netxen: add hardware LRO support

Add support to handle aggregate packets from firmware.
Local TCP flows are automatically identified by firmware
based on the dest IP hash added by driver for local IP
addresses.

The packets are sent down on the jumbo rx ring.

Signed-off-by: Narender Kumar <narender.kumar@qlogic.com>
Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 102 insertions, 22 deletions

diff --git a/drivers/net/netxen/netxen_nic_init.c b/drivers/net/netxen/netxen_nic_init.c
index 81253abbfa34..582828756ef4 100644
--- a/drivers/net/netxen/netxen_nic_init.c
+++ b/drivers/net/netxen/netxen_nic_init.c
@@ -1242,20 +1242,31 @@ no_skb:
 
 static struct netxen_rx_buffer *
 netxen_process_rcv(struct netxen_adapter *adapter,
-		int ring, int index, int length, int cksum, int pkt_offset,
-		struct nx_host_sds_ring *sds_ring)
+		struct nx_host_sds_ring *sds_ring,
+		int ring, u64 sts_data0)
 {
 	struct net_device *netdev = adapter->netdev;
 	struct netxen_recv_context *recv_ctx = &adapter->recv_ctx;
 	struct netxen_rx_buffer *buffer;
 	struct sk_buff *skb;
-	struct nx_host_rds_ring *rds_ring = &recv_ctx->rds_rings[ring];
+	struct nx_host_rds_ring *rds_ring;
+	int index, length, cksum, pkt_offset;
 
-	if (unlikely(index > rds_ring->num_desc))
+	if (unlikely(ring >= adapter->max_rds_rings))
+		return NULL;
+
+	rds_ring = &recv_ctx->rds_rings[ring];
+
+	index = netxen_get_sts_refhandle(sts_data0);
+	if (unlikely(index >= rds_ring->num_desc))
 		return NULL;
 
 	buffer = &rds_ring->rx_buf_arr[index];
 
+	length = netxen_get_sts_totallength(sts_data0);
+	cksum  = netxen_get_sts_status(sts_data0);
+	pkt_offset = netxen_get_sts_pkt_offset(sts_data0);
+
 	skb = netxen_process_rxbuf(adapter, rds_ring, index, cksum);
 	if (!skb)
 		return buffer;
@@ -1279,6 +1290,78 @@ netxen_process_rcv(struct netxen_adapter *adapter,
 	return buffer;
 }
 
+#define TCP_HDR_SIZE            20
+#define TCP_TS_OPTION_SIZE      12
+#define TCP_TS_HDR_SIZE         (TCP_HDR_SIZE + TCP_TS_OPTION_SIZE)
+
+static struct netxen_rx_buffer *
+netxen_process_lro(struct netxen_adapter *adapter,
+		struct nx_host_sds_ring *sds_ring,
+		int ring, u64 sts_data0, u64 sts_data1)
+{
+	struct net_device *netdev = adapter->netdev;
+	struct netxen_recv_context *recv_ctx = &adapter->recv_ctx;
+	struct netxen_rx_buffer *buffer;
+	struct sk_buff *skb;
+	struct nx_host_rds_ring *rds_ring;
+	struct iphdr *iph;
+	struct tcphdr *th;
+	bool push, timestamp;
+	int l2_hdr_offset, l4_hdr_offset;
+	int index;
+	u16 lro_length, length, data_offset;
+	u32 seq_number;
+
+	if (unlikely(ring > adapter->max_rds_rings))
+		return NULL;
+
+	rds_ring = &recv_ctx->rds_rings[ring];
+
+	index = netxen_get_lro_sts_refhandle(sts_data0);
+	if (unlikely(index > rds_ring->num_desc))
+		return NULL;
+
+	buffer = &rds_ring->rx_buf_arr[index];
+
+	timestamp = netxen_get_lro_sts_timestamp(sts_data0);
+	lro_length = netxen_get_lro_sts_length(sts_data0);
+	l2_hdr_offset = netxen_get_lro_sts_l2_hdr_offset(sts_data0);
+	l4_hdr_offset = netxen_get_lro_sts_l4_hdr_offset(sts_data0);
+	push = netxen_get_lro_sts_push_flag(sts_data0);
+	seq_number = netxen_get_lro_sts_seq_number(sts_data1);
+
+	skb = netxen_process_rxbuf(adapter, rds_ring, index, STATUS_CKSUM_OK);
+	if (!skb)
+		return buffer;
+
+	if (timestamp)
+		data_offset = l4_hdr_offset + TCP_TS_HDR_SIZE;
+	else
+		data_offset = l4_hdr_offset + TCP_HDR_SIZE;
+
+	skb_put(skb, lro_length + data_offset);
+
+	skb->truesize = (skb->len + sizeof(struct sk_buff) +
+			((unsigned long)skb->data - (unsigned long)skb->head));
+
+	skb_pull(skb, l2_hdr_offset);
+	skb->protocol = eth_type_trans(skb, netdev);
+
+	iph = (struct iphdr *)skb->data;
+	th = (struct tcphdr *)(skb->data + (iph->ihl << 2));
+
+	length = (iph->ihl << 2) + (th->doff << 2) + lro_length;
+	iph->tot_len = htons(length);
+	iph->check = 0;
+	iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
+	th->psh = push;
+	th->seq = htonl(seq_number);
+
+	netif_receive_skb(skb);
+
+	return buffer;
+}
+
 #define netxen_merge_rx_buffers(list, head) \
 	do { list_splice_tail_init(list, head); } while (0);
 
@@ -1295,28 +1378,33 @@ netxen_process_rcv_ring(struct nx_host_sds_ring *sds_ring, int max)
 	u32 consumer = sds_ring->consumer;
 
 	int count = 0;
-	u64 sts_data;
-	int opcode, ring, index, length, cksum, pkt_offset, desc_cnt;
+	u64 sts_data0, sts_data1;
+	int opcode, ring = 0, desc_cnt;
 
 	while (count < max) {
 		desc = &sds_ring->desc_head[consumer];
-		sts_data = le64_to_cpu(desc->status_desc_data[0]);
+		sts_data0 = le64_to_cpu(desc->status_desc_data[0]);
 
-		if (!(sts_data & STATUS_OWNER_HOST))
+		if (!(sts_data0 & STATUS_OWNER_HOST))
 			break;
 
-		desc_cnt = netxen_get_sts_desc_cnt(sts_data);
-		ring   = netxen_get_sts_type(sts_data);
+		desc_cnt = netxen_get_sts_desc_cnt(sts_data0);
 
-		if (ring > RCV_RING_JUMBO)
-			goto skip;
-
-		opcode = netxen_get_sts_opcode(sts_data);
+		opcode = netxen_get_sts_opcode(sts_data0);
 
 		switch (opcode) {
 		case NETXEN_NIC_RXPKT_DESC:
 		case NETXEN_OLD_RXPKT_DESC:
 		case NETXEN_NIC_SYN_OFFLOAD:
+			ring = netxen_get_sts_type(sts_data0);
+			rxbuf = netxen_process_rcv(adapter, sds_ring,
+					ring, sts_data0);
+			break;
+		case NETXEN_NIC_LRO_DESC:
+			ring = netxen_get_lro_sts_type(sts_data0);
+			sts_data1 = le64_to_cpu(desc->status_desc_data[1]);
+			rxbuf = netxen_process_lro(adapter, sds_ring,
+					ring, sts_data0, sts_data1);
 			break;
 		case NETXEN_NIC_RESPONSE_DESC:
 			netxen_handle_fw_message(desc_cnt, consumer, sds_ring);
@@ -1326,14 +1414,6 @@ netxen_process_rcv_ring(struct nx_host_sds_ring *sds_ring, int max)
 
 		WARN_ON(desc_cnt > 1);
 
-		index  = netxen_get_sts_refhandle(sts_data);
-		length = netxen_get_sts_totallength(sts_data);
-		cksum  = netxen_get_sts_status(sts_data);
-		pkt_offset = netxen_get_sts_pkt_offset(sts_data);
-
-		rxbuf = netxen_process_rcv(adapter, ring, index,
-				length, cksum, pkt_offset, sds_ring);
-
 		if (rxbuf)
 			list_add_tail(&rxbuf->list, &sds_ring->free_list[ring]);