Implement TSO and TSO over VLAN. Increase number of allowed

fragmentation of mbuf chain to 32 from 16 because TSO can send 64KB
sized packet which in turn requires long list of mbuf chain. Due to
lack of documentation, I'm not sure whether driver have to pull up
ethernet/IP/TCP header with options to make controller work but
driver have to parse TCP header to update pseudo TCP checksum
anyway. The controller expects pseudo TCP checksum computed by
upper stack and the checksum should follow the MS NDIS
specification to make TSO work.

Tested by:	xclin <xclin <> cs dot nctu dot edu dot tw >

1 files changed, 100 insertions, 14 deletions

diff --git a/sys/dev/sge/if_sge.c b/sys/dev/sge/if_sge.c
index ee88cb6..14c2b94 100644
--- a/sys/dev/sge/if_sge.c
+++ b/sys/dev/sge/if_sge.c
@@ -72,8 +72,13 @@ __FBSDID("$FreeBSD$");
 #include <net/if_types.h>
 #include <net/if_vlan_var.h>
 
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+
 #include <machine/bus.h>
-#include <machine/resource.h>
+#include <machine/in_cksum.h>
 
 #include <dev/mii/mii.h>
 #include <dev/mii/miivar.h>
@@ -620,8 +625,8 @@ sge_attach(device_t dev)
 	ifp->if_snd.ifq_drv_maxlen = SGE_TX_RING_CNT - 1;
 	IFQ_SET_MAXLEN(&ifp->if_snd, ifp->if_snd.ifq_drv_maxlen);
 	IFQ_SET_READY(&ifp->if_snd);
-	ifp->if_capabilities = IFCAP_TXCSUM | IFCAP_RXCSUM;
-	ifp->if_hwassist = SGE_CSUM_FEATURES;
+	ifp->if_capabilities = IFCAP_TXCSUM | IFCAP_RXCSUM | IFCAP_TSO4;
+	ifp->if_hwassist = SGE_CSUM_FEATURES | CSUM_TSO;
 	ifp->if_capenable = ifp->if_capabilities;
 	/*
 	 * Do MII setup.
@@ -641,7 +646,7 @@ sge_attach(device_t dev)
 	/* VLAN setup. */
 	if ((sc->sge_flags & SGE_FLAG_SIS190) == 0)
 		ifp->if_capabilities |= IFCAP_VLAN_HWTAGGING |
-		    IFCAP_VLAN_HWCSUM;
+		    IFCAP_VLAN_HWCSUM | IFCAP_VLAN_HWTSO;
 	ifp->if_capabilities |= IFCAP_VLAN_MTU;
 	ifp->if_capenable = ifp->if_capabilities;
 	/* Tell the upper layer(s) we support long frames. */
@@ -851,8 +856,8 @@ sge_dma_alloc(struct sge_softc *sc)
 
 	/* Create DMA tag for Tx buffers. */
 	error = bus_dma_tag_create(cd->sge_tag, 1, 0, BUS_SPACE_MAXADDR,
-	    BUS_SPACE_MAXADDR, NULL, NULL, MCLBYTES * SGE_MAXTXSEGS,
-	    SGE_MAXTXSEGS, MCLBYTES, 0, NULL, NULL, &cd->sge_txmbuf_tag);
+	    BUS_SPACE_MAXADDR, NULL, NULL, SGE_TSO_MAXSIZE, SGE_MAXTXSEGS,
+	    SGE_TSO_MAXSEGSIZE, 0, NULL, NULL, &cd->sge_txmbuf_tag);
 	if (error != 0) {
 		device_printf(sc->sge_dev,
 		    "could not create Tx mbuf DMA tag.\n");
@@ -1424,13 +1429,73 @@ sge_encap(struct sge_softc *sc, struct mbuf **m_head)
 	struct sge_desc *desc;
 	struct sge_txdesc *txd;
 	bus_dma_segment_t txsegs[SGE_MAXTXSEGS];
-	uint32_t cflags;
+	uint32_t cflags, mss;
 	int error, i, nsegs, prod, si;
 
 	SGE_LOCK_ASSERT(sc);
 
 	si = prod = sc->sge_cdata.sge_tx_prod;
 	txd = &sc->sge_cdata.sge_txdesc[prod];
+	if (((*m_head)->m_pkthdr.csum_flags & CSUM_TSO) != 0) {
+		struct ether_header *eh;
+		struct ip *ip;
+		struct tcphdr *tcp;
+		uint32_t ip_off, poff;
+
+		if (M_WRITABLE(*m_head) == 0) {
+			/* Get a writable copy. */
+			m = m_dup(*m_head, M_DONTWAIT);
+			m_freem(*m_head);
+			if (m == NULL) {
+				*m_head = NULL;
+				return (ENOBUFS);
+			}
+			*m_head = m;
+		}
+		ip_off = sizeof(struct ether_header);
+		m = m_pullup(*m_head, ip_off);
+		if (m == NULL) {
+			*m_head = NULL;
+			return (ENOBUFS);
+		}
+		eh = mtod(m, struct ether_header *);
+		/* Check the existence of VLAN tag. */
+		if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
+			ip_off = sizeof(struct ether_vlan_header);
+			m = m_pullup(m, ip_off);
+			if (m == NULL) {
+				*m_head = NULL;
+				return (ENOBUFS);
+			}
+		}
+		m = m_pullup(m, ip_off + sizeof(struct ip));
+		if (m == NULL) {
+			*m_head = NULL;
+			return (ENOBUFS);
+		}
+		ip = (struct ip *)(mtod(m, char *) + ip_off);
+		poff = ip_off + (ip->ip_hl << 2);
+		m = m_pullup(m, poff + sizeof(struct tcphdr));
+		if (m == NULL) {
+			*m_head = NULL;
+			return (ENOBUFS);
+		}
+		tcp = (struct tcphdr *)(mtod(m, char *) + poff);
+		m = m_pullup(m, poff + (tcp->th_off << 2));
+		if (m == NULL) {
+			*m_head = NULL;
+			return (ENOBUFS);
+		}
+		/*
+		 * Reset IP checksum and recompute TCP pseudo
+		 * checksum that NDIS specification requires.
+		 */
+		ip->ip_sum = 0;
+		tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
+		    htons(IPPROTO_TCP));
+		*m_head = m;
+	}
+
 	error = bus_dmamap_load_mbuf_sg(sc->sge_cdata.sge_txmbuf_tag,
 	    txd->tx_dmamap, *m_head, txsegs, &nsegs, 0);
 	if (error == EFBIG) {
@@ -1462,16 +1527,23 @@ sge_encap(struct sge_softc *sc, struct mbuf **m_head)
 
 	m = *m_head;
 	cflags = 0;
-	if (m->m_pkthdr.csum_flags & CSUM_IP)
-		cflags |= TDC_IP_CSUM;
-	if (m->m_pkthdr.csum_flags & CSUM_TCP)
-		cflags |= TDC_TCP_CSUM;
-	if (m->m_pkthdr.csum_flags & CSUM_UDP)
-		cflags |= TDC_UDP_CSUM;
+	mss = 0;
+	if ((m->m_pkthdr.csum_flags & CSUM_TSO) != 0) {
+		cflags |= TDC_LS;
+		mss = (uint32_t)m->m_pkthdr.tso_segsz;
+		mss <<= 16;
+	} else {
+		if (m->m_pkthdr.csum_flags & CSUM_IP)
+			cflags |= TDC_IP_CSUM;
+		if (m->m_pkthdr.csum_flags & CSUM_TCP)
+			cflags |= TDC_TCP_CSUM;
+		if (m->m_pkthdr.csum_flags & CSUM_UDP)
+			cflags |= TDC_UDP_CSUM;
+	}
 	for (i = 0; i < nsegs; i++) {
 		desc = &sc->sge_ldata.sge_tx_ring[prod];
 		if (i == 0) {
-			desc->sge_sts_size = htole32(m->m_pkthdr.len);
+			desc->sge_sts_size = htole32(m->m_pkthdr.len | mss);
 			desc->sge_cmdsts = 0;
 		} else {
 			desc->sge_sts_size = 0;
@@ -1759,6 +1831,17 @@ sge_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 		if ((mask & IFCAP_VLAN_HWCSUM) != 0 &&
 		    (ifp->if_capabilities & IFCAP_VLAN_HWCSUM) != 0)
 			ifp->if_capenable ^= IFCAP_VLAN_HWCSUM;
+		if ((mask & IFCAP_TSO4) != 0 &&
+		    (ifp->if_capabilities & IFCAP_TSO4) != 0) {
+			ifp->if_capenable ^= IFCAP_TSO4;
+			if ((ifp->if_capenable & IFCAP_TSO4) != 0)
+				ifp->if_hwassist |= CSUM_TSO;
+			else
+				ifp->if_hwassist &= ~CSUM_TSO;
+		}
+		if ((mask & IFCAP_VLAN_HWTSO) != 0 &&
+		    (ifp->if_capabilities & IFCAP_VLAN_HWTSO) != 0)
+			ifp->if_capenable ^= IFCAP_VLAN_HWTSO;
 		if ((mask & IFCAP_VLAN_HWTAGGING) != 0 &&
 		    (ifp->if_capabilities & IFCAP_VLAN_HWTAGGING) != 0) {
 			/*
@@ -1766,6 +1849,9 @@ sge_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 			 * tagging require interface reinitialization.
 			 */
 			ifp->if_capenable ^= IFCAP_VLAN_HWTAGGING;
+			if ((ifp->if_capenable & IFCAP_VLAN_HWTAGGING) == 0)
+				ifp->if_capenable &=
+				    ~(IFCAP_VLAN_HWTSO | IFCAP_VLAN_HWCSUM);
 			reinit = 1;
 		}
 		if (reinit > 0 && (ifp->if_drv_flags & IFF_DRV_RUNNING) != 0) {