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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/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 int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
35 size_t size, struct snd_dma_buffer *dmab)
36{
37 int err;
38
39 if (max_alloc_per_card &&
40 card->total_pcm_alloc_bytes + size > max_alloc_per_card)
41 return -ENOMEM;
42
43 err = snd_dma_alloc_pages(type, dev, size, dmab);
44 if (!err) {
45 mutex_lock(&card->memory_mutex);
46 card->total_pcm_alloc_bytes += dmab->bytes;
47 mutex_unlock(&card->memory_mutex);
48 }
49 return err;
50}
51
52static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
53{
54 if (!dmab->area)
55 return;
56 mutex_lock(&card->memory_mutex);
57 WARN_ON(card->total_pcm_alloc_bytes < dmab->bytes);
58 card->total_pcm_alloc_bytes -= dmab->bytes;
59 mutex_unlock(&card->memory_mutex);
60 snd_dma_free_pages(dmab);
61 dmab->area = NULL;
62}
63
64/*
65 * try to allocate as the large pages as possible.
66 * stores the resultant memory size in *res_size.
67 *
68 * the minimum size is snd_minimum_buffer. it should be power of 2.
69 */
70static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
71{
72 struct snd_dma_buffer *dmab = &substream->dma_buffer;
73 struct snd_card *card = substream->pcm->card;
74 size_t orig_size = size;
75 int err;
76
77 do {
78 err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
79 size, dmab);
80 if (err != -ENOMEM)
81 return err;
82 size >>= 1;
83 } while (size >= snd_minimum_buffer);
84 dmab->bytes = 0; /* tell error */
85 pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
86 substream->pcm->card->number, substream->pcm->device,
87 substream->stream ? 'c' : 'p', substream->number,
88 substream->pcm->name, orig_size);
89 return 0;
90}
91
92/*
93 * release the preallocated buffer if not yet done.
94 */
95static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
96{
97 do_free_pages(substream->pcm->card, &substream->dma_buffer);
98}
99
100/**
101 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
102 * @substream: the pcm substream instance
103 *
104 * Releases the pre-allocated buffer of the given substream.
105 */
106void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
107{
108 snd_pcm_lib_preallocate_dma_free(substream);
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 */
117void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
118{
119 struct snd_pcm_substream *substream;
120 int stream;
121
122 for (stream = 0; stream < 2; stream++)
123 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
124 snd_pcm_lib_preallocate_free(substream);
125}
126EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
127
128#ifdef CONFIG_SND_VERBOSE_PROCFS
129/*
130 * read callback for prealloc proc file
131 *
132 * prints the current allocated size in kB.
133 */
134static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
135 struct snd_info_buffer *buffer)
136{
137 struct snd_pcm_substream *substream = entry->private_data;
138 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
139}
140
141/*
142 * read callback for prealloc_max proc file
143 *
144 * prints the maximum allowed size in kB.
145 */
146static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
147 struct snd_info_buffer *buffer)
148{
149 struct snd_pcm_substream *substream = entry->private_data;
150 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
151}
152
153/*
154 * write callback for prealloc proc file
155 *
156 * accepts the preallocation size in kB.
157 */
158static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
159 struct snd_info_buffer *buffer)
160{
161 struct snd_pcm_substream *substream = entry->private_data;
162 struct snd_card *card = substream->pcm->card;
163 char line[64], str[64];
164 size_t size;
165 struct snd_dma_buffer new_dmab;
166
167 if (substream->runtime) {
168 buffer->error = -EBUSY;
169 return;
170 }
171 if (!snd_info_get_line(buffer, line, sizeof(line))) {
172 snd_info_get_str(str, line, sizeof(str));
173 size = simple_strtoul(str, NULL, 10) * 1024;
174 if ((size != 0 && size < 8192) || size > substream->dma_max) {
175 buffer->error = -EINVAL;
176 return;
177 }
178 if (substream->dma_buffer.bytes == size)
179 return;
180 memset(&new_dmab, 0, sizeof(new_dmab));
181 new_dmab.dev = substream->dma_buffer.dev;
182 if (size > 0) {
183 if (do_alloc_pages(card,
184 substream->dma_buffer.dev.type,
185 substream->dma_buffer.dev.dev,
186 size, &new_dmab) < 0) {
187 buffer->error = -ENOMEM;
188 return;
189 }
190 substream->buffer_bytes_max = size;
191 } else {
192 substream->buffer_bytes_max = UINT_MAX;
193 }
194 if (substream->dma_buffer.area)
195 do_free_pages(card, &substream->dma_buffer);
196 substream->dma_buffer = new_dmab;
197 } else {
198 buffer->error = -EINVAL;
199 }
200}
201
202static inline void preallocate_info_init(struct snd_pcm_substream *substream)
203{
204 struct snd_info_entry *entry;
205
206 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
207 substream->proc_root);
208 if (entry) {
209 snd_info_set_text_ops(entry, substream,
210 snd_pcm_lib_preallocate_proc_read);
211 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
212 entry->mode |= 0200;
213 }
214 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
215 substream->proc_root);
216 if (entry)
217 snd_info_set_text_ops(entry, substream,
218 snd_pcm_lib_preallocate_max_proc_read);
219}
220
221#else /* !CONFIG_SND_VERBOSE_PROCFS */
222#define preallocate_info_init(s)
223#endif /* CONFIG_SND_VERBOSE_PROCFS */
224
225/*
226 * pre-allocate the buffer and create a proc file for the substream
227 */
228static void preallocate_pages(struct snd_pcm_substream *substream,
229 int type, struct device *data,
230 size_t size, size_t max, bool managed)
231{
232 if (snd_BUG_ON(substream->dma_buffer.dev.type))
233 return;
234
235 substream->dma_buffer.dev.type = type;
236 substream->dma_buffer.dev.dev = data;
237
238 if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
239 preallocate_pcm_pages(substream, size);
240
241 if (substream->dma_buffer.bytes > 0)
242 substream->buffer_bytes_max = substream->dma_buffer.bytes;
243 substream->dma_max = max;
244 if (max > 0)
245 preallocate_info_init(substream);
246 if (managed)
247 substream->managed_buffer_alloc = 1;
248}
249
250static void preallocate_pages_for_all(struct snd_pcm *pcm, int type,
251 void *data, size_t size, size_t max,
252 bool managed)
253{
254 struct snd_pcm_substream *substream;
255 int stream;
256
257 for (stream = 0; stream < 2; stream++)
258 for (substream = pcm->streams[stream].substream; substream;
259 substream = substream->next)
260 preallocate_pages(substream, type, data, size, max,
261 managed);
262}
263
264/**
265 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
266 * @substream: the pcm substream instance
267 * @type: DMA type (SNDRV_DMA_TYPE_*)
268 * @data: DMA type dependent data
269 * @size: the requested pre-allocation size in bytes
270 * @max: the max. allowed pre-allocation size
271 *
272 * Do pre-allocation for the given DMA buffer type.
273 */
274void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
275 int type, struct device *data,
276 size_t size, size_t max)
277{
278 preallocate_pages(substream, type, data, size, max, false);
279}
280EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
281
282/**
283 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
284 * @pcm: the pcm instance
285 * @type: DMA type (SNDRV_DMA_TYPE_*)
286 * @data: DMA type dependent data
287 * @size: the requested pre-allocation size in bytes
288 * @max: the max. allowed pre-allocation size
289 *
290 * Do pre-allocation to all substreams of the given pcm for the
291 * specified DMA type.
292 */
293void 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 preallocate_pages_for_all(pcm, type, data, size, max, false);
298}
299EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
300
301/**
302 * snd_pcm_set_managed_buffer - set up buffer management for a substream
303 * @substream: the pcm substream instance
304 * @type: DMA type (SNDRV_DMA_TYPE_*)
305 * @data: DMA type dependent data
306 * @size: the requested pre-allocation size in bytes
307 * @max: the max. allowed pre-allocation size
308 *
309 * Do pre-allocation for the given DMA buffer type, and set the managed
310 * buffer allocation mode to the given substream.
311 * In this mode, PCM core will allocate a buffer automatically before PCM
312 * hw_params ops call, and release the buffer after PCM hw_free ops call
313 * as well, so that the driver doesn't need to invoke the allocation and
314 * the release explicitly in its callback.
315 * When a buffer is actually allocated before the PCM hw_params call, it
316 * turns on the runtime buffer_changed flag for drivers changing their h/w
317 * parameters accordingly.
318 */
319void snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
320 struct device *data, size_t size, size_t max)
321{
322 preallocate_pages(substream, type, data, size, max, true);
323}
324EXPORT_SYMBOL(snd_pcm_set_managed_buffer);
325
326/**
327 * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
328 * for all substreams
329 * @pcm: the pcm instance
330 * @type: DMA type (SNDRV_DMA_TYPE_*)
331 * @data: DMA type dependent data
332 * @size: the requested pre-allocation size in bytes
333 * @max: the max. allowed pre-allocation size
334 *
335 * Do pre-allocation to all substreams of the given pcm for the specified DMA
336 * type and size, and set the managed_buffer_alloc flag to each substream.
337 */
338void snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
339 struct device *data,
340 size_t size, size_t max)
341{
342 preallocate_pages_for_all(pcm, type, data, size, max, true);
343}
344EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);
345
346#ifdef CONFIG_SND_DMA_SGBUF
347/*
348 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
349 * @substream: the pcm substream instance
350 * @offset: the buffer offset
351 *
352 * Used as the page callback of PCM ops.
353 *
354 * Return: The page struct at the given buffer offset. %NULL on failure.
355 */
356struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
357{
358 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
359
360 unsigned int idx = offset >> PAGE_SHIFT;
361 if (idx >= (unsigned int)sgbuf->pages)
362 return NULL;
363 return sgbuf->page_table[idx];
364}
365#endif /* CONFIG_SND_DMA_SGBUF */
366
367/**
368 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
369 * @substream: the substream to allocate the DMA buffer to
370 * @size: the requested buffer size in bytes
371 *
372 * Allocates the DMA buffer on the BUS type given earlier to
373 * snd_pcm_lib_preallocate_xxx_pages().
374 *
375 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
376 * code on failure.
377 */
378int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
379{
380 struct snd_card *card = substream->pcm->card;
381 struct snd_pcm_runtime *runtime;
382 struct snd_dma_buffer *dmab = NULL;
383
384 if (PCM_RUNTIME_CHECK(substream))
385 return -EINVAL;
386 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
387 SNDRV_DMA_TYPE_UNKNOWN))
388 return -EINVAL;
389 runtime = substream->runtime;
390
391 if (runtime->dma_buffer_p) {
392 /* perphaps, we might free the large DMA memory region
393 to save some space here, but the actual solution
394 costs us less time */
395 if (runtime->dma_buffer_p->bytes >= size) {
396 runtime->dma_bytes = size;
397 return 0; /* ok, do not change */
398 }
399 snd_pcm_lib_free_pages(substream);
400 }
401 if (substream->dma_buffer.area != NULL &&
402 substream->dma_buffer.bytes >= size) {
403 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
404 } else {
405 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
406 if (! dmab)
407 return -ENOMEM;
408 dmab->dev = substream->dma_buffer.dev;
409 if (do_alloc_pages(card,
410 substream->dma_buffer.dev.type,
411 substream->dma_buffer.dev.dev,
412 size, dmab) < 0) {
413 kfree(dmab);
414 return -ENOMEM;
415 }
416 }
417 snd_pcm_set_runtime_buffer(substream, dmab);
418 runtime->dma_bytes = size;
419 return 1; /* area was changed */
420}
421EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
422
423/**
424 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
425 * @substream: the substream to release the DMA buffer
426 *
427 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
428 *
429 * Return: Zero if successful, or a negative error code on failure.
430 */
431int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
432{
433 struct snd_card *card = substream->pcm->card;
434 struct snd_pcm_runtime *runtime;
435
436 if (PCM_RUNTIME_CHECK(substream))
437 return -EINVAL;
438 runtime = substream->runtime;
439 if (runtime->dma_area == NULL)
440 return 0;
441 if (runtime->dma_buffer_p != &substream->dma_buffer) {
442 /* it's a newly allocated buffer. release it now. */
443 do_free_pages(card, runtime->dma_buffer_p);
444 kfree(runtime->dma_buffer_p);
445 }
446 snd_pcm_set_runtime_buffer(substream, NULL);
447 return 0;
448}
449EXPORT_SYMBOL(snd_pcm_lib_free_pages);
450
451int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
452 size_t size, gfp_t gfp_flags)
453{
454 struct snd_pcm_runtime *runtime;
455
456 if (PCM_RUNTIME_CHECK(substream))
457 return -EINVAL;
458 runtime = substream->runtime;
459 if (runtime->dma_area) {
460 if (runtime->dma_bytes >= size)
461 return 0; /* already large enough */
462 vfree(runtime->dma_area);
463 }
464 runtime->dma_area = __vmalloc(size, gfp_flags);
465 if (!runtime->dma_area)
466 return -ENOMEM;
467 runtime->dma_bytes = size;
468 return 1;
469}
470EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
471
472/**
473 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
474 * @substream: the substream with a buffer allocated by
475 * snd_pcm_lib_alloc_vmalloc_buffer()
476 *
477 * Return: Zero if successful, or a negative error code on failure.
478 */
479int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
480{
481 struct snd_pcm_runtime *runtime;
482
483 if (PCM_RUNTIME_CHECK(substream))
484 return -EINVAL;
485 runtime = substream->runtime;
486 vfree(runtime->dma_area);
487 runtime->dma_area = NULL;
488 return 0;
489}
490EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
491
492/**
493 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
494 * @substream: the substream with a buffer allocated by
495 * snd_pcm_lib_alloc_vmalloc_buffer()
496 * @offset: offset in the buffer
497 *
498 * This function is to be used as the page callback in the PCM ops.
499 *
500 * Return: The page struct, or %NULL on failure.
501 */
502struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
503 unsigned long offset)
504{
505 return vmalloc_to_page(substream->runtime->dma_area + offset);
506}
507EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);
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);