phylink: switch to relying on rtnetlink lock

Switch to relying on the rtnetlink lock rather than our private config
mutex to ensure proper locking.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 52 insertions, 92 deletions

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index bc1f2e63d541..f180b947d090 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -18,6 +18,7 @@
 #include <linux/phy.h>
 #include <linux/phy_fixed.h>
 #include <linux/phylink.h>
+#include <linux/rtnetlink.h>
 #include <linux/spinlock.h>
 #include <linux/workqueue.h>
 
@@ -42,7 +43,6 @@ struct phylink {
 	struct list_head node;
 	struct net_device *netdev;
 	const struct phylink_mac_ops *ops;
-	struct mutex config_mutex;
 
 	unsigned long phylink_disable_state; /* bitmask of disables */
 	struct phy_device *phydev;
@@ -56,7 +56,7 @@ struct phylink {
 	struct phylink_link_state link_config;
 	struct gpio_desc *link_gpio;
 
-	struct mutex state_mutex;	/* may be taken within config_mutex */
+	struct mutex state_mutex;
 	struct phylink_link_state phy_state;
 	struct work_struct resolve;
 
@@ -463,7 +463,6 @@ struct phylink *phylink_create(struct net_device *ndev, struct device_node *np,
 		return ERR_PTR(-ENOMEM);
 
 	mutex_init(&pl->state_mutex);
-	mutex_init(&pl->config_mutex);
 	INIT_WORK(&pl->resolve, phylink_resolve);
 	pl->netdev = ndev;
 	pl->phy_state.interface = iface;
@@ -548,7 +547,6 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
 	if (ret)
 		return ret;
 
-	mutex_lock(&pl->config_mutex);
 	phy->phylink = pl;
 	phy->phy_link_change = phylink_phy_change;
 
@@ -576,8 +574,6 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
 	if (phy->irq > 0)
 		phy_start_interrupts(phy);
 
-	mutex_unlock(&pl->config_mutex);
-
 	return 0;
 }
 
@@ -640,7 +636,8 @@ void phylink_disconnect_phy(struct phylink *pl)
 {
 	struct phy_device *phy;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	phy = pl->phydev;
 
 	mutex_lock(&pl->state_mutex);
@@ -650,8 +647,6 @@ void phylink_disconnect_phy(struct phylink *pl)
 
 	if (phy)
 		phy_disconnect(phy);
-
-	mutex_unlock(&pl->config_mutex);
 }
 EXPORT_SYMBOL_GPL(phylink_disconnect_phy);
 
@@ -666,7 +661,7 @@ EXPORT_SYMBOL_GPL(phylink_mac_change);
 
 void phylink_start(struct phylink *pl)
 {
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
 
 	netdev_info(pl->netdev, "configuring for %s link mode\n",
 		    phylink_an_mode_str(pl->link_an_mode));
@@ -683,34 +678,30 @@ void phylink_start(struct phylink *pl)
 
 	if (pl->phydev)
 		phy_start(pl->phydev);
-
-	mutex_unlock(&pl->config_mutex);
 }
 EXPORT_SYMBOL_GPL(phylink_start);
 
 void phylink_stop(struct phylink *pl)
 {
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
 
 	if (pl->phydev)
 		phy_stop(pl->phydev);
 
 	set_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
 	flush_work(&pl->resolve);
-
-	mutex_unlock(&pl->config_mutex);
 }
 EXPORT_SYMBOL_GPL(phylink_stop);
 
 void phylink_ethtool_get_wol(struct phylink *pl, struct ethtool_wolinfo *wol)
 {
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	wol->supported = 0;
 	wol->wolopts = 0;
 
-	mutex_lock(&pl->config_mutex);
 	if (pl->phydev)
 		phy_ethtool_get_wol(pl->phydev, wol);
-	mutex_unlock(&pl->config_mutex);
 }
 EXPORT_SYMBOL_GPL(phylink_ethtool_get_wol);
 
@@ -718,10 +709,10 @@ int phylink_ethtool_set_wol(struct phylink *pl, struct ethtool_wolinfo *wol)
 {
 	int ret = -EOPNOTSUPP;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->phydev)
 		ret = phy_ethtool_set_wol(pl->phydev, wol);
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -749,12 +740,14 @@ static void phylink_get_ksettings(const struct phylink_link_state *state,
 				AUTONEG_DISABLE;
 }
 
-static int __phylink_ethtool_ksettings_get(struct phylink *pl,
-					   struct ethtool_link_ksettings *kset)
+int phylink_ethtool_ksettings_get(struct phylink *pl,
+	struct ethtool_link_ksettings *kset)
 {
 	struct phylink_link_state link_state;
 	int ret;
 
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->phydev) {
 		ret = phy_ethtool_ksettings_get(pl->phydev, kset);
 		if (ret)
@@ -795,26 +788,20 @@ static int __phylink_ethtool_ksettings_get(struct phylink *pl,
 
 	return 0;
 }
-
-int phylink_ethtool_ksettings_get(struct phylink *pl,
-	struct ethtool_link_ksettings *kset)
-{
-	int ret;
-
-	mutex_lock(&pl->config_mutex);
-	ret = __phylink_ethtool_ksettings_get(pl, kset);
-	mutex_unlock(&pl->config_mutex);
-
-	return ret;
-}
 EXPORT_SYMBOL_GPL(phylink_ethtool_ksettings_get);
 
-static int __phylink_ethtool_ksettings_set(struct phylink *pl,
-					   const struct ethtool_link_ksettings *kset)
+int phylink_ethtool_ksettings_set(struct phylink *pl,
+	const struct ethtool_link_ksettings *kset)
 {
 	struct ethtool_link_ksettings our_kset = *kset;
 	int ret;
 
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (kset->base.autoneg != AUTONEG_DISABLE &&
+	    kset->base.autoneg != AUTONEG_ENABLE)
+		return -EINVAL;
+
 	/* Mask out unsupported advertisments */
 	linkmode_and(our_kset.link_modes.advertising,
 		     kset->link_modes.advertising, pl->supported);
@@ -886,33 +873,17 @@ static int __phylink_ethtool_ksettings_set(struct phylink *pl,
 
 	return ret;
 }
-
-int phylink_ethtool_ksettings_set(struct phylink *pl,
-	const struct ethtool_link_ksettings *kset)
-{
-	int ret;
-
-	if (kset->base.autoneg != AUTONEG_DISABLE &&
-	    kset->base.autoneg != AUTONEG_ENABLE)
-		return -EINVAL;
-
-	mutex_lock(&pl->config_mutex);
-	ret = __phylink_ethtool_ksettings_set(pl, kset);
-	mutex_unlock(&pl->config_mutex);
-
-	return ret;
-}
 EXPORT_SYMBOL_GPL(phylink_ethtool_ksettings_set);
 
 int phylink_ethtool_nway_reset(struct phylink *pl)
 {
 	int ret = 0;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->phydev)
 		ret = phy_restart_aneg(pl->phydev);
 	phylink_mac_an_restart(pl);
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -921,21 +892,21 @@ EXPORT_SYMBOL_GPL(phylink_ethtool_nway_reset);
 void phylink_ethtool_get_pauseparam(struct phylink *pl,
 				    struct ethtool_pauseparam *pause)
 {
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
 
 	pause->autoneg = !!(pl->link_config.pause & MLO_PAUSE_AN);
 	pause->rx_pause = !!(pl->link_config.pause & MLO_PAUSE_RX);
 	pause->tx_pause = !!(pl->link_config.pause & MLO_PAUSE_TX);
-
-	mutex_unlock(&pl->config_mutex);
 }
 EXPORT_SYMBOL_GPL(phylink_ethtool_get_pauseparam);
 
-static int __phylink_ethtool_set_pauseparam(struct phylink *pl,
-					    struct ethtool_pauseparam *pause)
+int phylink_ethtool_set_pauseparam(struct phylink *pl,
+				   struct ethtool_pauseparam *pause)
 {
 	struct phylink_link_state *config = &pl->link_config;
 
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (!phylink_test(pl->supported, Pause) &&
 	    !phylink_test(pl->supported, Asym_Pause))
 		return -EOPNOTSUPP;
@@ -977,18 +948,6 @@ static int __phylink_ethtool_set_pauseparam(struct phylink *pl,
 
 	return 0;
 }
-
-int phylink_ethtool_set_pauseparam(struct phylink *pl,
-				   struct ethtool_pauseparam *pause)
-{
-	int ret;
-
-	mutex_lock(&pl->config_mutex);
-	ret = __phylink_ethtool_set_pauseparam(pl, pause);
-	mutex_unlock(&pl->config_mutex);
-
-	return ret;
-}
 EXPORT_SYMBOL_GPL(phylink_ethtool_set_pauseparam);
 
 int phylink_ethtool_get_module_info(struct phylink *pl,
@@ -996,12 +955,11 @@ int phylink_ethtool_get_module_info(struct phylink *pl,
 {
 	int ret = -EOPNOTSUPP;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->module_ops)
 		ret = pl->module_ops->get_module_info(pl->module_data,
 						      modinfo);
-	mutex_unlock(&pl->config_mutex);
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(phylink_ethtool_get_module_info);
@@ -1011,11 +969,11 @@ int phylink_ethtool_get_module_eeprom(struct phylink *pl,
 {
 	int ret = -EOPNOTSUPP;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->module_ops)
 		ret = pl->module_ops->get_module_eeprom(pl->module_data, ee,
 							buf);
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -1025,10 +983,10 @@ int phylink_init_eee(struct phylink *pl, bool clk_stop_enable)
 {
 	int ret = -EPROTONOSUPPORT;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->phydev)
 		ret = phy_init_eee(pl->phydev, clk_stop_enable);
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -1038,10 +996,10 @@ int phylink_get_eee_err(struct phylink *pl)
 {
 	int ret = 0;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->phydev)
 		ret = phy_get_eee_err(pl->phydev);
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -1051,10 +1009,10 @@ int phylink_ethtool_get_eee(struct phylink *pl, struct ethtool_eee *eee)
 {
 	int ret = -EOPNOTSUPP;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->phydev)
 		ret = phy_ethtool_get_eee(pl->phydev, eee);
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -1064,10 +1022,10 @@ int phylink_ethtool_set_eee(struct phylink *pl, struct ethtool_eee *eee)
 {
 	int ret = -EOPNOTSUPP;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->phydev)
 		ret = phy_ethtool_set_eee(pl->phydev, eee);
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -1240,7 +1198,7 @@ int phylink_mii_ioctl(struct phylink *pl, struct ifreq *ifr, int cmd)
 	struct mii_ioctl_data *mii = if_mii(ifr);
 	int  ret;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
 
 	if (pl->phydev) {
 		/* PHYs only exist for MLO_AN_PHY and MLO_AN_SGMII */
@@ -1289,8 +1247,6 @@ int phylink_mii_ioctl(struct phylink *pl, struct ifreq *ifr, int cmd)
 		}
 	}
 
-	mutex_unlock(&pl->config_mutex);
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(phylink_mii_ioctl);
@@ -1302,13 +1258,13 @@ int phylink_register_module(struct phylink *pl, void *data,
 {
 	int ret = -EBUSY;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (!pl->module_ops) {
 		pl->module_ops = ops;
 		pl->module_data = data;
 		ret = 0;
 	}
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -1318,13 +1274,13 @@ int phylink_unregister_module(struct phylink *pl, void *data)
 {
 	int ret = -EINVAL;
 
-	mutex_lock(&pl->config_mutex);
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	if (pl->module_data == data) {
 		pl->module_ops = NULL;
 		pl->module_data = NULL;
 		ret = 0;
 	}
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }
@@ -1332,6 +1288,8 @@ EXPORT_SYMBOL_GPL(phylink_unregister_module);
 
 void phylink_disable(struct phylink *pl)
 {
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	set_bit(PHYLINK_DISABLE_LINK, &pl->phylink_disable_state);
 	flush_work(&pl->resolve);
 
@@ -1341,6 +1299,8 @@ EXPORT_SYMBOL_GPL(phylink_disable);
 
 void phylink_enable(struct phylink *pl)
 {
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	clear_bit(PHYLINK_DISABLE_LINK, &pl->phylink_disable_state);
 	phylink_run_resolve(pl);
 }
@@ -1352,6 +1312,8 @@ int phylink_set_link(struct phylink *pl, unsigned int mode, u8 port,
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask);
 	int ret = 0;
 
+	WARN_ON(!lockdep_rtnl_is_held());
+
 	netdev_dbg(pl->netdev, "requesting link mode %s with support %*pb\n",
 		   phylink_an_mode_str(mode),
 		   __ETHTOOL_LINK_MODE_MASK_NBITS, support);
@@ -1366,7 +1328,6 @@ int phylink_set_link(struct phylink *pl, unsigned int mode, u8 port,
 	if (ret && mode != MLO_AN_PHY)
 		return ret;
 
-	mutex_lock(&pl->config_mutex);
 	if (mode == MLO_AN_8023Z && pl->phydev) {
 		ret = -EINVAL;
 	} else {
@@ -1394,7 +1355,6 @@ int phylink_set_link(struct phylink *pl, unsigned int mode, u8 port,
 					 &pl->phylink_disable_state))
 			phylink_mac_config(pl, &pl->link_config);
 	}
-	mutex_unlock(&pl->config_mutex);
 
 	return ret;
 }