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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-arm/dma-mapping.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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diff --git a/include/asm-arm/dma-mapping.h b/include/asm-arm/dma-mapping.h
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1#ifndef ASMARM_DMA_MAPPING_H
2#define ASMARM_DMA_MAPPING_H
3
4#ifdef __KERNEL__
5
6#include <linux/config.h>
7#include <linux/mm.h> /* need struct page */
8
9#include <asm/scatterlist.h>
10
11/*
12 * DMA-consistent mapping functions. These allocate/free a region of
13 * uncached, unwrite-buffered mapped memory space for use with DMA
14 * devices. This is the "generic" version. The PCI specific version
15 * is in pci.h
16 */
17extern void consistent_sync(void *kaddr, size_t size, int rw);
18
19/*
20 * Return whether the given device DMA address mask can be supported
21 * properly. For example, if your device can only drive the low 24-bits
22 * during bus mastering, then you would pass 0x00ffffff as the mask
23 * to this function.
24 */
25static inline int dma_supported(struct device *dev, u64 mask)
26{
27 return dev->dma_mask && *dev->dma_mask != 0;
28}
29
30static inline int dma_set_mask(struct device *dev, u64 dma_mask)
31{
32 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
33 return -EIO;
34
35 *dev->dma_mask = dma_mask;
36
37 return 0;
38}
39
40static inline int dma_get_cache_alignment(void)
41{
42 return 32;
43}
44
45static inline int dma_is_consistent(dma_addr_t handle)
46{
47 return 0;
48}
49
50/*
51 * DMA errors are defined by all-bits-set in the DMA address.
52 */
53static inline int dma_mapping_error(dma_addr_t dma_addr)
54{
55 return dma_addr == ~0;
56}
57
58/**
59 * dma_alloc_coherent - allocate consistent memory for DMA
60 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
61 * @size: required memory size
62 * @handle: bus-specific DMA address
63 *
64 * Allocate some uncached, unbuffered memory for a device for
65 * performing DMA. This function allocates pages, and will
66 * return the CPU-viewed address, and sets @handle to be the
67 * device-viewed address.
68 */
69extern void *
70dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, int gfp);
71
72/**
73 * dma_free_coherent - free memory allocated by dma_alloc_coherent
74 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
75 * @size: size of memory originally requested in dma_alloc_coherent
76 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
77 * @handle: device-view address returned from dma_alloc_coherent
78 *
79 * Free (and unmap) a DMA buffer previously allocated by
80 * dma_alloc_coherent().
81 *
82 * References to memory and mappings associated with cpu_addr/handle
83 * during and after this call executing are illegal.
84 */
85extern void
86dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
87 dma_addr_t handle);
88
89/**
90 * dma_mmap_coherent - map a coherent DMA allocation into user space
91 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
92 * @vma: vm_area_struct describing requested user mapping
93 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
94 * @handle: device-view address returned from dma_alloc_coherent
95 * @size: size of memory originally requested in dma_alloc_coherent
96 *
97 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
98 * into user space. The coherent DMA buffer must not be freed by the
99 * driver until the user space mapping has been released.
100 */
101int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
102 void *cpu_addr, dma_addr_t handle, size_t size);
103
104
105/**
106 * dma_alloc_writecombine - allocate writecombining memory for DMA
107 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
108 * @size: required memory size
109 * @handle: bus-specific DMA address
110 *
111 * Allocate some uncached, buffered memory for a device for
112 * performing DMA. This function allocates pages, and will
113 * return the CPU-viewed address, and sets @handle to be the
114 * device-viewed address.
115 */
116extern void *
117dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, int gfp);
118
119#define dma_free_writecombine(dev,size,cpu_addr,handle) \
120 dma_free_coherent(dev,size,cpu_addr,handle)
121
122int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
123 void *cpu_addr, dma_addr_t handle, size_t size);
124
125
126/**
127 * dma_map_single - map a single buffer for streaming DMA
128 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
129 * @cpu_addr: CPU direct mapped address of buffer
130 * @size: size of buffer to map
131 * @dir: DMA transfer direction
132 *
133 * Ensure that any data held in the cache is appropriately discarded
134 * or written back.
135 *
136 * The device owns this memory once this call has completed. The CPU
137 * can regain ownership by calling dma_unmap_single() or
138 * dma_sync_single_for_cpu().
139 */
140#ifndef CONFIG_DMABOUNCE
141static inline dma_addr_t
142dma_map_single(struct device *dev, void *cpu_addr, size_t size,
143 enum dma_data_direction dir)
144{
145 consistent_sync(cpu_addr, size, dir);
146 return virt_to_dma(dev, (unsigned long)cpu_addr);
147}
148#else
149extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
150#endif
151
152/**
153 * dma_map_page - map a portion of a page for streaming DMA
154 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
155 * @page: page that buffer resides in
156 * @offset: offset into page for start of buffer
157 * @size: size of buffer to map
158 * @dir: DMA transfer direction
159 *
160 * Ensure that any data held in the cache is appropriately discarded
161 * or written back.
162 *
163 * The device owns this memory once this call has completed. The CPU
164 * can regain ownership by calling dma_unmap_page() or
165 * dma_sync_single_for_cpu().
166 */
167static inline dma_addr_t
168dma_map_page(struct device *dev, struct page *page,
169 unsigned long offset, size_t size,
170 enum dma_data_direction dir)
171{
172 return dma_map_single(dev, page_address(page) + offset, size, (int)dir);
173}
174
175/**
176 * dma_unmap_single - unmap a single buffer previously mapped
177 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
178 * @handle: DMA address of buffer
179 * @size: size of buffer to map
180 * @dir: DMA transfer direction
181 *
182 * Unmap a single streaming mode DMA translation. The handle and size
183 * must match what was provided in the previous dma_map_single() call.
184 * All other usages are undefined.
185 *
186 * After this call, reads by the CPU to the buffer are guaranteed to see
187 * whatever the device wrote there.
188 */
189#ifndef CONFIG_DMABOUNCE
190static inline void
191dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
192 enum dma_data_direction dir)
193{
194 /* nothing to do */
195}
196#else
197extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
198#endif
199
200/**
201 * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
202 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
203 * @handle: DMA address of buffer
204 * @size: size of buffer to map
205 * @dir: DMA transfer direction
206 *
207 * Unmap a single streaming mode DMA translation. The handle and size
208 * must match what was provided in the previous dma_map_single() call.
209 * All other usages are undefined.
210 *
211 * After this call, reads by the CPU to the buffer are guaranteed to see
212 * whatever the device wrote there.
213 */
214static inline void
215dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
216 enum dma_data_direction dir)
217{
218 dma_unmap_single(dev, handle, size, (int)dir);
219}
220
221/**
222 * dma_map_sg - map a set of SG buffers for streaming mode DMA
223 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
224 * @sg: list of buffers
225 * @nents: number of buffers to map
226 * @dir: DMA transfer direction
227 *
228 * Map a set of buffers described by scatterlist in streaming
229 * mode for DMA. This is the scatter-gather version of the
230 * above dma_map_single interface. Here the scatter gather list
231 * elements are each tagged with the appropriate dma address
232 * and length. They are obtained via sg_dma_{address,length}(SG).
233 *
234 * NOTE: An implementation may be able to use a smaller number of
235 * DMA address/length pairs than there are SG table elements.
236 * (for example via virtual mapping capabilities)
237 * The routine returns the number of addr/length pairs actually
238 * used, at most nents.
239 *
240 * Device ownership issues as mentioned above for dma_map_single are
241 * the same here.
242 */
243#ifndef CONFIG_DMABOUNCE
244static inline int
245dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
246 enum dma_data_direction dir)
247{
248 int i;
249
250 for (i = 0; i < nents; i++, sg++) {
251 char *virt;
252
253 sg->dma_address = page_to_dma(dev, sg->page) + sg->offset;
254 virt = page_address(sg->page) + sg->offset;
255 consistent_sync(virt, sg->length, dir);
256 }
257
258 return nents;
259}
260#else
261extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
262#endif
263
264/**
265 * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
266 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
267 * @sg: list of buffers
268 * @nents: number of buffers to map
269 * @dir: DMA transfer direction
270 *
271 * Unmap a set of streaming mode DMA translations.
272 * Again, CPU read rules concerning calls here are the same as for
273 * dma_unmap_single() above.
274 */
275#ifndef CONFIG_DMABOUNCE
276static inline void
277dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
278 enum dma_data_direction dir)
279{
280
281 /* nothing to do */
282}
283#else
284extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
285#endif
286
287
288/**
289 * dma_sync_single_for_cpu
290 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
291 * @handle: DMA address of buffer
292 * @size: size of buffer to map
293 * @dir: DMA transfer direction
294 *
295 * Make physical memory consistent for a single streaming mode DMA
296 * translation after a transfer.
297 *
298 * If you perform a dma_map_single() but wish to interrogate the
299 * buffer using the cpu, yet do not wish to teardown the PCI dma
300 * mapping, you must call this function before doing so. At the
301 * next point you give the PCI dma address back to the card, you
302 * must first the perform a dma_sync_for_device, and then the
303 * device again owns the buffer.
304 */
305#ifndef CONFIG_DMABOUNCE
306static inline void
307dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
308 enum dma_data_direction dir)
309{
310 consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
311}
312
313static inline void
314dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
315 enum dma_data_direction dir)
316{
317 consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
318}
319#else
320extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
321extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
322#endif
323
324
325/**
326 * dma_sync_sg_for_cpu
327 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
328 * @sg: list of buffers
329 * @nents: number of buffers to map
330 * @dir: DMA transfer direction
331 *
332 * Make physical memory consistent for a set of streaming
333 * mode DMA translations after a transfer.
334 *
335 * The same as dma_sync_single_for_* but for a scatter-gather list,
336 * same rules and usage.
337 */
338#ifndef CONFIG_DMABOUNCE
339static inline void
340dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
341 enum dma_data_direction dir)
342{
343 int i;
344
345 for (i = 0; i < nents; i++, sg++) {
346 char *virt = page_address(sg->page) + sg->offset;
347 consistent_sync(virt, sg->length, dir);
348 }
349}
350
351static inline void
352dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
353 enum dma_data_direction dir)
354{
355 int i;
356
357 for (i = 0; i < nents; i++, sg++) {
358 char *virt = page_address(sg->page) + sg->offset;
359 consistent_sync(virt, sg->length, dir);
360 }
361}
362#else
363extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
364extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
365#endif
366
367#ifdef CONFIG_DMABOUNCE
368/*
369 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
370 * and utilize bounce buffers as needed to work around limited DMA windows.
371 *
372 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
373 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
374 * On some ADI engineering sytems, PCI inbound window is 32MB (12MB total RAM)
375 *
376 * The following are helper functions used by the dmabounce subystem
377 *
378 */
379
380/**
381 * dmabounce_register_dev
382 *
383 * @dev: valid struct device pointer
384 * @small_buf_size: size of buffers to use with small buffer pool
385 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
386 *
387 * This function should be called by low-level platform code to register
388 * a device as requireing DMA buffer bouncing. The function will allocate
389 * appropriate DMA pools for the device.
390 *
391 */
392extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);
393
394/**
395 * dmabounce_unregister_dev
396 *
397 * @dev: valid struct device pointer
398 *
399 * This function should be called by low-level platform code when device
400 * that was previously registered with dmabounce_register_dev is removed
401 * from the system.
402 *
403 */
404extern void dmabounce_unregister_dev(struct device *);
405
406/**
407 * dma_needs_bounce
408 *
409 * @dev: valid struct device pointer
410 * @dma_handle: dma_handle of unbounced buffer
411 * @size: size of region being mapped
412 *
413 * Platforms that utilize the dmabounce mechanism must implement
414 * this function.
415 *
416 * The dmabounce routines call this function whenever a dma-mapping
417 * is requested to determine whether a given buffer needs to be bounced
418 * or not. The function must return 0 if the the buffer is OK for
419 * DMA access and 1 if the buffer needs to be bounced.
420 *
421 */
422extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
423#endif /* CONFIG_DMABOUNCE */
424
425#endif /* __KERNEL__ */
426#endif