Commit 9f600630 authored by Takashi Iwai's avatar Takashi Iwai

ALSA: pcm: More unification of PCM transfer codes

This patch proceeds more abstraction of PCM read/write loop codes.

For both interleaved and non-interleaved transfers, the same copy or
silence transfer code (which is defined as pcm_transfer_f) is used
now.  This became possible since we switched to byte size to copy_*
and fill_silence ops argument instead of frames.

And, for both read and write, we can use the same copy function (which
is defined as pcm_copy_f), just depending on whether interleaved or
non-interleaved mode.

The transfer function is determined at the beginning of the loop,
depending on whether the driver gives the specific copy ops or it's
the standard read/write.

Another bonus by this change is that we now guarantee the silencing
behavior when NULL buffer is passed to write helpers.  It'll simplify
some codes later.
Reviewed-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent c48f12ee
......@@ -1993,78 +1993,101 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
return err;
}
typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
void *data, unsigned int off,
snd_pcm_uframes_t size);
typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes);
static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
unsigned int hwoff,
void *data, unsigned int off,
snd_pcm_uframes_t frames)
typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);
/* calculate the target DMA-buffer position to be written/read */
static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
int channel, unsigned long hwoff)
{
return runtime->dma_area + hwoff +
channel * (runtime->dma_bytes / runtime->channels);
}
/* default copy_user ops for write */
static int default_write_copy_user(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void __user *buf, unsigned long bytes)
{
if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
buf, bytes))
return -EFAULT;
return 0;
}
/* fill silence instead of copy data; called as a transfer helper
* from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
* a NULL buffer is passed
*/
static int fill_silence(struct snd_pcm_substream *substream, int channel,
unsigned long hwoff, void *buf, unsigned long bytes)
{
struct snd_pcm_runtime *runtime = substream->runtime;
int err;
char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
if (substream->ops->copy_user) {
if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
return 0;
if (substream->ops->fill_silence)
return substream->ops->fill_silence(substream, channel,
hwoff, bytes);
snd_pcm_format_set_silence(runtime->format,
get_dma_ptr(runtime, channel, hwoff),
bytes_to_samples(runtime, bytes));
return 0;
}
/* call transfer function with the converted pointers and sizes;
* for interleaved mode, it's one shot for all samples
*/
static int interleaved_copy(struct snd_pcm_substream *substream,
snd_pcm_uframes_t hwoff, void *data,
snd_pcm_uframes_t off,
snd_pcm_uframes_t frames,
pcm_transfer_f transfer)
{
struct snd_pcm_runtime *runtime = substream->runtime;
/* convert to bytes */
hwoff = frames_to_bytes(runtime, hwoff);
off = frames_to_bytes(runtime, off);
frames = frames_to_bytes(runtime, frames);
err = substream->ops->copy_user(substream, 0, hwoff, buf, frames);
if (err < 0)
return err;
} else {
char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
return -EFAULT;
}
return 0;
return transfer(substream, 0, hwoff, data + off, frames);
}
static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
unsigned int hwoff,
void *data, unsigned int off,
snd_pcm_uframes_t frames)
/* call transfer function with the converted pointers and sizes for each
* non-interleaved channel; when buffer is NULL, silencing instead of copying
*/
static int noninterleaved_copy(struct snd_pcm_substream *substream,
snd_pcm_uframes_t hwoff, void *data,
snd_pcm_uframes_t off,
snd_pcm_uframes_t frames,
pcm_transfer_f transfer)
{
struct snd_pcm_runtime *runtime = substream->runtime;
int err;
void __user **bufs = (void __user **)data;
int channels = runtime->channels;
char __user *buf;
int c;
void **bufs = data;
int c, err;
if (substream->ops->copy_user) {
hwoff = samples_to_bytes(runtime, hwoff);
/* convert to bytes; note that it's not frames_to_bytes() here.
* in non-interleaved mode, we copy for each channel, thus
* each copy is n_samples bytes x channels = whole frames.
*/
off = samples_to_bytes(runtime, off);
frames = samples_to_bytes(runtime, frames);
hwoff = samples_to_bytes(runtime, hwoff);
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,
if (!data || !*bufs)
err = fill_silence(substream, c, hwoff, NULL, frames);
else
err = transfer(substream, c, hwoff, *bufs + off,
frames);
}
if (err < 0)
return err;
}
} else {
/* default transfer behaviour */
size_t dma_csize = runtime->dma_bytes / channels;
for (c = 0; c < channels; ++c, ++bufs) {
char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
if (*bufs == NULL) {
snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
} else {
char __user *buf = *bufs + samples_to_bytes(runtime, off);
if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
return -EFAULT;
}
}
}
return 0;
}
......@@ -2106,24 +2129,33 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream,
snd_pcm_uframes_t xfer = 0;
snd_pcm_uframes_t offset = 0;
snd_pcm_uframes_t avail;
transfer_f transfer;
pcm_copy_f writer;
pcm_transfer_f transfer;
bool nonblock;
int err;
err = pcm_sanity_check(substream);
if (err < 0)
return err;
runtime = substream->runtime;
if (interleaved) {
if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
runtime->channels > 1)
return -EINVAL;
transfer = snd_pcm_lib_write_transfer;
writer = interleaved_copy;
} else {
if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
return -EINVAL;
transfer = snd_pcm_lib_writev_transfer;
writer = noninterleaved_copy;
}
if (!data) {
transfer = fill_silence;
} else {
if (substream->ops->copy_user)
transfer = (pcm_transfer_f)substream->ops->copy_user;
else
transfer = default_write_copy_user;
}
if (size == 0)
......@@ -2166,7 +2198,8 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream,
appl_ptr = runtime->control->appl_ptr;
appl_ofs = appl_ptr % runtime->buffer_size;
snd_pcm_stream_unlock_irq(substream);
err = transfer(substream, appl_ofs, data, offset, frames);
err = writer(substream, appl_ofs, data, offset, frames,
transfer);
snd_pcm_stream_lock_irq(substream);
if (err < 0)
goto _end_unlock;
......@@ -2200,65 +2233,15 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream,
}
EXPORT_SYMBOL(__snd_pcm_lib_write);
static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
unsigned int hwoff,
void *data, unsigned int off,
snd_pcm_uframes_t frames)
{
struct snd_pcm_runtime *runtime = substream->runtime;
int err;
char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
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 {
char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
return -EFAULT;
}
return 0;
}
static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
unsigned int hwoff,
void *data, unsigned int off,
snd_pcm_uframes_t frames)
/* default copy_user ops for read */
static int default_read_copy_user(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes)
{
struct snd_pcm_runtime *runtime = substream->runtime;
int err;
void __user **bufs = (void __user **)data;
int channels = runtime->channels;
char __user *buf;
char *hwbuf;
int c;
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 {
snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
for (c = 0; c < channels; ++c, ++bufs) {
if (*bufs == NULL)
continue;
hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
buf = *bufs + samples_to_bytes(runtime, off);
if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
if (copy_to_user((void __user *)buf,
get_dma_ptr(substream->runtime, channel, hwoff),
bytes))
return -EFAULT;
}
}
return 0;
}
......@@ -2270,26 +2253,34 @@ snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream,
snd_pcm_uframes_t xfer = 0;
snd_pcm_uframes_t offset = 0;
snd_pcm_uframes_t avail;
transfer_f transfer;
pcm_copy_f reader;
pcm_transfer_f transfer;
bool nonblock;
int err;
err = pcm_sanity_check(substream);
if (err < 0)
return err;
runtime = substream->runtime;
if (!data)
return -EINVAL;
if (interleaved) {
if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
runtime->channels > 1)
return -EINVAL;
transfer = snd_pcm_lib_read_transfer;
reader = interleaved_copy;
} else {
if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
return -EINVAL;
transfer = snd_pcm_lib_readv_transfer;
reader = noninterleaved_copy;
}
if (substream->ops->copy_user)
transfer = (pcm_transfer_f)substream->ops->copy_user;
else
transfer = default_read_copy_user;
if (size == 0)
return 0;
......@@ -2343,7 +2334,8 @@ snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream,
appl_ptr = runtime->control->appl_ptr;
appl_ofs = appl_ptr % runtime->buffer_size;
snd_pcm_stream_unlock_irq(substream);
err = transfer(substream, appl_ofs, data, offset, frames);
err = reader(substream, appl_ofs, data, offset, frames,
transfer);
snd_pcm_stream_lock_irq(substream);
if (err < 0)
goto _end_unlock;
......
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