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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
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
29
30/*
31 * try to allocate as the large pages as possible.
32 * stores the resultant memory size in *res_size.
33 *
34 * the minimum size is snd_minimum_buffer. it should be power of 2.
35 */
36static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
37{
38 struct snd_dma_buffer *dmab = &substream->dma_buffer;
39 size_t orig_size = size;
40 int err;
41
42 do {
43 if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
44 size, dmab)) < 0) {
45 if (err != -ENOMEM)
46 return err; /* fatal error */
47 } else
48 return 0;
49 size >>= 1;
50 } while (size >= snd_minimum_buffer);
51 dmab->bytes = 0; /* tell error */
52 pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
53 substream->pcm->card->number, substream->pcm->device,
54 substream->stream ? 'c' : 'p', substream->number,
55 substream->pcm->name, orig_size);
56 return 0;
57}
58
59/*
60 * release the preallocated buffer if not yet done.
61 */
62static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
63{
64 if (substream->dma_buffer.area == NULL)
65 return;
66 snd_dma_free_pages(&substream->dma_buffer);
67 substream->dma_buffer.area = NULL;
68}
69
70/**
71 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
72 * @substream: the pcm substream instance
73 *
74 * Releases the pre-allocated buffer of the given substream.
75 */
76void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
77{
78 snd_pcm_lib_preallocate_dma_free(substream);
79}
80
81/**
82 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
83 * @pcm: the pcm instance
84 *
85 * Releases all the pre-allocated buffers on the given pcm.
86 */
87void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
88{
89 struct snd_pcm_substream *substream;
90 int stream;
91
92 for (stream = 0; stream < 2; stream++)
93 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
94 snd_pcm_lib_preallocate_free(substream);
95}
96EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
97
98#ifdef CONFIG_SND_VERBOSE_PROCFS
99/*
100 * read callback for prealloc proc file
101 *
102 * prints the current allocated size in kB.
103 */
104static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
105 struct snd_info_buffer *buffer)
106{
107 struct snd_pcm_substream *substream = entry->private_data;
108 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
109}
110
111/*
112 * read callback for prealloc_max proc file
113 *
114 * prints the maximum allowed size in kB.
115 */
116static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
117 struct snd_info_buffer *buffer)
118{
119 struct snd_pcm_substream *substream = entry->private_data;
120 snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
121}
122
123/*
124 * write callback for prealloc proc file
125 *
126 * accepts the preallocation size in kB.
127 */
128static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
129 struct snd_info_buffer *buffer)
130{
131 struct snd_pcm_substream *substream = entry->private_data;
132 char line[64], str[64];
133 size_t size;
134 struct snd_dma_buffer new_dmab;
135
136 if (substream->runtime) {
137 buffer->error = -EBUSY;
138 return;
139 }
140 if (!snd_info_get_line(buffer, line, sizeof(line))) {
141 snd_info_get_str(str, line, sizeof(str));
142 size = simple_strtoul(str, NULL, 10) * 1024;
143 if ((size != 0 && size < 8192) || size > substream->dma_max) {
144 buffer->error = -EINVAL;
145 return;
146 }
147 if (substream->dma_buffer.bytes == size)
148 return;
149 memset(&new_dmab, 0, sizeof(new_dmab));
150 new_dmab.dev = substream->dma_buffer.dev;
151 if (size > 0) {
152 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
153 substream->dma_buffer.dev.dev,
154 size, &new_dmab) < 0) {
155 buffer->error = -ENOMEM;
156 return;
157 }
158 substream->buffer_bytes_max = size;
159 } else {
160 substream->buffer_bytes_max = UINT_MAX;
161 }
162 if (substream->dma_buffer.area)
163 snd_dma_free_pages(&substream->dma_buffer);
164 substream->dma_buffer = new_dmab;
165 } else {
166 buffer->error = -EINVAL;
167 }
168}
169
170static inline void preallocate_info_init(struct snd_pcm_substream *substream)
171{
172 struct snd_info_entry *entry;
173
174 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
175 substream->proc_root);
176 if (entry) {
177 snd_info_set_text_ops(entry, substream,
178 snd_pcm_lib_preallocate_proc_read);
179 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
180 entry->mode |= 0200;
181 }
182 entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
183 substream->proc_root);
184 if (entry)
185 snd_info_set_text_ops(entry, substream,
186 snd_pcm_lib_preallocate_max_proc_read);
187}
188
189#else /* !CONFIG_SND_VERBOSE_PROCFS */
190#define preallocate_info_init(s)
191#endif /* CONFIG_SND_VERBOSE_PROCFS */
192
193/*
194 * pre-allocate the buffer and create a proc file for the substream
195 */
196static void snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
197 size_t size, size_t max)
198{
199
200 if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
201 preallocate_pcm_pages(substream, size);
202
203 if (substream->dma_buffer.bytes > 0)
204 substream->buffer_bytes_max = substream->dma_buffer.bytes;
205 substream->dma_max = max;
206 preallocate_info_init(substream);
207}
208
209
210/**
211 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
212 * @substream: the pcm substream instance
213 * @type: DMA type (SNDRV_DMA_TYPE_*)
214 * @data: DMA type dependent data
215 * @size: the requested pre-allocation size in bytes
216 * @max: the max. allowed pre-allocation size
217 *
218 * Do pre-allocation for the given DMA buffer type.
219 */
220void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
221 int type, struct device *data,
222 size_t size, size_t max)
223{
224 substream->dma_buffer.dev.type = type;
225 substream->dma_buffer.dev.dev = data;
226 snd_pcm_lib_preallocate_pages1(substream, size, max);
227}
228EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
229
230/**
231 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
232 * @pcm: the pcm instance
233 * @type: DMA type (SNDRV_DMA_TYPE_*)
234 * @data: DMA type dependent data
235 * @size: the requested pre-allocation size in bytes
236 * @max: the max. allowed pre-allocation size
237 *
238 * Do pre-allocation to all substreams of the given pcm for the
239 * specified DMA type.
240 */
241void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
242 int type, void *data,
243 size_t size, size_t max)
244{
245 struct snd_pcm_substream *substream;
246 int stream;
247
248 for (stream = 0; stream < 2; stream++)
249 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
250 snd_pcm_lib_preallocate_pages(substream, type, data, size, max);
251}
252EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
253
254#ifdef CONFIG_SND_DMA_SGBUF
255/**
256 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
257 * @substream: the pcm substream instance
258 * @offset: the buffer offset
259 *
260 * Used as the page callback of PCM ops.
261 *
262 * Return: The page struct at the given buffer offset. %NULL on failure.
263 */
264struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
265{
266 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
267
268 unsigned int idx = offset >> PAGE_SHIFT;
269 if (idx >= (unsigned int)sgbuf->pages)
270 return NULL;
271 return sgbuf->page_table[idx];
272}
273EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
274#endif /* CONFIG_SND_DMA_SGBUF */
275
276/**
277 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
278 * @substream: the substream to allocate the DMA buffer to
279 * @size: the requested buffer size in bytes
280 *
281 * Allocates the DMA buffer on the BUS type given earlier to
282 * snd_pcm_lib_preallocate_xxx_pages().
283 *
284 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
285 * code on failure.
286 */
287int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
288{
289 struct snd_pcm_runtime *runtime;
290 struct snd_dma_buffer *dmab = NULL;
291
292 if (PCM_RUNTIME_CHECK(substream))
293 return -EINVAL;
294 if (snd_BUG_ON(substream->dma_buffer.dev.type ==
295 SNDRV_DMA_TYPE_UNKNOWN))
296 return -EINVAL;
297 runtime = substream->runtime;
298
299 if (runtime->dma_buffer_p) {
300 /* perphaps, we might free the large DMA memory region
301 to save some space here, but the actual solution
302 costs us less time */
303 if (runtime->dma_buffer_p->bytes >= size) {
304 runtime->dma_bytes = size;
305 return 0; /* ok, do not change */
306 }
307 snd_pcm_lib_free_pages(substream);
308 }
309 if (substream->dma_buffer.area != NULL &&
310 substream->dma_buffer.bytes >= size) {
311 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
312 } else {
313 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
314 if (! dmab)
315 return -ENOMEM;
316 dmab->dev = substream->dma_buffer.dev;
317 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
318 substream->dma_buffer.dev.dev,
319 size, dmab) < 0) {
320 kfree(dmab);
321 return -ENOMEM;
322 }
323 }
324 snd_pcm_set_runtime_buffer(substream, dmab);
325 runtime->dma_bytes = size;
326 return 1; /* area was changed */
327}
328EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
329
330/**
331 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
332 * @substream: the substream to release the DMA buffer
333 *
334 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
335 *
336 * Return: Zero if successful, or a negative error code on failure.
337 */
338int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
339{
340 struct snd_pcm_runtime *runtime;
341
342 if (PCM_RUNTIME_CHECK(substream))
343 return -EINVAL;
344 runtime = substream->runtime;
345 if (runtime->dma_area == NULL)
346 return 0;
347 if (runtime->dma_buffer_p != &substream->dma_buffer) {
348 /* it's a newly allocated buffer. release it now. */
349 snd_dma_free_pages(runtime->dma_buffer_p);
350 kfree(runtime->dma_buffer_p);
351 }
352 snd_pcm_set_runtime_buffer(substream, NULL);
353 return 0;
354}
355EXPORT_SYMBOL(snd_pcm_lib_free_pages);
356
357int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
358 size_t size, gfp_t gfp_flags)
359{
360 struct snd_pcm_runtime *runtime;
361
362 if (PCM_RUNTIME_CHECK(substream))
363 return -EINVAL;
364 runtime = substream->runtime;
365 if (runtime->dma_area) {
366 if (runtime->dma_bytes >= size)
367 return 0; /* already large enough */
368 vfree(runtime->dma_area);
369 }
370 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
371 if (!runtime->dma_area)
372 return -ENOMEM;
373 runtime->dma_bytes = size;
374 return 1;
375}
376EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
377
378/**
379 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
380 * @substream: the substream with a buffer allocated by
381 * snd_pcm_lib_alloc_vmalloc_buffer()
382 *
383 * Return: Zero if successful, or a negative error code on failure.
384 */
385int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
386{
387 struct snd_pcm_runtime *runtime;
388
389 if (PCM_RUNTIME_CHECK(substream))
390 return -EINVAL;
391 runtime = substream->runtime;
392 vfree(runtime->dma_area);
393 runtime->dma_area = NULL;
394 return 0;
395}
396EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
397
398/**
399 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
400 * @substream: the substream with a buffer allocated by
401 * snd_pcm_lib_alloc_vmalloc_buffer()
402 * @offset: offset in the buffer
403 *
404 * This function is to be used as the page callback in the PCM ops.
405 *
406 * Return: The page struct, or %NULL on failure.
407 */
408struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
409 unsigned long offset)
410{
411 return vmalloc_to_page(substream->runtime->dma_area + offset);
412}
413EXPORT_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/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);