Merge branch 'net-dsa-microchip-provide-wake-on-lan-support-part-2'

Oleksij Rempel says:

====================
net: dsa: microchip: provide Wake on LAN support (part 2)

This patch series introduces extensive Wake on LAN (WoL) support for the
Microchip KSZ9477 family of switches, coupled with some code refactoring
and error handling enhancements. The principal aim is to enable and
manage Wake on Magic Packet and other PHY event triggers for waking up
the system, whilst ensuring that the switch isn't reset during a
shutdown if WoL is active.

The Wake on LAN functionality is optional and is particularly beneficial
if the PME pins are connected to the SoC as a wake source or to a PMIC
that can enable or wake the SoC.
====================

Link: https://lore.kernel.org/r/20231026051051.2316937-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 92 insertions, 12 deletions

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index de788f424a3f..3fed406fb46a 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -321,6 +321,7 @@ static const struct ksz_dev_ops ksz9477_dev_ops = {
 	.phylink_mac_link_up = ksz9477_phylink_mac_link_up,
 	.get_wol = ksz9477_get_wol,
 	.set_wol = ksz9477_set_wol,
+	.wol_pre_shutdown = ksz9477_wol_pre_shutdown,
 	.config_cpu_port = ksz9477_config_cpu_port,
 	.tc_cbs_set_cinc = ksz9477_tc_cbs_set_cinc,
 	.enable_stp_addr = ksz9477_enable_stp_addr,
@@ -3569,6 +3570,7 @@ static int ksz_port_set_mac_address(struct dsa_switch *ds, int port,
 				    const unsigned char *addr)
 {
 	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct ethtool_wolinfo wol;
 
 	if (dp->hsr_dev) {
 		dev_err(ds->dev,
@@ -3577,25 +3579,69 @@ static int ksz_port_set_mac_address(struct dsa_switch *ds, int port,
 		return -EBUSY;
 	}
 
+	ksz_get_wol(ds, dp->index, &wol);
+	if (wol.wolopts & WAKE_MAGIC) {
+		dev_err(ds->dev,
+			"Cannot change MAC address on port %d with active Wake on Magic Packet\n",
+			port);
+		return -EBUSY;
+	}
+
 	return 0;
 }
 
-/* Program the switch's MAC address register with the MAC address of the
- * requesting user port. This single address is used by the switch for multiple
- * features, like HSR self-address filtering and WoL. Other user ports are
- * allowed to share ownership of this address as long as their MAC address is
- * the same. The user ports' MAC addresses must not change while they have
- * ownership of the switch MAC address.
+/**
+ * ksz_is_port_mac_global_usable - Check if the MAC address on a given port
+ *                                 can be used as a global address.
+ * @ds: Pointer to the DSA switch structure.
+ * @port: The port number on which the MAC address is to be checked.
+ *
+ * This function examines the MAC address set on the specified port and
+ * determines if it can be used as a global address for the switch.
+ *
+ * Return: true if the port's MAC address can be used as a global address, false
+ * otherwise.
  */
-static int ksz_switch_macaddr_get(struct dsa_switch *ds, int port,
-				  struct netlink_ext_ack *extack)
+bool ksz_is_port_mac_global_usable(struct dsa_switch *ds, int port)
+{
+	struct net_device *user = dsa_to_port(ds, port)->user;
+	const unsigned char *addr = user->dev_addr;
+	struct ksz_switch_macaddr *switch_macaddr;
+	struct ksz_device *dev = ds->priv;
+
+	ASSERT_RTNL();
+
+	switch_macaddr = dev->switch_macaddr;
+	if (switch_macaddr && !ether_addr_equal(switch_macaddr->addr, addr))
+		return false;
+
+	return true;
+}
+
+/**
+ * ksz_switch_macaddr_get - Program the switch's MAC address register.
+ * @ds: DSA switch instance.
+ * @port: Port number.
+ * @extack: Netlink extended acknowledgment.
+ *
+ * This function programs the switch's MAC address register with the MAC address
+ * of the requesting user port. This single address is used by the switch for
+ * multiple features like HSR self-address filtering and WoL. Other user ports
+ * can share ownership of this address as long as their MAC address is the same.
+ * The MAC addresses of user ports must not change while they have ownership of
+ * the switch MAC address.
+ *
+ * Return: 0 on success, or other error codes on failure.
+ */
+int ksz_switch_macaddr_get(struct dsa_switch *ds, int port,
+			   struct netlink_ext_ack *extack)
 {
 	struct net_device *user = dsa_to_port(ds, port)->user;
 	const unsigned char *addr = user->dev_addr;
 	struct ksz_switch_macaddr *switch_macaddr;
 	struct ksz_device *dev = ds->priv;
 	const u16 *regs = dev->info->regs;
-	int i;
+	int i, ret;
 
 	/* Make sure concurrent MAC address changes are blocked */
 	ASSERT_RTNL();
@@ -3622,13 +3668,23 @@ static int ksz_switch_macaddr_get(struct dsa_switch *ds, int port,
 	dev->switch_macaddr = switch_macaddr;
 
 	/* Program the switch MAC address to hardware */
-	for (i = 0; i < ETH_ALEN; i++)
-		ksz_write8(dev, regs[REG_SW_MAC_ADDR] + i, addr[i]);
+	for (i = 0; i < ETH_ALEN; i++) {
+		ret = ksz_write8(dev, regs[REG_SW_MAC_ADDR] + i, addr[i]);
+		if (ret)
+			goto macaddr_drop;
+	}
 
 	return 0;
+
+macaddr_drop:
+	dev->switch_macaddr = NULL;
+	refcount_set(&switch_macaddr->refcount, 0);
+	kfree(switch_macaddr);
+
+	return ret;
 }
 
-static void ksz_switch_macaddr_put(struct dsa_switch *ds)
+void ksz_switch_macaddr_put(struct dsa_switch *ds)
 {
 	struct ksz_switch_macaddr *switch_macaddr;
 	struct ksz_device *dev = ds->priv;
@@ -3790,6 +3846,30 @@ struct ksz_device *ksz_switch_alloc(struct device *base, void *priv)
 }
 EXPORT_SYMBOL(ksz_switch_alloc);
 
+/**
+ * ksz_switch_shutdown - Shutdown routine for the switch device.
+ * @dev: The switch device structure.
+ *
+ * This function is responsible for initiating a shutdown sequence for the
+ * switch device. It invokes the reset operation defined in the device
+ * operations, if available, to reset the switch. Subsequently, it calls the
+ * DSA framework's shutdown function to ensure a proper shutdown of the DSA
+ * switch.
+ */
+void ksz_switch_shutdown(struct ksz_device *dev)
+{
+	bool wol_enabled = false;
+
+	if (dev->dev_ops->wol_pre_shutdown)
+		dev->dev_ops->wol_pre_shutdown(dev, &wol_enabled);
+
+	if (dev->dev_ops->reset && !wol_enabled)
+		dev->dev_ops->reset(dev);
+
+	dsa_switch_shutdown(dev->ds);
+}
+EXPORT_SYMBOL(ksz_switch_shutdown);
+
 static void ksz_parse_rgmii_delay(struct ksz_device *dev, int port_num,
 				  struct device_node *port_dn)
 {