Merge branch 'Decoupling-PHYLINK-from-struct-net_device'

Ioana Ciornei says:

====================
Decoupling PHYLINK from struct net_device

Following two separate discussion threads in:
  https://www.spinics.net/lists/netdev/msg569087.html
and:
  https://www.spinics.net/lists/netdev/msg570450.html

Previous RFC patch set: https://www.spinics.net/lists/netdev/msg571995.html

PHYLINK was reworked in order to accept multiple operation types,
PHYLINK_NETDEV and PHYLINK_DEV, passed through a phylink_config
structure alongside the corresponding struct device.

One of the main concerns expressed in the RFC was that using notifiers
to signal the corresponding phylink_mac_ops would break PHYLINK's API
unity and that it would become harder to grep for its users.
Using the current approach, we maintain a common API for all users.
Also, printing useful information in PHYLINK, when decoupled from a
net_device, is achieved using dev_err&co on the struct device received
(in DSA's case is the device corresponding to the dsa_switch).

PHYLIB (which PHYLINK uses) was reworked to the extent that it does not
crash when connecting to a PHY and the net_device pointer is NULL.

Lastly, DSA has been reworked in its way that it handles PHYs for ports
that lack a net_device (CPU and DSA ports).  For these, it was
previously using PHYLIB and is now using the PHYLINK_DEV operation type.
Previously, a driver that wanted to support PHY operations on CPU/DSA
ports has to implement .adjust_link(). This patch set not only gives
drivers the options to use PHYLINK uniformly but also urges them to
convert to it. For compatibility, the old code is kept but it will be
removed once all drivers switch over.

The patchset was tested on the NXP LS1021A-TSN board having the
following Ethernet layout:
  https://lkml.org/lkml/2019/5/5/279
The CPU port was moved from the internal RGMII fixed-link (enet2 ->
switch port 4) to an external loopback Cat5 cable between the enet1 port
and the front-facing swp2 SJA1105 port. In this mode, both the master
and the CPU port have an attached PHY which detects link change events:

[   49.105426] fsl-gianfar soc:ethernet@2d50000 eth1: Link is Down
[   50.305486] sja1105 spi0.1: Link is Down
[   53.265596] fsl-gianfar soc:ethernet@2d50000 eth1: Link is Up - 1Gbps/Full - flow control off
[   54.466304] sja1105 spi0.1: Link is Up - 1Gbps/Full - flow control off

Changes in v2:
  - fixed sparse warnings
  - updated 'Documentation/ABI/testing/sysfs-class-net-phydev'
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 137 insertions, 83 deletions

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 74983593834b..68d0a89c52be 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -41,6 +41,9 @@ struct phylink {
 	/* private: */
 	struct net_device *netdev;
 	const struct phylink_mac_ops *ops;
+	struct phylink_config *config;
+	struct device *dev;
+	unsigned int old_link_state:1;
 
 	unsigned long phylink_disable_state; /* bitmask of disables */
 	struct phy_device *phydev;
@@ -65,6 +68,23 @@ struct phylink {
 	struct sfp_bus *sfp_bus;
 };
 
+#define phylink_printk(level, pl, fmt, ...) \
+	do { \
+		if ((pl)->config->type == PHYLINK_NETDEV) \
+			netdev_printk(level, (pl)->netdev, fmt, ##__VA_ARGS__); \
+		else if ((pl)->config->type == PHYLINK_DEV) \
+			dev_printk(level, (pl)->dev, fmt, ##__VA_ARGS__); \
+	} while (0)
+
+#define phylink_err(pl, fmt, ...) \
+	phylink_printk(KERN_ERR, pl, fmt, ##__VA_ARGS__)
+#define phylink_warn(pl, fmt, ...) \
+	phylink_printk(KERN_WARNING, pl, fmt, ##__VA_ARGS__)
+#define phylink_info(pl, fmt, ...) \
+	phylink_printk(KERN_INFO, pl, fmt, ##__VA_ARGS__)
+#define phylink_dbg(pl, fmt, ...) \
+	phylink_printk(KERN_DEBUG, pl, fmt, ##__VA_ARGS__)
+
 /**
  * phylink_set_port_modes() - set the port type modes in the ethtool mask
  * @mask: ethtool link mode mask
@@ -111,7 +131,7 @@ static const char *phylink_an_mode_str(unsigned int mode)
 static int phylink_validate(struct phylink *pl, unsigned long *supported,
 			    struct phylink_link_state *state)
 {
-	pl->ops->validate(pl->netdev, supported, state);
+	pl->ops->validate(pl->config, supported, state);
 
 	return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;
 }
@@ -161,7 +181,7 @@ static int phylink_parse_fixedlink(struct phylink *pl,
 		ret = fwnode_property_read_u32_array(fwnode, "fixed-link",
 						     NULL, 0);
 		if (ret != ARRAY_SIZE(prop)) {
-			netdev_err(pl->netdev, "broken fixed-link?\n");
+			phylink_err(pl, "broken fixed-link?\n");
 			return -EINVAL;
 		}
 
@@ -180,8 +200,8 @@ static int phylink_parse_fixedlink(struct phylink *pl,
 
 	if (pl->link_config.speed > SPEED_1000 &&
 	    pl->link_config.duplex != DUPLEX_FULL)
-		netdev_warn(pl->netdev, "fixed link specifies half duplex for %dMbps link?\n",
-			    pl->link_config.speed);
+		phylink_warn(pl, "fixed link specifies half duplex for %dMbps link?\n",
+			     pl->link_config.speed);
 
 	bitmap_fill(pl->supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
 	linkmode_copy(pl->link_config.advertising, pl->supported);
@@ -194,9 +214,9 @@ static int phylink_parse_fixedlink(struct phylink *pl,
 	if (s) {
 		__set_bit(s->bit, pl->supported);
 	} else {
-		netdev_warn(pl->netdev, "fixed link %s duplex %dMbps not recognised\n",
-			    pl->link_config.duplex == DUPLEX_FULL ? "full" : "half",
-			    pl->link_config.speed);
+		phylink_warn(pl, "fixed link %s duplex %dMbps not recognised\n",
+			     pl->link_config.duplex == DUPLEX_FULL ? "full" : "half",
+			     pl->link_config.speed);
 	}
 
 	linkmode_and(pl->link_config.advertising, pl->link_config.advertising,
@@ -221,8 +241,8 @@ static int phylink_parse_mode(struct phylink *pl, struct fwnode_handle *fwnode)
 	if (fwnode_property_read_string(fwnode, "managed", &managed) == 0 &&
 	    strcmp(managed, "in-band-status") == 0) {
 		if (pl->link_an_mode == MLO_AN_FIXED) {
-			netdev_err(pl->netdev,
-				   "can't use both fixed-link and in-band-status\n");
+			phylink_err(pl,
+				    "can't use both fixed-link and in-band-status\n");
 			return -EINVAL;
 		}
 
@@ -269,17 +289,17 @@ static int phylink_parse_mode(struct phylink *pl, struct fwnode_handle *fwnode)
 			break;
 
 		default:
-			netdev_err(pl->netdev,
-				   "incorrect link mode %s for in-band status\n",
-				   phy_modes(pl->link_config.interface));
+			phylink_err(pl,
+				    "incorrect link mode %s for in-band status\n",
+				    phy_modes(pl->link_config.interface));
 			return -EINVAL;
 		}
 
 		linkmode_copy(pl->link_config.advertising, pl->supported);
 
 		if (phylink_validate(pl, pl->supported, &pl->link_config)) {
-			netdev_err(pl->netdev,
-				   "failed to validate link configuration for in-band status\n");
+			phylink_err(pl,
+				    "failed to validate link configuration for in-band status\n");
 			return -EINVAL;
 		}
 	}
@@ -290,16 +310,16 @@ static int phylink_parse_mode(struct phylink *pl, struct fwnode_handle *fwnode)
 static void phylink_mac_config(struct phylink *pl,
 			       const struct phylink_link_state *state)
 {
-	netdev_dbg(pl->netdev,
-		   "%s: mode=%s/%s/%s/%s adv=%*pb pause=%02x link=%u an=%u\n",
-		   __func__, phylink_an_mode_str(pl->link_an_mode),
-		   phy_modes(state->interface),
-		   phy_speed_to_str(state->speed),
-		   phy_duplex_to_str(state->duplex),
-		   __ETHTOOL_LINK_MODE_MASK_NBITS, state->advertising,
-		   state->pause, state->link, state->an_enabled);
-
-	pl->ops->mac_config(pl->netdev, pl->link_an_mode, state);
+	phylink_dbg(pl,
+		    "%s: mode=%s/%s/%s/%s adv=%*pb pause=%02x link=%u an=%u\n",
+		    __func__, phylink_an_mode_str(pl->link_an_mode),
+		    phy_modes(state->interface),
+		    phy_speed_to_str(state->speed),
+		    phy_duplex_to_str(state->duplex),
+		    __ETHTOOL_LINK_MODE_MASK_NBITS, state->advertising,
+		    state->pause, state->link, state->an_enabled);
+
+	pl->ops->mac_config(pl->config, pl->link_an_mode, state);
 }
 
 static void phylink_mac_config_up(struct phylink *pl,
@@ -313,12 +333,11 @@ static void phylink_mac_an_restart(struct phylink *pl)
 {
 	if (pl->link_config.an_enabled &&
 	    phy_interface_mode_is_8023z(pl->link_config.interface))
-		pl->ops->mac_an_restart(pl->netdev);
+		pl->ops->mac_an_restart(pl->config);
 }
 
 static int phylink_get_mac_state(struct phylink *pl, struct phylink_link_state *state)
 {
-	struct net_device *ndev = pl->netdev;
 
 	linkmode_copy(state->advertising, pl->link_config.advertising);
 	linkmode_zero(state->lp_advertising);
@@ -330,7 +349,7 @@ static int phylink_get_mac_state(struct phylink *pl, struct phylink_link_state *
 	state->an_complete = 0;
 	state->link = 1;
 
-	return pl->ops->mac_link_state(ndev, state);
+	return pl->ops->mac_link_state(pl->config, state);
 }
 
 /* The fixed state is... fixed except for the link state,
@@ -395,11 +414,42 @@ static const char *phylink_pause_to_str(int pause)
 	}
 }
 
+static void phylink_mac_link_up(struct phylink *pl,
+				struct phylink_link_state link_state)
+{
+	struct net_device *ndev = pl->netdev;
+
+	pl->ops->mac_link_up(pl->config, pl->link_an_mode,
+			     pl->phy_state.interface,
+			     pl->phydev);
+
+	if (ndev)
+		netif_carrier_on(ndev);
+
+	phylink_info(pl,
+		     "Link is Up - %s/%s - flow control %s\n",
+		     phy_speed_to_str(link_state.speed),
+		     phy_duplex_to_str(link_state.duplex),
+		     phylink_pause_to_str(link_state.pause));
+}
+
+static void phylink_mac_link_down(struct phylink *pl)
+{
+	struct net_device *ndev = pl->netdev;
+
+	if (ndev)
+		netif_carrier_off(ndev);
+	pl->ops->mac_link_down(pl->config, pl->link_an_mode,
+			       pl->phy_state.interface);
+	phylink_info(pl, "Link is Down\n");
+}
+
 static void phylink_resolve(struct work_struct *w)
 {
 	struct phylink *pl = container_of(w, struct phylink, resolve);
 	struct phylink_link_state link_state;
 	struct net_device *ndev = pl->netdev;
+	int link_changed;
 
 	mutex_lock(&pl->state_mutex);
 	if (pl->phylink_disable_state) {
@@ -442,25 +492,17 @@ static void phylink_resolve(struct work_struct *w)
 		}
 	}
 
-	if (link_state.link != netif_carrier_ok(ndev)) {
-		if (!link_state.link) {
-			netif_carrier_off(ndev);
-			pl->ops->mac_link_down(ndev, pl->link_an_mode,
-					       pl->phy_state.interface);
-			netdev_info(ndev, "Link is Down\n");
-		} else {
-			pl->ops->mac_link_up(ndev, pl->link_an_mode,
-					     pl->phy_state.interface,
-					     pl->phydev);
-
-			netif_carrier_on(ndev);
-
-			netdev_info(ndev,
-				    "Link is Up - %s/%s - flow control %s\n",
-				    phy_speed_to_str(link_state.speed),
-				    phy_duplex_to_str(link_state.duplex),
-				    phylink_pause_to_str(link_state.pause));
-		}
+	if (pl->netdev)
+		link_changed = (link_state.link != netif_carrier_ok(ndev));
+	else
+		link_changed = (link_state.link != pl->old_link_state);
+
+	if (link_changed) {
+		pl->old_link_state = link_state.link;
+		if (!link_state.link)
+			phylink_mac_link_down(pl);
+		else
+			phylink_mac_link_up(pl, link_state);
 	}
 	if (!link_state.link && pl->mac_link_dropped) {
 		pl->mac_link_dropped = false;
@@ -512,8 +554,8 @@ static int phylink_register_sfp(struct phylink *pl,
 		if (ret == -ENOENT)
 			return 0;
 
-		netdev_err(pl->netdev, "unable to parse \"sfp\" node: %d\n",
-			   ret);
+		phylink_err(pl, "unable to parse \"sfp\" node: %d\n",
+			    ret);
 		return ret;
 	}
 
@@ -539,7 +581,7 @@ static int phylink_register_sfp(struct phylink *pl,
  * Returns a pointer to a &struct phylink, or an error-pointer value. Users
  * must use IS_ERR() to check for errors from this function.
  */
-struct phylink *phylink_create(struct net_device *ndev,
+struct phylink *phylink_create(struct phylink_config *config,
 			       struct fwnode_handle *fwnode,
 			       phy_interface_t iface,
 			       const struct phylink_mac_ops *ops)
@@ -553,7 +595,17 @@ struct phylink *phylink_create(struct net_device *ndev,
 
 	mutex_init(&pl->state_mutex);
 	INIT_WORK(&pl->resolve, phylink_resolve);
-	pl->netdev = ndev;
+
+	pl->config = config;
+	if (config->type == PHYLINK_NETDEV) {
+		pl->netdev = to_net_dev(config->dev);
+	} else if (config->type == PHYLINK_DEV) {
+		pl->dev = config->dev;
+	} else {
+		kfree(pl);
+		return ERR_PTR(-EINVAL);
+	}
+
 	pl->phy_state.interface = iface;
 	pl->link_interface = iface;
 	if (iface == PHY_INTERFACE_MODE_MOCA)
@@ -635,10 +687,10 @@ static void phylink_phy_change(struct phy_device *phydev, bool up,
 
 	phylink_run_resolve(pl);
 
-	netdev_dbg(pl->netdev, "phy link %s %s/%s/%s\n", up ? "up" : "down",
-		   phy_modes(phydev->interface),
-		   phy_speed_to_str(phydev->speed),
-		   phy_duplex_to_str(phydev->duplex));
+	phylink_dbg(pl, "phy link %s %s/%s/%s\n", up ? "up" : "down",
+		    phy_modes(phydev->interface),
+		    phy_speed_to_str(phydev->speed),
+		    phy_duplex_to_str(phydev->duplex));
 }
 
 static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
@@ -671,9 +723,9 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
 	phy->phylink = pl;
 	phy->phy_link_change = phylink_phy_change;
 
-	netdev_info(pl->netdev,
-		    "PHY [%s] driver [%s]\n", dev_name(&phy->mdio.dev),
-		    phy->drv->name);
+	phylink_info(pl,
+		     "PHY [%s] driver [%s]\n", dev_name(&phy->mdio.dev),
+		     phy->drv->name);
 
 	mutex_lock(&phy->lock);
 	mutex_lock(&pl->state_mutex);
@@ -686,10 +738,10 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
 	mutex_unlock(&pl->state_mutex);
 	mutex_unlock(&phy->lock);
 
-	netdev_dbg(pl->netdev,
-		   "phy: setting supported %*pb advertising %*pb\n",
-		   __ETHTOOL_LINK_MODE_MASK_NBITS, pl->supported,
-		   __ETHTOOL_LINK_MODE_MASK_NBITS, phy->advertising);
+	phylink_dbg(pl,
+		    "phy: setting supported %*pb advertising %*pb\n",
+		    __ETHTOOL_LINK_MODE_MASK_NBITS, pl->supported,
+		    __ETHTOOL_LINK_MODE_MASK_NBITS, phy->advertising);
 
 	if (phy_interrupt_is_valid(phy))
 		phy_request_interrupt(phy);
@@ -867,7 +919,7 @@ void phylink_mac_change(struct phylink *pl, bool up)
 	if (!up)
 		pl->mac_link_dropped = true;
 	phylink_run_resolve(pl);
-	netdev_dbg(pl->netdev, "mac link %s\n", up ? "up" : "down");
+	phylink_dbg(pl, "mac link %s\n", up ? "up" : "down");
 }
 EXPORT_SYMBOL_GPL(phylink_mac_change);
 
@@ -883,12 +935,13 @@ void phylink_start(struct phylink *pl)
 {
 	ASSERT_RTNL();
 
-	netdev_info(pl->netdev, "configuring for %s/%s link mode\n",
-		    phylink_an_mode_str(pl->link_an_mode),
-		    phy_modes(pl->link_config.interface));
+	phylink_info(pl, "configuring for %s/%s link mode\n",
+		     phylink_an_mode_str(pl->link_an_mode),
+		     phy_modes(pl->link_config.interface));
 
 	/* Always set the carrier off */
-	netif_carrier_off(pl->netdev);
+	if (pl->netdev)
+		netif_carrier_off(pl->netdev);
 
 	/* Apply the link configuration to the MAC when starting. This allows
 	 * a fixed-link to start with the correct parameters, and also
@@ -1233,7 +1286,8 @@ int phylink_ethtool_set_pauseparam(struct phylink *pl,
 		switch (pl->link_an_mode) {
 		case MLO_AN_PHY:
 			/* Silently mark the carrier down, and then trigger a resolve */
-			netif_carrier_off(pl->netdev);
+			if (pl->netdev)
+				netif_carrier_off(pl->netdev);
 			phylink_run_resolve(pl);
 			break;
 
@@ -1594,33 +1648,33 @@ static int phylink_sfp_module_insert(void *upstream,
 	/* Ignore errors if we're expecting a PHY to attach later */
 	ret = phylink_validate(pl, support, &config);
 	if (ret) {
-		netdev_err(pl->netdev, "validation with support %*pb failed: %d\n",
-			   __ETHTOOL_LINK_MODE_MASK_NBITS, support, ret);
+		phylink_err(pl, "validation with support %*pb failed: %d\n",
+			    __ETHTOOL_LINK_MODE_MASK_NBITS, support, ret);
 		return ret;
 	}
 
 	iface = sfp_select_interface(pl->sfp_bus, id, config.advertising);
 	if (iface == PHY_INTERFACE_MODE_NA) {
-		netdev_err(pl->netdev,
-			   "selection of interface failed, advertisement %*pb\n",
-			   __ETHTOOL_LINK_MODE_MASK_NBITS, config.advertising);
+		phylink_err(pl,
+			    "selection of interface failed, advertisement %*pb\n",
+			    __ETHTOOL_LINK_MODE_MASK_NBITS, config.advertising);
 		return -EINVAL;
 	}
 
 	config.interface = iface;
 	ret = phylink_validate(pl, support, &config);
 	if (ret) {
-		netdev_err(pl->netdev, "validation of %s/%s with support %*pb failed: %d\n",
-			   phylink_an_mode_str(MLO_AN_INBAND),
-			   phy_modes(config.interface),
-			   __ETHTOOL_LINK_MODE_MASK_NBITS, support, ret);
+		phylink_err(pl, "validation of %s/%s with support %*pb failed: %d\n",
+			    phylink_an_mode_str(MLO_AN_INBAND),
+			    phy_modes(config.interface),
+			    __ETHTOOL_LINK_MODE_MASK_NBITS, support, ret);
 		return ret;
 	}
 
-	netdev_dbg(pl->netdev, "requesting link mode %s/%s with support %*pb\n",
-		   phylink_an_mode_str(MLO_AN_INBAND),
-		   phy_modes(config.interface),
-		   __ETHTOOL_LINK_MODE_MASK_NBITS, support);
+	phylink_dbg(pl, "requesting link mode %s/%s with support %*pb\n",
+		    phylink_an_mode_str(MLO_AN_INBAND),
+		    phy_modes(config.interface),
+		    __ETHTOOL_LINK_MODE_MASK_NBITS, support);
 
 	if (phy_interface_mode_is_8023z(iface) && pl->phydev)
 		return -EINVAL;
@@ -1639,9 +1693,9 @@ static int phylink_sfp_module_insert(void *upstream,
 
 		changed = true;
 
-		netdev_info(pl->netdev, "switched to %s/%s link mode\n",
-			    phylink_an_mode_str(MLO_AN_INBAND),
-			    phy_modes(config.interface));
+		phylink_info(pl, "switched to %s/%s link mode\n",
+			     phylink_an_mode_str(MLO_AN_INBAND),
+			     phy_modes(config.interface));
 	}
 
 	pl->link_port = port;