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