[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>
#include "pcm_local.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;

static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
module_param(max_alloc_per_card, ulong, 0644);
MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");

static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
{
	card->total_pcm_alloc_bytes += bytes;
}

static void update_allocated_size(struct snd_card *card, ssize_t bytes)
{
	guard(mutex)(&card->memory_mutex);
	__update_allocated_size(card, bytes);
}

static void decrease_allocated_size(struct snd_card *card, size_t bytes)
{
	guard(mutex)(&card->memory_mutex);
	WARN_ON(card->total_pcm_alloc_bytes < bytes);
	__update_allocated_size(card, -(ssize_t)bytes);
}

static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
			  int str, size_t size, struct snd_dma_buffer *dmab)
{
	enum dma_data_direction dir;
	int err;

	/* check and reserve the requested size */
	scoped_guard(mutex, &card->memory_mutex) {
		if (max_alloc_per_card &&
		    card->total_pcm_alloc_bytes + size > max_alloc_per_card)
			return -ENOMEM;
		__update_allocated_size(card, size);
	}

	if (str == SNDRV_PCM_STREAM_PLAYBACK)
		dir = DMA_TO_DEVICE;
	else
		dir = DMA_FROM_DEVICE;
	err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
	if (!err) {
		/* the actual allocation size might be bigger than requested,
		 * and we need to correct the account
		 */
		if (dmab->bytes != size)
			update_allocated_size(card, dmab->bytes - size);
	} else {
		/* take back on allocation failure */
		decrease_allocated_size(card, size);
	}
	return err;
}

static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
{
	if (!dmab->area)
		return;
	decrease_allocated_size(card, dmab->bytes);
	snd_dma_free_pages(dmab);
	dmab->area = NULL;
}

/*
 * 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, bool no_fallback)
{
	struct snd_dma_buffer *dmab = &substream->dma_buffer;
	struct snd_card *card = substream->pcm->card;
	size_t orig_size = size;
	int err;

	do {
		err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
				     substream->stream, size, dmab);
		if (err != -ENOMEM)
			return err;
		if (no_fallback)
			break;
		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 -ENOMEM;
}

/**
 * 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)
{
	do_free_pages(substream->pcm->card, &substream->dma_buffer);
}

/**
 * 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_each_pcm_substream(pcm, stream, substream)
		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;
	struct snd_card *card = substream->pcm->card;
	char line[64], str[64];
	size_t size;
	struct snd_dma_buffer new_dmab;

	guard(mutex)(&substream->pcm->open_mutex);
	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 (do_alloc_pages(card,
					   substream->dma_buffer.dev.type,
					   substream->dma_buffer.dev.dev,
					   substream->stream,
					   size, &new_dmab) < 0) {
				buffer->error = -ENOMEM;
				pr_debug("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, size);
				return;
			}
			substream->buffer_bytes_max = size;
		} else {
			substream->buffer_bytes_max = UINT_MAX;
		}
		if (substream->dma_buffer.area)
			do_free_pages(card, &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 */
static inline void preallocate_info_init(struct snd_pcm_substream *substream)
{
}
#endif /* CONFIG_SND_VERBOSE_PROCFS */

/*
 * pre-allocate the buffer and create a proc file for the substream
 */
static int preallocate_pages(struct snd_pcm_substream *substream,
			      int type, struct device *data,
			      size_t size, size_t max, bool managed)
{
	int err;

	if (snd_BUG_ON(substream->dma_buffer.dev.type))
		return -EINVAL;

	substream->dma_buffer.dev.type = type;
	substream->dma_buffer.dev.dev = data;

	if (size > 0) {
		if (!max) {
			/* no fallback, only also inform -ENOMEM */
			err = preallocate_pcm_pages(substream, size, true);
			if (err < 0)
				return err;
		} else if (preallocate_dma &&
			   substream->number < maximum_substreams) {
			err = preallocate_pcm_pages(substream, size, false);
			if (err < 0 && err != -ENOMEM)
				return err;
		}
	}

	if (substream->dma_buffer.bytes > 0)
		substream->buffer_bytes_max = substream->dma_buffer.bytes;
	substream->dma_max = max;
	if (max > 0)
		preallocate_info_init(substream);
	if (managed)
		substream->managed_buffer_alloc = 1;
	return 0;
}

static int preallocate_pages_for_all(struct snd_pcm *pcm, int type,
				      void *data, size_t size, size_t max,
				      bool managed)
{
	struct snd_pcm_substream *substream;
	int stream, err;

	for_each_pcm_substream(pcm, stream, substream) {
		err = preallocate_pages(substream, type, data, size, max, managed);
		if (err < 0)
			return err;
	}
	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.
 */
void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
				  int type, struct device *data,
				  size_t size, size_t max)
{
	preallocate_pages(substream, type, data, size, max, false);
}
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)
{
	preallocate_pages_for_all(pcm, type, data, size, max, false);
}
EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);

/**
 * snd_pcm_set_managed_buffer - set up buffer management for a substream
 * @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, and set the managed
 * buffer allocation mode to the given substream.
 * In this mode, PCM core will allocate a buffer automatically before PCM
 * hw_params ops call, and release the buffer after PCM hw_free ops call
 * as well, so that the driver doesn't need to invoke the allocation and
 * the release explicitly in its callback.
 * When a buffer is actually allocated before the PCM hw_params call, it
 * turns on the runtime buffer_changed flag for drivers changing their h/w
 * parameters accordingly.
 *
 * When @size is non-zero and @max is zero, this tries to allocate for only
 * the exact buffer size without fallback, and may return -ENOMEM.
 * Otherwise, the function tries to allocate smaller chunks if the allocation
 * fails.  This is the behavior of snd_pcm_set_fixed_buffer().
 *
 * When both @size and @max are zero, the function only sets up the buffer
 * for later dynamic allocations. It's used typically for buffers with
 * SNDRV_DMA_TYPE_VMALLOC type.
 *
 * Upon successful buffer allocation and setup, the function returns 0.
 *
 * Return: zero if successful, or a negative error code
 */
int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
				struct device *data, size_t size, size_t max)
{
	return preallocate_pages(substream, type, data, size, max, true);
}
EXPORT_SYMBOL(snd_pcm_set_managed_buffer);

/**
 * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
 *	for 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 and size, and set the managed_buffer_alloc flag to each substream.
 *
 * Return: zero if successful, or a negative error code
 */
int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
				   struct device *data,
				   size_t size, size_t max)
{
	return preallocate_pages_for_all(pcm, type, data, size, max, true);
}
EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);

/**
 * 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_card *card;
	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;
	card = substream->pcm->card;

	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 {
		/* dma_max=0 means the fixed size preallocation */
		if (substream->dma_buffer.area && !substream->dma_max)
			return -ENOMEM;
		dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
		if (! dmab)
			return -ENOMEM;
		dmab->dev = substream->dma_buffer.dev;
		if (do_alloc_pages(card,
				   substream->dma_buffer.dev.type,
				   substream->dma_buffer.dev.dev,
				   substream->stream,
				   size, dmab) < 0) {
			kfree(dmab);
			pr_debug("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, size);
			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) {
		struct snd_card *card = substream->pcm->card;

		/* it's a newly allocated buffer.  release it now. */
		do_free_pages(card, 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);
	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>
0821fd77	18	#include "pcm_local.h"
1da177e4 LT	19
	20	static int preallocate_dma = 1;
	21	module_param(preallocate_dma, int, 0444);
	22	MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
	23
	24	static int maximum_substreams = 4;
	25	module_param(maximum_substreams, int, 0444);
	26	MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
	27
	28	static const size_t snd_minimum_buffer = 16384;
	29
d4cfb30f TI	30	static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
	31	module_param(max_alloc_per_card, ulong, 0644);
	32	MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
	33
bd55842e TI	34	static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
	35	{
	36	card->total_pcm_alloc_bytes += bytes;
	37	}
	38
	39	static void update_allocated_size(struct snd_card *card, ssize_t bytes)
	40	{
dd0da75b	41	guard(mutex)(&card->memory_mutex);
bd55842e	42	__update_allocated_size(card, bytes);
bd55842e TI	43	}
	44
	45	static void decrease_allocated_size(struct snd_card *card, size_t bytes)
	46	{
dd0da75b	47	guard(mutex)(&card->memory_mutex);
bd55842e TI	48	WARN_ON(card->total_pcm_alloc_bytes < bytes);
bd55842e TI	49	__update_allocated_size(card, -(ssize_t)bytes);
bd55842e TI	50	}
bd55842e TI	51
d4cfb30f	52	static int do_alloc_pages(struct snd_card card, int type, struct device dev,
a25684a9	53	int str, size_t size, struct snd_dma_buffer *dmab)
d4cfb30f	54	{
a25684a9	55	enum dma_data_direction dir;
d4cfb30f TI	56	int err;
d4cfb30f TI	57
bd55842e	58	/* check and reserve the requested size */
dd0da75b TI	59	scoped_guard(mutex, &card->memory_mutex) {
	60	if (max_alloc_per_card &&
	61	card->total_pcm_alloc_bytes + size > max_alloc_per_card)
	62	return -ENOMEM;
	63	__update_allocated_size(card, size);
bd55842e	64	}
3ad796cb	65
a25684a9 TI	66	if (str == SNDRV_PCM_STREAM_PLAYBACK)
	67	dir = DMA_TO_DEVICE;
	68	else
	69	dir = DMA_FROM_DEVICE;
	70	err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
d4cfb30f	71	if (!err) {
bd55842e TI	72	/* the actual allocation size might be bigger than requested,
	73	* and we need to correct the account
	74	*/
	75	if (dmab->bytes != size)
	76	update_allocated_size(card, dmab->bytes - size);
	77	} else {
	78	/* take back on allocation failure */
	79	decrease_allocated_size(card, size);
d4cfb30f TI	80	}
	81	return err;
	82	}
	83
	84	static void do_free_pages(struct snd_card card, struct snd_dma_buffer dmab)
	85	{
	86	if (!dmab->area)
	87	return;
bd55842e	88	decrease_allocated_size(card, dmab->bytes);
d4cfb30f TI	89	snd_dma_free_pages(dmab);
	90	dmab->area = NULL;
	91	}
1da177e4 LT	92
	93	/*
	94	* try to allocate as the large pages as possible.
	95	* stores the resultant memory size in *res_size.
	96	*
	97	* the minimum size is snd_minimum_buffer. it should be power of 2.
	98	*/
ac9245a5 TI	99	static int preallocate_pcm_pages(struct snd_pcm_substream *substream,
ac9245a5 TI	100	size_t size, bool no_fallback)
1da177e4 LT	101	{
1da177e4 LT	102	struct snd_dma_buffer *dmab = &substream->dma_buffer;
d4cfb30f	103	struct snd_card *card = substream->pcm->card;
6ab08ced	104	size_t orig_size = size;
1da177e4 LT	105	int err;
1da177e4 LT	106
1da177e4	107	do {
d4cfb30f	108	err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
a25684a9	109	substream->stream, size, dmab);
d4cfb30f TI	110	if (err != -ENOMEM)
d4cfb30f TI	111	return err;
ac9245a5 TI	112	if (no_fallback)
ac9245a5 TI	113	break;
1da177e4 LT	114	size >>= 1;
	115	} while (size >= snd_minimum_buffer);
	116	dmab->bytes = 0; /* tell error */
6ab08ced TI	117	pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
	118	substream->pcm->card->number, substream->pcm->device,
	119	substream->stream ? 'c' : 'p', substream->number,
	120	substream->pcm->name, orig_size);
ac9245a5	121	return -ENOMEM;
1da177e4 LT	122	}
1da177e4 LT	123
1da177e4 LT	124	/**
	125	* snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
	126	* @substream: the pcm substream instance
	127	*
	128	* Releases the pre-allocated buffer of the given substream.
1da177e4	129	*/
bb580602	130	void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
1da177e4	131	{
f2283366	132	do_free_pages(substream->pcm->card, &substream->dma_buffer);
1da177e4 LT	133	}
	134
	135	/**
	136	* snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
	137	* @pcm: the pcm instance
	138	*
	139	* Releases all the pre-allocated buffers on the given pcm.
1da177e4	140	*/
bb580602	141	void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
1da177e4	142	{
877211f5	143	struct snd_pcm_substream *substream;
1da177e4 LT	144	int stream;
1da177e4 LT	145
8d19b4e0 TI	146	for_each_pcm_substream(pcm, stream, substream)
8d19b4e0 TI	147	snd_pcm_lib_preallocate_free(substream);
1da177e4	148	}
e88e8ae6 TI	149	EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
e88e8ae6 TI	150
b7d90a35	151	#ifdef CONFIG_SND_VERBOSE_PROCFS
1da177e4 LT	152	/*
	153	* read callback for prealloc proc file
	154	*
	155	* prints the current allocated size in kB.
	156	*/
877211f5 TI	157	static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
877211f5 TI	158	struct snd_info_buffer *buffer)
1da177e4	159	{
877211f5	160	struct snd_pcm_substream *substream = entry->private_data;
1da177e4 LT	161	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
	162	}
	163
c7132aeb JK	164	/*
	165	* read callback for prealloc_max proc file
	166	*
	167	* prints the maximum allowed size in kB.
	168	*/
	169	static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
	170	struct snd_info_buffer *buffer)
	171	{
	172	struct snd_pcm_substream *substream = entry->private_data;
	173	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
	174	}
	175
1da177e4 LT	176	/*
	177	* write callback for prealloc proc file
	178	*
	179	* accepts the preallocation size in kB.
	180	*/
877211f5 TI	181	static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
877211f5 TI	182	struct snd_info_buffer *buffer)
1da177e4	183	{
877211f5	184	struct snd_pcm_substream *substream = entry->private_data;
d4cfb30f	185	struct snd_card *card = substream->pcm->card;
1da177e4 LT	186	char line[64], str[64];
	187	size_t size;
	188	struct snd_dma_buffer new_dmab;
	189
dd0da75b	190	guard(mutex)(&substream->pcm->open_mutex);
1da177e4 LT	191	if (substream->runtime) {
1da177e4 LT	192	buffer->error = -EBUSY;
dd0da75b	193	return;
1da177e4 LT	194	}
	195	if (!snd_info_get_line(buffer, line, sizeof(line))) {
	196	snd_info_get_str(str, line, sizeof(str));
	197	size = simple_strtoul(str, NULL, 10) * 1024;
	198	if ((size != 0 && size < 8192) \|\| size > substream->dma_max) {
	199	buffer->error = -EINVAL;
dd0da75b	200	return;
1da177e4 LT	201	}
1da177e4 LT	202	if (substream->dma_buffer.bytes == size)
dd0da75b	203	return;
1da177e4 LT	204	memset(&new_dmab, 0, sizeof(new_dmab));
	205	new_dmab.dev = substream->dma_buffer.dev;
	206	if (size > 0) {
d4cfb30f TI	207	if (do_alloc_pages(card,
	208	substream->dma_buffer.dev.type,
	209	substream->dma_buffer.dev.dev,
a25684a9	210	substream->stream,
d4cfb30f	211	size, &new_dmab) < 0) {
1da177e4	212	buffer->error = -ENOMEM;
dc85fc9d AS	213	pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
	214	substream->pcm->card->number, substream->pcm->device,
	215	substream->stream ? 'c' : 'p', substream->number,
	216	substream->pcm->name, size);
dd0da75b	217	return;
1da177e4 LT	218	}
	219	substream->buffer_bytes_max = size;
	220	} else {
	221	substream->buffer_bytes_max = UINT_MAX;
	222	}
	223	if (substream->dma_buffer.area)
d4cfb30f	224	do_free_pages(card, &substream->dma_buffer);
1da177e4 LT	225	substream->dma_buffer = new_dmab;
	226	} else {
	227	buffer->error = -EINVAL;
	228	}
	229	}
	230
e28563cc	231	static inline void preallocate_info_init(struct snd_pcm_substream *substream)
1da177e4	232	{
877211f5	233	struct snd_info_entry *entry;
1da177e4	234
a8d14981 TI	235	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
	236	substream->proc_root);
	237	if (entry) {
	238	snd_info_set_text_ops(entry, substream,
	239	snd_pcm_lib_preallocate_proc_read);
1da177e4	240	entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
6a73cf46	241	entry->mode \|= 0200;
c7132aeb	242	}
a8d14981 TI	243	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
	244	substream->proc_root);
	245	if (entry)
	246	snd_info_set_text_ops(entry, substream,
	247	snd_pcm_lib_preallocate_max_proc_read);
e28563cc TI	248	}
e28563cc TI	249
b7d90a35	250	#else /* !CONFIG_SND_VERBOSE_PROCFS */
940ba1f5 AB	251	static inline void preallocate_info_init(struct snd_pcm_substream *substream)
	252	{
	253	}
b7d90a35	254	#endif /* CONFIG_SND_VERBOSE_PROCFS */
e28563cc TI	255
	256	/*
	257	* pre-allocate the buffer and create a proc file for the substream
	258	*/
ac9245a5	259	static int preallocate_pages(struct snd_pcm_substream *substream,
0dba808e TI	260	int type, struct device *data,
0dba808e TI	261	size_t size, size_t max, bool managed)
e28563cc	262	{
ac9245a5 TI	263	int err;
ac9245a5 TI	264
0dba808e	265	if (snd_BUG_ON(substream->dma_buffer.dev.type))
ac9245a5	266	return -EINVAL;
0dba808e TI	267
	268	substream->dma_buffer.dev.type = type;
	269	substream->dma_buffer.dev.dev = data;
e28563cc	270
ac9245a5 TI	271	if (size > 0) {
	272	if (!max) {
	273	/* no fallback, only also inform -ENOMEM */
	274	err = preallocate_pcm_pages(substream, size, true);
	275	if (err < 0)
	276	return err;
	277	} else if (preallocate_dma &&
	278	substream->number < maximum_substreams) {
	279	err = preallocate_pcm_pages(substream, size, false);
	280	if (err < 0 && err != -ENOMEM)
	281	return err;
	282	}
	283	}
e28563cc TI	284
	285	if (substream->dma_buffer.bytes > 0)
	286	substream->buffer_bytes_max = substream->dma_buffer.bytes;
	287	substream->dma_max = max;
d3978991 TI	288	if (max > 0)
d3978991 TI	289	preallocate_info_init(substream);
0dba808e TI	290	if (managed)
0dba808e TI	291	substream->managed_buffer_alloc = 1;
ac9245a5	292	return 0;
1da177e4 LT	293	}
1da177e4 LT	294
ac9245a5	295	static int preallocate_pages_for_all(struct snd_pcm *pcm, int type,
0dba808e TI	296	void *data, size_t size, size_t max,
	297	bool managed)
	298	{
	299	struct snd_pcm_substream *substream;
ac9245a5	300	int stream, err;
0dba808e	301
ac9245a5 TI	302	for_each_pcm_substream(pcm, stream, substream) {
	303	err = preallocate_pages(substream, type, data, size, max, managed);
	304	if (err < 0)
	305	return err;
	306	}
	307	return 0;
0dba808e	308	}
1da177e4 LT	309
	310	/**
	311	* snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
	312	* @substream: the pcm substream instance
	313	* @type: DMA type (SNDRV_DMA_TYPE_*)
25985edc	314	* @data: DMA type dependent data
1da177e4 LT	315	* @size: the requested pre-allocation size in bytes
	316	* @max: the max. allowed pre-allocation size
	317	*
	318	* Do pre-allocation for the given DMA buffer type.
1da177e4	319	*/
bb580602	320	void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
1da177e4 LT	321	int type, struct device *data,
	322	size_t size, size_t max)
	323	{
0dba808e	324	preallocate_pages(substream, type, data, size, max, false);
1da177e4	325	}
e88e8ae6 TI	326	EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
e88e8ae6 TI	327
1da177e4	328	/**
25985edc	329	* snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
df8db936	330	* @pcm: the pcm instance
1da177e4	331	* @type: DMA type (SNDRV_DMA_TYPE_*)
25985edc	332	* @data: DMA type dependent data
1da177e4 LT	333	* @size: the requested pre-allocation size in bytes
	334	* @max: the max. allowed pre-allocation size
	335	*
	336	* Do pre-allocation to all substreams of the given pcm for the
	337	* specified DMA type.
1da177e4	338	*/
bb580602	339	void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
1da177e4 LT	340	int type, void *data,
	341	size_t size, size_t max)
	342	{
0dba808e	343	preallocate_pages_for_all(pcm, type, data, size, max, false);
1da177e4	344	}
e88e8ae6 TI	345	EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
e88e8ae6 TI	346
0dba808e TI	347	/**
	348	* snd_pcm_set_managed_buffer - set up buffer management for a substream
	349	* @substream: the pcm substream instance
	350	* @type: DMA type (SNDRV_DMA_TYPE_*)
	351	* @data: DMA type dependent data
	352	* @size: the requested pre-allocation size in bytes
	353	* @max: the max. allowed pre-allocation size
	354	*
	355	* Do pre-allocation for the given DMA buffer type, and set the managed
	356	* buffer allocation mode to the given substream.
	357	* In this mode, PCM core will allocate a buffer automatically before PCM
	358	* hw_params ops call, and release the buffer after PCM hw_free ops call
	359	* as well, so that the driver doesn't need to invoke the allocation and
	360	* the release explicitly in its callback.
	361	* When a buffer is actually allocated before the PCM hw_params call, it
	362	* turns on the runtime buffer_changed flag for drivers changing their h/w
	363	* parameters accordingly.
ac9245a5 TI	364	*
	365	* When @size is non-zero and @max is zero, this tries to allocate for only
	366	* the exact buffer size without fallback, and may return -ENOMEM.
	367	* Otherwise, the function tries to allocate smaller chunks if the allocation
	368	* fails. This is the behavior of snd_pcm_set_fixed_buffer().
	369	*
	370	* When both @size and @max are zero, the function only sets up the buffer
	371	* for later dynamic allocations. It's used typically for buffers with
	372	* SNDRV_DMA_TYPE_VMALLOC type.
	373	*
	374	* Upon successful buffer allocation and setup, the function returns 0.
4e2b7067 TI	375	*
4e2b7067 TI	376	* Return: zero if successful, or a negative error code
0dba808e	377	*/
ac9245a5	378	int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
0dba808e TI	379	struct device *data, size_t size, size_t max)
0dba808e TI	380	{
ac9245a5	381	return preallocate_pages(substream, type, data, size, max, true);
0dba808e TI	382	}
	383	EXPORT_SYMBOL(snd_pcm_set_managed_buffer);
	384
	385	/**
	386	* snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
	387	* for all substreams
	388	* @pcm: the pcm instance
	389	* @type: DMA type (SNDRV_DMA_TYPE_*)
	390	* @data: DMA type dependent data
	391	* @size: the requested pre-allocation size in bytes
	392	* @max: the max. allowed pre-allocation size
	393	*
	394	* Do pre-allocation to all substreams of the given pcm for the specified DMA
	395	* type and size, and set the managed_buffer_alloc flag to each substream.
4e2b7067 TI	396	*
4e2b7067 TI	397	* Return: zero if successful, or a negative error code
0dba808e	398	*/
ac9245a5 TI	399	int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
	400	struct device *data,
	401	size_t size, size_t max)
0dba808e	402	{
ac9245a5	403	return preallocate_pages_for_all(pcm, type, data, size, max, true);
0dba808e TI	404	}
	405	EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);
	406
1da177e4 LT	407	/**
	408	* snd_pcm_lib_malloc_pages - allocate the DMA buffer
	409	* @substream: the substream to allocate the DMA buffer to
	410	* @size: the requested buffer size in bytes
	411	*
	412	* Allocates the DMA buffer on the BUS type given earlier to
	413	* snd_pcm_lib_preallocate_xxx_pages().
	414	*
eb7c06e8	415	* Return: 1 if the buffer is changed, 0 if not changed, or a negative
1da177e4 LT	416	* code on failure.
1da177e4 LT	417	*/
877211f5	418	int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
1da177e4	419	{
b658cbab	420	struct snd_card *card;
877211f5	421	struct snd_pcm_runtime *runtime;
1da177e4 LT	422	struct snd_dma_buffer *dmab = NULL;
1da177e4 LT	423
7eaa943c TI	424	if (PCM_RUNTIME_CHECK(substream))
	425	return -EINVAL;
	426	if (snd_BUG_ON(substream->dma_buffer.dev.type ==
	427	SNDRV_DMA_TYPE_UNKNOWN))
	428	return -EINVAL;
1da177e4	429	runtime = substream->runtime;
b658cbab	430	card = substream->pcm->card;
1da177e4 LT	431
	432	if (runtime->dma_buffer_p) {
	433	/* perphaps, we might free the large DMA memory region
	434	to save some space here, but the actual solution
	435	costs us less time */
	436	if (runtime->dma_buffer_p->bytes >= size) {
	437	runtime->dma_bytes = size;
	438	return 0; /* ok, do not change */
	439	}
	440	snd_pcm_lib_free_pages(substream);
	441	}
877211f5 TI	442	if (substream->dma_buffer.area != NULL &&
877211f5 TI	443	substream->dma_buffer.bytes >= size) {
1da177e4 LT	444	dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
1da177e4 LT	445	} else {
ac9245a5 TI	446	/* dma_max=0 means the fixed size preallocation */
	447	if (substream->dma_buffer.area && !substream->dma_max)
	448	return -ENOMEM;
ca2c0966	449	dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
1da177e4 LT	450	if (! dmab)
	451	return -ENOMEM;
	452	dmab->dev = substream->dma_buffer.dev;
d4cfb30f TI	453	if (do_alloc_pages(card,
	454	substream->dma_buffer.dev.type,
	455	substream->dma_buffer.dev.dev,
a25684a9	456	substream->stream,
d4cfb30f	457	size, dmab) < 0) {
1da177e4	458	kfree(dmab);
dc85fc9d AS	459	pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
	460	substream->pcm->card->number, substream->pcm->device,
	461	substream->stream ? 'c' : 'p', substream->number,
	462	substream->pcm->name, size);
1da177e4 LT	463	return -ENOMEM;
	464	}
	465	}
	466	snd_pcm_set_runtime_buffer(substream, dmab);
	467	runtime->dma_bytes = size;
	468	return 1; /* area was changed */
	469	}
e88e8ae6 TI	470	EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
e88e8ae6 TI	471
1da177e4 LT	472	/**
	473	* snd_pcm_lib_free_pages - release the allocated DMA buffer.
	474	* @substream: the substream to release the DMA buffer
	475	*
	476	* Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
	477	*
eb7c06e8	478	* Return: Zero if successful, or a negative error code on failure.
1da177e4	479	*/
877211f5	480	int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
1da177e4	481	{
877211f5	482	struct snd_pcm_runtime *runtime;
1da177e4	483
7eaa943c TI	484	if (PCM_RUNTIME_CHECK(substream))
7eaa943c TI	485	return -EINVAL;
1da177e4	486	runtime = substream->runtime;
1da177e4 LT	487	if (runtime->dma_area == NULL)
	488	return 0;
	489	if (runtime->dma_buffer_p != &substream->dma_buffer) {
011b559b CIK	490	struct snd_card *card = substream->pcm->card;
011b559b CIK	491
1da177e4	492	/* it's a newly allocated buffer. release it now. */
d4cfb30f	493	do_free_pages(card, runtime->dma_buffer_p);
1da177e4 LT	494	kfree(runtime->dma_buffer_p);
	495	}
	496	snd_pcm_set_runtime_buffer(substream, NULL);
	497	return 0;
	498	}
e88e8ae6	499	EXPORT_SYMBOL(snd_pcm_lib_free_pages);
681b84e1 CL	500
	501	int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
	502	size_t size, gfp_t gfp_flags)
	503	{
	504	struct snd_pcm_runtime *runtime;
	505
	506	if (PCM_RUNTIME_CHECK(substream))
	507	return -EINVAL;
	508	runtime = substream->runtime;
	509	if (runtime->dma_area) {
	510	if (runtime->dma_bytes >= size)
	511	return 0; /* already large enough */
	512	vfree(runtime->dma_area);
	513	}
88dca4ca	514	runtime->dma_area = __vmalloc(size, gfp_flags);
681b84e1 CL	515	if (!runtime->dma_area)
	516	return -ENOMEM;
	517	runtime->dma_bytes = size;
	518	return 1;
	519	}
	520	EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
	521
	522	/**
	523	* snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
	524	* @substream: the substream with a buffer allocated by
	525	* snd_pcm_lib_alloc_vmalloc_buffer()
eb7c06e8 YB	526	*
eb7c06e8 YB	527	* Return: Zero if successful, or a negative error code on failure.
681b84e1 CL	528	*/
	529	int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
	530	{
	531	struct snd_pcm_runtime *runtime;
	532
	533	if (PCM_RUNTIME_CHECK(substream))
	534	return -EINVAL;
	535	runtime = substream->runtime;
	536	vfree(runtime->dma_area);
	537	runtime->dma_area = NULL;
	538	return 0;
	539	}
	540	EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
	541
	542	/**
	543	* snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
	544	* @substream: the substream with a buffer allocated by
	545	* snd_pcm_lib_alloc_vmalloc_buffer()
	546	* @offset: offset in the buffer
	547	*
	548	* This function is to be used as the page callback in the PCM ops.
eb7c06e8 YB	549	*
eb7c06e8 YB	550	* Return: The page struct, or %NULL on failure.
681b84e1 CL	551	*/
	552	struct page snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream substream,
	553	unsigned long offset)
	554	{
	555	return vmalloc_to_page(substream->runtime->dma_area + offset);
	556	}
	557	EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);