void* vring_detach_unused_buf(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
unsigned int i;
void *buf;
for (i = 0; i < vq->vring.num; i++) {
if (!vq->data[i])
continue;
buf = vq->data[i];
detach_buf(vq, i);
vq->vring.avail->idx--;
return buf;
}
return NULL;
}
static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
{
struct vring_virtqueue *vq = to_vvq(_vq);
void *ret;
struct vring_used_elem *u;
unsigned int i;
if (!more_used(vq)) {
DPrintf(4, ("No more buffers in queue: last_used_idx %d vring.used->idx %d\n",
vq->last_used_idx,
vq->vring.used->idx));
return NULL;
}
/* Only get used array entries after they have been exposed by host. */
rmb();
u = &vq->vring.used->ring[vq->last_used_idx % vq->vring.num];
i = u->id;
*len = u->len;
DPrintf(4, ("%s>>> id %d, len %d\n", __FUNCTION__, i, *len) );
if (i >= vq->vring.num) {
DPrintf(0, ("id %u out of range\n", i) );
return NULL;
}
if (!vq->data[i]) {
DPrintf(0, ("id %u is not a head!\n", i) );
return NULL;
}
/* detach_buf clears data, so grab it now. */
ret = vq->data[i];
detach_buf(vq, i);
++vq->last_used_idx;
if (!(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
*vq->vring.vring_last_used_ptr = vq->last_used_idx;
mb();
}
return ret;
}
void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
{
struct vring_virtqueue *vq = to_vvq(_vq);
u16 last_used;
unsigned i;
void *ret;
rmb();
last_used = (vq->last_used_idx & (vq->vring.num-1));
i = vq->vring.used->ring[last_used].id;
*len = vq->vring.used->ring[last_used].len;
ret = vq->data[i];
detach_buf(vq, i);
vq->last_used_idx++;
return ret;
}
void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
{
struct vring_virtqueue *vq = to_vvq(_vq);
void *ret;
unsigned int i;
START_USE(vq);
if (unlikely(vq->broken)) {
END_USE(vq);
return NULL;
}
if (!more_used(vq)) {
pr_debug("No more buffers in queue\n");
END_USE(vq);
return NULL;
}
/* Only get used array entries after they have been exposed by host. */
virtio_rmb();
i = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].id;
*len = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].len;
if (unlikely(i >= vq->vring.num)) {
BAD_RING(vq, "id %u out of range\n", i);
return NULL;
}
if (unlikely(!vq->data[i])) {
BAD_RING(vq, "id %u is not a head!\n", i);
return NULL;
}
/* detach_buf clears data, so grab it now. */
ret = vq->data[i];
detach_buf(vq, i);
vq->last_used_idx++;
END_USE(vq);
return ret;
}
void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
unsigned int i;
void *buf;
START_USE(vq);
for (i = 0; i < vq->vring.num; i++) {
if (!vq->data[i])
continue;
/* detach_buf clears data, so grab it now. */
buf = vq->data[i];
detach_buf(vq, i);
END_USE(vq);
return buf;
}
/* That should have freed everything. */
BUG_ON(vq->num_free != vq->vring.num);
END_USE(vq);
return NULL;
}