diff mbox series

[5.10.y-cip,06/11] net: ravb: Simplify types in RX csum validation

Message ID 20250227145720.229324-7-paul.barker.ct@bp.renesas.com (mailing list archive)
State New
Headers show
Series ravb backports: MTU fix, VLAN & IPv6 support | expand

Commit Message

Paul Barker Feb. 27, 2025, 2:57 p.m. UTC 
commit faacdbba01802c89f7043f9a47ad442c1195d307 upstream.

The hardware checksum value is used as a 16-bit flag, it is zero when
the checksum has been validated and non-zero otherwise. Therefore we
don't need to treat this as an actual __wsum type or call csum_unfold(),
we can just use a u16 pointer.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[Modified to apply to linux-5.10.y-cip which lacks skb fragment handling
 as we've chosen not to backport 966726324b7b ("net: ravb: Allocate RX
 buffers via page pool")]
Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
---
 drivers/net/ethernet/renesas/ravb_main.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 156e441fb308..9602e0b3a16c 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -711,11 +711,11 @@  static void ravb_get_tx_tstamp(struct net_device *ndev)
 
 static void ravb_rx_csum_gbeth(struct sk_buff *skb)
 {
-	__wsum csum_proto;
-	u8 *hw_csum;
+	size_t csum_len;
+	u16 *hw_csum;
 
-	/* The hardware checksum status is contained in sizeof(__sum16) * 2 = 4
-	 * bytes appended to packet data.
+	/* The hardware checksum status is contained in 4 bytes appended to
+	 * packet data.
 	 *
 	 * For ipv4, the first 2 bytes are the ip header checksum status. We can
 	 * ignore this as it will always be re-checked in inet_gro_receive().
@@ -723,15 +723,14 @@  static void ravb_rx_csum_gbeth(struct sk_buff *skb)
 	 * The last 2 bytes are the protocol checksum status which will be zero
 	 * if the checksum has been validated.
 	 */
-	if (unlikely(skb->len < sizeof(__sum16) * 2))
+	csum_len = sizeof(*hw_csum) * 2;
+	if (unlikely(skb->len < csum_len))
 		return;
 
-	hw_csum = skb_tail_pointer(skb) - sizeof(__sum16);
-	csum_proto = csum_unfold((__force __sum16)get_unaligned_le16(hw_csum));
-
-	skb_trim(skb, skb->len - 2 * sizeof(__sum16));
+	hw_csum = (u16 *)skb_tail_pointer(skb);
+	skb_trim(skb, skb->len - csum_len);
 
-	if (!csum_proto)
+	if (!get_unaligned(--hw_csum))
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 }