phylink: add phylink infrastructure

The link between the ethernet MAC and its PHY has become more complex
as the interface evolves.  This is especially true with serdes links,
where the part of the PHY is effectively integrated into the MAC.

Serdes links can be connected to a variety of devices, including SFF
modules soldered down onto the board with the MAC, a SFP cage with
a hotpluggable SFP module which may contain a PHY or directly modulate
the serdes signals onto optical media with or without a PHY, or even
a classical PHY connection.

Moreover, the negotiation information on serdes links comes in two
varieties - SGMII mode, where the PHY provides its speed/duplex/flow
control information to the MAC, and 1000base-X mode where both ends
exchange their abilities and each resolve the link capabilities.

This means we need a more flexible means to support these arrangements,
particularly with the hotpluggable nature of SFP, where the PHY can
be attached or detached after the network device has been brought up.

Ethtool information can come from multiple sources:
- we may have a PHY operating in either SGMII or 1000base-X mode, in
  which case we take ethtool/mii data directly from the PHY.
- we may have a optical SFP module without a PHY, with the MAC
  operating in 1000base-X mode - the ethtool/mii data needs to come
  from the MAC.
- we may have a copper SFP module with a PHY whic can't be accessed,
  which means we need to take ethtool/mii data from the MAC.

Phylink aims to solve this by providing an intermediary between the
MAC and PHY, providing a safe way for PHYs to be hotplugged, and
allowing a SFP driver to reconfigure the serdes connection.

Phylink also takes over support of fixed link connections, where the
speed/duplex/flow control are fixed, but link status may be controlled
by a GPIO signal.  By avoiding the fixed-phy implementation, phylink
can provide a faster response to link events: fixed-phy has to wait for
phylib to operate its state machine, which can take several seconds.
In comparison, phylink takes milliseconds.

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

- remove sync status
- rework supported and advertisment handling
- add 1000base-x speed for fixed links
- use functionality exported from phy-core, reworking
  __phylink_ethtool_ksettings_set for it
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 1181 insertions, 0 deletions

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index a1d6fdba8980..a0a9e03e2f80 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -169,6 +169,16 @@ menuconfig PHYLIB
 	  devices.  This option provides infrastructure for
 	  managing PHY devices.
 
+config PHYLINK
+	tristate
+	depends on NETDEVICES
+	select PHYLIB
+	select SWPHY
+	help
+	  PHYlink models the link between the PHY and MAC, allowing fixed
+	  configuration links, PHYs, and Serdes links with MAC level
+	  autonegotiation modes.
+
 if PHYLIB
 
 config SWPHY
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 113e8d525c5e..c43e5b99fda4 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -18,6 +18,7 @@ endif
 libphy-$(CONFIG_SWPHY)		+= swphy.o
 libphy-$(CONFIG_LED_TRIGGER_PHY)	+= phy_led_triggers.o
 
+obj-$(CONFIG_PHYLINK)		+= phylink.o
 obj-$(CONFIG_PHYLIB)		+= libphy.o
 
 obj-$(CONFIG_MDIO_BCM_IPROC)	+= mdio-bcm-iproc.o
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index d536a9a7cd2b..9493fb369682 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1084,6 +1084,7 @@ void phy_detach(struct phy_device *phydev)
 	phydev->attached_dev->phydev = NULL;
 	phydev->attached_dev = NULL;
 	phy_suspend(phydev);
+	phydev->phylink = NULL;
 
 	phy_led_triggers_unregister(phydev);
 
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
new file mode 100644
index 000000000000..af61d7d400af
--- /dev/null
+++ b/drivers/net/phy/phylink.c
@@ -0,0 +1,1169 @@
+/*
+ * phylink models the MAC to optional PHY connection, supporting
+ * technologies such as SFP cages where the PHY is hot-pluggable.
+ *
+ * Copyright (C) 2015 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/ethtool.h>
+#include <linux/export.h>
+#include <linux/gpio/consumer.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_mdio.h>
+#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>
+
+#include "swphy.h"
+
+#define SUPPORTED_INTERFACES \
+	(SUPPORTED_TP | SUPPORTED_MII | SUPPORTED_FIBRE | \
+	 SUPPORTED_BNC | SUPPORTED_AUI | SUPPORTED_Backplane)
+#define ADVERTISED_INTERFACES \
+	(ADVERTISED_TP | ADVERTISED_MII | ADVERTISED_FIBRE | \
+	 ADVERTISED_BNC | ADVERTISED_AUI | ADVERTISED_Backplane)
+
+enum {
+	PHYLINK_DISABLE_STOPPED,
+};
+
+struct phylink {
+	struct net_device *netdev;
+	const struct phylink_mac_ops *ops;
+
+	unsigned long phylink_disable_state; /* bitmask of disables */
+	struct phy_device *phydev;
+	phy_interface_t link_interface;	/* PHY_INTERFACE_xxx */
+	u8 link_an_mode;		/* MLO_AN_xxx */
+	u8 link_port;			/* The current non-phy ethtool port */
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
+
+	/* The link configuration settings */
+	struct phylink_link_state link_config;
+	struct gpio_desc *link_gpio;
+
+	struct mutex state_mutex;
+	struct phylink_link_state phy_state;
+	struct work_struct resolve;
+
+	bool mac_link_dropped;
+};
+
+static inline void linkmode_zero(unsigned long *dst)
+{
+	bitmap_zero(dst, __ETHTOOL_LINK_MODE_MASK_NBITS);
+}
+
+static inline void linkmode_copy(unsigned long *dst, const unsigned long *src)
+{
+	bitmap_copy(dst, src, __ETHTOOL_LINK_MODE_MASK_NBITS);
+}
+
+static inline void linkmode_and(unsigned long *dst, const unsigned long *a,
+				const unsigned long *b)
+{
+	bitmap_and(dst, a, b, __ETHTOOL_LINK_MODE_MASK_NBITS);
+}
+
+static inline void linkmode_or(unsigned long *dst, const unsigned long *a,
+				const unsigned long *b)
+{
+	bitmap_or(dst, a, b, __ETHTOOL_LINK_MODE_MASK_NBITS);
+}
+
+static inline bool linkmode_empty(const unsigned long *src)
+{
+	return bitmap_empty(src, __ETHTOOL_LINK_MODE_MASK_NBITS);
+}
+
+void phylink_set_port_modes(unsigned long *mask)
+{
+	phylink_set(mask, TP);
+	phylink_set(mask, AUI);
+	phylink_set(mask, MII);
+	phylink_set(mask, FIBRE);
+	phylink_set(mask, BNC);
+	phylink_set(mask, Backplane);
+}
+EXPORT_SYMBOL_GPL(phylink_set_port_modes);
+
+static int phylink_is_empty_linkmode(const unsigned long *linkmode)
+{
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(tmp) = { 0, };
+
+	phylink_set_port_modes(tmp);
+	phylink_set(tmp, Autoneg);
+	phylink_set(tmp, Pause);
+	phylink_set(tmp, Asym_Pause);
+
+	bitmap_andnot(tmp, linkmode, tmp, __ETHTOOL_LINK_MODE_MASK_NBITS);
+
+	return linkmode_empty(tmp);
+}
+
+static const char *phylink_an_mode_str(unsigned int mode)
+{
+	static const char *modestr[] = {
+		[MLO_AN_PHY] = "phy",
+		[MLO_AN_FIXED] = "fixed",
+		[MLO_AN_SGMII] = "SGMII",
+		[MLO_AN_8023Z] = "802.3z",
+	};
+
+	return mode < ARRAY_SIZE(modestr) ? modestr[mode] : "unknown";
+}
+
+static int phylink_validate(struct phylink *pl, unsigned long *supported,
+			    struct phylink_link_state *state)
+{
+	pl->ops->validate(pl->netdev, supported, state);
+
+	return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;
+}
+
+static int phylink_parse_fixedlink(struct phylink *pl, struct device_node *np)
+{
+	struct device_node *fixed_node;
+	const struct phy_setting *s;
+	struct gpio_desc *desc;
+	const __be32 *fixed_prop;
+	u32 speed;
+	int ret, len;
+
+	fixed_node = of_get_child_by_name(np, "fixed-link");
+	if (fixed_node) {
+		ret = of_property_read_u32(fixed_node, "speed", &speed);
+
+		pl->link_config.speed = speed;
+		pl->link_config.duplex = DUPLEX_HALF;
+
+		if (of_property_read_bool(fixed_node, "full-duplex"))
+			pl->link_config.duplex = DUPLEX_FULL;
+
+		/* We treat the "pause" and "asym-pause" terminology as
+		 * defining the link partner's ability. */
+		if (of_property_read_bool(fixed_node, "pause"))
+			pl->link_config.pause |= MLO_PAUSE_SYM;
+		if (of_property_read_bool(fixed_node, "asym-pause"))
+			pl->link_config.pause |= MLO_PAUSE_ASYM;
+
+		if (ret == 0) {
+			desc = fwnode_get_named_gpiod(&fixed_node->fwnode,
+						      "link-gpios", 0,
+						      GPIOD_IN, "?");
+
+			if (!IS_ERR(desc))
+				pl->link_gpio = desc;
+			else if (desc == ERR_PTR(-EPROBE_DEFER))
+				ret = -EPROBE_DEFER;
+		}
+		of_node_put(fixed_node);
+
+		if (ret)
+			return ret;
+	} else {
+		fixed_prop = of_get_property(np, "fixed-link", &len);
+		if (!fixed_prop) {
+			netdev_err(pl->netdev, "broken fixed-link?\n");
+			return -EINVAL;
+		}
+		if (len == 5 * sizeof(*fixed_prop)) {
+			pl->link_config.duplex = be32_to_cpu(fixed_prop[1]) ?
+						DUPLEX_FULL : DUPLEX_HALF;
+			pl->link_config.speed = be32_to_cpu(fixed_prop[2]);
+			if (be32_to_cpu(fixed_prop[3]))
+				pl->link_config.pause |= MLO_PAUSE_SYM;
+			if (be32_to_cpu(fixed_prop[4]))
+				pl->link_config.pause |= MLO_PAUSE_ASYM;
+		}
+	}
+
+	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);
+
+	bitmap_fill(pl->supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
+	linkmode_copy(pl->link_config.advertising, pl->supported);
+	phylink_validate(pl, pl->supported, &pl->link_config);
+
+	s = phy_lookup_setting(pl->link_config.speed, pl->link_config.duplex,
+			       pl->supported,
+			       __ETHTOOL_LINK_MODE_MASK_NBITS, true);
+	linkmode_zero(pl->supported);
+	phylink_set(pl->supported, MII);
+	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);
+	}
+
+	linkmode_and(pl->link_config.advertising, pl->link_config.advertising,
+		     pl->supported);
+
+	pl->link_config.link = 1;
+	pl->link_config.an_complete = 1;
+
+	return 0;
+}
+
+static int phylink_parse_mode(struct phylink *pl, struct device_node *np)
+{
+	struct device_node *dn;
+	const char *managed;
+
+	dn = of_get_child_by_name(np, "fixed-link");
+	if (dn || of_find_property(np, "fixed-link", NULL))
+		pl->link_an_mode = MLO_AN_FIXED;
+	of_node_put(dn);
+
+	if (of_property_read_string(np, "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");
+			return -EINVAL;
+		}
+
+		linkmode_zero(pl->supported);
+		phylink_set(pl->supported, MII);
+		phylink_set(pl->supported, Autoneg);
+		phylink_set(pl->supported, Asym_Pause);
+		phylink_set(pl->supported, Pause);
+		pl->link_config.an_enabled = true;
+
+		switch (pl->link_config.interface) {
+		case PHY_INTERFACE_MODE_SGMII:
+			phylink_set(pl->supported, 10baseT_Half);
+			phylink_set(pl->supported, 10baseT_Full);
+			phylink_set(pl->supported, 100baseT_Half);
+			phylink_set(pl->supported, 100baseT_Full);
+			phylink_set(pl->supported, 1000baseT_Half);
+			phylink_set(pl->supported, 1000baseT_Full);
+			pl->link_an_mode = MLO_AN_SGMII;
+			break;
+
+		case PHY_INTERFACE_MODE_1000BASEX:
+			phylink_set(pl->supported, 1000baseX_Full);
+			pl->link_an_mode = MLO_AN_8023Z;
+			break;
+
+		case PHY_INTERFACE_MODE_2500BASEX:
+			phylink_set(pl->supported, 2500baseX_Full);
+			pl->link_an_mode = MLO_AN_8023Z;
+			break;
+
+		default:
+			netdev_err(pl->netdev,
+				   "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");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+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);
+}
+
+static void phylink_mac_an_restart(struct phylink *pl)
+{
+	if (pl->link_config.an_enabled &&
+	    (pl->link_config.interface == PHY_INTERFACE_MODE_1000BASEX ||
+	     pl->link_config.interface == PHY_INTERFACE_MODE_2500BASEX))
+		pl->ops->mac_an_restart(pl->netdev);
+}
+
+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);
+	state->interface = pl->link_config.interface;
+	state->an_enabled = pl->link_config.an_enabled;
+	state->link = 1;
+
+	return pl->ops->mac_link_state(ndev, state);
+}
+
+/* The fixed state is... fixed except for the link state,
+ * which may be determined by a GPIO.
+ */
+static void phylink_get_fixed_state(struct phylink *pl, struct phylink_link_state *state)
+{
+	*state = pl->link_config;
+	if (pl->link_gpio)
+		state->link = !!gpiod_get_value(pl->link_gpio);
+}
+
+/* Flow control is resolved according to our and the link partners
+ * advertisments using the following drawn from the 802.3 specs:
+ *  Local device  Link partner
+ *  Pause AsymDir Pause AsymDir Result
+ *    1     X       1     X     TX+RX
+ *    0     1       1     1     RX
+ *    1     1       0     1     TX
+ */
+static void phylink_resolve_flow(struct phylink *pl,
+	struct phylink_link_state *state)
+{
+	int new_pause = 0;
+
+	if (pl->link_config.pause & MLO_PAUSE_AN) {
+		int pause = 0;
+
+		if (phylink_test(pl->link_config.advertising, Pause))
+			pause |= MLO_PAUSE_SYM;
+		if (phylink_test(pl->link_config.advertising, Asym_Pause))
+			pause |= MLO_PAUSE_ASYM;
+
+		pause &= state->pause;
+
+		if (pause & MLO_PAUSE_SYM)
+			new_pause = MLO_PAUSE_TX | MLO_PAUSE_RX;
+		else if (pause & MLO_PAUSE_ASYM)
+			new_pause = state->pause & MLO_PAUSE_SYM ?
+				 MLO_PAUSE_RX : MLO_PAUSE_TX;
+	} else {
+		new_pause = pl->link_config.pause & MLO_PAUSE_TXRX_MASK;
+	}
+
+	state->pause &= ~MLO_PAUSE_TXRX_MASK;
+	state->pause |= new_pause;
+}
+
+static const char *phylink_pause_to_str(int pause)
+{
+	switch (pause & MLO_PAUSE_TXRX_MASK) {
+	case MLO_PAUSE_TX | MLO_PAUSE_RX:
+		return "rx/tx";
+	case MLO_PAUSE_TX:
+		return "tx";
+	case MLO_PAUSE_RX:
+		return "rx";
+	default:
+		return "off";
+	}
+}
+
+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;
+
+	mutex_lock(&pl->state_mutex);
+	if (pl->phylink_disable_state) {
+		pl->mac_link_dropped = false;
+		link_state.link = false;
+	} else if (pl->mac_link_dropped) {
+		link_state.link = false;
+	} else {
+		switch (pl->link_an_mode) {
+		case MLO_AN_PHY:
+			link_state = pl->phy_state;
+			phylink_resolve_flow(pl, &link_state);
+			phylink_mac_config(pl, &link_state);
+			break;
+
+		case MLO_AN_FIXED:
+			phylink_get_fixed_state(pl, &link_state);
+			phylink_mac_config(pl, &link_state);
+			break;
+
+		case MLO_AN_SGMII:
+			phylink_get_mac_state(pl, &link_state);
+			if (pl->phydev) {
+				bool changed = false;
+
+				link_state.link = link_state.link &&
+						  pl->phy_state.link;
+
+				if (pl->phy_state.interface !=
+				    link_state.interface) {
+					link_state.interface = pl->phy_state.interface;
+					changed = true;
+				}
+
+				/* Propagate the flow control from the PHY
+				 * to the MAC. Also propagate the interface
+				 * if changed.
+				 */
+				if (pl->phy_state.link || changed) {
+					link_state.pause |= pl->phy_state.pause;
+					phylink_resolve_flow(pl, &link_state);
+
+					phylink_mac_config(pl, &link_state);
+				}
+			}
+			break;
+
+		case MLO_AN_8023Z:
+			phylink_get_mac_state(pl, &link_state);
+			break;
+		}
+	}
+
+	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);
+			netdev_info(ndev, "Link is Down\n");
+		} else {
+			pl->ops->mac_link_up(ndev, pl->link_an_mode,
+					     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 (!link_state.link && pl->mac_link_dropped) {
+		pl->mac_link_dropped = false;
+		queue_work(system_power_efficient_wq, &pl->resolve);
+	}
+	mutex_unlock(&pl->state_mutex);
+}
+
+static void phylink_run_resolve(struct phylink *pl)
+{
+	if (!pl->phylink_disable_state)
+		queue_work(system_power_efficient_wq, &pl->resolve);
+}
+
+struct phylink *phylink_create(struct net_device *ndev, struct device_node *np,
+	phy_interface_t iface, const struct phylink_mac_ops *ops)
+{
+	struct phylink *pl;
+	int ret;
+
+	pl = kzalloc(sizeof(*pl), GFP_KERNEL);
+	if (!pl)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&pl->state_mutex);
+	INIT_WORK(&pl->resolve, phylink_resolve);
+	pl->netdev = ndev;
+	pl->phy_state.interface = iface;
+	pl->link_interface = iface;
+	pl->link_port = PORT_MII;
+	pl->link_config.interface = iface;
+	pl->link_config.pause = MLO_PAUSE_AN;
+	pl->link_config.speed = SPEED_UNKNOWN;
+	pl->link_config.duplex = DUPLEX_UNKNOWN;
+	pl->ops = ops;
+	__set_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
+
+	bitmap_fill(pl->supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
+	linkmode_copy(pl->link_config.advertising, pl->supported);
+	phylink_validate(pl, pl->supported, &pl->link_config);
+
+	ret = phylink_parse_mode(pl, np);
+	if (ret < 0) {
+		kfree(pl);
+		return ERR_PTR(ret);
+	}
+
+	if (pl->link_an_mode == MLO_AN_FIXED) {
+		ret = phylink_parse_fixedlink(pl, np);
+		if (ret < 0) {
+			kfree(pl);
+			return ERR_PTR(ret);
+		}
+	}
+
+	return pl;
+}
+EXPORT_SYMBOL_GPL(phylink_create);
+
+void phylink_destroy(struct phylink *pl)
+{
+	cancel_work_sync(&pl->resolve);
+	kfree(pl);
+}
+EXPORT_SYMBOL_GPL(phylink_destroy);
+
+void phylink_phy_change(struct phy_device *phydev, bool up, bool do_carrier)
+{
+	struct phylink *pl = phydev->phylink;
+
+	mutex_lock(&pl->state_mutex);
+	pl->phy_state.speed = phydev->speed;
+	pl->phy_state.duplex = phydev->duplex;
+	pl->phy_state.pause = MLO_PAUSE_NONE;
+	if (phydev->pause)
+		pl->phy_state.pause |= MLO_PAUSE_SYM;
+	if (phydev->asym_pause)
+		pl->phy_state.pause |= MLO_PAUSE_ASYM;
+	pl->phy_state.interface = phydev->interface;
+	pl->phy_state.link = up;
+	mutex_unlock(&pl->state_mutex);
+
+	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));
+}
+
+static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
+{
+	struct phylink_link_state config;
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
+	u32 advertising;
+	int ret;
+
+	memset(&config, 0, sizeof(config));
+	ethtool_convert_legacy_u32_to_link_mode(supported, phy->supported);
+	ethtool_convert_legacy_u32_to_link_mode(config.advertising,
+						phy->advertising);
+	config.interface = pl->link_config.interface;
+
+	/*
+	 * This is the new way of dealing with flow control for PHYs,
+	 * as described by Timur Tabi in commit 529ed1275263 ("net: phy:
+	 * phy drivers should not set SUPPORTED_[Asym_]Pause") except
+	 * using our validate call to the MAC, we rely upon the MAC
+	 * clearing the bits from both supported and advertising fields.
+	 */
+	if (phylink_test(supported, Pause))
+		phylink_set(config.advertising, Pause);
+	if (phylink_test(supported, Asym_Pause))
+		phylink_set(config.advertising, Asym_Pause);
+
+	ret = phylink_validate(pl, supported, &config);
+	if (ret)
+		return ret;
+
+	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);
+
+	mutex_lock(&phy->lock);
+	mutex_lock(&pl->state_mutex);
+	pl->netdev->phydev = phy;
+	pl->phydev = phy;
+	linkmode_copy(pl->supported, supported);
+	linkmode_copy(pl->link_config.advertising, config.advertising);
+
+	/* Restrict the phy advertisment according to the MAC support. */
+	ethtool_convert_link_mode_to_legacy_u32(&advertising, config.advertising);
+	phy->advertising = advertising;
+	mutex_unlock(&pl->state_mutex);
+	mutex_unlock(&phy->lock);
+
+	netdev_dbg(pl->netdev,
+		   "phy: setting supported %*pb advertising 0x%08x\n",
+		   __ETHTOOL_LINK_MODE_MASK_NBITS, pl->supported,
+		   phy->advertising);
+
+	phy_start_machine(phy);
+	if (phy->irq > 0)
+		phy_start_interrupts(phy);
+
+	return 0;
+}
+
+int phylink_connect_phy(struct phylink *pl, struct phy_device *phy)
+{
+	int ret;
+
+	ret = phy_attach_direct(pl->netdev, phy, 0, pl->link_interface);
+	if (ret)
+		return ret;
+
+	ret = phylink_bringup_phy(pl, phy);
+	if (ret)
+		phy_detach(phy);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_connect_phy);
+
+int phylink_of_phy_connect(struct phylink *pl, struct device_node *dn)
+{
+	struct device_node *phy_node;
+	struct phy_device *phy_dev;
+	int ret;
+
+	/* Fixed links are handled without needing a PHY */
+	if (pl->link_an_mode == MLO_AN_FIXED)
+		return 0;
+
+	phy_node = of_parse_phandle(dn, "phy-handle", 0);
+	if (!phy_node)
+		phy_node = of_parse_phandle(dn, "phy", 0);
+	if (!phy_node)
+		phy_node = of_parse_phandle(dn, "phy-device", 0);
+
+	if (!phy_node) {
+		if (pl->link_an_mode == MLO_AN_PHY) {
+			netdev_err(pl->netdev, "unable to find PHY node\n");
+			return -ENODEV;
+		}
+		return 0;
+	}
+
+	phy_dev = of_phy_attach(pl->netdev, phy_node, 0, pl->link_interface);
+	/* We're done with the phy_node handle */
+	of_node_put(phy_node);
+
+	if (!phy_dev)
+		return -ENODEV;
+
+	ret = phylink_bringup_phy(pl, phy_dev);
+	if (ret)
+		phy_detach(phy_dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_of_phy_connect);
+
+void phylink_disconnect_phy(struct phylink *pl)
+{
+	struct phy_device *phy;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	phy = pl->phydev;
+	if (phy) {
+		mutex_lock(&phy->lock);
+		mutex_lock(&pl->state_mutex);
+		pl->netdev->phydev = NULL;
+		pl->phydev = NULL;
+		mutex_unlock(&pl->state_mutex);
+		mutex_unlock(&phy->lock);
+		flush_work(&pl->resolve);
+
+		phy_disconnect(phy);
+	}
+}
+EXPORT_SYMBOL_GPL(phylink_disconnect_phy);
+
+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");
+}
+EXPORT_SYMBOL_GPL(phylink_mac_change);
+
+void phylink_start(struct phylink *pl)
+{
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	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));
+
+	/* Apply the link configuration to the MAC when starting. This allows
+	 * a fixed-link to start with the correct parameters, and also
+	 * ensures that we set the appropriate advertisment for Serdes links.
+	 */
+	phylink_resolve_flow(pl, &pl->link_config);
+	phylink_mac_config(pl, &pl->link_config);
+
+	clear_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
+	phylink_run_resolve(pl);
+
+	if (pl->phydev)
+		phy_start(pl->phydev);
+}
+EXPORT_SYMBOL_GPL(phylink_start);
+
+void phylink_stop(struct phylink *pl)
+{
+	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);
+}
+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;
+
+	if (pl->phydev)
+		phy_ethtool_get_wol(pl->phydev, wol);
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_get_wol);
+
+int phylink_ethtool_set_wol(struct phylink *pl, struct ethtool_wolinfo *wol)
+{
+	int ret = -EOPNOTSUPP;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (pl->phydev)
+		ret = phy_ethtool_set_wol(pl->phydev, wol);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_set_wol);
+
+static void phylink_merge_link_mode(unsigned long *dst, const unsigned long *b)
+{
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask);
+
+	linkmode_zero(mask);
+	phylink_set_port_modes(mask);
+
+	linkmode_and(dst, dst, mask);
+	linkmode_or(dst, dst, b);
+}
+
+static void phylink_get_ksettings(const struct phylink_link_state *state,
+				  struct ethtool_link_ksettings *kset)
+{
+	phylink_merge_link_mode(kset->link_modes.advertising, state->advertising);
+	linkmode_copy(kset->link_modes.lp_advertising, state->lp_advertising);
+	kset->base.speed = state->speed;
+	kset->base.duplex = state->duplex;
+	kset->base.autoneg = state->an_enabled ? AUTONEG_ENABLE :
+				AUTONEG_DISABLE;
+}
+
+int phylink_ethtool_ksettings_get(struct phylink *pl,
+	struct ethtool_link_ksettings *kset)
+{
+	struct phylink_link_state link_state;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (pl->phydev) {
+		phy_ethtool_ksettings_get(pl->phydev, kset);
+	} else {
+		kset->base.port = pl->link_port;
+	}
+
+	linkmode_copy(kset->link_modes.supported, pl->supported);
+
+	switch (pl->link_an_mode) {
+	case MLO_AN_FIXED:
+		/* We are using fixed settings. Report these as the
+		 * current link settings - and note that these also
+		 * represent the supported speeds/duplex/pause modes.
+		 */
+		phylink_get_fixed_state(pl, &link_state);
+		phylink_get_ksettings(&link_state, kset);
+		break;
+
+	case MLO_AN_SGMII:
+		/* If there is a phy attached, then use the reported
+		 * settings from the phy with no modification.
+		 */
+		if (pl->phydev)
+			break;
+
+	case MLO_AN_8023Z:
+		phylink_get_mac_state(pl, &link_state);
+
+		/* The MAC is reporting the link results from its own PCS
+		 * layer via in-band status. Report these as the current
+		 * link settings.
+		 */
+		phylink_get_ksettings(&link_state, kset);
+		break;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_ksettings_get);
+
+int phylink_ethtool_ksettings_set(struct phylink *pl,
+	const struct ethtool_link_ksettings *kset)
+{
+	struct ethtool_link_ksettings our_kset;
+	struct phylink_link_state config;
+	int ret;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (kset->base.autoneg != AUTONEG_DISABLE &&
+	    kset->base.autoneg != AUTONEG_ENABLE)
+		return -EINVAL;
+
+	config = pl->link_config;
+
+	/* Mask out unsupported advertisments */
+	linkmode_and(config.advertising, kset->link_modes.advertising,
+		     pl->supported);
+
+	/* FIXME: should we reject autoneg if phy/mac does not support it? */
+	if (kset->base.autoneg == AUTONEG_DISABLE) {
+		const struct phy_setting *s;
+
+		/* Autonegotiation disabled, select a suitable speed and
+		 * duplex.
+		 */
+		s = phy_lookup_setting(kset->base.speed, kset->base.duplex,
+				       pl->supported,
+				       __ETHTOOL_LINK_MODE_MASK_NBITS, false);
+		if (!s)
+			return -EINVAL;
+
+		/* If we have a fixed link (as specified by firmware), refuse
+		 * to change link parameters.
+		 */
+		if (pl->link_an_mode == MLO_AN_FIXED &&
+		    (s->speed != pl->link_config.speed ||
+		     s->duplex != pl->link_config.duplex))
+			return -EINVAL;
+
+		config.speed = s->speed;
+		config.duplex = s->duplex;
+		config.an_enabled = false;
+
+		__clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, config.advertising);
+	} else {
+		/* If we have a fixed link, refuse to enable autonegotiation */
+		if (pl->link_an_mode == MLO_AN_FIXED)
+			return -EINVAL;
+
+		config.speed = SPEED_UNKNOWN;
+		config.duplex = DUPLEX_UNKNOWN;
+		config.an_enabled = true;
+
+		__set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, config.advertising);
+	}
+
+	if (phylink_validate(pl, pl->supported, &config))
+		return -EINVAL;
+
+	/* If autonegotiation is enabled, we must have an advertisment */
+	if (config.an_enabled && phylink_is_empty_linkmode(config.advertising))
+		return -EINVAL;
+
+	our_kset = *kset;
+	linkmode_copy(our_kset.link_modes.advertising, config.advertising);
+	our_kset.base.speed = config.speed;
+	our_kset.base.duplex = config.duplex;
+
+	/* If we have a PHY, configure the phy */
+	if (pl->phydev) {
+		ret = phy_ethtool_ksettings_set(pl->phydev, &our_kset);
+		if (ret)
+			return ret;
+	}
+
+	mutex_lock(&pl->state_mutex);
+	/* Configure the MAC to match the new settings */
+	linkmode_copy(pl->link_config.advertising, our_kset.link_modes.advertising);
+	pl->link_config.speed = our_kset.base.speed;
+	pl->link_config.duplex = our_kset.base.duplex;
+	pl->link_config.an_enabled = our_kset.base.autoneg != AUTONEG_DISABLE;
+
+	if (!test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state)) {
+		phylink_mac_config(pl, &pl->link_config);
+		phylink_mac_an_restart(pl);
+	}
+	mutex_unlock(&pl->state_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_ksettings_set);
+
+int phylink_ethtool_nway_reset(struct phylink *pl)
+{
+	int ret = 0;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (pl->phydev)
+		ret = phy_restart_aneg(pl->phydev);
+	phylink_mac_an_restart(pl);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_nway_reset);
+
+void phylink_ethtool_get_pauseparam(struct phylink *pl,
+				    struct ethtool_pauseparam *pause)
+{
+	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);
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_get_pauseparam);
+
+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;
+
+	if (!phylink_test(pl->supported, Asym_Pause) &&
+	    !pause->autoneg && pause->rx_pause != pause->tx_pause)
+		return -EINVAL;
+
+	config->pause &= ~(MLO_PAUSE_AN | MLO_PAUSE_TXRX_MASK);
+
+	if (pause->autoneg)
+		config->pause |= MLO_PAUSE_AN;
+	if (pause->rx_pause)
+		config->pause |= MLO_PAUSE_RX;
+	if (pause->tx_pause)
+		config->pause |= MLO_PAUSE_TX;
+
+	if (!test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state)) {
+		switch (pl->link_an_mode) {
+		case MLO_AN_PHY:
+			/* Silently mark the carrier down, and then trigger a resolve */
+			netif_carrier_off(pl->netdev);
+			phylink_run_resolve(pl);
+			break;
+
+		case MLO_AN_FIXED:
+			/* Should we allow fixed links to change against the config? */
+			phylink_resolve_flow(pl, config);
+			phylink_mac_config(pl, config);
+			break;
+
+		case MLO_AN_SGMII:
+		case MLO_AN_8023Z:
+			phylink_mac_config(pl, config);
+			phylink_mac_an_restart(pl);
+			break;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_set_pauseparam);
+
+int phylink_init_eee(struct phylink *pl, bool clk_stop_enable)
+{
+	int ret = -EPROTONOSUPPORT;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (pl->phydev)
+		ret = phy_init_eee(pl->phydev, clk_stop_enable);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_init_eee);
+
+int phylink_get_eee_err(struct phylink *pl)
+{
+	int ret = 0;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (pl->phydev)
+		ret = phy_get_eee_err(pl->phydev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_get_eee_err);
+
+int phylink_ethtool_get_eee(struct phylink *pl, struct ethtool_eee *eee)
+{
+	int ret = -EOPNOTSUPP;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (pl->phydev)
+		ret = phy_ethtool_get_eee(pl->phydev, eee);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_get_eee);
+
+int phylink_ethtool_set_eee(struct phylink *pl, struct ethtool_eee *eee)
+{
+	int ret = -EOPNOTSUPP;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	if (pl->phydev)
+		ret = phy_ethtool_set_eee(pl->phydev, eee);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_ethtool_set_eee);
+
+/* This emulates MII registers for a fixed-mode phy operating as per the
+ * passed in state. "aneg" defines if we report negotiation is possible.
+ *
+ * FIXME: should deal with negotiation state too.
+ */
+static int phylink_mii_emul_read(struct net_device *ndev, unsigned int reg,
+				 struct phylink_link_state *state, bool aneg)
+{
+	struct fixed_phy_status fs;
+	int val;
+
+	fs.link = state->link;
+	fs.speed = state->speed;
+	fs.duplex = state->duplex;
+	fs.pause = state->pause & MLO_PAUSE_SYM;
+	fs.asym_pause = state->pause & MLO_PAUSE_ASYM;
+
+	val = swphy_read_reg(reg, &fs);
+	if (reg == MII_BMSR) {
+		if (!state->an_complete)
+			val &= ~BMSR_ANEGCOMPLETE;
+		if (!aneg)
+			val &= ~BMSR_ANEGCAPABLE;
+	}
+	return val;
+}
+
+static int phylink_mii_read(struct phylink *pl, unsigned int phy_id,
+			    unsigned int reg)
+{
+	struct phylink_link_state state;
+	int val = 0xffff;
+
+	/* PHYs only exist for MLO_AN_PHY and MLO_AN_SGMII */
+	if (pl->phydev)
+		return mdiobus_read(pl->phydev->mdio.bus, phy_id, reg);
+
+	switch (pl->link_an_mode) {
+	case MLO_AN_FIXED:
+		if (phy_id == 0) {
+			phylink_get_fixed_state(pl, &state);
+			val = phylink_mii_emul_read(pl->netdev, reg, &state,
+						    true);
+		}
+		break;
+
+	case MLO_AN_PHY:
+		return -EOPNOTSUPP;
+
+	case MLO_AN_SGMII:
+		/* No phy, fall through to 8023z method */
+	case MLO_AN_8023Z:
+		if (phy_id == 0) {
+			val = phylink_get_mac_state(pl, &state);
+			if (val < 0)
+				return val;
+
+			val = phylink_mii_emul_read(pl->netdev, reg, &state,
+						    true);
+		}
+		break;
+	}
+
+	return val & 0xffff;
+}
+
+static int phylink_mii_write(struct phylink *pl, unsigned int phy_id,
+			     unsigned int reg, unsigned int val)
+{
+	/* PHYs only exist for MLO_AN_PHY and MLO_AN_SGMII */
+	if (pl->phydev) {
+		mdiobus_write(pl->phydev->mdio.bus, phy_id, reg, val);
+		return 0;
+	}
+
+	switch (pl->link_an_mode) {
+	case MLO_AN_FIXED:
+		break;
+
+	case MLO_AN_PHY:
+		return -EOPNOTSUPP;
+
+	case MLO_AN_SGMII:
+		/* No phy, fall through to 8023z method */
+	case MLO_AN_8023Z:
+		break;
+	}
+
+	return 0;
+}
+
+int phylink_mii_ioctl(struct phylink *pl, struct ifreq *ifr, int cmd)
+{
+	struct mii_ioctl_data *mii_data = if_mii(ifr);
+	int val, ret;
+
+	WARN_ON(!lockdep_rtnl_is_held());
+
+	switch (cmd) {
+	case SIOCGMIIPHY:
+		mii_data->phy_id = pl->phydev ? pl->phydev->mdio.addr : 0;
+		/* fallthrough */
+
+	case SIOCGMIIREG:
+		val = phylink_mii_read(pl, mii_data->phy_id, mii_data->reg_num);
+		if (val < 0) {
+			ret = val;
+		} else {
+			mii_data->val_out = val;
+			ret = 0;
+		}
+		break;
+
+	case SIOCSMIIREG:
+		ret = phylink_mii_write(pl, mii_data->phy_id, mii_data->reg_num,
+					mii_data->val_in);
+		break;
+
+	default:
+		ret = -EOPNOTSUPP;
+		if (pl->phydev)
+			ret = phy_mii_ioctl(pl->phydev, ifr, cmd);
+		break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phylink_mii_ioctl);
+
+MODULE_LICENSE("GPL");