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ALSA: pcm: Introduce copy_user, copy_kernel and fill_silence ops

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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>
This commit is contained in:
Takashi Iwai 2017-05-10 20:02:35 +02:00
parent 7421a1671a
commit 29d1a873de
3 changed files with 84 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
include/sound/pcm.h
View File

@ -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);

89
sound/core/pcm_lib.c
View File

@ -57,6 +57,8 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t frames, ofs, transfer;
char *hwbuf;
int err;
if (runtime->silence_size < runtime->boundary) {
snd_pcm_sframes_t noise_dist, n;
@ -111,27 +113,37 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
if (substream->ops->silence) {
int err;
if (substream->ops->fill_silence) {
err = substream->ops->fill_silence(substream, 0,
frames_to_bytes(runtime, ofs),
frames_to_bytes(runtime, transfer));
snd_BUG_ON(err < 0);
} else if (substream->ops->silence) {
err = substream->ops->silence(substream, -1, ofs, transfer);
snd_BUG_ON(err < 0);
} else {
char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
}
} else {
unsigned int c;
unsigned int channels = runtime->channels;
if (substream->ops->silence) {
if (substream->ops->fill_silence) {
for (c = 0; c < channels; ++c) {
err = substream->ops->fill_silence(substream, c,
samples_to_bytes(runtime, ofs),
samples_to_bytes(runtime, transfer));
snd_BUG_ON(err < 0);
}
} else if (substream->ops->silence) {
for (c = 0; c < channels; ++c) {
int err;
err = substream->ops->silence(substream, c, ofs, transfer);
snd_BUG_ON(err < 0);
}
} else {
size_t dma_csize = runtime->dma_bytes / channels;
for (c = 0; c < channels; ++c) {
char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
}
}
@ -1997,7 +2009,13 @@ static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
struct snd_pcm_runtime *runtime = substream->runtime;
int err;
char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
if (substream->ops->copy) {
if (substream->ops->copy_user) {
hwoff = frames_to_bytes(runtime, hwoff);
frames = frames_to_bytes(runtime, frames);
err = substream->ops->copy_user(substream, 0, hwoff, buf, frames);
if (err < 0)
return err;
} else if (substream->ops->copy) {
if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
return err;
} else {
@ -2121,7 +2139,8 @@ static int pcm_sanity_check(struct snd_pcm_substream *substream)
if (PCM_RUNTIME_CHECK(substream))
return -ENXIO;
runtime = substream->runtime;
if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
if (snd_BUG_ON(!substream->ops->copy_user && !substream->ops->copy
&& !runtime->dma_area))
return -EINVAL;
if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
return -EBADFD;
@ -2158,8 +2177,30 @@ static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
int err;
void __user **bufs = (void __user **)data;
int channels = runtime->channels;
char __user *buf;
int c;
if (substream->ops->copy) {
if (substream->ops->copy_user) {
hwoff = samples_to_bytes(runtime, hwoff);
off = samples_to_bytes(runtime, off);
frames = samples_to_bytes(runtime, frames);
for (c = 0; c < channels; ++c, ++bufs) {
buf = *bufs + off;
if (!*bufs) {
if (snd_BUG_ON(!substream->ops->fill_silence))
return -EINVAL;
err = substream->ops->fill_silence(substream, c,
hwoff,
frames);
} else {
err = substream->ops->copy_user(substream, c,
hwoff, buf,
frames);
}
if (err < 0)
return err;
}
} else if (substream->ops->copy) {
if (snd_BUG_ON(!substream->ops->silence))
return -EINVAL;
for (c = 0; c < channels; ++c, ++bufs) {
@ -2167,7 +2208,7 @@ static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
return err;
} else {
char __user *buf = *bufs + samples_to_bytes(runtime, off);
buf = *bufs + samples_to_bytes(runtime, off);
if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
return err;
}
@ -2219,7 +2260,13 @@ static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
struct snd_pcm_runtime *runtime = substream->runtime;
int err;
char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
if (substream->ops->copy) {
if (substream->ops->copy_user) {
hwoff = frames_to_bytes(runtime, hwoff);
frames = frames_to_bytes(runtime, frames);
err = substream->ops->copy_user(substream, 0, hwoff, buf, frames);
if (err < 0)
return err;
} else if (substream->ops->copy) {
if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
return err;
} else {
@ -2367,10 +2414,24 @@ static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
int err;
void __user **bufs = (void __user **)data;
int channels = runtime->channels;
char __user *buf;
char *hwbuf;
int c;
if (substream->ops->copy) {
if (substream->ops->copy_user) {
hwoff = samples_to_bytes(runtime, hwoff);
off = samples_to_bytes(runtime, off);
frames = samples_to_bytes(runtime, frames);
for (c = 0; c < channels; ++c, ++bufs) {
if (!*bufs)
continue;
err = substream->ops->copy_user(substream, c, hwoff,
*bufs + off, frames);
if (err < 0)
return err;
}
} else if (substream->ops->copy) {
for (c = 0; c < channels; ++c, ++bufs) {
char __user *buf;
if (*bufs == NULL)
continue;
buf = *bufs + samples_to_bytes(runtime, off);
@ -2380,8 +2441,6 @@ static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
} else {
snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
for (c = 0; c < channels; ++c, ++bufs) {
char *hwbuf;
char __user *buf;
if (*bufs == NULL)
continue;

3
sound/soc/soc-pcm.c
View File

@ -2743,6 +2743,9 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
if (platform->driver->ops) {
rtd->ops.ack = platform->driver->ops->ack;
rtd->ops.copy_user = platform->driver->ops->copy_user;
rtd->ops.copy_kernel = platform->driver->ops->copy_kernel;
rtd->ops.fill_silence = platform->driver->ops->fill_silence;
rtd->ops.copy = platform->driver->ops->copy;
rtd->ops.silence = platform->driver->ops->silence;
rtd->ops.page = platform->driver->ops->page;