[linux-2.6-block.git] / sound / core / pcm_memory.c

/*
 *  Digital Audio (PCM) abstract layer
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/io.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/moduleparam.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/info.h>
#include <sound/initval.h>

static int preallocate_dma = 1;
module_param(preallocate_dma, int, 0444);
MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");

static int maximum_substreams = 4;
module_param(maximum_substreams, int, 0444);
MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");

static const size_t snd_minimum_buffer = 16384;


/*
 * try to allocate as the large pages as possible.
 * stores the resultant memory size in *res_size.
 *
 * the minimum size is snd_minimum_buffer.  it should be power of 2.
 */
static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
{
	struct snd_dma_buffer *dmab = &substream->dma_buffer;
	size_t orig_size = size;
	int err;

	do {
		if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
					       size, dmab)) < 0) {
			if (err != -ENOMEM)
				return err; /* fatal error */
		} else
			return 0;
		size >>= 1;
	} while (size >= snd_minimum_buffer);
	dmab->bytes = 0; /* tell error */
	pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
		substream->pcm->card->number, substream->pcm->device,
		substream->stream ? 'c' : 'p', substream->number,
		substream->pcm->name, orig_size);
	return 0;
}

/*
 * release the preallocated buffer if not yet done.
 */
static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
{
	if (substream->dma_buffer.area == NULL)
		return;
	snd_dma_free_pages(&substream->dma_buffer);
	substream->dma_buffer.area = NULL;
}

/**
 * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
 * @substream: the pcm substream instance
 *
 * Releases the pre-allocated buffer of the given substream.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
{
	snd_pcm_lib_preallocate_dma_free(substream);
#ifdef CONFIG_SND_VERBOSE_PROCFS
	snd_info_free_entry(substream->proc_prealloc_max_entry);
	substream->proc_prealloc_max_entry = NULL;
	snd_info_free_entry(substream->proc_prealloc_entry);
	substream->proc_prealloc_entry = NULL;
#endif
	return 0;
}

/**
 * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
 * @pcm: the pcm instance
 *
 * Releases all the pre-allocated buffers on the given pcm.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
{
	struct snd_pcm_substream *substream;
	int stream;

	for (stream = 0; stream < 2; stream++)
		for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
			snd_pcm_lib_preallocate_free(substream);
	return 0;
}

EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);

#ifdef CONFIG_SND_VERBOSE_PROCFS
/*
 * read callback for prealloc proc file
 *
 * prints the current allocated size in kB.
 */
static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
					      struct snd_info_buffer *buffer)
{
	struct snd_pcm_substream *substream = entry->private_data;
	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
}

/*
 * read callback for prealloc_max proc file
 *
 * prints the maximum allowed size in kB.
 */
static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
						  struct snd_info_buffer *buffer)
{
	struct snd_pcm_substream *substream = entry->private_data;
	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
}

/*
 * write callback for prealloc proc file
 *
 * accepts the preallocation size in kB.
 */
static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
					       struct snd_info_buffer *buffer)
{
	struct snd_pcm_substream *substream = entry->private_data;
	char line[64], str[64];
	size_t size;
	struct snd_dma_buffer new_dmab;

	if (substream->runtime) {
		buffer->error = -EBUSY;
		return;
	}
	if (!snd_info_get_line(buffer, line, sizeof(line))) {
		snd_info_get_str(str, line, sizeof(str));
		size = simple_strtoul(str, NULL, 10) * 1024;
		if ((size != 0 && size < 8192) || size > substream->dma_max) {
			buffer->error = -EINVAL;
			return;
		}
		if (substream->dma_buffer.bytes == size)
			return;
		memset(&new_dmab, 0, sizeof(new_dmab));
		new_dmab.dev = substream->dma_buffer.dev;
		if (size > 0) {
			if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
						substream->dma_buffer.dev.dev,
						size, &new_dmab) < 0) {
				buffer->error = -ENOMEM;
				return;
			}
			substream->buffer_bytes_max = size;
		} else {
			substream->buffer_bytes_max = UINT_MAX;
		}
		if (substream->dma_buffer.area)
			snd_dma_free_pages(&substream->dma_buffer);
		substream->dma_buffer = new_dmab;
	} else {
		buffer->error = -EINVAL;
	}
}

static inline void preallocate_info_init(struct snd_pcm_substream *substream)
{
	struct snd_info_entry *entry;

	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
		entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
		entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
		entry->mode |= S_IWUSR;
		entry->private_data = substream;
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	substream->proc_prealloc_entry = entry;
	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
		entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
		entry->private_data = substream;
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	substream->proc_prealloc_max_entry = entry;
}

#else /* !CONFIG_SND_VERBOSE_PROCFS */
#define preallocate_info_init(s)
#endif /* CONFIG_SND_VERBOSE_PROCFS */

/*
 * pre-allocate the buffer and create a proc file for the substream
 */
static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
					  size_t size, size_t max)
{

	if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
		preallocate_pcm_pages(substream, size);

	if (substream->dma_buffer.bytes > 0)
		substream->buffer_bytes_max = substream->dma_buffer.bytes;
	substream->dma_max = max;
	preallocate_info_init(substream);
	return 0;
}


/**
 * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
 * @substream: the pcm substream instance
 * @type: DMA type (SNDRV_DMA_TYPE_*)
 * @data: DMA type dependent data
 * @size: the requested pre-allocation size in bytes
 * @max: the max. allowed pre-allocation size
 *
 * Do pre-allocation for the given DMA buffer type.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
				  int type, struct device *data,
				  size_t size, size_t max)
{
	substream->dma_buffer.dev.type = type;
	substream->dma_buffer.dev.dev = data;
	return snd_pcm_lib_preallocate_pages1(substream, size, max);
}

EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);

/**
 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
 * @pcm: the pcm instance
 * @type: DMA type (SNDRV_DMA_TYPE_*)
 * @data: DMA type dependent data
 * @size: the requested pre-allocation size in bytes
 * @max: the max. allowed pre-allocation size
 *
 * Do pre-allocation to all substreams of the given pcm for the
 * specified DMA type.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
					  int type, void *data,
					  size_t size, size_t max)
{
	struct snd_pcm_substream *substream;
	int stream, err;

	for (stream = 0; stream < 2; stream++)
		for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
			if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
				return err;
	return 0;
}

EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);

#ifdef CONFIG_SND_DMA_SGBUF
/**
 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
 * @substream: the pcm substream instance
 * @offset: the buffer offset
 *
 * Used as the page callback of PCM ops.
 *
 * Return: The page struct at the given buffer offset. %NULL on failure.
 */
struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
{
	struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);

	unsigned int idx = offset >> PAGE_SHIFT;
	if (idx >= (unsigned int)sgbuf->pages)
		return NULL;
	return sgbuf->page_table[idx];
}

EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
#endif /* CONFIG_SND_DMA_SGBUF */

/**
 * snd_pcm_lib_malloc_pages - allocate the DMA buffer
 * @substream: the substream to allocate the DMA buffer to
 * @size: the requested buffer size in bytes
 *
 * Allocates the DMA buffer on the BUS type given earlier to
 * snd_pcm_lib_preallocate_xxx_pages().
 *
 * Return: 1 if the buffer is changed, 0 if not changed, or a negative
 * code on failure.
 */
int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
{
	struct snd_pcm_runtime *runtime;
	struct snd_dma_buffer *dmab = NULL;

	if (PCM_RUNTIME_CHECK(substream))
		return -EINVAL;
	if (snd_BUG_ON(substream->dma_buffer.dev.type ==
		       SNDRV_DMA_TYPE_UNKNOWN))
		return -EINVAL;
	runtime = substream->runtime;

	if (runtime->dma_buffer_p) {
		/* perphaps, we might free the large DMA memory region
		   to save some space here, but the actual solution
		   costs us less time */
		if (runtime->dma_buffer_p->bytes >= size) {
			runtime->dma_bytes = size;
			return 0;	/* ok, do not change */
		}
		snd_pcm_lib_free_pages(substream);
	}
	if (substream->dma_buffer.area != NULL &&
	    substream->dma_buffer.bytes >= size) {
		dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
	} else {
		dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
		if (! dmab)
			return -ENOMEM;
		dmab->dev = substream->dma_buffer.dev;
		if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
					substream->dma_buffer.dev.dev,
					size, dmab) < 0) {
			kfree(dmab);
			return -ENOMEM;
		}
	}
	snd_pcm_set_runtime_buffer(substream, dmab);
	runtime->dma_bytes = size;
	return 1;			/* area was changed */
}

EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);

/**
 * snd_pcm_lib_free_pages - release the allocated DMA buffer.
 * @substream: the substream to release the DMA buffer
 *
 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime;

	if (PCM_RUNTIME_CHECK(substream))
		return -EINVAL;
	runtime = substream->runtime;
	if (runtime->dma_area == NULL)
		return 0;
	if (runtime->dma_buffer_p != &substream->dma_buffer) {
		/* it's a newly allocated buffer.  release it now. */
		snd_dma_free_pages(runtime->dma_buffer_p);
		kfree(runtime->dma_buffer_p);
	}
	snd_pcm_set_runtime_buffer(substream, NULL);
	return 0;
}

EXPORT_SYMBOL(snd_pcm_lib_free_pages);

int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
				      size_t size, gfp_t gfp_flags)
{
	struct snd_pcm_runtime *runtime;

	if (PCM_RUNTIME_CHECK(substream))
		return -EINVAL;
	runtime = substream->runtime;
	if (runtime->dma_area) {
		if (runtime->dma_bytes >= size)
			return 0; /* already large enough */
		vfree(runtime->dma_area);
	}
	runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
	if (!runtime->dma_area)
		return -ENOMEM;
	runtime->dma_bytes = size;
	return 1;
}
EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);

/**
 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
 * @substream: the substream with a buffer allocated by
 *	snd_pcm_lib_alloc_vmalloc_buffer()
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime;

	if (PCM_RUNTIME_CHECK(substream))
		return -EINVAL;
	runtime = substream->runtime;
	vfree(runtime->dma_area);
	runtime->dma_area = NULL;
	return 0;
}
EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);

/**
 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
 * @substream: the substream with a buffer allocated by
 *	snd_pcm_lib_alloc_vmalloc_buffer()
 * @offset: offset in the buffer
 *
 * This function is to be used as the page callback in the PCM ops.
 *
 * Return: The page struct, or %NULL on failure.
 */
struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
					  unsigned long offset)
{
	return vmalloc_to_page(substream->runtime->dma_area + offset);
}
EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* Digital Audio (PCM) abstract layer
c1017a4c	3	* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
1da177e4 LT	4	*
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*
	20	*/
	21
6cbbfe1c	22	#include <linux/io.h>
1da177e4 LT	23	#include <linux/time.h>
1da177e4 LT	24	#include <linux/init.h>
5a0e3ad6	25	#include <linux/slab.h>
1da177e4	26	#include <linux/moduleparam.h>
ee7c343c	27	#include <linux/vmalloc.h>
d81a6d71	28	#include <linux/export.h>
1da177e4 LT	29	#include <sound/core.h>
	30	#include <sound/pcm.h>
	31	#include <sound/info.h>
	32	#include <sound/initval.h>
	33
	34	static int preallocate_dma = 1;
	35	module_param(preallocate_dma, int, 0444);
	36	MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
	37
	38	static int maximum_substreams = 4;
	39	module_param(maximum_substreams, int, 0444);
	40	MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
	41
	42	static const size_t snd_minimum_buffer = 16384;
	43
	44
	45	/*
	46	* try to allocate as the large pages as possible.
	47	* stores the resultant memory size in *res_size.
	48	*
	49	* the minimum size is snd_minimum_buffer. it should be power of 2.
	50	*/
877211f5	51	static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
1da177e4 LT	52	{
1da177e4 LT	53	struct snd_dma_buffer *dmab = &substream->dma_buffer;
6ab08ced	54	size_t orig_size = size;
1da177e4 LT	55	int err;
1da177e4 LT	56
1da177e4 LT	57	do {
	58	if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
	59	size, dmab)) < 0) {
	60	if (err != -ENOMEM)
	61	return err; /* fatal error */
	62	} else
	63	return 0;
	64	size >>= 1;
	65	} while (size >= snd_minimum_buffer);
	66	dmab->bytes = 0; /* tell error */
6ab08ced TI	67	pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
	68	substream->pcm->card->number, substream->pcm->device,
	69	substream->stream ? 'c' : 'p', substream->number,
	70	substream->pcm->name, orig_size);
1da177e4 LT	71	return 0;
	72	}
	73
	74	/*
	75	* release the preallocated buffer if not yet done.
	76	*/
877211f5	77	static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
1da177e4 LT	78	{
	79	if (substream->dma_buffer.area == NULL)
	80	return;
47d98c02	81	snd_dma_free_pages(&substream->dma_buffer);
1da177e4 LT	82	substream->dma_buffer.area = NULL;
	83	}
	84
	85	/**
	86	* snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
	87	* @substream: the pcm substream instance
	88	*
	89	* Releases the pre-allocated buffer of the given substream.
	90	*
eb7c06e8	91	* Return: Zero if successful, or a negative error code on failure.
1da177e4	92	*/
877211f5	93	int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
1da177e4 LT	94	{
1da177e4 LT	95	snd_pcm_lib_preallocate_dma_free(substream);
b7d90a35	96	#ifdef CONFIG_SND_VERBOSE_PROCFS
c7132aeb JK	97	snd_info_free_entry(substream->proc_prealloc_max_entry);
c7132aeb JK	98	substream->proc_prealloc_max_entry = NULL;
746d4a02	99	snd_info_free_entry(substream->proc_prealloc_entry);
e28563cc	100	substream->proc_prealloc_entry = NULL;
b7d90a35	101	#endif
1da177e4 LT	102	return 0;
	103	}
	104
	105	/**
	106	* snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
	107	* @pcm: the pcm instance
	108	*
	109	* Releases all the pre-allocated buffers on the given pcm.
	110	*
eb7c06e8	111	* Return: Zero if successful, or a negative error code on failure.
1da177e4	112	*/
877211f5	113	int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
1da177e4	114	{
877211f5	115	struct snd_pcm_substream *substream;
1da177e4 LT	116	int stream;
	117
	118	for (stream = 0; stream < 2; stream++)
	119	for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
	120	snd_pcm_lib_preallocate_free(substream);
	121	return 0;
	122	}
	123
e88e8ae6 TI	124	EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
e88e8ae6 TI	125
b7d90a35	126	#ifdef CONFIG_SND_VERBOSE_PROCFS
1da177e4 LT	127	/*
	128	* read callback for prealloc proc file
	129	*
	130	* prints the current allocated size in kB.
	131	*/
877211f5 TI	132	static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
877211f5 TI	133	struct snd_info_buffer *buffer)
1da177e4	134	{
877211f5	135	struct snd_pcm_substream *substream = entry->private_data;
1da177e4 LT	136	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
	137	}
	138
c7132aeb JK	139	/*
	140	* read callback for prealloc_max proc file
	141	*
	142	* prints the maximum allowed size in kB.
	143	*/
	144	static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
	145	struct snd_info_buffer *buffer)
	146	{
	147	struct snd_pcm_substream *substream = entry->private_data;
	148	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
	149	}
	150
1da177e4 LT	151	/*
	152	* write callback for prealloc proc file
	153	*
	154	* accepts the preallocation size in kB.
	155	*/
877211f5 TI	156	static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
877211f5 TI	157	struct snd_info_buffer *buffer)
1da177e4	158	{
877211f5	159	struct snd_pcm_substream *substream = entry->private_data;
1da177e4 LT	160	char line[64], str[64];
	161	size_t size;
	162	struct snd_dma_buffer new_dmab;
	163
	164	if (substream->runtime) {
	165	buffer->error = -EBUSY;
	166	return;
	167	}
	168	if (!snd_info_get_line(buffer, line, sizeof(line))) {
	169	snd_info_get_str(str, line, sizeof(str));
	170	size = simple_strtoul(str, NULL, 10) * 1024;
	171	if ((size != 0 && size < 8192) \|\| size > substream->dma_max) {
	172	buffer->error = -EINVAL;
	173	return;
	174	}
	175	if (substream->dma_buffer.bytes == size)
	176	return;
	177	memset(&new_dmab, 0, sizeof(new_dmab));
	178	new_dmab.dev = substream->dma_buffer.dev;
	179	if (size > 0) {
	180	if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
	181	substream->dma_buffer.dev.dev,
	182	size, &new_dmab) < 0) {
	183	buffer->error = -ENOMEM;
	184	return;
	185	}
	186	substream->buffer_bytes_max = size;
	187	} else {
	188	substream->buffer_bytes_max = UINT_MAX;
	189	}
	190	if (substream->dma_buffer.area)
	191	snd_dma_free_pages(&substream->dma_buffer);
	192	substream->dma_buffer = new_dmab;
	193	} else {
	194	buffer->error = -EINVAL;
	195	}
	196	}
	197
e28563cc	198	static inline void preallocate_info_init(struct snd_pcm_substream *substream)
1da177e4	199	{
877211f5	200	struct snd_info_entry *entry;
1da177e4	201
1da177e4	202	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
1da177e4	203	entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
1da177e4	204	entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
bd7bf042	205	entry->mode \|= S_IWUSR;
1da177e4 LT	206	entry->private_data = substream;
	207	if (snd_info_register(entry) < 0) {
	208	snd_info_free_entry(entry);
	209	entry = NULL;
	210	}
	211	}
	212	substream->proc_prealloc_entry = entry;
c7132aeb JK	213	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
	214	entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
	215	entry->private_data = substream;
	216	if (snd_info_register(entry) < 0) {
	217	snd_info_free_entry(entry);
	218	entry = NULL;
	219	}
	220	}
	221	substream->proc_prealloc_max_entry = entry;
e28563cc TI	222	}
e28563cc TI	223
b7d90a35	224	#else /* !CONFIG_SND_VERBOSE_PROCFS */
e28563cc	225	#define preallocate_info_init(s)
b7d90a35	226	#endif /* CONFIG_SND_VERBOSE_PROCFS */
e28563cc TI	227
	228	/*
	229	* pre-allocate the buffer and create a proc file for the substream
	230	*/
	231	static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
	232	size_t size, size_t max)
	233	{
	234
	235	if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
	236	preallocate_pcm_pages(substream, size);
	237
	238	if (substream->dma_buffer.bytes > 0)
	239	substream->buffer_bytes_max = substream->dma_buffer.bytes;
	240	substream->dma_max = max;
	241	preallocate_info_init(substream);
1da177e4 LT	242	return 0;
	243	}
	244
	245
	246	/**
	247	* snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
	248	* @substream: the pcm substream instance
	249	* @type: DMA type (SNDRV_DMA_TYPE_*)
25985edc	250	* @data: DMA type dependent data
1da177e4 LT	251	* @size: the requested pre-allocation size in bytes
	252	* @max: the max. allowed pre-allocation size
	253	*
	254	* Do pre-allocation for the given DMA buffer type.
	255	*
eb7c06e8	256	* Return: Zero if successful, or a negative error code on failure.
1da177e4	257	*/
877211f5	258	int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
1da177e4 LT	259	int type, struct device *data,
	260	size_t size, size_t max)
	261	{
	262	substream->dma_buffer.dev.type = type;
	263	substream->dma_buffer.dev.dev = data;
	264	return snd_pcm_lib_preallocate_pages1(substream, size, max);
	265	}
	266
e88e8ae6 TI	267	EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
e88e8ae6 TI	268
1da177e4	269	/**
25985edc	270	* snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
df8db936	271	* @pcm: the pcm instance
1da177e4	272	* @type: DMA type (SNDRV_DMA_TYPE_*)
25985edc	273	* @data: DMA type dependent data
1da177e4 LT	274	* @size: the requested pre-allocation size in bytes
	275	* @max: the max. allowed pre-allocation size
	276	*
	277	* Do pre-allocation to all substreams of the given pcm for the
	278	* specified DMA type.
	279	*
eb7c06e8	280	* Return: Zero if successful, or a negative error code on failure.
1da177e4	281	*/
877211f5	282	int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
1da177e4 LT	283	int type, void *data,
	284	size_t size, size_t max)
	285	{
877211f5	286	struct snd_pcm_substream *substream;
1da177e4 LT	287	int stream, err;
	288
	289	for (stream = 0; stream < 2; stream++)
	290	for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
	291	if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
	292	return err;
	293	return 0;
	294	}
	295
e88e8ae6 TI	296	EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
e88e8ae6 TI	297
cc6a8acd	298	#ifdef CONFIG_SND_DMA_SGBUF
1da177e4 LT	299	/**
	300	* snd_pcm_sgbuf_ops_page - get the page struct at the given offset
	301	* @substream: the pcm substream instance
	302	* @offset: the buffer offset
	303	*
1da177e4	304	* Used as the page callback of PCM ops.
eb7c06e8 YB	305	*
eb7c06e8 YB	306	* Return: The page struct at the given buffer offset. %NULL on failure.
1da177e4	307	*/
877211f5	308	struct page snd_pcm_sgbuf_ops_page(struct snd_pcm_substream substream, unsigned long offset)
1da177e4 LT	309	{
	310	struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
	311
	312	unsigned int idx = offset >> PAGE_SHIFT;
	313	if (idx >= (unsigned int)sgbuf->pages)
	314	return NULL;
	315	return sgbuf->page_table[idx];
	316	}
	317
e88e8ae6	318	EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
cc6a8acd	319	#endif /* CONFIG_SND_DMA_SGBUF */
51e9f2e6	320
1da177e4 LT	321	/**
	322	* snd_pcm_lib_malloc_pages - allocate the DMA buffer
	323	* @substream: the substream to allocate the DMA buffer to
	324	* @size: the requested buffer size in bytes
	325	*
	326	* Allocates the DMA buffer on the BUS type given earlier to
	327	* snd_pcm_lib_preallocate_xxx_pages().
	328	*
eb7c06e8	329	* Return: 1 if the buffer is changed, 0 if not changed, or a negative
1da177e4 LT	330	* code on failure.
1da177e4 LT	331	*/
877211f5	332	int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
1da177e4	333	{
877211f5	334	struct snd_pcm_runtime *runtime;
1da177e4 LT	335	struct snd_dma_buffer *dmab = NULL;
1da177e4 LT	336
7eaa943c TI	337	if (PCM_RUNTIME_CHECK(substream))
	338	return -EINVAL;
	339	if (snd_BUG_ON(substream->dma_buffer.dev.type ==
	340	SNDRV_DMA_TYPE_UNKNOWN))
	341	return -EINVAL;
1da177e4	342	runtime = substream->runtime;
1da177e4 LT	343
	344	if (runtime->dma_buffer_p) {
	345	/* perphaps, we might free the large DMA memory region
	346	to save some space here, but the actual solution
	347	costs us less time */
	348	if (runtime->dma_buffer_p->bytes >= size) {
	349	runtime->dma_bytes = size;
	350	return 0; /* ok, do not change */
	351	}
	352	snd_pcm_lib_free_pages(substream);
	353	}
877211f5 TI	354	if (substream->dma_buffer.area != NULL &&
877211f5 TI	355	substream->dma_buffer.bytes >= size) {
1da177e4 LT	356	dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
1da177e4 LT	357	} else {
ca2c0966	358	dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
1da177e4 LT	359	if (! dmab)
	360	return -ENOMEM;
	361	dmab->dev = substream->dma_buffer.dev;
	362	if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
	363	substream->dma_buffer.dev.dev,
	364	size, dmab) < 0) {
	365	kfree(dmab);
	366	return -ENOMEM;
	367	}
	368	}
	369	snd_pcm_set_runtime_buffer(substream, dmab);
	370	runtime->dma_bytes = size;
	371	return 1; /* area was changed */
	372	}
	373
e88e8ae6 TI	374	EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
e88e8ae6 TI	375
1da177e4 LT	376	/**
	377	* snd_pcm_lib_free_pages - release the allocated DMA buffer.
	378	* @substream: the substream to release the DMA buffer
	379	*
	380	* Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
	381	*
eb7c06e8	382	* Return: Zero if successful, or a negative error code on failure.
1da177e4	383	*/
877211f5	384	int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
1da177e4	385	{
877211f5	386	struct snd_pcm_runtime *runtime;
1da177e4	387
7eaa943c TI	388	if (PCM_RUNTIME_CHECK(substream))
7eaa943c TI	389	return -EINVAL;
1da177e4	390	runtime = substream->runtime;
1da177e4 LT	391	if (runtime->dma_area == NULL)
	392	return 0;
	393	if (runtime->dma_buffer_p != &substream->dma_buffer) {
	394	/* it's a newly allocated buffer. release it now. */
	395	snd_dma_free_pages(runtime->dma_buffer_p);
	396	kfree(runtime->dma_buffer_p);
	397	}
	398	snd_pcm_set_runtime_buffer(substream, NULL);
	399	return 0;
	400	}
e88e8ae6 TI	401
e88e8ae6 TI	402	EXPORT_SYMBOL(snd_pcm_lib_free_pages);
681b84e1 CL	403
	404	int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
	405	size_t size, gfp_t gfp_flags)
	406	{
	407	struct snd_pcm_runtime *runtime;
	408
	409	if (PCM_RUNTIME_CHECK(substream))
	410	return -EINVAL;
	411	runtime = substream->runtime;
	412	if (runtime->dma_area) {
	413	if (runtime->dma_bytes >= size)
	414	return 0; /* already large enough */
	415	vfree(runtime->dma_area);
	416	}
	417	runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
	418	if (!runtime->dma_area)
	419	return -ENOMEM;
	420	runtime->dma_bytes = size;
	421	return 1;
	422	}
	423	EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
	424
	425	/**
	426	* snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
	427	* @substream: the substream with a buffer allocated by
	428	* snd_pcm_lib_alloc_vmalloc_buffer()
eb7c06e8 YB	429	*
eb7c06e8 YB	430	* Return: Zero if successful, or a negative error code on failure.
681b84e1 CL	431	*/
	432	int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
	433	{
	434	struct snd_pcm_runtime *runtime;
	435
	436	if (PCM_RUNTIME_CHECK(substream))
	437	return -EINVAL;
	438	runtime = substream->runtime;
	439	vfree(runtime->dma_area);
	440	runtime->dma_area = NULL;
	441	return 0;
	442	}
	443	EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
	444
	445	/**
	446	* snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
	447	* @substream: the substream with a buffer allocated by
	448	* snd_pcm_lib_alloc_vmalloc_buffer()
	449	* @offset: offset in the buffer
	450	*
	451	* This function is to be used as the page callback in the PCM ops.
eb7c06e8 YB	452	*
eb7c06e8 YB	453	* Return: The page struct, or %NULL on failure.
681b84e1 CL	454	*/
	455	struct page snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream substream,
	456	unsigned long offset)
	457	{
	458	return vmalloc_to_page(substream->runtime->dma_area + offset);
	459	}
	460	EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);