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| author | Takashi Iwai <tiwai@suse.de> | 2017-05-10 21:02:35 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-06-02 20:37:23 +0300 |
| commit | 29d1a873de542cbb46d0641037d2601cb76be5b1 (patch) | |
| tree | 7139a700857874a25081c00dd0af4e1c85e6fb18 /include/sound | |
| parent | 7421a1671abe5bc07cc7a09f5a1be45acc403db7 (diff) | |
| download | linux-29d1a873de542cbb46d0641037d2601cb76be5b1.tar.xz | |
ALSA: pcm: Introduce copy_user, copy_kernel and fill_silence ops
For supporting the explicit in-kernel copy of PCM buffer data, and
also for further code refactoring, three new PCM ops, copy_user,
copy_kernel and fill_silence, are introduced. The old copy and
silence ops will be deprecated and removed later once when all callers
are converted.
The copy_kernel ops is the new one, and it's supposed to transfer the
PCM data from the given kernel buffer to the hardware ring-buffer (or
vice-versa depending on the stream direction), while the copy_user ops
is equivalent with the former copy ops, to transfer the data from the
user-space buffer.
The major difference of the new copy_* and fill_silence ops from the
previous ops is that the new ops take bytes instead of frames for size
and position arguments. It has two merits: first, it allows the
callback implementation often simpler (just call directly memcpy() &
co), and second, it may unify the implementations of both interleaved
and non-interleaved cases, as we'll see in the later patch.
As of this stage, copy_kernel ops isn't referred yet, but only
copy_user is used.
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'include/sound')
| -rw-r--r-- | include/sound/pcm.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 79fedf517070..86b126be49a2 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -83,6 +83,13 @@ struct snd_pcm_ops { void __user *buf, snd_pcm_uframes_t count); int (*silence)(struct snd_pcm_substream *substream, int channel, snd_pcm_uframes_t pos, snd_pcm_uframes_t count); + int (*fill_silence)(struct snd_pcm_substream *substream, int channel, + unsigned long pos, unsigned long bytes); + int (*copy_user)(struct snd_pcm_substream *substream, int channel, + unsigned long pos, void __user *buf, + unsigned long bytes); + int (*copy_kernel)(struct snd_pcm_substream *substream, int channel, + unsigned long pos, void *buf, unsigned long bytes); struct page *(*page)(struct snd_pcm_substream *substream, unsigned long offset); int (*mmap)(struct snd_pcm_substream *substream, struct vm_area_struct *vma); |