net: macb: Add ARP support to WOL

Extend wake-on LAN support with an ARP packet.

Currently, if PHY supports WOL, ethtool ignores the modes supported
by MACB. This change extends the WOL modes with MACB supported modes.

Advertise wake-on LAN supported modes by default without relying on
dt node. By default, wake-on LAN will be in disabled state.
Using ethtool, users can enable/disable or choose packet types.

For wake-on LAN via ARP, ensure the IP address is assigned and
report an error otherwise.
Co-developed-by: Harini Katakam <harini.katakam@amd.com>
Signed-off-by: Harini Katakam <harini.katakam@amd.com>
Signed-off-by: Vineeth Karumanchi <vineeth.karumanchi@amd.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Tested-by: Claudiu Beznea <claudiu.beznea@tuxon.dev> # on SAMA7G5
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/cadence/macb.h

@@ -1306,6 +1306,7 @@ struct macb {
 	unsigned int		jumbo_max_len;
 
 	u32			wol;
+	u32			wolopts;
 
 	/* holds value of rx watermark value for pbuf_rxcutthru register */
 	u32			rx_watermark;

drivers/net/ethernet/cadence/macb_main.c

@@ -38,6 +38,7 @@
 #include <linux/ptp_classify.h>
 #include <linux/reset.h>
 #include <linux/firmware/xlnx-zynqmp.h>
+#include <linux/inetdevice.h>
 #include "macb.h"
 
 /* This structure is only used for MACB on SiFive FU540 devices */
@@ -84,8 +85,7 @@ struct sifive_fu540_macb_mgmt {
 #define GEM_MTU_MIN_SIZE	ETH_MIN_MTU
 #define MACB_NETIF_LSO		NETIF_F_TSO
 
-#define MACB_WOL_HAS_MAGIC_PACKET	(0x1 << 0)
-#define MACB_WOL_ENABLED		(0x1 << 1)
+#define MACB_WOL_ENABLED		BIT(0)
 
 #define HS_SPEED_10000M			4
 #define MACB_SERDES_RATE_10G		1
@@ -3278,13 +3278,11 @@ static void macb_get_wol(struct net_device *netdev, struct ethtool_wolinfo *wol)
 {
 	struct macb *bp = netdev_priv(netdev);
 
-	if (bp->wol & MACB_WOL_HAS_MAGIC_PACKET) {
 	phylink_ethtool_get_wol(bp->phylink, wol);
-		wol->supported |= WAKE_MAGIC;
+	wol->supported |= (WAKE_MAGIC | WAKE_ARP);
 
-		if (bp->wol & MACB_WOL_ENABLED)
-			wol->wolopts |= WAKE_MAGIC;
-	}
+	/* Add macb wolopts to phy wolopts */
+	wol->wolopts |= bp->wolopts;
 }
 
 static int macb_set_wol(struct net_device *netdev, struct ethtool_wolinfo *wol)
@@ -3294,22 +3292,15 @@ static int macb_set_wol(struct net_device *netdev, struct ethtool_wolinfo *wol)
 
 	/* Pass the order to phylink layer */
 	ret = phylink_ethtool_set_wol(bp->phylink, wol);
-	/* Don't manage WoL on MAC if handled by the PHY
-	 * or if there's a failure in talking to the PHY
-	 */
-	if (!ret || ret != -EOPNOTSUPP)
+	/* Don't manage WoL on MAC, if PHY set_wol() fails */
+	if (ret && ret != -EOPNOTSUPP)
 		return ret;
 
-	if (!(bp->wol & MACB_WOL_HAS_MAGIC_PACKET) ||
-	    (wol->wolopts & ~WAKE_MAGIC))
-		return -EOPNOTSUPP;
-
-	if (wol->wolopts & WAKE_MAGIC)
-		bp->wol |= MACB_WOL_ENABLED;
-	else
-		bp->wol &= ~MACB_WOL_ENABLED;
+	bp->wolopts = (wol->wolopts & WAKE_MAGIC) ? WAKE_MAGIC : 0;
+	bp->wolopts |= (wol->wolopts & WAKE_ARP) ? WAKE_ARP : 0;
+	bp->wol = (wol->wolopts) ? MACB_WOL_ENABLED : 0;
 
-	device_set_wakeup_enable(&bp->pdev->dev, bp->wol & MACB_WOL_ENABLED);
+	device_set_wakeup_enable(&bp->pdev->dev, bp->wol);
 
 	return 0;
 }
@@ -5086,9 +5077,7 @@ static int macb_probe(struct platform_device *pdev)
 		bp->max_tx_length = GEM_MAX_TX_LEN;
 
 	bp->wol = 0;
-	if (of_property_read_bool(np, "magic-packet"))
-		bp->wol |= MACB_WOL_HAS_MAGIC_PACKET;
-	device_set_wakeup_capable(&pdev->dev, bp->wol & MACB_WOL_HAS_MAGIC_PACKET);
+	device_set_wakeup_capable(&pdev->dev, 1);
 
 	bp->usrio = macb_config->usrio;
 
@@ -5244,7 +5233,9 @@ static int __maybe_unused macb_suspend(struct device *dev)
 {
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct macb *bp = netdev_priv(netdev);
+	struct in_ifaddr *ifa = NULL;
 	struct macb_queue *queue;
+	struct in_device *idev;
 	unsigned long flags;
 	unsigned int q;
 	int err;
@@ -5257,6 +5248,14 @@ static int __maybe_unused macb_suspend(struct device *dev)
 		return 0;
 
 	if (bp->wol & MACB_WOL_ENABLED) {
+		/* Check for IP address in WOL ARP mode */
+		idev = __in_dev_get_rcu(bp->dev);
+		if (idev && idev->ifa_list)
+			ifa = rcu_access_pointer(idev->ifa_list);
+		if ((bp->wolopts & WAKE_ARP) && !ifa) {
+			netdev_err(netdev, "IP address not assigned as required by WoL walk ARP\n");
+			return -EOPNOTSUPP;
+		}
 		spin_lock_irqsave(&bp->lock, flags);
 
 		/* Disable Tx and Rx engines before  disabling the queues,
@@ -5290,6 +5289,13 @@ static int __maybe_unused macb_suspend(struct device *dev)
 		macb_writel(bp, TSR, -1);
 		macb_writel(bp, RSR, -1);
 
+		tmp = (bp->wolopts & WAKE_MAGIC) ? MACB_BIT(MAG) : 0;
+		if (bp->wolopts & WAKE_ARP) {
+			tmp |= MACB_BIT(ARP);
+			/* write IP address into register */
+			tmp |= MACB_BFEXT(IP, be32_to_cpu(ifa->ifa_local));
+		}
+
 		/* Change interrupt handler and
 		 * Enable WoL IRQ on queue 0
 		 */
@@ -5305,7 +5311,7 @@ static int __maybe_unused macb_suspend(struct device *dev)
 				return err;
 			}
 			queue_writel(bp->queues, IER, GEM_BIT(WOL));
-			gem_writel(bp, WOL, MACB_BIT(MAG));
+			gem_writel(bp, WOL, tmp);
 		} else {
 			err = devm_request_irq(dev, bp->queues[0].irq, macb_wol_interrupt,
 					       IRQF_SHARED, netdev->name, bp->queues);
@@ -5317,7 +5323,7 @@ static int __maybe_unused macb_suspend(struct device *dev)
 				return err;
 			}
 			queue_writel(bp->queues, IER, MACB_BIT(WOL));
-			macb_writel(bp, WOL, MACB_BIT(MAG));
+			macb_writel(bp, WOL, tmp);
 		}
 		spin_unlock_irqrestore(&bp->lock, flags);