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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Digital Audio (PCM) abstract layer
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#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.
 */
void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
{
	snd_pcm_lib_preallocate_dma_free(substream);
}

/**
 * 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.
 */
void 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);
}
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;

	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
					   substream->proc_root);
	if (entry) {
		snd_info_set_text_ops(entry, substream,
				      snd_pcm_lib_preallocate_proc_read);
		entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
		entry->mode |= 0200;
	}
	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
					   substream->proc_root);
	if (entry)
		snd_info_set_text_ops(entry, substream,
				      snd_pcm_lib_preallocate_max_proc_read);
}

#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 void 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);
}


/**
 * 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.
 */
void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
				  int type, struct device *data,
				  size_t size, size_t max)
{
	if (snd_BUG_ON(substream->dma_buffer.dev.type))
		return;
	substream->dma_buffer.dev.type = type;
	substream->dma_buffer.dev.dev = data;
	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.
 */
void 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;

	for (stream = 0; stream < 2; stream++)
		for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
			snd_pcm_lib_preallocate_pages(substream, type, data, size, max);
}
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
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
1da177e4 LT	3	* Digital Audio (PCM) abstract layer
c1017a4c	4	* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
1da177e4 LT	5	*/
1da177e4 LT	6
6cbbfe1c	7	#include <linux/io.h>
1da177e4 LT	8	#include <linux/time.h>
1da177e4 LT	9	#include <linux/init.h>
5a0e3ad6	10	#include <linux/slab.h>
1da177e4	11	#include <linux/moduleparam.h>
ee7c343c	12	#include <linux/vmalloc.h>
d81a6d71	13	#include <linux/export.h>
1da177e4 LT	14	#include <sound/core.h>
	15	#include <sound/pcm.h>
	16	#include <sound/info.h>
	17	#include <sound/initval.h>
	18
	19	static int preallocate_dma = 1;
	20	module_param(preallocate_dma, int, 0444);
	21	MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
	22
	23	static int maximum_substreams = 4;
	24	module_param(maximum_substreams, int, 0444);
	25	MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
	26
	27	static 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	*/
877211f5	36	static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
1da177e4 LT	37	{
1da177e4 LT	38	struct snd_dma_buffer *dmab = &substream->dma_buffer;
6ab08ced	39	size_t orig_size = size;
1da177e4 LT	40	int err;
1da177e4 LT	41
1da177e4 LT	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 */
6ab08ced TI	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);
1da177e4 LT	56	return 0;
	57	}
	58
	59	/*
	60	* release the preallocated buffer if not yet done.
	61	*/
877211f5	62	static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
1da177e4 LT	63	{
	64	if (substream->dma_buffer.area == NULL)
	65	return;
47d98c02	66	snd_dma_free_pages(&substream->dma_buffer);
1da177e4 LT	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.
1da177e4	75	*/
bb580602	76	void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
1da177e4 LT	77	{
1da177e4 LT	78	snd_pcm_lib_preallocate_dma_free(substream);
1da177e4 LT	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.
1da177e4	86	*/
bb580602	87	void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
1da177e4	88	{
877211f5	89	struct snd_pcm_substream *substream;
1da177e4 LT	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);
1da177e4	95	}
e88e8ae6 TI	96	EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
e88e8ae6 TI	97
b7d90a35	98	#ifdef CONFIG_SND_VERBOSE_PROCFS
1da177e4 LT	99	/*
	100	* read callback for prealloc proc file
	101	*
	102	* prints the current allocated size in kB.
	103	*/
877211f5 TI	104	static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
877211f5 TI	105	struct snd_info_buffer *buffer)
1da177e4	106	{
877211f5	107	struct snd_pcm_substream *substream = entry->private_data;
1da177e4 LT	108	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
	109	}
	110
c7132aeb JK	111	/*
	112	* read callback for prealloc_max proc file
	113	*
	114	* prints the maximum allowed size in kB.
	115	*/
	116	static 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
1da177e4 LT	123	/*
	124	* write callback for prealloc proc file
	125	*
	126	* accepts the preallocation size in kB.
	127	*/
877211f5 TI	128	static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
877211f5 TI	129	struct snd_info_buffer *buffer)
1da177e4	130	{
877211f5	131	struct snd_pcm_substream *substream = entry->private_data;
1da177e4 LT	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
e28563cc	170	static inline void preallocate_info_init(struct snd_pcm_substream *substream)
1da177e4	171	{
877211f5	172	struct snd_info_entry *entry;
1da177e4	173
a8d14981 TI	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);
1da177e4	179	entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
6a73cf46	180	entry->mode \|= 0200;
c7132aeb	181	}
a8d14981 TI	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);
e28563cc TI	187	}
e28563cc TI	188
b7d90a35	189	#else /* !CONFIG_SND_VERBOSE_PROCFS */
e28563cc	190	#define preallocate_info_init(s)
b7d90a35	191	#endif /* CONFIG_SND_VERBOSE_PROCFS */
e28563cc TI	192
	193	/*
	194	* pre-allocate the buffer and create a proc file for the substream
	195	*/
bb580602	196	static void snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
e28563cc TI	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);
1da177e4 LT	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_*)
25985edc	214	* @data: DMA type dependent data
1da177e4 LT	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.
1da177e4	219	*/
bb580602	220	void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
1da177e4 LT	221	int type, struct device *data,
	222	size_t size, size_t max)
	223	{
a55eaf17 TI	224	if (snd_BUG_ON(substream->dma_buffer.dev.type))
a55eaf17 TI	225	return;
1da177e4 LT	226	substream->dma_buffer.dev.type = type;
1da177e4 LT	227	substream->dma_buffer.dev.dev = data;
bb580602	228	snd_pcm_lib_preallocate_pages1(substream, size, max);
1da177e4	229	}
e88e8ae6 TI	230	EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
e88e8ae6 TI	231
1da177e4	232	/**
25985edc	233	* snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
df8db936	234	* @pcm: the pcm instance
1da177e4	235	* @type: DMA type (SNDRV_DMA_TYPE_*)
25985edc	236	* @data: DMA type dependent data
1da177e4 LT	237	* @size: the requested pre-allocation size in bytes
	238	* @max: the max. allowed pre-allocation size
	239	*
	240	* Do pre-allocation to all substreams of the given pcm for the
	241	* specified DMA type.
1da177e4	242	*/
bb580602	243	void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
1da177e4 LT	244	int type, void *data,
	245	size_t size, size_t max)
	246	{
877211f5	247	struct snd_pcm_substream *substream;
bb580602	248	int stream;
1da177e4 LT	249
	250	for (stream = 0; stream < 2; stream++)
	251	for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
bb580602	252	snd_pcm_lib_preallocate_pages(substream, type, data, size, max);
1da177e4	253	}
e88e8ae6 TI	254	EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
e88e8ae6 TI	255
cc6a8acd	256	#ifdef CONFIG_SND_DMA_SGBUF
1da177e4 LT	257	/**
	258	* snd_pcm_sgbuf_ops_page - get the page struct at the given offset
	259	* @substream: the pcm substream instance
	260	* @offset: the buffer offset
	261	*
1da177e4	262	* Used as the page callback of PCM ops.
eb7c06e8 YB	263	*
eb7c06e8 YB	264	* Return: The page struct at the given buffer offset. %NULL on failure.
1da177e4	265	*/
877211f5	266	struct page snd_pcm_sgbuf_ops_page(struct snd_pcm_substream substream, unsigned long offset)
1da177e4 LT	267	{
	268	struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
	269
	270	unsigned int idx = offset >> PAGE_SHIFT;
	271	if (idx >= (unsigned int)sgbuf->pages)
	272	return NULL;
	273	return sgbuf->page_table[idx];
	274	}
e88e8ae6	275	EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
cc6a8acd	276	#endif /* CONFIG_SND_DMA_SGBUF */
51e9f2e6	277
1da177e4 LT	278	/**
	279	* snd_pcm_lib_malloc_pages - allocate the DMA buffer
	280	* @substream: the substream to allocate the DMA buffer to
	281	* @size: the requested buffer size in bytes
	282	*
	283	* Allocates the DMA buffer on the BUS type given earlier to
	284	* snd_pcm_lib_preallocate_xxx_pages().
	285	*
eb7c06e8	286	* Return: 1 if the buffer is changed, 0 if not changed, or a negative
1da177e4 LT	287	* code on failure.
1da177e4 LT	288	*/
877211f5	289	int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
1da177e4	290	{
877211f5	291	struct snd_pcm_runtime *runtime;
1da177e4 LT	292	struct snd_dma_buffer *dmab = NULL;
1da177e4 LT	293
7eaa943c TI	294	if (PCM_RUNTIME_CHECK(substream))
	295	return -EINVAL;
	296	if (snd_BUG_ON(substream->dma_buffer.dev.type ==
	297	SNDRV_DMA_TYPE_UNKNOWN))
	298	return -EINVAL;
1da177e4	299	runtime = substream->runtime;
1da177e4 LT	300
	301	if (runtime->dma_buffer_p) {
	302	/* perphaps, we might free the large DMA memory region
	303	to save some space here, but the actual solution
	304	costs us less time */
	305	if (runtime->dma_buffer_p->bytes >= size) {
	306	runtime->dma_bytes = size;
	307	return 0; /* ok, do not change */
	308	}
	309	snd_pcm_lib_free_pages(substream);
	310	}
877211f5 TI	311	if (substream->dma_buffer.area != NULL &&
877211f5 TI	312	substream->dma_buffer.bytes >= size) {
1da177e4 LT	313	dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
1da177e4 LT	314	} else {
ca2c0966	315	dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
1da177e4 LT	316	if (! dmab)
	317	return -ENOMEM;
	318	dmab->dev = substream->dma_buffer.dev;
	319	if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
	320	substream->dma_buffer.dev.dev,
	321	size, dmab) < 0) {
	322	kfree(dmab);
	323	return -ENOMEM;
	324	}
	325	}
	326	snd_pcm_set_runtime_buffer(substream, dmab);
	327	runtime->dma_bytes = size;
	328	return 1; /* area was changed */
	329	}
e88e8ae6 TI	330	EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
e88e8ae6 TI	331
1da177e4 LT	332	/**
	333	* snd_pcm_lib_free_pages - release the allocated DMA buffer.
	334	* @substream: the substream to release the DMA buffer
	335	*
	336	* Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
	337	*
eb7c06e8	338	* Return: Zero if successful, or a negative error code on failure.
1da177e4	339	*/
877211f5	340	int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
1da177e4	341	{
877211f5	342	struct snd_pcm_runtime *runtime;
1da177e4	343
7eaa943c TI	344	if (PCM_RUNTIME_CHECK(substream))
7eaa943c TI	345	return -EINVAL;
1da177e4	346	runtime = substream->runtime;
1da177e4 LT	347	if (runtime->dma_area == NULL)
	348	return 0;
	349	if (runtime->dma_buffer_p != &substream->dma_buffer) {
	350	/* it's a newly allocated buffer. release it now. */
	351	snd_dma_free_pages(runtime->dma_buffer_p);
	352	kfree(runtime->dma_buffer_p);
	353	}
	354	snd_pcm_set_runtime_buffer(substream, NULL);
	355	return 0;
	356	}
e88e8ae6	357	EXPORT_SYMBOL(snd_pcm_lib_free_pages);
681b84e1 CL	358
	359	int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
	360	size_t size, gfp_t gfp_flags)
	361	{
	362	struct snd_pcm_runtime *runtime;
	363
	364	if (PCM_RUNTIME_CHECK(substream))
	365	return -EINVAL;
	366	runtime = substream->runtime;
	367	if (runtime->dma_area) {
	368	if (runtime->dma_bytes >= size)
	369	return 0; /* already large enough */
	370	vfree(runtime->dma_area);
	371	}
	372	runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
	373	if (!runtime->dma_area)
	374	return -ENOMEM;
	375	runtime->dma_bytes = size;
	376	return 1;
	377	}
	378	EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
	379
	380	/**
	381	* snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
	382	* @substream: the substream with a buffer allocated by
	383	* snd_pcm_lib_alloc_vmalloc_buffer()
eb7c06e8 YB	384	*
eb7c06e8 YB	385	* Return: Zero if successful, or a negative error code on failure.
681b84e1 CL	386	*/
	387	int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
	388	{
	389	struct snd_pcm_runtime *runtime;
	390
	391	if (PCM_RUNTIME_CHECK(substream))
	392	return -EINVAL;
	393	runtime = substream->runtime;
	394	vfree(runtime->dma_area);
	395	runtime->dma_area = NULL;
	396	return 0;
	397	}
	398	EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
	399
	400	/**
	401	* snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
	402	* @substream: the substream with a buffer allocated by
	403	* snd_pcm_lib_alloc_vmalloc_buffer()
	404	* @offset: offset in the buffer
	405	*
	406	* This function is to be used as the page callback in the PCM ops.
eb7c06e8 YB	407	*
eb7c06e8 YB	408	* Return: The page struct, or %NULL on failure.
681b84e1 CL	409	*/
	410	struct page snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream substream,
	411	unsigned long offset)
	412	{
	413	return vmalloc_to_page(substream->runtime->dma_area + offset);
	414	}
	415	EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);