Remove RX checksum offloading support. The chip is too limited, and

examining higher protocol layers to adjust the checksum and calculate
the pseudo-header in the driver is too complex to be worthwhile.
ok henning@

1 files changed, 2 insertions, 104 deletions

diff --git a/sys/dev/ic/hme.c b/sys/dev/ic/hme.c
index 803008f5610..bc66d37194d 100644
--- a/sys/dev/ic/hme.c
+++ b/sys/dev/ic/hme.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hme.c,v 1.63 2013/08/07 01:06:29 bluhm Exp $	*/
+/*	$OpenBSD: hme.c,v 1.64 2014/04/22 15:52:05 naddy Exp $	*/
 /*	$NetBSD: hme.c,v 1.21 2001/07/07 15:59:37 thorpej Exp $	*/
 
 /*-
@@ -105,8 +105,6 @@ void		hme_mediastatus(struct ifnet *, struct ifmediareq *);
 int		hme_eint(struct hme_softc *, u_int);
 int		hme_rint(struct hme_softc *);
 int		hme_tint(struct hme_softc *);
-/* TCP/UDP checksum offload support */
-void 		hme_rxcksum(struct mbuf *, u_int32_t);
 
 void
 hme_config(sc)
@@ -516,7 +514,7 @@ hme_init(sc)
 	bus_space_handle_t erx = sc->sc_erx;
 	bus_space_handle_t mac = sc->sc_mac;
 	u_int8_t *ea;
-	u_int32_t v, n;
+	u_int32_t v;
 
 	/*
 	 * Initialization sequence. The numbered steps below correspond
@@ -625,10 +623,6 @@ hme_init(sc)
 #endif
 	/* Enable DMA */
 	v |= HME_ERX_CFG_DMAENABLE | (HME_RX_OFFSET << 3);
-	/* RX TCP/UDP cksum offset */
-	n = (ETHER_HDR_LEN + sizeof(struct ip)) / 2;
-	n = (n << HME_ERX_CFG_CSUM_SHIFT) & HME_ERX_CFG_CSUMSTART;
-	v |= n;
 	bus_space_write_4(t, erx, HME_ERXI_CFG, v);
 
 	/* step 11. XIF Configuration */
@@ -831,101 +825,6 @@ hme_tint(sc)
 }
 
 /*
- * XXX layering violation
- *
- * If we can have additional csum data member in 'struct pkthdr' for
- * these incomplete checksum offload capable hardware, things would be
- * much simpler. That member variable will carry partial checksum
- * data and it may be evaluated in TCP/UDP input handler after
- * computing pseudo header checksumming.
- */
-void
-hme_rxcksum(struct mbuf *m, u_int32_t flags)
-{
-	struct ether_header *eh;
-	struct ip *ip;
-	struct udphdr *uh;
-	int32_t hlen, len, pktlen;
-	u_int16_t cksum, *opts;
-	u_int32_t temp32;
-	union pseudoh {
-		struct hdr {
-			u_int16_t len;
-			u_int8_t ttl;
-			u_int8_t proto;
-			u_int32_t src;
-			u_int32_t dst;
-		} h;
-		u_int16_t w[6];
-	} ph;
-
-	pktlen = m->m_pkthdr.len;
-	if (pktlen < sizeof(struct ether_header))
-		return;
-	eh = mtod(m, struct ether_header *);
-	if (eh->ether_type != htons(ETHERTYPE_IP))
-		return;
-	ip = (struct ip *)(eh + 1);
-	if (ip->ip_v != IPVERSION)
-		return;
-
-	hlen = ip->ip_hl << 2;
-	pktlen -= sizeof(struct ether_header);
-	if (hlen < sizeof(struct ip))
-		return;
-	if (ntohs(ip->ip_len) < hlen)
-		return;
-	if (ntohs(ip->ip_len) != pktlen) 
-		return;
-	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
-		return;	/* can't handle fragmented packet */
-
-	switch (ip->ip_p) {
-	case IPPROTO_TCP:
-		if (pktlen < (hlen + sizeof(struct tcphdr)))
-			return;
-		break;
-	case IPPROTO_UDP:
-		if (pktlen < (hlen + sizeof(struct udphdr)))
-			return;
-		uh = (struct udphdr *)((caddr_t)ip + hlen);
-		if (uh->uh_sum == 0)
-			return; /* no checksum */
-		break;
-	default:
-		return;
-	}
-
-	cksum = htons(~(flags & HME_XD_RXCKSUM));
-	/* cksum fixup for IP options */
-	len = hlen - sizeof(struct ip);
-	if (len > 0) {
-		opts = (u_int16_t *)(ip + 1);
-		for (; len > 0; len -= sizeof(u_int16_t), opts++) {
-			temp32 = cksum - *opts;
-			temp32 = (temp32 >> 16) + (temp32 & 65535);
-			cksum = temp32 & 65535;
-		}
-	}
-	/* cksum fixup for pseudo-header, replace with in_cksum_phdr()? */
-	ph.h.len = htons(ntohs(ip->ip_len) - hlen);
-	ph.h.ttl = 0;
-	ph.h.proto = ip->ip_p;
-	ph.h.src = ip->ip_src.s_addr;
-	ph.h.dst = ip->ip_dst.s_addr;
-	temp32 = cksum;
-	opts = &ph.w[0];
-	temp32 += opts[0] + opts[1] + opts[2] + opts[3] + opts[4] + opts[5];
-	temp32 = (temp32 >> 16) + (temp32 & 65535);
-	temp32 += (temp32 >> 16);
-	cksum = ~temp32;
-	if (cksum == 0) {
-		m->m_pkthdr.csum_flags |=
-			M_TCP_CSUM_IN_OK | M_UDP_CSUM_IN_OK;
-	}
-}
-
-/*
  * Receive interrupt.
  */
 int
@@ -975,7 +874,6 @@ hme_rint(sc)
 		m->m_pkthdr.len = m->m_len = len;
 
 		ifp->if_ipackets++;
-		hme_rxcksum(m, flags);
 
 #if NBPFILTER > 0
 		if (ifp->if_bpf)