From: Ido Schimmel <idosch@mellanox.com>
Date: Thu, 30 Apr 2020 20:01:15 +0300
Subject: mlxsw: spectrum_span: Use new analyzed ports list during speed / MTU
 change
Patch-mainline: v5.8-rc1
Git-commit: 835d6b8c1a35eafba3faaf4b809f6d84517467f1
References: bsc#1176774

As previously explained, each port whose outgoing traffic is analyzed
needs to have an egress mirror buffer.

The size of the egress mirror buffer is calculated based on various
parameters, two of which are the speed and the MTU of the port.

Therefore, when the MTU or the speed of a port change, the SPAN code is
called to see if the egress mirror buffer of the port needs to be
adjusted.

Currently, this is done by traversing all the SPAN agents and for each
SPAN agent the list of bound ports is traversed.

Instead of the above, traverse the recently added list of analyzed
ports.

This will later allow us to remove the old SPAN API.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c |   72 +++++++++-----------
 1 file changed, 35 insertions(+), 37 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
@@ -776,24 +776,6 @@ static int mlxsw_sp_span_entry_put(struc
 	return 0;
 }
 
-static bool mlxsw_sp_span_is_egress_mirror(struct mlxsw_sp_port *port)
-{
-	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
-	struct mlxsw_sp_span_inspected_port *p;
-	int i;
-
-	for (i = 0; i < mlxsw_sp->span->entries_count; i++) {
-		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span->entries[i];
-
-		list_for_each_entry(p, &curr->bound_ports_list, list)
-			if (p->local_port == port->local_port &&
-			    p->type == MLXSW_SP_SPAN_EGRESS)
-				return true;
-	}
-
-	return false;
-}
-
 static int
 mlxsw_sp_span_port_buffer_update(struct mlxsw_sp_port *mlxsw_sp_port, u16 mtu)
 {
@@ -823,20 +805,45 @@ static void mlxsw_sp_span_port_buffer_di
 	mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
 }
 
+static struct mlxsw_sp_span_analyzed_port *
+mlxsw_sp_span_analyzed_port_find(struct mlxsw_sp_span *span, u8 local_port,
+				 bool ingress)
+{
+	struct mlxsw_sp_span_analyzed_port *analyzed_port;
+
+	list_for_each_entry(analyzed_port, &span->analyzed_ports_list, list) {
+		if (analyzed_port->local_port == local_port &&
+		    analyzed_port->ingress == ingress)
+			return analyzed_port;
+	}
+
+	return NULL;
+}
+
 int mlxsw_sp_span_port_mtu_update(struct mlxsw_sp_port *port, u16 mtu)
 {
+	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
+	int err = 0;
+
 	/* If port is egress mirrored, the shared buffer size should be
 	 * updated according to the mtu value
 	 */
-	if (mlxsw_sp_span_is_egress_mirror(port))
-		return mlxsw_sp_span_port_buffer_update(port, mtu);
-	return 0;
+	mutex_lock(&mlxsw_sp->span->analyzed_ports_lock);
+
+	if (mlxsw_sp_span_analyzed_port_find(mlxsw_sp->span, port->local_port,
+					     false))
+		err = mlxsw_sp_span_port_buffer_update(port, mtu);
+
+	mutex_unlock(&mlxsw_sp->span->analyzed_ports_lock);
+
+	return err;
 }
 
 void mlxsw_sp_span_speed_update_work(struct work_struct *work)
 {
 	struct delayed_work *dwork = to_delayed_work(work);
 	struct mlxsw_sp_port *mlxsw_sp_port;
+	struct mlxsw_sp *mlxsw_sp;
 
 	mlxsw_sp_port = container_of(dwork, struct mlxsw_sp_port,
 				     span.speed_update_dw);
@@ -844,9 +851,15 @@ void mlxsw_sp_span_speed_update_work(str
 	/* If port is egress mirrored, the shared buffer size should be
 	 * updated according to the speed value.
 	 */
-	if (mlxsw_sp_span_is_egress_mirror(mlxsw_sp_port))
+	mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	mutex_lock(&mlxsw_sp->span->analyzed_ports_lock);
+
+	if (mlxsw_sp_span_analyzed_port_find(mlxsw_sp->span,
+					     mlxsw_sp_port->local_port, false))
 		mlxsw_sp_span_port_buffer_update(mlxsw_sp_port,
 						 mlxsw_sp_port->dev->mtu);
+
+	mutex_unlock(&mlxsw_sp->span->analyzed_ports_lock);
 }
 
 static struct mlxsw_sp_span_inspected_port *
@@ -1118,21 +1131,6 @@ void mlxsw_sp_span_agent_put(struct mlxs
 }
 
 static struct mlxsw_sp_span_analyzed_port *
-mlxsw_sp_span_analyzed_port_find(struct mlxsw_sp_span *span, u8 local_port,
-				 bool ingress)
-{
-	struct mlxsw_sp_span_analyzed_port *analyzed_port;
-
-	list_for_each_entry(analyzed_port, &span->analyzed_ports_list, list) {
-		if (analyzed_port->local_port == local_port &&
-		    analyzed_port->ingress == ingress)
-			return analyzed_port;
-	}
-
-	return NULL;
-}
-
-static struct mlxsw_sp_span_analyzed_port *
 mlxsw_sp_span_analyzed_port_create(struct mlxsw_sp_span *span,
 				   struct mlxsw_sp_port *mlxsw_sp_port,
 				   bool ingress)