net: dsa: mv88e6xxx: Export cross-chip PVT as devlink region

Export the raw PVT data in a devlink region so that it can be
inspected from userspace and compared to the current bridge
configuration.
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.h

@@ -23,6 +23,8 @@
 /* PVT limits for 4-bit port and 5-bit switch */
 #define MV88E6XXX_MAX_PVT_SWITCHES	32
 #define MV88E6XXX_MAX_PVT_PORTS		16
+#define MV88E6XXX_MAX_PVT_ENTRIES	\
+	(MV88E6XXX_MAX_PVT_SWITCHES * MV88E6XXX_MAX_PVT_PORTS)
 
 #define MV88E6XXX_MAX_GPIO	16
 
@@ -266,6 +268,7 @@ enum mv88e6xxx_region_id {
 	MV88E6XXX_REGION_GLOBAL2,
 	MV88E6XXX_REGION_ATU,
 	MV88E6XXX_REGION_VTU,
+	MV88E6XXX_REGION_PVT,
 
 	_MV88E6XXX_REGION_MAX,
 };

drivers/net/dsa/mv88e6xxx/devlink.c

@@ -503,6 +503,44 @@ static int mv88e6xxx_region_vtu_snapshot(struct devlink *dl,
 	return 0;
 }
 
+static int mv88e6xxx_region_pvt_snapshot(struct devlink *dl,
+					 const struct devlink_region_ops *ops,
+					 struct netlink_ext_ack *extack,
+					 u8 **data)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int dev, port, err;
+	u16 *pvt, *cur;
+
+	pvt = kcalloc(MV88E6XXX_MAX_PVT_ENTRIES, sizeof(*pvt), GFP_KERNEL);
+	if (!pvt)
+		return -ENOMEM;
+
+	mv88e6xxx_reg_lock(chip);
+
+	cur = pvt;
+	for (dev = 0; dev < MV88E6XXX_MAX_PVT_SWITCHES; dev++) {
+		for (port = 0; port < MV88E6XXX_MAX_PVT_PORTS; port++) {
+			err = mv88e6xxx_g2_pvt_read(chip, dev, port, cur);
+			if (err)
+				break;
+
+			cur++;
+		}
+	}
+
+	mv88e6xxx_reg_unlock(chip);
+
+	if (err) {
+		kfree(pvt);
+		return err;
+	}
+
+	*data = (u8 *)pvt;
+	return 0;
+}
+
 static int mv88e6xxx_region_port_snapshot(struct devlink_port *devlink_port,
 					  const struct devlink_port_region_ops *ops,
 					  struct netlink_ext_ack *extack,
@@ -567,6 +605,12 @@ static struct devlink_region_ops mv88e6xxx_region_vtu_ops = {
 	.destructor = kfree,
 };
 
+static struct devlink_region_ops mv88e6xxx_region_pvt_ops = {
+	.name = "pvt",
+	.snapshot = mv88e6xxx_region_pvt_snapshot,
+	.destructor = kfree,
+};
+
 static const struct devlink_port_region_ops mv88e6xxx_region_port_ops = {
 	.name = "port",
 	.snapshot = mv88e6xxx_region_port_snapshot,
@@ -576,6 +620,8 @@ static const struct devlink_port_region_ops mv88e6xxx_region_port_ops = {
 struct mv88e6xxx_region {
 	struct devlink_region_ops *ops;
 	u64 size;
+
+	bool (*cond)(struct mv88e6xxx_chip *chip);
 };
 
 static struct mv88e6xxx_region mv88e6xxx_regions[] = {
@@ -594,6 +640,11 @@ static struct mv88e6xxx_region mv88e6xxx_regions[] = {
 		.ops = &mv88e6xxx_region_vtu_ops
 	  /* calculated at runtime */
 	},
+	[MV88E6XXX_REGION_PVT] = {
+		.ops = &mv88e6xxx_region_pvt_ops,
+		.size = MV88E6XXX_MAX_PVT_ENTRIES * sizeof(u16),
+		.cond = mv88e6xxx_has_pvt,
+	},
 };
 
 static void
@@ -663,6 +714,7 @@ static int mv88e6xxx_setup_devlink_regions_ports(struct dsa_switch *ds,
 static int mv88e6xxx_setup_devlink_regions_global(struct dsa_switch *ds,
 						  struct mv88e6xxx_chip *chip)
 {
+	bool (*cond)(struct mv88e6xxx_chip *chip);
 	struct devlink_region_ops *ops;
 	struct devlink_region *region;
 	u64 size;
@@ -671,6 +723,10 @@ static int mv88e6xxx_setup_devlink_regions_global(struct dsa_switch *ds,
 	for (i = 0; i < ARRAY_SIZE(mv88e6xxx_regions); i++) {
 		ops = mv88e6xxx_regions[i].ops;
 		size = mv88e6xxx_regions[i].size;
+		cond = mv88e6xxx_regions[i].cond;
+
+		if (cond && !cond(chip))
+			continue;
 
 		switch (i) {
 		case MV88E6XXX_REGION_ATU:

drivers/net/dsa/mv88e6xxx/global2.c

@@ -239,6 +239,23 @@ static int mv88e6xxx_g2_pvt_op(struct mv88e6xxx_chip *chip, int src_dev,
 	return mv88e6xxx_g2_pvt_op_wait(chip);
 }
 
+int mv88e6xxx_g2_pvt_read(struct mv88e6xxx_chip *chip, int src_dev,
+			  int src_port, u16 *data)
+{
+	int err;
+
+	err = mv88e6xxx_g2_pvt_op_wait(chip);
+	if (err)
+		return err;
+
+	err = mv88e6xxx_g2_pvt_op(chip, src_dev, src_port,
+				  MV88E6XXX_G2_PVT_ADDR_OP_READ);
+	if (err)
+		return err;
+
+	return mv88e6xxx_g2_read(chip, MV88E6XXX_G2_PVT_DATA, data);
+}
+
 int mv88e6xxx_g2_pvt_write(struct mv88e6xxx_chip *chip, int src_dev,
 			   int src_port, u16 data)
 {

drivers/net/dsa/mv88e6xxx/global2.h

@@ -330,6 +330,8 @@ int mv88e6xxx_g2_get_eeprom16(struct mv88e6xxx_chip *chip,
 int mv88e6xxx_g2_set_eeprom16(struct mv88e6xxx_chip *chip,
 			      struct ethtool_eeprom *eeprom, u8 *data);
 
+int mv88e6xxx_g2_pvt_read(struct mv88e6xxx_chip *chip, int src_dev,
+			  int src_port, u16 *data);
 int mv88e6xxx_g2_pvt_write(struct mv88e6xxx_chip *chip, int src_dev,
 			   int src_port, u16 data);
 int mv88e6xxx_g2_misc_4_bit_port(struct mv88e6xxx_chip *chip);