Commit 73325f60 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: memalloc: Support for non-coherent page allocation 

Following to the addition of non-contiguous pages, this patch adds the
new contiguous non-coherent page allocation to the standard memalloc
helper.  Like the previous non-contig type, this non-coherent type is
also directional and requires the explicit sync, too.  Hence the
driver using this type of buffer may need to set
SNDRV_PCM_INFO_EXPLICIT_SYNC flag to the PCM hardware.info as well,
unless it's set up in the managed mode.

Link: https://lore.kernel.org/r/20211017074859.24112-3-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent a25684a9

include/sound/memalloc.h

+1 −0
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ struct snd_dma_device { 
#endif

#define SNDRV_DMA_TYPE_VMALLOC		7	/* vmalloc'ed buffer */

#define SNDRV_DMA_TYPE_NONCONTIG	8	/* non-coherent SG buffer */

#define SNDRV_DMA_TYPE_NONCOHERENT	9	/* non-coherent buffer */



/*

 * info for buffer allocation

sound/core/memalloc.c

+47 −0
Original line number Diff line number Diff line
@@ -560,6 +560,52 @@ static const struct snd_malloc_ops snd_dma_noncontig_ops = { 
	.get_chunk_size = snd_dma_vmalloc_get_chunk_size,

};



/*

 * Non-coherent pages allocator

 */

static void *snd_dma_noncoherent_alloc(struct snd_dma_buffer *dmab, size_t size)

{

	dmab->dev.need_sync = dma_need_sync(dmab->dev.dev, dmab->dev.dir);

	return dma_alloc_noncoherent(dmab->dev.dev, size, &dmab->addr,

				     dmab->dev.dir, DEFAULT_GFP);

}



static void snd_dma_noncoherent_free(struct snd_dma_buffer *dmab)

{

	dma_free_noncoherent(dmab->dev.dev, dmab->bytes, dmab->area,

			     dmab->addr, dmab->dev.dir);

}



static int snd_dma_noncoherent_mmap(struct snd_dma_buffer *dmab,

				    struct vm_area_struct *area)

{

	area->vm_page_prot = vm_get_page_prot(area->vm_flags);

	return dma_mmap_pages(dmab->dev.dev, area,

			      area->vm_end - area->vm_start,

			      virt_to_page(dmab->area));

}



static void snd_dma_noncoherent_sync(struct snd_dma_buffer *dmab,

				     enum snd_dma_sync_mode mode)

{

	if (mode == SNDRV_DMA_SYNC_CPU) {

		if (dmab->dev.dir != DMA_TO_DEVICE)

			dma_sync_single_for_cpu(dmab->dev.dev, dmab->addr,

						dmab->bytes, dmab->dev.dir);

	} else {

		if (dmab->dev.dir != DMA_FROM_DEVICE)

			dma_sync_single_for_device(dmab->dev.dev, dmab->addr,

						   dmab->bytes, dmab->dev.dir);

	}

}



static const struct snd_malloc_ops snd_dma_noncoherent_ops = {

	.alloc = snd_dma_noncoherent_alloc,

	.free = snd_dma_noncoherent_free,

	.mmap = snd_dma_noncoherent_mmap,

	.sync = snd_dma_noncoherent_sync,

};



#endif /* CONFIG_HAS_DMA */



/*
@@ -572,6 +618,7 @@ static const struct snd_malloc_ops *dma_ops[] = { 
	[SNDRV_DMA_TYPE_DEV] = &snd_dma_dev_ops,

	[SNDRV_DMA_TYPE_DEV_WC] = &snd_dma_wc_ops,

	[SNDRV_DMA_TYPE_NONCONTIG] = &snd_dma_noncontig_ops,

	[SNDRV_DMA_TYPE_NONCOHERENT] = &snd_dma_noncoherent_ops,

#ifdef CONFIG_GENERIC_ALLOCATOR

	[SNDRV_DMA_TYPE_DEV_IRAM] = &snd_dma_iram_ops,

#endif /* CONFIG_GENERIC_ALLOCATOR */