[PATCH v2 2/4] ALSA: compress_offload: Add SNDRV_COMPRESS_TSTAMP64 ioctl

[Joris Verhaegen <verhaegen@google.com>]

The previous patch introduced the internal infrastructure for handling
64-bit timestamps. This patch exposes this capability to user-space.

Define the new ioctl command SNDRV_COMPRESS_TSTAMP64, which allows
applications to fetch the overflow-safe struct snd_compr_tstamp64.

The ioctl dispatch table is updated to handle the new command by
calling a new snd_compr_tstamp64 handler, while the legacy path is
renamed to snd_compr_tstamp32 for clarity.

Signed-off-by: Joris Verhaegen <verhaegen@google.com>
Tested-by: Joris Verhaegen <verhaegen@google.com>
Reviewed-by: David Li <dvdli@google.com>
Reviewed-by: Miller Liang <millerliang@google.com>
---
 include/uapi/sound/compress_offload.h |  2 ++
 sound/core/compress_offload.c         | 50 +++++++++++++++++++++++----
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/include/uapi/sound/compress_offload.h b/include/uapi/sound/compress_offload.h
index abd0ea3f86ee..2758d9ee3d91 100644
--- a/include/uapi/sound/compress_offload.h
+++ b/include/uapi/sound/compress_offload.h
@@ -208,6 +208,7 @@ struct snd_compr_task_status {
  * Note: only codec params can be changed runtime and stream params cant be
  * SNDRV_COMPRESS_GET_PARAMS: Query codec params
  * SNDRV_COMPRESS_TSTAMP: get the current timestamp value
+ * SNDRV_COMPRESS_TSTAMP64: get the current timestamp value in 64 bit format
  * SNDRV_COMPRESS_AVAIL: get the current buffer avail value.
  * This also queries the tstamp properties
  * SNDRV_COMPRESS_PAUSE: Pause the running stream
@@ -230,6 +231,7 @@ struct snd_compr_task_status {
 						 struct snd_compr_metadata)
 #define SNDRV_COMPRESS_TSTAMP		_IOR('C', 0x20, struct snd_compr_tstamp)
 #define SNDRV_COMPRESS_AVAIL		_IOR('C', 0x21, struct snd_compr_avail)
+#define SNDRV_COMPRESS_TSTAMP64		_IOR('C', 0x22, struct snd_compr_tstamp64)
 #define SNDRV_COMPRESS_PAUSE		_IO('C', 0x30)
 #define SNDRV_COMPRESS_RESUME		_IO('C', 0x31)
 #define SNDRV_COMPRESS_START		_IO('C', 0x32)
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index 6a8873bd62ae..40c1e69961b7 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -211,8 +211,8 @@ snd_compr_tstamp32_from_64(struct snd_compr_tstamp *tstamp32,
 	tstamp32->sampling_rate = tstamp64->sampling_rate;
 }
 
-static int snd_compr_update_tstamp(struct snd_compr_stream *stream,
-		struct snd_compr_tstamp *tstamp)
+static int snd_compr_update_tstamp32(struct snd_compr_stream *stream,
+				     struct snd_compr_tstamp *tstamp)
 {
 	u64 copied_total64;
 	struct snd_compr_tstamp64 tstamp64;
@@ -238,11 +238,30 @@ static int snd_compr_update_tstamp(struct snd_compr_stream *stream,
 	return 0;
 }
 
+static int snd_compr_update_tstamp64(struct snd_compr_stream *stream,
+				     struct snd_compr_tstamp64 *tstamp)
+{
+	int retval = snd_compr_get_tstamp64(stream, tstamp);
+
+	if (retval != 0)
+		return retval;
+
+	pr_debug("dsp consumed till %u total %llu bytes\n", tstamp->byte_offset,
+		 tstamp->copied_total);
+
+	if (stream->direction == SND_COMPRESS_PLAYBACK)
+		stream->runtime->total_bytes_transferred = tstamp->copied_total;
+	else
+		stream->runtime->total_bytes_available = tstamp->copied_total;
+
+	return 0;
+}
+
 static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
 		struct snd_compr_avail *avail)
 {
 	memset(avail, 0, sizeof(*avail));
-	snd_compr_update_tstamp(stream, &avail->tstamp);
+	snd_compr_update_tstamp32(stream, &avail->tstamp);
 	/* Still need to return avail even if tstamp can't be filled in */
 
 	if (stream->runtime->total_bytes_available == 0 &&
@@ -769,19 +788,34 @@ snd_compr_set_metadata(struct snd_compr_stream *stream, unsigned long arg)
 	return retval;
 }
 
-static inline int
-snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
+static inline int snd_compr_tstamp32(struct snd_compr_stream *stream,
+				     unsigned long arg)
 {
 	struct snd_compr_tstamp tstamp = {0};
 	int ret;
 
-	ret = snd_compr_update_tstamp(stream, &tstamp);
+	ret = snd_compr_update_tstamp32(stream, &tstamp);
 	if (ret == 0)
 		ret = copy_to_user((struct snd_compr_tstamp __user *)arg,
 			&tstamp, sizeof(tstamp)) ? -EFAULT : 0;
 	return ret;
 }
 
+static inline int snd_compr_tstamp64(struct snd_compr_stream *stream,
+				     unsigned long arg)
+{
+	struct snd_compr_tstamp64 tstamp = { 0 };
+	int ret;
+
+	ret = snd_compr_update_tstamp64(stream, &tstamp);
+	if (ret == 0)
+		ret = copy_to_user((struct snd_compr_tstamp64 __user *)arg,
+				   &tstamp, sizeof(tstamp)) ?
+			      -EFAULT :
+			      0;
+	return ret;
+}
+
 static int snd_compr_pause(struct snd_compr_stream *stream)
 {
 	int retval;
@@ -1355,7 +1389,9 @@ static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 
 	switch (_IOC_NR(cmd)) {
 	case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
-		return snd_compr_tstamp(stream, arg);
+		return snd_compr_tstamp32(stream, arg);
+	case _IOC_NR(SNDRV_COMPRESS_TSTAMP64):
+		return snd_compr_tstamp64(stream, arg);
 	case _IOC_NR(SNDRV_COMPRESS_AVAIL):
 		return snd_compr_ioctl_avail(stream, arg);
 	case _IOC_NR(SNDRV_COMPRESS_PAUSE):
-- 
2.50.0.727.gbf7dc18ff4-goog