When investigating current implementation for data copy between
kernel/user spaces, helper functions includes much conditional processing.
This brings lack of lucidity. Furthermore, this is not good in a point
of hit ratio of i-cache.
This commit adds some helper functions for each cases to transfer PCM
frames; to read and write, for interleaved and non-interleaved frame
alignments. These helper functions also performs to transfer silent PCM
frames when source buffer is NULL.
Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
---
sound/core/pcm_lib.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 121 insertions(+), 8 deletions(-)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index f06d9f4f9574..38baa91fd0f6 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -42,6 +42,100 @@
#define trace_hw_ptr_error(substream, reason)
#endif
+static int writei_from_space1(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 __user *buf = (char __user *)data;
+ char *dst = runtime->dma_area + frames_to_bytes(runtime, hwoff);
+
+ if (buf == NULL) {
+ snd_pcm_format_set_silence(runtime->format, dst,
+ count * runtime->channels);
+ } else {
+ if (copy_from_user(dst, buf, frames_to_bytes(runtime, count)))
+ return -EFAULT;
+ }
+
+ 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)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ char __user **bufs = (char __user **)data;
+ char __user *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);
+ if (copy_from_user(dst, buf, samples_to_bytes(runtime, count)))
+ return -EFAULT;
+ }
+
+ 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)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ char __user *buf = (char __user *)data;
+ char *src = runtime->dma_area + frames_to_bytes(runtime, hwoff);
+
+ if (buf == NULL)
+ return -EINVAL;
+ buf += frames_to_bytes(runtime, off);
+
+ if (copy_to_user(buf, src, frames_to_bytes(runtime, count)))
+ return -EFAULT;
+
+ 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)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ char __user **bufs = (char __user **)data;
+ char __user *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);
+ if (copy_to_user(buf, src, samples_to_bytes(runtime, count)))
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
static int writei_silence(struct snd_pcm_substream *substream,
unsigned int hwoff, unsigned long data,
unsigned int off, snd_pcm_uframes_t count)
@@ -156,10 +250,17 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream,
return;
if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
- runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
- copy_frames = writei_silence;
- else
- copy_frames = writen_silence;
+ runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
+ if (substream->ops->silence)
+ copy_frames = writei_silence;
+ else
+ copy_frames = writei_from_space1;
+ } else {
+ if (substream->ops->silence)
+ copy_frames = writen_silence;
+ else
+ copy_frames = writen_from_space1;
+ }
ofs = runtime->silence_start % runtime->buffer_size;
while (frames > 0) {
@@ -2178,7 +2279,10 @@ snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream,
runtime->channels > 1)
return -EINVAL;
- copy_frames = snd_pcm_lib_write_transfer;
+ if (substream->ops->copy)
+ copy_frames = snd_pcm_lib_write_transfer;
+ else
+ copy_frames = writei_from_space1;
return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
copy_frames);
@@ -2243,7 +2347,10 @@ snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
return -EINVAL;
- copy_frames = snd_pcm_lib_writev_transfer;
+ if (substream->ops->copy)
+ copy_frames = snd_pcm_lib_writev_transfer;
+ else
+ copy_frames = writen_from_space1;
return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
nonblock, copy_frames);
@@ -2395,7 +2502,10 @@ snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream,
if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
return -EINVAL;
- copy_frames = snd_pcm_lib_read_transfer;
+ if (substream->ops->copy)
+ copy_frames = snd_pcm_lib_read_transfer;
+ else
+ copy_frames = readi_to_space1;
return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock,
copy_frames);
@@ -2458,7 +2568,10 @@ snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
return -EINVAL;
- copy_frames = snd_pcm_lib_readv_transfer;
+ if (substream->ops->copy)
+ copy_frames = snd_pcm_lib_readv_transfer;
+ else
+ copy_frames = readn_to_space1;
return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames,
nonblock, copy_frames);
--
2.11.0
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