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)__virt_to_bus((unsigned long)page_address(page));
23 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
25 return (void *)__bus_to_virt(addr);
28 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
30 return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
33 static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
35 return __arch_page_to_dma(dev, page);
38 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
40 return __arch_dma_to_virt(dev, addr);
43 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
45 return __arch_virt_to_dma(dev, addr);
50 * DMA-consistent mapping functions. These allocate/free a region of
51 * uncached, unwrite-buffered mapped memory space for use with DMA
52 * devices. This is the "generic" version. The PCI specific version
55 * Note: Drivers should NOT use this function directly, as it will break
56 * platforms with CONFIG_DMABOUNCE.
57 * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
59 extern void dma_cache_maint(const void *kaddr, size_t size, int rw);
62 * Return whether the given device DMA address mask can be supported
63 * properly. For example, if your device can only drive the low 24-bits
64 * during bus mastering, then you would pass 0x00ffffff as the mask
67 * FIXME: This should really be a platform specific issue - we should
68 * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
70 static inline int dma_supported(struct device *dev, u64 mask)
72 return dev->dma_mask && *dev->dma_mask != 0;
75 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
77 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
80 *dev->dma_mask = dma_mask;
85 static inline int dma_get_cache_alignment(void)
90 static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
92 return !!arch_is_coherent();
96 * DMA errors are defined by all-bits-set in the DMA address.
98 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
100 return dma_addr == ~0;
104 * Dummy noncoherent implementation. We don't provide a dma_cache_sync
105 * function so drivers using this API are highlighted with build warnings.
107 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
108 dma_addr_t *handle, gfp_t gfp)
113 static inline void dma_free_noncoherent(struct device *dev, size_t size,
114 void *cpu_addr, dma_addr_t handle)
119 * dma_alloc_coherent - allocate consistent memory for DMA
120 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
121 * @size: required memory size
122 * @handle: bus-specific DMA address
124 * Allocate some uncached, unbuffered memory for a device for
125 * performing DMA. This function allocates pages, and will
126 * return the CPU-viewed address, and sets @handle to be the
127 * device-viewed address.
129 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
132 * dma_free_coherent - free memory allocated by dma_alloc_coherent
133 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
134 * @size: size of memory originally requested in dma_alloc_coherent
135 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
136 * @handle: device-view address returned from dma_alloc_coherent
138 * Free (and unmap) a DMA buffer previously allocated by
139 * dma_alloc_coherent().
141 * References to memory and mappings associated with cpu_addr/handle
142 * during and after this call executing are illegal.
144 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
147 * dma_mmap_coherent - map a coherent DMA allocation into user space
148 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
149 * @vma: vm_area_struct describing requested user mapping
150 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
151 * @handle: device-view address returned from dma_alloc_coherent
152 * @size: size of memory originally requested in dma_alloc_coherent
154 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
155 * into user space. The coherent DMA buffer must not be freed by the
156 * driver until the user space mapping has been released.
158 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
159 void *, dma_addr_t, size_t);
163 * dma_alloc_writecombine - allocate writecombining memory for DMA
164 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
165 * @size: required memory size
166 * @handle: bus-specific DMA address
168 * Allocate some uncached, buffered memory for a device for
169 * performing DMA. This function allocates pages, and will
170 * return the CPU-viewed address, and sets @handle to be the
171 * device-viewed address.
173 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
176 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
177 dma_free_coherent(dev,size,cpu_addr,handle)
179 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
180 void *, dma_addr_t, size_t);
183 #ifdef CONFIG_DMABOUNCE
185 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
186 * and utilize bounce buffers as needed to work around limited DMA windows.
188 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
189 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
190 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
192 * The following are helper functions used by the dmabounce subystem
197 * dmabounce_register_dev
199 * @dev: valid struct device pointer
200 * @small_buf_size: size of buffers to use with small buffer pool
201 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
203 * This function should be called by low-level platform code to register
204 * a device as requireing DMA buffer bouncing. The function will allocate
205 * appropriate DMA pools for the device.
208 extern int dmabounce_register_dev(struct device *, unsigned long,
212 * dmabounce_unregister_dev
214 * @dev: valid struct device pointer
216 * This function should be called by low-level platform code when device
217 * that was previously registered with dmabounce_register_dev is removed
221 extern void dmabounce_unregister_dev(struct device *);
226 * @dev: valid struct device pointer
227 * @dma_handle: dma_handle of unbounced buffer
228 * @size: size of region being mapped
230 * Platforms that utilize the dmabounce mechanism must implement
233 * The dmabounce routines call this function whenever a dma-mapping
234 * is requested to determine whether a given buffer needs to be bounced
235 * or not. The function must return 0 if the buffer is OK for
236 * DMA access and 1 if the buffer needs to be bounced.
239 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
242 * The DMA API, implemented by dmabounce.c. See below for descriptions.
244 extern dma_addr_t dma_map_single(struct device *, void *, size_t,
245 enum dma_data_direction);
246 extern dma_addr_t dma_map_page(struct device *, struct page *,
247 unsigned long, size_t, enum dma_data_direction);
248 extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
249 enum dma_data_direction);
254 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
255 size_t, enum dma_data_direction);
256 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
257 size_t, enum dma_data_direction);
259 #define dmabounce_sync_for_cpu(dev,dma,off,sz,dir) (1)
260 #define dmabounce_sync_for_device(dev,dma,off,sz,dir) (1)
264 * dma_map_single - map a single buffer for streaming DMA
265 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
266 * @cpu_addr: CPU direct mapped address of buffer
267 * @size: size of buffer to map
268 * @dir: DMA transfer direction
270 * Ensure that any data held in the cache is appropriately discarded
273 * The device owns this memory once this call has completed. The CPU
274 * can regain ownership by calling dma_unmap_single() or
275 * dma_sync_single_for_cpu().
277 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
278 size_t size, enum dma_data_direction dir)
280 BUG_ON(!valid_dma_direction(dir));
282 if (!arch_is_coherent())
283 dma_cache_maint(cpu_addr, size, dir);
285 return virt_to_dma(dev, cpu_addr);
289 * dma_map_page - map a portion of a page for streaming DMA
290 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
291 * @page: page that buffer resides in
292 * @offset: offset into page for start of buffer
293 * @size: size of buffer to map
294 * @dir: DMA transfer direction
296 * Ensure that any data held in the cache is appropriately discarded
299 * The device owns this memory once this call has completed. The CPU
300 * can regain ownership by calling dma_unmap_page().
302 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
303 unsigned long offset, size_t size, enum dma_data_direction dir)
305 BUG_ON(!valid_dma_direction(dir));
307 if (!arch_is_coherent())
308 dma_cache_maint(page_address(page) + offset, size, dir);
310 return page_to_dma(dev, page) + offset;
314 * dma_unmap_single - unmap a single buffer previously mapped
315 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
316 * @handle: DMA address of buffer
317 * @size: size of buffer (same as passed to dma_map_single)
318 * @dir: DMA transfer direction (same as passed to dma_map_single)
320 * Unmap a single streaming mode DMA translation. The handle and size
321 * must match what was provided in the previous dma_map_single() call.
322 * All other usages are undefined.
324 * After this call, reads by the CPU to the buffer are guaranteed to see
325 * whatever the device wrote there.
327 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
328 size_t size, enum dma_data_direction dir)
332 #endif /* CONFIG_DMABOUNCE */
335 * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
336 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
337 * @handle: DMA address of buffer
338 * @size: size of buffer (same as passed to dma_map_page)
339 * @dir: DMA transfer direction (same as passed to dma_map_page)
341 * Unmap a page streaming mode DMA translation. The handle and size
342 * must match what was provided in the previous dma_map_page() call.
343 * All other usages are undefined.
345 * After this call, reads by the CPU to the buffer are guaranteed to see
346 * whatever the device wrote there.
348 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
349 size_t size, enum dma_data_direction dir)
351 dma_unmap_single(dev, handle, size, dir);
355 * dma_sync_single_range_for_cpu
356 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
357 * @handle: DMA address of buffer
358 * @offset: offset of region to start sync
359 * @size: size of region to sync
360 * @dir: DMA transfer direction (same as passed to dma_map_single)
362 * Make physical memory consistent for a single streaming mode DMA
363 * translation after a transfer.
365 * If you perform a dma_map_single() but wish to interrogate the
366 * buffer using the cpu, yet do not wish to teardown the PCI dma
367 * mapping, you must call this function before doing so. At the
368 * next point you give the PCI dma address back to the card, you
369 * must first the perform a dma_sync_for_device, and then the
370 * device again owns the buffer.
372 static inline void dma_sync_single_range_for_cpu(struct device *dev,
373 dma_addr_t handle, unsigned long offset, size_t size,
374 enum dma_data_direction dir)
376 BUG_ON(!valid_dma_direction(dir));
378 dmabounce_sync_for_cpu(dev, handle, offset, size, dir);
381 static inline void dma_sync_single_range_for_device(struct device *dev,
382 dma_addr_t handle, unsigned long offset, size_t size,
383 enum dma_data_direction dir)
385 BUG_ON(!valid_dma_direction(dir));
387 if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
390 if (!arch_is_coherent())
391 dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
394 static inline void dma_sync_single_for_cpu(struct device *dev,
395 dma_addr_t handle, size_t size, enum dma_data_direction dir)
397 dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
400 static inline void dma_sync_single_for_device(struct device *dev,
401 dma_addr_t handle, size_t size, enum dma_data_direction dir)
403 dma_sync_single_range_for_device(dev, handle, 0, size, dir);
407 * The scatter list versions of the above methods.
409 extern int dma_map_sg(struct device *, struct scatterlist *, int,
410 enum dma_data_direction);
411 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
412 enum dma_data_direction);
413 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
414 enum dma_data_direction);
415 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
416 enum dma_data_direction);
419 #endif /* __KERNEL__ */