Re: [PATCH v3 net-next 7/9] net: dsa: mv88e6xxx: Add devlink regions

On 9/9/2020 4:58 PM, Andrew Lunn wrote:

Allow the global registers, and the ATU to be snapshot via devlink
regions. It is later planned to add support for the port registers.

v2:
Remove left over debug prints
Comment ATU format is generic for mv88e6xxx, not wider

v3:
Make use of ops structure passed to snapshot function
Remove port regions

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---

[snip]

+static int mv88e6xxx_region_global_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;
+	u16 *registers;
+	int i, err;
+
+	registers = kmalloc_array(32, sizeof(u16), GFP_KERNEL);
+	if (!registers)
+		return -ENOMEM;
+
+	mv88e6xxx_reg_lock(chip);
+	for (i = 0; i < 32; i++) {
+		switch ((long)ops->priv) {
+		case 1:
+			err = mv88e6xxx_g1_read(chip, i, &registers[i]);
+			break;
+		case 2:
+			err = mv88e6xxx_g1_read(chip, i, &registers[i]);

Should this be mv88e6xxx_g2_read() here? Can you use the region IDs you 
defined above?

+			break;
+		default:
+			err = -EOPNOTSUPP;
+		}
+
+		if (err) {
+			kfree(registers);
+			goto out;
+		}
+	}
+	*data = (u8 *)registers;
+out:
+	mv88e6xxx_reg_unlock(chip);
+
+	return err;
+}
+
+/* The ATU entry varies between mv88e6xxx chipset generations. Define
+ * a generic format which covers all the current and hopefully future
+ * mv88e6xxx generations
+ */
+
+struct mv88e6xxx_devlink_atu_entry {
+	/* The FID is scattered over multiple registers. */
+	u16 fid;
+	u16 atu_op;
+	u16 atu_data;
+	u16 atu_01;
+	u16 atu_23;
+	u16 atu_45;
+};
+
+static int mv88e6xxx_region_atu_snapshot_fid(struct mv88e6xxx_chip *chip,
+					     int fid,
+					     struct mv88e6xxx_devlink_atu_entry *table,
+					     int *count)
+{
+	u16 atu_op, atu_data, atu_01, atu_23, atu_45;
+	struct mv88e6xxx_atu_entry addr;
+	int err;
+
+	addr.state = 0;
+	eth_broadcast_addr(addr.mac);
+
+	do {
+		err = mv88e6xxx_g1_atu_getnext(chip, fid, &addr);
+		if (err)
+			return err;
+
+		if (!addr.state)
+			break;
+
+		err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_ATU_OP, &atu_op);
+		if (err)
+			return err;
+
+		err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_ATU_DATA, &atu_data);
+		if (err)
+			return err;
+
+		err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_ATU_MAC01, &atu_01);
+		if (err)
+			return err;
+
+		err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_ATU_MAC23, &atu_23);
+		if (err)
+			return err;
+
+		err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_ATU_MAC45, &atu_45);
+		if (err)
+			return err;
+
+		table[*count].fid = fid;
+		table[*count].atu_op = atu_op;
+		table[*count].atu_data = atu_data;
+		table[*count].atu_01 = atu_01;
+		table[*count].atu_23 = atu_23;
+		table[*count].atu_45 = atu_45;

Can you refactor this to use a for/while loop?

+		(*count)++;
+	} while (!is_broadcast_ether_addr(addr.mac));
+
+	return 0;
+}
+
+static int mv88e6xxx_region_atu_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);
+	DECLARE_BITMAP(fid_bitmap, MV88E6XXX_N_FID);
+	struct mv88e6xxx_devlink_atu_entry *table;
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int fid = -1, count, err;
+
+	table = kmalloc_array(mv88e6xxx_num_databases(chip),
+			      sizeof(struct mv88e6xxx_devlink_atu_entry),
+			      GFP_KERNEL);
+	if (!table)
+		return -ENOMEM;
+
+	memset(table, 0, mv88e6xxx_num_databases(chip) *
+	       sizeof(struct mv88e6xxx_devlink_atu_entry));
+
+	count = 0;
+
+	mv88e6xxx_reg_lock(chip);
+
+	err = mv88e6xxx_fid_map(chip, fid_bitmap);
+	if (err)
+		goto out;
+
+	while (1) {
+		fid = find_next_bit(fid_bitmap, MV88E6XXX_N_FID, fid + 1);
+		if (fid == MV88E6XXX_N_FID)
+			break;
+
+		err =  mv88e6xxx_region_atu_snapshot_fid(chip, fid, table,
+							 &count);
+		if (err) {
+			kfree(table);
+			goto out;
+		}
+	}
+	*data = (u8 *)table;
+out:
+	mv88e6xxx_reg_unlock(chip);
+
+	return err;
+}
+
+static struct devlink_region_ops mv88e6xxx_region_global1_ops = {
+	.name = "global1",
+	.snapshot = mv88e6xxx_region_global_snapshot,
+	.destructor = kfree,
+	.priv = (void *)1,

Can you use the region IDs you defined?
-- 
Florian