Linux Audio

Check our new training course

Loading...
v5.4
  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);
v5.9
  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);