MFC r207851:

  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 >

2 files changed, 103 insertions, 15 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) {
diff --git a/sys/dev/sge/if_sgereg.h b/sys/dev/sge/if_sgereg.h
index c06072c..6987e99 100644
--- a/sys/dev/sge/if_sgereg.h
+++ b/sys/dev/sge/if_sgereg.h
@@ -283,7 +283,9 @@ struct sge_desc {
 #define	SGE_RX_RING_CNT		256 /* [8, 1024] */
 #define	SGE_TX_RING_CNT		256 /* [8, 8192] */
 #define	SGE_DESC_ALIGN		16
-#define	SGE_MAXTXSEGS		16
+#define	SGE_MAXTXSEGS		32
+#define	SGE_TSO_MAXSIZE		(65535 + sizeof(struct ether_vlan_header))
+#define	SGE_TSO_MAXSEGSIZE	4096
 #define	SGE_RX_BUF_ALIGN	sizeof(uint64_t)
 
 #define	SGE_RX_RING_SZ		(SGE_RX_RING_CNT * sizeof(struct sge_desc))