[PATCH net] bnge: skip dev_addr when building the VNIC unicast list

[Vikas Gupta <vikas.gupta@broadcom.com>]

The default VNIC programs the device's MAC as L2 filter 0 in
bnge_init_chip() via bnge_hwrm_set_vnic_filter(bn, 0, 0, dev_addr).
bnge_cfg_rx_mode() then walks dev->uc and programs each unicast
address as a further L2 filter, without excluding dev_addr.

Skip dev_addr when building uc_list, since it is already installed as
filter 0. As dev_addr now takes neither a uc_list slot nor an
l2_filters[] slot, count only the non-dev_addr entries for the
uc_list overflow check too, otherwise an input such as
{dev_addr, A, B, C} would needlessly fall back to promiscuous mode
even though A, B and C fit in exact-match filters.
bnge_uc_list_updated() applies the same skip and count so the
change detection stays consistent and does not loop.

This issue was caught by Sashiko (nipa).

Tested on Thor Ultra device.

Fixes: 9afad4a17174 ("bng_en: Configure default VNIC")
Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
Reviewed-by: Dharmender Garg <dharmender.garg@broadcom.com>
---
 .../net/ethernet/broadcom/bnge/bnge_netdev.c  | 28 +++++++++++++------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
index a4288f0258f8..92aea6f6f09f 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_netdev.c
@@ -2182,19 +2182,21 @@ static bool bnge_uc_list_updated(struct bnge_net *bn,
 				 const struct netdev_hw_addr_list *uc)
 {
 	struct bnge_vnic_info *vnic = &bn->vnic_info[BNGE_VNIC_DEFAULT];
+	struct net_device *dev = bn->netdev;
 	struct netdev_hw_addr *ha;
-	int off = 0;
-
-	if (netdev_hw_addr_list_count(uc) != (vnic->uc_filter_count - 1))
-		return true;
+	int off = 0, count = 0;
 
 	netdev_hw_addr_list_for_each(ha, uc) {
+		if (ether_addr_equal(ha->addr, dev->dev_addr))
+			continue;
+		if (count >= vnic->uc_filter_count - 1)
+			return true;
 		if (!ether_addr_equal(ha->addr, vnic->uc_list + off))
 			return true;
-
 		off += ETH_ALEN;
+		count++;
 	}
-	return false;
+	return count != vnic->uc_filter_count - 1;
 }
 
 static bool bnge_promisc_ok(struct bnge_net *bn)
@@ -2207,9 +2209,9 @@ static int bnge_cfg_rx_mode(struct bnge_net *bn, struct netdev_hw_addr_list *uc,
 {
 	struct bnge_vnic_info *vnic = &bn->vnic_info[BNGE_VNIC_DEFAULT];
 	struct net_device *dev = bn->netdev;
+	int i, off = 0, rc, uc_count = 0;
 	struct bnge_dev *bd = bn->bd;
 	struct netdev_hw_addr *ha;
-	int i, off = 0, rc;
 
 	if (!uc_update)
 		goto skip_uc;
@@ -2225,10 +2227,20 @@ static int bnge_cfg_rx_mode(struct bnge_net *bn, struct netdev_hw_addr_list *uc,
 
 	if (!snapshot)
 		netif_addr_lock_bh(dev);
-	if (netdev_hw_addr_list_count(uc) > (BNGE_MAX_UC_ADDRS - 1)) {
+	/* dev_addr is already programmed as L2 filter 0, so it takes neither a
+	 * uc_list slot nor an l2_filters[] slot. Count only the entries that
+	 * will actually be programmed so the overflow check matches the fill
+	 * loop below (and bnge_uc_list_updated()).
+	 */
+	netdev_hw_addr_list_for_each(ha, uc)
+		if (!ether_addr_equal(ha->addr, dev->dev_addr))
+			uc_count++;
+	if (uc_count > BNGE_MAX_UC_ADDRS - 1) {
 		vnic->rx_mask |= CFA_L2_SET_RX_MASK_REQ_MASK_PROMISCUOUS;
 	} else {
 		netdev_hw_addr_list_for_each(ha, uc) {
+			if (ether_addr_equal(ha->addr, dev->dev_addr))
+				continue;
 			memcpy(vnic->uc_list + off, ha->addr, ETH_ALEN);
 			off += ETH_ALEN;
 			vnic->uc_filter_count++;
-- 
2.52.0