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.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/core/pcm_lib.c | 254 +++++++++++++++++++++++++--------------------------
1 file changed, 123 insertions(+), 131 deletions(-)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 1bd7244324d5..eb9cbc2d9d7b 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1991,77 +1991,100 @@ 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) {
- 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_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
- return -EFAULT;
- }
+
+ 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;
}
-
-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 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);
+ return transfer(substream, 0, hwoff, data + off, 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;
-
- 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 {
- /* 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;
- }
- }
+ void **bufs = data;
+ int c, err;
+
+ /* 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) {
+ 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;
}
return 0;
}
@@ -2104,24 +2127,33 @@ 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)
@@ -2164,7 +2196,8 @@ 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;
@@ -2198,65 +2231,15 @@ 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)))
- return -EFAULT;
- }
- }
+ if (copy_to_user((void __user *)buf,
+ get_dma_ptr(substream->runtime, channel, hwoff),
+ bytes))
+ return -EFAULT;
return 0;
}
@@ -2268,26 +2251,34 @@ 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;
@@ -2341,7 +2332,8 @@ 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;
--
2.13.0
