[PATCH 5/5] ALSA: core: Add continuous and vmalloc mmap ops
Takashi Iwai
tiwai at suse.de
Wed Jun 9 18:25:51 CEST 2021
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.
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
sound/core/memalloc.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index bdcb9230acf8..83b79edfa52d 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -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,
--
2.26.2
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