Commit cc6a8acd authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: Fix SG-buffer DMA with non-coherent architectures 



Using SG-buffers with dma_alloc_coherent() is often very inefficient
on non-coherent architectures because a tracking record could be
allocated in addition for each dma_alloc_coherent() call.
Instead, simply disable SG-buffers but just allocate normal continuous
buffers on non-supported (currently all but x86) architectures.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 8e4a718f

include/sound/memalloc.h

+6 −0
Original line number Diff line number Diff line
@@ -47,7 +47,11 @@ struct snd_dma_device { 
#define SNDRV_DMA_TYPE_UNKNOWN		0	/* not defined */

#define SNDRV_DMA_TYPE_CONTINUOUS	1	/* continuous no-DMA memory */

#define SNDRV_DMA_TYPE_DEV		2	/* generic device continuous */

#ifdef CONFIG_SND_DMA_SGBUF

#define SNDRV_DMA_TYPE_DEV_SG		3	/* generic device SG-buffer */

#else

#define SNDRV_DMA_TYPE_DEV_SG	SNDRV_DMA_TYPE_DEV /* no SG-buf support */

#endif



/*

 * info for buffer allocation
@@ -60,6 +64,7 @@ struct snd_dma_buffer { 
	void *private_data;	/* private for allocator; don't touch */

};



#ifdef CONFIG_SND_DMA_SGBUF

/*

 * Scatter-Gather generic device pages

 */
@@ -107,6 +112,7 @@ static inline void *snd_sgbuf_get_ptr(struct snd_sg_buf *sgbuf, size_t offset) 
{

	return sgbuf->table[offset >> PAGE_SHIFT].buf + offset % PAGE_SIZE;

}

#endif /* CONFIG_SND_DMA_SGBUF */



/* allocate/release a buffer */

int snd_dma_alloc_pages(int type, struct device *dev, size_t size,

include/sound/pcm.h

+23 −0
Original line number Diff line number Diff line
@@ -902,6 +902,7 @@ 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);



#ifdef CONFIG_SND_DMA_SGBUF

/*

 * SG-buffer handling

 */
@@ -927,6 +928,28 @@ struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, 
unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,

					  unsigned int ofs, unsigned int size);



#else /* !SND_DMA_SGBUF */

/*

 * fake using a continuous buffer

 */

static inline dma_addr_t

snd_pcm_sgbuf_get_addr(struct snd_pcm_substream *substream, unsigned int ofs)

{

	return substream->runtime->dma_addr + ofs;

}



static inline void *

snd_pcm_sgbuf_get_ptr(struct snd_pcm_substream *substream, unsigned int ofs)

{

	return substream->runtime->dma_area + ofs;

}



#define snd_pcm_sgbuf_ops_page	NULL



#define snd_pcm_sgbuf_get_chunk_size(subs, ofs, size)	(size)



#endif /* SND_DMA_SGBUF */



/* handle mmap counter - PCM mmap callback should handle this counter properly */

static inline void snd_pcm_mmap_data_open(struct vm_area_struct *area)

{

sound/core/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -206,4 +206,8 @@ config SND_PCM_XRUN_DEBUG 
config SND_VMASTER

	bool



config SND_DMA_SGBUF

	def_bool y

	depends on X86



source "sound/core/seq/Kconfig"

sound/core/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ snd-pcm-objs := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \ 
		pcm_memory.o



snd-page-alloc-y := memalloc.o

snd-page-alloc-$(CONFIG_HAS_DMA) += sgbuf.o

snd-page-alloc-$(CONFIG_SND_DMA_SGBUF) += sgbuf.o



snd-rawmidi-objs  := rawmidi.o

snd-timer-objs    := timer.o

sound/core/memalloc.c

+4 −0
Original line number Diff line number Diff line
@@ -199,6 +199,8 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size, 
	case SNDRV_DMA_TYPE_DEV:

		dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);

		break;

#endif

#ifdef CONFIG_SND_DMA_SGBUF

	case SNDRV_DMA_TYPE_DEV_SG:

		snd_malloc_sgbuf_pages(device, size, dmab, NULL);

		break;
@@ -269,6 +271,8 @@ void snd_dma_free_pages(struct snd_dma_buffer *dmab) 
	case SNDRV_DMA_TYPE_DEV:

		snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);

		break;

#endif

#ifdef CONFIG_SND_DMA_SGBUF

	case SNDRV_DMA_TYPE_DEV_SG:

		snd_free_sgbuf_pages(dmab);

		break;

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