[PATCH v4 net-next 1/5] net: enetc: add Rx checksum offload for i.MX95 ENETC

[Wei Fang <wei.fang@nxp.com>]

ENETC rev 4.1 supports TCP and UDP checksum offload for receive, the bit
108 of the Rx BD will be set if the TCP/UDP checksum is correct. Since
this capability is not defined in register, the rx_csum bit is added to
struct enetc_drvdata to indicate whether the device supports Rx checksum
offload.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
---
v2: no changes
v3: no changes
v4: no changes
---
 drivers/net/ethernet/freescale/enetc/enetc.c       | 14 ++++++++++----
 drivers/net/ethernet/freescale/enetc/enetc.h       |  2 ++
 drivers/net/ethernet/freescale/enetc/enetc_hw.h    |  2 ++
 .../net/ethernet/freescale/enetc/enetc_pf_common.c |  3 +++
 4 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 35634c516e26..3137b6ee62d3 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -1011,10 +1011,15 @@ static void enetc_get_offloads(struct enetc_bdr *rx_ring,
 
 	/* TODO: hashing */
 	if (rx_ring->ndev->features & NETIF_F_RXCSUM) {
-		u16 inet_csum = le16_to_cpu(rxbd->r.inet_csum);
-
-		skb->csum = csum_unfold((__force __sum16)~htons(inet_csum));
-		skb->ip_summed = CHECKSUM_COMPLETE;
+		if (priv->active_offloads & ENETC_F_RXCSUM &&
+		    le16_to_cpu(rxbd->r.flags) & ENETC_RXBD_FLAG_L4_CSUM_OK) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		} else {
+			u16 inet_csum = le16_to_cpu(rxbd->r.inet_csum);
+
+			skb->csum = csum_unfold((__force __sum16)~htons(inet_csum));
+			skb->ip_summed = CHECKSUM_COMPLETE;
+		}
 	}
 
 	if (le16_to_cpu(rxbd->r.flags) & ENETC_RXBD_FLAG_VLAN) {
@@ -3281,6 +3286,7 @@ static const struct enetc_drvdata enetc_pf_data = {
 static const struct enetc_drvdata enetc4_pf_data = {
 	.sysclk_freq = ENETC_CLK_333M,
 	.pmac_offset = ENETC4_PMAC_OFFSET,
+	.rx_csum = 1,
 	.eth_ops = &enetc4_pf_ethtool_ops,
 };
 
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 72fa03dbc2dd..5b65f79e05be 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -234,6 +234,7 @@ enum enetc_errata {
 
 struct enetc_drvdata {
 	u32 pmac_offset; /* Only valid for PSI which supports 802.1Qbu */
+	u8 rx_csum:1;
 	u64 sysclk_freq;
 	const struct ethtool_ops *eth_ops;
 };
@@ -341,6 +342,7 @@ enum enetc_active_offloads {
 	ENETC_F_QBV			= BIT(9),
 	ENETC_F_QCI			= BIT(10),
 	ENETC_F_QBU			= BIT(11),
+	ENETC_F_RXCSUM			= BIT(12),
 };
 
 enum enetc_flags_bit {
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index 7c3285584f8a..4b8fd1879005 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -645,6 +645,8 @@ union enetc_rx_bd {
 #define ENETC_RXBD_LSTATUS(flags)	((flags) << 16)
 #define ENETC_RXBD_FLAG_VLAN	BIT(9)
 #define ENETC_RXBD_FLAG_TSTMP	BIT(10)
+/* UDP and TCP checksum offload, for ENETC 4.1 and later */
+#define ENETC_RXBD_FLAG_L4_CSUM_OK	BIT(12)
 #define ENETC_RXBD_FLAG_TPID	GENMASK(1, 0)
 
 #define ENETC_MAC_ADDR_FILT_CNT	8 /* # of supported entries per port */
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf_common.c b/drivers/net/ethernet/freescale/enetc/enetc_pf_common.c
index 0eecfc833164..91e79582a541 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf_common.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf_common.c
@@ -119,6 +119,9 @@ void enetc_pf_netdev_setup(struct enetc_si *si, struct net_device *ndev,
 
 	ndev->priv_flags |= IFF_UNICAST_FLT;
 
+	if (si->drvdata->rx_csum)
+		priv->active_offloads |= ENETC_F_RXCSUM;
+
 	/* TODO: currently, i.MX95 ENETC driver does not support advanced features */
 	if (!is_enetc_rev1(si)) {
 		ndev->hw_features &= ~(NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_LOOPBACK);
-- 
2.34.1