From: Justin Chen <justinpopo6@gmail.com>
Date: Wed, 17 Jul 2019 14:58:53 -0700
Subject: net: bcmgenet: use promisc for unsupported filters
Git-commit: 35cbef9863640f06107144687bd13151bc2e8ce3
Patch-mainline: 5.3-rc1
References: networking-stable-19_07_25

Currently we silently ignore filters if we cannot meet the filter
requirements. This will lead to the MAC dropping packets that are
expected to pass. A better solution would be to set the NIC to promisc
mode when the required filters cannot be met.

Also correct the number of MDF filters supported. It should be 17,
not 16.

Signed-off-by: Justin Chen <justinpopo6@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c |   57 +++++++++++--------------
 1 file changed, 26 insertions(+), 31 deletions(-)

--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -3003,39 +3003,42 @@ static void bcmgenet_timeout(struct net_
 	netif_tx_wake_all_queues(dev);
 }
 
-#define MAX_MC_COUNT	16
+#define MAX_MDF_FILTER	17
 
 static inline void bcmgenet_set_mdf_addr(struct bcmgenet_priv *priv,
 					 unsigned char *addr,
-					 int *i,
-					 int *mc)
+					 int *i)
 {
-	u32 reg;
-
 	bcmgenet_umac_writel(priv, addr[0] << 8 | addr[1],
 			     UMAC_MDF_ADDR + (*i * 4));
 	bcmgenet_umac_writel(priv, addr[2] << 24 | addr[3] << 16 |
 			     addr[4] << 8 | addr[5],
 			     UMAC_MDF_ADDR + ((*i + 1) * 4));
-	reg = bcmgenet_umac_readl(priv, UMAC_MDF_CTRL);
-	reg |= (1 << (MAX_MC_COUNT - *mc));
-	bcmgenet_umac_writel(priv, reg, UMAC_MDF_CTRL);
 	*i += 2;
-	(*mc)++;
 }
 
 static void bcmgenet_set_rx_mode(struct net_device *dev)
 {
 	struct bcmgenet_priv *priv = netdev_priv(dev);
 	struct netdev_hw_addr *ha;
-	int i, mc;
+	int i, nfilter;
 	u32 reg;
 
 	netif_dbg(priv, hw, dev, "%s: %08X\n", __func__, dev->flags);
 
-	/* Promiscuous mode */
+	/* Number of filters needed */
+	nfilter = netdev_uc_count(dev) + netdev_mc_count(dev) + 2;
+
+	/*
+	 * Turn on promicuous mode for three scenarios
+	 * 1. IFF_PROMISC flag is set
+	 * 2. IFF_ALLMULTI flag is set
+	 * 3. The number of filters needed exceeds the number filters
+	 *    supported by the hardware.
+	*/
 	reg = bcmgenet_umac_readl(priv, UMAC_CMD);
-	if (dev->flags & IFF_PROMISC) {
+	if ((dev->flags & (IFF_PROMISC | IFF_ALLMULTI)) ||
+	    (nfilter > MAX_MDF_FILTER)) {
 		reg |= CMD_PROMISC;
 		bcmgenet_umac_writel(priv, reg, UMAC_CMD);
 		bcmgenet_umac_writel(priv, 0, UMAC_MDF_CTRL);
@@ -3045,32 +3048,24 @@ static void bcmgenet_set_rx_mode(struct
 		bcmgenet_umac_writel(priv, reg, UMAC_CMD);
 	}
 
-	/* UniMac doesn't support ALLMULTI */
-	if (dev->flags & IFF_ALLMULTI) {
-		netdev_warn(dev, "ALLMULTI is not supported\n");
-		return;
-	}
-
 	/* update MDF filter */
 	i = 0;
-	mc = 0;
 	/* Broadcast */
-	bcmgenet_set_mdf_addr(priv, dev->broadcast, &i, &mc);
+	bcmgenet_set_mdf_addr(priv, dev->broadcast, &i);
 	/* my own address.*/
-	bcmgenet_set_mdf_addr(priv, dev->dev_addr, &i, &mc);
-	/* Unicast list*/
-	if (netdev_uc_count(dev) > (MAX_MC_COUNT - mc))
-		return;
+	bcmgenet_set_mdf_addr(priv, dev->dev_addr, &i);
 
-	if (!netdev_uc_empty(dev))
-		netdev_for_each_uc_addr(ha, dev)
-			bcmgenet_set_mdf_addr(priv, ha->addr, &i, &mc);
-	/* Multicast */
-	if (netdev_mc_empty(dev) || netdev_mc_count(dev) >= (MAX_MC_COUNT - mc))
-		return;
+	/* Unicast */
+	netdev_for_each_uc_addr(ha, dev)
+		bcmgenet_set_mdf_addr(priv, ha->addr, &i);
 
+	/* Multicast */
 	netdev_for_each_mc_addr(ha, dev)
-		bcmgenet_set_mdf_addr(priv, ha->addr, &i, &mc);
+		bcmgenet_set_mdf_addr(priv, ha->addr, &i);
+
+	/* Enable filters */
+	reg = GENMASK(MAX_MDF_FILTER - 1, MAX_MDF_FILTER - nfilter);
+	bcmgenet_umac_writel(priv, reg, UMAC_MDF_CTRL);
 }
 
 /* Set the hardware MAC address. */