[net-next-2.6.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 <sound/driver.h>
#include <asm/io.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/moduleparam.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;
	int err;

	snd_assert(size > 0, return -EINVAL);

	/* already reserved? */
	if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) {
		if (dmab->bytes >= size)
			return 0; /* yes */
		/* no, free the reserved block */
		snd_dma_free_pages(dmab);
		dmab->bytes = 0;
	}

	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 */
	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;
	if (substream->dma_buf_id)
		snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id);
	else
		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.
 *
 * Returns 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.
 *
 * Returns 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 dependant 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.
 *
 * When substream->dma_buf_id is set, the function tries to look for
 * the reserved buffer, and the buffer is not freed but reserved at
 * destruction time.  The dma_buf_id must be unique for all systems
 * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
 *
 * Returns 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 continous memory type (all substreams)
 * @pcm: the pcm instance
 * @type: DMA type (SNDRV_DMA_TYPE_*)
 * @data: DMA type dependant 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.
 *
 * Returns 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);

/**
 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
 * @substream: the pcm substream instance
 * @offset: the buffer offset
 *
 * Returns the page struct at the given buffer offset.
 * Used as the page callback of PCM ops.
 */
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);

/**
 * 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().
 *
 * Returns 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;

	snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL);
	snd_assert(substream != NULL, return -EINVAL);
	runtime = substream->runtime;
	snd_assert(runtime != NULL, return -EINVAL);

	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().
 *
 * Returns 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;

	snd_assert(substream != NULL, return -EINVAL);
	runtime = substream->runtime;
	snd_assert(runtime != NULL, return -EINVAL);
	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);
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
	22	#include <sound/driver.h>
	23	#include <asm/io.h>
	24	#include <linux/time.h>
	25	#include <linux/init.h>
	26	#include <linux/moduleparam.h>
	27	#include <sound/core.h>
	28	#include <sound/pcm.h>
	29	#include <sound/info.h>
	30	#include <sound/initval.h>
	31
	32	static int preallocate_dma = 1;
	33	module_param(preallocate_dma, int, 0444);
	34	MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
	35
	36	static int maximum_substreams = 4;
	37	module_param(maximum_substreams, int, 0444);
	38	MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
	39
	40	static const size_t snd_minimum_buffer = 16384;
	41
	42
	43	/*
	44	* try to allocate as the large pages as possible.
	45	* stores the resultant memory size in *res_size.
	46	*
	47	* the minimum size is snd_minimum_buffer. it should be power of 2.
	48	*/
877211f5	49	static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
1da177e4 LT	50	{
	51	struct snd_dma_buffer *dmab = &substream->dma_buffer;
	52	int err;
	53
	54	snd_assert(size > 0, return -EINVAL);
	55
	56	/* already reserved? */
	57	if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) {
	58	if (dmab->bytes >= size)
	59	return 0; /* yes */
	60	/* no, free the reserved block */
	61	snd_dma_free_pages(dmab);
	62	dmab->bytes = 0;
	63	}
	64
	65	do {
	66	if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
	67	size, dmab)) < 0) {
	68	if (err != -ENOMEM)
	69	return err; /* fatal error */
	70	} else
	71	return 0;
	72	size >>= 1;
	73	} while (size >= snd_minimum_buffer);
	74	dmab->bytes = 0; /* tell error */
	75	return 0;
	76	}
	77
	78	/*
	79	* release the preallocated buffer if not yet done.
	80	*/
877211f5	81	static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
1da177e4 LT	82	{
	83	if (substream->dma_buffer.area == NULL)
	84	return;
	85	if (substream->dma_buf_id)
	86	snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id);
	87	else
	88	snd_dma_free_pages(&substream->dma_buffer);
	89	substream->dma_buffer.area = NULL;
	90	}
	91
	92	/**
	93	* snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
	94	* @substream: the pcm substream instance
	95	*
	96	* Releases the pre-allocated buffer of the given substream.
	97	*
	98	* Returns zero if successful, or a negative error code on failure.
	99	*/
877211f5	100	int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
1da177e4 LT	101	{
1da177e4 LT	102	snd_pcm_lib_preallocate_dma_free(substream);
b7d90a35	103	#ifdef CONFIG_SND_VERBOSE_PROCFS
c7132aeb JK	104	snd_info_free_entry(substream->proc_prealloc_max_entry);
c7132aeb JK	105	substream->proc_prealloc_max_entry = NULL;
746d4a02	106	snd_info_free_entry(substream->proc_prealloc_entry);
e28563cc	107	substream->proc_prealloc_entry = NULL;
b7d90a35	108	#endif
1da177e4 LT	109	return 0;
	110	}
	111
	112	/**
	113	* snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
	114	* @pcm: the pcm instance
	115	*
	116	* Releases all the pre-allocated buffers on the given pcm.
	117	*
	118	* Returns zero if successful, or a negative error code on failure.
	119	*/
877211f5	120	int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
1da177e4	121	{
877211f5	122	struct snd_pcm_substream *substream;
1da177e4 LT	123	int stream;
	124
	125	for (stream = 0; stream < 2; stream++)
	126	for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
	127	snd_pcm_lib_preallocate_free(substream);
	128	return 0;
	129	}
	130
e88e8ae6 TI	131	EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
e88e8ae6 TI	132
b7d90a35	133	#ifdef CONFIG_SND_VERBOSE_PROCFS
1da177e4 LT	134	/*
	135	* read callback for prealloc proc file
	136	*
	137	* prints the current allocated size in kB.
	138	*/
877211f5 TI	139	static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
877211f5 TI	140	struct snd_info_buffer *buffer)
1da177e4	141	{
877211f5	142	struct snd_pcm_substream *substream = entry->private_data;
1da177e4 LT	143	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
	144	}
	145
c7132aeb JK	146	/*
	147	* read callback for prealloc_max proc file
	148	*
	149	* prints the maximum allowed size in kB.
	150	*/
	151	static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
	152	struct snd_info_buffer *buffer)
	153	{
	154	struct snd_pcm_substream *substream = entry->private_data;
	155	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
	156	}
	157
1da177e4 LT	158	/*
	159	* write callback for prealloc proc file
	160	*
	161	* accepts the preallocation size in kB.
	162	*/
877211f5 TI	163	static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
877211f5 TI	164	struct snd_info_buffer *buffer)
1da177e4	165	{
877211f5	166	struct snd_pcm_substream *substream = entry->private_data;
1da177e4 LT	167	char line[64], str[64];
	168	size_t size;
	169	struct snd_dma_buffer new_dmab;
	170
	171	if (substream->runtime) {
	172	buffer->error = -EBUSY;
	173	return;
	174	}
	175	if (!snd_info_get_line(buffer, line, sizeof(line))) {
	176	snd_info_get_str(str, line, sizeof(str));
	177	size = simple_strtoul(str, NULL, 10) * 1024;
	178	if ((size != 0 && size < 8192) \|\| size > substream->dma_max) {
	179	buffer->error = -EINVAL;
	180	return;
	181	}
	182	if (substream->dma_buffer.bytes == size)
	183	return;
	184	memset(&new_dmab, 0, sizeof(new_dmab));
	185	new_dmab.dev = substream->dma_buffer.dev;
	186	if (size > 0) {
	187	if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
	188	substream->dma_buffer.dev.dev,
	189	size, &new_dmab) < 0) {
	190	buffer->error = -ENOMEM;
	191	return;
	192	}
	193	substream->buffer_bytes_max = size;
	194	} else {
	195	substream->buffer_bytes_max = UINT_MAX;
	196	}
	197	if (substream->dma_buffer.area)
	198	snd_dma_free_pages(&substream->dma_buffer);
	199	substream->dma_buffer = new_dmab;
	200	} else {
	201	buffer->error = -EINVAL;
	202	}
	203	}
	204
e28563cc	205	static inline void preallocate_info_init(struct snd_pcm_substream *substream)
1da177e4	206	{
877211f5	207	struct snd_info_entry *entry;
1da177e4	208
1da177e4	209	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
1da177e4	210	entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
1da177e4	211	entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
bd7bf042	212	entry->mode \|= S_IWUSR;
1da177e4 LT	213	entry->private_data = substream;
	214	if (snd_info_register(entry) < 0) {
	215	snd_info_free_entry(entry);
	216	entry = NULL;
	217	}
	218	}
	219	substream->proc_prealloc_entry = entry;
c7132aeb JK	220	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
	221	entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
	222	entry->private_data = substream;
	223	if (snd_info_register(entry) < 0) {
	224	snd_info_free_entry(entry);
	225	entry = NULL;
	226	}
	227	}
	228	substream->proc_prealloc_max_entry = entry;
e28563cc TI	229	}
e28563cc TI	230
b7d90a35	231	#else /* !CONFIG_SND_VERBOSE_PROCFS */
e28563cc	232	#define preallocate_info_init(s)
b7d90a35	233	#endif /* CONFIG_SND_VERBOSE_PROCFS */
e28563cc TI	234
	235	/*
	236	* pre-allocate the buffer and create a proc file for the substream
	237	*/
	238	static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
	239	size_t size, size_t max)
	240	{
	241
	242	if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
	243	preallocate_pcm_pages(substream, size);
	244
	245	if (substream->dma_buffer.bytes > 0)
	246	substream->buffer_bytes_max = substream->dma_buffer.bytes;
	247	substream->dma_max = max;
	248	preallocate_info_init(substream);
1da177e4 LT	249	return 0;
	250	}
	251
	252
	253	/**
	254	* snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
	255	* @substream: the pcm substream instance
	256	* @type: DMA type (SNDRV_DMA_TYPE_*)
	257	* @data: DMA type dependant data
	258	* @size: the requested pre-allocation size in bytes
	259	* @max: the max. allowed pre-allocation size
	260	*
	261	* Do pre-allocation for the given DMA buffer type.
	262	*
	263	* When substream->dma_buf_id is set, the function tries to look for
	264	* the reserved buffer, and the buffer is not freed but reserved at
	265	* destruction time. The dma_buf_id must be unique for all systems
	266	* (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
	267	*
	268	* Returns zero if successful, or a negative error code on failure.
	269	*/
877211f5	270	int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
1da177e4 LT	271	int type, struct device *data,
	272	size_t size, size_t max)
	273	{
	274	substream->dma_buffer.dev.type = type;
	275	substream->dma_buffer.dev.dev = data;
	276	return snd_pcm_lib_preallocate_pages1(substream, size, max);
	277	}
	278
e88e8ae6 TI	279	EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
e88e8ae6 TI	280
1da177e4 LT	281	/**
1da177e4 LT	282	* snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams)
df8db936	283	* @pcm: the pcm instance
1da177e4 LT	284	* @type: DMA type (SNDRV_DMA_TYPE_*)
	285	* @data: DMA type dependant data
	286	* @size: the requested pre-allocation size in bytes
	287	* @max: the max. allowed pre-allocation size
	288	*
	289	* Do pre-allocation to all substreams of the given pcm for the
	290	* specified DMA type.
	291	*
	292	* Returns zero if successful, or a negative error code on failure.
	293	*/
877211f5	294	int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
1da177e4 LT	295	int type, void *data,
	296	size_t size, size_t max)
	297	{
877211f5	298	struct snd_pcm_substream *substream;
1da177e4 LT	299	int stream, err;
	300
	301	for (stream = 0; stream < 2; stream++)
	302	for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
	303	if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
	304	return err;
	305	return 0;
	306	}
	307
e88e8ae6 TI	308	EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
e88e8ae6 TI	309
1da177e4 LT	310	/**
	311	* snd_pcm_sgbuf_ops_page - get the page struct at the given offset
	312	* @substream: the pcm substream instance
	313	* @offset: the buffer offset
	314	*
	315	* Returns the page struct at the given buffer offset.
	316	* Used as the page callback of PCM ops.
	317	*/
877211f5	318	struct page snd_pcm_sgbuf_ops_page(struct snd_pcm_substream substream, unsigned long offset)
1da177e4 LT	319	{
	320	struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
	321
	322	unsigned int idx = offset >> PAGE_SHIFT;
	323	if (idx >= (unsigned int)sgbuf->pages)
	324	return NULL;
	325	return sgbuf->page_table[idx];
	326	}
	327
e88e8ae6 TI	328	EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
e88e8ae6 TI	329
1da177e4 LT	330	/**
	331	* snd_pcm_lib_malloc_pages - allocate the DMA buffer
	332	* @substream: the substream to allocate the DMA buffer to
	333	* @size: the requested buffer size in bytes
	334	*
	335	* Allocates the DMA buffer on the BUS type given earlier to
	336	* snd_pcm_lib_preallocate_xxx_pages().
	337	*
	338	* Returns 1 if the buffer is changed, 0 if not changed, or a negative
	339	* code on failure.
	340	*/
877211f5	341	int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
1da177e4	342	{
877211f5	343	struct snd_pcm_runtime *runtime;
1da177e4 LT	344	struct snd_dma_buffer *dmab = NULL;
	345
	346	snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL);
	347	snd_assert(substream != NULL, return -EINVAL);
	348	runtime = substream->runtime;
	349	snd_assert(runtime != NULL, return -EINVAL);
	350
	351	if (runtime->dma_buffer_p) {
	352	/* perphaps, we might free the large DMA memory region
	353	to save some space here, but the actual solution
	354	costs us less time */
	355	if (runtime->dma_buffer_p->bytes >= size) {
	356	runtime->dma_bytes = size;
	357	return 0; /* ok, do not change */
	358	}
	359	snd_pcm_lib_free_pages(substream);
	360	}
877211f5 TI	361	if (substream->dma_buffer.area != NULL &&
877211f5 TI	362	substream->dma_buffer.bytes >= size) {
1da177e4 LT	363	dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
1da177e4 LT	364	} else {
ca2c0966	365	dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
1da177e4 LT	366	if (! dmab)
	367	return -ENOMEM;
	368	dmab->dev = substream->dma_buffer.dev;
	369	if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
	370	substream->dma_buffer.dev.dev,
	371	size, dmab) < 0) {
	372	kfree(dmab);
	373	return -ENOMEM;
	374	}
	375	}
	376	snd_pcm_set_runtime_buffer(substream, dmab);
	377	runtime->dma_bytes = size;
	378	return 1; /* area was changed */
	379	}
	380
e88e8ae6 TI	381	EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
e88e8ae6 TI	382
1da177e4 LT	383	/**
	384	* snd_pcm_lib_free_pages - release the allocated DMA buffer.
	385	* @substream: the substream to release the DMA buffer
	386	*
	387	* Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
	388	*
	389	* Returns zero if successful, or a negative error code on failure.
	390	*/
877211f5	391	int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
1da177e4	392	{
877211f5	393	struct snd_pcm_runtime *runtime;
1da177e4 LT	394
	395	snd_assert(substream != NULL, return -EINVAL);
	396	runtime = substream->runtime;
	397	snd_assert(runtime != NULL, return -EINVAL);
	398	if (runtime->dma_area == NULL)
	399	return 0;
	400	if (runtime->dma_buffer_p != &substream->dma_buffer) {
	401	/* it's a newly allocated buffer. release it now. */
	402	snd_dma_free_pages(runtime->dma_buffer_p);
	403	kfree(runtime->dma_buffer_p);
	404	}
	405	snd_pcm_set_runtime_buffer(substream, NULL);
	406	return 0;
	407	}
e88e8ae6 TI	408
e88e8ae6 TI	409	EXPORT_SYMBOL(snd_pcm_lib_free_pages);