svn commit: r243008 - user/andre/tcp_workqueue/sys/dev/fxp

[Andre Oppermann]

Author: andre
Date: Tue Nov 13 22:35:31 2012
New Revision: 243008
URL: http://svnweb.freebsd.org/changeset/base/243008

Log:
  Simplify checksum offload test based on chip revision.
  
  Comment out RX checksum code for really lame 82559 chip.
  It's probably better to have stack handle that, rather
  than faking it by manually.
  
  Fix and enable small packet copy to mbuf.  Packets smaller
  than MHLEN (eg. TCP ACK) are copied into a new mbuf.  The
  cluster can stay in the RX DMA ring and get reused instead
  of wasted on a very small packet.
  
  Tested on 82559 (A0) and 82550 (C) though it does sometime
  wedge in a very weird way.  A up/down cycles clears it again.

Modified:
  user/andre/tcp_workqueue/sys/dev/fxp/if_fxp.c

Modified: user/andre/tcp_workqueue/sys/dev/fxp/if_fxp.c
==============================================================================
--- user/andre/tcp_workqueue/sys/dev/fxp/if_fxp.c	Tue Nov 13 22:01:25 2012	(r243007)
+++ user/andre/tcp_workqueue/sys/dev/fxp/if_fxp.c	Tue Nov 13 22:35:31 2012	(r243008)
@@ -637,9 +637,7 @@ fxp_attach(device_t dev)
 	 * too, but that's already enabled by the code above.
 	 * Be careful to do this only on the right devices.
 	 */
-	if (sc->revision == FXP_REV_82550 || sc->revision == FXP_REV_82550_C ||
-	    sc->revision == FXP_REV_82551_E || sc->revision == FXP_REV_82551_F
-	    || sc->revision == FXP_REV_82551_10) {
+	if (sc->revision >= FXP_REV_82550) {
 		sc->rfa_size = sizeof (struct fxp_rfa);
 		sc->tx_cmd = FXP_CB_COMMAND_IPCBXMIT;
 		sc->flags |= FXP_FLAG_EXT_RFA;
@@ -1471,7 +1469,6 @@ fxp_encap(struct fxp_softc *sc, struct m
 		/* Compute total TCP payload. */
 		tcp_payload = m->m_pkthdr.len - ip_off - (ip->ip_hl << 2);
 		tcp_payload -= tcp->th_off << 2;
-		*m_head = m;
 	} else if (m->m_pkthdr.csum_flags & FXP_CSUM_FEATURES) {
 		/*
 		 * Deal with TCP/IP checksum offload. Note that
@@ -1735,14 +1732,15 @@ static void
 fxp_rxcsum(struct fxp_softc *sc, struct ifnet *ifp, struct mbuf *m,
     uint16_t status, int pos)
 {
+#if 0
 	struct ether_header *eh;
 	struct ip *ip;
 	struct udphdr *uh;
 	int32_t hlen, len, pktlen, temp32;
 	uint16_t csum, *opts;
-
-	if ((sc->flags & FXP_FLAG_82559_RXCSUM) == 0) {
-		if ((status & FXP_RFA_STATUS_PARSE) != 0) {
+#endif
+	if (!(sc->flags & FXP_FLAG_82559_RXCSUM)) {
+		if (status & FXP_RFA_STATUS_PARSE) {
 			if (status & FXP_RFDX_CS_IP_CSUM_BIT_VALID)
 				m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED;
 			if (status & FXP_RFDX_CS_IP_CSUM_VALID)
@@ -1757,6 +1755,11 @@ fxp_rxcsum(struct fxp_softc *sc, struct 
 		return;
 	}
 
+	/*
+	 * XXXAO: Does it really make sense to touch the packet
+	 * when the checksum feature on 559 is so lame?
+	 */
+#if 0
 	pktlen = m->m_pkthdr.len;
 	if (pktlen < sizeof(struct ether_header) + sizeof(struct ip))
 		return;
@@ -1805,8 +1808,10 @@ fxp_rxcsum(struct fxp_softc *sc, struct 
 			csum = temp32 & 65535;
 		}
 	}
+	/* XXXAO: Missing subtraction of ip_hdr checksum? */
 	m->m_pkthdr.csum_flags |= CSUM_DATA_VALID;
 	m->m_pkthdr.csum_data = csum;
+#endif
 }
 
 /*
@@ -1827,8 +1832,10 @@ fxp_rx(struct fxp_softc *sc, struct ifne
 	struct fxp_rx *rxp;
 	struct fxp_rfa *rfa;
 	struct mbuf *m, *n, *m0;
-	int len, rnr = 0;
-	uint16_t status;
+	int rnr = 0;
+	uint16_t len, status, vlan;
+
+	m = n = NULL;		/* gcc */
 
 	for (;;) {
 		rxp = sc->fxp_desc.rx_head;
@@ -1852,12 +1859,13 @@ fxp_rx(struct fxp_softc *sc, struct ifne
 		 * actual_size are flags set by the controller
 		 * upon completion), and drop the packet in case
 		 * of bogus length or CRC errors.
-		 * Adjust for appended checksum bytes.
+		 * Adjust for appended checksum word for 559
+		 * checksum offload 'feature'.
 		 */
 		len = le16toh(rfa->actual_size) & 0x3fff;
 		if ((sc->flags & FXP_FLAG_82559_RXCSUM) &&
 		    (ifp->if_capenable & IFCAP_RXCSUM))
-			len -= ETHER_CRC_LEN;
+			len -= 2;
 
 		if (len < (int)sizeof(struct ether_header) ||
 		    len > (MCLBYTES - ETHER_ALIGN - sc->rfa_size) ||
@@ -1867,12 +1875,14 @@ fxp_rx(struct fxp_softc *sc, struct ifne
 			fxp_add_rfabuf(sc, rxp);
 			continue;
 		}
-		if (1 == 0 && len <= MHLEN - ETHER_ALIGN &&
-		    (m0 = m_get(M_NOWAIT, MT_DATA)) != NULL) {
+		vlan = ntohs(rfa->rfax_vlan_id);
+
+		if (len <= MHLEN - ETHER_ALIGN &&
+		    (m0 = m_gethdr(M_NOWAIT, MT_DATA)) != NULL) {
 			/* Copy stuff over. */
-			m_adj(m0, ETHER_ALIGN);
-			(void)m_append(m0, len,
-			    (caddr_t)(&rxp->rx_mbuf->m_ext.ext_buf));
+			m0->m_data += ETHER_ALIGN;
+			(void)m_append(m0, len, mtod(rxp->rx_mbuf, caddr_t));
+			rfa = NULL;
 			fxp_discard_rfabuf(sc, rxp);
 		} else if (fxp_new_rfabuf(sc, rxp) > 0) {
 			/*
@@ -1896,8 +1906,7 @@ fxp_rx(struct fxp_softc *sc, struct ifne
 
 		if ((ifp->if_capenable & IFCAP_VLAN_HWTAGGING) != 0 &&
 		    (status & FXP_RFA_STATUS_VLAN) != 0) {
-			m0->m_pkthdr.ether_vtag =
-			    ntohs(rfa->rfax_vlan_id);
+			m0->m_pkthdr.ether_vtag = vlan;
 			m0->m_flags |= M_VLANTAG;
 		}