vmx(4) uses 4 different types of 128bit descriptors in little-endian

format for Rx and Tx.  Replace the bit fields in the descriptor
structs with 32bit words to access them with traditional bit
operations using shifts and masks.  We try to avoid bit fields in
OpenBSD.  For consistence with other drivers, this change also uses
letoh32/htole32 endianess conversions even if it is very unlikely that
vmx will ever run on a big-endian VM/host.

discussed with uebayasi@ and deraadt@

1 files changed, 51 insertions, 39 deletions

diff --git a/sys/dev/pci/if_vmx.c b/sys/dev/pci/if_vmx.c
index 24f0ef75494..24d6997877b 100644
--- a/sys/dev/pci/if_vmx.c
+++ b/sys/dev/pci/if_vmx.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vmx.c,v 1.11 2013/06/22 00:28:10 uebayasi Exp $	*/
+/*	$OpenBSD: if_vmx.c,v 1.12 2013/08/28 10:19:19 reyk Exp $	*/
 
 /*
  * Copyright (c) 2013 Tsubai Masanari
@@ -645,7 +645,9 @@ vmxnet3_txintr(struct vmxnet3_softc *sc, struct vmxnet3_txqueue *tq)
 
 	for (;;) {
 		txcd = &comp_ring->txcd[comp_ring->next];
-		if (txcd->gen != comp_ring->gen)
+
+		if (letoh32((txcd->txc_word3 >> VMXNET3_TXC_GEN_S) &
+		    VMXNET3_TXC_GEN_M) != comp_ring->gen)
 			break;
 
 		comp_ring->next++;
@@ -660,7 +662,9 @@ vmxnet3_txintr(struct vmxnet3_softc *sc, struct vmxnet3_txqueue *tq)
 		m_freem(ring->m[sop]);
 		ring->m[sop] = NULL;
 		bus_dmamap_unload(sc->sc_dmat, ring->dmap[sop]);
-		ring->next = (txcd->eop_idx + 1) % NTXDESC;
+		ring->next = (letoh32((txcd->txc_word0 >>
+		    VMXNET3_TXC_EOPIDX_S) & VMXNET3_TXC_EOPIDX_M) + 1)
+		    % NTXDESC;
 
 		ifp->if_flags &= ~IFF_OACTIVE;
 	}
@@ -682,7 +686,8 @@ vmxnet3_rxintr(struct vmxnet3_softc *sc, struct vmxnet3_rxqueue *rq)
 
 	for (;;) {
 		rxcd = &comp_ring->rxcd[comp_ring->next];
-		if (rxcd->gen != comp_ring->gen)
+		if (letoh32((rxcd->rxc_word3 >> VMXNET3_RXC_GEN_S) &
+		    VMXNET3_RXC_GEN_M) != comp_ring->gen)
 			break;
 
 		comp_ring->next++;
@@ -691,13 +696,16 @@ vmxnet3_rxintr(struct vmxnet3_softc *sc, struct vmxnet3_rxqueue *rq)
 			comp_ring->gen ^= 1;
 		}
 
-		idx = rxcd->rxd_idx;
-		if (rxcd->qid < NRXQUEUE)
+		idx = letoh32((rxcd->rxc_word0 >> VMXNET3_RXC_IDX_S) &
+		    VMXNET3_RXC_IDX_M);
+		if (letoh32((rxcd->rxc_word0 >> VMXNET3_RXC_QID_S) &
+		    VMXNET3_RXC_QID_M) < NRXQUEUE)
 			ring = &rq->cmd_ring[0];
 		else
 			ring = &rq->cmd_ring[1];
 		rxd = &ring->rxd[idx];
-		len = rxcd->len;
+		len = letoh32((rxcd->rxc_word2 >> VMXNET3_RXC_LEN_S) &
+		    VMXNET3_RXC_LEN_M);
 		m = ring->m[idx];
 		ring->m[idx] = NULL;
 		bus_dmamap_unload(sc->sc_dmat, ring->dmap[idx]);
@@ -705,11 +713,12 @@ vmxnet3_rxintr(struct vmxnet3_softc *sc, struct vmxnet3_rxqueue *rq)
 		if (m == NULL)
 			panic("NULL mbuf");
 
-		if (rxd->btype != VMXNET3_BTYPE_HEAD) {
+		if (letoh32((rxd->rx_word2 >> VMXNET3_RX_BTYPE_S) &
+		    VMXNET3_RX_BTYPE_M) != VMXNET3_BTYPE_HEAD) {
 			m_freem(m);
 			goto skip_buffer;
 		}
-		if (rxcd->error) {
+		if (letoh32(rxcd->rxc_word2 & VMXNET3_RXC_ERROR)) {
 			ifp->if_ierrors++;
 			m_freem(m);
 			goto skip_buffer;
@@ -726,9 +735,10 @@ vmxnet3_rxintr(struct vmxnet3_softc *sc, struct vmxnet3_rxqueue *rq)
 		vmxnet3_rx_csum(rxcd, m);
 		m->m_pkthdr.rcvif = ifp;
 		m->m_pkthdr.len = m->m_len = len;
-		if (rxcd->vlan) {
+		if (letoh32(rxcd->rxc_word2 & VMXNET3_RXC_VLAN)) {
 			m->m_flags |= M_VLANTAG;
-			m->m_pkthdr.ether_vtag = rxcd->vtag;
+			m->m_pkthdr.ether_vtag = letoh32((rxcd->rxc_word2 >>
+			    VMXNET3_RXC_VLANTAG_S) & VMXNET3_RXC_VLANTAG_M);
 		}
 
 #if NBPFILTER > 0
@@ -742,7 +752,8 @@ skip_buffer:
 		vmxstat.rxdone = idx;
 #endif
 		if (rq->rs->update_rxhead) {
-			u_int qid = rxcd->qid;
+			u_int qid = letoh32((rxcd->rxc_word0 >>
+			    VMXNET3_RXC_QID_S) & VMXNET3_RXC_QID_M);
 
 			idx = (idx + 1) % NRXDESC;
 			if (qid < NRXQUEUE) {
@@ -811,23 +822,24 @@ vmxnet3_iff(struct vmxnet3_softc *sc)
 void
 vmxnet3_rx_csum(struct vmxnet3_rxcompdesc *rxcd, struct mbuf *m)
 {
-	if (rxcd->no_csum)
+	if (letoh32(rxcd->rxc_word0 & VMXNET3_RXC_NOCSUM))
 		return;
 
-	if (rxcd->ipv4 && rxcd->ipcsum_ok)
+	if ((rxcd->rxc_word3 & (VMXNET3_RXC_IPV4|VMXNET3_RXC_IPSUM_OK)) ==
+	    (VMXNET3_RXC_IPV4|VMXNET3_RXC_IPSUM_OK))
 		m->m_pkthdr.csum_flags |= M_IPV4_CSUM_IN_OK;
 
-	if (rxcd->fragment)
+	if (rxcd->rxc_word3 & VMXNET3_RXC_FRAGMENT)
 		return;
 
-	if (rxcd->tcp) {
-		if (rxcd->csum_ok)
+	if (rxcd->rxc_word3 & VMXNET3_RXC_TCP) {
+		if (rxcd->rxc_word3 & VMXNET3_RXC_CSUM_OK)
 			m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_OK;
 		else
 			m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_BAD;
 	}
-	if (rxcd->udp) {
-		if (rxcd->csum_ok)
+	if (rxcd->rxc_word3 & VMXNET3_RXC_UDP) {
+		if (rxcd->rxc_word3 & VMXNET3_RXC_CSUM_OK)
 			m->m_pkthdr.csum_flags |= M_UDP_CSUM_IN_OK;
 		else
 			m->m_pkthdr.csum_flags |= M_UDP_CSUM_IN_BAD;
@@ -873,10 +885,11 @@ vmxnet3_getbuf(struct vmxnet3_softc *sc, struct vmxnet3_rxring *ring)
 	if (bus_dmamap_load_mbuf(sc->sc_dmat, ring->dmap[idx], m,
 	    BUS_DMA_NOWAIT))
 		panic("load mbuf");
-	rxd->addr = DMAADDR(ring->dmap[idx]);
-	rxd->btype = btype;
-	rxd->len = m->m_pkthdr.len;
-	rxd->gen = ring->gen;
+	rxd->rx_addr = htole64(DMAADDR(ring->dmap[idx]));
+	rxd->rx_word2 = htole32(((m->m_pkthdr.len & VMXNET3_RX_LEN_M) <<
+	    VMXNET3_RX_LEN_S) | ((btype & VMXNET3_RX_BTYPE_M) <<
+	    VMXNET3_RX_BTYPE_S) | ((ring->gen & VMXNET3_RX_GEN_M) <<
+	    VMXNET3_RX_GEN_S));
 	idx++;
 	if (idx == NRXDESC) {
 		idx = 0;
@@ -1118,14 +1131,11 @@ vmxnet3_load_mbuf(struct vmxnet3_softc *sc, struct mbuf *m)
 	gen = ring->gen ^ 1;		/* owned by cpu (yet) */
 	for (i = 0; i < map->dm_nsegs; i++) {
 		txd = &ring->txd[ring->head];
-		txd->addr = map->dm_segs[i].ds_addr;
-		txd->len = map->dm_segs[i].ds_len;
-		txd->gen = gen;
-		txd->dtype = 0;
-		txd->offload_mode = VMXNET3_OM_NONE;
-		txd->offload_pos = txd->hlen = 0;
-		txd->eop = txd->compreq = 0;
-		txd->vtag_mode = txd->vtag = 0;
+		txd->tx_addr = htole64(map->dm_segs[i].ds_addr);
+		txd->tx_word2 = htole32(((map->dm_segs[i].ds_len &
+		    VMXNET3_TX_LEN_M) << VMXNET3_TX_LEN_S) |
+		    ((gen & VMXNET3_TX_GEN_M) << VMXNET3_TX_GEN_S));
+		txd->tx_word3 = 0;
 		ring->head++;
 		if (ring->head == NTXDESC) {
 			ring->head = 0;
@@ -1133,20 +1143,22 @@ vmxnet3_load_mbuf(struct vmxnet3_softc *sc, struct mbuf *m)
 		}
 		gen = ring->gen;
 	}
-	txd->eop = txd->compreq = 1;
+	txd->tx_word3 |= htole32(VMXNET3_TX_EOP | VMXNET3_TX_COMPREQ);
 
 	if (m->m_flags & M_VLANTAG) {
-		sop->vtag_mode = 1;
-		sop->vtag = m->m_pkthdr.ether_vtag;
+		sop->tx_word3 |= htole32(VMXNET3_TX_VTAG_MODE);
+		sop->tx_word3 |= htole32((m->m_pkthdr.ether_vtag &
+		    VMXNET3_TX_VLANTAG_M) << VMXNET3_TX_VLANTAG_S);
 	}
 	if (m->m_pkthdr.csum_flags & (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT)) {
-		sop->offload_mode = VMXNET3_OM_CSUM;
-		sop->hlen = hlen;
-		sop->offload_pos = hlen + csum_off;
+		sop->tx_word2 |= htole32(((hlen + csum_off) &
+		    VMXNET3_TX_OP_M) << VMXNET3_TX_OP_S);
+		sop->tx_word3 |= htole32(((hlen & VMXNET3_TX_HLEN_M) <<
+		    VMXNET3_TX_HLEN_S) | (VMXNET3_OM_CSUM << VMXNET3_TX_OM_S));
 	}
 
-	/* Change the ownership. */
-	sop->gen ^= 1;
+	/* Change the ownership by flipping the "generation" bit */
+	sop->tx_word2 ^= htole32(VMXNET3_TX_GEN_M << VMXNET3_TX_GEN_S);
 
 	return (0);
 }