phylink.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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
 */
#include <linux/acpi.h>
#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/timer.h>
#include <linux/workqueue.h>

#include "sfp.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,
	PHYLINK_DISABLE_LINK,
	PHYLINK_DISABLE_MAC_WOL,
};

/**
 * struct phylink - internal data type for phylink
 */
struct phylink {
	/* private: */
	struct net_device *netdev;
	const struct phylink_mac_ops *mac_ops;
	const struct phylink_pcs_ops *pcs_ops;
	struct phylink_config *config;
	struct phylink_pcs *pcs;
	struct device *dev;
	unsigned int old_link_state:1;

	unsigned long phylink_disable_state; /* bitmask of disables */
	struct phy_device *phydev;
	phy_interface_t link_interface;	/* PHY_INTERFACE_xxx */
	u8 cfg_link_an_mode;		/* MLO_AN_xxx */
	u8 cur_link_an_mode;
	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;

	/* The current settings */
	phy_interface_t cur_interface;

	struct gpio_desc *link_gpio;
	unsigned int link_irq;
	struct timer_list link_poll;
	void (*get_fixed_state)(struct net_device *dev,
				struct phylink_link_state *s);

	struct mutex state_mutex;
	struct phylink_link_state phy_state;
	struct work_struct resolve;

	bool mac_link_dropped;

	struct sfp_bus *sfp_bus;
	bool sfp_may_have_phy;
	__ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support);
	u8 sfp_port;
};

#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__)
#if defined(CONFIG_DYNAMIC_DEBUG)
#define phylink_dbg(pl, fmt, ...) \
do {									\
	if ((pl)->config->type == PHYLINK_NETDEV)			\
		netdev_dbg((pl)->netdev, fmt, ##__VA_ARGS__);		\
	else if ((pl)->config->type == PHYLINK_DEV)			\
		dev_dbg((pl)->dev, fmt, ##__VA_ARGS__);			\
} while (0)
#elif defined(DEBUG)
#define phylink_dbg(pl, fmt, ...)					\
	phylink_printk(KERN_DEBUG, pl, fmt, ##__VA_ARGS__)
#else
#define phylink_dbg(pl, fmt, ...)					\
({									\
	if (0)								\
		phylink_printk(KERN_DEBUG, pl, fmt, ##__VA_ARGS__);	\
})
#endif

/**
 * phylink_set_port_modes() - set the port type modes in the ethtool mask
 * @mask: ethtool link mode mask
 *
 * Sets all the port type modes in the ethtool mask.  MAC drivers should
 * use this in their 'validate' callback.
 */
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);

void phylink_set_10g_modes(unsigned long *mask)
{
	phylink_set(mask, 10000baseT_Full);
	phylink_set(mask, 10000baseCR_Full);
	phylink_set(mask, 10000baseSR_Full);
	phylink_set(mask, 10000baseLR_Full);
	phylink_set(mask, 10000baseLRM_Full);
	phylink_set(mask, 10000baseER_Full);
}
EXPORT_SYMBOL_GPL(phylink_set_10g_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);

	return linkmode_subset(linkmode, 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_INBAND] = "inband",
	};

	return mode < ARRAY_SIZE(modestr) ? modestr[mode] : "unknown";
}

static int phylink_validate_any(struct phylink *pl, unsigned long *supported,
				struct phylink_link_state *state)
{
	__ETHTOOL_DECLARE_LINK_MODE_MASK(all_adv) = { 0, };
	__ETHTOOL_DECLARE_LINK_MODE_MASK(all_s) = { 0, };
	__ETHTOOL_DECLARE_LINK_MODE_MASK(s);
	struct phylink_link_state t;
	int intf;

	for (intf = 0; intf < PHY_INTERFACE_MODE_MAX; intf++) {
		if (test_bit(intf, pl->config->supported_interfaces)) {
			linkmode_copy(s, supported);

			t = *state;
			t.interface = intf;
			pl->mac_ops->validate(pl->config, s, &t);
			linkmode_or(all_s, all_s, s);
			linkmode_or(all_adv, all_adv, t.advertising);
		}
	}

	linkmode_copy(supported, all_s);
	linkmode_copy(state->advertising, all_adv);

	return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;
}

static int phylink_validate(struct phylink *pl, unsigned long *supported,
			    struct phylink_link_state *state)
{
	if (!phy_interface_empty(pl->config->supported_interfaces)) {
		if (state->interface == PHY_INTERFACE_MODE_NA)
			return phylink_validate_any(pl, supported, state);

		if (!test_bit(state->interface,
			      pl->config->supported_interfaces))
			return -EINVAL;
	}

	pl->mac_ops->validate(pl->config, supported, state);

	return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;
}

static int phylink_parse_fixedlink(struct phylink *pl,
				   struct fwnode_handle *fwnode)
{
	struct fwnode_handle *fixed_node;
	const struct phy_setting *s;
	struct gpio_desc *desc;
	u32 speed;
	int ret;

	fixed_node = fwnode_get_named_child_node(fwnode, "fixed-link");
	if (fixed_node) {
		ret = fwnode_property_read_u32(fixed_node, "speed", &speed);

		pl->link_config.speed = speed;
		pl->link_config.duplex = DUPLEX_HALF;

		if (fwnode_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 (fwnode_property_read_bool(fixed_node, "pause"))
			__set_bit(ETHTOOL_LINK_MODE_Pause_BIT,
				  pl->link_config.lp_advertising);
		if (fwnode_property_read_bool(fixed_node, "asym-pause"))
			__set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
				  pl->link_config.lp_advertising);

		if (ret == 0) {
			desc = fwnode_gpiod_get_index(fixed_node, "link", 0,
						      GPIOD_IN, "?");

			if (!IS_ERR(desc))
				pl->link_gpio = desc;
			else if (desc == ERR_PTR(-EPROBE_DEFER))
				ret = -EPROBE_DEFER;
		}
		fwnode_handle_put(fixed_node);

		if (ret)
			return ret;
	} else {
		u32 prop[5];

		ret = fwnode_property_read_u32_array(fwnode, "fixed-link",
						     NULL, 0);
		if (ret != ARRAY_SIZE(prop)) {
			phylink_err(pl, "broken fixed-link?\n");
			return -EINVAL;
		}

		ret = fwnode_property_read_u32_array(fwnode, "fixed-link",
						     prop, ARRAY_SIZE(prop));
		if (!ret) {
			pl->link_config.duplex = prop[1] ?
						DUPLEX_FULL : DUPLEX_HALF;
			pl->link_config.speed = prop[2];
			if (prop[3])
				__set_bit(ETHTOOL_LINK_MODE_Pause_BIT,
					  pl->link_config.lp_advertising);
			if (prop[4])
				__set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
					  pl->link_config.lp_advertising);
		}
	}

	if (pl->link_config.speed > SPEED_1000 &&
	    pl->link_config.duplex != DUPLEX_FULL)
		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);
	phylink_validate(pl, pl->supported, &pl->link_config);

	s = phy_lookup_setting(pl->link_config.speed, pl->link_config.duplex,
			       pl->supported, true);
	linkmode_zero(pl->supported);
	phylink_set(pl->supported, MII);
	phylink_set(pl->supported, Pause);
	phylink_set(pl->supported, Asym_Pause);
	phylink_set(pl->supported, Autoneg);
	if (s) {
		__set_bit(s->bit, pl->supported);
		__set_bit(s->bit, pl->link_config.lp_advertising);
	} else {
		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,
		     pl->supported);

	pl->link_config.link = 1;
	pl->link_config.an_complete = 1;

	return 0;
}

static int phylink_parse_mode(struct phylink *pl, struct fwnode_handle *fwnode)
{
	struct fwnode_handle *dn;
	const char *managed;

	dn = fwnode_get_named_child_node(fwnode, "fixed-link");
	if (dn || fwnode_property_present(fwnode, "fixed-link"))
		pl->cfg_link_an_mode = MLO_AN_FIXED;
	fwnode_handle_put(dn);

	if ((fwnode_property_read_string(fwnode, "managed", &managed) == 0 &&
	     strcmp(managed, "in-band-status") == 0) ||
	    pl->config->ovr_an_inband) {
		if (pl->cfg_link_an_mode == MLO_AN_FIXED) {
			phylink_err(pl,
				    "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;
		pl->cfg_link_an_mode = MLO_AN_INBAND;

		switch (pl->link_config.interface) {
		case PHY_INTERFACE_MODE_SGMII:
		case PHY_INTERFACE_MODE_QSGMII:
			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);
			break;

		case PHY_INTERFACE_MODE_1000BASEX:
			phylink_set(pl->supported, 1000baseX_Full);
			break;

		case PHY_INTERFACE_MODE_2500BASEX:
			phylink_set(pl->supported, 2500baseX_Full);
			break;

		case PHY_INTERFACE_MODE_5GBASER:
			phylink_set(pl->supported, 5000baseT_Full);
			break;

		case PHY_INTERFACE_MODE_25GBASER:
			phylink_set(pl->supported, 25000baseCR_Full);
			phylink_set(pl->supported, 25000baseKR_Full);
			phylink_set(pl->supported, 25000baseSR_Full);
			fallthrough;
		case PHY_INTERFACE_MODE_USXGMII:
		case PHY_INTERFACE_MODE_10GKR:
		case PHY_INTERFACE_MODE_10GBASER:
			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);
			phylink_set(pl->supported, 1000baseX_Full);
			phylink_set(pl->supported, 1000baseKX_Full);
			phylink_set(pl->supported, 2500baseT_Full);
			phylink_set(pl->supported, 2500baseX_Full);
			phylink_set(pl->supported, 5000baseT_Full);
			phylink_set(pl->supported, 10000baseT_Full);
			phylink_set(pl->supported, 10000baseKR_Full);
			phylink_set(pl->supported, 10000baseKX4_Full);
			phylink_set(pl->supported, 10000baseCR_Full);
			phylink_set(pl->supported, 10000baseSR_Full);
			phylink_set(pl->supported, 10000baseLR_Full);
			phylink_set(pl->supported, 10000baseLRM_Full);
			phylink_set(pl->supported, 10000baseER_Full);
			break;

		case PHY_INTERFACE_MODE_XLGMII:
			phylink_set(pl->supported, 25000baseCR_Full);
			phylink_set(pl->supported, 25000baseKR_Full);
			phylink_set(pl->supported, 25000baseSR_Full);
			phylink_set(pl->supported, 40000baseKR4_Full);
			phylink_set(pl->supported, 40000baseCR4_Full);
			phylink_set(pl->supported, 40000baseSR4_Full);
			phylink_set(pl->supported, 40000baseLR4_Full);
			phylink_set(pl->supported, 50000baseCR2_Full);
			phylink_set(pl->supported, 50000baseKR2_Full);
			phylink_set(pl->supported, 50000baseSR2_Full);
			phylink_set(pl->supported, 50000baseKR_Full);
			phylink_set(pl->supported, 50000baseSR_Full);
			phylink_set(pl->supported, 50000baseCR_Full);
			phylink_set(pl->supported, 50000baseLR_ER_FR_Full);
			phylink_set(pl->supported, 50000baseDR_Full);
			phylink_set(pl->supported, 100000baseKR4_Full);
			phylink_set(pl->supported, 100000baseSR4_Full);
			phylink_set(pl->supported, 100000baseCR4_Full);
			phylink_set(pl->supported, 100000baseLR4_ER4_Full);
			phylink_set(pl->supported, 100000baseKR2_Full);
			phylink_set(pl->supported, 100000baseSR2_Full);
			phylink_set(pl->supported, 100000baseCR2_Full);
			phylink_set(pl->supported, 100000baseLR2_ER2_FR2_Full);
			phylink_set(pl->supported, 100000baseDR2_Full);
			break;

		default:
			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)) {
			phylink_err(pl,
				    "failed to validate link configuration for in-band status\n");
			return -EINVAL;
		}

		/* Check if MAC/PCS also supports Autoneg. */
		pl->link_config.an_enabled = phylink_test(pl->supported, Autoneg);
	}

	return 0;
}

static void phylink_apply_manual_flow(struct phylink *pl,
				      struct phylink_link_state *state)
{
	/* If autoneg is disabled, pause AN is also disabled */
	if (!state->an_enabled)
		state->pause &= ~MLO_PAUSE_AN;

	/* Manual configuration of pause modes */
	if (!(pl->link_config.pause & MLO_PAUSE_AN))
		state->pause = pl->link_config.pause;
}

static void phylink_resolve_flow(struct phylink_link_state *state)
{
	bool tx_pause, rx_pause;

	state->pause = MLO_PAUSE_NONE;
	if (state->duplex == DUPLEX_FULL) {
		linkmode_resolve_pause(state->advertising,
				       state->lp_advertising,
				       &tx_pause, &rx_pause);
		if (tx_pause)
			state->pause |= MLO_PAUSE_TX;
		if (rx_pause)
			state->pause |= MLO_PAUSE_RX;
	}
}

static void phylink_mac_config(struct phylink *pl,
			       const struct phylink_link_state *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->cur_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->mac_ops->mac_config(pl->config, pl->cur_link_an_mode, state);
}

static void phylink_mac_pcs_an_restart(struct phylink *pl)
{
	if (pl->link_config.an_enabled &&
	    phy_interface_mode_is_8023z(pl->link_config.interface) &&
	    phylink_autoneg_inband(pl->cur_link_an_mode)) {
		if (pl->pcs_ops)
			pl->pcs_ops->pcs_an_restart(pl->pcs);
		else
			pl->mac_ops->mac_an_restart(pl->config);
	}
}

static void phylink_major_config(struct phylink *pl, bool restart,
				  const struct phylink_link_state *state)
{
	int err;

	phylink_dbg(pl, "major config %s\n", phy_modes(state->interface));

	if (pl->mac_ops->mac_prepare) {
		err = pl->mac_ops->mac_prepare(pl->config, pl->cur_link_an_mode,
					       state->interface);
		if (err < 0) {
			phylink_err(pl, "mac_prepare failed: %pe\n",
				    ERR_PTR(err));
			return;
		}
	}

	phylink_mac_config(pl, state);

	if (pl->pcs_ops) {
		err = pl->pcs_ops->pcs_config(pl->pcs, pl->cur_link_an_mode,
					      state->interface,
					      state->advertising,
					      !!(pl->link_config.pause &
						 MLO_PAUSE_AN));
		if (err < 0)
			phylink_err(pl, "pcs_config failed: %pe\n",
				    ERR_PTR(err));
		if (err > 0)
			restart = true;
	}
	if (restart)
		phylink_mac_pcs_an_restart(pl);

	if (pl->mac_ops->mac_finish) {
		err = pl->mac_ops->mac_finish(pl->config, pl->cur_link_an_mode,
					      state->interface);
		if (err < 0)
			phylink_err(pl, "mac_finish failed: %pe\n",
				    ERR_PTR(err));
	}
}

/*
 * Reconfigure for a change of inband advertisement.
 * If we have a separate PCS, we only need to call its pcs_config() method,
 * and then restart AN if it indicates something changed. Otherwise, we do
 * the full MAC reconfiguration.
 */
static int phylink_change_inband_advert(struct phylink *pl)
{
	int ret;

	if (test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state))
		return 0;

	if (!pl->pcs_ops) {
		/* Legacy method */
		phylink_mac_config(pl, &pl->link_config);
		phylink_mac_pcs_an_restart(pl);
		return 0;
	}

	phylink_dbg(pl, "%s: mode=%s/%s adv=%*pb pause=%02x\n", __func__,
		    phylink_an_mode_str(pl->cur_link_an_mode),
		    phy_modes(pl->link_config.interface),
		    __ETHTOOL_LINK_MODE_MASK_NBITS, pl->link_config.advertising,
		    pl->link_config.pause);

	/* Modern PCS-based method; update the advert at the PCS, and
	 * restart negotiation if the pcs_config() helper indicates that
	 * the programmed advertisement has changed.
	 */
	ret = pl->pcs_ops->pcs_config(pl->pcs, pl->cur_link_an_mode,
				      pl->link_config.interface,
				      pl->link_config.advertising,
				      !!(pl->link_config.pause & MLO_PAUSE_AN));
	if (ret < 0)
		return ret;

	if (ret > 0)
		phylink_mac_pcs_an_restart(pl);

	return 0;
}

static void phylink_mac_pcs_get_state(struct phylink *pl,
				      struct phylink_link_state *state)
{
	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;
	if  (state->an_enabled) {
		state->speed = SPEED_UNKNOWN;
		state->duplex = DUPLEX_UNKNOWN;
		state->pause = MLO_PAUSE_NONE;
	} else {
		state->speed =  pl->link_config.speed;
		state->duplex = pl->link_config.duplex;
		state->pause = pl->link_config.pause;
	}
	state->an_complete = 0;
	state->link = 1;

	if (pl->pcs_ops)
		pl->pcs_ops->pcs_get_state(pl->pcs, state);
	else if (pl->mac_ops->mac_pcs_get_state)
		pl->mac_ops->mac_pcs_get_state(pl->config, state);
	else
		state->link = 0;
}

/* The fixed state is... fixed except for the link state,
 * which may be determined by a GPIO or a callback.
 */
static void phylink_get_fixed_state(struct phylink *pl,
				    struct phylink_link_state *state)
{
	*state = pl->link_config;
	if (pl->config->get_fixed_state)
		pl->config->get_fixed_state(pl->config, state);
	else if (pl->link_gpio)
		state->link = !!gpiod_get_value_cansleep(pl->link_gpio);

	phylink_resolve_flow(state);
}

static void phylink_mac_initial_config(struct phylink *pl, bool force_restart)
{
	struct phylink_link_state link_state;

	switch (pl->cur_link_an_mode) {
	case MLO_AN_PHY:
		link_state = pl->phy_state;
		break;

	case MLO_AN_FIXED:
		phylink_get_fixed_state(pl, &link_state);
		break;

	case MLO_AN_INBAND:
		link_state = pl->link_config;
		if (link_state.interface == PHY_INTERFACE_MODE_SGMII)
			link_state.pause = MLO_PAUSE_NONE;
		break;

	default: /* can't happen */
		return;
	}

	link_state.link = false;

	phylink_apply_manual_flow(pl, &link_state);
	phylink_major_config(pl, force_restart, &link_state);
}

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_link_up(struct phylink *pl,
			    struct phylink_link_state link_state)
{
	struct net_device *ndev = pl->netdev;

	pl->cur_interface = link_state.interface;

	if (pl->pcs_ops && pl->pcs_ops->pcs_link_up)
		pl->pcs_ops->pcs_link_up(pl->pcs, pl->cur_link_an_mode,
					 pl->cur_interface,
					 link_state.speed, link_state.duplex);

	pl->mac_ops->mac_link_up(pl->config, pl->phydev,
				 pl->cur_link_an_mode, pl->cur_interface,
				 link_state.speed, link_state.duplex,
				 !!(link_state.pause & MLO_PAUSE_TX),
				 !!(link_state.pause & MLO_PAUSE_RX));

	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_link_down(struct phylink *pl)
{
	struct net_device *ndev = pl->netdev;

	if (ndev)
		netif_carrier_off(ndev);
	pl->mac_ops->mac_link_down(pl->config, pl->cur_link_an_mode,
				   pl->cur_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;
	bool mac_config = false;
	bool cur_link_state;

	mutex_lock(&pl->state_mutex);
	if (pl->netdev)
		cur_link_state = netif_carrier_ok(ndev);
	else
		cur_link_state = pl->old_link_state;

	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->cur_link_an_mode) {
		case MLO_AN_PHY:
			link_state = pl->phy_state;
			phylink_apply_manual_flow(pl, &link_state);
			mac_config = link_state.link;
			break;

		case MLO_AN_FIXED:
			phylink_get_fixed_state(pl, &link_state);
			mac_config = link_state.link;
			break;

		case MLO_AN_INBAND:
			phylink_mac_pcs_get_state(pl, &link_state);

			/* If we have a phy, the "up" state is the union of
			 * both the PHY and the MAC
			 */
			if (pl->phydev)
				link_state.link &= pl->phy_state.link;

			/* Only update if the PHY link is up */
			if (pl->phydev && pl->phy_state.link) {
				link_state.interface = pl->phy_state.interface;

				/* If we have a PHY, we need to update with
				 * the PHY flow control bits.
				 */
				link_state.pause = pl->phy_state.pause;
				mac_config = true;
			}
			phylink_apply_manual_flow(pl, &link_state);
			break;
		}
	}

	if (mac_config) {
		if (link_state.interface != pl->link_config.interface) {
			/* The interface has changed, force the link down and
			 * then reconfigure.
			 */
			if (cur_link_state) {
				phylink_link_down(pl);
				cur_link_state = false;
			}
			phylink_major_config(pl, false, &link_state);
			pl->link_config.interface = link_state.interface;
		} else if (!pl->pcs_ops) {
			/* The interface remains unchanged, only the speed,
			 * duplex or pause settings have changed. Call the
			 * old mac_config() method to configure the MAC/PCS
			 * only if we do not have a PCS installed (an
			 * unconverted user.)
			 */
			phylink_mac_config(pl, &link_state);
		}
	}

	if (link_state.link != cur_link_state) {
		pl->old_link_state = link_state.link;
		if (!link_state.link)
			phylink_link_down(pl);
		else
			phylink_link_up(pl, link_state);
	}
	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);
}

static void phylink_run_resolve_and_disable(struct phylink *pl, int bit)
{
	unsigned long state = pl->phylink_disable_state;

	set_bit(bit, &pl->phylink_disable_state);
	if (state == 0) {
		queue_work(system_power_efficient_wq, &pl->resolve);
		flush_work(&pl->resolve);
	}
}

static void phylink_fixed_poll(struct timer_list *t)
{
	struct phylink *pl = container_of(t, struct phylink, link_poll);

	mod_timer(t, jiffies + HZ);

	phylink_run_resolve(pl);
}

static const struct sfp_upstream_ops sfp_phylink_ops;

static int phylink_register_sfp(struct phylink *pl,
				struct fwnode_handle *fwnode)
{
	struct sfp_bus *bus;
	int ret;

	if (!fwnode)
		return 0;

	bus = sfp_bus_find_fwnode(fwnode);
	if (IS_ERR(bus)) {
		ret = PTR_ERR(bus);
		phylink_err(pl, "unable to attach SFP bus: %d\n", ret);
		return ret;
	}

	pl->sfp_bus = bus;

	ret = sfp_bus_add_upstream(bus, pl, &sfp_phylink_ops);
	sfp_bus_put(bus);

	return ret;
}

/**
 * phylink_create() - create a phylink instance
 * @config: a pointer to the target &struct phylink_config
 * @fwnode: a pointer to a &struct fwnode_handle describing the network
 *	interface
 * @iface: the desired link mode defined by &typedef phy_interface_t
 * @mac_ops: a pointer to a &struct phylink_mac_ops for the MAC.
 *
 * Create a new phylink instance, and parse the link parameters found in @np.
 * This will parse in-band modes, fixed-link or SFP configuration.
 *
 * Note: the rtnl lock must not be held when calling this function.
 *
 * 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 phylink_config *config,
			       struct fwnode_handle *fwnode,
			       phy_interface_t iface,
			       const struct phylink_mac_ops *mac_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->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)
		pl->link_port = PORT_BNC;
	else
		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->link_config.an_enabled = true;
	pl->mac_ops = mac_ops;
	__set_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
	timer_setup(&pl->link_poll, phylink_fixed_poll, 0);

	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, fwnode);
	if (ret < 0) {
		kfree(pl);
		return ERR_PTR(ret);
	}

	if (pl->cfg_link_an_mode == MLO_AN_FIXED) {
		ret = phylink_parse_fixedlink(pl, fwnode);
		if (ret < 0) {
			kfree(pl);
			return ERR_PTR(ret);
		}
	}

	pl->cur_link_an_mode = pl->cfg_link_an_mode;

	ret = phylink_register_sfp(pl, fwnode);
	if (ret < 0) {
		kfree(pl);
		return ERR_PTR(ret);
	}

	return pl;
}
EXPORT_SYMBOL_GPL(phylink_create);

/**
 * phylink_set_pcs() - set the current PCS for phylink to use
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @pcs: a pointer to the &struct phylink_pcs
 *
 * Bind the MAC PCS to phylink.  This may be called after phylink_create(),
 * in mac_prepare() or mac_config() methods if it is desired to dynamically
 * change the PCS.
 *
 * Please note that there are behavioural changes with the mac_config()
 * callback if a PCS is present (denoting a newer setup) so removing a PCS
 * is not supported, and if a PCS is going to be used, it must be registered
 * by calling phylink_set_pcs() at the latest in the first mac_config() call.
 */
void phylink_set_pcs(struct phylink *pl, struct phylink_pcs *pcs)
{
	pl->pcs = pcs;
	pl->pcs_ops = pcs->ops;
}
EXPORT_SYMBOL_GPL(phylink_set_pcs);

/**
 * phylink_destroy() - cleanup and destroy the phylink instance
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Destroy a phylink instance. Any PHY that has been attached must have been
 * cleaned up via phylink_disconnect_phy() prior to calling this function.
 *
 * Note: the rtnl lock must not be held when calling this function.
 */
void phylink_destroy(struct phylink *pl)
{
	sfp_bus_del_upstream(pl->sfp_bus);
	if (pl->link_gpio)
		gpiod_put(pl->link_gpio);

	cancel_work_sync(&pl->resolve);
	kfree(pl);
}
EXPORT_SYMBOL_GPL(phylink_destroy);

static void phylink_phy_change(struct phy_device *phydev, bool up)
{
	struct phylink *pl = phydev->phylink;
	bool tx_pause, rx_pause;

	phy_get_pause(phydev, &tx_pause, &rx_pause);

	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 (tx_pause)
		pl->phy_state.pause |= MLO_PAUSE_TX;
	if (rx_pause)
		pl->phy_state.pause |= MLO_PAUSE_RX;
	pl->phy_state.interface = phydev->interface;
	pl->phy_state.link = up;
	mutex_unlock(&pl->state_mutex);

	phylink_run_resolve(pl);

	phylink_dbg(pl, "phy link %s %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_pause_to_str(pl->phy_state.pause));
}

static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy,
			       phy_interface_t interface)
{
	struct phylink_link_state config;
	__ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
	char *irq_str;
	int ret;

	/*
	 * 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.
	 */
	phy_support_asym_pause(phy);

	memset(&config, 0, sizeof(config));
	linkmode_copy(supported, phy->supported);
	linkmode_copy(config.advertising, phy->advertising);

	/* Clause 45 PHYs switch their Serdes lane between several different
	 * modes, normally 10GBASE-R, SGMII. Some use 2500BASE-X for 2.5G
	 * speeds. We really need to know which interface modes the PHY and
	 * MAC supports to properly work out which linkmodes can be supported.
	 */
	if (phy->is_c45 &&
	    interface != PHY_INTERFACE_MODE_RXAUI &&
	    interface != PHY_INTERFACE_MODE_XAUI &&
	    interface != PHY_INTERFACE_MODE_USXGMII)
		config.interface = PHY_INTERFACE_MODE_NA;
	else
		config.interface = interface;

	ret = phylink_validate(pl, supported, &config);
	if (ret) {
		phylink_warn(pl, "validation of %s with support %*pb and advertisement %*pb failed: %d\n",
			     phy_modes(config.interface),
			     __ETHTOOL_LINK_MODE_MASK_NBITS, phy->supported,
			     __ETHTOOL_LINK_MODE_MASK_NBITS, config.advertising,
			     ret);
		return ret;
	}

	phy->phylink = pl;
	phy->phy_link_change = phylink_phy_change;

	irq_str = phy_attached_info_irq(phy);
	phylink_info(pl,
		     "PHY [%s] driver [%s] (irq=%s)\n",
		     dev_name(&phy->mdio.dev), phy->drv->name, irq_str);
	kfree(irq_str);

	mutex_lock(&phy->lock);
	mutex_lock(&pl->state_mutex);
	pl->phydev = phy;
	pl->phy_state.interface = interface;
	pl->phy_state.pause = MLO_PAUSE_NONE;
	pl->phy_state.speed = SPEED_UNKNOWN;
	pl->phy_state.duplex = DUPLEX_UNKNOWN;
	linkmode_copy(pl->supported, supported);
	linkmode_copy(pl->link_config.advertising, config.advertising);

	/* Restrict the phy advertisement according to the MAC support. */
	linkmode_copy(phy->advertising, config.advertising);
	mutex_unlock(&pl->state_mutex);
	mutex_unlock(&phy->lock);

	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);

	return 0;
}

static int phylink_attach_phy(struct phylink *pl, struct phy_device *phy,
			      phy_interface_t interface)
{
	if (WARN_ON(pl->cfg_link_an_mode == MLO_AN_FIXED ||
		    (pl->cfg_link_an_mode == MLO_AN_INBAND &&
		     phy_interface_mode_is_8023z(interface))))
		return -EINVAL;

	if (pl->phydev)
		return -EBUSY;

	return phy_attach_direct(pl->netdev, phy, 0, interface);
}

/**
 * phylink_connect_phy() - connect a PHY to the phylink instance
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @phy: a pointer to a &struct phy_device.
 *
 * Connect @phy to the phylink instance specified by @pl by calling
 * phy_attach_direct(). Configure the @phy according to the MAC driver's
 * capabilities, start the PHYLIB state machine and enable any interrupts
 * that the PHY supports.
 *
 * This updates the phylink's ethtool supported and advertising link mode
 * masks.
 *
 * Returns 0 on success or a negative errno.
 */
int phylink_connect_phy(struct phylink *pl, struct phy_device *phy)
{
	int ret;

	/* Use PHY device/driver interface */
	if (pl->link_interface == PHY_INTERFACE_MODE_NA) {
		pl->link_interface = phy->interface;
		pl->link_config.interface = pl->link_interface;
	}

	ret = phylink_attach_phy(pl, phy, pl->link_interface);
	if (ret < 0)
		return ret;

	ret = phylink_bringup_phy(pl, phy, pl->link_config.interface);
	if (ret)
		phy_detach(phy);

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_connect_phy);

/**
 * phylink_of_phy_connect() - connect the PHY specified in the DT mode.
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @dn: a pointer to a &struct device_node.
 * @flags: PHY-specific flags to communicate to the PHY device driver
 *
 * Connect the phy specified in the device node @dn to the phylink instance
 * specified by @pl. Actions specified in phylink_connect_phy() will be
 * performed.
 *
 * Returns 0 on success or a negative errno.
 */
int phylink_of_phy_connect(struct phylink *pl, struct device_node *dn,
			   u32 flags)
{
	return phylink_fwnode_phy_connect(pl, of_fwnode_handle(dn), flags);
}
EXPORT_SYMBOL_GPL(phylink_of_phy_connect);

/**
 * phylink_fwnode_phy_connect() - connect the PHY specified in the fwnode.
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @fwnode: a pointer to a &struct fwnode_handle.
 * @flags: PHY-specific flags to communicate to the PHY device driver
 *
 * Connect the phy specified @fwnode to the phylink instance specified
 * by @pl.
 *
 * Returns 0 on success or a negative errno.
 */
int phylink_fwnode_phy_connect(struct phylink *pl,
			       struct fwnode_handle *fwnode,
			       u32 flags)
{
	struct fwnode_handle *phy_fwnode;
	struct phy_device *phy_dev;
	int ret;

	/* Fixed links and 802.3z are handled without needing a PHY */
	if (pl->cfg_link_an_mode == MLO_AN_FIXED ||
	    (pl->cfg_link_an_mode == MLO_AN_INBAND &&
	     phy_interface_mode_is_8023z(pl->link_interface)))
		return 0;

	phy_fwnode = fwnode_get_phy_node(fwnode);
	if (IS_ERR(phy_fwnode)) {
		if (pl->cfg_link_an_mode == MLO_AN_PHY)
			return -ENODEV;
		return 0;
	}

	phy_dev = fwnode_phy_find_device(phy_fwnode);
	/* We're done with the phy_node handle */
	fwnode_handle_put(phy_fwnode);
	if (!phy_dev)
		return -ENODEV;

	ret = phy_attach_direct(pl->netdev, phy_dev, flags,
				pl->link_interface);
	if (ret) {
		phy_device_free(phy_dev);
		return ret;
	}

	ret = phylink_bringup_phy(pl, phy_dev, pl->link_config.interface);
	if (ret)
		phy_detach(phy_dev);

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_fwnode_phy_connect);

/**
 * phylink_disconnect_phy() - disconnect any PHY attached to the phylink
 *   instance.
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Disconnect any current PHY from the phylink instance described by @pl.
 */
void phylink_disconnect_phy(struct phylink *pl)
{
	struct phy_device *phy;

	ASSERT_RTNL();

	phy = pl->phydev;
	if (phy) {
		mutex_lock(&phy->lock);
		mutex_lock(&pl->state_mutex);
		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);

/**
 * phylink_mac_change() - notify phylink of a change in MAC state
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @up: indicates whether the link is currently up.
 *
 * The MAC driver should call this driver when the state of its link
 * changes (eg, link failure, new negotiation results, etc.)
 */
void phylink_mac_change(struct phylink *pl, bool up)
{
	if (!up)
		pl->mac_link_dropped = true;
	phylink_run_resolve(pl);
	phylink_dbg(pl, "mac link %s\n", up ? "up" : "down");
}
EXPORT_SYMBOL_GPL(phylink_mac_change);

static irqreturn_t phylink_link_handler(int irq, void *data)
{
	struct phylink *pl = data;

	phylink_run_resolve(pl);

	return IRQ_HANDLED;
}

/**
 * phylink_start() - start a phylink instance
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Start the phylink instance specified by @pl, configuring the MAC for the
 * desired link mode(s) and negotiation style. This should be called from the
 * network device driver's &struct net_device_ops ndo_open() method.
 */
void phylink_start(struct phylink *pl)
{
	bool poll = false;

	ASSERT_RTNL();

	phylink_info(pl, "configuring for %s/%s link mode\n",
		     phylink_an_mode_str(pl->cur_link_an_mode),
		     phy_modes(pl->link_config.interface));

	/* Always set the carrier off */
	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
	 * ensures that we set the appropriate advertisement for Serdes links.
	 *
	 * Restart autonegotiation if using 802.3z to ensure that the link
	 * parameters are properly negotiated.  This is necessary for DSA
	 * switches using 802.3z negotiation to ensure they see our modes.
	 */
	phylink_mac_initial_config(pl, true);

	clear_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
	phylink_run_resolve(pl);

	if (pl->cfg_link_an_mode == MLO_AN_FIXED && pl->link_gpio) {
		int irq = gpiod_to_irq(pl->link_gpio);

		if (irq > 0) {
			if (!request_irq(irq, phylink_link_handler,
					 IRQF_TRIGGER_RISING |
					 IRQF_TRIGGER_FALLING,
					 "netdev link", pl))
				pl->link_irq = irq;
			else
				irq = 0;
		}
		if (irq <= 0)
			poll = true;
	}

	switch (pl->cfg_link_an_mode) {
	case MLO_AN_FIXED:
		poll |= pl->config->poll_fixed_state;
		break;
	case MLO_AN_INBAND:
		poll |= pl->config->pcs_poll;
		if (pl->pcs)
			poll |= pl->pcs->poll;
		break;
	}
	if (poll)
		mod_timer(&pl->link_poll, jiffies + HZ);
	if (pl->phydev)
		phy_start(pl->phydev);
	if (pl->sfp_bus)
		sfp_upstream_start(pl->sfp_bus);
}
EXPORT_SYMBOL_GPL(phylink_start);

/**
 * phylink_stop() - stop a phylink instance
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Stop the phylink instance specified by @pl. This should be called from the
 * network device driver's &struct net_device_ops ndo_stop() method.  The
 * network device's carrier state should not be changed prior to calling this
 * function.
 *
 * This will synchronously bring down the link if the link is not already
 * down (in other words, it will trigger a mac_link_down() method call.)
 */
void phylink_stop(struct phylink *pl)
{
	ASSERT_RTNL();

	if (pl->sfp_bus)
		sfp_upstream_stop(pl->sfp_bus);
	if (pl->phydev)
		phy_stop(pl->phydev);
	del_timer_sync(&pl->link_poll);
	if (pl->link_irq) {
		free_irq(pl->link_irq, pl);
		pl->link_irq = 0;
	}

	phylink_run_resolve_and_disable(pl, PHYLINK_DISABLE_STOPPED);
}
EXPORT_SYMBOL_GPL(phylink_stop);

/**
 * phylink_suspend() - handle a network device suspend event
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @mac_wol: true if the MAC needs to receive packets for Wake-on-Lan
 *
 * Handle a network device suspend event. There are several cases:
 * - If Wake-on-Lan is not active, we can bring down the link between
 *   the MAC and PHY by calling phylink_stop().
 * - If Wake-on-Lan is active, and being handled only by the PHY, we
 *   can also bring down the link between the MAC and PHY.
 * - If Wake-on-Lan is active, but being handled by the MAC, the MAC
 *   still needs to receive packets, so we can not bring the link down.
 */
void phylink_suspend(struct phylink *pl, bool mac_wol)
{
	ASSERT_RTNL();

	if (mac_wol && (!pl->netdev || pl->netdev->wol_enabled)) {
		/* Wake-on-Lan enabled, MAC handling */
		mutex_lock(&pl->state_mutex);

		/* Stop the resolver bringing the link up */
		__set_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state);

		/* Disable the carrier, to prevent transmit timeouts,
		 * but one would hope all packets have been sent. This
		 * also means phylink_resolve() will do nothing.
		 */
		if (pl->netdev)
			netif_carrier_off(pl->netdev);
		else
			pl->old_link_state = false;

		/* We do not call mac_link_down() here as we want the
		 * link to remain up to receive the WoL packets.
		 */
		mutex_unlock(&pl->state_mutex);
	} else {
		phylink_stop(pl);
	}
}
EXPORT_SYMBOL_GPL(phylink_suspend);

/**
 * phylink_resume() - handle a network device resume event
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Undo the effects of phylink_suspend(), returning the link to an
 * operational state.
 */
void phylink_resume(struct phylink *pl)
{
	ASSERT_RTNL();

	if (test_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state)) {
		/* Wake-on-Lan enabled, MAC handling */

		/* Call mac_link_down() so we keep the overall state balanced.
		 * Do this under the state_mutex lock for consistency. This
		 * will cause a "Link Down" message to be printed during
		 * resume, which is harmless - the true link state will be
		 * printed when we run a resolve.
		 */
		mutex_lock(&pl->state_mutex);
		phylink_link_down(pl);
		mutex_unlock(&pl->state_mutex);

		/* Re-apply the link parameters so that all the settings get
		 * restored to the MAC.
		 */
		phylink_mac_initial_config(pl, true);

		/* Re-enable and re-resolve the link parameters */
		clear_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state);
		phylink_run_resolve(pl);
	} else {
		phylink_start(pl);
	}
}
EXPORT_SYMBOL_GPL(phylink_resume);

/**
 * phylink_ethtool_get_wol() - get the wake on lan parameters for the PHY
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @wol: a pointer to &struct ethtool_wolinfo to hold the read parameters
 *
 * Read the wake on lan parameters from the PHY attached to the phylink
 * instance specified by @pl. If no PHY is currently attached, report no
 * support for wake on lan.
 */
void phylink_ethtool_get_wol(struct phylink *pl, struct ethtool_wolinfo *wol)
{
	ASSERT_RTNL();

	wol->supported = 0;
	wol->wolopts = 0;

	if (pl->phydev)
		phy_ethtool_get_wol(pl->phydev, wol);
}
EXPORT_SYMBOL_GPL(phylink_ethtool_get_wol);

/**
 * phylink_ethtool_set_wol() - set wake on lan parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @wol: a pointer to &struct ethtool_wolinfo for the desired parameters
 *
 * Set the wake on lan parameters for the PHY attached to the phylink
 * instance specified by @pl. If no PHY is attached, returns %EOPNOTSUPP
 * error.
 *
 * Returns zero on success or negative errno code.
 */
int phylink_ethtool_set_wol(struct phylink *pl, struct ethtool_wolinfo *wol)
{
	int ret = -EOPNOTSUPP;

	ASSERT_RTNL();

	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;
}

/**
 * phylink_ethtool_ksettings_get() - get the current link settings
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @kset: a pointer to a &struct ethtool_link_ksettings to hold link settings
 *
 * Read the current link settings for the phylink instance specified by @pl.
 * This will be the link settings read from the MAC, PHY or fixed link
 * settings depending on the current negotiation mode.
 */
int phylink_ethtool_ksettings_get(struct phylink *pl,
				  struct ethtool_link_ksettings *kset)
{
	struct phylink_link_state link_state;

	ASSERT_RTNL();

	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->cur_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_INBAND:
		/* If there is a phy attached, then use the reported
		 * settings from the phy with no modification.
		 */
		if (pl->phydev)
			break;

		phylink_mac_pcs_get_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);

/**
 * phylink_ethtool_ksettings_set() - set the link settings
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @kset: a pointer to a &struct ethtool_link_ksettings for the desired modes
 */
int phylink_ethtool_ksettings_set(struct phylink *pl,
				  const struct ethtool_link_ksettings *kset)
{
	__ETHTOOL_DECLARE_LINK_MODE_MASK(support);
	struct phylink_link_state config;
	const struct phy_setting *s;

	ASSERT_RTNL();

	if (pl->phydev) {
		/* We can rely on phylib for this update; we also do not need
		 * to update the pl->link_config settings:
		 * - the configuration returned via ksettings_get() will come
		 *   from phylib whenever a PHY is present.
		 * - link_config.interface will be updated by the PHY calling
		 *   back via phylink_phy_change() and a subsequent resolve.
		 * - initial link configuration for PHY mode comes from the
		 *   last phy state updated via phylink_phy_change().
		 * - other configuration changes (e.g. pause modes) are
		 *   performed directly via phylib.
		 * - if in in-band mode with a PHY, the link configuration
		 *   is passed on the link from the PHY, and all of
		 *   link_config.{speed,duplex,an_enabled,pause} are not used.
		 * - the only possible use would be link_config.advertising
		 *   pause modes when in 1000base-X mode with a PHY, but in
		 *   the presence of a PHY, this should not be changed as that
		 *   should be determined from the media side advertisement.
		 */
		return phy_ethtool_ksettings_set(pl->phydev, kset);
	}

	config = pl->link_config;

	/* Mask out unsupported advertisements */
	linkmode_and(config.advertising, kset->link_modes.advertising,
		     pl->supported);

	/* FIXME: should we reject autoneg if phy/mac does not support it? */
	switch (kset->base.autoneg) {
	case AUTONEG_DISABLE:
		/* Autonegotiation disabled, select a suitable speed and
		 * duplex.
		 */
		s = phy_lookup_setting(kset->base.speed, kset->base.duplex,
				       pl->supported, false);
		if (!s)
			return -EINVAL;

		/* If we have a fixed link, refuse to change link parameters.
		 * If the link parameters match, accept them but do nothing.
		 */
		if (pl->cur_link_an_mode == MLO_AN_FIXED) {
			if (s->speed != pl->link_config.speed ||
			    s->duplex != pl->link_config.duplex)
				return -EINVAL;
			return 0;
		}

		config.speed = s->speed;
		config.duplex = s->duplex;
		break;

	case AUTONEG_ENABLE:
		/* If we have a fixed link, allow autonegotiation (since that
		 * is our default case) but do not allow the advertisement to
		 * be changed. If the advertisement matches, simply return.
		 */
		if (pl->cur_link_an_mode == MLO_AN_FIXED) {
			if (!linkmode_equal(config.advertising,
					    pl->link_config.advertising))
				return -EINVAL;
			return 0;
		}

		config.speed = SPEED_UNKNOWN;
		config.duplex = DUPLEX_UNKNOWN;
		break;

	default:
		return -EINVAL;
	}

	/* We have ruled out the case with a PHY attached, and the
	 * fixed-link cases.  All that is left are in-band links.
	 */
	config.an_enabled = kset->base.autoneg == AUTONEG_ENABLE;
	linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, config.advertising,
			 config.an_enabled);

	/* If this link is with an SFP, ensure that changes to advertised modes
	 * also cause the associated interface to be selected such that the
	 * link can be configured correctly.
	 */
	if (pl->sfp_bus) {
		config.interface = sfp_select_interface(pl->sfp_bus,
							config.advertising);
		if (config.interface == PHY_INTERFACE_MODE_NA) {
			phylink_err(pl,
				    "selection of interface failed, advertisement %*pb\n",
				    __ETHTOOL_LINK_MODE_MASK_NBITS,
				    config.advertising);
			return -EINVAL;
		}

		/* Revalidate with the selected interface */
		linkmode_copy(support, pl->supported);
		if (phylink_validate(pl, support, &config)) {
			phylink_err(pl, "validation of %s/%s with support %*pb failed\n",
				    phylink_an_mode_str(pl->cur_link_an_mode),
				    phy_modes(config.interface),
				    __ETHTOOL_LINK_MODE_MASK_NBITS, support);
			return -EINVAL;
		}
	} else {
		/* Validate without changing the current supported mask. */
		linkmode_copy(support, pl->supported);
		if (phylink_validate(pl, support, &config))
			return -EINVAL;
	}

	/* If autonegotiation is enabled, we must have an advertisement */
	if (config.an_enabled && phylink_is_empty_linkmode(config.advertising))
		return -EINVAL;

	mutex_lock(&pl->state_mutex);
	pl->link_config.speed = config.speed;
	pl->link_config.duplex = config.duplex;
	pl->link_config.an_enabled = config.an_enabled;

	if (pl->link_config.interface != config.interface) {
		/* The interface changed, e.g. 1000base-X <-> 2500base-X */
		/* We need to force the link down, then change the interface */
		if (pl->old_link_state) {
			phylink_link_down(pl);
			pl->old_link_state = false;
		}
		if (!test_bit(PHYLINK_DISABLE_STOPPED,
			      &pl->phylink_disable_state))
			phylink_major_config(pl, false, &config);
		pl->link_config.interface = config.interface;
		linkmode_copy(pl->link_config.advertising, config.advertising);
	} else if (!linkmode_equal(pl->link_config.advertising,
				   config.advertising)) {
		linkmode_copy(pl->link_config.advertising, config.advertising);
		phylink_change_inband_advert(pl);
	}
	mutex_unlock(&pl->state_mutex);

	return 0;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_ksettings_set);

/**
 * phylink_ethtool_nway_reset() - restart negotiation
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Restart negotiation for the phylink instance specified by @pl. This will
 * cause any attached phy to restart negotiation with the link partner, and
 * if the MAC is in a BaseX mode, the MAC will also be requested to restart
 * negotiation.
 *
 * Returns zero on success, or negative error code.
 */
int phylink_ethtool_nway_reset(struct phylink *pl)
{
	int ret = 0;

	ASSERT_RTNL();

	if (pl->phydev)
		ret = phy_restart_aneg(pl->phydev);
	phylink_mac_pcs_an_restart(pl);

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_nway_reset);

/**
 * phylink_ethtool_get_pauseparam() - get the current pause parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @pause: a pointer to a &struct ethtool_pauseparam
 */
void phylink_ethtool_get_pauseparam(struct phylink *pl,
				    struct ethtool_pauseparam *pause)
{
	ASSERT_RTNL();

	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);

/**
 * phylink_ethtool_set_pauseparam() - set the current pause parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @pause: a pointer to a &struct ethtool_pauseparam
 */
int phylink_ethtool_set_pauseparam(struct phylink *pl,
				   struct ethtool_pauseparam *pause)
{
	struct phylink_link_state *config = &pl->link_config;
	bool manual_changed;
	int pause_state;

	ASSERT_RTNL();

	if (pl->cur_link_an_mode == MLO_AN_FIXED)
		return -EOPNOTSUPP;

	if (!phylink_test(pl->supported, Pause) &&
	    !phylink_test(pl->supported, Asym_Pause))
		return -EOPNOTSUPP;

	if (!phylink_test(pl->supported, Asym_Pause) &&
	    pause->rx_pause != pause->tx_pause)
		return -EINVAL;

	pause_state = 0;
	if (pause->autoneg)
		pause_state |= MLO_PAUSE_AN;
	if (pause->rx_pause)
		pause_state |= MLO_PAUSE_RX;
	if (pause->tx_pause)
		pause_state |= MLO_PAUSE_TX;

	mutex_lock(&pl->state_mutex);
	/*
	 * See the comments for linkmode_set_pause(), wrt the deficiencies
	 * with the current implementation.  A solution to this issue would
	 * be:
	 * ethtool  Local device
	 *  rx  tx  Pause AsymDir
	 *  0   0   0     0
	 *  1   0   1     1
	 *  0   1   0     1
	 *  1   1   1     1
	 * and then use the ethtool rx/tx enablement status to mask the
	 * rx/tx pause resolution.
	 */
	linkmode_set_pause(config->advertising, pause->tx_pause,
			   pause->rx_pause);

	manual_changed = (config->pause ^ pause_state) & MLO_PAUSE_AN ||
			 (!(pause_state & MLO_PAUSE_AN) &&
			   (config->pause ^ pause_state) & MLO_PAUSE_TXRX_MASK);

	config->pause = pause_state;

	/* Update our in-band advertisement, triggering a renegotiation if
	 * the advertisement changed.
	 */
	if (!pl->phydev)
		phylink_change_inband_advert(pl);

	mutex_unlock(&pl->state_mutex);

	/* If we have a PHY, a change of the pause frame advertisement will
	 * cause phylib to renegotiate (if AN is enabled) which will in turn
	 * call our phylink_phy_change() and trigger a resolve.  Note that
	 * we can't hold our state mutex while calling phy_set_asym_pause().
	 */
	if (pl->phydev)
		phy_set_asym_pause(pl->phydev, pause->rx_pause,
				   pause->tx_pause);

	/* If the manual pause settings changed, make sure we trigger a
	 * resolve to update their state; we can not guarantee that the
	 * link will cycle.
	 */
	if (manual_changed) {
		pl->mac_link_dropped = true;
		phylink_run_resolve(pl);
	}

	return 0;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_set_pauseparam);

/**
 * phylink_get_eee_err() - read the energy efficient ethernet error
 *   counter
 * @pl: a pointer to a &struct phylink returned from phylink_create().
 *
 * Read the Energy Efficient Ethernet error counter from the PHY associated
 * with the phylink instance specified by @pl.
 *
 * Returns positive error counter value, or negative error code.
 */
int phylink_get_eee_err(struct phylink *pl)
{
	int ret = 0;

	ASSERT_RTNL();

	if (pl->phydev)
		ret = phy_get_eee_err(pl->phydev);

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_get_eee_err);

/**
 * phylink_init_eee() - init and check the EEE features
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @clk_stop_enable: allow PHY to stop receive clock
 *
 * Must be called either with RTNL held or within mac_link_up()
 */
int phylink_init_eee(struct phylink *pl, bool clk_stop_enable)
{
	int ret = -EOPNOTSUPP;

	if (pl->phydev)
		ret = phy_init_eee(pl->phydev, clk_stop_enable);

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_init_eee);

/**
 * phylink_ethtool_get_eee() - read the energy efficient ethernet parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @eee: a pointer to a &struct ethtool_eee for the read parameters
 */
int phylink_ethtool_get_eee(struct phylink *pl, struct ethtool_eee *eee)
{
	int ret = -EOPNOTSUPP;

	ASSERT_RTNL();

	if (pl->phydev)
		ret = phy_ethtool_get_eee(pl->phydev, eee);

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_get_eee);

/**
 * phylink_ethtool_set_eee() - set the energy efficient ethernet parameters
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @eee: a pointer to a &struct ethtool_eee for the desired parameters
 */
int phylink_ethtool_set_eee(struct phylink *pl, struct ethtool_eee *eee)
{
	int ret = -EOPNOTSUPP;

	ASSERT_RTNL();

	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(unsigned int reg,
				 struct phylink_link_state *state)
{
	struct fixed_phy_status fs;
	unsigned long *lpa = state->lp_advertising;
	int val;

	fs.link = state->link;
	fs.speed = state->speed;
	fs.duplex = state->duplex;
	fs.pause = test_bit(ETHTOOL_LINK_MODE_Pause_BIT, lpa);
	fs.asym_pause = test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, lpa);

	val = swphy_read_reg(reg, &fs);
	if (reg == MII_BMSR) {
		if (!state->an_complete)
			val &= ~BMSR_ANEGCOMPLETE;
	}
	return val;
}

static int phylink_phy_read(struct phylink *pl, unsigned int phy_id,
			    unsigned int reg)
{
	struct phy_device *phydev = pl->phydev;
	int prtad, devad;

	if (mdio_phy_id_is_c45(phy_id)) {
		prtad = mdio_phy_id_prtad(phy_id);
		devad = mdio_phy_id_devad(phy_id);
		devad = mdiobus_c45_addr(devad, reg);
	} else if (phydev->is_c45) {
		switch (reg) {
		case MII_BMCR:
		case MII_BMSR:
		case MII_PHYSID1:
		case MII_PHYSID2:
			devad = __ffs(phydev->c45_ids.mmds_present);
			break;
		case MII_ADVERTISE:
		case MII_LPA:
			if (!(phydev->c45_ids.mmds_present & MDIO_DEVS_AN))
				return -EINVAL;
			devad = MDIO_MMD_AN;
			if (reg == MII_ADVERTISE)
				reg = MDIO_AN_ADVERTISE;
			else
				reg = MDIO_AN_LPA;
			break;
		default:
			return -EINVAL;
		}
		prtad = phy_id;
		devad = mdiobus_c45_addr(devad, reg);
	} else {
		prtad = phy_id;
		devad = reg;
	}
	return mdiobus_read(pl->phydev->mdio.bus, prtad, devad);
}

static int phylink_phy_write(struct phylink *pl, unsigned int phy_id,
			     unsigned int reg, unsigned int val)
{
	struct phy_device *phydev = pl->phydev;
	int prtad, devad;

	if (mdio_phy_id_is_c45(phy_id)) {
		prtad = mdio_phy_id_prtad(phy_id);
		devad = mdio_phy_id_devad(phy_id);
		devad = mdiobus_c45_addr(devad, reg);
	} else if (phydev->is_c45) {
		switch (reg) {
		case MII_BMCR:
		case MII_BMSR:
		case MII_PHYSID1:
		case MII_PHYSID2:
			devad = __ffs(phydev->c45_ids.mmds_present);
			break;
		case MII_ADVERTISE:
		case MII_LPA:
			if (!(phydev->c45_ids.mmds_present & MDIO_DEVS_AN))
				return -EINVAL;
			devad = MDIO_MMD_AN;
			if (reg == MII_ADVERTISE)
				reg = MDIO_AN_ADVERTISE;
			else
				reg = MDIO_AN_LPA;
			break;
		default:
			return -EINVAL;
		}
		prtad = phy_id;
		devad = mdiobus_c45_addr(devad, reg);
	} else {
		prtad = phy_id;
		devad = reg;
	}

	return mdiobus_write(phydev->mdio.bus, prtad, devad, val);
}

static int phylink_mii_read(struct phylink *pl, unsigned int phy_id,
			    unsigned int reg)
{
	struct phylink_link_state state;
	int val = 0xffff;

	switch (pl->cur_link_an_mode) {
	case MLO_AN_FIXED:
		if (phy_id == 0) {
			phylink_get_fixed_state(pl, &state);
			val = phylink_mii_emul_read(reg, &state);
		}
		break;

	case MLO_AN_PHY:
		return -EOPNOTSUPP;

	case MLO_AN_INBAND:
		if (phy_id == 0) {
			phylink_mac_pcs_get_state(pl, &state);
			val = phylink_mii_emul_read(reg, &state);
		}
		break;
	}

	return val & 0xffff;
}

static int phylink_mii_write(struct phylink *pl, unsigned int phy_id,
			     unsigned int reg, unsigned int val)
{
	switch (pl->cur_link_an_mode) {
	case MLO_AN_FIXED:
		break;

	case MLO_AN_PHY:
		return -EOPNOTSUPP;

	case MLO_AN_INBAND:
		break;
	}

	return 0;
}

/**
 * phylink_mii_ioctl() - generic mii ioctl interface
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @ifr: a pointer to a &struct ifreq for socket ioctls
 * @cmd: ioctl cmd to execute
 *
 * Perform the specified MII ioctl on the PHY attached to the phylink instance
 * specified by @pl. If no PHY is attached, emulate the presence of the PHY.
 *
 * Returns: zero on success or negative error code.
 *
 * %SIOCGMIIPHY:
 *  read register from the current PHY.
 * %SIOCGMIIREG:
 *  read register from the specified PHY.
 * %SIOCSMIIREG:
 *  set a register on the specified PHY.
 */
int phylink_mii_ioctl(struct phylink *pl, struct ifreq *ifr, int cmd)
{
	struct mii_ioctl_data *mii = if_mii(ifr);
	int  ret;

	ASSERT_RTNL();

	if (pl->phydev) {
		/* PHYs only exist for MLO_AN_PHY and SGMII */
		switch (cmd) {
		case SIOCGMIIPHY:
			mii->phy_id = pl->phydev->mdio.addr;
			fallthrough;

		case SIOCGMIIREG:
			ret = phylink_phy_read(pl, mii->phy_id, mii->reg_num);
			if (ret >= 0) {
				mii->val_out = ret;
				ret = 0;
			}
			break;

		case SIOCSMIIREG:
			ret = phylink_phy_write(pl, mii->phy_id, mii->reg_num,
						mii->val_in);
			break;

		default:
			ret = phy_mii_ioctl(pl->phydev, ifr, cmd);
			break;
		}
	} else {
		switch (cmd) {
		case SIOCGMIIPHY:
			mii->phy_id = 0;
			fallthrough;

		case SIOCGMIIREG:
			ret = phylink_mii_read(pl, mii->phy_id, mii->reg_num);
			if (ret >= 0) {
				mii->val_out = ret;
				ret = 0;
			}
			break;

		case SIOCSMIIREG:
			ret = phylink_mii_write(pl, mii->phy_id, mii->reg_num,
						mii->val_in);
			break;

		default:
			ret = -EOPNOTSUPP;
			break;
		}
	}

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_mii_ioctl);

/**
 * phylink_speed_down() - set the non-SFP PHY to lowest speed supported by both
 *   link partners
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @sync: perform action synchronously
 *
 * If we have a PHY that is not part of a SFP module, then set the speed
 * as described in the phy_speed_down() function. Please see this function
 * for a description of the @sync parameter.
 *
 * Returns zero if there is no PHY, otherwise as per phy_speed_down().
 */
int phylink_speed_down(struct phylink *pl, bool sync)
{
	int ret = 0;

	ASSERT_RTNL();

	if (!pl->sfp_bus && pl->phydev)
		ret = phy_speed_down(pl->phydev, sync);

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_speed_down);

/**
 * phylink_speed_up() - restore the advertised speeds prior to the call to
 *   phylink_speed_down()
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * If we have a PHY that is not part of a SFP module, then restore the
 * PHY speeds as per phy_speed_up().
 *
 * Returns zero if there is no PHY, otherwise as per phy_speed_up().
 */
int phylink_speed_up(struct phylink *pl)
{
	int ret = 0;

	ASSERT_RTNL();

	if (!pl->sfp_bus && pl->phydev)
		ret = phy_speed_up(pl->phydev);

	return ret;
}
EXPORT_SYMBOL_GPL(phylink_speed_up);

static void phylink_sfp_attach(void *upstream, struct sfp_bus *bus)
{
	struct phylink *pl = upstream;

	pl->netdev->sfp_bus = bus;
}

static void phylink_sfp_detach(void *upstream, struct sfp_bus *bus)
{
	struct phylink *pl = upstream;

	pl->netdev->sfp_bus = NULL;
}

static int phylink_sfp_config(struct phylink *pl, u8 mode,
			      const unsigned long *supported,
			      const unsigned long *advertising)
{
	__ETHTOOL_DECLARE_LINK_MODE_MASK(support1);
	__ETHTOOL_DECLARE_LINK_MODE_MASK(support);
	struct phylink_link_state config;
	phy_interface_t iface;
	bool changed;
	int ret;

	linkmode_copy(support, supported);

	memset(&config, 0, sizeof(config));
	linkmode_copy(config.advertising, advertising);
	config.interface = PHY_INTERFACE_MODE_NA;
	config.speed = SPEED_UNKNOWN;
	config.duplex = DUPLEX_UNKNOWN;
	config.pause = MLO_PAUSE_AN;
	config.an_enabled = pl->link_config.an_enabled;

	/* Ignore errors if we're expecting a PHY to attach later */
	ret = phylink_validate(pl, support, &config);
	if (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, config.advertising);
	if (iface == PHY_INTERFACE_MODE_NA) {
		phylink_err(pl,
			    "selection of interface failed, advertisement %*pb\n",
			    __ETHTOOL_LINK_MODE_MASK_NBITS, config.advertising);
		return -EINVAL;
	}

	config.interface = iface;
	linkmode_copy(support1, support);
	ret = phylink_validate(pl, support1, &config);
	if (ret) {
		phylink_err(pl, "validation of %s/%s with support %*pb failed: %d\n",
			    phylink_an_mode_str(mode),
			    phy_modes(config.interface),
			    __ETHTOOL_LINK_MODE_MASK_NBITS, support, ret);
		return ret;
	}

	phylink_dbg(pl, "requesting link mode %s/%s with support %*pb\n",
		    phylink_an_mode_str(mode), phy_modes(config.interface),
		    __ETHTOOL_LINK_MODE_MASK_NBITS, support);

	if (phy_interface_mode_is_8023z(iface) && pl->phydev)
		return -EINVAL;

	changed = !linkmode_equal(pl->supported, support) ||
		  !linkmode_equal(pl->link_config.advertising,
				  config.advertising);
	if (changed) {
		linkmode_copy(pl->supported, support);
		linkmode_copy(pl->link_config.advertising, config.advertising);
	}

	if (pl->cur_link_an_mode != mode ||
	    pl->link_config.interface != config.interface) {
		pl->link_config.interface = config.interface;
		pl->cur_link_an_mode = mode;

		changed = true;

		phylink_info(pl, "switched to %s/%s link mode\n",
			     phylink_an_mode_str(mode),
			     phy_modes(config.interface));
	}

	pl->link_port = pl->sfp_port;

	if (changed && !test_bit(PHYLINK_DISABLE_STOPPED,
				 &pl->phylink_disable_state))
		phylink_mac_initial_config(pl, false);

	return ret;
}

static int phylink_sfp_module_insert(void *upstream,
				     const struct sfp_eeprom_id *id)
{
	struct phylink *pl = upstream;
	unsigned long *support = pl->sfp_support;

	ASSERT_RTNL();

	linkmode_zero(support);
	sfp_parse_support(pl->sfp_bus, id, support);
	pl->sfp_port = sfp_parse_port(pl->sfp_bus, id, support);

	/* If this module may have a PHY connecting later, defer until later */
	pl->sfp_may_have_phy = sfp_may_have_phy(pl->sfp_bus, id);
	if (pl->sfp_may_have_phy)
		return 0;

	return phylink_sfp_config(pl, MLO_AN_INBAND, support, support);
}

static int phylink_sfp_module_start(void *upstream)
{
	struct phylink *pl = upstream;

	/* If this SFP module has a PHY, start the PHY now. */
	if (pl->phydev) {
		phy_start(pl->phydev);
		return 0;
	}

	/* If the module may have a PHY but we didn't detect one we
	 * need to configure the MAC here.
	 */
	if (!pl->sfp_may_have_phy)
		return 0;

	return phylink_sfp_config(pl, MLO_AN_INBAND,
				  pl->sfp_support, pl->sfp_support);
}

static void phylink_sfp_module_stop(void *upstream)
{
	struct phylink *pl = upstream;

	/* If this SFP module has a PHY, stop it. */
	if (pl->phydev)
		phy_stop(pl->phydev);
}

static void phylink_sfp_link_down(void *upstream)
{
	struct phylink *pl = upstream;

	ASSERT_RTNL();

	phylink_run_resolve_and_disable(pl, PHYLINK_DISABLE_LINK);
}

static void phylink_sfp_link_up(void *upstream)
{
	struct phylink *pl = upstream;

	ASSERT_RTNL();

	clear_bit(PHYLINK_DISABLE_LINK, &pl->phylink_disable_state);
	phylink_run_resolve(pl);
}

/* The Broadcom BCM84881 in the Methode DM7052 is unable to provide a SGMII
 * or 802.3z control word, so inband will not work.
 */
static bool phylink_phy_no_inband(struct phy_device *phy)
{
	return phy->is_c45 &&
		(phy->c45_ids.device_ids[1] & 0xfffffff0) == 0xae025150;
}

static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
{
	struct phylink *pl = upstream;
	phy_interface_t interface;
	u8 mode;
	int ret;

	/*
	 * 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.
	 */
	phy_support_asym_pause(phy);

	if (phylink_phy_no_inband(phy))
		mode = MLO_AN_PHY;
	else
		mode = MLO_AN_INBAND;

	/* Do the initial configuration */
	ret = phylink_sfp_config(pl, mode, phy->supported, phy->advertising);
	if (ret < 0)
		return ret;

	interface = pl->link_config.interface;
	ret = phylink_attach_phy(pl, phy, interface);
	if (ret < 0)
		return ret;

	ret = phylink_bringup_phy(pl, phy, interface);
	if (ret)
		phy_detach(phy);

	return ret;
}

static void phylink_sfp_disconnect_phy(void *upstream)
{
	phylink_disconnect_phy(upstream);
}

static const struct sfp_upstream_ops sfp_phylink_ops = {
	.attach = phylink_sfp_attach,
	.detach = phylink_sfp_detach,
	.module_insert = phylink_sfp_module_insert,
	.module_start = phylink_sfp_module_start,
	.module_stop = phylink_sfp_module_stop,
	.link_up = phylink_sfp_link_up,
	.link_down = phylink_sfp_link_down,
	.connect_phy = phylink_sfp_connect_phy,
	.disconnect_phy = phylink_sfp_disconnect_phy,
};

/* Helpers for MAC drivers */

/**
 * phylink_helper_basex_speed() - 1000BaseX/2500BaseX helper
 * @state: a pointer to a &struct phylink_link_state
 *
 * Inspect the interface mode, advertising mask or forced speed and
 * decide whether to run at 2.5Gbit or 1Gbit appropriately, switching
 * the interface mode to suit.  @state->interface is appropriately
 * updated, and the advertising mask has the "other" baseX_Full flag
 * cleared.
 */
void phylink_helper_basex_speed(struct phylink_link_state *state)
{
	if (phy_interface_mode_is_8023z(state->interface)) {
		bool want_2500 = state->an_enabled ?
			phylink_test(state->advertising, 2500baseX_Full) :
			state->speed == SPEED_2500;

		if (want_2500) {
			phylink_clear(state->advertising, 1000baseX_Full);
			state->interface = PHY_INTERFACE_MODE_2500BASEX;
		} else {
			phylink_clear(state->advertising, 2500baseX_Full);
			state->interface = PHY_INTERFACE_MODE_1000BASEX;
		}
	}
}
EXPORT_SYMBOL_GPL(phylink_helper_basex_speed);

static void phylink_decode_c37_word(struct phylink_link_state *state,
				    uint16_t config_reg, int speed)
{
	bool tx_pause, rx_pause;
	int fd_bit;

	if (speed == SPEED_2500)
		fd_bit = ETHTOOL_LINK_MODE_2500baseX_Full_BIT;
	else
		fd_bit = ETHTOOL_LINK_MODE_1000baseX_Full_BIT;

	mii_lpa_mod_linkmode_x(state->lp_advertising, config_reg, fd_bit);

	if (linkmode_test_bit(fd_bit, state->advertising) &&
	    linkmode_test_bit(fd_bit, state->lp_advertising)) {
		state->speed = speed;
		state->duplex = DUPLEX_FULL;
	} else {
		/* negotiation failure */
		state->link = false;
	}

	linkmode_resolve_pause(state->advertising, state->lp_advertising,
			       &tx_pause, &rx_pause);

	if (tx_pause)
		state->pause |= MLO_PAUSE_TX;
	if (rx_pause)
		state->pause |= MLO_PAUSE_RX;
}

static void phylink_decode_sgmii_word(struct phylink_link_state *state,
				      uint16_t config_reg)
{
	if (!(config_reg & LPA_SGMII_LINK)) {
		state->link = false;
		return;
	}

	switch (config_reg & LPA_SGMII_SPD_MASK) {
	case LPA_SGMII_10:
		state->speed = SPEED_10;
		break;
	case LPA_SGMII_100:
		state->speed = SPEED_100;
		break;
	case LPA_SGMII_1000:
		state->speed = SPEED_1000;
		break;
	default:
		state->link = false;
		return;
	}
	if (config_reg & LPA_SGMII_FULL_DUPLEX)
		state->duplex = DUPLEX_FULL;
	else
		state->duplex = DUPLEX_HALF;
}

/**
 * phylink_decode_usxgmii_word() - decode the USXGMII word from a MAC PCS
 * @state: a pointer to a struct phylink_link_state.
 * @lpa: a 16 bit value which stores the USXGMII auto-negotiation word
 *
 * Helper for MAC PCS supporting the USXGMII protocol and the auto-negotiation
 * code word.  Decode the USXGMII code word and populate the corresponding fields
 * (speed, duplex) into the phylink_link_state structure.
 */
void phylink_decode_usxgmii_word(struct phylink_link_state *state,
				 uint16_t lpa)
{
	switch (lpa & MDIO_USXGMII_SPD_MASK) {
	case MDIO_USXGMII_10:
		state->speed = SPEED_10;
		break;
	case MDIO_USXGMII_100:
		state->speed = SPEED_100;
		break;
	case MDIO_USXGMII_1000:
		state->speed = SPEED_1000;
		break;
	case MDIO_USXGMII_2500:
		state->speed = SPEED_2500;
		break;
	case MDIO_USXGMII_5000:
		state->speed = SPEED_5000;
		break;
	case MDIO_USXGMII_10G:
		state->speed = SPEED_10000;
		break;
	default:
		state->link = false;
		return;
	}

	if (lpa & MDIO_USXGMII_FULL_DUPLEX)
		state->duplex = DUPLEX_FULL;
	else
		state->duplex = DUPLEX_HALF;
}
EXPORT_SYMBOL_GPL(phylink_decode_usxgmii_word);

/**
 * phylink_mii_c22_pcs_get_state() - read the MAC PCS state
 * @pcs: a pointer to a &struct mdio_device.
 * @state: a pointer to a &struct phylink_link_state.
 *
 * Helper for MAC PCS supporting the 802.3 clause 22 register set for
 * clause 37 negotiation and/or SGMII control.
 *
 * Read the MAC PCS state from the MII device configured in @config and
 * parse the Clause 37 or Cisco SGMII link partner negotiation word into
 * the phylink @state structure. This is suitable to be directly plugged
 * into the mac_pcs_get_state() member of the struct phylink_mac_ops
 * structure.
 */
void phylink_mii_c22_pcs_get_state(struct mdio_device *pcs,
				   struct phylink_link_state *state)
{
	int bmsr, lpa;

	bmsr = mdiodev_read(pcs, MII_BMSR);
	lpa = mdiodev_read(pcs, MII_LPA);
	if (bmsr < 0 || lpa < 0) {
		state->link = false;
		return;
	}

	state->link = !!(bmsr & BMSR_LSTATUS);
	state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
	/* If there is no link or autonegotiation is disabled, the LP advertisement
	 * data is not meaningful, so don't go any further.
	 */
	if (!state->link || !state->an_enabled)
		return;

	switch (state->interface) {
	case PHY_INTERFACE_MODE_1000BASEX:
		phylink_decode_c37_word(state, lpa, SPEED_1000);
		break;

	case PHY_INTERFACE_MODE_2500BASEX:
		phylink_decode_c37_word(state, lpa, SPEED_2500);
		break;

	case PHY_INTERFACE_MODE_SGMII:
	case PHY_INTERFACE_MODE_QSGMII:
		phylink_decode_sgmii_word(state, lpa);
		break;

	default:
		state->link = false;
		break;
	}
}
EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_get_state);

/**
 * phylink_mii_c22_pcs_set_advertisement() - configure the clause 37 PCS
 *	advertisement
 * @pcs: a pointer to a &struct mdio_device.
 * @interface: the PHY interface mode being configured
 * @advertising: the ethtool advertisement mask
 *
 * Helper for MAC PCS supporting the 802.3 clause 22 register set for
 * clause 37 negotiation and/or SGMII control.
 *
 * Configure the clause 37 PCS advertisement as specified by @state. This
 * does not trigger a renegotiation; phylink will do that via the
 * mac_an_restart() method of the struct phylink_mac_ops structure.
 *
 * Returns negative error code on failure to configure the advertisement,
 * zero if no change has been made, or one if the advertisement has changed.
 */
int phylink_mii_c22_pcs_set_advertisement(struct mdio_device *pcs,
					  phy_interface_t interface,
					  const unsigned long *advertising)
{
	u16 adv;

	switch (interface) {
	case PHY_INTERFACE_MODE_1000BASEX:
	case PHY_INTERFACE_MODE_2500BASEX:
		adv = ADVERTISE_1000XFULL;
		if (linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
				      advertising))
			adv |= ADVERTISE_1000XPAUSE;
		if (linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
				      advertising))
			adv |= ADVERTISE_1000XPSE_ASYM;

		return mdiodev_modify_changed(pcs, MII_ADVERTISE, 0xffff, adv);

	case PHY_INTERFACE_MODE_SGMII:
		return mdiodev_modify_changed(pcs, MII_ADVERTISE, 0xffff, 0x0001);

	default:
		/* Nothing to do for other modes */
		return 0;
	}
}
EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_set_advertisement);

/**
 * phylink_mii_c22_pcs_config() - configure clause 22 PCS
 * @pcs: a pointer to a &struct mdio_device.
 * @mode: link autonegotiation mode
 * @interface: the PHY interface mode being configured
 * @advertising: the ethtool advertisement mask
 *
 * Configure a Clause 22 PCS PHY with the appropriate negotiation
 * parameters for the @mode, @interface and @advertising parameters.
 * Returns negative error number on failure, zero if the advertisement
 * has not changed, or positive if there is a change.
 */
int phylink_mii_c22_pcs_config(struct mdio_device *pcs, unsigned int mode,
			       phy_interface_t interface,
			       const unsigned long *advertising)
{
	bool changed;
	u16 bmcr;
	int ret;

	ret = phylink_mii_c22_pcs_set_advertisement(pcs, interface,
						    advertising);
	if (ret < 0)
		return ret;

	changed = ret > 0;

	/* Ensure ISOLATE bit is disabled */
	if (mode == MLO_AN_INBAND &&
	    linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, advertising))
		bmcr = BMCR_ANENABLE;
	else
		bmcr = 0;

	ret = mdiodev_modify(pcs, MII_BMCR, BMCR_ANENABLE | BMCR_ISOLATE, bmcr);
	if (ret < 0)
		return ret;

	return changed ? 1 : 0;
}
EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_config);

/**
 * phylink_mii_c22_pcs_an_restart() - restart 802.3z autonegotiation
 * @pcs: a pointer to a &struct mdio_device.
 *
 * Helper for MAC PCS supporting the 802.3 clause 22 register set for
 * clause 37 negotiation.
 *
 * Restart the clause 37 negotiation with the link partner. This is
 * suitable to be directly plugged into the mac_pcs_get_state() member
 * of the struct phylink_mac_ops structure.
 */
void phylink_mii_c22_pcs_an_restart(struct mdio_device *pcs)
{
	int val = mdiodev_read(pcs, MII_BMCR);

	if (val >= 0) {
		val |= BMCR_ANRESTART;

		mdiodev_write(pcs, MII_BMCR, val);
	}
}
EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_an_restart);

void phylink_mii_c45_pcs_get_state(struct mdio_device *pcs,
				   struct phylink_link_state *state)
{
	struct mii_bus *bus = pcs->bus;
	int addr = pcs->addr;
	int stat;

	stat = mdiobus_c45_read(bus, addr, MDIO_MMD_PCS, MDIO_STAT1);
	if (stat < 0) {
		state->link = false;
		return;
	}

	state->link = !!(stat & MDIO_STAT1_LSTATUS);
	if (!state->link)
		return;

	switch (state->interface) {
	case PHY_INTERFACE_MODE_10GBASER:
		state->speed = SPEED_10000;
		state->duplex = DUPLEX_FULL;
		break;

	default:
		break;
	}
}
EXPORT_SYMBOL_GPL(phylink_mii_c45_pcs_get_state);

MODULE_LICENSE("GPL v2");