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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Digital Audio (PCM) abstract layer
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/io.h>
8#include <linux/time.h>
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/moduleparam.h>
12#include <linux/export.h>
13#include <sound/core.h>
14#include <sound/pcm.h>
15#include <sound/info.h>
16#include <sound/initval.h>
17#include "pcm_local.h"
18
19static int preallocate_dma = 1;
20module_param(preallocate_dma, int, 0444);
21MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
22
23static int maximum_substreams = 4;
24module_param(maximum_substreams, int, 0444);
25MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
26
27static const size_t snd_minimum_buffer = 16384;
28
29static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
30module_param(max_alloc_per_card, ulong, 0644);
31MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
32
33static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
34{
35 card->total_pcm_alloc_bytes += bytes;
36}
37
38static void update_allocated_size(struct snd_card *card, ssize_t bytes)
39{
40 guard(mutex)(&card->memory_mutex);
41 __update_allocated_size(card, bytes);
42}
43
44static void decrease_allocated_size(struct snd_card *card, size_t bytes)
45{
46 guard(mutex)(&card->memory_mutex);
47 WARN_ON(card->total_pcm_alloc_bytes < bytes);
48 __update_allocated_size(card, -(ssize_t)bytes);
49}
50
51static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
52 int str, size_t size, struct snd_dma_buffer *dmab)
53{
54 enum dma_data_direction dir;
55 int err;
56
57 /* check and reserve the requested size */
58 scoped_guard(mutex, &card->memory_mutex) {
59 if (max_alloc_per_card &&
60 card->total_pcm_alloc_bytes + size > max_alloc_per_card)
61 return -ENOMEM;
62 __update_allocated_size(card, size);
63 }
64
65 if (str == SNDRV_PCM_STREAM_PLAYBACK)
66 dir = DMA_TO_DEVICE;
67 else
68 dir = DMA_FROM_DEVICE;
69 err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
70 if (!err) {
71 /* the actual allocation size might be bigger than requested,
72 * and we need to correct the account
73 */
74 if (dmab->bytes != size)
75 update_allocated_size(card, dmab->bytes - size);
76 } else {
77 /* take back on allocation failure */
78 decrease_allocated_size(card, size);
79 }
80 return err;
81}
82
83static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
84{
85 if (!dmab->area)
86 return;
87 decrease_allocated_size(card, dmab->bytes);
88 snd_dma_free_pages(dmab);
89 dmab->area = NULL;
90}
91
92/*
93 * try to allocate as the large pages as possible.
94 * stores the resultant memory size in *res_size.
95 *
96 * the minimum size is snd_minimum_buffer. it should be power of 2.
97 */
98static int preallocate_pcm_pages(struct snd_pcm_substream *substream,
99 size_t size, bool no_fallback)
100{
101 struct snd_dma_buffer *dmab = &substream->dma_buffer;
102 struct snd_card *card = substream->pcm->card;
103 size_t orig_size = size;
104 int err;
105
106 do {
107 err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
108 substream->stream, size, dmab);
109 if (err != -ENOMEM)
110 return err;
111 if (no_fallback)
112 break;
113 size >>= 1;
114 } while (size >= snd_minimum_buffer);
115 dmab->bytes = 0; /* tell error */
116 pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
117 substream->pcm->card->number, substream->pcm->device,
118 substream->stream ? 'c' : 'p', substream->number,
119 substream->pcm->name, orig_size);
120 return -ENOMEM;
121}
122
123/**
124 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
125 * @substream: the pcm substream instance
126 *
127 * Releases the pre-allocated buffer of the given substream.
128 */
129void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
130{
131 do_free_pages(substream->pcm->card, &substream->dma_buffer);
132}
133
134/**
135 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
136 * @pcm: the pcm instance
137 *
138 * Releases all the pre-allocated buffers on the given pcm.
139 */
140void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
141{
142 struct snd_pcm_substream *substream;
143 int stream;
144
145 for_each_pcm_substream(pcm, stream, substream)
146 snd_pcm_lib_preallocate_free(substream);
147}
148EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
149
150#ifdef CONFIG_SND_VERBOSE_PROCFS
151/*
152 * read callback for prealloc proc file
153 *
154 * prints the current allocated size in kB.
155 */
156static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
157 struct snd_info_buffer *buffer)
158{
159 struct snd_pcm_substream *substream = entry->private_data;
160 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
161}
162
163/*
164 * read callback for prealloc_max proc file
165 *
166 * prints the maximum allowed size in kB.
167 */
168static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
169 struct snd_info_buffer *buffer)
170{
171 struct snd_pcm_substream *substream = entry->private_data;
172 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
173}
174
175/*
176 * write callback for prealloc proc file
177 *
178 * accepts the preallocation size in kB.
179 */
180static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
181 struct snd_info_buffer *buffer)
182{
183 struct snd_pcm_substream *substream = entry->private_data;
184 struct snd_card *card = substream->pcm->card;
185 char line[64], str[64];
186 unsigned long size;
187 struct snd_dma_buffer new_dmab;
188
189 guard(mutex)(&substream->pcm->open_mutex);
190 if (substream->runtime) {
191 buffer->error = -EBUSY;
192 return;
193 }
194 if (!snd_info_get_line(buffer, line, sizeof(line))) {
195 snd_info_get_str(str, line, sizeof(str));
196 buffer->error = kstrtoul(str, 10, &size);
197 if (buffer->error != 0)
198 return;
199 size *= 1024;
200 if ((size != 0 && size < 8192) || size > substream->dma_max) {
201 buffer->error = -EINVAL;
202 return;
203 }
204 if (substream->dma_buffer.bytes == size)
205 return;
206 memset(&new_dmab, 0, sizeof(new_dmab));
207 new_dmab.dev = substream->dma_buffer.dev;
208 if (size > 0) {
209 if (do_alloc_pages(card,
210 substream->dma_buffer.dev.type,
211 substream->dma_buffer.dev.dev,
212 substream->stream,
213 size, &new_dmab) < 0) {
214 buffer->error = -ENOMEM;
215 pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %lu\n",
216 substream->pcm->card->number, substream->pcm->device,
217 substream->stream ? 'c' : 'p', substream->number,
218 substream->pcm->name, size);
219 return;
220 }
221 substream->buffer_bytes_max = size;
222 } else {
223 substream->buffer_bytes_max = UINT_MAX;
224 }
225 if (substream->dma_buffer.area)
226 do_free_pages(card, &substream->dma_buffer);
227 substream->dma_buffer = new_dmab;
228 } else {
229 buffer->error = -EINVAL;
230 }
231}
232
233static inline void preallocate_info_init(struct snd_pcm_substream *substream)
234{
235 struct snd_info_entry *entry;
236
237 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
238 substream->proc_root);
239 if (entry) {
240 snd_info_set_text_ops(entry, substream,
241 snd_pcm_lib_preallocate_proc_read);
242 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
243 entry->mode |= 0200;
244 }
245 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
246 substream->proc_root);
247 if (entry)
248 snd_info_set_text_ops(entry, substream,
249 snd_pcm_lib_preallocate_max_proc_read);
250}
251
252#else /* !CONFIG_SND_VERBOSE_PROCFS */
253static inline void preallocate_info_init(struct snd_pcm_substream *substream)
254{
255}
256#endif /* CONFIG_SND_VERBOSE_PROCFS */
257
258/*
259 * pre-allocate the buffer and create a proc file for the substream
260 */
261static int preallocate_pages(struct snd_pcm_substream *substream,
262 int type, struct device *data,
263 size_t size, size_t max, bool managed)
264{
265 int err;
266
267 if (snd_BUG_ON(substream->dma_buffer.dev.type))
268 return -EINVAL;
269
270 substream->dma_buffer.dev.type = type;
271 substream->dma_buffer.dev.dev = data;
272
273 if (size > 0) {
274 if (!max) {
275 /* no fallback, only also inform -ENOMEM */
276 err = preallocate_pcm_pages(substream, size, true);
277 if (err < 0)
278 return err;
279 } else if (preallocate_dma &&
280 substream->number < maximum_substreams) {
281 err = preallocate_pcm_pages(substream, size, false);
282 if (err < 0 && err != -ENOMEM)
283 return err;
284 }
285 }
286
287 if (substream->dma_buffer.bytes > 0)
288 substream->buffer_bytes_max = substream->dma_buffer.bytes;
289 substream->dma_max = max;
290 if (max > 0)
291 preallocate_info_init(substream);
292 if (managed)
293 substream->managed_buffer_alloc = 1;
294 return 0;
295}
296
297static int preallocate_pages_for_all(struct snd_pcm *pcm, int type,
298 void *data, size_t size, size_t max,
299 bool managed)
300{
301 struct snd_pcm_substream *substream;
302 int stream, err;
303
304 for_each_pcm_substream(pcm, stream, substream) {
305 err = preallocate_pages(substream, type, data, size, max, managed);
306 if (err < 0)
307 return err;
308 }
309 return 0;
310}
311
312/**
313 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
314 * @substream: the pcm substream instance
315 * @type: DMA type (SNDRV_DMA_TYPE_*)
316 * @data: DMA type dependent data
317 * @size: the requested pre-allocation size in bytes
318 * @max: the max. allowed pre-allocation size
319 *
320 * Do pre-allocation for the given DMA buffer type.
321 */
322void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
323 int type, struct device *data,
324 size_t size, size_t max)
325{
326 preallocate_pages(substream, type, data, size, max, false);
327}
328EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
329
330/**
331 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
332 * @pcm: the pcm instance
333 * @type: DMA type (SNDRV_DMA_TYPE_*)
334 * @data: DMA type dependent data
335 * @size: the requested pre-allocation size in bytes
336 * @max: the max. allowed pre-allocation size
337 *
338 * Do pre-allocation to all substreams of the given pcm for the
339 * specified DMA type.
340 */
341void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
342 int type, void *data,
343 size_t size, size_t max)
344{
345 preallocate_pages_for_all(pcm, type, data, size, max, false);
346}
347EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
348
349/**
350 * snd_pcm_set_managed_buffer - set up buffer management for a substream
351 * @substream: the pcm substream instance
352 * @type: DMA type (SNDRV_DMA_TYPE_*)
353 * @data: DMA type dependent data
354 * @size: the requested pre-allocation size in bytes
355 * @max: the max. allowed pre-allocation size
356 *
357 * Do pre-allocation for the given DMA buffer type, and set the managed
358 * buffer allocation mode to the given substream.
359 * In this mode, PCM core will allocate a buffer automatically before PCM
360 * hw_params ops call, and release the buffer after PCM hw_free ops call
361 * as well, so that the driver doesn't need to invoke the allocation and
362 * the release explicitly in its callback.
363 * When a buffer is actually allocated before the PCM hw_params call, it
364 * turns on the runtime buffer_changed flag for drivers changing their h/w
365 * parameters accordingly.
366 *
367 * When @size is non-zero and @max is zero, this tries to allocate for only
368 * the exact buffer size without fallback, and may return -ENOMEM.
369 * Otherwise, the function tries to allocate smaller chunks if the allocation
370 * fails. This is the behavior of snd_pcm_set_fixed_buffer().
371 *
372 * When both @size and @max are zero, the function only sets up the buffer
373 * for later dynamic allocations. It's used typically for buffers with
374 * SNDRV_DMA_TYPE_VMALLOC type.
375 *
376 * Upon successful buffer allocation and setup, the function returns 0.
377 *
378 * Return: zero if successful, or a negative error code
379 */
380int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
381 struct device *data, size_t size, size_t max)
382{
383 return preallocate_pages(substream, type, data, size, max, true);
384}
385EXPORT_SYMBOL(snd_pcm_set_managed_buffer);
386
387/**
388 * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
389 * for all substreams
390 * @pcm: the pcm instance
391 * @type: DMA type (SNDRV_DMA_TYPE_*)
392 * @data: DMA type dependent data
393 * @size: the requested pre-allocation size in bytes
394 * @max: the max. allowed pre-allocation size
395 *
396 * Do pre-allocation to all substreams of the given pcm for the specified DMA
397 * type and size, and set the managed_buffer_alloc flag to each substream.
398 *
399 * Return: zero if successful, or a negative error code
400 */
401int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
402 struct device *data,
403 size_t size, size_t max)
404{
405 return preallocate_pages_for_all(pcm, type, data, size, max, true);
406}
407EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);
408
409/**
410 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
411 * @substream: the substream to allocate the DMA buffer to
412 * @size: the requested buffer size in bytes
413 *
414 * Allocates the DMA buffer on the BUS type given earlier to
415 * snd_pcm_lib_preallocate_xxx_pages().
416 *
417 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
418 * code on failure.
419 */
420int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
421{
422 struct snd_card *card;
423 struct snd_pcm_runtime *runtime;
424 struct snd_dma_buffer *dmab = NULL;
425
426 if (PCM_RUNTIME_CHECK(substream))
427 return -EINVAL;
428 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
429 SNDRV_DMA_TYPE_UNKNOWN))
430 return -EINVAL;
431 runtime = substream->runtime;
432 card = substream->pcm->card;
433
434 if (runtime->dma_buffer_p) {
435 /* perphaps, we might free the large DMA memory region
436 to save some space here, but the actual solution
437 costs us less time */
438 if (runtime->dma_buffer_p->bytes >= size) {
439 runtime->dma_bytes = size;
440 return 0; /* ok, do not change */
441 }
442 snd_pcm_lib_free_pages(substream);
443 }
444 if (substream->dma_buffer.area != NULL &&
445 substream->dma_buffer.bytes >= size) {
446 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
447 } else {
448 /* dma_max=0 means the fixed size preallocation */
449 if (substream->dma_buffer.area && !substream->dma_max)
450 return -ENOMEM;
451 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
452 if (! dmab)
453 return -ENOMEM;
454 dmab->dev = substream->dma_buffer.dev;
455 if (do_alloc_pages(card,
456 substream->dma_buffer.dev.type,
457 substream->dma_buffer.dev.dev,
458 substream->stream,
459 size, dmab) < 0) {
460 kfree(dmab);
461 pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
462 substream->pcm->card->number, substream->pcm->device,
463 substream->stream ? 'c' : 'p', substream->number,
464 substream->pcm->name, size);
465 return -ENOMEM;
466 }
467 }
468 snd_pcm_set_runtime_buffer(substream, dmab);
469 runtime->dma_bytes = size;
470 return 1; /* area was changed */
471}
472EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
473
474/**
475 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
476 * @substream: the substream to release the DMA buffer
477 *
478 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
479 *
480 * Return: Zero if successful, or a negative error code on failure.
481 */
482int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
483{
484 struct snd_pcm_runtime *runtime;
485
486 if (PCM_RUNTIME_CHECK(substream))
487 return -EINVAL;
488 runtime = substream->runtime;
489 if (runtime->dma_area == NULL)
490 return 0;
491 if (runtime->dma_buffer_p != &substream->dma_buffer) {
492 struct snd_card *card = substream->pcm->card;
493
494 /* it's a newly allocated buffer. release it now. */
495 do_free_pages(card, runtime->dma_buffer_p);
496 kfree(runtime->dma_buffer_p);
497 }
498 snd_pcm_set_runtime_buffer(substream, NULL);
499 return 0;
500}
501EXPORT_SYMBOL(snd_pcm_lib_free_pages);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Digital Audio (PCM) abstract layer
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/io.h>
8#include <linux/time.h>
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/moduleparam.h>
12#include <linux/vmalloc.h>
13#include <linux/export.h>
14#include <sound/core.h>
15#include <sound/pcm.h>
16#include <sound/info.h>
17#include <sound/initval.h>
18#include "pcm_local.h"
19
20static int preallocate_dma = 1;
21module_param(preallocate_dma, int, 0444);
22MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
23
24static int maximum_substreams = 4;
25module_param(maximum_substreams, int, 0444);
26MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
27
28static const size_t snd_minimum_buffer = 16384;
29
30static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
31module_param(max_alloc_per_card, ulong, 0644);
32MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
33
34static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
35{
36 card->total_pcm_alloc_bytes += bytes;
37}
38
39static void update_allocated_size(struct snd_card *card, ssize_t bytes)
40{
41 mutex_lock(&card->memory_mutex);
42 __update_allocated_size(card, bytes);
43 mutex_unlock(&card->memory_mutex);
44}
45
46static void decrease_allocated_size(struct snd_card *card, size_t bytes)
47{
48 mutex_lock(&card->memory_mutex);
49 WARN_ON(card->total_pcm_alloc_bytes < bytes);
50 __update_allocated_size(card, -(ssize_t)bytes);
51 mutex_unlock(&card->memory_mutex);
52}
53
54static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
55 int str, size_t size, struct snd_dma_buffer *dmab)
56{
57 enum dma_data_direction dir;
58 int err;
59
60 /* check and reserve the requested size */
61 mutex_lock(&card->memory_mutex);
62 if (max_alloc_per_card &&
63 card->total_pcm_alloc_bytes + size > max_alloc_per_card) {
64 mutex_unlock(&card->memory_mutex);
65 return -ENOMEM;
66 }
67 __update_allocated_size(card, size);
68 mutex_unlock(&card->memory_mutex);
69
70 if (str == SNDRV_PCM_STREAM_PLAYBACK)
71 dir = DMA_TO_DEVICE;
72 else
73 dir = DMA_FROM_DEVICE;
74 err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
75 if (!err) {
76 /* the actual allocation size might be bigger than requested,
77 * and we need to correct the account
78 */
79 if (dmab->bytes != size)
80 update_allocated_size(card, dmab->bytes - size);
81 } else {
82 /* take back on allocation failure */
83 decrease_allocated_size(card, size);
84 }
85 return err;
86}
87
88static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
89{
90 if (!dmab->area)
91 return;
92 decrease_allocated_size(card, dmab->bytes);
93 snd_dma_free_pages(dmab);
94 dmab->area = NULL;
95}
96
97/*
98 * try to allocate as the large pages as possible.
99 * stores the resultant memory size in *res_size.
100 *
101 * the minimum size is snd_minimum_buffer. it should be power of 2.
102 */
103static int preallocate_pcm_pages(struct snd_pcm_substream *substream,
104 size_t size, bool no_fallback)
105{
106 struct snd_dma_buffer *dmab = &substream->dma_buffer;
107 struct snd_card *card = substream->pcm->card;
108 size_t orig_size = size;
109 int err;
110
111 do {
112 err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
113 substream->stream, size, dmab);
114 if (err != -ENOMEM)
115 return err;
116 if (no_fallback)
117 break;
118 size >>= 1;
119 } while (size >= snd_minimum_buffer);
120 dmab->bytes = 0; /* tell error */
121 pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
122 substream->pcm->card->number, substream->pcm->device,
123 substream->stream ? 'c' : 'p', substream->number,
124 substream->pcm->name, orig_size);
125 return -ENOMEM;
126}
127
128/**
129 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
130 * @substream: the pcm substream instance
131 *
132 * Releases the pre-allocated buffer of the given substream.
133 */
134void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
135{
136 do_free_pages(substream->pcm->card, &substream->dma_buffer);
137}
138
139/**
140 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
141 * @pcm: the pcm instance
142 *
143 * Releases all the pre-allocated buffers on the given pcm.
144 */
145void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
146{
147 struct snd_pcm_substream *substream;
148 int stream;
149
150 for_each_pcm_substream(pcm, stream, substream)
151 snd_pcm_lib_preallocate_free(substream);
152}
153EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
154
155#ifdef CONFIG_SND_VERBOSE_PROCFS
156/*
157 * read callback for prealloc proc file
158 *
159 * prints the current allocated size in kB.
160 */
161static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
162 struct snd_info_buffer *buffer)
163{
164 struct snd_pcm_substream *substream = entry->private_data;
165 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
166}
167
168/*
169 * read callback for prealloc_max proc file
170 *
171 * prints the maximum allowed size in kB.
172 */
173static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
174 struct snd_info_buffer *buffer)
175{
176 struct snd_pcm_substream *substream = entry->private_data;
177 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
178}
179
180/*
181 * write callback for prealloc proc file
182 *
183 * accepts the preallocation size in kB.
184 */
185static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
186 struct snd_info_buffer *buffer)
187{
188 struct snd_pcm_substream *substream = entry->private_data;
189 struct snd_card *card = substream->pcm->card;
190 char line[64], str[64];
191 size_t size;
192 struct snd_dma_buffer new_dmab;
193
194 mutex_lock(&substream->pcm->open_mutex);
195 if (substream->runtime) {
196 buffer->error = -EBUSY;
197 goto unlock;
198 }
199 if (!snd_info_get_line(buffer, line, sizeof(line))) {
200 snd_info_get_str(str, line, sizeof(str));
201 size = simple_strtoul(str, NULL, 10) * 1024;
202 if ((size != 0 && size < 8192) || size > substream->dma_max) {
203 buffer->error = -EINVAL;
204 goto unlock;
205 }
206 if (substream->dma_buffer.bytes == size)
207 goto unlock;
208 memset(&new_dmab, 0, sizeof(new_dmab));
209 new_dmab.dev = substream->dma_buffer.dev;
210 if (size > 0) {
211 if (do_alloc_pages(card,
212 substream->dma_buffer.dev.type,
213 substream->dma_buffer.dev.dev,
214 substream->stream,
215 size, &new_dmab) < 0) {
216 buffer->error = -ENOMEM;
217 pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
218 substream->pcm->card->number, substream->pcm->device,
219 substream->stream ? 'c' : 'p', substream->number,
220 substream->pcm->name, size);
221 goto unlock;
222 }
223 substream->buffer_bytes_max = size;
224 } else {
225 substream->buffer_bytes_max = UINT_MAX;
226 }
227 if (substream->dma_buffer.area)
228 do_free_pages(card, &substream->dma_buffer);
229 substream->dma_buffer = new_dmab;
230 } else {
231 buffer->error = -EINVAL;
232 }
233 unlock:
234 mutex_unlock(&substream->pcm->open_mutex);
235}
236
237static inline void preallocate_info_init(struct snd_pcm_substream *substream)
238{
239 struct snd_info_entry *entry;
240
241 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
242 substream->proc_root);
243 if (entry) {
244 snd_info_set_text_ops(entry, substream,
245 snd_pcm_lib_preallocate_proc_read);
246 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
247 entry->mode |= 0200;
248 }
249 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
250 substream->proc_root);
251 if (entry)
252 snd_info_set_text_ops(entry, substream,
253 snd_pcm_lib_preallocate_max_proc_read);
254}
255
256#else /* !CONFIG_SND_VERBOSE_PROCFS */
257static inline void preallocate_info_init(struct snd_pcm_substream *substream)
258{
259}
260#endif /* CONFIG_SND_VERBOSE_PROCFS */
261
262/*
263 * pre-allocate the buffer and create a proc file for the substream
264 */
265static int preallocate_pages(struct snd_pcm_substream *substream,
266 int type, struct device *data,
267 size_t size, size_t max, bool managed)
268{
269 int err;
270
271 if (snd_BUG_ON(substream->dma_buffer.dev.type))
272 return -EINVAL;
273
274 substream->dma_buffer.dev.type = type;
275 substream->dma_buffer.dev.dev = data;
276
277 if (size > 0) {
278 if (!max) {
279 /* no fallback, only also inform -ENOMEM */
280 err = preallocate_pcm_pages(substream, size, true);
281 if (err < 0)
282 return err;
283 } else if (preallocate_dma &&
284 substream->number < maximum_substreams) {
285 err = preallocate_pcm_pages(substream, size, false);
286 if (err < 0 && err != -ENOMEM)
287 return err;
288 }
289 }
290
291 if (substream->dma_buffer.bytes > 0)
292 substream->buffer_bytes_max = substream->dma_buffer.bytes;
293 substream->dma_max = max;
294 if (max > 0)
295 preallocate_info_init(substream);
296 if (managed)
297 substream->managed_buffer_alloc = 1;
298 return 0;
299}
300
301static int preallocate_pages_for_all(struct snd_pcm *pcm, int type,
302 void *data, size_t size, size_t max,
303 bool managed)
304{
305 struct snd_pcm_substream *substream;
306 int stream, err;
307
308 for_each_pcm_substream(pcm, stream, substream) {
309 err = preallocate_pages(substream, type, data, size, max, managed);
310 if (err < 0)
311 return err;
312 }
313 return 0;
314}
315
316/**
317 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
318 * @substream: the pcm substream instance
319 * @type: DMA type (SNDRV_DMA_TYPE_*)
320 * @data: DMA type dependent data
321 * @size: the requested pre-allocation size in bytes
322 * @max: the max. allowed pre-allocation size
323 *
324 * Do pre-allocation for the given DMA buffer type.
325 */
326void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
327 int type, struct device *data,
328 size_t size, size_t max)
329{
330 preallocate_pages(substream, type, data, size, max, false);
331}
332EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
333
334/**
335 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
336 * @pcm: the pcm instance
337 * @type: DMA type (SNDRV_DMA_TYPE_*)
338 * @data: DMA type dependent data
339 * @size: the requested pre-allocation size in bytes
340 * @max: the max. allowed pre-allocation size
341 *
342 * Do pre-allocation to all substreams of the given pcm for the
343 * specified DMA type.
344 */
345void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
346 int type, void *data,
347 size_t size, size_t max)
348{
349 preallocate_pages_for_all(pcm, type, data, size, max, false);
350}
351EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
352
353/**
354 * snd_pcm_set_managed_buffer - set up buffer management for a substream
355 * @substream: the pcm substream instance
356 * @type: DMA type (SNDRV_DMA_TYPE_*)
357 * @data: DMA type dependent data
358 * @size: the requested pre-allocation size in bytes
359 * @max: the max. allowed pre-allocation size
360 *
361 * Do pre-allocation for the given DMA buffer type, and set the managed
362 * buffer allocation mode to the given substream.
363 * In this mode, PCM core will allocate a buffer automatically before PCM
364 * hw_params ops call, and release the buffer after PCM hw_free ops call
365 * as well, so that the driver doesn't need to invoke the allocation and
366 * the release explicitly in its callback.
367 * When a buffer is actually allocated before the PCM hw_params call, it
368 * turns on the runtime buffer_changed flag for drivers changing their h/w
369 * parameters accordingly.
370 *
371 * When @size is non-zero and @max is zero, this tries to allocate for only
372 * the exact buffer size without fallback, and may return -ENOMEM.
373 * Otherwise, the function tries to allocate smaller chunks if the allocation
374 * fails. This is the behavior of snd_pcm_set_fixed_buffer().
375 *
376 * When both @size and @max are zero, the function only sets up the buffer
377 * for later dynamic allocations. It's used typically for buffers with
378 * SNDRV_DMA_TYPE_VMALLOC type.
379 *
380 * Upon successful buffer allocation and setup, the function returns 0.
381 *
382 * Return: zero if successful, or a negative error code
383 */
384int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
385 struct device *data, size_t size, size_t max)
386{
387 return preallocate_pages(substream, type, data, size, max, true);
388}
389EXPORT_SYMBOL(snd_pcm_set_managed_buffer);
390
391/**
392 * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
393 * for all substreams
394 * @pcm: the pcm instance
395 * @type: DMA type (SNDRV_DMA_TYPE_*)
396 * @data: DMA type dependent data
397 * @size: the requested pre-allocation size in bytes
398 * @max: the max. allowed pre-allocation size
399 *
400 * Do pre-allocation to all substreams of the given pcm for the specified DMA
401 * type and size, and set the managed_buffer_alloc flag to each substream.
402 *
403 * Return: zero if successful, or a negative error code
404 */
405int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
406 struct device *data,
407 size_t size, size_t max)
408{
409 return preallocate_pages_for_all(pcm, type, data, size, max, true);
410}
411EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);
412
413/**
414 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
415 * @substream: the substream to allocate the DMA buffer to
416 * @size: the requested buffer size in bytes
417 *
418 * Allocates the DMA buffer on the BUS type given earlier to
419 * snd_pcm_lib_preallocate_xxx_pages().
420 *
421 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
422 * code on failure.
423 */
424int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
425{
426 struct snd_card *card;
427 struct snd_pcm_runtime *runtime;
428 struct snd_dma_buffer *dmab = NULL;
429
430 if (PCM_RUNTIME_CHECK(substream))
431 return -EINVAL;
432 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
433 SNDRV_DMA_TYPE_UNKNOWN))
434 return -EINVAL;
435 runtime = substream->runtime;
436 card = substream->pcm->card;
437
438 if (runtime->dma_buffer_p) {
439 /* perphaps, we might free the large DMA memory region
440 to save some space here, but the actual solution
441 costs us less time */
442 if (runtime->dma_buffer_p->bytes >= size) {
443 runtime->dma_bytes = size;
444 return 0; /* ok, do not change */
445 }
446 snd_pcm_lib_free_pages(substream);
447 }
448 if (substream->dma_buffer.area != NULL &&
449 substream->dma_buffer.bytes >= size) {
450 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
451 } else {
452 /* dma_max=0 means the fixed size preallocation */
453 if (substream->dma_buffer.area && !substream->dma_max)
454 return -ENOMEM;
455 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
456 if (! dmab)
457 return -ENOMEM;
458 dmab->dev = substream->dma_buffer.dev;
459 if (do_alloc_pages(card,
460 substream->dma_buffer.dev.type,
461 substream->dma_buffer.dev.dev,
462 substream->stream,
463 size, dmab) < 0) {
464 kfree(dmab);
465 pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
466 substream->pcm->card->number, substream->pcm->device,
467 substream->stream ? 'c' : 'p', substream->number,
468 substream->pcm->name, size);
469 return -ENOMEM;
470 }
471 }
472 snd_pcm_set_runtime_buffer(substream, dmab);
473 runtime->dma_bytes = size;
474 return 1; /* area was changed */
475}
476EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
477
478/**
479 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
480 * @substream: the substream to release the DMA buffer
481 *
482 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
483 *
484 * Return: Zero if successful, or a negative error code on failure.
485 */
486int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
487{
488 struct snd_pcm_runtime *runtime;
489
490 if (PCM_RUNTIME_CHECK(substream))
491 return -EINVAL;
492 runtime = substream->runtime;
493 if (runtime->dma_area == NULL)
494 return 0;
495 if (runtime->dma_buffer_p != &substream->dma_buffer) {
496 struct snd_card *card = substream->pcm->card;
497
498 /* it's a newly allocated buffer. release it now. */
499 do_free_pages(card, runtime->dma_buffer_p);
500 kfree(runtime->dma_buffer_p);
501 }
502 snd_pcm_set_runtime_buffer(substream, NULL);
503 return 0;
504}
505EXPORT_SYMBOL(snd_pcm_lib_free_pages);
506
507int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
508 size_t size, gfp_t gfp_flags)
509{
510 struct snd_pcm_runtime *runtime;
511
512 if (PCM_RUNTIME_CHECK(substream))
513 return -EINVAL;
514 runtime = substream->runtime;
515 if (runtime->dma_area) {
516 if (runtime->dma_bytes >= size)
517 return 0; /* already large enough */
518 vfree(runtime->dma_area);
519 }
520 runtime->dma_area = __vmalloc(size, gfp_flags);
521 if (!runtime->dma_area)
522 return -ENOMEM;
523 runtime->dma_bytes = size;
524 return 1;
525}
526EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
527
528/**
529 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
530 * @substream: the substream with a buffer allocated by
531 * snd_pcm_lib_alloc_vmalloc_buffer()
532 *
533 * Return: Zero if successful, or a negative error code on failure.
534 */
535int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
536{
537 struct snd_pcm_runtime *runtime;
538
539 if (PCM_RUNTIME_CHECK(substream))
540 return -EINVAL;
541 runtime = substream->runtime;
542 vfree(runtime->dma_area);
543 runtime->dma_area = NULL;
544 return 0;
545}
546EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
547
548/**
549 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
550 * @substream: the substream with a buffer allocated by
551 * snd_pcm_lib_alloc_vmalloc_buffer()
552 * @offset: offset in the buffer
553 *
554 * This function is to be used as the page callback in the PCM ops.
555 *
556 * Return: The page struct, or %NULL on failure.
557 */
558struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
559 unsigned long offset)
560{
561 return vmalloc_to_page(substream->runtime->dma_area + offset);
562}
563EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);