implement the completion half of the tx path. the driver keeps track of

mbufs we've put on the hardware with the nxe_pkt struct. this struct
contains a unique id for each pkt which is used the hardwares tx descriptor
so we could identify which pkts its finished transmitting. turns out the
hardware doesnt return ids though, it tells us which slots in the tx ring
its up to. so now i stash the slot a pkt went into in the pkt_id field.

1 files changed, 54 insertions, 4 deletions

diff --git a/sys/dev/pci/if_nxe.c b/sys/dev/pci/if_nxe.c
index 0b1edbf7c12..2ba4f24858b 100644
--- a/sys/dev/pci/if_nxe.c
+++ b/sys/dev/pci/if_nxe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_nxe.c,v 1.45 2007/08/23 13:31:39 dlg Exp $ */
+/*	$OpenBSD: if_nxe.c,v 1.46 2007/08/23 13:52:29 dlg Exp $ */
 
 /*
  * Copyright (c) 2007 David Gwynne <dlg@openbsd.org>
@@ -650,7 +650,7 @@ struct nxe_dmamem {
 #define NXE_DMA_KVA(_ndm)	((void *)(_ndm)->ndm_kva)
 
 struct nxe_pkt {
-	u_int16_t		pkt_id;
+	int			pkt_id;
 	bus_dmamap_t		pkt_dmap;
 	struct mbuf		*pkt_m;
 	TAILQ_ENTRY(nxe_pkt)	pkt_link;
@@ -712,6 +712,7 @@ struct nxe_softc {
 
 	struct nxe_dmamem	*sc_ctx;
 	u_int32_t		*sc_cmd_consumer;
+	u_int32_t		sc_cmd_consumer_cur;
 
 	struct nxe_ring		*sc_cmd_ring;
 	struct nxe_ring		*sc_rx_rings[NXE_NRING];
@@ -760,6 +761,7 @@ void			nxe_link_state(struct nxe_softc *);
 /* interface operations */
 int			nxe_ioctl(struct ifnet *, u_long, caddr_t);
 void			nxe_start(struct ifnet *);
+int			nxe_complete(struct nxe_softc *);
 void			nxe_watchdog(struct ifnet *);
 
 void			nxe_up(struct nxe_softc *);
@@ -1101,6 +1103,7 @@ nxe_up(struct nxe_softc *sc)
 	ctx->ctx_id = htole32(sc->sc_function);
 
 	sc->sc_cmd_consumer = &dmamem->cmd_consumer;
+	sc->sc_cmd_consumer_cur = 0;
 
 	/* allocate the cmd/tx ring */
 	sc->sc_cmd_ring = nxe_ring_alloc(sc,
@@ -1287,7 +1290,7 @@ nxe_start(struct ifnet *ifp)
 	    IFQ_IS_EMPTY(&ifp->if_snd))
 		return;
 
-	if (nxe_ring_writeable(nr, 0 /* XXX */) < NXE_TXD_DESCS) {
+	if (nxe_ring_writeable(nr, sc->sc_cmd_consumer_cur) < NXE_TXD_DESCS) {
 		SET(ifp->if_flags, IFF_OACTIVE);
 		return;
 	}
@@ -1327,7 +1330,6 @@ nxe_start(struct ifnet *ifp)
 		txd->tx_flags = htole16(NXE_TXD_F_OPCODE_TX);
 		txd->tx_nbufs = dmap->dm_nsegs;
 		txd->tx_length = htole16(dmap->dm_mapsize);
-		txd->tx_id = pkt->pkt_id;
 		txd->tx_port = sc->sc_port;
 
 		segs = dmap->dm_segs;
@@ -1356,6 +1358,8 @@ nxe_start(struct ifnet *ifp)
 			nsegs -= NXE_TXD_SEGS;
 			segs += NXE_TXD_SEGS;
 
+			pkt->pkt_id = nr->nr_slot;
+
 			txd = nxe_ring_next(sc, nr);
 			bzero(txd, sizeof(struct nxe_tx_desc));
 		} while (nsegs > 0);
@@ -1370,6 +1374,52 @@ nxe_start(struct ifnet *ifp)
 	nxe_crb_write(sc, NXE_1_SW_CMD_PRODUCER(sc->sc_function), nr->nr_slot);
 }
 
+int
+nxe_complete(struct nxe_softc *sc)
+{
+	struct nxe_pkt			*pkt;
+	int				new_cons, cur_cons;
+	int				rv = 0;
+
+	bus_dmamap_sync(sc->sc_dmat, NXE_DMA_MAP(sc->sc_ctx),
+	    0, NXE_DMA_LEN(sc->sc_ctx),
+	    BUS_DMASYNC_POSTWRITE | BUS_DMASYNC_POSTREAD);
+	new_cons = letoh32(*sc->sc_cmd_consumer);
+	bus_dmamap_sync(sc->sc_dmat, NXE_DMA_MAP(sc->sc_ctx),
+	    0, NXE_DMA_LEN(sc->sc_ctx),
+	    BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD);
+
+	cur_cons = sc->sc_cmd_consumer_cur;
+	pkt = nxe_pkt_used(sc->sc_tx_pkts);
+
+	while (pkt != NULL && cur_cons != new_cons) {
+		if (pkt->pkt_id == cur_cons) {
+			bus_dmamap_sync(sc->sc_dmat, pkt->pkt_dmap,
+			    0, pkt->pkt_dmap->dm_mapsize,
+			    BUS_DMASYNC_POSTWRITE);
+			    bus_dmamap_unload(sc->sc_dmat, pkt->pkt_dmap);
+
+			m_freem(pkt->pkt_m);
+
+			nxe_pkt_put(sc->sc_tx_pkts, pkt);
+
+			pkt = nxe_pkt_used(sc->sc_tx_pkts);
+		}
+
+		cur_cons++;
+		cur_cons %= sc->sc_cmd_ring->nr_nentries;
+
+		rv = 1;
+	}
+
+	if (rv == 1) {
+		sc->sc_cmd_consumer_cur = cur_cons;
+		CLR(sc->sc_ac.ac_if.if_flags, IFF_OACTIVE);
+	}
+
+	return (rv);
+}
+
 struct mbuf *
 nxe_coalesce_m(struct mbuf *m)
 {