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: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai
parent
c48f12ee0a
commit
9f60063094
1 changed files with 124 additions and 132 deletions
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@ -1993,77 +1993,100 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
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return err;
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}
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typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
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void *data, unsigned int off,
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snd_pcm_uframes_t size);
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typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
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int channel, unsigned long hwoff,
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void *buf, unsigned long bytes);
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static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
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unsigned int hwoff,
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void *data, unsigned int off,
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snd_pcm_uframes_t frames)
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typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
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snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);
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/* calculate the target DMA-buffer position to be written/read */
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static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
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int channel, unsigned long hwoff)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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int err;
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char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
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if (substream->ops->copy_user) {
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hwoff = frames_to_bytes(runtime, hwoff);
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frames = frames_to_bytes(runtime, frames);
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err = substream->ops->copy_user(substream, 0, hwoff, buf, frames);
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if (err < 0)
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return err;
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} else {
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char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
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if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
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return -EFAULT;
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}
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return runtime->dma_area + hwoff +
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channel * (runtime->dma_bytes / runtime->channels);
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}
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/* default copy_user ops for write */
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static int default_write_copy_user(struct snd_pcm_substream *substream,
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int channel, unsigned long hwoff,
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void __user *buf, unsigned long bytes)
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{
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if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
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buf, bytes))
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return -EFAULT;
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return 0;
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}
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static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
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unsigned int hwoff,
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void *data, unsigned int off,
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snd_pcm_uframes_t frames)
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/* fill silence instead of copy data; called as a transfer helper
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* from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
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* a NULL buffer is passed
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*/
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static int fill_silence(struct snd_pcm_substream *substream, int channel,
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unsigned long hwoff, void *buf, unsigned long bytes)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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int err;
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void __user **bufs = (void __user **)data;
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int channels = runtime->channels;
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char __user *buf;
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int c;
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if (substream->ops->copy_user) {
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hwoff = samples_to_bytes(runtime, hwoff);
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off = samples_to_bytes(runtime, off);
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frames = samples_to_bytes(runtime, frames);
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for (c = 0; c < channels; ++c, ++bufs) {
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buf = *bufs + off;
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if (!*bufs) {
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if (snd_BUG_ON(!substream->ops->fill_silence))
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return -EINVAL;
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err = substream->ops->fill_silence(substream, c,
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hwoff,
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frames);
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} else {
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err = substream->ops->copy_user(substream, c,
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hwoff, buf,
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frames);
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}
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if (err < 0)
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return err;
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}
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} else {
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/* default transfer behaviour */
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size_t dma_csize = runtime->dma_bytes / channels;
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for (c = 0; c < channels; ++c, ++bufs) {
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char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
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if (*bufs == NULL) {
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snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
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} else {
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char __user *buf = *bufs + samples_to_bytes(runtime, off);
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if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
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return -EFAULT;
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}
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}
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if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
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return 0;
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if (substream->ops->fill_silence)
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return substream->ops->fill_silence(substream, channel,
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hwoff, bytes);
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snd_pcm_format_set_silence(runtime->format,
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get_dma_ptr(runtime, channel, hwoff),
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bytes_to_samples(runtime, bytes));
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return 0;
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}
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/* call transfer function with the converted pointers and sizes;
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* for interleaved mode, it's one shot for all samples
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*/
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static int interleaved_copy(struct snd_pcm_substream *substream,
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snd_pcm_uframes_t hwoff, void *data,
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snd_pcm_uframes_t off,
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snd_pcm_uframes_t frames,
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pcm_transfer_f transfer)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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/* convert to bytes */
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hwoff = frames_to_bytes(runtime, hwoff);
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off = frames_to_bytes(runtime, off);
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frames = frames_to_bytes(runtime, frames);
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return transfer(substream, 0, hwoff, data + off, frames);
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}
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/* call transfer function with the converted pointers and sizes for each
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* non-interleaved channel; when buffer is NULL, silencing instead of copying
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*/
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static int noninterleaved_copy(struct snd_pcm_substream *substream,
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snd_pcm_uframes_t hwoff, void *data,
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snd_pcm_uframes_t off,
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snd_pcm_uframes_t frames,
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pcm_transfer_f transfer)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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int channels = runtime->channels;
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void **bufs = data;
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int c, err;
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/* convert to bytes; note that it's not frames_to_bytes() here.
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* in non-interleaved mode, we copy for each channel, thus
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* each copy is n_samples bytes x channels = whole frames.
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*/
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off = samples_to_bytes(runtime, off);
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frames = samples_to_bytes(runtime, frames);
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hwoff = samples_to_bytes(runtime, hwoff);
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for (c = 0; c < channels; ++c, ++bufs) {
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if (!data || !*bufs)
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err = fill_silence(substream, c, hwoff, NULL, frames);
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else
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err = transfer(substream, c, hwoff, *bufs + off,
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frames);
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if (err < 0)
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return err;
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}
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return 0;
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}
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@ -2106,24 +2129,33 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream,
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snd_pcm_uframes_t xfer = 0;
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snd_pcm_uframes_t offset = 0;
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snd_pcm_uframes_t avail;
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transfer_f transfer;
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pcm_copy_f writer;
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pcm_transfer_f transfer;
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bool nonblock;
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int err;
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err = pcm_sanity_check(substream);
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if (err < 0)
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return err;
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runtime = substream->runtime;
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if (interleaved) {
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if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
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runtime->channels > 1)
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return -EINVAL;
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transfer = snd_pcm_lib_write_transfer;
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writer = interleaved_copy;
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} else {
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if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
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return -EINVAL;
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transfer = snd_pcm_lib_writev_transfer;
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writer = noninterleaved_copy;
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}
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if (!data) {
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transfer = fill_silence;
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} else {
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if (substream->ops->copy_user)
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transfer = (pcm_transfer_f)substream->ops->copy_user;
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else
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transfer = default_write_copy_user;
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}
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if (size == 0)
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@ -2166,7 +2198,8 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream,
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appl_ptr = runtime->control->appl_ptr;
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appl_ofs = appl_ptr % runtime->buffer_size;
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snd_pcm_stream_unlock_irq(substream);
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err = transfer(substream, appl_ofs, data, offset, frames);
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err = writer(substream, appl_ofs, data, offset, frames,
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transfer);
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snd_pcm_stream_lock_irq(substream);
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if (err < 0)
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goto _end_unlock;
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@ -2200,65 +2233,15 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream,
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}
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EXPORT_SYMBOL(__snd_pcm_lib_write);
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static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
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unsigned int hwoff,
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void *data, unsigned int off,
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snd_pcm_uframes_t frames)
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/* default copy_user ops for read */
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static int default_read_copy_user(struct snd_pcm_substream *substream,
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int channel, unsigned long hwoff,
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void *buf, unsigned long bytes)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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int err;
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char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
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if (substream->ops->copy_user) {
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hwoff = frames_to_bytes(runtime, hwoff);
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frames = frames_to_bytes(runtime, frames);
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err = substream->ops->copy_user(substream, 0, hwoff, buf, frames);
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if (err < 0)
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return err;
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} else {
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char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
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if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
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return -EFAULT;
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}
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return 0;
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}
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static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
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unsigned int hwoff,
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void *data, unsigned int off,
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snd_pcm_uframes_t frames)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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int err;
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void __user **bufs = (void __user **)data;
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int channels = runtime->channels;
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char __user *buf;
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char *hwbuf;
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int c;
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if (substream->ops->copy_user) {
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hwoff = samples_to_bytes(runtime, hwoff);
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off = samples_to_bytes(runtime, off);
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frames = samples_to_bytes(runtime, frames);
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for (c = 0; c < channels; ++c, ++bufs) {
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if (!*bufs)
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continue;
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err = substream->ops->copy_user(substream, c, hwoff,
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*bufs + off, frames);
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if (err < 0)
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return err;
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}
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} else {
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snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
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for (c = 0; c < channels; ++c, ++bufs) {
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if (*bufs == NULL)
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continue;
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hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
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buf = *bufs + samples_to_bytes(runtime, off);
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if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
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return -EFAULT;
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}
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}
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if (copy_to_user((void __user *)buf,
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get_dma_ptr(substream->runtime, channel, hwoff),
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bytes))
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return -EFAULT;
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return 0;
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}
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@ -2270,26 +2253,34 @@ snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream,
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snd_pcm_uframes_t xfer = 0;
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snd_pcm_uframes_t offset = 0;
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snd_pcm_uframes_t avail;
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transfer_f transfer;
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pcm_copy_f reader;
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pcm_transfer_f transfer;
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bool nonblock;
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int err;
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err = pcm_sanity_check(substream);
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if (err < 0)
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return err;
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runtime = substream->runtime;
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if (!data)
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return -EINVAL;
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if (interleaved) {
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if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
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runtime->channels > 1)
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return -EINVAL;
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transfer = snd_pcm_lib_read_transfer;
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reader = interleaved_copy;
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} else {
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if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
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return -EINVAL;
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transfer = snd_pcm_lib_readv_transfer;
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reader = noninterleaved_copy;
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}
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if (substream->ops->copy_user)
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transfer = (pcm_transfer_f)substream->ops->copy_user;
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else
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transfer = default_read_copy_user;
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if (size == 0)
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return 0;
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@ -2343,7 +2334,8 @@ snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream,
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appl_ptr = runtime->control->appl_ptr;
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appl_ofs = appl_ptr % runtime->buffer_size;
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snd_pcm_stream_unlock_irq(substream);
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err = transfer(substream, appl_ofs, data, offset, frames);
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err = reader(substream, appl_ofs, data, offset, frames,
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transfer);
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snd_pcm_stream_lock_irq(substream);
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if (err < 0)
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goto _end_unlock;
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