static void
vtrnd_harvest(struct vtrnd_softc *sc)
{
struct sglist_seg segs[1];
struct sglist sg;
struct virtqueue *vq;
uint32_t value;
int error;
vq = sc->vtrnd_vq;
sglist_init(&sg, 1, segs);
error = sglist_append(&sg, &value, sizeof(value));
KASSERT(error == 0 && sg.sg_nseg == 1,
("%s: error %d adding buffer to sglist", __func__, error));
if (!virtqueue_empty(vq))
return;
if (virtqueue_enqueue(vq, &value, &sg, 0, 1) != 0)
return;
/*
* Poll for the response, but the command is likely already
* done when we return from the notify.
*/
virtqueue_notify(vq);
virtqueue_poll(vq, NULL);
random_harvest_queue(&value, sizeof(value), sizeof(value) * NBBY / 2,
RANDOM_PURE_VIRTIO);
}
/*
* Generate a DSGL from a starting mbuf. The total number of segments and the
* maximum segments in any one mbuf are provided.
*/
static void
write_tx_sgl(void *dst, struct mbuf *start, struct mbuf *stop, int nsegs, int n)
{
struct mbuf *m;
struct ulptx_sgl *usgl = dst;
int i, j, rc;
struct sglist sg;
struct sglist_seg segs[n];
KASSERT(nsegs > 0, ("%s: nsegs 0", __func__));
sglist_init(&sg, n, segs);
usgl->cmd_nsge = htobe32(V_ULPTX_CMD(ULP_TX_SC_DSGL) |
V_ULPTX_NSGE(nsegs));
i = -1;
for (m = start; m != stop; m = m->m_next) {
rc = sglist_append(&sg, mtod(m, void *), m->m_len);
if (__predict_false(rc != 0))
panic("%s: sglist_append %d", __func__, rc);
for (j = 0; j < sg.sg_nseg; i++, j++) {
if (i < 0) {
usgl->len0 = htobe32(segs[j].ss_len);
usgl->addr0 = htobe64(segs[j].ss_paddr);
} else {
usgl->sge[i / 2].len[i & 1] =
htobe32(segs[j].ss_len);
usgl->sge[i / 2].addr[i & 1] =
htobe64(segs[j].ss_paddr);
}
#ifdef INVARIANTS
nsegs--;
#endif
}
sglist_reset(&sg);
}
if (i & 1)
usgl->sge[i / 2].len[1] = htobe32(0);
KASSERT(nsegs == 0, ("%s: nsegs %d, start %p, stop %p",
__func__, nsegs, start, stop));
}
