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.
108 dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
114 dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr,
120 * dma_alloc_coherent - allocate consistent memory for DMA
121 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
122 * @size: required memory size
123 * @handle: bus-specific DMA address
125 * Allocate some uncached, unbuffered memory for a device for
126 * performing DMA. This function allocates pages, and will
127 * return the CPU-viewed address, and sets @handle to be the
128 * device-viewed address.
131 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
134 * dma_free_coherent - free memory allocated by dma_alloc_coherent
135 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
136 * @size: size of memory originally requested in dma_alloc_coherent
137 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
138 * @handle: device-view address returned from dma_alloc_coherent
140 * Free (and unmap) a DMA buffer previously allocated by
141 * dma_alloc_coherent().
143 * References to memory and mappings associated with cpu_addr/handle
144 * during and after this call executing are illegal.
147 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
151 * dma_mmap_coherent - map a coherent DMA allocation into user space
152 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
153 * @vma: vm_area_struct describing requested user mapping
154 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
155 * @handle: device-view address returned from dma_alloc_coherent
156 * @size: size of memory originally requested in dma_alloc_coherent
158 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
159 * into user space. The coherent DMA buffer must not be freed by the
160 * driver until the user space mapping has been released.
162 int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
163 void *cpu_addr, dma_addr_t handle, size_t size);
167 * dma_alloc_writecombine - allocate writecombining memory for DMA
168 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
169 * @size: required memory size
170 * @handle: bus-specific DMA address
172 * Allocate some uncached, buffered memory for a device for
173 * performing DMA. This function allocates pages, and will
174 * return the CPU-viewed address, and sets @handle to be the
175 * device-viewed address.
178 dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
180 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
181 dma_free_coherent(dev,size,cpu_addr,handle)
183 int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
184 void *cpu_addr, dma_addr_t handle, size_t size);
188 * dma_map_single - map a single buffer for streaming DMA
189 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
190 * @cpu_addr: CPU direct mapped address of buffer
191 * @size: size of buffer to map
192 * @dir: DMA transfer direction
194 * Ensure that any data held in the cache is appropriately discarded
197 * The device owns this memory once this call has completed. The CPU
198 * can regain ownership by calling dma_unmap_single() or
199 * dma_sync_single_for_cpu().
201 #ifndef CONFIG_DMABOUNCE
202 static inline dma_addr_t
203 dma_map_single(struct device *dev, void *cpu_addr, size_t size,
204 enum dma_data_direction dir)
206 if (!arch_is_coherent())
207 dma_cache_maint(cpu_addr, size, dir);
209 return virt_to_dma(dev, cpu_addr);
212 extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
216 * dma_map_page - map a portion of a page for streaming DMA
217 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
218 * @page: page that buffer resides in
219 * @offset: offset into page for start of buffer
220 * @size: size of buffer to map
221 * @dir: DMA transfer direction
223 * Ensure that any data held in the cache is appropriately discarded
226 * The device owns this memory once this call has completed. The CPU
227 * can regain ownership by calling dma_unmap_page() or
228 * dma_sync_single_for_cpu().
230 #ifndef CONFIG_DMABOUNCE
231 static inline dma_addr_t
232 dma_map_page(struct device *dev, struct page *page,
233 unsigned long offset, size_t size,
234 enum dma_data_direction dir)
236 if (!arch_is_coherent())
237 dma_cache_maint(page_address(page) + offset, size, dir);
239 return page_to_dma(dev, page) + offset;
242 extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
243 unsigned long offset, size_t size,
244 enum dma_data_direction dir);
248 * dma_unmap_single - unmap a single buffer previously mapped
249 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
250 * @handle: DMA address of buffer
251 * @size: size of buffer to map
252 * @dir: DMA transfer direction
254 * Unmap a single streaming mode DMA translation. The handle and size
255 * must match what was provided in the previous dma_map_single() call.
256 * All other usages are undefined.
258 * After this call, reads by the CPU to the buffer are guaranteed to see
259 * whatever the device wrote there.
261 #ifndef CONFIG_DMABOUNCE
263 dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
264 enum dma_data_direction dir)
269 extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
273 * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
274 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
275 * @handle: DMA address of buffer
276 * @size: size of buffer to map
277 * @dir: DMA transfer direction
279 * Unmap a single streaming mode DMA translation. The handle and size
280 * must match what was provided in the previous dma_map_single() call.
281 * All other usages are undefined.
283 * After this call, reads by the CPU to the buffer are guaranteed to see
284 * whatever the device wrote there.
287 dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
288 enum dma_data_direction dir)
290 dma_unmap_single(dev, handle, size, dir);
294 * dma_sync_single_range_for_cpu
295 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
296 * @handle: DMA address of buffer
297 * @offset: offset of region to start sync
298 * @size: size of region to sync
299 * @dir: DMA transfer direction (same as passed to dma_map_single)
301 * Make physical memory consistent for a single streaming mode DMA
302 * translation after a transfer.
304 * If you perform a dma_map_single() but wish to interrogate the
305 * buffer using the cpu, yet do not wish to teardown the PCI dma
306 * mapping, you must call this function before doing so. At the
307 * next point you give the PCI dma address back to the card, you
308 * must first the perform a dma_sync_for_device, and then the
309 * device again owns the buffer.
311 #ifndef CONFIG_DMABOUNCE
313 dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t handle,
314 unsigned long offset, size_t size,
315 enum dma_data_direction dir)
317 if (!arch_is_coherent())
318 dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
322 dma_sync_single_range_for_device(struct device *dev, dma_addr_t handle,
323 unsigned long offset, size_t size,
324 enum dma_data_direction dir)
326 if (!arch_is_coherent())
327 dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
330 extern void dma_sync_single_range_for_cpu(struct device *, dma_addr_t, unsigned long, size_t, enum dma_data_direction);
331 extern void dma_sync_single_range_for_device(struct device *, dma_addr_t, unsigned long, size_t, enum dma_data_direction);
335 dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
336 enum dma_data_direction dir)
338 dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
342 dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
343 enum dma_data_direction dir)
345 dma_sync_single_range_for_device(dev, handle, 0, size, dir);
349 * The scatter list versions of the above methods.
351 extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
352 extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
353 extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
354 extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
357 #ifdef CONFIG_DMABOUNCE
359 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
360 * and utilize bounce buffers as needed to work around limited DMA windows.
362 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
363 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
364 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
366 * The following are helper functions used by the dmabounce subystem
371 * dmabounce_register_dev
373 * @dev: valid struct device pointer
374 * @small_buf_size: size of buffers to use with small buffer pool
375 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
377 * This function should be called by low-level platform code to register
378 * a device as requireing DMA buffer bouncing. The function will allocate
379 * appropriate DMA pools for the device.
382 extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);
385 * dmabounce_unregister_dev
387 * @dev: valid struct device pointer
389 * This function should be called by low-level platform code when device
390 * that was previously registered with dmabounce_register_dev is removed
394 extern void dmabounce_unregister_dev(struct device *);
399 * @dev: valid struct device pointer
400 * @dma_handle: dma_handle of unbounced buffer
401 * @size: size of region being mapped
403 * Platforms that utilize the dmabounce mechanism must implement
406 * The dmabounce routines call this function whenever a dma-mapping
407 * is requested to determine whether a given buffer needs to be bounced
408 * or not. The function must return 0 if the buffer is OK for
409 * DMA access and 1 if the buffer needs to be bounced.
412 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
413 #endif /* CONFIG_DMABOUNCE */
415 #endif /* __KERNEL__ */