s390/qeth: unionize next-hop field in qeth L3 header

The L3 packet descriptor's 'dest_addr' field is used for a different
purpose in RX descriptors. Clean up the hard-coded byte accesses and
try to be more self-documenting.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 100f7cce02607fb2f1f4f79be435e45284c5dfde..db42107bf2f5f040734ebbda0ea8abaf7453edbc 100644 (file)
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -297,8 +297,23 @@ struct qeth_hdr_layer3 {
        __u8  ext_flags;
        __u16 vlan_id;
        __u16 frame_offset;
-       __u8  dest_addr[16];
-} __attribute__ ((packed));
+       union {
+               /* TX: */
+               u8 ipv6_addr[16];
+               struct ipv4 {
+                       u8 res[12];
+                       u32 addr;
+               } ipv4;
+               /* RX: */
+               struct rx {
+                       u8 res1[2];
+                       u8 src_mac[6];
+                       u8 res2[4];
+                       u16 vlan_id;
+                       u8 res3[2];
+               } rx;
+       } next_hop;
+};
 
 struct qeth_hdr_layer2 {
        __u8 id;

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index e168719c4b93fc53fb7054a083f2513461fdb024..4723ed9831eb318914d8c248cb39ef3f8da24e21 100644 (file)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -1637,7 +1637,7 @@ static void qeth_l3_rebuild_skb(struct qeth_card *card, struct sk_buff *skb,
                }
                if (hdr->hdr.l3.ext_flags & QETH_HDR_EXT_SRC_MAC_ADDR)
                        card->dev->header_ops->create(skb, card->dev, prot,
-                               tg_addr, &hdr->hdr.l3.dest_addr[2],
+                               tg_addr, &hdr->hdr.l3.next_hop.rx.src_mac,
                                card->dev->addr_len);
                else
                        card->dev->header_ops->create(skb, card->dev, prot,
@@ -1652,7 +1652,7 @@ static void qeth_l3_rebuild_skb(struct qeth_card *card, struct sk_buff *skb,
                                      QETH_HDR_EXT_INCLUDE_VLAN_TAG))) {
                u16 tag = (hdr->hdr.l3.ext_flags & QETH_HDR_EXT_VLAN_FRAME) ?
                                hdr->hdr.l3.vlan_id :
-                               *((u16 *)&hdr->hdr.l3.dest_addr[12]);
+                               hdr->hdr.l3.next_hop.rx.vlan_id;
                __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), tag);
        }
 
@@ -2408,7 +2408,7 @@ static void qeth_l3_fill_af_iucv_hdr(struct qeth_card *card,
        daddr[0] = 0xfe;
        daddr[1] = 0x80;
        memcpy(&daddr[8], iucv_hdr->destUserID, 8);
-       memcpy(hdr->hdr.l3.dest_addr, daddr, 16);
+       memcpy(hdr->hdr.l3.next_hop.ipv6_addr, daddr, 16);
 }
 
 static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
@@ -2445,8 +2445,8 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
 
                /* IPv4 */
                hdr->hdr.l3.flags = qeth_l3_get_qeth_hdr_flags4(cast_type);
-               memset(hdr->hdr.l3.dest_addr, 0, 12);
-               *((__be32 *) (&hdr->hdr.l3.dest_addr[12])) = *pkey;
+               memset(hdr->hdr.l3.next_hop.ipv4.res, 0, 12);
+               *((__be32 *) &hdr->hdr.l3.next_hop.ipv4.addr) = *pkey;
        } else if (ipv == 6) {
                struct rt6_info *rt = (struct rt6_info *) dst;
                struct in6_addr *pkey = &ipv6_hdr(skb)->daddr;
@@ -2458,7 +2458,7 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
                hdr->hdr.l3.flags = qeth_l3_get_qeth_hdr_flags6(cast_type);
                if (card->info.type == QETH_CARD_TYPE_IQD)
                        hdr->hdr.l3.flags &= ~QETH_HDR_PASSTHRU;
-               memcpy(hdr->hdr.l3.dest_addr, pkey, 16);
+               memcpy(hdr->hdr.l3.next_hop.ipv6_addr, pkey, 16);
        } else {
                if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest,
                                            skb->dev->broadcast)) {