Commit 30b7ba69 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: core: Add continuous and vmalloc mmap ops 

The mmap of continuous pages and vmalloc'ed pages are relatively
easily done in a shot with the existing helper functions.
Implement the mmap ops for those types, so that the mmap works without
relying on the page fault handling.

Link: https://lore.kernel.org/r/20210609162551.7842-6-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent a202bd1a

sound/core/memalloc.c

+17 −0
Original line number Diff line number Diff line
@@ -211,9 +211,19 @@ static void snd_dma_continuous_free(struct snd_dma_buffer *dmab) 
	free_pages_exact(dmab->area, dmab->bytes);

}



static int snd_dma_continuous_mmap(struct snd_dma_buffer *dmab,

				   struct vm_area_struct *area)

{

	return remap_pfn_range(area, area->vm_start,

			       dmab->addr >> PAGE_SHIFT,

			       area->vm_end - area->vm_start,

			       area->vm_page_prot);

}



static const struct snd_malloc_ops snd_dma_continuous_ops = {

	.alloc = snd_dma_continuous_alloc,

	.free = snd_dma_continuous_free,

	.mmap = snd_dma_continuous_mmap,

};



/*
@@ -232,6 +242,12 @@ static void snd_dma_vmalloc_free(struct snd_dma_buffer *dmab) 
	vfree(dmab->area);

}



static int snd_dma_vmalloc_mmap(struct snd_dma_buffer *dmab,

				struct vm_area_struct *area)

{

	return remap_vmalloc_range(area, dmab->area, 0);

}



static dma_addr_t snd_dma_vmalloc_get_addr(struct snd_dma_buffer *dmab,

					   size_t offset)

{
@@ -259,6 +275,7 @@ snd_dma_vmalloc_get_chunk_size(struct snd_dma_buffer *dmab, 
static const struct snd_malloc_ops snd_dma_vmalloc_ops = {

	.alloc = snd_dma_vmalloc_alloc,

	.free = snd_dma_vmalloc_free,

	.mmap = snd_dma_vmalloc_mmap,

	.get_addr = snd_dma_vmalloc_get_addr,

	.get_page = snd_dma_vmalloc_get_page,

	.get_chunk_size = snd_dma_vmalloc_get_chunk_size,