dma_map_single)
429 * Make physical memory consistent for a single streaming mode DMA
430 * translation after a transfer.
432 * If you perform a dma_map_single() but wish to interrogate the
433 * buffer using the cpu, yet do not wish to teardown the PCI dma
434 * mapping, you must call this function before doing so. At the
435 * next point you give the PCI dma address back to the card, you
436 * must first the perform a dma_sync_for_device, and then the
437 * device again owns the buffer.
439 static inline void dma_sync_single_range_for_cpu(struct device *dev,
440 dma_addr_t handle, unsigned long offset, size_t size,
441 enum dma_data_direction dir)
443 BUG_ON(!valid_dma_direction(dir));
445 if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
448 __dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
451 static inline void dma_sync_single_range_for_device(struct device *dev,
452 dma_addr_t handle, unsigned long offset, size_t size,
453 enum dma_data_direction dir)
455 BUG_ON(!valid_dma_direction(dir));
457 if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
460 __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
463 static inline void dma_sync_single_for_cpu(struct device *dev,
464 dma_addr_t handle, size_t size, enum dma_data_direction dir)
466 dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
469 static inline void dma_sync_single_for_device(struct device *dev,
470 dma_addr_t handle, size_t size, enum dma_data_direction dir)
472 dma_sync_single_range_for_device(dev, handle, 0, size, dir);
476 * The scatter list versions of the above methods.
478 extern int dma_map_sg(struct device *, struct scatterlist *, int,
479 enum dma_data_direction);
480 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
481 enum dma_data_direction);
482 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
483 enum dma_data_direction);
484 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
485 enum dma_data_direction);
488 #endif /* __KERNEL__ */