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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: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2021-06-09 18:25:51 +02:00
parent a202bd1ad8
commit 30b7ba6972
1 changed files with 17 additions and 0 deletions
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17
sound/core/memalloc.c
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@ -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,