[PATCH v2 net-next 0/4] be2net patch-set

[PATCH v2 net-next 0/4] be2net patch-set

[Sriharsha Basavapatna]

v1->v2 changes:
Patch 4: fixed minor nits pointed out by Sergei Shtylyov

Hi David,

This patch set contains a few code refactoring changes to make it easy to
support new TX WRB formats in future ASICs. Please consider applying it to
net-next tree.

Patch 1: Refactors chip specific code to setup tx wrb into a separate routine.
Patch 2: Refactors tx enqueue function to remove a bit of duplicate code and
	 improves wrb setup steps.
Patch 3: Minor refactoring in tx compl to limit CQE accesses to 1 routine.
Patch 4: Adds a few inline functions.

Sriharsha Basavapatna (4):
  be2net: Refactor wrb_fill_hdr() routine
  be2net: Refactor be_xmit_enqueue() routine
  be2net: Minor code cleanup in tx completion process
  be2net: Add a few inline functions to test TXQ conditions

 drivers/net/ethernet/emulex/benet/be.h      |  40 ++++
 drivers/net/ethernet/emulex/benet/be_main.c | 294 ++++++++++++++++++----------
 2 files changed, 231 insertions(+), 103 deletions(-)

-- 
2.2.0.65.g9abc44b

[PATCH v2 net-next 1/4] be2net: Refactor wrb_fill_hdr() routine

[Sriharsha Basavapatna]

The WRB header is setup by wrb_fill_hdr() routine. This routine currently
gets some of the WRB params as args and figures out rest of the WRB params
by looking at various fields in skb (like gso, checksum, vlan-tag etc).
All these params could instead be retrieved from the skb into a structure
and passed to this routine. This separates wrb_fill_hdr() to only provide
chip-specific code to fill the WRB. This also makes it simple to support
chips with different WRB formats.

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@emulex.com>
---
 drivers/net/ethernet/emulex/benet/be.h      |  33 +++++++++
 drivers/net/ethernet/emulex/benet/be_main.c | 105 +++++++++++++++++-----------
 2 files changed, 99 insertions(+), 39 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be.h b/drivers/net/ethernet/emulex/benet/be.h
index 27de37a..bc7f3d6 100644
--- a/drivers/net/ethernet/emulex/benet/be.h
+++ b/drivers/net/ethernet/emulex/benet/be.h
@@ -417,6 +417,39 @@ struct rss_info {
 	u8 rss_hkey[RSS_HASH_KEY_LEN];
 };
 
+/* Macros to read/write the 'features' word of be_wrb_params structure.
+ */
+#define	BE_WRB_F_BIT(name)			BE_WRB_F_##name##_BIT
+#define	BE_WRB_F_MASK(name)			BIT_MASK(BE_WRB_F_##name##_BIT)
+
+#define	BE_WRB_F_GET(word, name)	\
+	(((word) & (BE_WRB_F_MASK(name))) >> BE_WRB_F_BIT(name))
+
+#define	BE_WRB_F_SET(word, name, val)	\
+	((word) |= (((val) << BE_WRB_F_BIT(name)) & BE_WRB_F_MASK(name)))
+
+/* Feature/offload bits */
+enum {
+	BE_WRB_F_CRC_BIT,		/* Ethernet CRC */
+	BE_WRB_F_IPCS_BIT,		/* IP csum */
+	BE_WRB_F_TCPCS_BIT,		/* TCP csum */
+	BE_WRB_F_UDPCS_BIT,		/* UDP csum */
+	BE_WRB_F_LSO_BIT,		/* LSO */
+	BE_WRB_F_LSO6_BIT,		/* LSO6 */
+	BE_WRB_F_VLAN_BIT,		/* VLAN */
+	BE_WRB_F_VLAN_SKIP_HW_BIT	/* Skip VLAN tag (workaround) */
+};
+
+/* The structure below provides a HW-agnostic abstraction of WRB params
+ * retrieved from a TX skb. This is in turn passed to chip specific routines
+ * during transmit, to set the corresponding params in the WRB.
+ */
+struct be_wrb_params {
+	u32 features;	/* Feature bits */
+	u16 vlan_tag;	/* VLAN tag */
+	u16 lso_mss;	/* MSS for LSO */
+};
+
 struct be_adapter {
 	struct pci_dev *pdev;
 	struct net_device *netdev;
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index 932b93a..40f54c0 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -728,48 +728,71 @@ static u16 skb_ip_proto(struct sk_buff *skb)
 		ip_hdr(skb)->protocol : ipv6_hdr(skb)->nexthdr;
 }
 
-static void wrb_fill_hdr(struct be_adapter *adapter, struct be_eth_hdr_wrb *hdr,
-			 struct sk_buff *skb, u32 wrb_cnt, u32 len,
-			 bool skip_hw_vlan)
+static void be_get_wrb_params_from_skb(struct be_adapter *adapter,
+				       struct sk_buff *skb,
+				       struct be_wrb_params *wrb_params)
 {
-	u16 vlan_tag, proto;
-
-	memset(hdr, 0, sizeof(*hdr));
-
-	SET_TX_WRB_HDR_BITS(crc, hdr, 1);
+	u16 proto;
 
 	if (skb_is_gso(skb)) {
-		SET_TX_WRB_HDR_BITS(lso, hdr, 1);
-		SET_TX_WRB_HDR_BITS(lso_mss, hdr, skb_shinfo(skb)->gso_size);
+		BE_WRB_F_SET(wrb_params->features, LSO, 1);
+		wrb_params->lso_mss = skb_shinfo(skb)->gso_size;
 		if (skb_is_gso_v6(skb) && !lancer_chip(adapter))
-			SET_TX_WRB_HDR_BITS(lso6, hdr, 1);
+			BE_WRB_F_SET(wrb_params->features, LSO6, 1);
 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		if (skb->encapsulation) {
-			SET_TX_WRB_HDR_BITS(ipcs, hdr, 1);
+			BE_WRB_F_SET(wrb_params->features, IPCS, 1);
 			proto = skb_inner_ip_proto(skb);
 		} else {
 			proto = skb_ip_proto(skb);
 		}
 		if (proto == IPPROTO_TCP)
-			SET_TX_WRB_HDR_BITS(tcpcs, hdr, 1);
+			BE_WRB_F_SET(wrb_params->features, TCPCS, 1);
 		else if (proto == IPPROTO_UDP)
-			SET_TX_WRB_HDR_BITS(udpcs, hdr, 1);
+			BE_WRB_F_SET(wrb_params->features, UDPCS, 1);
 	}
 
 	if (skb_vlan_tag_present(skb)) {
-		SET_TX_WRB_HDR_BITS(vlan, hdr, 1);
-		vlan_tag = be_get_tx_vlan_tag(adapter, skb);
-		SET_TX_WRB_HDR_BITS(vlan_tag, hdr, vlan_tag);
+		BE_WRB_F_SET(wrb_params->features, VLAN, 1);
+		wrb_params->vlan_tag = be_get_tx_vlan_tag(adapter, skb);
 	}
 
-	SET_TX_WRB_HDR_BITS(num_wrb, hdr, wrb_cnt);
-	SET_TX_WRB_HDR_BITS(len, hdr, len);
+	BE_WRB_F_SET(wrb_params->features, CRC, 1);
+}
+
+static void wrb_fill_hdr(struct be_adapter *adapter,
+			 struct be_eth_hdr_wrb *hdr,
+			 struct be_wrb_params *wrb_params,
+			 struct sk_buff *skb)
+{
+	memset(hdr, 0, sizeof(*hdr));
 
-	/* Hack to skip HW VLAN tagging needs evt = 1, compl = 0
-	 * When this hack is not needed, the evt bit is set while ringing DB
+	SET_TX_WRB_HDR_BITS(crc, hdr,
+			    BE_WRB_F_GET(wrb_params->features, CRC));
+	SET_TX_WRB_HDR_BITS(ipcs, hdr,
+			    BE_WRB_F_GET(wrb_params->features, IPCS));
+	SET_TX_WRB_HDR_BITS(tcpcs, hdr,
+			    BE_WRB_F_GET(wrb_params->features, TCPCS));
+	SET_TX_WRB_HDR_BITS(udpcs, hdr,
+			    BE_WRB_F_GET(wrb_params->features, UDPCS));
+
+	SET_TX_WRB_HDR_BITS(lso, hdr,
+			    BE_WRB_F_GET(wrb_params->features, LSO));
+	SET_TX_WRB_HDR_BITS(lso6, hdr,
+			    BE_WRB_F_GET(wrb_params->features, LSO6));
+	SET_TX_WRB_HDR_BITS(lso_mss, hdr, wrb_params->lso_mss);
+
+	/* Hack to skip HW VLAN tagging needs evt = 1, compl = 0. When this
+	 * hack is not needed, the evt bit is set while ringing DB.
 	 */
-	if (skip_hw_vlan)
-		SET_TX_WRB_HDR_BITS(event, hdr, 1);
+	SET_TX_WRB_HDR_BITS(event, hdr,
+			    BE_WRB_F_GET(wrb_params->features, VLAN_SKIP_HW));
+	SET_TX_WRB_HDR_BITS(vlan, hdr,
+			    BE_WRB_F_GET(wrb_params->features, VLAN));
+	SET_TX_WRB_HDR_BITS(vlan_tag, hdr, wrb_params->vlan_tag);
+
+	SET_TX_WRB_HDR_BITS(num_wrb, hdr, skb_wrb_cnt(skb));
+	SET_TX_WRB_HDR_BITS(len, hdr, skb->len);
 }
 
 static void unmap_tx_frag(struct device *dev, struct be_eth_wrb *wrb,
@@ -791,7 +814,8 @@ static void unmap_tx_frag(struct device *dev, struct be_eth_wrb *wrb,
 
 /* Returns the number of WRBs used up by the skb */
 static u32 be_xmit_enqueue(struct be_adapter *adapter, struct be_tx_obj *txo,
-			   struct sk_buff *skb, bool skip_hw_vlan)
+			   struct sk_buff *skb,
+			   struct be_wrb_params *wrb_params)
 {
 	u32 i, copied = 0, wrb_cnt = skb_wrb_cnt(skb);
 	struct device *dev = &adapter->pdev->dev;
@@ -803,7 +827,7 @@ static u32 be_xmit_enqueue(struct be_adapter *adapter, struct be_tx_obj *txo,
 	u16 head = txq->head;
 
 	hdr = queue_head_node(txq);
-	wrb_fill_hdr(adapter, hdr, skb, wrb_cnt, skb->len, skip_hw_vlan);
+	wrb_fill_hdr(adapter, hdr, wrb_params, skb);
 	be_dws_cpu_to_le(hdr, sizeof(*hdr));
 
 	queue_head_inc(txq);
@@ -870,7 +894,8 @@ static inline int qnq_async_evt_rcvd(struct be_adapter *adapter)
 
 static struct sk_buff *be_insert_vlan_in_pkt(struct be_adapter *adapter,
 					     struct sk_buff *skb,
-					     bool *skip_hw_vlan)
+					     struct be_wrb_params
+					     *wrb_params)
 {
 	u16 vlan_tag = 0;
 
@@ -887,8 +912,7 @@ static struct sk_buff *be_insert_vlan_in_pkt(struct be_adapter *adapter,
 		/* f/w workaround to set skip_hw_vlan = 1, informs the F/W to
 		 * skip VLAN insertion
 		 */
-		if (skip_hw_vlan)
-			*skip_hw_vlan = true;
+		BE_WRB_F_SET(wrb_params->features, VLAN_SKIP_HW, 1);
 	}
 
 	if (vlan_tag) {
@@ -906,8 +930,7 @@ static struct sk_buff *be_insert_vlan_in_pkt(struct be_adapter *adapter,
 						vlan_tag);
 		if (unlikely(!skb))
 			return skb;
-		if (skip_hw_vlan)
-			*skip_hw_vlan = true;
+		BE_WRB_F_SET(wrb_params->features, VLAN_SKIP_HW, 1);
 	}
 
 	return skb;
@@ -947,7 +970,8 @@ static int be_ipv6_tx_stall_chk(struct be_adapter *adapter, struct sk_buff *skb)
 
 static struct sk_buff *be_lancer_xmit_workarounds(struct be_adapter *adapter,
 						  struct sk_buff *skb,
-						  bool *skip_hw_vlan)
+						  struct be_wrb_params
+						  *wrb_params)
 {
 	struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
 	unsigned int eth_hdr_len;
@@ -971,7 +995,7 @@ static struct sk_buff *be_lancer_xmit_workarounds(struct be_adapter *adapter,
 	 */
 	if (be_pvid_tagging_enabled(adapter) &&
 	    veh->h_vlan_proto == htons(ETH_P_8021Q))
-		*skip_hw_vlan = true;
+		BE_WRB_F_SET(wrb_params->features, VLAN_SKIP_HW, 1);
 
 	/* HW has a bug wherein it will calculate CSUM for VLAN
 	 * pkts even though it is disabled.
@@ -979,7 +1003,7 @@ static struct sk_buff *be_lancer_xmit_workarounds(struct be_adapter *adapter,
 	 */
 	if (skb->ip_summed != CHECKSUM_PARTIAL &&
 	    skb_vlan_tag_present(skb)) {
-		skb = be_insert_vlan_in_pkt(adapter, skb, skip_hw_vlan);
+		skb = be_insert_vlan_in_pkt(adapter, skb, wrb_params);
 		if (unlikely(!skb))
 			goto err;
 	}
@@ -1001,7 +1025,7 @@ static struct sk_buff *be_lancer_xmit_workarounds(struct be_adapter *adapter,
 	 */
 	if (be_ipv6_tx_stall_chk(adapter, skb) &&
 	    be_vlan_tag_tx_chk(adapter, skb)) {
-		skb = be_insert_vlan_in_pkt(adapter, skb, skip_hw_vlan);
+		skb = be_insert_vlan_in_pkt(adapter, skb, wrb_params);
 		if (unlikely(!skb))
 			goto err;
 	}
@@ -1015,7 +1039,7 @@ err:
 
 static struct sk_buff *be_xmit_workarounds(struct be_adapter *adapter,
 					   struct sk_buff *skb,
-					   bool *skip_hw_vlan)
+					   struct be_wrb_params *wrb_params)
 {
 	/* Lancer, SH-R ASICs have a bug wherein Packets that are 32 bytes or
 	 * less may cause a transmit stall on that port. So the work-around is
@@ -1027,7 +1051,7 @@ static struct sk_buff *be_xmit_workarounds(struct be_adapter *adapter,
 	}
 
 	if (BEx_chip(adapter) || lancer_chip(adapter)) {
-		skb = be_lancer_xmit_workarounds(adapter, skb, skip_hw_vlan);
+		skb = be_lancer_xmit_workarounds(adapter, skb, wrb_params);
 		if (!skb)
 			return NULL;
 	}
@@ -1061,18 +1085,21 @@ static void be_xmit_flush(struct be_adapter *adapter, struct be_tx_obj *txo)
 
 static netdev_tx_t be_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
-	bool skip_hw_vlan = false, flush = !skb->xmit_more;
 	struct be_adapter *adapter = netdev_priv(netdev);
 	u16 q_idx = skb_get_queue_mapping(skb);
 	struct be_tx_obj *txo = &adapter->tx_obj[q_idx];
+	struct be_wrb_params wrb_params = { 0 };
 	struct be_queue_info *txq = &txo->q;
+	bool flush = !skb->xmit_more;
 	u16 wrb_cnt;
 
-	skb = be_xmit_workarounds(adapter, skb, &skip_hw_vlan);
+	skb = be_xmit_workarounds(adapter, skb, &wrb_params);
 	if (unlikely(!skb))
 		goto drop;
 
-	wrb_cnt = be_xmit_enqueue(adapter, txo, skb, skip_hw_vlan);
+	be_get_wrb_params_from_skb(adapter, skb, &wrb_params);
+
+	wrb_cnt = be_xmit_enqueue(adapter, txo, skb, &wrb_params);
 	if (unlikely(!wrb_cnt)) {
 		dev_kfree_skb_any(skb);
 		goto drop;
-- 
2.2.0.65.g9abc44b

[PATCH v2 net-next 2/4] be2net: Refactor be_xmit_enqueue() routine

[Sriharsha Basavapatna]

- Reduce code duplication by moving WRB-frags setup into a function.
- Do not setup WRB-header before frags are setup, which is unncessary if
  there's errors while setting up frags. We should only grab an entry for
  the header, setup the frags and if everything is fine setup the header.
- The error cleanup can be moved into a small function.

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@emulex.com>
---
 drivers/net/ethernet/emulex/benet/be_main.c | 126 +++++++++++++++++++---------
 1 file changed, 86 insertions(+), 40 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index 40f54c0..2f17937 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -812,7 +812,80 @@ static void unmap_tx_frag(struct device *dev, struct be_eth_wrb *wrb,
 	}
 }
 
-/* Returns the number of WRBs used up by the skb */
+/* Grab a WRB header for xmit */
+static u16 be_tx_get_wrb_hdr(struct be_tx_obj *txo)
+{
+	u16 head = txo->q.head;
+
+	queue_head_inc(&txo->q);
+	return head;
+}
+
+/* Set up the WRB header for xmit */
+static void be_tx_setup_wrb_hdr(struct be_adapter *adapter,
+				struct be_tx_obj *txo,
+				struct be_wrb_params *wrb_params,
+				struct sk_buff *skb, u16 head)
+{
+	u32 num_frags = skb_wrb_cnt(skb);
+	struct be_queue_info *txq = &txo->q;
+	struct be_eth_hdr_wrb *hdr = queue_index_node(txq, head);
+
+	wrb_fill_hdr(adapter, hdr, wrb_params, skb);
+	be_dws_cpu_to_le(hdr, sizeof(*hdr));
+
+	BUG_ON(txo->sent_skb_list[head]);
+	txo->sent_skb_list[head] = skb;
+	txo->last_req_hdr = head;
+	atomic_add(num_frags, &txq->used);
+	txo->last_req_wrb_cnt = num_frags;
+	txo->pend_wrb_cnt += num_frags;
+}
+
+/* Setup a WRB fragment (buffer descriptor) for xmit */
+static void be_tx_setup_wrb_frag(struct be_tx_obj *txo, dma_addr_t busaddr,
+				 int len)
+{
+	struct be_eth_wrb *wrb;
+	struct be_queue_info *txq = &txo->q;
+
+	wrb = queue_head_node(txq);
+	wrb_fill(wrb, busaddr, len);
+	queue_head_inc(txq);
+}
+
+/* Bring the queue back to the state it was in before be_xmit_enqueue() routine
+ * was invoked. The producer index is restored to the previous packet and the
+ * WRBs of the current packet are unmapped. Invoked to handle tx setup errors.
+ */
+static void be_xmit_restore(struct be_adapter *adapter,
+			    struct be_tx_obj *txo, u16 head, bool map_single,
+			    u32 copied)
+{
+	struct device *dev;
+	struct be_eth_wrb *wrb;
+	struct be_queue_info *txq = &txo->q;
+
+	dev = &adapter->pdev->dev;
+	txq->head = head;
+
+	/* skip the first wrb (hdr); it's not mapped */
+	queue_head_inc(txq);
+	while (copied) {
+		wrb = queue_head_node(txq);
+		unmap_tx_frag(dev, wrb, map_single);
+		map_single = false;
+		copied -= le32_to_cpu(wrb->frag_len);
+		queue_head_inc(txq);
+	}
+
+	txq->head = head;
+}
+
+/* Enqueue the given packet for transmit. This routine allocates WRBs for the
+ * packet, dma maps the packet buffers and sets up the WRBs. Returns the number
+ * of WRBs used up by the packet.
+ */
 static u32 be_xmit_enqueue(struct be_adapter *adapter, struct be_tx_obj *txo,
 			   struct sk_buff *skb,
 			   struct be_wrb_params *wrb_params)
@@ -820,70 +893,43 @@ static u32 be_xmit_enqueue(struct be_adapter *adapter, struct be_tx_obj *txo,
 	u32 i, copied = 0, wrb_cnt = skb_wrb_cnt(skb);
 	struct device *dev = &adapter->pdev->dev;
 	struct be_queue_info *txq = &txo->q;
-	struct be_eth_hdr_wrb *hdr;
 	bool map_single = false;
-	struct be_eth_wrb *wrb;
-	dma_addr_t busaddr;
 	u16 head = txq->head;
+	dma_addr_t busaddr;
+	int len;
 
-	hdr = queue_head_node(txq);
-	wrb_fill_hdr(adapter, hdr, wrb_params, skb);
-	be_dws_cpu_to_le(hdr, sizeof(*hdr));
-
-	queue_head_inc(txq);
+	head = be_tx_get_wrb_hdr(txo);
 
 	if (skb->len > skb->data_len) {
-		int len = skb_headlen(skb);
+		len = skb_headlen(skb);
 
 		busaddr = dma_map_single(dev, skb->data, len, DMA_TO_DEVICE);
 		if (dma_mapping_error(dev, busaddr))
 			goto dma_err;
 		map_single = true;
-		wrb = queue_head_node(txq);
-		wrb_fill(wrb, busaddr, len);
-		queue_head_inc(txq);
+		be_tx_setup_wrb_frag(txo, busaddr, len);
 		copied += len;
 	}
 
 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 		const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i];
+		len = skb_frag_size(frag);
 
-		busaddr = skb_frag_dma_map(dev, frag, 0,
-					   skb_frag_size(frag), DMA_TO_DEVICE);
+		busaddr = skb_frag_dma_map(dev, frag, 0, len, DMA_TO_DEVICE);
 		if (dma_mapping_error(dev, busaddr))
 			goto dma_err;
-		wrb = queue_head_node(txq);
-		wrb_fill(wrb, busaddr, skb_frag_size(frag));
-		queue_head_inc(txq);
-		copied += skb_frag_size(frag);
+		be_tx_setup_wrb_frag(txo, busaddr, len);
+		copied += len;
 	}
 
-	BUG_ON(txo->sent_skb_list[head]);
-	txo->sent_skb_list[head] = skb;
-	txo->last_req_hdr = head;
-	atomic_add(wrb_cnt, &txq->used);
-	txo->last_req_wrb_cnt = wrb_cnt;
-	txo->pend_wrb_cnt += wrb_cnt;
+	be_tx_setup_wrb_hdr(adapter, txo, wrb_params, skb, head);
 
 	be_tx_stats_update(txo, skb);
 	return wrb_cnt;
 
 dma_err:
-	/* Bring the queue back to the state it was in before this
-	 * routine was invoked.
-	 */
-	txq->head = head;
-	/* skip the first wrb (hdr); it's not mapped */
-	queue_head_inc(txq);
-	while (copied) {
-		wrb = queue_head_node(txq);
-		unmap_tx_frag(dev, wrb, map_single);
-		map_single = false;
-		copied -= le32_to_cpu(wrb->frag_len);
-		adapter->drv_stats.dma_map_errors++;
-		queue_head_inc(txq);
-	}
-	txq->head = head;
+	adapter->drv_stats.dma_map_errors++;
+	be_xmit_restore(adapter, txo, head, map_single, copied);
 	return 0;
 }
 
-- 
2.2.0.65.g9abc44b

[PATCH v2 net-next 3/4] be2net: Minor code cleanup in tx completion process

[Sriharsha Basavapatna]

- To avoid multiple accesses to CQE, extract compl_status and end_idx from
  be_tx_compl_get().

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@emulex.com>
---
 drivers/net/ethernet/emulex/benet/be.h      |  7 +++++
 drivers/net/ethernet/emulex/benet/be_main.c | 47 +++++++++++++++--------------
 2 files changed, 31 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be.h b/drivers/net/ethernet/emulex/benet/be.h
index bc7f3d6..ad33bf1 100644
--- a/drivers/net/ethernet/emulex/benet/be.h
+++ b/drivers/net/ethernet/emulex/benet/be.h
@@ -238,10 +238,17 @@ struct be_tx_stats {
 	struct u64_stats_sync sync_compl;
 };
 
+/* Structure to hold some data of interest obtained from a TX CQE */
+struct be_tx_compl_info {
+	u8 status;		/* Completion status */
+	u16 end_index;		/* Completed TXQ Index */
+};
+
 struct be_tx_obj {
 	u32 db_offset;
 	struct be_queue_info q;
 	struct be_queue_info cq;
+	struct be_tx_compl_info txcp;
 	/* Remember the skbs that were transmitted */
 	struct sk_buff *sent_skb_list[TX_Q_LEN];
 	struct be_tx_stats stats;
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index 2f17937..b37b099 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -2065,18 +2065,23 @@ static void be_post_rx_frags(struct be_rx_obj *rxo, gfp_t gfp, u32 frags_needed)
 	}
 }
 
-static struct be_eth_tx_compl *be_tx_compl_get(struct be_queue_info *tx_cq)
+static struct be_tx_compl_info *be_tx_compl_get(struct be_tx_obj *txo)
 {
-	struct be_eth_tx_compl *txcp = queue_tail_node(tx_cq);
+	struct be_queue_info *tx_cq = &txo->cq;
+	struct be_tx_compl_info *txcp = &txo->txcp;
+	struct be_eth_tx_compl *compl = queue_tail_node(tx_cq);
 
-	if (txcp->dw[offsetof(struct amap_eth_tx_compl, valid) / 32] == 0)
+	if (compl->dw[offsetof(struct amap_eth_tx_compl, valid) / 32] == 0)
 		return NULL;
 
+	/* Ensure load ordering of valid bit dword and other dwords below */
 	rmb();
-	be_dws_le_to_cpu(txcp, sizeof(*txcp));
+	be_dws_le_to_cpu(compl, sizeof(*compl));
 
-	txcp->dw[offsetof(struct amap_eth_tx_compl, valid) / 32] = 0;
+	txcp->status = GET_TX_COMPL_BITS(status, compl);
+	txcp->end_index = GET_TX_COMPL_BITS(wrb_index, compl);
 
+	compl->dw[offsetof(struct amap_eth_tx_compl, valid) / 32] = 0;
 	queue_tail_inc(tx_cq);
 	return txcp;
 }
@@ -2197,9 +2202,9 @@ static void be_tx_compl_clean(struct be_adapter *adapter)
 {
 	u16 end_idx, notified_idx, cmpl = 0, timeo = 0, num_wrbs = 0;
 	struct device *dev = &adapter->pdev->dev;
-	struct be_tx_obj *txo;
+	struct be_tx_compl_info *txcp;
 	struct be_queue_info *txq;
-	struct be_eth_tx_compl *txcp;
+	struct be_tx_obj *txo;
 	int i, pending_txqs;
 
 	/* Stop polling for compls when HW has been silent for 10ms */
@@ -2210,10 +2215,10 @@ static void be_tx_compl_clean(struct be_adapter *adapter)
 			cmpl = 0;
 			num_wrbs = 0;
 			txq = &txo->q;
-			while ((txcp = be_tx_compl_get(&txo->cq))) {
-				end_idx = GET_TX_COMPL_BITS(wrb_index, txcp);
-				num_wrbs += be_tx_compl_process(adapter, txo,
-								end_idx);
+			while ((txcp = be_tx_compl_get(txo))) {
+				num_wrbs +=
+					be_tx_compl_process(adapter, txo,
+							    txcp->end_index);
 				cmpl++;
 			}
 			if (cmpl) {
@@ -2572,7 +2577,7 @@ loop_continue:
 	return work_done;
 }
 
-static inline void be_update_tx_err(struct be_tx_obj *txo, u32 status)
+static inline void be_update_tx_err(struct be_tx_obj *txo, u8 status)
 {
 	switch (status) {
 	case BE_TX_COMP_HDR_PARSE_ERR:
@@ -2587,7 +2592,7 @@ static inline void be_update_tx_err(struct be_tx_obj *txo, u32 status)
 	}
 }
 
-static inline void lancer_update_tx_err(struct be_tx_obj *txo, u32 status)
+static inline void lancer_update_tx_err(struct be_tx_obj *txo, u8 status)
 {
 	switch (status) {
 	case LANCER_TX_COMP_LSO_ERR:
@@ -2612,22 +2617,18 @@ static inline void lancer_update_tx_err(struct be_tx_obj *txo, u32 status)
 static void be_process_tx(struct be_adapter *adapter, struct be_tx_obj *txo,
 			  int idx)
 {
-	struct be_eth_tx_compl *txcp;
 	int num_wrbs = 0, work_done = 0;
-	u32 compl_status;
-	u16 last_idx;
+	struct be_tx_compl_info *txcp;
 
-	while ((txcp = be_tx_compl_get(&txo->cq))) {
-		last_idx = GET_TX_COMPL_BITS(wrb_index, txcp);
-		num_wrbs += be_tx_compl_process(adapter, txo, last_idx);
+	while ((txcp = be_tx_compl_get(txo))) {
+		num_wrbs += be_tx_compl_process(adapter, txo, txcp->end_index);
 		work_done++;
 
-		compl_status = GET_TX_COMPL_BITS(status, txcp);
-		if (compl_status) {
+		if (txcp->status) {
 			if (lancer_chip(adapter))
-				lancer_update_tx_err(txo, compl_status);
+				lancer_update_tx_err(txo, txcp->status);
 			else
-				be_update_tx_err(txo, compl_status);
+				be_update_tx_err(txo, txcp->status);
 		}
 	}
 
-- 
2.2.0.65.g9abc44b

[PATCH v2 net-next 4/4] be2net: Add a few inline functions to test TXQ conditions

[Sriharsha Basavapatna]

- Check qfull condition
- Check qwake condition
- Check pkts pending completion

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@emulex.com>
---
 drivers/net/ethernet/emulex/benet/be_main.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index b37b099..c58f2835 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -728,6 +728,21 @@ static u16 skb_ip_proto(struct sk_buff *skb)
 		ip_hdr(skb)->protocol : ipv6_hdr(skb)->nexthdr;
 }
 
+static inline bool be_is_txq_full(struct be_tx_obj *txo)
+{
+	return atomic_read(&txo->q.used) + BE_MAX_TX_FRAG_COUNT >= txo->q.len;
+}
+
+static inline bool be_can_txq_wake(struct be_tx_obj *txo)
+{
+	return atomic_read(&txo->q.used) < txo->q.len / 2;
+}
+
+static inline bool be_is_tx_compl_pending(struct be_tx_obj *txo)
+{
+	return atomic_read(&txo->q.used) > txo->pend_wrb_cnt;
+}
+
 static void be_get_wrb_params_from_skb(struct be_adapter *adapter,
 				       struct sk_buff *skb,
 				       struct be_wrb_params *wrb_params)
@@ -1135,7 +1150,6 @@ static netdev_tx_t be_xmit(struct sk_buff *skb, struct net_device *netdev)
 	u16 q_idx = skb_get_queue_mapping(skb);
 	struct be_tx_obj *txo = &adapter->tx_obj[q_idx];
 	struct be_wrb_params wrb_params = { 0 };
-	struct be_queue_info *txq = &txo->q;
 	bool flush = !skb->xmit_more;
 	u16 wrb_cnt;
 
@@ -1151,7 +1165,7 @@ static netdev_tx_t be_xmit(struct sk_buff *skb, struct net_device *netdev)
 		goto drop;
 	}
 
-	if ((atomic_read(&txq->used) + BE_MAX_TX_FRAG_COUNT) >= txq->len) {
+	if (be_is_txq_full(txo)) {
 		netif_stop_subqueue(netdev, q_idx);
 		tx_stats(txo)->tx_stops++;
 	}
@@ -2226,7 +2240,7 @@ static void be_tx_compl_clean(struct be_adapter *adapter)
 				atomic_sub(num_wrbs, &txq->used);
 				timeo = 0;
 			}
-			if (atomic_read(&txq->used) == txo->pend_wrb_cnt)
+			if (!be_is_tx_compl_pending(txo))
 				pending_txqs--;
 		}
 
@@ -2639,7 +2653,7 @@ static void be_process_tx(struct be_adapter *adapter, struct be_tx_obj *txo,
 		/* As Tx wrbs have been freed up, wake up netdev queue
 		 * if it was stopped due to lack of tx wrbs.  */
 		if (__netif_subqueue_stopped(adapter->netdev, idx) &&
-		    atomic_read(&txo->q.used) < txo->q.len / 2) {
+		    be_can_txq_wake(txo)) {
 			netif_wake_subqueue(adapter->netdev, idx);
 		}
 
-- 
2.2.0.65.g9abc44b

Re: [PATCH v2 net-next 0/4] be2net patch-set

[David Miller]

From: Sriharsha Basavapatna <sriharsha.basavapatna@emulex.com>
Date: Mon, 16 Feb 2015 08:03:44 +0530

> This patch set contains a few code refactoring changes to make it easy to
> support new TX WRB formats in future ASICs. Please consider applying it to
> net-next tree.
> 
> Patch 1: Refactors chip specific code to setup tx wrb into a separate routine.
> Patch 2: Refactors tx enqueue function to remove a bit of duplicate code and
> 	 improves wrb setup steps.
> Patch 3: Minor refactoring in tx compl to limit CQE accesses to 1 routine.
> Patch 4: Adds a few inline functions.

Series applied, thanks.