net: macb: WoL support for GEM type of Ethernet controller

Adapt the Wake-on-Lan feature to the Cadence GEM Ethernet controller.
This controller has different register layout and cannot be handled by
previous code.
We disable completely interrupts on all the queues but the queue 0.
Handling of WoL interrupt is done in another interrupt handler
positioned depending on the controller version used, just between
suspend() and resume() calls.
It allows to lower pressure on the generic interrupt hot path by
removing the need to handle 2 tests for each IRQ: the first figuring out
the controller revision, the second for actually knowing if the WoL bit
is set.

Queue management in suspend()/resume() functions inspired from RFC patch
by Harini Katakam <harinik@xilinx.com>, thanks!

Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: Harini Katakam <harini.katakam@xilinx.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 126 insertions, 27 deletions

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index e5e37aa81b02..0f2417f09514 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -1517,6 +1517,35 @@ static void macb_tx_restart(struct macb_queue *queue)
 	macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART));
 }
 
+static irqreturn_t gem_wol_interrupt(int irq, void *dev_id)
+{
+	struct macb_queue *queue = dev_id;
+	struct macb *bp = queue->bp;
+	u32 status;
+
+	status = queue_readl(queue, ISR);
+
+	if (unlikely(!status))
+		return IRQ_NONE;
+
+	spin_lock(&bp->lock);
+
+	if (status & GEM_BIT(WOL)) {
+		queue_writel(queue, IDR, GEM_BIT(WOL));
+		gem_writel(bp, WOL, 0);
+		netdev_vdbg(bp->dev, "GEM WoL: queue = %u, isr = 0x%08lx\n",
+			    (unsigned int)(queue - bp->queues),
+			    (unsigned long)status);
+		if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
+			queue_writel(queue, ISR, GEM_BIT(WOL));
+		pm_wakeup_event(&bp->pdev->dev, 0);
+	}
+
+	spin_unlock(&bp->lock);
+
+	return IRQ_HANDLED;
+}
+
 static irqreturn_t macb_interrupt(int irq, void *dev_id)
 {
 	struct macb_queue *queue = dev_id;
@@ -3316,6 +3345,8 @@ static const struct ethtool_ops macb_ethtool_ops = {
 static const struct ethtool_ops gem_ethtool_ops = {
 	.get_regs_len		= macb_get_regs_len,
 	.get_regs		= macb_get_regs,
+	.get_wol		= macb_get_wol,
+	.set_wol		= macb_set_wol,
 	.get_link		= ethtool_op_get_link,
 	.get_ts_info		= macb_get_ts_info,
 	.get_ethtool_stats	= gem_get_ethtool_stats,
@@ -4567,33 +4598,68 @@ static int __maybe_unused macb_suspend(struct device *dev)
 	struct macb_queue *queue = bp->queues;
 	unsigned long flags;
 	unsigned int q;
+	int err;
 
 	if (!netif_running(netdev))
 		return 0;
 
 	if (bp->wol & MACB_WOL_ENABLED) {
-		macb_writel(bp, IER, MACB_BIT(WOL));
-		macb_writel(bp, WOL, MACB_BIT(MAG));
-		enable_irq_wake(bp->queues[0].irq);
-		netif_device_detach(netdev);
-	} else {
-		netif_device_detach(netdev);
+		spin_lock_irqsave(&bp->lock, flags);
+		/* Flush all status bits */
+		macb_writel(bp, TSR, -1);
+		macb_writel(bp, RSR, -1);
 		for (q = 0, queue = bp->queues; q < bp->num_queues;
-		     ++q, ++queue)
-			napi_disable(&queue->napi);
+		     ++q, ++queue) {
+			/* Disable all interrupts */
+			queue_writel(queue, IDR, -1);
+			queue_readl(queue, ISR);
+			if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
+				queue_writel(queue, ISR, -1);
+		}
+		/* Change interrupt handler and
+		 * Enable WoL IRQ on queue 0
+		 */
+		if (macb_is_gem(bp)) {
+			devm_free_irq(dev, bp->queues[0].irq, bp->queues);
+			err = devm_request_irq(dev, bp->queues[0].irq, gem_wol_interrupt,
+					       IRQF_SHARED, netdev->name, bp->queues);
+			if (err) {
+				dev_err(dev,
+					"Unable to request IRQ %d (error %d)\n",
+					bp->queues[0].irq, err);
+				spin_unlock_irqrestore(&bp->lock, flags);
+				return err;
+			}
+			queue_writel(bp->queues, IER, GEM_BIT(WOL));
+			gem_writel(bp, WOL, MACB_BIT(MAG));
+		} else {
+			queue_writel(bp->queues, IER, MACB_BIT(WOL));
+			macb_writel(bp, WOL, MACB_BIT(MAG));
+		}
+		spin_unlock_irqrestore(&bp->lock, flags);
+
+		enable_irq_wake(bp->queues[0].irq);
+	}
+
+	netif_device_detach(netdev);
+	for (q = 0, queue = bp->queues; q < bp->num_queues;
+	     ++q, ++queue)
+		napi_disable(&queue->napi);
+
+	if (!(bp->wol & MACB_WOL_ENABLED)) {
 		rtnl_lock();
 		phylink_stop(bp->phylink);
 		rtnl_unlock();
 		spin_lock_irqsave(&bp->lock, flags);
 		macb_reset_hw(bp);
 		spin_unlock_irqrestore(&bp->lock, flags);
+	}
 
-		if (!(bp->caps & MACB_CAPS_USRIO_DISABLED))
-			bp->pm_data.usrio = macb_or_gem_readl(bp, USRIO);
+	if (!(bp->caps & MACB_CAPS_USRIO_DISABLED))
+		bp->pm_data.usrio = macb_or_gem_readl(bp, USRIO);
 
-		if (netdev->hw_features & NETIF_F_NTUPLE)
-			bp->pm_data.scrt2 = gem_readl_n(bp, ETHT, SCRT2_ETHT);
-	}
+	if (netdev->hw_features & NETIF_F_NTUPLE)
+		bp->pm_data.scrt2 = gem_readl_n(bp, ETHT, SCRT2_ETHT);
 
 	if (bp->ptp_info)
 		bp->ptp_info->ptp_remove(netdev);
@@ -4608,7 +4674,9 @@ static int __maybe_unused macb_resume(struct device *dev)
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct macb *bp = netdev_priv(netdev);
 	struct macb_queue *queue = bp->queues;
+	unsigned long flags;
 	unsigned int q;
+	int err;
 
 	if (!netif_running(netdev))
 		return 0;
@@ -4617,29 +4685,60 @@ static int __maybe_unused macb_resume(struct device *dev)
 		pm_runtime_force_resume(dev);
 
 	if (bp->wol & MACB_WOL_ENABLED) {
-		macb_writel(bp, IDR, MACB_BIT(WOL));
-		macb_writel(bp, WOL, 0);
-		disable_irq_wake(bp->queues[0].irq);
-	} else {
-		macb_writel(bp, NCR, MACB_BIT(MPE));
-
-		if (netdev->hw_features & NETIF_F_NTUPLE)
-			gem_writel_n(bp, ETHT, SCRT2_ETHT, bp->pm_data.scrt2);
+		spin_lock_irqsave(&bp->lock, flags);
+		/* Disable WoL */
+		if (macb_is_gem(bp)) {
+			queue_writel(bp->queues, IDR, GEM_BIT(WOL));
+			gem_writel(bp, WOL, 0);
+		} else {
+			queue_writel(bp->queues, IDR, MACB_BIT(WOL));
+			macb_writel(bp, WOL, 0);
+		}
+		/* Clear ISR on queue 0 */
+		queue_readl(bp->queues, ISR);
+		if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
+			queue_writel(bp->queues, ISR, -1);
+		/* Replace interrupt handler on queue 0 */
+		devm_free_irq(dev, bp->queues[0].irq, bp->queues);
+		err = devm_request_irq(dev, bp->queues[0].irq, macb_interrupt,
+				       IRQF_SHARED, netdev->name, bp->queues);
+		if (err) {
+			dev_err(dev,
+				"Unable to request IRQ %d (error %d)\n",
+				bp->queues[0].irq, err);
+			spin_unlock_irqrestore(&bp->lock, flags);
+			return err;
+		}
+		spin_unlock_irqrestore(&bp->lock, flags);
 
-		if (!(bp->caps & MACB_CAPS_USRIO_DISABLED))
-			macb_or_gem_writel(bp, USRIO, bp->pm_data.usrio);
+		disable_irq_wake(bp->queues[0].irq);
 
-		for (q = 0, queue = bp->queues; q < bp->num_queues;
-		     ++q, ++queue)
-			napi_enable(&queue->napi);
+		/* Now make sure we disable phy before moving
+		 * to common restore path
+		 */
 		rtnl_lock();
-		phylink_start(bp->phylink);
+		phylink_stop(bp->phylink);
 		rtnl_unlock();
 	}
 
+	for (q = 0, queue = bp->queues; q < bp->num_queues;
+	     ++q, ++queue)
+		napi_enable(&queue->napi);
+
+	if (netdev->hw_features & NETIF_F_NTUPLE)
+		gem_writel_n(bp, ETHT, SCRT2_ETHT, bp->pm_data.scrt2);
+
+	if (!(bp->caps & MACB_CAPS_USRIO_DISABLED))
+		macb_or_gem_writel(bp, USRIO, bp->pm_data.usrio);
+
+	macb_writel(bp, NCR, MACB_BIT(MPE));
 	macb_init_hw(bp);
 	macb_set_rx_mode(netdev);
 	macb_restore_features(bp);
+	rtnl_lock();
+	phylink_start(bp->phylink);
+	rtnl_unlock();
+
 	netif_device_attach(netdev);
 	if (bp->ptp_info)
 		bp->ptp_info->ptp_init(netdev);