From 5c7264cfbb209efea04bbbd69b8b4f5f2fc5f86d Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 24 May 2017 22:36:23 +0200 Subject: [PATCH] ALSA: pcm: Unify read/write loop Both __snd_pcm_lib_read() and __snd_pcm_write() functions have almost the same code to loop over samples. For simplification, this patch unifies both as the single helper, __snd_pcm_lib_xfer(). Other than that, there should be no functional change by this patch. Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai --- include/sound/pcm.h | 13 ++- sound/core/pcm_lib.c | 184 +++++++++++-------------------------------- 2 files changed, 51 insertions(+), 146 deletions(-) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 0fac948bb053..db649083c76d 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -1072,10 +1072,7 @@ void snd_pcm_set_sync(struct snd_pcm_substream *substream); int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream, unsigned int cmd, void *arg); void snd_pcm_period_elapsed(struct snd_pcm_substream *substream); -snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream, - void *buf, bool interleaved, - snd_pcm_uframes_t frames); -snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream, +snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream, void *buf, bool interleaved, snd_pcm_uframes_t frames); @@ -1083,28 +1080,28 @@ static inline snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t frames) { - return __snd_pcm_lib_write(substream, (void *)buf, true, frames); + return __snd_pcm_lib_xfer(substream, (void *)buf, true, frames); } static inline snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t frames) { - return __snd_pcm_lib_read(substream, (void *)buf, true, frames); + return __snd_pcm_lib_xfer(substream, (void *)buf, true, frames); } static inline snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream, void __user **bufs, snd_pcm_uframes_t frames) { - return __snd_pcm_lib_write(substream, (void *)bufs, false, frames); + return __snd_pcm_lib_xfer(substream, (void *)bufs, false, frames); } static inline snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream, void __user **bufs, snd_pcm_uframes_t frames) { - return __snd_pcm_lib_read(substream, (void *)bufs, false, frames); + return __snd_pcm_lib_xfer(substream, (void *)bufs, false, frames); } int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime); diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 0c53a34201c1..af73c629a6b2 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -2008,13 +2008,13 @@ static void *get_dma_ptr(struct snd_pcm_runtime *runtime, 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) +/* default copy_user ops for write; used for both interleaved and non- modes */ +static int default_write_copy(struct snd_pcm_substream *substream, + int channel, unsigned long hwoff, + void *buf, unsigned long bytes) { if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff), - buf, bytes)) + (void __user *)buf, bytes)) return -EFAULT; return 0; } @@ -2040,6 +2040,18 @@ static int fill_silence(struct snd_pcm_substream *substream, int channel, return 0; } +/* default copy_user ops for read; used for both interleaved and non- modes */ +static int default_read_copy(struct snd_pcm_substream *substream, + int channel, unsigned long hwoff, + void *buf, unsigned long bytes) +{ + if (copy_to_user((void __user *)buf, + get_dma_ptr(substream->runtime, channel, hwoff), + bytes)) + return -EFAULT; + return 0; +} + /* call transfer function with the converted pointers and sizes; * for interleaved mode, it's one shot for all samples */ @@ -2121,9 +2133,10 @@ static int pcm_accessible_state(struct snd_pcm_runtime *runtime) } } -snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream, - void *data, bool interleaved, - snd_pcm_uframes_t size) +/* the common loop for read/write data */ +snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream, + void *data, bool interleaved, + snd_pcm_uframes_t size) { struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_uframes_t xfer = 0; @@ -2132,12 +2145,14 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream, pcm_copy_f writer; pcm_transfer_f transfer; bool nonblock; + bool is_playback; int err; err = pcm_sanity_check(substream); if (err < 0) return err; + is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; if (interleaved) { if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED && runtime->channels > 1) @@ -2150,12 +2165,16 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream, } if (!data) { - transfer = fill_silence; + if (is_playback) + transfer = fill_silence; + else + return -EINVAL; } else { if (substream->ops->copy_user) transfer = (pcm_transfer_f)substream->ops->copy_user; else - transfer = default_write_copy_user; + transfer = is_playback ? + default_write_copy : default_read_copy; } if (size == 0) @@ -2168,129 +2187,8 @@ snd_pcm_sframes_t __snd_pcm_lib_write(struct snd_pcm_substream *substream, if (err < 0) goto _end_unlock; - runtime->twake = runtime->control->avail_min ? : 1; - if (runtime->status->state == SNDRV_PCM_STATE_RUNNING) - snd_pcm_update_hw_ptr(substream); - avail = snd_pcm_playback_avail(runtime); - while (size > 0) { - snd_pcm_uframes_t frames, appl_ptr, appl_ofs; - snd_pcm_uframes_t cont; - if (!avail) { - if (nonblock) { - err = -EAGAIN; - goto _end_unlock; - } - runtime->twake = min_t(snd_pcm_uframes_t, size, - runtime->control->avail_min ? : 1); - err = wait_for_avail(substream, &avail); - if (err < 0) - goto _end_unlock; - } - frames = size > avail ? avail : size; - cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size; - if (frames > cont) - frames = cont; - if (snd_BUG_ON(!frames)) { - runtime->twake = 0; - snd_pcm_stream_unlock_irq(substream); - return -EINVAL; - } - appl_ptr = runtime->control->appl_ptr; - appl_ofs = appl_ptr % runtime->buffer_size; - snd_pcm_stream_unlock_irq(substream); - err = writer(substream, appl_ofs, data, offset, frames, - transfer); - snd_pcm_stream_lock_irq(substream); - if (err < 0) - goto _end_unlock; - err = pcm_accessible_state(runtime); - if (err < 0) - goto _end_unlock; - appl_ptr += frames; - if (appl_ptr >= runtime->boundary) - appl_ptr -= runtime->boundary; - runtime->control->appl_ptr = appl_ptr; - if (substream->ops->ack) - substream->ops->ack(substream); - - offset += frames; - size -= frames; - xfer += frames; - avail -= frames; - if (runtime->status->state == SNDRV_PCM_STATE_PREPARED && - snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) { - err = snd_pcm_start(substream); - if (err < 0) - goto _end_unlock; - } - } - _end_unlock: - runtime->twake = 0; - if (xfer > 0 && err >= 0) - snd_pcm_update_state(substream, runtime); - snd_pcm_stream_unlock_irq(substream); - return xfer > 0 ? (snd_pcm_sframes_t)xfer : err; -} -EXPORT_SYMBOL(__snd_pcm_lib_write); - -/* 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) -{ - if (copy_to_user((void __user *)buf, - get_dma_ptr(substream->runtime, channel, hwoff), - bytes)) - return -EFAULT; - return 0; -} - -snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream, - void *data, bool interleaved, - snd_pcm_uframes_t size) -{ - struct snd_pcm_runtime *runtime = substream->runtime; - snd_pcm_uframes_t xfer = 0; - snd_pcm_uframes_t offset = 0; - snd_pcm_uframes_t avail; - pcm_copy_f reader; - pcm_transfer_f transfer; - bool nonblock; - int err; - - err = pcm_sanity_check(substream); - if (err < 0) - return err; - - if (!data) - return -EINVAL; - - if (interleaved) { - if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED && - runtime->channels > 1) - return -EINVAL; - reader = interleaved_copy; - } else { - if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) - return -EINVAL; - 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; - - nonblock = !!(substream->f_flags & O_NONBLOCK); - - snd_pcm_stream_lock_irq(substream); - err = pcm_accessible_state(runtime); - if (err < 0) - goto _end_unlock; - if (runtime->status->state == SNDRV_PCM_STATE_PREPARED && + if (!is_playback && + runtime->status->state == SNDRV_PCM_STATE_PREPARED && size >= runtime->start_threshold) { err = snd_pcm_start(substream); if (err < 0) @@ -2300,13 +2198,16 @@ snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream, runtime->twake = runtime->control->avail_min ? : 1; if (runtime->status->state == SNDRV_PCM_STATE_RUNNING) snd_pcm_update_hw_ptr(substream); - avail = snd_pcm_capture_avail(runtime); + if (is_playback) + avail = snd_pcm_playback_avail(runtime); + else + avail = snd_pcm_capture_avail(runtime); while (size > 0) { snd_pcm_uframes_t frames, appl_ptr, appl_ofs; snd_pcm_uframes_t cont; if (!avail) { - if (runtime->status->state == - SNDRV_PCM_STATE_DRAINING) { + if (!is_playback && + runtime->status->state == SNDRV_PCM_STATE_DRAINING) { snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP); goto _end_unlock; } @@ -2334,7 +2235,7 @@ 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 = reader(substream, appl_ofs, data, offset, frames, + err = writer(substream, appl_ofs, data, offset, frames, transfer); snd_pcm_stream_lock_irq(substream); if (err < 0) @@ -2353,6 +2254,13 @@ snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream, size -= frames; xfer += frames; avail -= frames; + if (is_playback && + runtime->status->state == SNDRV_PCM_STATE_PREPARED && + snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) { + err = snd_pcm_start(substream); + if (err < 0) + goto _end_unlock; + } } _end_unlock: runtime->twake = 0; @@ -2361,7 +2269,7 @@ snd_pcm_sframes_t __snd_pcm_lib_read(struct snd_pcm_substream *substream, snd_pcm_stream_unlock_irq(substream); return xfer > 0 ? (snd_pcm_sframes_t)xfer : err; } -EXPORT_SYMBOL(__snd_pcm_lib_read); +EXPORT_SYMBOL(__snd_pcm_lib_xfer); /* * standard channel mapping helpers -- 2.30.2