Commit 5a731857 authored by Carolina Jubran's avatar Carolina Jubran Committed by Jakub Kicinski
Browse files

net/mlx5: Simplify QoS normalization by removing error handling 



This change updates esw_qos_normalize_min_rate to not return errors,
significantly simplifying the code.

Normalization failures are software bugs, and it's unnecessary to
handle them with rollback mechanisms. Instead,
`esw_qos_update_sched_node_bw_share` and `esw_qos_normalize_min_rate`
now return void, with any errors logged as warnings to indicate
potential software issues.

This approach avoids compensating for hidden bugs and removes error
handling from all places that perform normalization, streamlining
future patches.

Signed-off-by: default avatarCarolina Jubran <cjubran@nvidia.com>
Reviewed-by: default avatarCosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: default avatarTariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20241107194357.683732-3-tariqt@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ab85ebf4

drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c

+17 −55
Original line number Diff line number Diff line
@@ -208,29 +208,23 @@ static u32 esw_qos_calc_bw_share(u32 min_rate, u32 divider, u32 fw_max) 
	return min_t(u32, max_t(u32, DIV_ROUND_UP(min_rate, divider), MLX5_MIN_BW_SHARE), fw_max);

}



static int esw_qos_update_sched_node_bw_share(struct mlx5_esw_sched_node *node,

static void esw_qos_update_sched_node_bw_share(struct mlx5_esw_sched_node *node,

					       u32 divider,

					       struct netlink_ext_ack *extack)

{

	u32 fw_max_bw_share = MLX5_CAP_QOS(node->esw->dev, max_tsar_bw_share);

	u32 bw_share;

	int err;



	bw_share = esw_qos_calc_bw_share(node->min_rate, divider, fw_max_bw_share);



	if (bw_share == node->bw_share)

		return 0;



	err = esw_qos_sched_elem_config(node, node->max_rate, bw_share, extack);

	if (err)

		return err;

		return;



	esw_qos_sched_elem_config(node, node->max_rate, bw_share, extack);

	node->bw_share = bw_share;



	return err;

}



static int esw_qos_normalize_min_rate(struct mlx5_eswitch *esw,

static void esw_qos_normalize_min_rate(struct mlx5_eswitch *esw,

				       struct mlx5_esw_sched_node *parent,

				       struct netlink_ext_ack *extack)

{
@@ -239,33 +233,24 @@ static int esw_qos_normalize_min_rate(struct mlx5_eswitch *esw, 
	struct mlx5_esw_sched_node *node;



	list_for_each_entry(node, nodes, entry) {

		int err;



		if (node->esw != esw || node->ix == esw->qos.root_tsar_ix)

			continue;



		err = esw_qos_update_sched_node_bw_share(node, divider, extack);

		if (err)

			return err;

		esw_qos_update_sched_node_bw_share(node, divider, extack);



		if (list_empty(&node->children))

			continue;



		err = esw_qos_normalize_min_rate(node->esw, node, extack);

		if (err)

			return err;

		esw_qos_normalize_min_rate(node->esw, node, extack);

	}



	return 0;

}



static int esw_qos_set_vport_min_rate(struct mlx5_vport *vport,

				      u32 min_rate, struct netlink_ext_ack *extack)

{

	struct mlx5_esw_sched_node *vport_node = vport->qos.sched_node;

	u32 fw_max_bw_share, previous_min_rate;

	bool min_rate_supported;

	int err;

	u32 fw_max_bw_share;



	esw_assert_qos_lock_held(vport_node->esw);

	fw_max_bw_share = MLX5_CAP_QOS(vport->dev, max_tsar_bw_share);
@@ -276,13 +261,10 @@ static int esw_qos_set_vport_min_rate(struct mlx5_vport *vport, 
	if (min_rate == vport_node->min_rate)

		return 0;



	previous_min_rate = vport_node->min_rate;

	vport_node->min_rate = min_rate;

	err = esw_qos_normalize_min_rate(vport_node->parent->esw, vport_node->parent, extack);

	if (err)

		vport_node->min_rate = previous_min_rate;

	esw_qos_normalize_min_rate(vport_node->parent->esw, vport_node->parent, extack);



	return err;

	return 0;

}



static int esw_qos_set_vport_max_rate(struct mlx5_vport *vport,
@@ -316,8 +298,6 @@ static int esw_qos_set_node_min_rate(struct mlx5_esw_sched_node *node, 
				     u32 min_rate, struct netlink_ext_ack *extack)

{

	struct mlx5_eswitch *esw = node->esw;

	u32 previous_min_rate;

	int err;



	if (!MLX5_CAP_QOS(esw->dev, esw_bw_share) ||

	    MLX5_CAP_QOS(esw->dev, max_tsar_bw_share) < MLX5_MIN_BW_SHARE)
@@ -326,19 +306,10 @@ static int esw_qos_set_node_min_rate(struct mlx5_esw_sched_node *node, 
	if (min_rate == node->min_rate)

		return 0;



	previous_min_rate = node->min_rate;

	node->min_rate = min_rate;

	err = esw_qos_normalize_min_rate(esw, NULL, extack);

	if (err) {

		NL_SET_ERR_MSG_MOD(extack, "E-Switch node min rate setting failed");



		/* Attempt restoring previous configuration */

		node->min_rate = previous_min_rate;

		if (esw_qos_normalize_min_rate(esw, NULL, extack))

			NL_SET_ERR_MSG_MOD(extack, "E-Switch BW share restore failed");

	}

	esw_qos_normalize_min_rate(esw, NULL, extack);



	return err;

	return 0;

}



static int esw_qos_set_node_max_rate(struct mlx5_esw_sched_node *node,
@@ -552,17 +523,11 @@ __esw_qos_create_vports_sched_node(struct mlx5_eswitch *esw, struct mlx5_esw_sch 
		goto err_alloc_node;

	}



	err = esw_qos_normalize_min_rate(esw, NULL, extack);

	if (err) {

		NL_SET_ERR_MSG_MOD(extack, "E-Switch nodes normalization failed");

		goto err_min_rate;

	}

	esw_qos_normalize_min_rate(esw, NULL, extack);

	trace_mlx5_esw_node_qos_create(esw->dev, node, node->ix);



	return node;



err_min_rate:

	__esw_qos_free_node(node);

err_alloc_node:

	if (mlx5_destroy_scheduling_element_cmd(esw->dev,

						SCHEDULING_HIERARCHY_E_SWITCH,
@@ -609,10 +574,7 @@ static int __esw_qos_destroy_node(struct mlx5_esw_sched_node *node, struct netli 
		NL_SET_ERR_MSG_MOD(extack, "E-Switch destroy TSAR_ID failed");

	__esw_qos_free_node(node);



	err = esw_qos_normalize_min_rate(esw, NULL, extack);

	if (err)

		NL_SET_ERR_MSG_MOD(extack, "E-Switch nodes normalization failed");



	esw_qos_normalize_min_rate(esw, NULL, extack);



	return err;

}