In current design of ALSA PCM core, copying PCM frames is performed between user/kernel spaces. However, some in-kernel drivers wish to copy between kernel/kernel spaces. I call such drivers as 'proxy' drivers. This commit adds a infrastructure to assist the proxy drivers. New helper functions are added to copy innner kernel space. A new member, 'client_space', is added into runtime of PCM substream to utilize these helper functions. Usually, this member has 1 to represent target PCM frames on user space. When this member is 0, typical copying functions are executed between kernel/kernel space. Reference: http://mailman.alsa-project.org/pipermail/alsa-devel/2017-May/120542.html Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx> --- include/sound/pcm.h | 1 + sound/core/pcm_lib.c | 147 +++++++++++++++++++++++++++++++++++++++++++----- sound/core/pcm_native.c | 8 +++ 3 files changed, 141 insertions(+), 15 deletions(-) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index cf97e478b664..ffd21fe0b284 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -387,6 +387,7 @@ struct snd_pcm_runtime { /* -- mmap -- */ struct snd_pcm_mmap_status *status; struct snd_pcm_mmap_control *control; + int client_space; /* Where the client puts PCM frames. Usually, 1 means user space. */ /* -- locking / scheduling -- */ snd_pcm_uframes_t twake; /* do transfer (!poll) wakeup if non-zero */ diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 7b8d35823de6..7700be3bb0c8 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -42,6 +42,22 @@ #define trace_hw_ptr_error(substream, reason) #endif +static int writei_from_space0(struct snd_pcm_substream *substream, + unsigned int hwoff, unsigned long data, + unsigned int off, snd_pcm_uframes_t count) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + char *buf = (char *)data; + char *dst = runtime->dma_area + frames_to_bytes(runtime, hwoff); + + if (buf != NULL) + snd_pcm_format_set_silence(runtime->format, dst, count); + else + memcpy(dst, buf, frames_to_bytes(runtime, count)); + + return 0; +} + static int writei_from_space1(struct snd_pcm_substream *substream, unsigned int hwoff, unsigned long data, unsigned int off, snd_pcm_uframes_t count) @@ -61,6 +77,36 @@ static int writei_from_space1(struct snd_pcm_substream *substream, return 0; } +static int writen_from_space0(struct snd_pcm_substream *substream, + unsigned int hwoff, unsigned long data, + unsigned int off, snd_pcm_uframes_t count) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + char **bufs = (char **)data; + char *buf; + char *dst; + int channels = runtime->channels; + snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels; + int c; + + for (c = 0; c < channels; ++c) { + dst = runtime->dma_area + (c * dma_csize) + + samples_to_bytes(runtime, hwoff); + + if (bufs == NULL || bufs[c] == NULL) { + snd_pcm_format_set_silence(runtime->format, dst, count); + continue; + } + buf = bufs[c] + samples_to_bytes(runtime, off); + + dst = runtime->dma_area + (c * dma_csize) + + samples_to_bytes(runtime, hwoff); + memcpy(dst, buf, samples_to_bytes(runtime, count)); + } + + return 0; +} + static int writen_from_space1(struct snd_pcm_substream *substream, unsigned int hwoff, unsigned long data, unsigned int off, snd_pcm_uframes_t count) @@ -92,6 +138,19 @@ static int writen_from_space1(struct snd_pcm_substream *substream, return 0; } +static int readi_to_space0(struct snd_pcm_substream *substream, + unsigned int hwoff, unsigned long data, + unsigned int off, snd_pcm_uframes_t count) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + char *buf = (char *)data + frames_to_bytes(runtime, off); + char *src = runtime->dma_area + frames_to_bytes(runtime, hwoff); + + memcpy(buf, src, frames_to_bytes(runtime, count)); + + return 0; +} + static int readi_to_space1(struct snd_pcm_substream *substream, unsigned int hwoff, unsigned long data, unsigned int off, snd_pcm_uframes_t count) @@ -110,6 +169,31 @@ static int readi_to_space1(struct snd_pcm_substream *substream, return 0; } +static int readn_to_space0(struct snd_pcm_substream *substream, + unsigned int hwoff, unsigned long data, + unsigned int off, snd_pcm_uframes_t count) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + char **bufs = (char **)data; + char *buf; + char *src; + unsigned int channels = runtime->channels; + snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels; + int c; + + for (c = 0; c < channels; ++c) { + if (bufs == NULL || bufs[c] == NULL) + continue; + buf = bufs[c] + samples_to_bytes(runtime, off); + + src = runtime->dma_area + (c * dma_csize) + + samples_to_bytes(runtime, hwoff); + memcpy(buf, src, samples_to_bytes(runtime, count)); + } + + return 0; +} + static int readn_to_space1(struct snd_pcm_substream *substream, unsigned int hwoff, unsigned long data, unsigned int off, snd_pcm_uframes_t count) @@ -203,13 +287,21 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, return; if (substream->ops->copy_frames) { + if (runtime->client_space == 0) + return; copy_frames = substream->ops->copy_frames; } else { if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED || runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) { - copy_frames = writei_from_space1; + if (runtime->client_space == 0) + copy_frames = writei_from_space0; + else + copy_frames = writei_from_space1; } else { - copy_frames = writen_from_space1; + if (rnutime->client-space == 0) + copy_frames = writen_from_space0; + else + copy_frames = writen_from_space1; } } @@ -2211,10 +2303,16 @@ snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, runtime->channels > 1) return -EINVAL; - if (substream->ops->copy_frames) + if (substream->ops->copy_frames) { + if (runtime->client_space == 0) + return -ENXIO; copy_frames = substream->ops->copy_frames; - else - copy_frames = writei_from_space1; + } else { + if (runtime->client_space == 0) + copy_frames = writei_from_space0; + else + copy_frames = writei_from_space1; + } return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock, copy_frames); @@ -2239,10 +2337,17 @@ snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream, if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) return -EINVAL; - if (substream->ops->copy_frames) - copy_frames = substream->ops->copy_frames; - else - copy_frames = writen_from_space1; + if (substream->ops->copy_frames) { + if (runtime->client_space == 0) + return -ENXIO; + else + copy_frames = substream->ops->copy_frames; + } else { + if (runtime->client_space == 0) + copy_frames = writen_from_space0; + else + copy_frames = writen_from_space1; + } return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames, nonblock, copy_frames); @@ -2375,10 +2480,16 @@ snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED) return -EINVAL; - if (substream->ops->copy_frames) + if (substream->ops->copy_frames) { + if (runtime->client_space == 0) + return -ENXIO; copy_frames = substream->ops->copy_frames; - else - copy_frames = readi_to_space1; + } else { + if (runtime->client_space == 0) + copy_frames = readi_to_space0; + else + copy_frames = readi_to_space1; + } return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, copy_frames); @@ -2405,10 +2516,16 @@ snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream, if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) return -EINVAL; - if (substream->ops->copy_frames) + if (substream->ops->copy_frames) { + if (runtime->client_space == 0) + return -ENXIO; copy_frames = substream->ops->copy_frames; - else - copy_frames = readn_to_space1; + } else { + if (runtime->client_space == 0) + copy_frames = readn_to_space0; + else + copy_frames = readn_to_space1; + } return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, copy_frames); diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index ecde57afa45a..3428583ac0d7 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -599,6 +599,14 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream, if ((usecs = period_to_usecs(runtime)) >= 0) pm_qos_add_request(&substream->latency_pm_qos_req, PM_QOS_CPU_DMA_LATENCY, usecs); + + /* + * Usual client puts PCM frames on user space, on the other + * hand PCM proxy drivers puts on kernel space. This is a + * switch handlers for PCM frames in different spaces. + */ + runtime->client_space = 1; + return 0; _error: /* hardware might be unusable from this time, -- 2.11.0 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
