netdevsim: Implement devlink rate leafs tx rate support

Implement new devlink ops that allow shared and max tx rate control for
devlink port rate objects (leafs) through devlink API.

Expose rate values of VF ports to netdevsim debugfs.
Co-developed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Dmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/netdevsim/dev.c

@@ -276,17 +276,26 @@ static void nsim_dev_debugfs_exit(struct nsim_dev *nsim_dev)
 static int nsim_dev_port_debugfs_init(struct nsim_dev *nsim_dev,
 				      struct nsim_dev_port *nsim_dev_port)
 {
+	struct nsim_bus_dev *nsim_bus_dev = nsim_dev->nsim_bus_dev;
+	unsigned int port_index = nsim_dev_port->port_index;
 	char port_ddir_name[16];
 	char dev_link_name[32];
 
-	sprintf(port_ddir_name, "%u", nsim_dev_port->port_index);
+	sprintf(port_ddir_name, "%u", port_index);
 	nsim_dev_port->ddir = debugfs_create_dir(port_ddir_name,
 						 nsim_dev->ports_ddir);
 	if (IS_ERR(nsim_dev_port->ddir))
 		return PTR_ERR(nsim_dev_port->ddir);
 
-	sprintf(dev_link_name, "../../../" DRV_NAME "%u",
-		nsim_dev->nsim_bus_dev->dev.id);
+	sprintf(dev_link_name, "../../../" DRV_NAME "%u", nsim_bus_dev->dev.id);
+	if (nsim_dev_port_is_vf(nsim_dev_port)) {
+		unsigned int vf_id = nsim_dev_port_index_to_vf_index(port_index);
+
+		debugfs_create_u16("tx_share", 0400, nsim_dev_port->ddir,
+				   &nsim_bus_dev->vfconfigs[vf_id].min_tx_rate);
+		debugfs_create_u16("tx_max", 0400, nsim_dev_port->ddir,
+				   &nsim_bus_dev->vfconfigs[vf_id].max_tx_rate);
+	}
 	debugfs_create_symlink("dev", nsim_dev_port->ddir, dev_link_name);
 
 	return 0;
@@ -990,6 +999,67 @@ nsim_dev_devlink_trap_policer_counter_get(struct devlink *devlink,
 	return 0;
 }
 
+#define NSIM_LINK_SPEED_MAX     5000 /* Mbps */
+#define NSIM_LINK_SPEED_UNIT    125000 /* 1 Mbps given in bytes/sec to avoid
+					* u64 overflow during conversion from
+					* bytes to bits.
+					*/
+
+static int nsim_rate_bytes_to_units(char *name, u64 *rate, struct netlink_ext_ack *extack)
+{
+	u64 val;
+	u32 rem;
+
+	val = div_u64_rem(*rate, NSIM_LINK_SPEED_UNIT, &rem);
+	if (rem) {
+		pr_err("%s rate value %lluBps not in link speed units of 1Mbps.\n",
+		       name, *rate);
+		NL_SET_ERR_MSG_MOD(extack, "TX rate value not in link speed units of 1Mbps.");
+		return -EINVAL;
+	}
+
+	if (val > NSIM_LINK_SPEED_MAX) {
+		pr_err("%s rate value %lluMbps exceed link maximum speed 5000Mbps.\n",
+		       name, val);
+		NL_SET_ERR_MSG_MOD(extack, "TX rate value exceed link maximum speed 5000Mbps.");
+		return -EINVAL;
+	}
+	*rate = val;
+	return 0;
+}
+
+static int nsim_leaf_tx_share_set(struct devlink_rate *devlink_rate, void *priv,
+				  u64 tx_share, struct netlink_ext_ack *extack)
+{
+	struct nsim_dev_port *nsim_dev_port = priv;
+	struct nsim_bus_dev *nsim_bus_dev = nsim_dev_port->ns->nsim_bus_dev;
+	int vf_id = nsim_dev_port_index_to_vf_index(nsim_dev_port->port_index);
+	int err;
+
+	err = nsim_rate_bytes_to_units("tx_share", &tx_share, extack);
+	if (err)
+		return err;
+
+	nsim_bus_dev->vfconfigs[vf_id].min_tx_rate = tx_share;
+	return 0;
+}
+
+static int nsim_leaf_tx_max_set(struct devlink_rate *devlink_rate, void *priv,
+				u64 tx_max, struct netlink_ext_ack *extack)
+{
+	struct nsim_dev_port *nsim_dev_port = priv;
+	struct nsim_bus_dev *nsim_bus_dev = nsim_dev_port->ns->nsim_bus_dev;
+	int vf_id = nsim_dev_port_index_to_vf_index(nsim_dev_port->port_index);
+	int err;
+
+	err = nsim_rate_bytes_to_units("tx_max", &tx_max, extack);
+	if (err)
+		return err;
+
+	nsim_bus_dev->vfconfigs[vf_id].max_tx_rate = tx_max;
+	return 0;
+}
+
 static const struct devlink_ops nsim_dev_devlink_ops = {
 	.eswitch_mode_set = nsim_devlink_eswitch_mode_set,
 	.eswitch_mode_get = nsim_devlink_eswitch_mode_get,
@@ -1005,6 +1075,8 @@ static const struct devlink_ops nsim_dev_devlink_ops = {
 	.trap_group_set = nsim_dev_devlink_trap_group_set,
 	.trap_policer_set = nsim_dev_devlink_trap_policer_set,
 	.trap_policer_counter_get = nsim_dev_devlink_trap_policer_counter_get,
+	.rate_leaf_tx_share_set = nsim_leaf_tx_share_set,
+	.rate_leaf_tx_max_set = nsim_leaf_tx_max_set,
 };
 
 #define NSIM_DEV_MAX_MACS_DEFAULT 32