[net-next PATCH v10 3/9] net: dsa: realtek: rtl8365mb: use dsa helpers for port iteration

[Luiz Angelo Daros de Luca]

Convert open-coded port iteration loops to use the DSA helpers and
restructure rtl8365mb_setup() into clear blocking, user, and
CPU port phases.

As part of this refactoring, unused ports are no longer initialized and
no longer receive a virtual IRQ mapping. To accommodate this, a guard
check is added to the interrupt handler (rtl8365mb_irq) to safely skip
ports without a valid IRQ mapping

Furthermore, since the new initialization loop starts with all ports
administratively isolated by default, CPU port forwarding and isolation
masks are explicitly configured at the end of the setup phase to prevent
egress traffic from being blocked.

Suggested-by: Abdulkader Alrezej <abdulkader.alrezej@xxxxxxxxx>
Reviewed-by: Linus Walleij <linusw@xxxxxxxxxx>
Reviewed-by: Mieczyslaw Nalewaj <namiltd@xxxxxxxxx>
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@xxxxxxxxx>
---
 drivers/net/dsa/realtek/rtl8365mb.c | 160 ++++++++++++++++++++++--------------
 1 file changed, 100 insertions(+), 60 deletions(-)

diff --git a/drivers/net/dsa/realtek/rtl8365mb.c b/drivers/net/dsa/realtek/rtl8365mb.c
index a1641378fcbb..fe7e0f0a66b7 100644
--- a/drivers/net/dsa/realtek/rtl8365mb.c
+++ b/drivers/net/dsa/realtek/rtl8365mb.c
@@ -1554,18 +1554,15 @@ static void rtl8365mb_stats_setup(struct realtek_priv *priv)
 {
 	struct rtl8365mb *mb = priv->chip_data;
 	struct dsa_switch *ds = &priv->ds;
-	int i;
+	struct dsa_port *dp;
 
 	/* Per-chip global mutex to protect MIB counter access, since doing
 	 * so requires accessing a series of registers in a particular order.
 	 */
 	mutex_init(&mb->mib_lock);
 
-	for (i = 0; i < priv->num_ports; i++) {
-		struct rtl8365mb_port *p = &mb->ports[i];
-
-		if (dsa_is_unused_port(ds, i))
-			continue;
+	dsa_switch_for_each_available_port(dp, ds) {
+		struct rtl8365mb_port *p = &mb->ports[dp->index];
 
 		/* Per-port spinlock to protect the stats64 data */
 		spin_lock_init(&p->stats_lock);
@@ -1581,13 +1578,10 @@ static void rtl8365mb_stats_teardown(struct realtek_priv *priv)
 {
 	struct rtl8365mb *mb = priv->chip_data;
 	struct dsa_switch *ds = &priv->ds;
-	int i;
-
-	for (i = 0; i < priv->num_ports; i++) {
-		struct rtl8365mb_port *p = &mb->ports[i];
+	struct dsa_port *dp;
 
-		if (dsa_is_unused_port(ds, i))
-			continue;
+	dsa_switch_for_each_available_port(dp, ds) {
+		struct rtl8365mb_port *p = &mb->ports[dp->index];
 
 		cancel_delayed_work_sync(&p->mib_work);
 	}
@@ -1646,6 +1640,9 @@ static irqreturn_t rtl8365mb_irq(int irq, void *data)
 	for_each_set_bit(line, &line_changes, priv->num_ports) {
 		int child_irq = irq_find_mapping(priv->irqdomain, line);
 
+		if (!child_irq)
+			continue;
+
 		handle_nested_irq(child_irq);
 	}
 
@@ -1709,13 +1706,14 @@ static int rtl8365mb_irq_disable(struct realtek_priv *priv)
 static int rtl8365mb_irq_setup(struct realtek_priv *priv)
 {
 	struct rtl8365mb *mb = priv->chip_data;
+	struct dsa_switch *ds = &priv->ds;
 	struct device_node *intc;
+	struct dsa_port *dp;
 	u32 irq_trig;
 	int virq;
 	int irq;
 	u32 val;
 	int ret;
-	int i;
 
 	intc = of_get_child_by_name(priv->dev->of_node, "interrupt-controller");
 	if (!intc) {
@@ -1744,8 +1742,8 @@ static int rtl8365mb_irq_setup(struct realtek_priv *priv)
 		goto out_put_node;
 	}
 
-	for (i = 0; i < priv->num_ports; i++) {
-		virq = irq_create_mapping(priv->irqdomain, i);
+	dsa_switch_for_each_available_port(dp, ds) {
+		virq = irq_create_mapping(priv->irqdomain, dp->index);
 		if (!virq) {
 			dev_err(priv->dev,
 				"failed to create irq domain mapping\n");
@@ -1815,9 +1813,11 @@ static int rtl8365mb_irq_setup(struct realtek_priv *priv)
 	mb->irq = 0;
 
 out_remove_irqdomain:
-	for (i = 0; i < priv->num_ports; i++) {
-		virq = irq_find_mapping(priv->irqdomain, i);
-		irq_dispose_mapping(virq);
+	dsa_switch_for_each_port(dp, ds) {
+		virq = irq_find_mapping(priv->irqdomain, dp->index);
+
+		if (virq)
+			irq_dispose_mapping(virq);
 	}
 
 	irq_domain_remove(priv->irqdomain);
@@ -1832,8 +1832,9 @@ static int rtl8365mb_irq_setup(struct realtek_priv *priv)
 static void rtl8365mb_irq_teardown(struct realtek_priv *priv)
 {
 	struct rtl8365mb *mb = priv->chip_data;
+	struct dsa_switch *ds = &priv->ds;
+	struct dsa_port *dp;
 	int virq;
-	int i;
 
 	if (mb->irq) {
 		free_irq(mb->irq, priv);
@@ -1841,9 +1842,15 @@ static void rtl8365mb_irq_teardown(struct realtek_priv *priv)
 	}
 
 	if (priv->irqdomain) {
-		for (i = 0; i < priv->num_ports; i++) {
-			virq = irq_find_mapping(priv->irqdomain, i);
-			irq_dispose_mapping(virq);
+		/* Unused ports with a linked PHY still have an active IRQ
+		 * mapping that must be disposed of during teardown. Loop
+		 * through all ports.
+		 */
+		dsa_switch_for_each_port(dp, ds) {
+			virq = irq_find_mapping(priv->irqdomain, dp->index);
+
+			if (virq)
+				irq_dispose_mapping(virq);
 		}
 
 		irq_domain_remove(priv->irqdomain);
@@ -1961,10 +1968,11 @@ static int rtl8365mb_setup(struct dsa_switch *ds)
 {
 	struct realtek_priv *priv = ds->priv;
 	struct rtl8365mb_cpu *cpu;
-	struct dsa_port *cpu_dp;
+	u32 downports_mask = 0;
+	u32 upports_mask = 0;
 	struct rtl8365mb *mb;
+	struct dsa_port *dp;
 	int ret;
-	int i;
 
 	mb = priv->chip_data;
 	cpu = &mb->cpu;
@@ -1991,33 +1999,11 @@ static int rtl8365mb_setup(struct dsa_switch *ds)
 	else if (ret)
 		dev_info(priv->dev, "no interrupt support\n");
 
-	/* Configure CPU tagging */
-	dsa_switch_for_each_cpu_port(cpu_dp, ds) {
-		cpu->mask |= BIT(cpu_dp->index);
-
-		if (cpu->trap_port == RTL8365MB_MAX_NUM_PORTS)
-			cpu->trap_port = cpu_dp->index;
-	}
-	cpu->enable = cpu->mask > 0;
+	/* Start with all ports blocked, including unused ports */
+	dsa_switch_for_each_port(dp, ds) {
+		struct rtl8365mb_port *p = &mb->ports[dp->index];
 
-	if (!cpu->enable) {
-		dev_err(priv->dev, "no upstream (CPU, Link) port defined\n");
-		ret = -EINVAL;
-		goto out_teardown_irq;
-	}
-
-	ret = rtl8365mb_cpu_config(priv);
-	if (ret)
-		goto out_teardown_irq;
-
-	/* Configure ports */
-	for (i = 0; i < priv->num_ports; i++) {
-		struct rtl8365mb_port *p = &mb->ports[i];
-
-		if (dsa_is_unused_port(ds, i))
-			continue;
-
-		if (dsa_is_dsa_port(ds, i)) {
+		if (dsa_port_is_dsa(dp)) {
 			/* Cascading (DSA links) is not supported yet.
 			 * Historically, the driver has always been broken
 			 * without a dedicated CPU port because CPU tagging
@@ -2029,27 +2015,81 @@ static int rtl8365mb_setup(struct dsa_switch *ds)
 			goto out_teardown_irq;
 		}
 
-		/* Forward only to the CPU */
-		ret = rtl8365mb_port_set_isolation(priv, i, cpu->mask);
+		/* Set the initial STP state of all ports to DISABLED, otherwise
+		 * ports will still forward frames to the CPU despite being
+		 * administratively down by default.
+		 */
+		rtl8365mb_port_stp_state_set(ds, dp->index, BR_STATE_DISABLED);
+
+		/* Start with all port completely isolated */
+		ret = rtl8365mb_port_set_isolation(priv, dp->index, 0);
 		if (ret)
 			goto out_teardown_irq;
 
 		/* Disable learning */
-		ret = rtl8365mb_port_set_learning(priv, i, false);
+		ret = rtl8365mb_port_set_learning(priv, dp->index, false);
 		if (ret)
 			goto out_teardown_irq;
 
-		/* Set the initial STP state of all ports to DISABLED, otherwise
-		 * ports will still forward frames to the CPU despite being
-		 * administratively down by default.
-		 */
-		rtl8365mb_port_stp_state_set(ds, i, BR_STATE_DISABLED);
-
 		/* Set up per-port private data */
 		p->priv = priv;
-		p->index = i;
+		p->index = dp->index;
+
+		/* Collect CPU ports. If we support cascade switches, it should
+		 * also include the upstream DSA ports.
+		 */
+		if (!dsa_port_is_cpu(dp))
+			continue;
+
+		upports_mask |= BIT(dp->index);
+	}
+
+	/* Configure user ports */
+	dsa_switch_for_each_port(dp, ds) {
+		if (!dsa_port_is_user(dp))
+			continue;
+
+		/* Forward only to the CPU */
+		ret = rtl8365mb_port_set_isolation(priv, dp->index,
+						   upports_mask);
+		if (ret)
+			goto out_teardown_irq;
+
+		/* If we support cascade switches, it should also include the
+		 * downstream DSA ports.
+		 */
+		downports_mask |= BIT(dp->index);
 	}
 
+	/* Configure CPU tagging */
+	/* If we support cascade switches, it should also include the upstream
+	 * DSA ports.
+	 */
+	dsa_switch_for_each_cpu_port(dp, ds) {
+		/* Use the first CPU port as trap_port */
+		if (cpu->trap_port == RTL8365MB_MAX_NUM_PORTS)
+			cpu->trap_port = dp->index;
+
+		/* Forward to all user ports */
+		ret = rtl8365mb_port_set_isolation(priv, dp->index,
+						   downports_mask);
+		if (ret)
+			goto out_teardown_irq;
+	}
+
+	cpu->mask = upports_mask;
+	cpu->enable = cpu->mask > 0;
+
+	if (!cpu->enable) {
+		dev_err(priv->dev, "no upstream (CPU, Link) port defined\n");
+		ret = -EINVAL;
+		goto out_teardown_irq;
+	}
+
+	ret = rtl8365mb_cpu_config(priv);
+	if (ret)
+		goto out_teardown_irq;
+
 	ret = rtl8365mb_port_change_mtu(ds, cpu->trap_port, ETH_DATA_LEN);
 	if (ret)
 		goto out_teardown_irq;

-- 
2.54.0