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virtio-snd: implement queue function lookup table #120

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Merged
jserv merged 1 commit into from
Jan 3, 2026
+42 −23
Merged

virtio-snd: implement queue function lookup table #120

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65 changes: 42 additions & 23 deletions virtio-snd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -331,9 +331,7 @@ static int virtio_snd_stream_cb(const void *input,
const PaStreamCallbackTimeInfo *time_info,
PaStreamCallbackFlags status_flags,
void *user_data);
static void virtio_queue_notify_handler(virtio_snd_state_t *vsnd,
int index, /* virtq index */
vsnd_virtq_cb cb);
static void virtio_queue_notify_handler(virtio_snd_state_t *vsnd, int index);
static void __virtio_snd_frame_enqueue(void *payload,
uint32_t n,
uint32_t stream_id);
Expand All @@ -347,11 +345,8 @@ typedef struct {
*/
static uint32_t flush_stream_id = 0;

#define VSND_GEN_TX_QUEUE_HANDLER(NAME_SUFFIX, WRITE) \
static int virtio_snd_tx_desc_##NAME_SUFFIX##_handler( \
virtio_snd_state_t *vsnd, const virtio_snd_queue_t *queue, \
uint32_t desc_idx, uint32_t *plen) \
{ \
#define VSND_TX_QUEUE_BODY(WRITE) \
do { \
/* A PCM I/O message uses at least 3 virtqueue descriptors to \
* represent a PCM data of a period size. \
* The first part contains one descriptor as follows: \
Expand Down Expand Up @@ -455,10 +450,23 @@ static uint32_t flush_stream_id = 0;
\
finally: \
return 0; \
}
} while (0)

VSND_GEN_TX_QUEUE_HANDLER(normal, 1);
VSND_GEN_TX_QUEUE_HANDLER(flush, 0);
static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
const virtio_snd_queue_t *queue,
uint32_t desc_idx,
uint32_t *plen)
{
VSND_TX_QUEUE_BODY(1);
}

static int virtio_snd_io_desc_flush_handler(virtio_snd_state_t *vsnd,
const virtio_snd_queue_t *queue,
uint32_t desc_idx,
uint32_t *plen)
{
VSND_TX_QUEUE_BODY(0);
}

static void virtio_snd_set_fail(virtio_snd_state_t *vsnd)
{
Expand Down Expand Up @@ -723,6 +731,7 @@ static void virtio_snd_read_pcm_stop(const virtio_snd_pcm_hdr_t *query,
*plen = 0;
}

#define VSND_FLUSH_QUEUE 0x4
static void virtio_snd_read_pcm_release(const virtio_snd_pcm_hdr_t *query,
uint32_t *plen,
virtio_snd_state_t *vsnd)
Expand Down Expand Up @@ -770,7 +779,7 @@ static void virtio_snd_read_pcm_release(const virtio_snd_pcm_hdr_t *query,
* - The device MUST NOT complete the control request while there
* are pending I/O messages for the specified stream ID.
*/
virtio_queue_notify_handler(vsnd, 2, virtio_snd_tx_desc_flush_handler);
virtio_queue_notify_handler(vsnd, VSND_FLUSH_QUEUE | 0x2);

*plen = 0;
}
Expand Down Expand Up @@ -912,6 +921,20 @@ static int virtio_snd_ctrl_desc_handler(virtio_snd_state_t *vsnd,
return 0;
}

/* virtq device operation lookup table */
/* The entry of flush queue operation (whether it is needed or not
* for each type of queue) starts from 0x04.
* So we can set bit with 0x04 when we need to flush queue. */
static vsnd_virtq_cb __virtio_snd_queue_op_tbl[8] = {
virtio_snd_ctrl_desc_handler, /* control queue */
NULL, /* event queue */
virtio_snd_tx_desc_handler, /* TX queue */
NULL, /* RX queue */
NULL, /* no need to flush control queue, so trigger a failed null check */
NULL, /* no need to flush event queue, so trigger a failed null check */
virtio_snd_io_desc_flush_handler, /* flush TX queue */
NULL, /* flush RX queue */
};

static void __virtio_snd_frame_enqueue(void *payload,
uint32_t n,
Expand Down Expand Up @@ -949,16 +972,10 @@ static void __virtio_snd_frame_enqueue(void *payload,
pthread_mutex_unlock(&props->lock.lock);
}

static void virtio_queue_notify_handler(
virtio_snd_state_t *vsnd,
int index,
int (*handler)(virtio_snd_state_t *,
const virtio_snd_queue_t *,
uint32_t,
uint32_t *))
static void virtio_queue_notify_handler(virtio_snd_state_t *vsnd, int index)
{
uint32_t *ram = vsnd->ram;
virtio_snd_queue_t *queue = &vsnd->queues[index];
virtio_snd_queue_t *queue = &vsnd->queues[index & 0x03];
if (vsnd->Status & VIRTIO_STATUS__DEVICE_NEEDS_RESET)
return;

Expand Down Expand Up @@ -992,6 +1009,9 @@ static void virtio_queue_notify_handler(
* descriptor list.
*/
uint32_t len = 0;
vsnd_virtq_cb handler = __virtio_snd_queue_op_tbl[index & 0x07];
if (!handler)
return virtio_snd_set_fail(vsnd);
int result = handler(vsnd, queue, buffer_idx, &len);
if (result != 0)
return virtio_snd_set_fail(vsnd);
Expand Down Expand Up @@ -1026,7 +1046,7 @@ static void *func(void *args)
pthread_cond_wait(&virtio_snd_tx_cond, &virtio_snd_mutex);

tx_ev_notify--;
virtio_queue_notify_handler(vsnd, 2, virtio_snd_tx_desc_normal_handler);
virtio_queue_notify_handler(vsnd, 2);

pthread_mutex_unlock(&virtio_snd_mutex);
}
Expand Down Expand Up @@ -1140,8 +1160,7 @@ static bool virtio_snd_reg_write(virtio_snd_state_t *vsnd,
if (value < ARRAY_SIZE(vsnd->queues)) {
switch (value) {
case VSND_QUEUE_CTRL:
virtio_queue_notify_handler(vsnd, value,
virtio_snd_ctrl_desc_handler);
virtio_queue_notify_handler(vsnd, value);
break;
case VSND_QUEUE_TX:
tx_ev_notify++;
Expand Down
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