[PATCH 5.15.y 1/2] net: dsa: microchip: update tag_ksz masks for KSZ9477 family

[Sasha Levin <sashal@kernel.org>]

From: Pieter Van Trappen <pieter.van.trappen@cern.ch>

[ Upstream commit 3f464b193d40e49299dcd087b10cc3b77cbbea68 ]

Remove magic number 7 by introducing a GENMASK macro instead.
Remove magic number 0x80 by using the BIT macro instead.

Signed-off-by: Pieter Van Trappen <pieter.van.trappen@cern.ch>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20240909134301.75448-1-vtpieter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: ba54bce747fa ("net: dsa: microchip: linearize skb for tail-tagging switches")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/dsa/tag_ksz.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 6795dd0174996..922e5cd4d4f06 100644
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -104,8 +104,9 @@ MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795);
 
 #define KSZ9477_INGRESS_TAG_LEN		2
 #define KSZ9477_PTP_TAG_LEN		4
-#define KSZ9477_PTP_TAG_INDICATION	0x80
+#define KSZ9477_PTP_TAG_INDICATION	BIT(7)
 
+#define KSZ9477_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
 #define KSZ9477_TAIL_TAG_OVERRIDE	BIT(9)
 #define KSZ9477_TAIL_TAG_LOOKUP		BIT(10)
 
@@ -138,7 +139,7 @@ static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
 {
 	/* Tag decoding */
 	u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
-	unsigned int port = tag[0] & 7;
+	unsigned int port = tag[0] & KSZ9477_TAIL_TAG_EG_PORT_M;
 	unsigned int len = KSZ_EGRESS_TAG_LEN;
 
 	/* Extra 4-bytes PTP timestamp */
-- 
2.50.1