ia64/linux-2.6.18-xen.hg

view include/asm-arm/dma-mapping.h @ 782:9ab1c319531f

merge with linux-2.6.18-xen.hg
author Isaku Yamahata <yamahata@valinux.co.jp>
date Wed Jan 28 13:07:23 2009 +0900 (2009-01-28)
parents 831230e53067
children
line source
1 #ifndef ASMARM_DMA_MAPPING_H
2 #define ASMARM_DMA_MAPPING_H
4 #ifdef __KERNEL__
6 #include <linux/mm.h> /* need struct page */
8 #include <asm/scatterlist.h>
10 /*
11 * DMA-consistent mapping functions. These allocate/free a region of
12 * uncached, unwrite-buffered mapped memory space for use with DMA
13 * devices. This is the "generic" version. The PCI specific version
14 * is in pci.h
15 */
16 extern void consistent_sync(void *kaddr, size_t size, int rw);
18 /*
19 * Return whether the given device DMA address mask can be supported
20 * properly. For example, if your device can only drive the low 24-bits
21 * during bus mastering, then you would pass 0x00ffffff as the mask
22 * to this function.
23 *
24 * FIXME: This should really be a platform specific issue - we should
25 * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
26 */
27 static inline int dma_supported(struct device *dev, u64 mask)
28 {
29 return dev->dma_mask && *dev->dma_mask != 0;
30 }
32 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
33 {
34 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
35 return -EIO;
37 *dev->dma_mask = dma_mask;
39 return 0;
40 }
42 static inline int dma_get_cache_alignment(void)
43 {
44 return 32;
45 }
47 static inline int dma_is_consistent(dma_addr_t handle)
48 {
49 return !!arch_is_coherent();
50 }
52 /*
53 * DMA errors are defined by all-bits-set in the DMA address.
54 */
55 static inline int dma_mapping_error(dma_addr_t dma_addr)
56 {
57 return dma_addr == ~0;
58 }
60 /**
61 * dma_alloc_coherent - allocate consistent memory for DMA
62 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
63 * @size: required memory size
64 * @handle: bus-specific DMA address
65 *
66 * Allocate some uncached, unbuffered memory for a device for
67 * performing DMA. This function allocates pages, and will
68 * return the CPU-viewed address, and sets @handle to be the
69 * device-viewed address.
70 */
71 extern void *
72 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
74 /**
75 * dma_free_coherent - free memory allocated by dma_alloc_coherent
76 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
77 * @size: size of memory originally requested in dma_alloc_coherent
78 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
79 * @handle: device-view address returned from dma_alloc_coherent
80 *
81 * Free (and unmap) a DMA buffer previously allocated by
82 * dma_alloc_coherent().
83 *
84 * References to memory and mappings associated with cpu_addr/handle
85 * during and after this call executing are illegal.
86 */
87 extern void
88 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
89 dma_addr_t handle);
91 /**
92 * dma_mmap_coherent - map a coherent DMA allocation into user space
93 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
94 * @vma: vm_area_struct describing requested user mapping
95 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
96 * @handle: device-view address returned from dma_alloc_coherent
97 * @size: size of memory originally requested in dma_alloc_coherent
98 *
99 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
100 * into user space. The coherent DMA buffer must not be freed by the
101 * driver until the user space mapping has been released.
102 */
103 int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
104 void *cpu_addr, dma_addr_t handle, size_t size);
107 /**
108 * dma_alloc_writecombine - allocate writecombining memory for DMA
109 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
110 * @size: required memory size
111 * @handle: bus-specific DMA address
112 *
113 * Allocate some uncached, buffered memory for a device for
114 * performing DMA. This function allocates pages, and will
115 * return the CPU-viewed address, and sets @handle to be the
116 * device-viewed address.
117 */
118 extern void *
119 dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
121 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
122 dma_free_coherent(dev,size,cpu_addr,handle)
124 int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
125 void *cpu_addr, dma_addr_t handle, size_t size);
128 /**
129 * dma_map_single - map a single buffer for streaming DMA
130 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
131 * @cpu_addr: CPU direct mapped address of buffer
132 * @size: size of buffer to map
133 * @dir: DMA transfer direction
134 *
135 * Ensure that any data held in the cache is appropriately discarded
136 * or written back.
137 *
138 * The device owns this memory once this call has completed. The CPU
139 * can regain ownership by calling dma_unmap_single() or
140 * dma_sync_single_for_cpu().
141 */
142 #ifndef CONFIG_DMABOUNCE
143 static inline dma_addr_t
144 dma_map_single(struct device *dev, void *cpu_addr, size_t size,
145 enum dma_data_direction dir)
146 {
147 if (!arch_is_coherent())
148 consistent_sync(cpu_addr, size, dir);
150 return virt_to_dma(dev, (unsigned long)cpu_addr);
151 }
152 #else
153 extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
154 #endif
156 /**
157 * dma_map_page - map a portion of a page for streaming DMA
158 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
159 * @page: page that buffer resides in
160 * @offset: offset into page for start of buffer
161 * @size: size of buffer to map
162 * @dir: DMA transfer direction
163 *
164 * Ensure that any data held in the cache is appropriately discarded
165 * or written back.
166 *
167 * The device owns this memory once this call has completed. The CPU
168 * can regain ownership by calling dma_unmap_page() or
169 * dma_sync_single_for_cpu().
170 */
171 static inline dma_addr_t
172 dma_map_page(struct device *dev, struct page *page,
173 unsigned long offset, size_t size,
174 enum dma_data_direction dir)
175 {
176 return dma_map_single(dev, page_address(page) + offset, size, (int)dir);
177 }
179 /**
180 * dma_unmap_single - unmap a single buffer previously mapped
181 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
182 * @handle: DMA address of buffer
183 * @size: size of buffer to map
184 * @dir: DMA transfer direction
185 *
186 * Unmap a single streaming mode DMA translation. The handle and size
187 * must match what was provided in the previous dma_map_single() call.
188 * All other usages are undefined.
189 *
190 * After this call, reads by the CPU to the buffer are guaranteed to see
191 * whatever the device wrote there.
192 */
193 #ifndef CONFIG_DMABOUNCE
194 static inline void
195 dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
196 enum dma_data_direction dir)
197 {
198 /* nothing to do */
199 }
200 #else
201 extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
202 #endif
204 /**
205 * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
206 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
207 * @handle: DMA address of buffer
208 * @size: size of buffer to map
209 * @dir: DMA transfer direction
210 *
211 * Unmap a single streaming mode DMA translation. The handle and size
212 * must match what was provided in the previous dma_map_single() call.
213 * All other usages are undefined.
214 *
215 * After this call, reads by the CPU to the buffer are guaranteed to see
216 * whatever the device wrote there.
217 */
218 static inline void
219 dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
220 enum dma_data_direction dir)
221 {
222 dma_unmap_single(dev, handle, size, (int)dir);
223 }
225 /**
226 * dma_map_sg - map a set of SG buffers for streaming mode DMA
227 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
228 * @sg: list of buffers
229 * @nents: number of buffers to map
230 * @dir: DMA transfer direction
231 *
232 * Map a set of buffers described by scatterlist in streaming
233 * mode for DMA. This is the scatter-gather version of the
234 * above dma_map_single interface. Here the scatter gather list
235 * elements are each tagged with the appropriate dma address
236 * and length. They are obtained via sg_dma_{address,length}(SG).
237 *
238 * NOTE: An implementation may be able to use a smaller number of
239 * DMA address/length pairs than there are SG table elements.
240 * (for example via virtual mapping capabilities)
241 * The routine returns the number of addr/length pairs actually
242 * used, at most nents.
243 *
244 * Device ownership issues as mentioned above for dma_map_single are
245 * the same here.
246 */
247 #ifndef CONFIG_DMABOUNCE
248 static inline int
249 dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
250 enum dma_data_direction dir)
251 {
252 int i;
254 for (i = 0; i < nents; i++, sg++) {
255 char *virt;
257 sg->dma_address = page_to_dma(dev, sg->page) + sg->offset;
258 virt = page_address(sg->page) + sg->offset;
260 if (!arch_is_coherent())
261 consistent_sync(virt, sg->length, dir);
262 }
264 return nents;
265 }
266 #else
267 extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
268 #endif
270 /**
271 * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
272 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
273 * @sg: list of buffers
274 * @nents: number of buffers to map
275 * @dir: DMA transfer direction
276 *
277 * Unmap a set of streaming mode DMA translations.
278 * Again, CPU read rules concerning calls here are the same as for
279 * dma_unmap_single() above.
280 */
281 #ifndef CONFIG_DMABOUNCE
282 static inline void
283 dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
284 enum dma_data_direction dir)
285 {
287 /* nothing to do */
288 }
289 #else
290 extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
291 #endif
294 /**
295 * dma_sync_single_for_cpu
296 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
297 * @handle: DMA address of buffer
298 * @size: size of buffer to map
299 * @dir: DMA transfer direction
300 *
301 * Make physical memory consistent for a single streaming mode DMA
302 * translation after a transfer.
303 *
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.
310 */
311 #ifndef CONFIG_DMABOUNCE
312 static inline void
313 dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
314 enum dma_data_direction dir)
315 {
316 if (!arch_is_coherent())
317 consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
318 }
320 static inline void
321 dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
322 enum dma_data_direction dir)
323 {
324 if (!arch_is_coherent())
325 consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
326 }
327 #else
328 extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
329 extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
330 #endif
333 /**
334 * dma_sync_sg_for_cpu
335 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
336 * @sg: list of buffers
337 * @nents: number of buffers to map
338 * @dir: DMA transfer direction
339 *
340 * Make physical memory consistent for a set of streaming
341 * mode DMA translations after a transfer.
342 *
343 * The same as dma_sync_single_for_* but for a scatter-gather list,
344 * same rules and usage.
345 */
346 #ifndef CONFIG_DMABOUNCE
347 static inline void
348 dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
349 enum dma_data_direction dir)
350 {
351 int i;
353 for (i = 0; i < nents; i++, sg++) {
354 char *virt = page_address(sg->page) + sg->offset;
355 if (!arch_is_coherent())
356 consistent_sync(virt, sg->length, dir);
357 }
358 }
360 static inline void
361 dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
362 enum dma_data_direction dir)
363 {
364 int i;
366 for (i = 0; i < nents; i++, sg++) {
367 char *virt = page_address(sg->page) + sg->offset;
368 if (!arch_is_coherent())
369 consistent_sync(virt, sg->length, dir);
370 }
371 }
372 #else
373 extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
374 extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
375 #endif
377 #ifdef CONFIG_DMABOUNCE
378 /*
379 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
380 * and utilize bounce buffers as needed to work around limited DMA windows.
381 *
382 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
383 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
384 * On some ADI engineering sytems, PCI inbound window is 32MB (12MB total RAM)
385 *
386 * The following are helper functions used by the dmabounce subystem
387 *
388 */
390 /**
391 * dmabounce_register_dev
392 *
393 * @dev: valid struct device pointer
394 * @small_buf_size: size of buffers to use with small buffer pool
395 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
396 *
397 * This function should be called by low-level platform code to register
398 * a device as requireing DMA buffer bouncing. The function will allocate
399 * appropriate DMA pools for the device.
400 *
401 */
402 extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);
404 /**
405 * dmabounce_unregister_dev
406 *
407 * @dev: valid struct device pointer
408 *
409 * This function should be called by low-level platform code when device
410 * that was previously registered with dmabounce_register_dev is removed
411 * from the system.
412 *
413 */
414 extern void dmabounce_unregister_dev(struct device *);
416 /**
417 * dma_needs_bounce
418 *
419 * @dev: valid struct device pointer
420 * @dma_handle: dma_handle of unbounced buffer
421 * @size: size of region being mapped
422 *
423 * Platforms that utilize the dmabounce mechanism must implement
424 * this function.
425 *
426 * The dmabounce routines call this function whenever a dma-mapping
427 * is requested to determine whether a given buffer needs to be bounced
428 * or not. The function must return 0 if the the buffer is OK for
429 * DMA access and 1 if the buffer needs to be bounced.
430 *
431 */
432 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
433 #endif /* CONFIG_DMABOUNCE */
435 #endif /* __KERNEL__ */
436 #endif