ALSA: memalloc: Make SG-buffer helper usable for continuous buffer, too

We have a few helper functions for making the access to the buffer
address easier on SG-buffer.  Those are specific to the buffer that is
allocated with SG-buffer type, and it makes hard to use both SG and
non-SG buffers in the same code.

This patch adds a few simple checks and lets the helpers to deal with
both SG- and continuous buffers gracefully.  It's a preliminary step
for the upcoming patch that mimics the buffer type on the fly.

Link: https://lore.kernel.org/r/20200615160045.2703-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2020-06-15 18:00:44 +02:00
parent 28e60dbb83
commit 2a1f3368bf
2 changed files with 11 additions and 1 deletions

View File

@ -94,7 +94,11 @@ static inline dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab,
size_t offset)
{
struct snd_sg_buf *sgbuf = dmab->private_data;
dma_addr_t addr = sgbuf->table[offset >> PAGE_SHIFT].addr;
dma_addr_t addr;
if (!sgbuf)
return dmab->addr + offset;
addr = sgbuf->table[offset >> PAGE_SHIFT].addr;
addr &= ~((dma_addr_t)PAGE_SIZE - 1);
return addr + offset % PAGE_SIZE;
}
@ -106,6 +110,9 @@ static inline void *snd_sgbuf_get_ptr(struct snd_dma_buffer *dmab,
size_t offset)
{
struct snd_sg_buf *sgbuf = dmab->private_data;
if (!sgbuf)
return dmab->area + offset;
return sgbuf->table[offset >> PAGE_SHIFT].buf + offset % PAGE_SIZE;
}

View File

@ -142,6 +142,9 @@ unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
struct snd_sg_buf *sg = dmab->private_data;
unsigned int start, end, pg;
if (!sg)
return size;
start = ofs >> PAGE_SHIFT;
end = (ofs + size - 1) >> PAGE_SHIFT;
/* check page continuity */