selftest: netdevsim: Add devlink rate tc-bw test

Test verifies that netdevsim correctly implements devlink ops callbacks
that set tc-bw on leaf or node rate object.

Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Link: https://patch.msgid.link/20250629142138.361537-4-mbloch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/netdevsim/dev.c

@@ -388,6 +388,17 @@ static const struct file_operations nsim_dev_rate_parent_fops = {
 	.owner = THIS_MODULE,
 };
 
+static void nsim_dev_tc_bw_debugfs_init(struct dentry *ddir, u32 *tc_bw)
+{
+	int i;
+
+	for (i = 0; i < DEVLINK_RATE_TCS_MAX; i++) {
+		char name[16];
+
+		snprintf(name, sizeof(name), "tc%d_bw", i);
+		debugfs_create_u32(name, 0400, ddir, &tc_bw[i]);
+	}
+}
 static int nsim_dev_port_debugfs_init(struct nsim_dev *nsim_dev,
 				      struct nsim_dev_port *nsim_dev_port)
 {
@@ -415,6 +426,8 @@ static int nsim_dev_port_debugfs_init(struct nsim_dev *nsim_dev,
 								 nsim_dev_port->ddir,
 								 &nsim_dev_port->parent_name,
 								 &nsim_dev_rate_parent_fops);
+		nsim_dev_tc_bw_debugfs_init(nsim_dev_port->ddir,
+					    nsim_dev_port->tc_bw);
 	}
 	debugfs_create_symlink("dev", nsim_dev_port->ddir, dev_link_name);
 
@@ -1172,6 +1185,19 @@ static int nsim_rate_bytes_to_units(char *name, u64 *rate, struct netlink_ext_ac
 	return 0;
 }
 
+static int nsim_leaf_tc_bw_set(struct devlink_rate *devlink_rate,
+			       void *priv, u32 *tc_bw,
+			       struct netlink_ext_ack *extack)
+{
+	struct nsim_dev_port *nsim_dev_port = priv;
+	int i;
+
+	for (i = 0; i < DEVLINK_RATE_TCS_MAX; i++)
+		nsim_dev_port->tc_bw[i] = tc_bw[i];
+
+	return 0;
+}
+
 static int nsim_leaf_tx_share_set(struct devlink_rate *devlink_rate, void *priv,
 				  u64 tx_share, struct netlink_ext_ack *extack)
 {
@@ -1210,8 +1236,21 @@ struct nsim_rate_node {
 	char *parent_name;
 	u16 tx_share;
 	u16 tx_max;
+	u32 tc_bw[DEVLINK_RATE_TCS_MAX];
 };
 
+static int nsim_node_tc_bw_set(struct devlink_rate *devlink_rate, void *priv,
+			       u32 *tc_bw, struct netlink_ext_ack *extack)
+{
+	struct nsim_rate_node *nsim_node = priv;
+	int i;
+
+	for (i = 0; i < DEVLINK_RATE_TCS_MAX; i++)
+		nsim_node->tc_bw[i] = tc_bw[i];
+
+	return 0;
+}
+
 static int nsim_node_tx_share_set(struct devlink_rate *devlink_rate, void *priv,
 				  u64 tx_share, struct netlink_ext_ack *extack)
 {
@@ -1264,6 +1303,8 @@ static int nsim_rate_node_new(struct devlink_rate *node, void **priv,
 						     &nsim_node->parent_name,
 						     &nsim_dev_rate_parent_fops);
 
+	nsim_dev_tc_bw_debugfs_init(nsim_node->ddir, nsim_node->tc_bw);
+
 	*priv = nsim_node;
 	return 0;
 }
@@ -1340,8 +1381,10 @@ static const struct devlink_ops nsim_dev_devlink_ops = {
 	.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,
+	.rate_leaf_tc_bw_set = nsim_leaf_tc_bw_set,
 	.rate_node_tx_share_set = nsim_node_tx_share_set,
 	.rate_node_tx_max_set = nsim_node_tx_max_set,
+	.rate_node_tc_bw_set = nsim_node_tc_bw_set,
 	.rate_node_new = nsim_rate_node_new,
 	.rate_node_del = nsim_rate_node_del,
 	.rate_leaf_parent_set = nsim_rate_leaf_parent_set,

drivers/net/netdevsim/netdevsim.h

@@ -276,6 +276,7 @@ struct nsim_dev_port {
 	struct dentry *ddir;
 	struct dentry *rate_parent;
 	char *parent_name;
+	u32 tc_bw[DEVLINK_RATE_TCS_MAX];
 	struct netdevsim *ns;
 };
 

tools/testing/selftests/drivers/net/netdevsim/devlink.sh

@@ -608,6 +608,46 @@ rate_attr_parent_check()
 	check_err $? "Unexpected parent attr value $api_value != $parent"
 }
 
+rate_attr_tc_bw_check()
+{
+	local handle=$1
+	local tc_bw=$2
+	local debug_file=$3
+
+	local tc_bw_str=""
+	for bw in $tc_bw; do
+		local tc=${bw%%:*}
+		local value=${bw##*:}
+		tc_bw_str="$tc_bw_str $tc:$value"
+	done
+	tc_bw_str=${tc_bw_str# }
+
+	rate_attr_set "$handle" tc-bw "$tc_bw_str"
+	check_err $? "Failed to set tc-bw values"
+
+	for bw in $tc_bw; do
+		local tc=${bw%%:*}
+		local value=${bw##*:}
+		local debug_value
+		debug_value=$(cat "$debug_file"/tc"${tc}"_bw)
+		check_err $? "Failed to read tc-bw value from debugfs for tc$tc"
+		[ "$debug_value" == "$value" ]
+		check_err $? "Unexpected tc-bw debug value for tc$tc: $debug_value != $value"
+	done
+
+	for bw in $tc_bw; do
+		local tc=${bw%%:*}
+		local expected_value=${bw##*:}
+		local api_value
+		api_value=$(rate_attr_get "$handle" tc_"$tc")
+		if [ "$api_value" = "null" ]; then
+			api_value=0
+		fi
+		[ "$api_value" == "$expected_value" ]
+		check_err $? "Unexpected tc-bw value for tc$tc: $api_value != $expected_value"
+	done
+}
+
 rate_node_add()
 {
 	local handle=$1
@@ -649,6 +689,13 @@ rate_test()
 		rate=$(($rate+100))
 	done
 
+	local tc_bw="0:0 1:40 2:0 3:0 4:0 5:0 6:60 7:0"
+	for r_obj in $leafs
+	do
+		rate_attr_tc_bw_check "$r_obj" "$tc_bw" \
+			"$DEBUGFS_DIR"/ports/"${r_obj##*/}"
+	done
+
 	local node1_name='group1'
 	local node1="$DL_HANDLE/$node1_name"
 	rate_node_add "$node1"
@@ -666,6 +713,12 @@ rate_test()
 	rate_attr_tx_rate_check $node1 tx_max $node_tx_max \
 		$DEBUGFS_DIR/rate_nodes/${node1##*/}/tx_max
 
+
+	local tc_bw="0:20 1:0 2:0 3:0 4:0 5:20 6:60 7:0"
+	rate_attr_tc_bw_check $node1 "$tc_bw" \
+		"$DEBUGFS_DIR"/rate_nodes/"${node1##*/}"
+
+
 	rate_node_del "$node1"
 	check_err $? "Failed to delete node $node1"
 	local num_nodes=`rate_nodes_get $DL_HANDLE | wc -w`