RDMA/rxe: Extend rxe_icrc.c to support frags

Extend the subroutines rxe_icrc_generate() and rxe_icrc_check()
to support skb frags.

This is in preparation for supporting fragmented skbs.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>

drivers/infiniband/sw/rxe/rxe_icrc.c

@@ -63,7 +63,7 @@ static __be32 rxe_crc32(struct rxe_dev *rxe, __be32 crc, void *next, size_t len)
 
 /**
  * rxe_icrc_hdr() - Compute the partial ICRC for the network and transport
- *		  headers of a packet.
+ *		    headers of a packet.
  * @skb: packet buffer
  * @pkt: packet information
  *
@@ -129,6 +129,56 @@ static __be32 rxe_icrc_hdr(struct sk_buff *skb, struct rxe_pkt_info *pkt)
 	return crc;
 }
 
+/**
+ * rxe_icrc_payload() - Compute the ICRC for a packet payload and also
+ *			compute the address of the icrc in the packet.
+ * @skb: packet buffer
+ * @pkt: packet information
+ * @icrc: current icrc i.e. including headers
+ * @icrcp: returned pointer to icrc in skb
+ *
+ * Return: 0 if the values match else an error
+ */
+__be32 rxe_icrc_payload(struct sk_buff *skb, struct rxe_pkt_info *pkt,
+			__be32 icrc, __be32 **icrcp)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(skb);
+	skb_frag_t *frag;
+	u8 *addr;
+	int hdr_len;
+	int len;
+	int i;
+
+	/* handle any payload left in the linear buffer */
+	hdr_len = rxe_opcode[pkt->opcode].length;
+	addr = pkt->hdr + hdr_len;
+	len = skb_tail_pointer(skb) - skb_transport_header(skb)
+		- sizeof(struct udphdr) - hdr_len;
+	if (!shinfo->nr_frags) {
+		len -= RXE_ICRC_SIZE;
+		*icrcp = (__be32 *)(addr + len);
+	}
+	if (len > 0)
+		icrc = rxe_crc32(pkt->rxe, icrc, payload_addr(pkt), len);
+	WARN_ON(len < 0);
+
+	/* handle any payload in frags */
+	for (i = 0; i < shinfo->nr_frags; i++) {
+		frag = &shinfo->frags[i];
+		addr = page_to_virt(frag->bv_page) + frag->bv_offset;
+		len = frag->bv_len;
+		if (i == shinfo->nr_frags - 1) {
+			len -= RXE_ICRC_SIZE;
+			*icrcp = (__be32 *)(addr + len);
+		}
+		if (len > 0)
+			icrc = rxe_crc32(pkt->rxe, icrc, addr, len);
+		WARN_ON(len < 0);
+	}
+
+	return icrc;
+}
+
 /**
  * rxe_icrc_check() - Compute ICRC for a packet and compare to the ICRC
  *		      delivered in the packet.
@@ -143,13 +193,11 @@ int rxe_icrc_check(struct sk_buff *skb, struct rxe_pkt_info *pkt)
 	__be32 pkt_icrc;
 	__be32 icrc;
 
-	icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE);
-	pkt_icrc = *icrcp;
-
 	icrc = rxe_icrc_hdr(skb, pkt);
-	icrc = rxe_crc32(pkt->rxe, icrc, (u8 *)payload_addr(pkt),
-				payload_size(pkt) + bth_pad(pkt));
+	icrc = rxe_icrc_payload(skb, pkt, icrc, &icrcp);
+
 	icrc = ~icrc;
+	pkt_icrc = *icrcp;
 
 	if (unlikely(icrc != pkt_icrc))
 		return -EINVAL;
@@ -167,9 +215,8 @@ void rxe_icrc_generate(struct sk_buff *skb, struct rxe_pkt_info *pkt)
 	__be32 *icrcp;
 	__be32 icrc;
 
-	icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE);
 	icrc = rxe_icrc_hdr(skb, pkt);
-	icrc = rxe_crc32(pkt->rxe, icrc, (u8 *)payload_addr(pkt),
-				payload_size(pkt) + bth_pad(pkt));
+	icrc = rxe_icrc_payload(skb, pkt, icrc, &icrcp);
+
 	*icrcp = ~icrc;
 }

drivers/infiniband/sw/rxe/rxe_net.c

@@ -134,32 +134,51 @@ static int rxe_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	struct rxe_dev *rxe;
 	struct net_device *ndev = skb->dev;
 	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
+	u8 opcode;
+	u8 buf[1];
+	u8 *p;
 
-	/* takes a reference on rxe->ib_dev
-	 * drop when skb is freed
-	 */
+	/* Takes a reference on rxe->ib_dev. Drop when skb is freed */
 	rxe = rxe_get_dev_from_net(ndev);
 	if (!rxe && is_vlan_dev(ndev))
 		rxe = rxe_get_dev_from_net(vlan_dev_real_dev(ndev));
 	if (!rxe)
-		goto drop;
+		goto err_drop;
 
-	if (skb_linearize(skb)) {
-		ib_device_put(&rxe->ib_dev);
-		goto drop;
+	/* Get bth opcode out of skb */
+	p = skb_header_pointer(skb, sizeof(struct udphdr), 1, buf);
+	if (!p)
+		goto err_device_put;
+	opcode = *p;
+
+	/* If using fragmented skbs make sure roce headers
+	 * are in linear buffer else make skb linear
+	 */
+	if (rxe_use_sg && skb_is_nonlinear(skb)) {
+		int delta = rxe_opcode[opcode].length -
+			(skb_headlen(skb) - sizeof(struct udphdr));
+
+		if (delta > 0 && !__pskb_pull_tail(skb, delta))
+			goto err_device_put;
+	} else {
+		if (skb_linearize(skb))
+			goto err_device_put;
 	}
 
 	udph = udp_hdr(skb);
 	pkt->rxe = rxe;
 	pkt->port_num = 1;
 	pkt->hdr = (u8 *)(udph + 1);
-	pkt->mask = RXE_GRH_MASK;
+	pkt->mask = rxe_opcode[opcode].mask | RXE_GRH_MASK;
 	pkt->paylen = be16_to_cpu(udph->len) - sizeof(*udph);
 
 	rxe_rcv(skb);
 
 	return 0;
-drop:
+
+err_device_put:
+	ib_device_put(&rxe->ib_dev);
+err_drop:
 	kfree_skb(skb);
 
 	return 0;
@@ -385,21 +404,32 @@ static int rxe_send(struct sk_buff *skb, struct rxe_pkt_info *pkt)
  */
 static int rxe_loopback(struct sk_buff *skb, struct rxe_pkt_info *pkt)
 {
-	memcpy(SKB_TO_PKT(skb), pkt, sizeof(*pkt));
+	struct rxe_pkt_info *newpkt;
+	int err;
 
+	/* make loopback line up with rxe_udp_encap_recv */
 	if (skb->protocol == htons(ETH_P_IP))
 		skb_pull(skb, sizeof(struct iphdr));
 	else
 		skb_pull(skb, sizeof(struct ipv6hdr));
+	skb_reset_transport_header(skb);
+
+	newpkt = SKB_TO_PKT(skb);
+	memcpy(newpkt, pkt, sizeof(*newpkt));
+	newpkt->hdr = skb_transport_header(skb) + sizeof(struct udphdr);
 
 	if (WARN_ON(!ib_device_try_get(&pkt->rxe->ib_dev))) {
 		kfree_skb(skb);
-		return -EIO;
+		err = -EINVAL;
+		goto drop;
 	}
 
 	rxe_rcv(skb);
-
 	return 0;
+
+drop:
+	kfree_skb(skb);
+	return err;
 }
 
 int rxe_xmit_packet(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
@@ -415,6 +445,7 @@ int rxe_xmit_packet(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
 		goto drop;
 	}
 
+	/* skb->data points at IP header */
 	rxe_icrc_generate(skb, pkt);
 
 	if (pkt->mask & RXE_LOOPBACK_MASK)

drivers/infiniband/sw/rxe/rxe_recv.c

@@ -329,6 +329,7 @@ void rxe_rcv(struct sk_buff *skb)
 	if (unlikely(err))
 		goto drop;
 
+	/* skb->data points at UDP header */
 	err = rxe_icrc_check(skb, pkt);
 	if (unlikely(err))
 		goto drop;