[PATCH RFC net-next 17/19] net: dsa: tag_qca: switch to bitfield helpers

[Alexander Lobakin]

Make code look cleaner and more readable by using bitfield macros.
Misc: fix several macro identation and phdr type in qca_tag_xmit().

Signed-off-by: Alexander Lobakin <alobakin@xxxxxxxx>
---
 net/dsa/tag_qca.c | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c
index e1c4dd04734a..8939abce36d7 100644
--- a/net/dsa/tag_qca.c
+++ b/net/dsa/tag_qca.c
@@ -3,15 +3,15 @@
  * Copyright (c) 2015, The Linux Foundation. All rights reserved.
  */
 
+#include <linux/bitfield.h>
 #include <linux/etherdevice.h>
 
 #include "dsa_priv.h"
 
-#define QCA_HDR_LEN	2
-#define QCA_HDR_VERSION	0x2
+#define QCA_HDR_LEN			2
+#define QCA_HDR_VERSION			0x2
 
-#define QCA_HDR_RECV_VERSION_MASK	GENMASK(15, 14)
-#define QCA_HDR_RECV_VERSION_S		14
+#define QCA_HDR_RECV_VERSION(tag)	FIELD_GET(GENMASK(15, 14), tag)
 #define QCA_HDR_RECV_PRIORITY_MASK	GENMASK(13, 11)
 #define QCA_HDR_RECV_PRIORITY_S		11
 #define QCA_HDR_RECV_TYPE_MASK		GENMASK(10, 6)
@@ -19,19 +19,20 @@
 #define QCA_HDR_RECV_FRAME_IS_TAGGED	BIT(3)
 #define QCA_HDR_RECV_SOURCE_PORT_MASK	GENMASK(2, 0)
 
-#define QCA_HDR_XMIT_VERSION_MASK	GENMASK(15, 14)
-#define QCA_HDR_XMIT_VERSION_S		14
+#define QCA_HDR_XMIT_VERSION		FIELD_PREP(GENMASK(15, 14), \
+						   QCA_HDR_VERSION)
 #define QCA_HDR_XMIT_PRIORITY_MASK	GENMASK(13, 11)
 #define QCA_HDR_XMIT_PRIORITY_S		11
 #define QCA_HDR_XMIT_CONTROL_MASK	GENMASK(10, 8)
 #define QCA_HDR_XMIT_CONTROL_S		8
 #define QCA_HDR_XMIT_FROM_CPU		BIT(7)
-#define QCA_HDR_XMIT_DP_BIT_MASK	GENMASK(6, 0)
+#define QCA_HDR_XMIT_DP(port)		FIELD_PREP(GENMASK(6, 0), BIT(port))
 
 static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
 {
-	struct dsa_port *dp = dsa_slave_to_port(dev);
-	u16 *phdr, hdr;
+	const struct dsa_port *dp = dsa_slave_to_port(dev);
+	__be16 *phdr;
+	u16 hdr;
 
 	if (skb_cow_head(skb, 0) < 0)
 		return NULL;
@@ -39,11 +40,11 @@ static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
 	skb_push(skb, QCA_HDR_LEN);
 
 	memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN);
-	phdr = (u16 *)(skb->data + 2 * ETH_ALEN);
+	phdr = (__be16 *)(skb->data + 2 * ETH_ALEN);
 
 	/* Set the version field, and set destination port information */
-	hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S |
-		QCA_HDR_XMIT_FROM_CPU | BIT(dp->index);
+	hdr = QCA_HDR_XMIT_VERSION | QCA_HDR_XMIT_FROM_CPU |
+	      QCA_HDR_XMIT_DP(dp->index);
 
 	*phdr = htons(hdr);
 
@@ -53,7 +54,6 @@ static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 				   struct packet_type *pt)
 {
-	u8 ver;
 	int port;
 	__be16 *phdr, hdr;
 
@@ -68,8 +68,7 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 	hdr = ntohs(*phdr);
 
 	/* Make sure the version is correct */
-	ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S;
-	if (unlikely(ver != QCA_HDR_VERSION))
+	if (unlikely(QCA_HDR_RECV_VERSION(hdr) != QCA_HDR_VERSION))
 		return NULL;
 
 	/* Remove QCA tag and recalculate checksum */
-- 
2.24.1