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Commit 681b84e1 authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Takashi Iwai
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sound: pcm: add vmalloc buffer helper functions 



There are now five copies of the code to allocate a PCM buffer using
vmalloc().  Add a sixth in the core so that the others can be removed.

Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 14d44e2c

include/sound/pcm.h

+38 −0
Original line number Diff line number Diff line
@@ -905,6 +905,44 @@ int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm, 
int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size);

int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream);



int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,

				      size_t size, gfp_t gfp_flags);

int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream);

struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,

					  unsigned long offset);

#if 0 /* for kernel-doc */

/**

 * snd_pcm_lib_alloc_vmalloc_buffer - allocate virtual DMA buffer

 * @substream: the substream to allocate the buffer to

 * @size: the requested buffer size, in bytes

 *

 * Allocates the PCM substream buffer using vmalloc(), i.e., the memory is

 * contiguous in kernel virtual space, but not in physical memory.  Use this

 * if the buffer is accessed by kernel code but not by device DMA.

 *

 * Returns 1 if the buffer was changed, 0 if not changed, or a negative error

 * code.

 */

static int snd_pcm_lib_alloc_vmalloc_buffer

			(struct snd_pcm_substream *substream, size_t size);

/**

 * snd_pcm_lib_alloc_vmalloc_32_buffer - allocate 32-bit-addressable buffer

 * @substream: the substream to allocate the buffer to

 * @size: the requested buffer size, in bytes

 *

 * This function works like snd_pcm_lib_alloc_vmalloc_buffer(), but uses

 * vmalloc_32(), i.e., the pages are allocated from 32-bit-addressable memory.

 */

static int snd_pcm_lib_alloc_vmalloc_32_buffer

			(struct snd_pcm_substream *substream, size_t size);

#endif

#define snd_pcm_lib_alloc_vmalloc_buffer(subs, size) \

	_snd_pcm_lib_alloc_vmalloc_buffer \

			(subs, size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO)

#define snd_pcm_lib_alloc_vmalloc_32_buffer(subs, size) \

	_snd_pcm_lib_alloc_vmalloc_buffer \

			(subs, size, GFP_KERNEL | GFP_DMA32 | __GFP_ZERO)



#ifdef CONFIG_SND_DMA_SGBUF

/*

 * SG-buffer handling

sound/core/pcm_memory.c

+54 −0
Original line number Diff line number Diff line
@@ -434,3 +434,57 @@ int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream) 
}



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()

 */

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.

 */

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);