ixgbe: Add one function that handles most of context descriptor setup

There is a significant amount of shared functionality between the checksum
and TSO offload configuration that is shared in regards to how they setup
the context descriptors.  Since so much of the functionality is shared it
makes sense to move the shared functionality into a single function and
just call that function from the two context descriptor specific routines.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 129 insertions, 166 deletions

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 4fbe077..00e60c5 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -35,6 +35,7 @@
 #include <linux/interrupt.h>
 #include <linux/ip.h>
 #include <linux/tcp.h>
+#include <linux/sctp.h>
 #include <linux/pkt_sched.h>
 #include <linux/ipv6.h>
 #include <linux/slab.h>
@@ -6353,179 +6354,145 @@ static void ixgbe_service_task(struct work_struct *work)
 	ixgbe_service_event_complete(adapter);
 }
 
-static int ixgbe_tso(struct ixgbe_adapter *adapter,
-		     struct ixgbe_ring *tx_ring, struct sk_buff *skb,
-		     u32 tx_flags, u8 *hdr_len, __be16 protocol)
+void ixgbe_tx_ctxtdesc(struct ixgbe_ring *tx_ring, u32 vlan_macip_lens,
+		       u32 fcoe_sof_eof, u32 type_tucmd, u32 mss_l4len_idx)
 {
 	struct ixgbe_adv_tx_context_desc *context_desc;
-	unsigned int i;
-	int err;
-	struct ixgbe_tx_buffer *tx_buffer_info;
-	u32 vlan_macip_lens = 0, type_tucmd_mlhl;
-	u32 mss_l4len_idx, l4len;
+	u16 i = tx_ring->next_to_use;
 
-	if (skb_is_gso(skb)) {
-		if (skb_header_cloned(skb)) {
-			err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
-			if (err)
-				return err;
-		}
-		l4len = tcp_hdrlen(skb);
-		*hdr_len += l4len;
-
-		if (protocol == htons(ETH_P_IP)) {
-			struct iphdr *iph = ip_hdr(skb);
-			iph->tot_len = 0;
-			iph->check = 0;
-			tcp_hdr(skb)->check = ~csum_tcpudp_magic(iph->saddr,
-								 iph->daddr, 0,
-								 IPPROTO_TCP,
-								 0);
-		} else if (skb_is_gso_v6(skb)) {
-			ipv6_hdr(skb)->payload_len = 0;
-			tcp_hdr(skb)->check =
-			    ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
-					     &ipv6_hdr(skb)->daddr,
-					     0, IPPROTO_TCP, 0);
-		}
+	context_desc = IXGBE_TX_CTXTDESC_ADV(tx_ring, i);
 
-		i = tx_ring->next_to_use;
+	i++;
+	tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
 
-		tx_buffer_info = &tx_ring->tx_buffer_info[i];
-		context_desc = IXGBE_TX_CTXTDESC_ADV(tx_ring, i);
-
-		/* VLAN MACLEN IPLEN */
-		if (tx_flags & IXGBE_TX_FLAGS_VLAN)
-			vlan_macip_lens |=
-			    (tx_flags & IXGBE_TX_FLAGS_VLAN_MASK);
-		vlan_macip_lens |= ((skb_network_offset(skb)) <<
-				    IXGBE_ADVTXD_MACLEN_SHIFT);
-		*hdr_len += skb_network_offset(skb);
-		vlan_macip_lens |=
-		    (skb_transport_header(skb) - skb_network_header(skb));
-		*hdr_len +=
-		    (skb_transport_header(skb) - skb_network_header(skb));
-		context_desc->vlan_macip_lens = cpu_to_le32(vlan_macip_lens);
-		context_desc->seqnum_seed = 0;
-
-		/* ADV DTYP TUCMD MKRLOC/ISCSIHEDLEN */
-		type_tucmd_mlhl = (IXGBE_TXD_CMD_DEXT |
-				   IXGBE_ADVTXD_DTYP_CTXT);
+	/* set bits to identify this as an advanced context descriptor */
+	type_tucmd |= IXGBE_TXD_CMD_DEXT | IXGBE_ADVTXD_DTYP_CTXT;
 
-		if (protocol == htons(ETH_P_IP))
-			type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_IPV4;
-		type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
-		context_desc->type_tucmd_mlhl = cpu_to_le32(type_tucmd_mlhl);
-
-		/* MSS L4LEN IDX */
-		mss_l4len_idx =
-		    (skb_shinfo(skb)->gso_size << IXGBE_ADVTXD_MSS_SHIFT);
-		mss_l4len_idx |= (l4len << IXGBE_ADVTXD_L4LEN_SHIFT);
-		/* use index 1 for TSO */
-		mss_l4len_idx |= (1 << IXGBE_ADVTXD_IDX_SHIFT);
-		context_desc->mss_l4len_idx = cpu_to_le32(mss_l4len_idx);
+	context_desc->vlan_macip_lens	= cpu_to_le32(vlan_macip_lens);
+	context_desc->seqnum_seed	= cpu_to_le32(fcoe_sof_eof);
+	context_desc->type_tucmd_mlhl	= cpu_to_le32(type_tucmd);
+	context_desc->mss_l4len_idx	= cpu_to_le32(mss_l4len_idx);
+}
 
-		tx_buffer_info->time_stamp = jiffies;
-		tx_buffer_info->next_to_watch = i;
+static int ixgbe_tso(struct ixgbe_ring *tx_ring, struct sk_buff *skb,
+		     u32 tx_flags, __be16 protocol, u8 *hdr_len)
+{
+	int err;
+	u32 vlan_macip_lens, type_tucmd;
+	u32 mss_l4len_idx, l4len;
 
-		i++;
-		if (i == tx_ring->count)
-			i = 0;
-		tx_ring->next_to_use = i;
+	if (!skb_is_gso(skb))
+		return 0;
 
-		return true;
+	if (skb_header_cloned(skb)) {
+		err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+		if (err)
+			return err;
 	}
-	return false;
-}
 
-static u32 ixgbe_psum(struct ixgbe_adapter *adapter, struct sk_buff *skb,
-		      __be16 protocol)
+	/* ADV DTYP TUCMD MKRLOC/ISCSIHEDLEN */
+	type_tucmd = IXGBE_ADVTXD_TUCMD_L4T_TCP;
+
+	if (protocol == __constant_htons(ETH_P_IP)) {
+		struct iphdr *iph = ip_hdr(skb);
+		iph->tot_len = 0;
+		iph->check = 0;
+		tcp_hdr(skb)->check = ~csum_tcpudp_magic(iph->saddr,
+							 iph->daddr, 0,
+							 IPPROTO_TCP,
+							 0);
+		type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
+	} else if (skb_is_gso_v6(skb)) {
+		ipv6_hdr(skb)->payload_len = 0;
+		tcp_hdr(skb)->check =
+		    ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+				     &ipv6_hdr(skb)->daddr,
+				     0, IPPROTO_TCP, 0);
+	}
+
+	l4len = tcp_hdrlen(skb);
+	*hdr_len = skb_transport_offset(skb) + l4len;
+
+	/* mss_l4len_id: use 1 as index for TSO */
+	mss_l4len_idx = l4len << IXGBE_ADVTXD_L4LEN_SHIFT;
+	mss_l4len_idx |= skb_shinfo(skb)->gso_size << IXGBE_ADVTXD_MSS_SHIFT;
+	mss_l4len_idx |= 1 << IXGBE_ADVTXD_IDX_SHIFT;
+
+	/* vlan_macip_lens: HEADLEN, MACLEN, VLAN tag */
+	vlan_macip_lens = skb_network_header_len(skb);
+	vlan_macip_lens |= skb_network_offset(skb) << IXGBE_ADVTXD_MACLEN_SHIFT;
+	vlan_macip_lens |= tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
+
+	ixgbe_tx_ctxtdesc(tx_ring, vlan_macip_lens, 0, type_tucmd,
+	                  mss_l4len_idx);
+
+	return 1;
+}
+
+static bool ixgbe_tx_csum(struct ixgbe_ring *tx_ring,
+			  struct sk_buff *skb, u32 tx_flags,
+			  __be16 protocol)
 {
-	u32 rtn = 0;
+	u32 vlan_macip_lens = 0;
+	u32 mss_l4len_idx = 0;
+	u32 type_tucmd = 0;
 
-	switch (protocol) {
-	case cpu_to_be16(ETH_P_IP):
-		rtn |= IXGBE_ADVTXD_TUCMD_IPV4;
-		switch (ip_hdr(skb)->protocol) {
-		case IPPROTO_TCP:
-			rtn |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+	    if (!(tx_flags & IXGBE_TX_FLAGS_VLAN))
+			return false;
+	} else {
+		u8 l4_hdr = 0;
+		switch (protocol) {
+		case __constant_htons(ETH_P_IP):
+			vlan_macip_lens |= skb_network_header_len(skb);
+			type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
+			l4_hdr = ip_hdr(skb)->protocol;
 			break;
-		case IPPROTO_SCTP:
-			rtn |= IXGBE_ADVTXD_TUCMD_L4T_SCTP;
+		case __constant_htons(ETH_P_IPV6):
+			vlan_macip_lens |= skb_network_header_len(skb);
+			l4_hdr = ipv6_hdr(skb)->nexthdr;
+			break;
+		default:
+			if (unlikely(net_ratelimit())) {
+				dev_warn(tx_ring->dev,
+				 "partial checksum but proto=%x!\n",
+				 skb->protocol);
+			}
 			break;
 		}
-		break;
-	case cpu_to_be16(ETH_P_IPV6):
-		/* XXX what about other V6 headers?? */
-		switch (ipv6_hdr(skb)->nexthdr) {
+
+		switch (l4_hdr) {
 		case IPPROTO_TCP:
-			rtn |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
+			type_tucmd |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
+			mss_l4len_idx = tcp_hdrlen(skb) <<
+					IXGBE_ADVTXD_L4LEN_SHIFT;
 			break;
 		case IPPROTO_SCTP:
-			rtn |= IXGBE_ADVTXD_TUCMD_L4T_SCTP;
+			type_tucmd |= IXGBE_ADVTXD_TUCMD_L4T_SCTP;
+			mss_l4len_idx = sizeof(struct sctphdr) <<
+					IXGBE_ADVTXD_L4LEN_SHIFT;
+			break;
+		case IPPROTO_UDP:
+			mss_l4len_idx = sizeof(struct udphdr) <<
+					IXGBE_ADVTXD_L4LEN_SHIFT;
+			break;
+		default:
+			if (unlikely(net_ratelimit())) {
+				dev_warn(tx_ring->dev,
+				 "partial checksum but l4 proto=%x!\n",
+				 skb->protocol);
+			}
 			break;
 		}
-		break;
-	default:
-		if (unlikely(net_ratelimit()))
-			e_warn(probe, "partial checksum but proto=%x!\n",
-			       protocol);
-		break;
 	}
 
-	return rtn;
-}
-
-static bool ixgbe_tx_csum(struct ixgbe_adapter *adapter,
-			  struct ixgbe_ring *tx_ring,
-			  struct sk_buff *skb, u32 tx_flags,
-			  __be16 protocol)
-{
-	struct ixgbe_adv_tx_context_desc *context_desc;
-	unsigned int i;
-	struct ixgbe_tx_buffer *tx_buffer_info;
-	u32 vlan_macip_lens = 0, type_tucmd_mlhl = 0;
-
-	if (skb->ip_summed == CHECKSUM_PARTIAL ||
-	    (tx_flags & IXGBE_TX_FLAGS_VLAN)) {
-		i = tx_ring->next_to_use;
-		tx_buffer_info = &tx_ring->tx_buffer_info[i];
-		context_desc = IXGBE_TX_CTXTDESC_ADV(tx_ring, i);
-
-		if (tx_flags & IXGBE_TX_FLAGS_VLAN)
-			vlan_macip_lens |=
-			    (tx_flags & IXGBE_TX_FLAGS_VLAN_MASK);
-		vlan_macip_lens |= (skb_network_offset(skb) <<
-				    IXGBE_ADVTXD_MACLEN_SHIFT);
-		if (skb->ip_summed == CHECKSUM_PARTIAL)
-			vlan_macip_lens |= (skb_transport_header(skb) -
-					    skb_network_header(skb));
-
-		context_desc->vlan_macip_lens = cpu_to_le32(vlan_macip_lens);
-		context_desc->seqnum_seed = 0;
+	vlan_macip_lens |= skb_network_offset(skb) << IXGBE_ADVTXD_MACLEN_SHIFT;
+	vlan_macip_lens |= tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
 
-		type_tucmd_mlhl |= (IXGBE_TXD_CMD_DEXT |
-				    IXGBE_ADVTXD_DTYP_CTXT);
+	ixgbe_tx_ctxtdesc(tx_ring, vlan_macip_lens, 0,
+			  type_tucmd, mss_l4len_idx);
 
-		if (skb->ip_summed == CHECKSUM_PARTIAL)
-			type_tucmd_mlhl |= ixgbe_psum(adapter, skb, protocol);
-
-		context_desc->type_tucmd_mlhl = cpu_to_le32(type_tucmd_mlhl);
-		/* use index zero for tx checksum offload */
-		context_desc->mss_l4len_idx = 0;
-
-		tx_buffer_info->time_stamp = jiffies;
-		tx_buffer_info->next_to_watch = i;
-
-		i++;
-		if (i == tx_ring->count)
-			i = 0;
-		tx_ring->next_to_use = i;
-
-		return true;
-	}
-
-	return false;
+	return (skb->ip_summed == CHECKSUM_PARTIAL);
 }
 
 static int ixgbe_tx_map(struct ixgbe_adapter *adapter,
@@ -6918,29 +6885,21 @@ netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb,
 	if (tx_flags & IXGBE_TX_FLAGS_FCOE) {
 #ifdef IXGBE_FCOE
 		/* setup tx offload for FCoE */
-		tso = ixgbe_fso(adapter, tx_ring, skb, tx_flags, &hdr_len);
-		if (tso < 0) {
-			dev_kfree_skb_any(skb);
-			return NETDEV_TX_OK;
-		}
-		if (tso)
+		tso = ixgbe_fso(tx_ring, skb, tx_flags, &hdr_len);
+		if (tso < 0)
+			goto out_drop;
+		else if (tso)
 			tx_flags |= IXGBE_TX_FLAGS_FSO;
 #endif /* IXGBE_FCOE */
 	} else {
 		if (protocol == htons(ETH_P_IP))
 			tx_flags |= IXGBE_TX_FLAGS_IPV4;
-		tso = ixgbe_tso(adapter, tx_ring, skb, tx_flags, &hdr_len,
-				protocol);
-		if (tso < 0) {
-			dev_kfree_skb_any(skb);
-			return NETDEV_TX_OK;
-		}
-
-		if (tso)
+		tso = ixgbe_tso(tx_ring, skb, tx_flags, protocol, &hdr_len);
+		if (tso < 0)
+			goto out_drop;
+		else if (tso)
 			tx_flags |= IXGBE_TX_FLAGS_TSO;
-		else if (ixgbe_tx_csum(adapter, tx_ring, skb, tx_flags,
-				       protocol) &&
-			 (skb->ip_summed == CHECKSUM_PARTIAL))
+		else if (ixgbe_tx_csum(tx_ring, skb, tx_flags, protocol))
 			tx_flags |= IXGBE_TX_FLAGS_CSUM;
 	}
 
@@ -6953,12 +6912,16 @@ netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb,
 		ixgbe_maybe_stop_tx(tx_ring, DESC_NEEDED);
 
 	} else {
-		dev_kfree_skb_any(skb);
 		tx_ring->tx_buffer_info[first].time_stamp = 0;
 		tx_ring->next_to_use = first;
+		goto out_drop;
 	}
 
 	return NETDEV_TX_OK;
+
+out_drop:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
 }
 
 static netdev_tx_t ixgbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev)