net: stmmac: Fallback to VLAN Perfect filtering if HASH is not available

If VLAN Hash Filtering is not available we can fallback to perfect
filtering instead. Let's implement this in XGMAC and GMAC cores and let
the user use this filter.

VLAN VID=0 always passes filter so we check if more than 2 VLANs are
created and return proper error code if so because perfect filtering
only supports 1 VID at a time.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 1 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index 5031398e612c..5cda360d5d07 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -555,7 +555,7 @@ static int dwxgmac2_rss_configure(struct mac_device_info *hw,
 }
 
 static void dwxgmac2_update_vlan_hash(struct mac_device_info *hw, u32 hash,
-				      bool is_double)
+				      u16 perfect_match, bool is_double)
 {
 	void __iomem *ioaddr = hw->pcsr;
 
@@ -576,6 +576,21 @@ static void dwxgmac2_update_vlan_hash(struct mac_device_info *hw, u32 hash,
 		}
 
 		writel(value, ioaddr + XGMAC_VLAN_TAG);
+	} else if (perfect_match) {
+		u32 value = readl(ioaddr + XGMAC_PACKET_FILTER);
+
+		value |= XGMAC_FILTER_VTFE;
+
+		writel(value, ioaddr + XGMAC_PACKET_FILTER);
+
+		value = XGMAC_VLAN_ETV;
+		if (is_double) {
+			value |= XGMAC_VLAN_EDVLP;
+			value |= XGMAC_VLAN_ESVL;
+			value |= XGMAC_VLAN_DOVLTC;
+		}
+
+		writel(value | perfect_match, ioaddr + XGMAC_VLAN_TAG);
 	} else {
 		u32 value = readl(ioaddr + XGMAC_PACKET_FILTER);