[PATCH net-next v4 3/4] eth: bnxt: support RSS on IPv6 Flow Label

[Jakub Kicinski <kuba@kernel.org>]

It appears that the bnxt FW API has the relevant bit for Flow Label
hashing. Plumb in the support. Obey the capability bit.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
v4:
 - only set IP if tuple=2
v2: https://lore.kernel.org/20250724015101.186608-4-kuba@kernel.org
 - update the logic to pick the 2 tuple *OR* the FL bit
v1: https://lore.kernel.org/20250722014915.3365370-4-kuba@kernel.org

CC: michael.chan@broadcom.com
CC: pavan.chebbi@broadcom.com
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.h     |  1 +
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     |  2 ++
 .../net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 20 +++++++++++++++----
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index fda0d3cc6227..40ae34923511 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -2407,6 +2407,7 @@ struct bnxt {
 #define BNXT_RSS_CAP_ESP_V4_RSS_CAP		BIT(6)
 #define BNXT_RSS_CAP_ESP_V6_RSS_CAP		BIT(7)
 #define BNXT_RSS_CAP_MULTI_RSS_CTX		BIT(8)
+#define BNXT_RSS_CAP_IPV6_FLOW_LABEL_RSS_CAP	BIT(9)
 
 	u8			rss_hash_key[HW_HASH_KEY_SIZE];
 	u8			rss_hash_key_valid:1;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 5578ddcb465d..ab74c71c4557 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -6957,6 +6957,8 @@ static int bnxt_hwrm_vnic_qcaps(struct bnxt *bp)
 			bp->rss_cap |= BNXT_RSS_CAP_ESP_V4_RSS_CAP;
 		if (flags & VNIC_QCAPS_RESP_FLAGS_RSS_IPSEC_ESP_SPI_IPV6_CAP)
 			bp->rss_cap |= BNXT_RSS_CAP_ESP_V6_RSS_CAP;
+		if (flags & VNIC_QCAPS_RESP_FLAGS_RSS_IPV6_FLOW_LABEL_CAP)
+			bp->rss_cap |= BNXT_RSS_CAP_IPV6_FLOW_LABEL_RSS_CAP;
 		if (flags & VNIC_QCAPS_RESP_FLAGS_RE_FLUSH_CAP)
 			bp->fw_cap |= BNXT_FW_CAP_VNIC_RE_FLUSH;
 	}
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 1b37612b1c01..68a4ee9f69b1 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -1584,6 +1584,8 @@ static u64 get_ethtool_ipv6_rss(struct bnxt *bp)
 {
 	if (bp->rss_hash_cfg & VNIC_RSS_CFG_REQ_HASH_TYPE_IPV6)
 		return RXH_IP_SRC | RXH_IP_DST;
+	if (bp->rss_hash_cfg & VNIC_RSS_CFG_REQ_HASH_TYPE_IPV6_FLOW_LABEL)
+		return RXH_IP_SRC | RXH_IP_DST | RXH_IP6_FL;
 	return 0;
 }
 
@@ -1662,13 +1664,18 @@ static int bnxt_set_rxfh_fields(struct net_device *dev,
 
 	if (cmd->data == RXH_4TUPLE)
 		tuple = 4;
-	else if (cmd->data == RXH_2TUPLE)
+	else if (cmd->data == RXH_2TUPLE ||
+		 cmd->data == (RXH_2TUPLE | RXH_IP6_FL))
 		tuple = 2;
 	else if (!cmd->data)
 		tuple = 0;
 	else
 		return -EINVAL;
 
+	if (cmd->data & RXH_IP6_FL &&
+	    !(bp->rss_cap & BNXT_RSS_CAP_IPV6_FLOW_LABEL_RSS_CAP))
+		return -EINVAL;
+
 	if (cmd->flow_type == TCP_V4_FLOW) {
 		rss_hash_cfg &= ~VNIC_RSS_CFG_REQ_HASH_TYPE_TCP_IPV4;
 		if (tuple == 4)
@@ -1732,10 +1739,15 @@ static int bnxt_set_rxfh_fields(struct net_device *dev,
 	case AH_V6_FLOW:
 	case ESP_V6_FLOW:
 	case IPV6_FLOW:
-		if (tuple == 2)
+		rss_hash_cfg &= ~(VNIC_RSS_CFG_REQ_HASH_TYPE_IPV6 |
+				  VNIC_RSS_CFG_REQ_HASH_TYPE_IPV6_FLOW_LABEL);
+		if (!tuple)
+			break;
+		if (cmd->data & RXH_IP6_FL)
+			rss_hash_cfg |=
+				VNIC_RSS_CFG_REQ_HASH_TYPE_IPV6_FLOW_LABEL;
+		else if (tuple == 2)
 			rss_hash_cfg |= VNIC_RSS_CFG_REQ_HASH_TYPE_IPV6;
-		else if (!tuple)
-			rss_hash_cfg &= ~VNIC_RSS_CFG_REQ_HASH_TYPE_IPV6;
 		break;
 	}
 
-- 
2.50.1