[PATCH net-next 4/4] atl1c: enable rx csum offload on Mikrotik 10/25G NIC

From: Gatis Peisenieks
Date: Mon Apr 19 2021 - 10:35:07 EST


Mikrotik 10/25G NIC supports hw checksum verification on rx for
IP/IPv6 + TCP/UDP packets. HW checksum offload helps reduce host
cpu load.

This enables the csum offload specifically for Mikrotik 10/25G NIC
as other HW supported by the driver is known to have problems with it.

TCP iperf3 to Threadripper 3960X with NIC improved 16.5 -> 20.0 Gbps
with mtu=1500.

Signed-off-by: Gatis Peisenieks <gatis@xxxxxxxxxxxx>
---
drivers/net/ethernet/atheros/atl1c/atl1c.h | 2 ++
drivers/net/ethernet/atheros/atl1c/atl1c_main.c | 5 +++++
2 files changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c.h b/drivers/net/ethernet/atheros/atl1c/atl1c.h
index 3fda7eb3bd69..9d70cb7544f1 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c.h
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c.h
@@ -241,6 +241,8 @@ struct atl1c_tpd_ext_desc {
#define RRS_PACKET_PROT_IS_IPV6_ONLY(word) \
((((word) >> RRS_PROT_ID_SHIFT) & RRS_PROT_ID_MASK) == 6)

+#define RRS_MT_PROT_ID_TCPUDP BIT(19)
+
struct atl1c_recv_ret_status {
__le32 word0;
__le32 rss_hash;
diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index 920e408ce7b4..9795657d6f58 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -1670,6 +1670,11 @@ static irqreturn_t atl1c_intr(int irq, void *data)
static inline void atl1c_rx_checksum(struct atl1c_adapter *adapter,
struct sk_buff *skb, struct atl1c_recv_ret_status *prrs)
{
+ if (adapter->hw.nic_type == athr_mt) {
+ if (prrs->word3 & RRS_MT_PROT_ID_TCPUDP)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ return;
+ }
/*
* The pid field in RRS in not correct sometimes, so we
* cannot figure out if the packet is fragmented or not,
--
2.31.1