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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
34static int preallocate_dma = 1;
35module_param(preallocate_dma, int, 0444);
36MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
37
38static int maximum_substreams = 4;
39module_param(maximum_substreams, int, 0444);
40MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
41
42static 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 */
51static 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 */
81static 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 */
100int 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 */
120int 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
131EXPORT_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 */
139static 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 */
151static 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 */
163static 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
205static 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 */
238static 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 */
270int 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
279EXPORT_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 */
294int 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
308EXPORT_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 */
319struct 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
329EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
330
331/*
332 * compute the max chunk size with continuous pages on sg-buffer
333 */
334unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
335 unsigned int ofs, unsigned int size)
336{
337 struct snd_sg_buf *sg = snd_pcm_substream_sgbuf(substream);
338 unsigned int start, end, pg;
339
340 start = ofs >> PAGE_SHIFT;
341 end = (ofs + size - 1) >> PAGE_SHIFT;
342 /* check page continuity */
343 pg = sg->table[start].addr >> PAGE_SHIFT;
344 for (;;) {
345 start++;
346 if (start > end)
347 break;
348 pg++;
349 if ((sg->table[start].addr >> PAGE_SHIFT) != pg)
350 return (start << PAGE_SHIFT) - ofs;
351 }
352 /* ok, all on continuous pages */
353 return size;
354}
355EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size);
356#endif /* CONFIG_SND_DMA_SGBUF */
357
358/**
359 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
360 * @substream: the substream to allocate the DMA buffer to
361 * @size: the requested buffer size in bytes
362 *
363 * Allocates the DMA buffer on the BUS type given earlier to
364 * snd_pcm_lib_preallocate_xxx_pages().
365 *
366 * Returns 1 if the buffer is changed, 0 if not changed, or a negative
367 * code on failure.
368 */
369int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
370{
371 struct snd_pcm_runtime *runtime;
372 struct snd_dma_buffer *dmab = NULL;
373
374 if (PCM_RUNTIME_CHECK(substream))
375 return -EINVAL;
376 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
377 SNDRV_DMA_TYPE_UNKNOWN))
378 return -EINVAL;
379 runtime = substream->runtime;
380
381 if (runtime->dma_buffer_p) {
382 /* perphaps, we might free the large DMA memory region
383 to save some space here, but the actual solution
384 costs us less time */
385 if (runtime->dma_buffer_p->bytes >= size) {
386 runtime->dma_bytes = size;
387 return 0; /* ok, do not change */
388 }
389 snd_pcm_lib_free_pages(substream);
390 }
391 if (substream->dma_buffer.area != NULL &&
392 substream->dma_buffer.bytes >= size) {
393 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
394 } else {
395 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
396 if (! dmab)
397 return -ENOMEM;
398 dmab->dev = substream->dma_buffer.dev;
399 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
400 substream->dma_buffer.dev.dev,
401 size, dmab) < 0) {
402 kfree(dmab);
403 return -ENOMEM;
404 }
405 }
406 snd_pcm_set_runtime_buffer(substream, dmab);
407 runtime->dma_bytes = size;
408 return 1; /* area was changed */
409}
410
411EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
412
413/**
414 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
415 * @substream: the substream to release the DMA buffer
416 *
417 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
418 *
419 * Returns zero if successful, or a negative error code on failure.
420 */
421int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
422{
423 struct snd_pcm_runtime *runtime;
424
425 if (PCM_RUNTIME_CHECK(substream))
426 return -EINVAL;
427 runtime = substream->runtime;
428 if (runtime->dma_area == NULL)
429 return 0;
430 if (runtime->dma_buffer_p != &substream->dma_buffer) {
431 /* it's a newly allocated buffer. release it now. */
432 snd_dma_free_pages(runtime->dma_buffer_p);
433 kfree(runtime->dma_buffer_p);
434 }
435 snd_pcm_set_runtime_buffer(substream, NULL);
436 return 0;
437}
438
439EXPORT_SYMBOL(snd_pcm_lib_free_pages);
440
441int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
442 size_t size, gfp_t gfp_flags)
443{
444 struct snd_pcm_runtime *runtime;
445
446 if (PCM_RUNTIME_CHECK(substream))
447 return -EINVAL;
448 runtime = substream->runtime;
449 if (runtime->dma_area) {
450 if (runtime->dma_bytes >= size)
451 return 0; /* already large enough */
452 vfree(runtime->dma_area);
453 }
454 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
455 if (!runtime->dma_area)
456 return -ENOMEM;
457 runtime->dma_bytes = size;
458 return 1;
459}
460EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
461
462/**
463 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
464 * @substream: the substream with a buffer allocated by
465 * snd_pcm_lib_alloc_vmalloc_buffer()
466 */
467int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
468{
469 struct snd_pcm_runtime *runtime;
470
471 if (PCM_RUNTIME_CHECK(substream))
472 return -EINVAL;
473 runtime = substream->runtime;
474 vfree(runtime->dma_area);
475 runtime->dma_area = NULL;
476 return 0;
477}
478EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
479
480/**
481 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
482 * @substream: the substream with a buffer allocated by
483 * snd_pcm_lib_alloc_vmalloc_buffer()
484 * @offset: offset in the buffer
485 *
486 * This function is to be used as the page callback in the PCM ops.
487 */
488struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
489 unsigned long offset)
490{
491 return vmalloc_to_page(substream->runtime->dma_area + offset);
492}
493EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);