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1 | /* |
2 | * Digital Audio (PCM) abstract layer |
3 | * Copyright (c) by Jaroslav Kysela <perex@perex.cz> |
4 | * |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License as published by |
8 | * the Free Software Foundation; either version 2 of the License, or |
9 | * (at your option) any later version. |
10 | * |
11 | * This program is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | * GNU General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU General Public License |
17 | * along with this program; if not, write to the Free Software |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
19 | * |
20 | */ |
21 | |
22 | #include <asm/io.h> |
23 | #include <linux/time.h> |
24 | #include <linux/init.h> |
25 | #include <linux/slab.h> |
26 | #include <linux/moduleparam.h> |
27 | #include <linux/vmalloc.h> |
28 | #include <sound/core.h> |
29 | #include <sound/pcm.h> |
30 | #include <sound/info.h> |
31 | #include <sound/initval.h> |
32 | |
33 | static int preallocate_dma = 1; |
34 | module_param(preallocate_dma, int, 0444); |
35 | MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized."); |
36 | |
37 | static int maximum_substreams = 4; |
38 | module_param(maximum_substreams, int, 0444); |
39 | MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory."); |
40 | |
41 | static const size_t snd_minimum_buffer = 16384; |
42 | |
43 | |
44 | /* |
45 | * try to allocate as the large pages as possible. |
46 | * stores the resultant memory size in *res_size. |
47 | * |
48 | * the minimum size is snd_minimum_buffer. it should be power of 2. |
49 | */ |
50 | static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size) |
51 | { |
52 | struct snd_dma_buffer *dmab = &substream->dma_buffer; |
53 | int err; |
54 | |
55 | /* already reserved? */ |
56 | if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) { |
57 | if (dmab->bytes >= size) |
58 | return 0; /* yes */ |
59 | /* no, free the reserved block */ |
60 | snd_dma_free_pages(dmab); |
61 | dmab->bytes = 0; |
62 | } |
63 | |
64 | do { |
65 | if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev, |
66 | size, dmab)) < 0) { |
67 | if (err != -ENOMEM) |
68 | return err; /* fatal error */ |
69 | } else |
70 | return 0; |
71 | size >>= 1; |
72 | } while (size >= snd_minimum_buffer); |
73 | dmab->bytes = 0; /* tell error */ |
74 | return 0; |
75 | } |
76 | |
77 | /* |
78 | * release the preallocated buffer if not yet done. |
79 | */ |
80 | static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream) |
81 | { |
82 | if (substream->dma_buffer.area == NULL) |
83 | return; |
84 | if (substream->dma_buf_id) |
85 | snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id); |
86 | else |
87 | snd_dma_free_pages(&substream->dma_buffer); |
88 | substream->dma_buffer.area = NULL; |
89 | } |
90 | |
91 | /** |
92 | * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream. |
93 | * @substream: the pcm substream instance |
94 | * |
95 | * Releases the pre-allocated buffer of the given substream. |
96 | * |
97 | * Returns zero if successful, or a negative error code on failure. |
98 | */ |
99 | int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream) |
100 | { |
101 | snd_pcm_lib_preallocate_dma_free(substream); |
102 | #ifdef CONFIG_SND_VERBOSE_PROCFS |
103 | snd_info_free_entry(substream->proc_prealloc_max_entry); |
104 | substream->proc_prealloc_max_entry = NULL; |
105 | snd_info_free_entry(substream->proc_prealloc_entry); |
106 | substream->proc_prealloc_entry = NULL; |
107 | #endif |
108 | return 0; |
109 | } |
110 | |
111 | /** |
112 | * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm |
113 | * @pcm: the pcm instance |
114 | * |
115 | * Releases all the pre-allocated buffers on the given pcm. |
116 | * |
117 | * Returns zero if successful, or a negative error code on failure. |
118 | */ |
119 | int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm) |
120 | { |
121 | struct snd_pcm_substream *substream; |
122 | int stream; |
123 | |
124 | for (stream = 0; stream < 2; stream++) |
125 | for (substream = pcm->streams[stream].substream; substream; substream = substream->next) |
126 | snd_pcm_lib_preallocate_free(substream); |
127 | return 0; |
128 | } |
129 | |
130 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all); |
131 | |
132 | #ifdef CONFIG_SND_VERBOSE_PROCFS |
133 | /* |
134 | * read callback for prealloc proc file |
135 | * |
136 | * prints the current allocated size in kB. |
137 | */ |
138 | static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry, |
139 | struct snd_info_buffer *buffer) |
140 | { |
141 | struct snd_pcm_substream *substream = entry->private_data; |
142 | snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024); |
143 | } |
144 | |
145 | /* |
146 | * read callback for prealloc_max proc file |
147 | * |
148 | * prints the maximum allowed size in kB. |
149 | */ |
150 | static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry, |
151 | struct snd_info_buffer *buffer) |
152 | { |
153 | struct snd_pcm_substream *substream = entry->private_data; |
154 | snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024); |
155 | } |
156 | |
157 | /* |
158 | * write callback for prealloc proc file |
159 | * |
160 | * accepts the preallocation size in kB. |
161 | */ |
162 | static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry, |
163 | struct snd_info_buffer *buffer) |
164 | { |
165 | struct snd_pcm_substream *substream = entry->private_data; |
166 | char line[64], str[64]; |
167 | size_t size; |
168 | struct snd_dma_buffer new_dmab; |
169 | |
170 | if (substream->runtime) { |
171 | buffer->error = -EBUSY; |
172 | return; |
173 | } |
174 | if (!snd_info_get_line(buffer, line, sizeof(line))) { |
175 | snd_info_get_str(str, line, sizeof(str)); |
176 | size = simple_strtoul(str, NULL, 10) * 1024; |
177 | if ((size != 0 && size < 8192) || size > substream->dma_max) { |
178 | buffer->error = -EINVAL; |
179 | return; |
180 | } |
181 | if (substream->dma_buffer.bytes == size) |
182 | return; |
183 | memset(&new_dmab, 0, sizeof(new_dmab)); |
184 | new_dmab.dev = substream->dma_buffer.dev; |
185 | if (size > 0) { |
186 | if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, |
187 | substream->dma_buffer.dev.dev, |
188 | size, &new_dmab) < 0) { |
189 | buffer->error = -ENOMEM; |
190 | return; |
191 | } |
192 | substream->buffer_bytes_max = size; |
193 | } else { |
194 | substream->buffer_bytes_max = UINT_MAX; |
195 | } |
196 | if (substream->dma_buffer.area) |
197 | snd_dma_free_pages(&substream->dma_buffer); |
198 | substream->dma_buffer = new_dmab; |
199 | } else { |
200 | buffer->error = -EINVAL; |
201 | } |
202 | } |
203 | |
204 | static inline void preallocate_info_init(struct snd_pcm_substream *substream) |
205 | { |
206 | struct snd_info_entry *entry; |
207 | |
208 | if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) { |
209 | entry->c.text.read = snd_pcm_lib_preallocate_proc_read; |
210 | entry->c.text.write = snd_pcm_lib_preallocate_proc_write; |
211 | entry->mode |= S_IWUSR; |
212 | entry->private_data = substream; |
213 | if (snd_info_register(entry) < 0) { |
214 | snd_info_free_entry(entry); |
215 | entry = NULL; |
216 | } |
217 | } |
218 | substream->proc_prealloc_entry = entry; |
219 | if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) { |
220 | entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read; |
221 | entry->private_data = substream; |
222 | if (snd_info_register(entry) < 0) { |
223 | snd_info_free_entry(entry); |
224 | entry = NULL; |
225 | } |
226 | } |
227 | substream->proc_prealloc_max_entry = entry; |
228 | } |
229 | |
230 | #else /* !CONFIG_SND_VERBOSE_PROCFS */ |
231 | #define preallocate_info_init(s) |
232 | #endif /* CONFIG_SND_VERBOSE_PROCFS */ |
233 | |
234 | /* |
235 | * pre-allocate the buffer and create a proc file for the substream |
236 | */ |
237 | static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream, |
238 | size_t size, size_t max) |
239 | { |
240 | |
241 | if (size > 0 && preallocate_dma && substream->number < maximum_substreams) |
242 | preallocate_pcm_pages(substream, size); |
243 | |
244 | if (substream->dma_buffer.bytes > 0) |
245 | substream->buffer_bytes_max = substream->dma_buffer.bytes; |
246 | substream->dma_max = max; |
247 | preallocate_info_init(substream); |
248 | return 0; |
249 | } |
250 | |
251 | |
252 | /** |
253 | * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type |
254 | * @substream: the pcm substream instance |
255 | * @type: DMA type (SNDRV_DMA_TYPE_*) |
256 | * @data: DMA type dependant data |
257 | * @size: the requested pre-allocation size in bytes |
258 | * @max: the max. allowed pre-allocation size |
259 | * |
260 | * Do pre-allocation for the given DMA buffer type. |
261 | * |
262 | * When substream->dma_buf_id is set, the function tries to look for |
263 | * the reserved buffer, and the buffer is not freed but reserved at |
264 | * destruction time. The dma_buf_id must be unique for all systems |
265 | * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id(). |
266 | * |
267 | * Returns zero if successful, or a negative error code on failure. |
268 | */ |
269 | int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream, |
270 | int type, struct device *data, |
271 | size_t size, size_t max) |
272 | { |
273 | substream->dma_buffer.dev.type = type; |
274 | substream->dma_buffer.dev.dev = data; |
275 | return snd_pcm_lib_preallocate_pages1(substream, size, max); |
276 | } |
277 | |
278 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages); |
279 | |
280 | /** |
281 | * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams) |
282 | * @pcm: the pcm instance |
283 | * @type: DMA type (SNDRV_DMA_TYPE_*) |
284 | * @data: DMA type dependant data |
285 | * @size: the requested pre-allocation size in bytes |
286 | * @max: the max. allowed pre-allocation size |
287 | * |
288 | * Do pre-allocation to all substreams of the given pcm for the |
289 | * specified DMA type. |
290 | * |
291 | * Returns zero if successful, or a negative error code on failure. |
292 | */ |
293 | int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm, |
294 | int type, void *data, |
295 | size_t size, size_t max) |
296 | { |
297 | struct snd_pcm_substream *substream; |
298 | int stream, err; |
299 | |
300 | for (stream = 0; stream < 2; stream++) |
301 | for (substream = pcm->streams[stream].substream; substream; substream = substream->next) |
302 | if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0) |
303 | return err; |
304 | return 0; |
305 | } |
306 | |
307 | EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all); |
308 | |
309 | #ifdef CONFIG_SND_DMA_SGBUF |
310 | /** |
311 | * snd_pcm_sgbuf_ops_page - get the page struct at the given offset |
312 | * @substream: the pcm substream instance |
313 | * @offset: the buffer offset |
314 | * |
315 | * Returns the page struct at the given buffer offset. |
316 | * Used as the page callback of PCM ops. |
317 | */ |
318 | struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset) |
319 | { |
320 | struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream); |
321 | |
322 | unsigned int idx = offset >> PAGE_SHIFT; |
323 | if (idx >= (unsigned int)sgbuf->pages) |
324 | return NULL; |
325 | return sgbuf->page_table[idx]; |
326 | } |
327 | |
328 | EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page); |
329 | |
330 | /* |
331 | * compute the max chunk size with continuous pages on sg-buffer |
332 | */ |
333 | unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream, |
334 | unsigned int ofs, unsigned int size) |
335 | { |
336 | struct snd_sg_buf *sg = snd_pcm_substream_sgbuf(substream); |
337 | unsigned int start, end, pg; |
338 | |
339 | start = ofs >> PAGE_SHIFT; |
340 | end = (ofs + size - 1) >> PAGE_SHIFT; |
341 | /* check page continuity */ |
342 | pg = sg->table[start].addr >> PAGE_SHIFT; |
343 | for (;;) { |
344 | start++; |
345 | if (start > end) |
346 | break; |
347 | pg++; |
348 | if ((sg->table[start].addr >> PAGE_SHIFT) != pg) |
349 | return (start << PAGE_SHIFT) - ofs; |
350 | } |
351 | /* ok, all on continuous pages */ |
352 | return size; |
353 | } |
354 | EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size); |
355 | #endif /* CONFIG_SND_DMA_SGBUF */ |
356 | |
357 | /** |
358 | * snd_pcm_lib_malloc_pages - allocate the DMA buffer |
359 | * @substream: the substream to allocate the DMA buffer to |
360 | * @size: the requested buffer size in bytes |
361 | * |
362 | * Allocates the DMA buffer on the BUS type given earlier to |
363 | * snd_pcm_lib_preallocate_xxx_pages(). |
364 | * |
365 | * Returns 1 if the buffer is changed, 0 if not changed, or a negative |
366 | * code on failure. |
367 | */ |
368 | int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size) |
369 | { |
370 | struct snd_pcm_runtime *runtime; |
371 | struct snd_dma_buffer *dmab = NULL; |
372 | |
373 | if (PCM_RUNTIME_CHECK(substream)) |
374 | return -EINVAL; |
375 | if (snd_BUG_ON(substream->dma_buffer.dev.type == |
376 | SNDRV_DMA_TYPE_UNKNOWN)) |
377 | return -EINVAL; |
378 | runtime = substream->runtime; |
379 | |
380 | if (runtime->dma_buffer_p) { |
381 | /* perphaps, we might free the large DMA memory region |
382 | to save some space here, but the actual solution |
383 | costs us less time */ |
384 | if (runtime->dma_buffer_p->bytes >= size) { |
385 | runtime->dma_bytes = size; |
386 | return 0; /* ok, do not change */ |
387 | } |
388 | snd_pcm_lib_free_pages(substream); |
389 | } |
390 | if (substream->dma_buffer.area != NULL && |
391 | substream->dma_buffer.bytes >= size) { |
392 | dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ |
393 | } else { |
394 | dmab = kzalloc(sizeof(*dmab), GFP_KERNEL); |
395 | if (! dmab) |
396 | return -ENOMEM; |
397 | dmab->dev = substream->dma_buffer.dev; |
398 | if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, |
399 | substream->dma_buffer.dev.dev, |
400 | size, dmab) < 0) { |
401 | kfree(dmab); |
402 | return -ENOMEM; |
403 | } |
404 | } |
405 | snd_pcm_set_runtime_buffer(substream, dmab); |
406 | runtime->dma_bytes = size; |
407 | return 1; /* area was changed */ |
408 | } |
409 | |
410 | EXPORT_SYMBOL(snd_pcm_lib_malloc_pages); |
411 | |
412 | /** |
413 | * snd_pcm_lib_free_pages - release the allocated DMA buffer. |
414 | * @substream: the substream to release the DMA buffer |
415 | * |
416 | * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). |
417 | * |
418 | * Returns zero if successful, or a negative error code on failure. |
419 | */ |
420 | int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream) |
421 | { |
422 | struct snd_pcm_runtime *runtime; |
423 | |
424 | if (PCM_RUNTIME_CHECK(substream)) |
425 | return -EINVAL; |
426 | runtime = substream->runtime; |
427 | if (runtime->dma_area == NULL) |
428 | return 0; |
429 | if (runtime->dma_buffer_p != &substream->dma_buffer) { |
430 | /* it's a newly allocated buffer. release it now. */ |
431 | snd_dma_free_pages(runtime->dma_buffer_p); |
432 | kfree(runtime->dma_buffer_p); |
433 | } |
434 | snd_pcm_set_runtime_buffer(substream, NULL); |
435 | return 0; |
436 | } |
437 | |
438 | EXPORT_SYMBOL(snd_pcm_lib_free_pages); |
439 | |
440 | int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream, |
441 | size_t size, gfp_t gfp_flags) |
442 | { |
443 | struct snd_pcm_runtime *runtime; |
444 | |
445 | if (PCM_RUNTIME_CHECK(substream)) |
446 | return -EINVAL; |
447 | runtime = substream->runtime; |
448 | if (runtime->dma_area) { |
449 | if (runtime->dma_bytes >= size) |
450 | return 0; /* already large enough */ |
451 | vfree(runtime->dma_area); |
452 | } |
453 | runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
454 | if (!runtime->dma_area) |
455 | return -ENOMEM; |
456 | runtime->dma_bytes = size; |
457 | return 1; |
458 | } |
459 | EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer); |
460 | |
461 | /** |
462 | * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer |
463 | * @substream: the substream with a buffer allocated by |
464 | * snd_pcm_lib_alloc_vmalloc_buffer() |
465 | */ |
466 | int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream) |
467 | { |
468 | struct snd_pcm_runtime *runtime; |
469 | |
470 | if (PCM_RUNTIME_CHECK(substream)) |
471 | return -EINVAL; |
472 | runtime = substream->runtime; |
473 | vfree(runtime->dma_area); |
474 | runtime->dma_area = NULL; |
475 | return 0; |
476 | } |
477 | EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer); |
478 | |
479 | /** |
480 | * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct |
481 | * @substream: the substream with a buffer allocated by |
482 | * snd_pcm_lib_alloc_vmalloc_buffer() |
483 | * @offset: offset in the buffer |
484 | * |
485 | * This function is to be used as the page callback in the PCM ops. |
486 | */ |
487 | struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream, |
488 | unsigned long offset) |
489 | { |
490 | return vmalloc_to_page(substream->runtime->dma_area + offset); |
491 | } |
492 | EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page); |
493 |
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