net: dsa: mv88e6xxx: Decode VTU problem interrupt

When there is a problem with the VTU, an interrupt can be
generated. Trap this interrupt and decode the registers to determine
what the problem was, then log the error.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -3980,11 +3980,15 @@ static int mv88e6xxx_probe(struct mdio_device *mdiodev)
 		err = mv88e6xxx_g1_atu_prob_irq_setup(chip);
 		if (err)
 			goto out_g2_irq;
+
+		err = mv88e6xxx_g1_vtu_prob_irq_setup(chip);
+		if (err)
+			goto out_g1_atu_prob_irq;
 	}
 
 	err = mv88e6xxx_mdios_register(chip, np);
 	if (err)
-		goto out_g1_atu_prob_irq;
+		goto out_g1_vtu_prob_irq;
 
 	err = mv88e6xxx_register_switch(chip);
 	if (err)
@@ -3994,6 +3998,8 @@ static int mv88e6xxx_probe(struct mdio_device *mdiodev)
 
 out_mdio:
 	mv88e6xxx_mdios_unregister(chip);
+out_g1_vtu_prob_irq:
+	mv88e6xxx_g1_vtu_prob_irq_free(chip);
 out_g1_atu_prob_irq:
 	mv88e6xxx_g1_atu_prob_irq_free(chip);
 out_g2_irq:
@@ -4019,6 +4025,7 @@ static void mv88e6xxx_remove(struct mdio_device *mdiodev)
 	mv88e6xxx_mdios_unregister(chip);
 
 	if (chip->irq > 0) {
+		mv88e6xxx_g1_vtu_prob_irq_free(chip);
 		mv88e6xxx_g1_atu_prob_irq_free(chip);
 		if (chip->info->g2_irqs > 0)
 			mv88e6xxx_g2_irq_free(chip);

drivers/net/dsa/mv88e6xxx/chip.h

@@ -208,6 +208,7 @@ struct mv88e6xxx_chip {
 	int device_irq;
 	int watchdog_irq;
 	int atu_prob_irq;
+	int vtu_prob_irq;
 };
 
 struct mv88e6xxx_bus_ops {

drivers/net/dsa/mv88e6xxx/global1.h

@@ -29,7 +29,7 @@
 #define MV88E6XXX_G1_STS_IRQ_AVB			8
 #define MV88E6XXX_G1_STS_IRQ_DEVICE			7
 #define MV88E6XXX_G1_STS_IRQ_STATS			6
-#define MV88E6XXX_G1_STS_IRQ_VTU_PROBLEM		5
+#define MV88E6XXX_G1_STS_IRQ_VTU_PROB			5
 #define MV88E6XXX_G1_STS_IRQ_VTU_DONE			4
 #define MV88E6XXX_G1_STS_IRQ_ATU_PROB			3
 #define MV88E6XXX_G1_STS_IRQ_ATU_DONE			2
@@ -82,6 +82,10 @@
 #define MV88E6XXX_G1_VTU_OP_VTU_GET_NEXT	0x4000
 #define MV88E6XXX_G1_VTU_OP_STU_LOAD_PURGE	0x5000
 #define MV88E6XXX_G1_VTU_OP_STU_GET_NEXT	0x6000
+#define MV88E6XXX_G1_VTU_OP_GET_CLR_VIOLATION	0x7000
+#define MV88E6XXX_G1_VTU_OP_MEMBER_VIOLATION	BIT(6)
+#define MV88E6XXX_G1_VTU_OP_MISS_VIOLATION	BIT(5)
+#define MV88E6XXX_G1_VTU_OP_SPID_MASK		0xf
 
 /* Offset 0x06: VTU VID Register */
 #define MV88E6XXX_G1_VTU_VID		0x06
@@ -275,5 +279,7 @@ int mv88e6390_g1_vtu_getnext(struct mv88e6xxx_chip *chip,
 int mv88e6390_g1_vtu_loadpurge(struct mv88e6xxx_chip *chip,
 			       struct mv88e6xxx_vtu_entry *entry);
 int mv88e6xxx_g1_vtu_flush(struct mv88e6xxx_chip *chip);
+int mv88e6xxx_g1_vtu_prob_irq_setup(struct mv88e6xxx_chip *chip);
+void mv88e6xxx_g1_vtu_prob_irq_free(struct mv88e6xxx_chip *chip);
 
 #endif /* _MV88E6XXX_GLOBAL1_H */

drivers/net/dsa/mv88e6xxx/global1_vtu.c

@@ -11,6 +11,9 @@
  * (at your option) any later version.
  */
 
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+
 #include "chip.h"
 #include "global1.h"
 
@@ -513,3 +516,74 @@ int mv88e6xxx_g1_vtu_flush(struct mv88e6xxx_chip *chip)
 
 	return mv88e6xxx_g1_vtu_op(chip, MV88E6XXX_G1_VTU_OP_FLUSH_ALL);
 }
+
+static irqreturn_t mv88e6xxx_g1_vtu_prob_irq_thread_fn(int irq, void *dev_id)
+{
+	struct mv88e6xxx_chip *chip = dev_id;
+	struct mv88e6xxx_vtu_entry entry;
+	int spid;
+	int err;
+	u16 val;
+
+	mutex_lock(&chip->reg_lock);
+
+	err = mv88e6xxx_g1_vtu_op(chip, MV88E6XXX_G1_VTU_OP_GET_CLR_VIOLATION);
+	if (err)
+		goto out;
+
+	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_VTU_OP, &val);
+	if (err)
+		goto out;
+
+	err = mv88e6xxx_g1_vtu_vid_read(chip, &entry);
+	if (err)
+		goto out;
+
+	mutex_unlock(&chip->reg_lock);
+
+	spid = val & MV88E6XXX_G1_VTU_OP_SPID_MASK;
+
+	if (val & MV88E6XXX_G1_VTU_OP_MEMBER_VIOLATION) {
+		dev_err_ratelimited(chip->dev, "VTU member violation for vid %d, source port %d\n",
+				    entry.vid, spid);
+	}
+
+	if (val & MV88E6XXX_G1_VTU_OP_MISS_VIOLATION)
+		dev_err_ratelimited(chip->dev, "VTU miss violation for vid %d, source port %d\n",
+				    entry.vid, spid);
+
+	return IRQ_HANDLED;
+
+out:
+	mutex_unlock(&chip->reg_lock);
+
+	dev_err(chip->dev, "VTU problem: error %d while handling interrupt\n",
+		err);
+
+	return IRQ_HANDLED;
+}
+
+int mv88e6xxx_g1_vtu_prob_irq_setup(struct mv88e6xxx_chip *chip)
+{
+	int err;
+
+	chip->vtu_prob_irq = irq_find_mapping(chip->g1_irq.domain,
+					      MV88E6XXX_G1_STS_IRQ_VTU_PROB);
+	if (chip->vtu_prob_irq < 0)
+		return chip->device_irq;
+
+	err = request_threaded_irq(chip->vtu_prob_irq, NULL,
+				   mv88e6xxx_g1_vtu_prob_irq_thread_fn,
+				   IRQF_ONESHOT, "mv88e6xxx-g1-vtu-prob",
+				   chip);
+	if (err)
+		irq_dispose_mapping(chip->vtu_prob_irq);
+
+	return err;
+}
+
+void mv88e6xxx_g1_vtu_prob_irq_free(struct mv88e6xxx_chip *chip)
+{
+	free_irq(chip->vtu_prob_irq, chip);
+	irq_dispose_mapping(chip->vtu_prob_irq);
+}