Re: [PATCH net-next v7 3/4] net: macb: Add ARP support to WOL

[claudiu beznea <claudiu.beznea@tuxon.dev>]

On 21.06.2024 07:57, Vineeth Karumanchi wrote:
> 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: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Tested-by: Claudiu Beznea <claudiu.beznea@tuxon.dev> # on SAMA7G5

> ---
>  drivers/net/ethernet/cadence/macb.h      |  1 +
>  drivers/net/ethernet/cadence/macb_main.c | 58 +++++++++++++-----------
>  2 files changed, 33 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
> index 50cd35ef21ad..122663ff7834 100644
> --- a/drivers/net/ethernet/cadence/macb.h
> +++ b/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;
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 4007b291526f..cecc3d6e630f 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/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;
> +	phylink_ethtool_get_wol(bp->phylink, wol);
> +	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);
>