From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Bobby Eshleman <bobbyeshleman@meta.com>,
	Paolo Abeni <pabeni@redhat.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.18 533/641] eth: fbnic: set DMA_HINT_L4 for all flows
Date: Tue, 24 Feb 2026 17:24:19 -0800
Message-ID: <20260225012401.444916464@linuxfoundation.org>
In-Reply-To: <20260225012348.915798704@linuxfoundation.org>
References: <20260225012348.915798704@linuxfoundation.org>
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6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bobby Eshleman <bobbyeshleman@meta.com>

[ Upstream commit 0f30a31b55c4179fc55613a75ef41d496687d465 ]

fbnic always advertises ETHTOOL_TCP_DATA_SPLIT_ENABLED via ethtool
.get_ringparam. To enable proper splitting for all flow types, even for
IP/Ethernet flows, this patch sets DMA_HINT_L4 unconditionally for all
RSS and NFC flow steering rules. According to the spec, L4 falls back to
L3 if no valid L4 is found, and L3 falls back to L2 if no L3 is found.
This makes sure that the correct header boundary is used regardless of
traffic type. This is important for zero-copy use cases where we must
ensure that all ZC packets are split correctly.

Fixes: 2b30fc01a6c7 ("eth: fbnic: Add support for HDS configuration")
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260211-fbnic-tcp-hds-fixes-v1-3-55d050e6f606@meta.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c | 3 +++
 drivers/net/ethernet/meta/fbnic/fbnic_rpc.c     | 5 ++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index 95fac020eb93c..08aed4103323e 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -1142,6 +1142,9 @@ static int fbnic_set_cls_rule_ins(struct fbnic_net *fbn,
 		return -EINVAL;
 	}
 
+	dest |= FIELD_PREP(FBNIC_RPC_ACT_TBL0_DMA_HINT,
+			   FBNIC_RCD_HDR_AL_DMA_HINT_L4);
+
 	/* Write action table values */
 	act_tcam->dest = dest;
 	act_tcam->rss_en_mask = fbnic_flow_hash_2_rss_en_mask(fbn, hash_idx);
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_rpc.c b/drivers/net/ethernet/meta/fbnic/fbnic_rpc.c
index 7f31e890031c0..42a186db43ea9 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_rpc.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_rpc.c
@@ -338,9 +338,8 @@ void fbnic_rss_reinit(struct fbnic_dev *fbd, struct fbnic_net *fbn)
 		else if (tstamp_mask & (1u << flow_type))
 			dest |= FBNIC_RPC_ACT_TBL0_TS_ENA;
 
-		if (act1_value[flow_type] & FBNIC_RPC_TCAM_ACT1_L4_VALID)
-			dest |= FIELD_PREP(FBNIC_RPC_ACT_TBL0_DMA_HINT,
-					   FBNIC_RCD_HDR_AL_DMA_HINT_L4);
+		dest |= FIELD_PREP(FBNIC_RPC_ACT_TBL0_DMA_HINT,
+				   FBNIC_RCD_HDR_AL_DMA_HINT_L4);
 
 		rss_en_mask = fbnic_flow_hash_2_rss_en_mask(fbn, flow_type);
 
-- 
2.51.0