openwrt/target/linux/generic/backport-6.6/764-v6.10-net-dsa-allow-DSA-switch-drivers-to-provide-their-ow.patch

From c22d8240fcd73a1c3ec8dcb055bd583fb970c375 Mon Sep 17 00:00:00 2001
From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Date: Wed, 10 Apr 2024 20:42:43 +0100
Subject: [PATCH 2/2] net: dsa: allow DSA switch drivers to provide their own
 phylink mac ops

Rather than having a shim for each and every phylink MAC operation,
allow DSA switch drivers to provide their own ops structure. When a
DSA driver provides the phylink MAC operations, the shimmed ops must
not be provided, so fail an attempt to register a switch with both
the phylink_mac_ops in struct dsa_switch and the phylink_mac_*
operations populated in dsa_switch_ops populated.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/E1rudqF-006K9H-Cc@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/net/dsa.h |  5 +++++
 net/dsa/dsa.c     | 11 +++++++++++
 net/dsa/port.c    | 26 ++++++++++++++++++++------
 3 files changed, 36 insertions(+), 6 deletions(-)

--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -458,6 +458,11 @@ struct dsa_switch {
 	const struct dsa_switch_ops	*ops;
 
 	/*
+	 * Allow a DSA switch driver to override the phylink MAC ops
+	 */
+	const struct phylink_mac_ops	*phylink_mac_ops;
+
+	/*
 	 * Slave mii_bus and devices for the individual ports.
 	 */
 	u32			phys_mii_mask;
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -1510,6 +1510,17 @@ static int dsa_switch_probe(struct dsa_s
 	if (!ds->num_ports)
 		return -EINVAL;
 
+	if (ds->phylink_mac_ops) {
+		if (ds->ops->phylink_mac_select_pcs ||
+		    ds->ops->phylink_mac_prepare ||
+		    ds->ops->phylink_mac_config ||
+		    ds->ops->phylink_mac_finish ||
+		    ds->ops->phylink_mac_link_down ||
+		    ds->ops->phylink_mac_link_up ||
+		    ds->ops->adjust_link)
+			return -EINVAL;
+	}
+
 	if (np) {
 		err = dsa_switch_parse_of(ds, np);
 		if (err)
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -1677,6 +1677,7 @@ static const struct phylink_mac_ops dsa_
 
 int dsa_port_phylink_create(struct dsa_port *dp)
 {
+	const struct phylink_mac_ops *mac_ops;
 	struct dsa_switch *ds = dp->ds;
 	phy_interface_t mode;
 	struct phylink *pl;
@@ -1700,8 +1701,12 @@ int dsa_port_phylink_create(struct dsa_p
 		}
 	}
 
-	pl = phylink_create(&dp->pl_config, of_fwnode_handle(dp->dn),
-			    mode, &dsa_port_phylink_mac_ops);
+	mac_ops = &dsa_port_phylink_mac_ops;
+	if (ds->phylink_mac_ops)
+		mac_ops = ds->phylink_mac_ops;
+
+	pl = phylink_create(&dp->pl_config, of_fwnode_handle(dp->dn), mode,
+			    mac_ops);
 	if (IS_ERR(pl)) {
 		pr_err("error creating PHYLINK: %ld\n", PTR_ERR(pl));
 		return PTR_ERR(pl);
@@ -1967,12 +1972,23 @@ static void dsa_shared_port_validate_of(
 		dn, dsa_port_is_cpu(dp) ? "CPU" : "DSA", dp->index);
 }
 
+static void dsa_shared_port_link_down(struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->phylink_mac_ops && ds->phylink_mac_ops->mac_link_down)
+		ds->phylink_mac_ops->mac_link_down(&dp->pl_config, MLO_AN_FIXED,
+						   PHY_INTERFACE_MODE_NA);
+	else if (ds->ops->phylink_mac_link_down)
+		ds->ops->phylink_mac_link_down(ds, dp->index, MLO_AN_FIXED,
+					       PHY_INTERFACE_MODE_NA);
+}
+
 int dsa_shared_port_link_register_of(struct dsa_port *dp)
 {
 	struct dsa_switch *ds = dp->ds;
 	bool missing_link_description;
 	bool missing_phy_mode;
-	int port = dp->index;
 
 	dsa_shared_port_validate_of(dp, &missing_phy_mode,
 				    &missing_link_description);
@@ -1988,9 +2004,7 @@ int dsa_shared_port_link_register_of(str
 				 "Skipping phylink registration for %s port %d\n",
 				 dsa_port_is_cpu(dp) ? "CPU" : "DSA", dp->index);
 		} else {
-			if (ds->ops->phylink_mac_link_down)
-				ds->ops->phylink_mac_link_down(ds, port,
-					MLO_AN_FIXED, PHY_INTERFACE_MODE_NA);
+			dsa_shared_port_link_down(dp);
 
 			return dsa_shared_port_phylink_register(dp);
 		}