previous commit causes gcc to perform an unaligned access to the tcphdr

(at least on sparc64) since it accesses the bitfield using an "int sized"
instructions, rather than the minimally sized byte instruction.  This is
permitted by the language laywers who probably prefer we change the tcphdr
in every packet.  It is not clear how to convince gcc to avoid this behaviour,
and a week of futzing hasn't found fast path solutions yet.  In the meantime
the tree may not be broken.

diff --git a/sys/dev/pci/if_ixl.c b/sys/dev/pci/if_ixl.c
index 75b6269..6c91c12 100644 (file)
--- a/sys/dev/pci/if_ixl.c
+++ b/sys/dev/pci/if_ixl.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_ixl.c,v 1.76 2021/11/09 09:26:18 jan Exp $ */
+/*     $OpenBSD: if_ixl.c,v 1.77 2021/11/27 16:25:40 deraadt Exp $ */
 
 /*
  * Copyright (c) 2013-2015, Intel Corporation
@@ -82,10 +82,6 @@
 #endif
 
 #include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/ip6.h>
-#include <netinet/tcp.h>
-#include <netinet/udp.h>
 #include <netinet/if_ether.h>
 
 #include <dev/pci/pcireg.h>
@@ -1392,7 +1388,6 @@ static int        ixl_rxeof(struct ixl_softc *, struct ixl_rx_ring *);
 static void    ixl_rxfill(struct ixl_softc *, struct ixl_rx_ring *);
 static void    ixl_rxrefill(void *);
 static int     ixl_rxrinfo(struct ixl_softc *, struct if_rxrinfo *);
-static void    ixl_rx_checksum(struct mbuf *, uint64_t);
 
 #if NKSTAT > 0
 static void    ixl_kstat_attach(struct ixl_softc *);
@@ -1947,9 +1942,9 @@ ixl_attach(struct device *parent, struct device *self, void *aux)
        ifp->if_capabilities = IFCAP_VLAN_MTU;
 #if 0
        ifp->if_capabilities |= IFCAP_VLAN_HWTAGGING;
-#endif
        ifp->if_capabilities |= IFCAP_CSUM_IPv4 | IFCAP_CSUM_TCPv4 |
-           IFCAP_CSUM_UDPv4 | IFCAP_CSUM_TCPv6 | IFCAP_CSUM_UDPv6;
+           IFCAP_CSUM_UDPv4;
+#endif
 
        ifmedia_init(&sc->sc_media, 0, ixl_media_change, ixl_media_status);
 
@@ -2776,69 +2771,6 @@ ixl_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m)
            BUS_DMA_STREAMING | BUS_DMA_NOWAIT));
 }
 
-static void
-ixl_tx_setup_offload(struct mbuf *mp, uint64_t *cmd)
-{
-       uint64_t         ip_hdr_len;
-       int              ipoff = ETHER_HDR_LEN;
-       uint8_t          ipproto;
-       struct ip       *ip;
-#ifdef INET6
-       struct ip6_hdr  *ip6;
-#endif
-       struct tcphdr   *th;
-       struct mbuf     *m;
-
-       switch (ntohs(mtod(mp, struct ether_header *)->ether_type)) {
-       case ETHERTYPE_IP:
-               if (mp->m_pkthdr.len < ETHER_HDR_LEN + sizeof(*ip))
-                       return;
-               m = m_getptr(mp, ETHER_HDR_LEN, &ipoff);
-               KASSERT(m != NULL && m->m_len - ipoff >= sizeof(*ip));
-               ip = (struct ip *)(m->m_data + ipoff);
-
-               if (mp->m_pkthdr.csum_flags & M_IPV4_CSUM_OUT)
-                       *cmd |= IXL_TX_DESC_CMD_IIPT_IPV4_CSUM;
-               else
-                       *cmd |= IXL_TX_DESC_CMD_IIPT_IPV4;
-
-               ip_hdr_len = ip->ip_hl << 2;
-               ipproto = ip->ip_p;
-               break;
-#ifdef INET6
-       case ETHERTYPE_IPV6:
-               if (mp->m_pkthdr.len < ETHER_HDR_LEN + sizeof(*ip6))
-                       return;
-               m = m_getptr(mp, ETHER_HDR_LEN, &ipoff);
-               KASSERT(m != NULL && m->m_len - ipoff >= sizeof(*ip6));
-               ip6 = (struct ip6_hdr *)(m->m_data + ipoff);
-
-               *cmd |= IXL_TX_DESC_CMD_IIPT_IPV6;
-
-               ip_hdr_len = sizeof(*ip6);
-               ipproto = ip6->ip6_nxt;
-               break;
-#endif
-       default:
-               return;
-       }
-
-       *cmd |= (ETHER_HDR_LEN >> 1) << IXL_TX_DESC_MACLEN_SHIFT;
-       *cmd |= (ip_hdr_len >> 2) << IXL_TX_DESC_IPLEN_SHIFT;
-
-       if (ipproto == IPPROTO_TCP && m->m_pkthdr.csum_flags & M_TCP_CSUM_OUT) {
-               th = (struct tcphdr *)(m->m_data + ipoff + ip_hdr_len);
-
-               *cmd |= IXL_TX_DESC_CMD_L4T_EOFT_TCP;
-               *cmd |= (uint64_t)th->th_off << IXL_TX_DESC_L4LEN_SHIFT;
-       }
-
-       if (ipproto == IPPROTO_UDP && m->m_pkthdr.csum_flags & M_UDP_CSUM_OUT) {
-               *cmd |= IXL_TX_DESC_CMD_L4T_EOFT_UDP;
-               *cmd |= (sizeof(struct udphdr) >> 2) << IXL_TX_DESC_L4LEN_SHIFT;
-       }
-}
-
 static void
 ixl_start(struct ifqueue *ifq)
 {
@@ -2849,7 +2781,7 @@ ixl_start(struct ifqueue *ifq)
        struct ixl_tx_map *txm;
        bus_dmamap_t map;
        struct mbuf *m;
-       uint64_t cmd, off = 0;
+       uint64_t cmd;
        unsigned int prod, free, last, i;
        unsigned int mask;
        int post = 0;
@@ -2896,15 +2828,12 @@ ixl_start(struct ifqueue *ifq)
                bus_dmamap_sync(sc->sc_dmat, map, 0,
                    map->dm_mapsize, BUS_DMASYNC_PREWRITE);
 
-               ixl_tx_setup_offload(m, &off);
-
                for (i = 0; i < map->dm_nsegs; i++) {
                        txd = &ring[prod];
 
                        cmd = (uint64_t)map->dm_segs[i].ds_len <<
                            IXL_TX_DESC_BSIZE_SHIFT;
                        cmd |= IXL_TX_DESC_DTYPE_DATA | IXL_TX_DESC_CMD_ICRC;
-                       cmd |= off;
 
                        htolem64(&txd->addr, map->dm_segs[i].ds_addr);
                        htolem64(&txd->cmd, cmd);
@@ -3261,7 +3190,6 @@ ixl_rxeof(struct ixl_softc *sc, struct ixl_rx_ring *rxr)
                                        m->m_pkthdr.csum_flags |= M_FLOWID;
                                }
 
-                               ixl_rx_checksum(m, word);
                                ml_enqueue(&ml, m);
                        } else {
                                ifp->if_ierrors++; /* XXX */
@@ -3394,23 +3322,6 @@ ixl_rxrinfo(struct ixl_softc *sc, struct if_rxrinfo *ifri)
        return (rv);
 }
 
-static void
-ixl_rx_checksum(struct mbuf *m, uint64_t word)
-{
-       if (!ISSET(word, IXL_RX_DESC_L3L4P))
-               return;
-
-       if (ISSET(word, IXL_RX_DESC_IPE))
-               return;
-
-       m->m_pkthdr.csum_flags |= M_IPV4_CSUM_IN_OK;
-
-       if (ISSET(word, IXL_RX_DESC_L4E))
-               return;
-
-       m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_OK | M_UDP_CSUM_IN_OK;
-}
-
 static int
 ixl_intr0(void *xsc)
 {