diff mbox series

[net-next,7/9] mlxsw: spectrum_qdisc: Validate qdisc topology

Message ID 20211019080712.705464-8-idosch@idosch.org (mailing list archive)
State Accepted
Commit c2792f38caae108cd1a082b9fa838d47f051ad50
Delegated to: Netdev Maintainers
Headers show
Series mlxsw: Multi-level qdisc offload | expand

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Context Check Description
netdev/cover_letter success Series has a cover letter
netdev/fixes_present success Fixes tag not required for -next series
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success No Fixes tag
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success No static functions without inline keyword in header files

Commit Message

Ido Schimmel Oct. 19, 2021, 8:07 a.m. UTC 
From: Petr Machata <petrm@nvidia.com>

A following patch will enable offloading qdiscs that are deeper than
directly under root qdisc. Currently the topology validation consists of
demanding a root qdisc position for ETS and PRIO. Since RED and TBF are
considered classless, this is enough. In order to prevent some nonsensical
combinations when RED and TBF become classful, introduce a more general
topology validator.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 .../ethernet/mellanox/mlxsw/spectrum_qdisc.c  | 91 +++++++++++++++++--
 1 file changed, 82 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
index 412394e02d2a..b865fd3ccf31 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
@@ -157,8 +157,7 @@  mlxsw_sp_qdisc_walk_cb_find(struct mlxsw_sp_qdisc *qdisc, void *data)
 }
 
 static struct mlxsw_sp_qdisc *
-mlxsw_sp_qdisc_find(struct mlxsw_sp_port *mlxsw_sp_port, u32 parent,
-		    bool root_only)
+mlxsw_sp_qdisc_find(struct mlxsw_sp_port *mlxsw_sp_port, u32 parent)
 {
 	struct mlxsw_sp_qdisc_state *qdisc_state = mlxsw_sp_port->qdisc;
 
@@ -166,8 +165,6 @@  mlxsw_sp_qdisc_find(struct mlxsw_sp_port *mlxsw_sp_port, u32 parent,
 		return NULL;
 	if (parent == TC_H_ROOT)
 		return &qdisc_state->root_qdisc;
-	if (root_only)
-		return NULL;
 	return mlxsw_sp_qdisc_walk(&qdisc_state->root_qdisc,
 				   mlxsw_sp_qdisc_walk_cb_find, &parent);
 }
@@ -268,6 +265,78 @@  mlxsw_sp_qdisc_destroy(struct mlxsw_sp_port *mlxsw_sp_port,
 	return err_hdroom ?: err;
 }
 
+struct mlxsw_sp_qdisc_tree_validate {
+	bool forbid_ets;
+	bool forbid_tbf;
+	bool forbid_red;
+};
+
+static int
+__mlxsw_sp_qdisc_tree_validate(struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
+			       struct mlxsw_sp_qdisc_tree_validate validate);
+
+static int
+mlxsw_sp_qdisc_tree_validate_children(struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
+				      struct mlxsw_sp_qdisc_tree_validate validate)
+{
+	unsigned int i;
+	int err;
+
+	for (i = 0; i < mlxsw_sp_qdisc->num_classes; i++) {
+		err = __mlxsw_sp_qdisc_tree_validate(&mlxsw_sp_qdisc->qdiscs[i],
+						     validate);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int
+__mlxsw_sp_qdisc_tree_validate(struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
+			       struct mlxsw_sp_qdisc_tree_validate validate)
+{
+	if (!mlxsw_sp_qdisc->ops)
+		return 0;
+
+	switch (mlxsw_sp_qdisc->ops->type) {
+	case MLXSW_SP_QDISC_FIFO:
+		break;
+	case MLXSW_SP_QDISC_RED:
+		if (validate.forbid_red)
+			return -EINVAL;
+		validate.forbid_red = true;
+		validate.forbid_ets = true;
+		break;
+	case MLXSW_SP_QDISC_TBF:
+		if (validate.forbid_tbf)
+			return -EINVAL;
+		validate.forbid_tbf = true;
+		validate.forbid_ets = true;
+		break;
+	case MLXSW_SP_QDISC_PRIO:
+	case MLXSW_SP_QDISC_ETS:
+		if (validate.forbid_ets)
+			return -EINVAL;
+		validate.forbid_ets = true;
+		break;
+	default:
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	return mlxsw_sp_qdisc_tree_validate_children(mlxsw_sp_qdisc, validate);
+}
+
+static int mlxsw_sp_qdisc_tree_validate(struct mlxsw_sp_port *mlxsw_sp_port)
+{
+	struct mlxsw_sp_qdisc_tree_validate validate = {};
+	struct mlxsw_sp_qdisc *mlxsw_sp_qdisc;
+
+	mlxsw_sp_qdisc = &mlxsw_sp_port->qdisc->root_qdisc;
+	return __mlxsw_sp_qdisc_tree_validate(mlxsw_sp_qdisc, validate);
+}
+
 static int mlxsw_sp_qdisc_create(struct mlxsw_sp_port *mlxsw_sp_port,
 				 u32 handle,
 				 struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
@@ -310,6 +379,10 @@  static int mlxsw_sp_qdisc_create(struct mlxsw_sp_port *mlxsw_sp_port,
 	mlxsw_sp_qdisc->num_classes = ops->num_classes;
 	mlxsw_sp_qdisc->ops = ops;
 	mlxsw_sp_qdisc->handle = handle;
+	err = mlxsw_sp_qdisc_tree_validate(mlxsw_sp_port);
+	if (err)
+		goto err_replace;
+
 	err = ops->replace(mlxsw_sp_port, handle, mlxsw_sp_qdisc, params);
 	if (err)
 		goto err_replace;
@@ -748,7 +821,7 @@  static int __mlxsw_sp_setup_tc_red(struct mlxsw_sp_port *mlxsw_sp_port,
 {
 	struct mlxsw_sp_qdisc *mlxsw_sp_qdisc;
 
-	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent, false);
+	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent);
 	if (!mlxsw_sp_qdisc)
 		return -EOPNOTSUPP;
 
@@ -964,7 +1037,7 @@  static int __mlxsw_sp_setup_tc_tbf(struct mlxsw_sp_port *mlxsw_sp_port,
 {
 	struct mlxsw_sp_qdisc *mlxsw_sp_qdisc;
 
-	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent, false);
+	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent);
 	if (!mlxsw_sp_qdisc)
 		return -EOPNOTSUPP;
 
@@ -1070,7 +1143,7 @@  static int __mlxsw_sp_setup_tc_fifo(struct mlxsw_sp_port *mlxsw_sp_port,
 	unsigned int band;
 	u32 parent_handle;
 
-	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent, false);
+	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent);
 	if (!mlxsw_sp_qdisc && p->handle == TC_H_UNSPEC) {
 		parent_handle = TC_H_MAJ(p->parent);
 		if (parent_handle != qdisc_state->future_handle) {
@@ -1534,7 +1607,7 @@  static int __mlxsw_sp_setup_tc_prio(struct mlxsw_sp_port *mlxsw_sp_port,
 {
 	struct mlxsw_sp_qdisc *mlxsw_sp_qdisc;
 
-	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent, true);
+	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent);
 	if (!mlxsw_sp_qdisc)
 		return -EOPNOTSUPP;
 
@@ -1579,7 +1652,7 @@  static int __mlxsw_sp_setup_tc_ets(struct mlxsw_sp_port *mlxsw_sp_port,
 {
 	struct mlxsw_sp_qdisc *mlxsw_sp_qdisc;
 
-	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent, true);
+	mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent);
 	if (!mlxsw_sp_qdisc)
 		return -EOPNOTSUPP;