/**
*
* vq_ring_enable_interrupt
*
*/
static int vq_ring_enable_interrupt(struct virtqueue *vq, uint16_t ndesc)
{
/*
* Enable interrupts, making sure we get the latest index of
* what's already been consumed.
*/
if (vq->vq_flags & VIRTQUEUE_FLAG_EVENT_IDX) {
vring_used_event(&vq->vq_ring) = vq->vq_used_cons_idx + ndesc;
} else {
vq->vq_ring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
}
env_mb();
/*
* Enough items may have already been consumed to meet our threshold
* since we last checked. Let our caller know so it processes the new
* entries.
*/
if (virtqueue_nused(vq) > ndesc) {
return (1);
}
return (0);
}
int
virtqueue_postpone_intr(struct virtqueue *vq)
{
uint16_t ndesc;
/*
* Postpone until at least half of the available descriptors
* have been consumed.
*
* XXX Adaptive factor? (Linux uses 3/4)
*/
ndesc = (uint16_t)(vq->vq_ring.avail->idx - vq->vq_used_cons_idx) / 2;
if (vq->vq_flags & VIRTQUEUE_FLAG_EVENT_IDX)
vring_used_event(&vq->vq_ring) = vq->vq_used_cons_idx + ndesc;
else
vq->vq_ring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
cpu_mfence();
/*
* Enough items may have already been consumed to meet our
* threshold since we last checked. Let our caller know so
* it processes the new entries.
*/
if (virtqueue_nused(vq) > ndesc)
return (1);
return (0);
}
/**
* virtqueue_dump Dumps important virtqueue fields , use for debugging purposes
*
* @param vq - Pointer to VirtIO queue control block
*/
void virtqueue_dump(struct virtqueue *vq)
{
if (vq == VQ_NULL)
return;
env_print("VQ: %s - size=%d; free=%d; used=%d; queued=%d; "
"desc_head_idx=%d; avail.idx=%d; used_cons_idx=%d; "
"used.idx=%d; avail.flags=0x%x; used.flags=0x%x\r\n",
vq->vq_name, vq->vq_nentries, vq->vq_free_cnt,
virtqueue_nused(vq), vq->vq_queued_cnt, vq->vq_desc_head_idx,
vq->vq_ring.avail->idx, vq->vq_used_cons_idx,
vq->vq_ring.used->idx, vq->vq_ring.avail->flags,
vq->vq_ring.used->flags);
}
