Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * arch/arm/common/dmabounce.c | |
3 | * | |
4 | * Special dma_{map/unmap/dma_sync}_* routines for systems that have | |
5 | * limited DMA windows. These functions utilize bounce buffers to | |
6 | * copy data to/from buffers located outside the DMA region. This | |
7 | * only works for systems in which DMA memory is at the bottom of | |
3a2916aa | 8 | * RAM, the remainder of memory is at the top and the DMA memory |
1da177e4 LT |
9 | * can be marked as ZONE_DMA. Anything beyond that such as discontigous |
10 | * DMA windows will require custom implementations that reserve memory | |
11 | * areas at early bootup. | |
12 | * | |
13 | * Original version by Brad Parker (brad@heeltoe.com) | |
14 | * Re-written by Christopher Hoover <ch@murgatroid.com> | |
15 | * Made generic by Deepak Saxena <dsaxena@plexity.net> | |
16 | * | |
17 | * Copyright (C) 2002 Hewlett Packard Company. | |
18 | * Copyright (C) 2004 MontaVista Software, Inc. | |
19 | * | |
20 | * This program is free software; you can redistribute it and/or | |
21 | * modify it under the terms of the GNU General Public License | |
22 | * version 2 as published by the Free Software Foundation. | |
23 | */ | |
24 | ||
25 | #include <linux/module.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/device.h> | |
29 | #include <linux/dma-mapping.h> | |
30 | #include <linux/dmapool.h> | |
31 | #include <linux/list.h> | |
32 | ||
14eb75b6 RK |
33 | #include <asm/cacheflush.h> |
34 | ||
1da177e4 | 35 | #undef DEBUG |
1da177e4 | 36 | #undef STATS |
cb7610d0 | 37 | |
1da177e4 LT |
38 | #ifdef STATS |
39 | #define DO_STATS(X) do { X ; } while (0) | |
40 | #else | |
41 | #define DO_STATS(X) do { } while (0) | |
42 | #endif | |
43 | ||
44 | /* ************************************************** */ | |
45 | ||
46 | struct safe_buffer { | |
47 | struct list_head node; | |
48 | ||
49 | /* original request */ | |
50 | void *ptr; | |
51 | size_t size; | |
52 | int direction; | |
53 | ||
54 | /* safe buffer info */ | |
cb7610d0 | 55 | struct dmabounce_pool *pool; |
1da177e4 LT |
56 | void *safe; |
57 | dma_addr_t safe_dma_addr; | |
58 | }; | |
59 | ||
cb7610d0 RK |
60 | struct dmabounce_pool { |
61 | unsigned long size; | |
62 | struct dma_pool *pool; | |
63 | #ifdef STATS | |
64 | unsigned long allocs; | |
65 | #endif | |
66 | }; | |
67 | ||
1da177e4 LT |
68 | struct dmabounce_device_info { |
69 | struct list_head node; | |
70 | ||
71 | struct device *dev; | |
1da177e4 | 72 | struct list_head safe_buffers; |
1da177e4 | 73 | #ifdef STATS |
1da177e4 LT |
74 | unsigned long total_allocs; |
75 | unsigned long map_op_count; | |
76 | unsigned long bounce_count; | |
77 | #endif | |
cb7610d0 RK |
78 | struct dmabounce_pool small; |
79 | struct dmabounce_pool large; | |
823588c1 KH |
80 | |
81 | rwlock_t lock; | |
1da177e4 LT |
82 | }; |
83 | ||
84 | static LIST_HEAD(dmabounce_devs); | |
85 | ||
86 | #ifdef STATS | |
87 | static void print_alloc_stats(struct dmabounce_device_info *device_info) | |
88 | { | |
89 | printk(KERN_INFO | |
90 | "%s: dmabounce: sbp: %lu, lbp: %lu, other: %lu, total: %lu\n", | |
91 | device_info->dev->bus_id, | |
cb7610d0 RK |
92 | device_info->small.allocs, device_info->large.allocs, |
93 | device_info->total_allocs - device_info->small.allocs - | |
94 | device_info->large.allocs, | |
1da177e4 LT |
95 | device_info->total_allocs); |
96 | } | |
97 | #endif | |
98 | ||
99 | /* find the given device in the dmabounce device list */ | |
100 | static inline struct dmabounce_device_info * | |
101 | find_dmabounce_dev(struct device *dev) | |
102 | { | |
b46a58fd | 103 | struct dmabounce_device_info *d; |
1da177e4 | 104 | |
b46a58fd | 105 | list_for_each_entry(d, &dmabounce_devs, node) |
1da177e4 LT |
106 | if (d->dev == dev) |
107 | return d; | |
b46a58fd | 108 | |
1da177e4 LT |
109 | return NULL; |
110 | } | |
111 | ||
112 | ||
113 | /* allocate a 'safe' buffer and keep track of it */ | |
114 | static inline struct safe_buffer * | |
115 | alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr, | |
cb7610d0 | 116 | size_t size, enum dma_data_direction dir) |
1da177e4 LT |
117 | { |
118 | struct safe_buffer *buf; | |
cb7610d0 | 119 | struct dmabounce_pool *pool; |
1da177e4 | 120 | struct device *dev = device_info->dev; |
823588c1 | 121 | unsigned long flags; |
1da177e4 LT |
122 | |
123 | dev_dbg(dev, "%s(ptr=%p, size=%d, dir=%d)\n", | |
124 | __func__, ptr, size, dir); | |
125 | ||
cb7610d0 RK |
126 | if (size <= device_info->small.size) { |
127 | pool = &device_info->small; | |
128 | } else if (size <= device_info->large.size) { | |
129 | pool = &device_info->large; | |
130 | } else { | |
131 | pool = NULL; | |
132 | } | |
1da177e4 LT |
133 | |
134 | buf = kmalloc(sizeof(struct safe_buffer), GFP_ATOMIC); | |
135 | if (buf == NULL) { | |
136 | dev_warn(dev, "%s: kmalloc failed\n", __func__); | |
137 | return NULL; | |
138 | } | |
139 | ||
cb7610d0 RK |
140 | buf->ptr = ptr; |
141 | buf->size = size; | |
142 | buf->direction = dir; | |
143 | buf->pool = pool; | |
1da177e4 | 144 | |
cb7610d0 RK |
145 | if (pool) { |
146 | buf->safe = dma_pool_alloc(pool->pool, GFP_ATOMIC, | |
147 | &buf->safe_dma_addr); | |
1da177e4 | 148 | } else { |
cb7610d0 RK |
149 | buf->safe = dma_alloc_coherent(dev, size, &buf->safe_dma_addr, |
150 | GFP_ATOMIC); | |
1da177e4 LT |
151 | } |
152 | ||
cb7610d0 RK |
153 | if (buf->safe == NULL) { |
154 | dev_warn(dev, | |
155 | "%s: could not alloc dma memory (size=%d)\n", | |
156 | __func__, size); | |
1da177e4 LT |
157 | kfree(buf); |
158 | return NULL; | |
159 | } | |
160 | ||
161 | #ifdef STATS | |
cb7610d0 RK |
162 | if (pool) |
163 | pool->allocs++; | |
164 | device_info->total_allocs++; | |
1da177e4 LT |
165 | if (device_info->total_allocs % 1000 == 0) |
166 | print_alloc_stats(device_info); | |
167 | #endif | |
168 | ||
823588c1 KH |
169 | write_lock_irqsave(&device_info->lock, flags); |
170 | ||
1da177e4 LT |
171 | list_add(&buf->node, &device_info->safe_buffers); |
172 | ||
823588c1 KH |
173 | write_unlock_irqrestore(&device_info->lock, flags); |
174 | ||
1da177e4 LT |
175 | return buf; |
176 | } | |
177 | ||
178 | /* determine if a buffer is from our "safe" pool */ | |
179 | static inline struct safe_buffer * | |
180 | find_safe_buffer(struct dmabounce_device_info *device_info, dma_addr_t safe_dma_addr) | |
181 | { | |
e2785f0d | 182 | struct safe_buffer *b, *rb = NULL; |
823588c1 KH |
183 | unsigned long flags; |
184 | ||
185 | read_lock_irqsave(&device_info->lock, flags); | |
1da177e4 | 186 | |
b46a58fd | 187 | list_for_each_entry(b, &device_info->safe_buffers, node) |
e2785f0d KH |
188 | if (b->safe_dma_addr == safe_dma_addr) { |
189 | rb = b; | |
823588c1 | 190 | break; |
e2785f0d | 191 | } |
1da177e4 | 192 | |
823588c1 | 193 | read_unlock_irqrestore(&device_info->lock, flags); |
e2785f0d | 194 | return rb; |
1da177e4 LT |
195 | } |
196 | ||
197 | static inline void | |
198 | free_safe_buffer(struct dmabounce_device_info *device_info, struct safe_buffer *buf) | |
199 | { | |
823588c1 KH |
200 | unsigned long flags; |
201 | ||
1da177e4 LT |
202 | dev_dbg(device_info->dev, "%s(buf=%p)\n", __func__, buf); |
203 | ||
823588c1 KH |
204 | write_lock_irqsave(&device_info->lock, flags); |
205 | ||
1da177e4 LT |
206 | list_del(&buf->node); |
207 | ||
823588c1 KH |
208 | write_unlock_irqrestore(&device_info->lock, flags); |
209 | ||
1da177e4 | 210 | if (buf->pool) |
cb7610d0 | 211 | dma_pool_free(buf->pool->pool, buf->safe, buf->safe_dma_addr); |
1da177e4 LT |
212 | else |
213 | dma_free_coherent(device_info->dev, buf->size, buf->safe, | |
214 | buf->safe_dma_addr); | |
215 | ||
216 | kfree(buf); | |
217 | } | |
218 | ||
219 | /* ************************************************** */ | |
220 | ||
221 | #ifdef STATS | |
1da177e4 LT |
222 | static void print_map_stats(struct dmabounce_device_info *device_info) |
223 | { | |
cb7610d0 RK |
224 | dev_info(device_info->dev, |
225 | "dmabounce: map_op_count=%lu, bounce_count=%lu\n", | |
1da177e4 LT |
226 | device_info->map_op_count, device_info->bounce_count); |
227 | } | |
228 | #endif | |
229 | ||
230 | static inline dma_addr_t | |
231 | map_single(struct device *dev, void *ptr, size_t size, | |
232 | enum dma_data_direction dir) | |
233 | { | |
234 | struct dmabounce_device_info *device_info = find_dmabounce_dev(dev); | |
235 | dma_addr_t dma_addr; | |
236 | int needs_bounce = 0; | |
237 | ||
238 | if (device_info) | |
239 | DO_STATS ( device_info->map_op_count++ ); | |
240 | ||
241 | dma_addr = virt_to_dma(dev, ptr); | |
242 | ||
243 | if (dev->dma_mask) { | |
244 | unsigned long mask = *dev->dma_mask; | |
245 | unsigned long limit; | |
246 | ||
247 | limit = (mask + 1) & ~mask; | |
248 | if (limit && size > limit) { | |
249 | dev_err(dev, "DMA mapping too big (requested %#x " | |
250 | "mask %#Lx)\n", size, *dev->dma_mask); | |
251 | return ~0; | |
252 | } | |
253 | ||
254 | /* | |
255 | * Figure out if we need to bounce from the DMA mask. | |
256 | */ | |
257 | needs_bounce = (dma_addr | (dma_addr + size - 1)) & ~mask; | |
258 | } | |
259 | ||
260 | if (device_info && (needs_bounce || dma_needs_bounce(dev, dma_addr, size))) { | |
261 | struct safe_buffer *buf; | |
262 | ||
263 | buf = alloc_safe_buffer(device_info, ptr, size, dir); | |
264 | if (buf == 0) { | |
265 | dev_err(dev, "%s: unable to map unsafe buffer %p!\n", | |
266 | __func__, ptr); | |
267 | return 0; | |
268 | } | |
269 | ||
270 | dev_dbg(dev, | |
271 | "%s: unsafe buffer %p (phy=%p) mapped to %p (phy=%p)\n", | |
272 | __func__, buf->ptr, (void *) virt_to_dma(dev, buf->ptr), | |
273 | buf->safe, (void *) buf->safe_dma_addr); | |
274 | ||
275 | if ((dir == DMA_TO_DEVICE) || | |
276 | (dir == DMA_BIDIRECTIONAL)) { | |
277 | dev_dbg(dev, "%s: copy unsafe %p to safe %p, size %d\n", | |
278 | __func__, ptr, buf->safe, size); | |
279 | memcpy(buf->safe, ptr, size); | |
280 | } | |
cb7610d0 | 281 | ptr = buf->safe; |
1da177e4 LT |
282 | |
283 | dma_addr = buf->safe_dma_addr; | |
1da177e4 LT |
284 | } |
285 | ||
cb7610d0 RK |
286 | consistent_sync(ptr, size, dir); |
287 | ||
1da177e4 LT |
288 | return dma_addr; |
289 | } | |
290 | ||
291 | static inline void | |
292 | unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size, | |
293 | enum dma_data_direction dir) | |
294 | { | |
295 | struct dmabounce_device_info *device_info = find_dmabounce_dev(dev); | |
296 | struct safe_buffer *buf = NULL; | |
297 | ||
298 | /* | |
299 | * Trying to unmap an invalid mapping | |
300 | */ | |
cb7610d0 | 301 | if (dma_mapping_error(dma_addr)) { |
1da177e4 LT |
302 | dev_err(dev, "Trying to unmap invalid mapping\n"); |
303 | return; | |
304 | } | |
305 | ||
306 | if (device_info) | |
307 | buf = find_safe_buffer(device_info, dma_addr); | |
308 | ||
309 | if (buf) { | |
310 | BUG_ON(buf->size != size); | |
311 | ||
312 | dev_dbg(dev, | |
313 | "%s: unsafe buffer %p (phy=%p) mapped to %p (phy=%p)\n", | |
314 | __func__, buf->ptr, (void *) virt_to_dma(dev, buf->ptr), | |
315 | buf->safe, (void *) buf->safe_dma_addr); | |
316 | ||
1da177e4 LT |
317 | DO_STATS ( device_info->bounce_count++ ); |
318 | ||
5abc100e RK |
319 | if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) { |
320 | unsigned long ptr; | |
321 | ||
1da177e4 LT |
322 | dev_dbg(dev, |
323 | "%s: copy back safe %p to unsafe %p size %d\n", | |
324 | __func__, buf->safe, buf->ptr, size); | |
325 | memcpy(buf->ptr, buf->safe, size); | |
5abc100e RK |
326 | |
327 | /* | |
328 | * DMA buffers must have the same cache properties | |
329 | * as if they were really used for DMA - which means | |
330 | * data must be written back to RAM. Note that | |
331 | * we don't use dmac_flush_range() here for the | |
332 | * bidirectional case because we know the cache | |
333 | * lines will be coherent with the data written. | |
334 | */ | |
335 | ptr = (unsigned long)buf->ptr; | |
336 | dmac_clean_range(ptr, ptr + size); | |
1da177e4 LT |
337 | } |
338 | free_safe_buffer(device_info, buf); | |
339 | } | |
340 | } | |
341 | ||
342 | static inline void | |
343 | sync_single(struct device *dev, dma_addr_t dma_addr, size_t size, | |
344 | enum dma_data_direction dir) | |
345 | { | |
346 | struct dmabounce_device_info *device_info = find_dmabounce_dev(dev); | |
347 | struct safe_buffer *buf = NULL; | |
348 | ||
349 | if (device_info) | |
350 | buf = find_safe_buffer(device_info, dma_addr); | |
351 | ||
352 | if (buf) { | |
353 | /* | |
354 | * Both of these checks from original code need to be | |
355 | * commented out b/c some drivers rely on the following: | |
356 | * | |
357 | * 1) Drivers may map a large chunk of memory into DMA space | |
358 | * but only sync a small portion of it. Good example is | |
359 | * allocating a large buffer, mapping it, and then | |
360 | * breaking it up into small descriptors. No point | |
361 | * in syncing the whole buffer if you only have to | |
362 | * touch one descriptor. | |
363 | * | |
364 | * 2) Buffers that are mapped as DMA_BIDIRECTIONAL are | |
365 | * usually only synced in one dir at a time. | |
366 | * | |
367 | * See drivers/net/eepro100.c for examples of both cases. | |
368 | * | |
369 | * -ds | |
370 | * | |
371 | * BUG_ON(buf->size != size); | |
372 | * BUG_ON(buf->direction != dir); | |
373 | */ | |
374 | ||
375 | dev_dbg(dev, | |
376 | "%s: unsafe buffer %p (phy=%p) mapped to %p (phy=%p)\n", | |
377 | __func__, buf->ptr, (void *) virt_to_dma(dev, buf->ptr), | |
378 | buf->safe, (void *) buf->safe_dma_addr); | |
379 | ||
380 | DO_STATS ( device_info->bounce_count++ ); | |
381 | ||
382 | switch (dir) { | |
383 | case DMA_FROM_DEVICE: | |
384 | dev_dbg(dev, | |
385 | "%s: copy back safe %p to unsafe %p size %d\n", | |
386 | __func__, buf->safe, buf->ptr, size); | |
387 | memcpy(buf->ptr, buf->safe, size); | |
388 | break; | |
389 | case DMA_TO_DEVICE: | |
390 | dev_dbg(dev, | |
391 | "%s: copy out unsafe %p to safe %p, size %d\n", | |
392 | __func__,buf->ptr, buf->safe, size); | |
393 | memcpy(buf->safe, buf->ptr, size); | |
394 | break; | |
395 | case DMA_BIDIRECTIONAL: | |
396 | BUG(); /* is this allowed? what does it mean? */ | |
397 | default: | |
398 | BUG(); | |
399 | } | |
400 | consistent_sync(buf->safe, size, dir); | |
401 | } else { | |
402 | consistent_sync(dma_to_virt(dev, dma_addr), size, dir); | |
403 | } | |
404 | } | |
405 | ||
406 | /* ************************************************** */ | |
407 | ||
408 | /* | |
409 | * see if a buffer address is in an 'unsafe' range. if it is | |
410 | * allocate a 'safe' buffer and copy the unsafe buffer into it. | |
411 | * substitute the safe buffer for the unsafe one. | |
412 | * (basically move the buffer from an unsafe area to a safe one) | |
413 | */ | |
414 | dma_addr_t | |
415 | dma_map_single(struct device *dev, void *ptr, size_t size, | |
416 | enum dma_data_direction dir) | |
417 | { | |
1da177e4 LT |
418 | dma_addr_t dma_addr; |
419 | ||
420 | dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n", | |
421 | __func__, ptr, size, dir); | |
422 | ||
423 | BUG_ON(dir == DMA_NONE); | |
424 | ||
1da177e4 LT |
425 | dma_addr = map_single(dev, ptr, size, dir); |
426 | ||
1da177e4 LT |
427 | return dma_addr; |
428 | } | |
429 | ||
430 | /* | |
431 | * see if a mapped address was really a "safe" buffer and if so, copy | |
432 | * the data from the safe buffer back to the unsafe buffer and free up | |
433 | * the safe buffer. (basically return things back to the way they | |
434 | * should be) | |
435 | */ | |
436 | ||
437 | void | |
438 | dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size, | |
439 | enum dma_data_direction dir) | |
440 | { | |
1da177e4 LT |
441 | dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n", |
442 | __func__, (void *) dma_addr, size, dir); | |
443 | ||
444 | BUG_ON(dir == DMA_NONE); | |
445 | ||
1da177e4 | 446 | unmap_single(dev, dma_addr, size, dir); |
1da177e4 LT |
447 | } |
448 | ||
449 | int | |
450 | dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, | |
451 | enum dma_data_direction dir) | |
452 | { | |
1da177e4 LT |
453 | int i; |
454 | ||
455 | dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n", | |
456 | __func__, sg, nents, dir); | |
457 | ||
458 | BUG_ON(dir == DMA_NONE); | |
459 | ||
1da177e4 LT |
460 | for (i = 0; i < nents; i++, sg++) { |
461 | struct page *page = sg->page; | |
462 | unsigned int offset = sg->offset; | |
463 | unsigned int length = sg->length; | |
464 | void *ptr = page_address(page) + offset; | |
465 | ||
466 | sg->dma_address = | |
467 | map_single(dev, ptr, length, dir); | |
468 | } | |
469 | ||
1da177e4 LT |
470 | return nents; |
471 | } | |
472 | ||
473 | void | |
474 | dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, | |
475 | enum dma_data_direction dir) | |
476 | { | |
1da177e4 LT |
477 | int i; |
478 | ||
479 | dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n", | |
480 | __func__, sg, nents, dir); | |
481 | ||
482 | BUG_ON(dir == DMA_NONE); | |
483 | ||
1da177e4 LT |
484 | for (i = 0; i < nents; i++, sg++) { |
485 | dma_addr_t dma_addr = sg->dma_address; | |
486 | unsigned int length = sg->length; | |
487 | ||
488 | unmap_single(dev, dma_addr, length, dir); | |
489 | } | |
1da177e4 LT |
490 | } |
491 | ||
492 | void | |
493 | dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr, size_t size, | |
494 | enum dma_data_direction dir) | |
495 | { | |
1da177e4 LT |
496 | dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n", |
497 | __func__, (void *) dma_addr, size, dir); | |
498 | ||
1da177e4 | 499 | sync_single(dev, dma_addr, size, dir); |
1da177e4 LT |
500 | } |
501 | ||
502 | void | |
503 | dma_sync_single_for_device(struct device *dev, dma_addr_t dma_addr, size_t size, | |
504 | enum dma_data_direction dir) | |
505 | { | |
1da177e4 LT |
506 | dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n", |
507 | __func__, (void *) dma_addr, size, dir); | |
508 | ||
1da177e4 | 509 | sync_single(dev, dma_addr, size, dir); |
1da177e4 LT |
510 | } |
511 | ||
512 | void | |
513 | dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents, | |
514 | enum dma_data_direction dir) | |
515 | { | |
1da177e4 LT |
516 | int i; |
517 | ||
518 | dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n", | |
519 | __func__, sg, nents, dir); | |
520 | ||
521 | BUG_ON(dir == DMA_NONE); | |
522 | ||
1da177e4 LT |
523 | for (i = 0; i < nents; i++, sg++) { |
524 | dma_addr_t dma_addr = sg->dma_address; | |
525 | unsigned int length = sg->length; | |
526 | ||
527 | sync_single(dev, dma_addr, length, dir); | |
528 | } | |
1da177e4 LT |
529 | } |
530 | ||
531 | void | |
532 | dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, | |
533 | enum dma_data_direction dir) | |
534 | { | |
1da177e4 LT |
535 | int i; |
536 | ||
537 | dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n", | |
538 | __func__, sg, nents, dir); | |
539 | ||
540 | BUG_ON(dir == DMA_NONE); | |
541 | ||
1da177e4 LT |
542 | for (i = 0; i < nents; i++, sg++) { |
543 | dma_addr_t dma_addr = sg->dma_address; | |
544 | unsigned int length = sg->length; | |
545 | ||
546 | sync_single(dev, dma_addr, length, dir); | |
547 | } | |
1da177e4 LT |
548 | } |
549 | ||
cb7610d0 RK |
550 | static int |
551 | dmabounce_init_pool(struct dmabounce_pool *pool, struct device *dev, const char *name, | |
552 | unsigned long size) | |
553 | { | |
554 | pool->size = size; | |
555 | DO_STATS(pool->allocs = 0); | |
556 | pool->pool = dma_pool_create(name, dev, size, | |
557 | 0 /* byte alignment */, | |
558 | 0 /* no page-crossing issues */); | |
559 | ||
560 | return pool->pool ? 0 : -ENOMEM; | |
561 | } | |
562 | ||
1da177e4 LT |
563 | int |
564 | dmabounce_register_dev(struct device *dev, unsigned long small_buffer_size, | |
565 | unsigned long large_buffer_size) | |
566 | { | |
567 | struct dmabounce_device_info *device_info; | |
cb7610d0 | 568 | int ret; |
1da177e4 LT |
569 | |
570 | device_info = kmalloc(sizeof(struct dmabounce_device_info), GFP_ATOMIC); | |
571 | if (!device_info) { | |
572 | printk(KERN_ERR | |
573 | "Could not allocated dmabounce_device_info for %s", | |
574 | dev->bus_id); | |
575 | return -ENOMEM; | |
576 | } | |
577 | ||
cb7610d0 RK |
578 | ret = dmabounce_init_pool(&device_info->small, dev, |
579 | "small_dmabounce_pool", small_buffer_size); | |
580 | if (ret) { | |
581 | dev_err(dev, | |
582 | "dmabounce: could not allocate DMA pool for %ld byte objects\n", | |
583 | small_buffer_size); | |
584 | goto err_free; | |
1da177e4 LT |
585 | } |
586 | ||
587 | if (large_buffer_size) { | |
cb7610d0 RK |
588 | ret = dmabounce_init_pool(&device_info->large, dev, |
589 | "large_dmabounce_pool", | |
590 | large_buffer_size); | |
591 | if (ret) { | |
592 | dev_err(dev, | |
593 | "dmabounce: could not allocate DMA pool for %ld byte objects\n", | |
594 | large_buffer_size); | |
595 | goto err_destroy; | |
1da177e4 LT |
596 | } |
597 | } | |
598 | ||
599 | device_info->dev = dev; | |
1da177e4 | 600 | INIT_LIST_HEAD(&device_info->safe_buffers); |
823588c1 | 601 | rwlock_init(&device_info->lock); |
1da177e4 LT |
602 | |
603 | #ifdef STATS | |
1da177e4 LT |
604 | device_info->total_allocs = 0; |
605 | device_info->map_op_count = 0; | |
606 | device_info->bounce_count = 0; | |
607 | #endif | |
608 | ||
609 | list_add(&device_info->node, &dmabounce_devs); | |
610 | ||
611 | printk(KERN_INFO "dmabounce: registered device %s on %s bus\n", | |
612 | dev->bus_id, dev->bus->name); | |
613 | ||
614 | return 0; | |
cb7610d0 RK |
615 | |
616 | err_destroy: | |
617 | dma_pool_destroy(device_info->small.pool); | |
618 | err_free: | |
619 | kfree(device_info); | |
620 | return ret; | |
1da177e4 LT |
621 | } |
622 | ||
623 | void | |
624 | dmabounce_unregister_dev(struct device *dev) | |
625 | { | |
626 | struct dmabounce_device_info *device_info = find_dmabounce_dev(dev); | |
627 | ||
628 | if (!device_info) { | |
629 | printk(KERN_WARNING | |
630 | "%s: Never registered with dmabounce but attempting" \ | |
631 | "to unregister!\n", dev->bus_id); | |
632 | return; | |
633 | } | |
634 | ||
635 | if (!list_empty(&device_info->safe_buffers)) { | |
636 | printk(KERN_ERR | |
637 | "%s: Removing from dmabounce with pending buffers!\n", | |
638 | dev->bus_id); | |
639 | BUG(); | |
640 | } | |
641 | ||
cb7610d0 RK |
642 | if (device_info->small.pool) |
643 | dma_pool_destroy(device_info->small.pool); | |
644 | if (device_info->large.pool) | |
645 | dma_pool_destroy(device_info->large.pool); | |
1da177e4 LT |
646 | |
647 | #ifdef STATS | |
648 | print_alloc_stats(device_info); | |
649 | print_map_stats(device_info); | |
650 | #endif | |
651 | ||
652 | list_del(&device_info->node); | |
653 | ||
654 | kfree(device_info); | |
655 | ||
656 | printk(KERN_INFO "dmabounce: device %s on %s bus unregistered\n", | |
657 | dev->bus_id, dev->bus->name); | |
658 | } | |
659 | ||
660 | ||
661 | EXPORT_SYMBOL(dma_map_single); | |
662 | EXPORT_SYMBOL(dma_unmap_single); | |
663 | EXPORT_SYMBOL(dma_map_sg); | |
664 | EXPORT_SYMBOL(dma_unmap_sg); | |
73218187 KH |
665 | EXPORT_SYMBOL(dma_sync_single_for_cpu); |
666 | EXPORT_SYMBOL(dma_sync_single_for_device); | |
1da177e4 LT |
667 | EXPORT_SYMBOL(dma_sync_sg); |
668 | EXPORT_SYMBOL(dmabounce_register_dev); | |
669 | EXPORT_SYMBOL(dmabounce_unregister_dev); | |
670 | ||
671 | MODULE_AUTHOR("Christopher Hoover <ch@hpl.hp.com>, Deepak Saxena <dsaxena@plexity.net>"); | |
672 | MODULE_DESCRIPTION("Special dma_{map/unmap/dma_sync}_* routines for systems with limited DMA windows"); | |
673 | MODULE_LICENSE("GPL"); |