// 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 "phy-caps.h"
#include "sfp.h"
#include "swphy.h"

enum {
        PHYLINK_DISABLE_STOPPED,
        PHYLINK_DISABLE_LINK,
        PHYLINK_DISABLE_MAC_WOL,
        PHYLINK_DISABLE_REPLAY,

        PCS_STATE_DOWN = 0,
        PCS_STATE_STARTING,
        PCS_STATE_STARTED,
};

/**
 * struct phylink - internal data type for phylink
 */
struct phylink {
        /* private: */
        struct net_device *netdev;
        const struct phylink_mac_ops *mac_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 req_link_an_mode;            /* Requested MLO_AN_xxx mode */
        u8 act_link_an_mode;            /* Active MLO_AN_xxx mode */
        u8 link_port;                   /* The current non-phy ethtool port */
        __ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
        __ETHTOOL_DECLARE_LINK_MODE_MASK(supported_lpi);

        /* 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;

        struct mutex state_mutex;
        /* Serialize updates to pl->phydev with phylink_resolve() */
        struct mutex phydev_mutex;
        struct phylink_link_state phy_state;
        unsigned int phy_ib_mode;
        struct work_struct resolve;
        unsigned int pcs_neg_mode;
        unsigned int pcs_state;

        bool link_failed;
        bool suspend_link_up;
        bool force_major_config;
        bool major_config_failed;
        bool mac_supports_eee_ops;
        bool mac_supports_eee;
        bool phy_enable_tx_lpi;
        bool mac_enable_tx_lpi;
        bool mac_tx_clk_stop;
        u32 mac_tx_lpi_timer;
        u8 mac_rx_clk_stop_blocked;

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

        struct eee_config eee_cfg;

        u32 wolopts_mac;
        u8 wol_sopass[SOPASS_MAX];
};

#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

static const phy_interface_t phylink_sfp_interface_preference[] = {
        PHY_INTERFACE_MODE_100GBASEP,
        PHY_INTERFACE_MODE_50GBASER,
        PHY_INTERFACE_MODE_LAUI,
        PHY_INTERFACE_MODE_25GBASER,
        PHY_INTERFACE_MODE_USXGMII,
        PHY_INTERFACE_MODE_10GBASER,
        PHY_INTERFACE_MODE_5GBASER,
        PHY_INTERFACE_MODE_2500BASEX,
        PHY_INTERFACE_MODE_SGMII,
        PHY_INTERFACE_MODE_1000BASEX,
        PHY_INTERFACE_MODE_100BASEX,
};

static DECLARE_PHY_INTERFACE_MASK(phylink_sfp_interfaces);

/**
 * 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);

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 const char *phylink_pcs_mode_str(unsigned int mode)
{
        if (!mode)
                return "none";

        if (mode & PHYLINK_PCS_NEG_OUTBAND)
                return "outband";

        if (mode & PHYLINK_PCS_NEG_INBAND) {
                if (mode & PHYLINK_PCS_NEG_ENABLED)
                        return "inband,an-enabled";
                else
                        return "inband,an-disabled";
        }

        return "unknown";
}

static unsigned int phylink_interface_signal_rate(phy_interface_t interface)
{
        switch (interface) {
        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_1000BASEX: /* 1.25Mbd */
                return 1250;
        case PHY_INTERFACE_MODE_2500BASEX: /* 3.125Mbd */
                return 3125;
        case PHY_INTERFACE_MODE_5GBASER: /* 5.15625Mbd */
                return 5156;
        case PHY_INTERFACE_MODE_10GBASER: /* 10.3125Mbd */
                return 10313;
        default:
                return 0;
        }
}

/**
 * phylink_interface_max_speed() - get the maximum speed of a phy interface
 * @interface: phy interface mode defined by &typedef phy_interface_t
 *
 * Determine the maximum speed of a phy interface. This is intended to help
 * determine the correct speed to pass to the MAC when the phy is performing
 * rate matching.
 *
 * Return: The maximum speed of @interface
 */
static int phylink_interface_max_speed(phy_interface_t interface)
{
        switch (interface) {
        case PHY_INTERFACE_MODE_100BASEX:
        case PHY_INTERFACE_MODE_REVRMII:
        case PHY_INTERFACE_MODE_RMII:
        case PHY_INTERFACE_MODE_SMII:
        case PHY_INTERFACE_MODE_REVMII:
        case PHY_INTERFACE_MODE_MII:
        case PHY_INTERFACE_MODE_MIILITE:
                return SPEED_100;

        case PHY_INTERFACE_MODE_TBI:
        case PHY_INTERFACE_MODE_MOCA:
        case PHY_INTERFACE_MODE_RTBI:
        case PHY_INTERFACE_MODE_1000BASEX:
        case PHY_INTERFACE_MODE_1000BASEKX:
        case PHY_INTERFACE_MODE_TRGMII:
        case PHY_INTERFACE_MODE_RGMII_TXID:
        case PHY_INTERFACE_MODE_RGMII_RXID:
        case PHY_INTERFACE_MODE_RGMII_ID:
        case PHY_INTERFACE_MODE_RGMII:
        case PHY_INTERFACE_MODE_PSGMII:
        case PHY_INTERFACE_MODE_QSGMII:
        case PHY_INTERFACE_MODE_QUSGMII:
        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_GMII:
                return SPEED_1000;

        case PHY_INTERFACE_MODE_2500BASEX:
        case PHY_INTERFACE_MODE_10G_QXGMII:
                return SPEED_2500;

        case PHY_INTERFACE_MODE_5GBASER:
                return SPEED_5000;

        case PHY_INTERFACE_MODE_XGMII:
        case PHY_INTERFACE_MODE_RXAUI:
        case PHY_INTERFACE_MODE_XAUI:
        case PHY_INTERFACE_MODE_10GBASER:
        case PHY_INTERFACE_MODE_10GKR:
        case PHY_INTERFACE_MODE_USXGMII:
                return SPEED_10000;

        case PHY_INTERFACE_MODE_25GBASER:
                return SPEED_25000;

        case PHY_INTERFACE_MODE_XLGMII:
                return SPEED_40000;

        case PHY_INTERFACE_MODE_50GBASER:
        case PHY_INTERFACE_MODE_LAUI:
                return SPEED_50000;

        case PHY_INTERFACE_MODE_100GBASEP:
                return SPEED_100000;

        case PHY_INTERFACE_MODE_INTERNAL:
        case PHY_INTERFACE_MODE_NA:
        case PHY_INTERFACE_MODE_MAX:
                /* No idea! Garbage in, unknown out */
                return SPEED_UNKNOWN;
        }

        /* If we get here, someone forgot to add an interface mode above */
        WARN_ON_ONCE(1);
        return SPEED_UNKNOWN;
}

static struct {
        unsigned long mask;
        int speed;
        unsigned int duplex;
        unsigned int caps_bit;
} phylink_caps_params[] = {
        { MAC_400000FD, SPEED_400000, DUPLEX_FULL, BIT(LINK_CAPA_400000FD) },
        { MAC_200000FD, SPEED_200000, DUPLEX_FULL, BIT(LINK_CAPA_200000FD) },
        { MAC_100000FD, SPEED_100000, DUPLEX_FULL, BIT(LINK_CAPA_100000FD) },
        { MAC_80000FD,  SPEED_80000,  DUPLEX_FULL, BIT(LINK_CAPA_80000FD) },
        { MAC_56000FD,  SPEED_56000,  DUPLEX_FULL, BIT(LINK_CAPA_56000FD) },
        { MAC_50000FD,  SPEED_50000,  DUPLEX_FULL, BIT(LINK_CAPA_50000FD) },
        { MAC_40000FD,  SPEED_40000,  DUPLEX_FULL, BIT(LINK_CAPA_40000FD) },
        { MAC_25000FD,  SPEED_25000,  DUPLEX_FULL, BIT(LINK_CAPA_25000FD) },
        { MAC_20000FD,  SPEED_20000,  DUPLEX_FULL, BIT(LINK_CAPA_20000FD) },
        { MAC_10000FD,  SPEED_10000,  DUPLEX_FULL, BIT(LINK_CAPA_10000FD) },
        { MAC_5000FD,   SPEED_5000,   DUPLEX_FULL, BIT(LINK_CAPA_5000FD) },
        { MAC_2500FD,   SPEED_2500,   DUPLEX_FULL, BIT(LINK_CAPA_2500FD) },
        { MAC_1000FD,   SPEED_1000,   DUPLEX_FULL, BIT(LINK_CAPA_1000FD) },
        { MAC_1000HD,   SPEED_1000,   DUPLEX_HALF, BIT(LINK_CAPA_1000HD) },
        { MAC_100FD,    SPEED_100,    DUPLEX_FULL, BIT(LINK_CAPA_100FD) },
        { MAC_100HD,    SPEED_100,    DUPLEX_HALF, BIT(LINK_CAPA_100HD) },
        { MAC_10FD,     SPEED_10,     DUPLEX_FULL, BIT(LINK_CAPA_10FD) },
        { MAC_10HD,     SPEED_10,     DUPLEX_HALF, BIT(LINK_CAPA_10HD) },
};

/**
 * phylink_caps_to_link_caps() - Convert a set of MAC capabilities LINK caps
 * @caps: A set of MAC capabilities
 *
 * Returns: The corresponding set of LINK_CAPA as defined in phy-caps.h
 */
static unsigned long phylink_caps_to_link_caps(unsigned long caps)
{
        unsigned long link_caps = 0;
        int i;

        for (i = 0; i <  ARRAY_SIZE(phylink_caps_params); i++)
                if (caps & phylink_caps_params[i].mask)
                        link_caps |= phylink_caps_params[i].caps_bit;

        return link_caps;
}

static unsigned long phylink_link_caps_to_mac_caps(unsigned long link_caps)
{
        unsigned long caps = 0;
        int i;

        for (i = 0; i <  ARRAY_SIZE(phylink_caps_params); i++)
                if (link_caps & phylink_caps_params[i].caps_bit)
                        caps |= phylink_caps_params[i].mask;

        return caps;
}

/**
 * phylink_caps_to_linkmodes() - Convert capabilities to ethtool link modes
 * @linkmodes: ethtool linkmode mask (must be already initialised)
 * @caps: bitmask of MAC capabilities
 *
 * Set all possible pause, speed and duplex linkmodes in @linkmodes that are
 * supported by the @caps. @linkmodes must have been initialised previously.
 */
static void phylink_caps_to_linkmodes(unsigned long *linkmodes,
                                      unsigned long caps)
{
        unsigned long link_caps = phylink_caps_to_link_caps(caps);

        if (caps & MAC_SYM_PAUSE)
                __set_bit(ETHTOOL_LINK_MODE_Pause_BIT, linkmodes);

        if (caps & MAC_ASYM_PAUSE)
                __set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, linkmodes);

        phy_caps_linkmodes(link_caps, linkmodes);
}

/**
 * phylink_limit_mac_speed - limit the phylink_config to a maximum speed
 * @config: pointer to a &struct phylink_config
 * @max_speed: maximum speed
 *
 * Mask off MAC capabilities for speeds higher than the @max_speed parameter.
 * Any further motifications of config.mac_capabilities will override this.
 */
void phylink_limit_mac_speed(struct phylink_config *config, u32 max_speed)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(phylink_caps_params) &&
                    phylink_caps_params[i].speed > max_speed; i++)
                config->mac_capabilities &= ~phylink_caps_params[i].mask;
}
EXPORT_SYMBOL_GPL(phylink_limit_mac_speed);

/**
 * phylink_cap_from_speed_duplex - Get mac capability from speed/duplex
 * @speed: the speed to search for
 * @duplex: the duplex to search for
 *
 * Find the mac capability for a given speed and duplex.
 *
 * Return: A mask with the mac capability patching @speed and @duplex, or 0 if
 *         there were no matches.
 */
static unsigned long phylink_cap_from_speed_duplex(int speed,
                                                   unsigned int duplex)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(phylink_caps_params); i++) {
                if (speed == phylink_caps_params[i].speed &&
                    duplex == phylink_caps_params[i].duplex)
                        return phylink_caps_params[i].mask;
        }

        return 0;
}

/**
 * phylink_get_capabilities() - get capabilities for a given MAC
 * @interface: phy interface mode defined by &typedef phy_interface_t
 * @mac_capabilities: bitmask of MAC capabilities
 * @rate_matching: type of rate matching being performed
 *
 * Get the MAC capabilities that are supported by the @interface mode and
 * @mac_capabilities.
 */
static unsigned long phylink_get_capabilities(phy_interface_t interface,
                                              unsigned long mac_capabilities,
                                              int rate_matching)
{
        unsigned long link_caps = phy_caps_from_interface(interface);
        int max_speed = phylink_interface_max_speed(interface);
        unsigned long caps = MAC_SYM_PAUSE | MAC_ASYM_PAUSE;
        unsigned long matched_caps = 0;

        caps |= phylink_link_caps_to_mac_caps(link_caps);

        switch (rate_matching) {
        case RATE_MATCH_OPEN_LOOP:
                /* TODO */
                fallthrough;
        case RATE_MATCH_NONE:
                matched_caps = 0;
                break;
        case RATE_MATCH_PAUSE: {
                /* The MAC must support asymmetric pause towards the local
                 * device for this. We could allow just symmetric pause, but
                 * then we might have to renegotiate if the link partner
                 * doesn't support pause. This is because there's no way to
                 * accept pause frames without transmitting them if we only
                 * support symmetric pause.
                 */
                if (!(mac_capabilities & MAC_SYM_PAUSE) ||
                    !(mac_capabilities & MAC_ASYM_PAUSE))
                        break;

                /* We can't adapt if the MAC doesn't support the interface's
                 * max speed at full duplex.
                 */
                if (mac_capabilities &
                    phylink_cap_from_speed_duplex(max_speed, DUPLEX_FULL))
                        matched_caps = GENMASK(__fls(caps), __fls(MAC_10HD));
                break;
        }
        case RATE_MATCH_CRS:
                /* The MAC must support half duplex at the interface's max
                 * speed.
                 */
                if (mac_capabilities &
                    phylink_cap_from_speed_duplex(max_speed, DUPLEX_HALF)) {
                        matched_caps = GENMASK(__fls(caps), __fls(MAC_10HD));
                        matched_caps &= mac_capabilities;
                }
                break;
        }

        return (caps & mac_capabilities) | matched_caps;
}

/**
 * phylink_validate_mask_caps() - Restrict link modes based on caps
 * @supported: ethtool bitmask for supported link modes.
 * @state: pointer to a &struct phylink_link_state.
 * @mac_capabilities: bitmask of MAC capabilities
 *
 * Calculate the supported link modes based on @mac_capabilities, and restrict
 * @supported and @state based on that. Use this function if your capabiliies
 * aren't constant, such as if they vary depending on the interface.
 */
static void phylink_validate_mask_caps(unsigned long *supported,
                                       struct phylink_link_state *state,
                                       unsigned long mac_capabilities)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
        unsigned long caps;

        phylink_set_port_modes(mask);
        phylink_set(mask, Autoneg);
        caps = phylink_get_capabilities(state->interface, mac_capabilities,
                                        state->rate_matching);
        phylink_caps_to_linkmodes(mask, caps);

        linkmode_and(supported, supported, mask);
        linkmode_and(state->advertising, state->advertising, mask);
}

static int phylink_validate_mac_and_pcs(struct phylink *pl,
                                        unsigned long *supported,
                                        struct phylink_link_state *state)
{
        struct phylink_pcs *pcs = NULL;
        unsigned long capabilities;
        int ret;

        /* Get the PCS for this interface mode */
        if (pl->mac_ops->mac_select_pcs) {
                pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
                if (IS_ERR(pcs))
                        return PTR_ERR(pcs);
        }

        if (pcs) {
                /* The PCS, if present, must be setup before phylink_create()
                 * has been called. If the ops is not initialised, print an
                 * error and backtrace rather than oopsing the kernel.
                 */
                if (!pcs->ops) {
                        phylink_err(pl, "interface %s: uninitialised PCS\n",
                                    phy_modes(state->interface));
                        dump_stack();
                        return -EINVAL;
                }

                /* Ensure that this PCS supports the interface which the MAC
                 * returned it for. It is an error for the MAC to return a PCS
                 * that does not support the interface mode.
                 */
                if (!phy_interface_empty(pcs->supported_interfaces) &&
                    !test_bit(state->interface, pcs->supported_interfaces)) {
                        phylink_err(pl, "MAC returned PCS which does not support %s\n",
                                    phy_modes(state->interface));
                        return -EINVAL;
                }

                /* Validate the link parameters with the PCS */
                if (pcs->ops->pcs_validate) {
                        ret = pcs->ops->pcs_validate(pcs, supported, state);
                        if (ret < 0 || phylink_is_empty_linkmode(supported))
                                return -EINVAL;

                        /* Ensure the advertising mask is a subset of the
                         * supported mask.
                         */
                        linkmode_and(state->advertising, state->advertising,
                                     supported);
                }
        }

        /* Then validate the link parameters with the MAC */
        if (pl->mac_ops->mac_get_caps)
                capabilities = pl->mac_ops->mac_get_caps(pl->config,
                                                         state->interface);
        else
                capabilities = pl->config->mac_capabilities;

        phylink_validate_mask_caps(supported, state, capabilities);

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

static void phylink_validate_one(struct phylink *pl, struct phy_device *phy,
                                 const unsigned long *supported,
                                 const struct phylink_link_state *state,
                                 phy_interface_t interface,
                                 unsigned long *accum_supported,
                                 unsigned long *accum_advertising)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(tmp_supported);
        struct phylink_link_state tmp_state;

        linkmode_copy(tmp_supported, supported);

        tmp_state = *state;
        tmp_state.interface = interface;

        if (phy)
                tmp_state.rate_matching = phy_get_rate_matching(phy, interface);

        if (!phylink_validate_mac_and_pcs(pl, tmp_supported, &tmp_state)) {
                phylink_dbg(pl, " interface %u (%s) rate match %s supports %*pbl\n",
                            interface, phy_modes(interface),
                            phy_rate_matching_to_str(tmp_state.rate_matching),
                            __ETHTOOL_LINK_MODE_MASK_NBITS, tmp_supported);

                linkmode_or(accum_supported, accum_supported, tmp_supported);
                linkmode_or(accum_advertising, accum_advertising,
                            tmp_state.advertising);
        }
}

static int phylink_validate_mask(struct phylink *pl, struct phy_device *phy,
                                 unsigned long *supported,
                                 struct phylink_link_state *state,
                                 const unsigned long *interfaces)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(all_adv) = { 0, };
        __ETHTOOL_DECLARE_LINK_MODE_MASK(all_s) = { 0, };
        int interface;

        for_each_set_bit(interface, interfaces, PHY_INTERFACE_MODE_MAX)
                phylink_validate_one(pl, phy, supported, state, interface,
                                     all_s, all_adv);

        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)
{
        const unsigned long *interfaces = pl->config->supported_interfaces;

        if (state->interface == PHY_INTERFACE_MODE_NA)
                return phylink_validate_mask(pl, NULL, supported, state,
                                             interfaces);

        if (!test_bit(state->interface, interfaces))
                return -EINVAL;

        return phylink_validate_mac_and_pcs(pl, supported, state);
}

static void phylink_fill_fixedlink_supported(unsigned long *supported)
{
        linkmode_set_bit(ETHTOOL_LINK_MODE_Pause_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_2500baseT_Full_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_5000baseT_Full_BIT, supported);
        linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseT_Full_BIT, supported);
}

static int phylink_parse_fixedlink(struct phylink *pl,
                                   const struct fwnode_handle *fwnode)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(match) = { 0, };
        __ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
        const struct link_capabilities *c;
        struct fwnode_handle *fixed_node;
        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;
                }

                phylink_warn(pl, "%pfw uses deprecated array-style fixed-link binding!\n",
                             fwnode);

                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);

        linkmode_zero(pl->supported);
        phylink_fill_fixedlink_supported(pl->supported);

        linkmode_copy(pl->link_config.advertising, pl->supported);
        phylink_validate(pl, pl->supported, &pl->link_config);

        c = phy_caps_lookup(pl->link_config.speed, pl->link_config.duplex,
                            pl->supported, true);
        if (c)
                linkmode_and(match, pl->supported, c->linkmodes);

        linkmode_set_bit(ETHTOOL_LINK_MODE_Pause_BIT, mask);
        linkmode_set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, mask);
        linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, mask);
        linkmode_and(pl->supported, pl->supported, mask);

        phylink_set(pl->supported, MII);

        if (c) {
                linkmode_or(pl->supported, pl->supported, match);
                linkmode_or(pl->link_config.lp_advertising,
                            pl->link_config.lp_advertising, match);
        } 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,
                              const struct fwnode_handle *fwnode)
{
        struct fwnode_handle *dn;
        const char *managed;
        unsigned long caps;

        if (pl->config->default_an_inband)
                pl->cfg_link_an_mode = MLO_AN_INBAND;

        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)) {
                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;
                }

                pl->cfg_link_an_mode = MLO_AN_INBAND;
        }

        if (pl->cfg_link_an_mode == MLO_AN_INBAND) {
                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);

                switch (pl->link_config.interface) {
                case PHY_INTERFACE_MODE_SGMII:
                case PHY_INTERFACE_MODE_PSGMII:
                case PHY_INTERFACE_MODE_QSGMII:
                case PHY_INTERFACE_MODE_QUSGMII:
                case PHY_INTERFACE_MODE_RGMII:
                case PHY_INTERFACE_MODE_RGMII_ID:
                case PHY_INTERFACE_MODE_RGMII_RXID:
                case PHY_INTERFACE_MODE_RGMII_TXID:
                case PHY_INTERFACE_MODE_RTBI:
                case PHY_INTERFACE_MODE_1000BASEX:
                case PHY_INTERFACE_MODE_2500BASEX:
                case PHY_INTERFACE_MODE_5GBASER:
                case PHY_INTERFACE_MODE_25GBASER:
                case PHY_INTERFACE_MODE_USXGMII:
                case PHY_INTERFACE_MODE_10G_QXGMII:
                case PHY_INTERFACE_MODE_10GKR:
                case PHY_INTERFACE_MODE_10GBASER:
                case PHY_INTERFACE_MODE_XLGMII:
                case PHY_INTERFACE_MODE_50GBASER:
                case PHY_INTERFACE_MODE_LAUI:
                case PHY_INTERFACE_MODE_100GBASEP:
                        caps = ~(MAC_SYM_PAUSE | MAC_ASYM_PAUSE);
                        caps = phylink_get_capabilities(pl->link_config.interface, caps,
                                                        RATE_MATCH_NONE);
                        phylink_caps_to_linkmodes(pl->supported, caps);
                        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;
                }
        }

        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 (!linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                               state->advertising))
                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_an_pause(struct phylink_link_state *state)
{
        bool tx_pause, rx_pause;

        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 unsigned int phylink_pcs_inband_caps(struct phylink_pcs *pcs,
                                    phy_interface_t interface)
{
        if (pcs && pcs->ops->pcs_inband_caps)
                return pcs->ops->pcs_inband_caps(pcs, interface);

        return 0;
}

static void phylink_pcs_pre_config(struct phylink_pcs *pcs,
                                   phy_interface_t interface)
{
        if (pcs && pcs->ops->pcs_pre_config)
                pcs->ops->pcs_pre_config(pcs, interface);
}

static int phylink_pcs_post_config(struct phylink_pcs *pcs,
                                   phy_interface_t interface)
{
        int err = 0;

        if (pcs && pcs->ops->pcs_post_config)
                err = pcs->ops->pcs_post_config(pcs, interface);

        return err;
}

static void phylink_pcs_disable(struct phylink_pcs *pcs)
{
        if (pcs && pcs->ops->pcs_disable)
                pcs->ops->pcs_disable(pcs);
}

static int phylink_pcs_enable(struct phylink_pcs *pcs)
{
        int err = 0;

        if (pcs && pcs->ops->pcs_enable)
                err = pcs->ops->pcs_enable(pcs);

        return err;
}

static int phylink_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
                              const struct phylink_link_state *state,
                              bool permit_pause_to_mac)
{
        if (!pcs)
                return 0;

        return pcs->ops->pcs_config(pcs, neg_mode, state->interface,
                                    state->advertising, permit_pause_to_mac);
}

static void phylink_pcs_link_up(struct phylink_pcs *pcs, unsigned int neg_mode,
                                phy_interface_t interface, int speed,
                                int duplex)
{
        if (pcs && pcs->ops->pcs_link_up)
                pcs->ops->pcs_link_up(pcs, neg_mode, interface, speed, duplex);
}

static void phylink_pcs_disable_eee(struct phylink_pcs *pcs)
{
        if (pcs && pcs->ops->pcs_disable_eee)
                pcs->ops->pcs_disable_eee(pcs);
}

static void phylink_pcs_enable_eee(struct phylink_pcs *pcs)
{
        if (pcs && pcs->ops->pcs_enable_eee)
                pcs->ops->pcs_enable_eee(pcs);
}

/* Query inband for a specific interface mode, asking the MAC for the
 * PCS which will be used to handle the interface mode.
 */
static unsigned int phylink_inband_caps(struct phylink *pl,
                                         phy_interface_t interface)
{
        struct phylink_pcs *pcs;

        if (!pl->mac_ops->mac_select_pcs)
                return 0;

        pcs = pl->mac_ops->mac_select_pcs(pl->config, interface);
        if (!pcs)
                return 0;

        return phylink_pcs_inband_caps(pcs, interface);
}

static void phylink_pcs_poll_stop(struct phylink *pl)
{
        if (pl->cfg_link_an_mode == MLO_AN_INBAND)
                timer_delete(&pl->link_poll);
}

static void phylink_pcs_poll_start(struct phylink *pl)
{
        if (pl->pcs && pl->pcs->poll && pl->cfg_link_an_mode == MLO_AN_INBAND)
                mod_timer(&pl->link_poll, jiffies + HZ);
}

int phylink_pcs_pre_init(struct phylink *pl, struct phylink_pcs *pcs)
{
        int ret = 0;

        /* Signal to PCS driver that MAC requires RX clock for init */
        if (pl->config->mac_requires_rxc)
                pcs->rxc_always_on = true;

        if (pcs->ops->pcs_pre_init)
                ret = pcs->ops->pcs_pre_init(pcs);

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_pcs_pre_init);

static void phylink_mac_config(struct phylink *pl,
                               const struct phylink_link_state *state)
{
        struct phylink_link_state st = *state;

        /* Stop drivers incorrectly using these */
        linkmode_zero(st.lp_advertising);
        st.speed = SPEED_UNKNOWN;
        st.duplex = DUPLEX_UNKNOWN;
        st.an_complete = false;
        st.link = false;

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

        pl->mac_ops->mac_config(pl->config, pl->act_link_an_mode, &st);
}

static void phylink_pcs_an_restart(struct phylink *pl)
{
        if (pl->pcs && linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                         pl->link_config.advertising) &&
            phy_interface_mode_is_8023z(pl->link_config.interface) &&
            phylink_autoneg_inband(pl->act_link_an_mode))
                pl->pcs->ops->pcs_an_restart(pl->pcs);
}

enum inband_type {
        INBAND_NONE,
        INBAND_CISCO_SGMII,
        INBAND_BASEX,
};

static enum inband_type phylink_get_inband_type(phy_interface_t interface)
{
        switch (interface) {
        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_QSGMII:
        case PHY_INTERFACE_MODE_QUSGMII:
        case PHY_INTERFACE_MODE_USXGMII:
        case PHY_INTERFACE_MODE_10G_QXGMII:
                /* These protocols are designed for use with a PHY which
                 * communicates its negotiation result back to the MAC via
                 * inband communication. Note: there exist PHYs that run
                 * with SGMII but do not send the inband data.
                 */
                return INBAND_CISCO_SGMII;

        case PHY_INTERFACE_MODE_1000BASEX:
        case PHY_INTERFACE_MODE_2500BASEX:
                /* 1000base-X is designed for use media-side for Fibre
                 * connections, and thus the Autoneg bit needs to be
                 * taken into account. We also do this for 2500base-X
                 * as well, but drivers may not support this, so may
                 * need to override this.
                 */
                return INBAND_BASEX;

        default:
                return INBAND_NONE;
        }
}

/**
 * phylink_pcs_neg_mode() - helper to determine PCS inband mode
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @pcs: a pointer to &struct phylink_pcs
 * @interface: interface mode to be used
 * @advertising: adertisement ethtool link mode mask
 *
 * Determines the negotiation mode to be used by the PCS, and returns
 * one of:
 *
 * - %PHYLINK_PCS_NEG_NONE: interface mode does not support inband
 * - %PHYLINK_PCS_NEG_OUTBAND: an out of band mode (e.g. reading the PHY)
 *   will be used.
 * - %PHYLINK_PCS_NEG_INBAND_DISABLED: inband mode selected but autoneg
 *   disabled
 * - %PHYLINK_PCS_NEG_INBAND_ENABLED: inband mode selected and autoneg enabled
 *
 * Note: this is for cases where the PCS itself is involved in negotiation
 * (e.g. Clause 37, SGMII and similar) not Clause 73.
 */
static void phylink_pcs_neg_mode(struct phylink *pl, struct phylink_pcs *pcs,
                                 phy_interface_t interface,
                                 const unsigned long *advertising)
{
        unsigned int pcs_ib_caps = 0;
        unsigned int phy_ib_caps = 0;
        unsigned int neg_mode, mode;
        enum inband_type type;

        type = phylink_get_inband_type(interface);
        if (type == INBAND_NONE) {
                pl->pcs_neg_mode = PHYLINK_PCS_NEG_NONE;
                pl->act_link_an_mode = pl->req_link_an_mode;
                return;
        }

        mode = pl->req_link_an_mode;

        pl->phy_ib_mode = 0;

        if (pcs)
                pcs_ib_caps = phylink_pcs_inband_caps(pcs, interface);

        if (pl->phydev)
                phy_ib_caps = phy_inband_caps(pl->phydev, interface);

        phylink_dbg(pl, "interface %s inband modes: pcs=%02x phy=%02x\n",
                    phy_modes(interface), pcs_ib_caps, phy_ib_caps);

        if (!phylink_autoneg_inband(mode)) {
                bool pcs_ib_only = false;
                bool phy_ib_only = false;

                if (pcs_ib_caps && pcs_ib_caps != LINK_INBAND_DISABLE) {
                        /* PCS supports reporting in-band capabilities, and
                         * supports more than disable mode.
                         */
                        if (pcs_ib_caps & LINK_INBAND_DISABLE)
                                neg_mode = PHYLINK_PCS_NEG_OUTBAND;
                        else if (pcs_ib_caps & LINK_INBAND_ENABLE)
                                pcs_ib_only = true;
                }

                if (phy_ib_caps && phy_ib_caps != LINK_INBAND_DISABLE) {
                        /* PHY supports in-band capabilities, and supports
                         * more than disable mode.
                         */
                        if (phy_ib_caps & LINK_INBAND_DISABLE)
                                pl->phy_ib_mode = LINK_INBAND_DISABLE;
                        else if (phy_ib_caps & LINK_INBAND_BYPASS)
                                pl->phy_ib_mode = LINK_INBAND_BYPASS;
                        else if (phy_ib_caps & LINK_INBAND_ENABLE)
                                phy_ib_only = true;
                }

                /* If either the PCS or PHY requires inband to be enabled,
                 * this is an invalid configuration. Provide a diagnostic
                 * message for this case, but don't try to force the issue.
                 */
                if (pcs_ib_only || phy_ib_only)
                        phylink_warn(pl,
                                     "firmware wants %s mode, but %s%s%s requires inband\n",
                                     phylink_an_mode_str(mode),
                                     pcs_ib_only ? "PCS" : "",
                                     pcs_ib_only && phy_ib_only ? " and " : "",
                                     phy_ib_only ? "PHY" : "");

                neg_mode = PHYLINK_PCS_NEG_OUTBAND;
        } else if (type == INBAND_CISCO_SGMII || pl->phydev) {
                /* For SGMII modes which are designed to be used with PHYs, or
                 * Base-X with a PHY, we try to use in-band mode where-ever
                 * possible. However, there are some PHYs e.g. BCM84881 which
                 * do not support in-band.
                 */
                const unsigned int inband_ok = LINK_INBAND_ENABLE |
                                               LINK_INBAND_BYPASS;
                const unsigned int outband_ok = LINK_INBAND_DISABLE |
                                                LINK_INBAND_BYPASS;
                /* PCS  PHY
                 * D E  D E
                 * 0 0  0 0     no information                  inband enabled
                 * 1 0  0 0     pcs doesn't support             outband
                 * 0 1  0 0     pcs required                    inband enabled
                 * 1 1  0 0     pcs optional                    inband enabled
                 * 0 0  1 0     phy doesn't support             outband
                 * 1 0  1 0     pcs+phy doesn't support         outband
                 * 0 1  1 0     pcs required, phy doesn't support, invalid
                 * 1 1  1 0     pcs optional, phy doesn't support, outband
                 * 0 0  0 1     phy required                    inband enabled
                 * 1 0  0 1     pcs doesn't support, phy required, invalid
                 * 0 1  0 1     pcs+phy required                inband enabled
                 * 1 1  0 1     pcs optional, phy required      inband enabled
                 * 0 0  1 1     phy optional                    inband enabled
                 * 1 0  1 1     pcs doesn't support, phy optional, outband
                 * 0 1  1 1     pcs required, phy optional      inband enabled
                 * 1 1  1 1     pcs+phy optional                inband enabled
                 */
                if ((!pcs_ib_caps || pcs_ib_caps & inband_ok) &&
                    (!phy_ib_caps || phy_ib_caps & inband_ok)) {
                        /* In-band supported or unknown at both ends. Enable
                         * in-band mode with or without bypass at the PHY.
                         */
                        if (phy_ib_caps & LINK_INBAND_ENABLE)
                                pl->phy_ib_mode = LINK_INBAND_ENABLE;
                        else if (phy_ib_caps & LINK_INBAND_BYPASS)
                                pl->phy_ib_mode = LINK_INBAND_BYPASS;

                        neg_mode = PHYLINK_PCS_NEG_INBAND_ENABLED;
                } else if ((!pcs_ib_caps || pcs_ib_caps & outband_ok) &&
                           (!phy_ib_caps || phy_ib_caps & outband_ok)) {
                        /* Either in-band not supported at at least one end.
                         * In-band bypass at the other end is possible.
                         */
                        if (phy_ib_caps & LINK_INBAND_DISABLE)
                                pl->phy_ib_mode = LINK_INBAND_DISABLE;
                        else if (phy_ib_caps & LINK_INBAND_BYPASS)
                                pl->phy_ib_mode = LINK_INBAND_BYPASS;

                        neg_mode = PHYLINK_PCS_NEG_OUTBAND;
                        if (pl->phydev)
                                mode = MLO_AN_PHY;
                } else {
                        /* invalid */
                        phylink_warn(pl, "%s: incompatible in-band capabilities, trying in-band",
                                     phy_modes(interface));
                        neg_mode = PHYLINK_PCS_NEG_INBAND_ENABLED;
                }
        } else {
                /* For Base-X without a PHY */
                if (pcs_ib_caps == LINK_INBAND_DISABLE)
                        /* If the PCS doesn't support inband, then inband must
                         * be disabled.
                         */
                        neg_mode = PHYLINK_PCS_NEG_INBAND_DISABLED;
                else if (pcs_ib_caps == LINK_INBAND_ENABLE)
                        /* If the PCS requires inband, then inband must always
                         * be enabled.
                         */
                        neg_mode = PHYLINK_PCS_NEG_INBAND_ENABLED;
                else if (linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                           advertising))
                        neg_mode = PHYLINK_PCS_NEG_INBAND_ENABLED;
                else
                        neg_mode = PHYLINK_PCS_NEG_INBAND_DISABLED;
        }

        pl->pcs_neg_mode = neg_mode;
        pl->act_link_an_mode = mode;
}

static void phylink_major_config(struct phylink *pl, bool restart,
                                  const struct phylink_link_state *state)
{
        struct phylink_pcs *pcs = NULL;
        bool pcs_changed = false;
        unsigned int rate_kbd;
        int err;

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

        pl->major_config_failed = false;

        if (pl->mac_ops->mac_select_pcs) {
                pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
                if (IS_ERR(pcs)) {
                        phylink_err(pl,
                                    "mac_select_pcs unexpectedly failed: %pe\n",
                                    pcs);

                        pl->major_config_failed = true;
                        return;
                }

                pcs_changed = pl->pcs != pcs;
        }

        phylink_pcs_neg_mode(pl, pcs, state->interface, state->advertising);

        phylink_dbg(pl, "major config, active %s/%s/%s\n",
                    phylink_an_mode_str(pl->act_link_an_mode),
                    phylink_pcs_mode_str(pl->pcs_neg_mode),
                    phy_modes(state->interface));

        phylink_pcs_poll_stop(pl);

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

        /* If we have a new PCS, switch to the new PCS after preparing the MAC
         * for the change.
         */
        if (pcs_changed) {
                phylink_pcs_disable(pl->pcs);

                if (pl->pcs)
                        pl->pcs->phylink = NULL;

                if (pcs)
                        pcs->phylink = pl;

                pl->pcs = pcs;
        }

        if (pl->pcs)
                phylink_pcs_pre_config(pl->pcs, state->interface);

        phylink_mac_config(pl, state);

        if (pl->pcs) {
                err = phylink_pcs_post_config(pl->pcs, state->interface);
                if (err < 0) {
                        phylink_err(pl, "pcs_post_config failed: %pe\n",
                                    ERR_PTR(err));

                        pl->major_config_failed = true;
                }
        }

        if (pl->pcs_state == PCS_STATE_STARTING || pcs_changed)
                phylink_pcs_enable(pl->pcs);

        err = phylink_pcs_config(pl->pcs, pl->pcs_neg_mode, state,
                                 !!(pl->link_config.pause & MLO_PAUSE_AN));
        if (err < 0) {
                phylink_err(pl, "pcs_config failed: %pe\n", ERR_PTR(err));
                pl->major_config_failed = true;
        } else if (err > 0) {
                restart = true;
        }

        if (restart)
                phylink_pcs_an_restart(pl);

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

                        pl->major_config_failed = true;
                }
        }

        if (pl->phydev && pl->phy_ib_mode) {
                err = phy_config_inband(pl->phydev, pl->phy_ib_mode);
                if (err < 0) {
                        phylink_err(pl, "phy_config_inband: %pe\n",
                                    ERR_PTR(err));

                        pl->major_config_failed = true;
                }
        }

        if (pl->sfp_bus) {
                rate_kbd = phylink_interface_signal_rate(state->interface);
                if (rate_kbd)
                        sfp_upstream_set_signal_rate(pl->sfp_bus, rate_kbd);
        }

        phylink_pcs_poll_start(pl);
}

/*
 * 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;

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

        /* Recompute the PCS neg mode */
        phylink_pcs_neg_mode(pl, pl->pcs, pl->link_config.interface,
                             pl->link_config.advertising);

        /* 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 = phylink_pcs_config(pl->pcs, pl->pcs_neg_mode, &pl->link_config,
                                 !!(pl->link_config.pause & MLO_PAUSE_AN));
        if (ret < 0)
                return ret;

        if (ret > 0)
                phylink_pcs_an_restart(pl);

        return 0;
}

static void phylink_mac_pcs_get_state(struct phylink *pl,
                                      struct phylink_link_state *state)
{
        struct phylink_pcs *pcs;
        bool autoneg;

        linkmode_copy(state->advertising, pl->link_config.advertising);
        linkmode_zero(state->lp_advertising);
        state->interface = pl->link_config.interface;
        state->rate_matching = pl->link_config.rate_matching;
        state->an_complete = 0;
        state->link = 1;

        autoneg = pl->pcs_neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED;
        if (autoneg) {
                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;
        }

        pcs = pl->pcs;
        if (pcs)
                pcs->ops->pcs_get_state(pcs, pl->pcs_neg_mode, 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);

        state->pause = MLO_PAUSE_NONE;
        phylink_resolve_an_pause(state);
}

static void phylink_mac_initial_config(struct phylink *pl, bool force_restart)
{
        struct phylink_link_state link_state;
        struct phy_device *phy = pl->phydev;

        switch (pl->req_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);
        if (phy)
                mutex_lock(&phy->lock);
        phylink_major_config(pl, force_restart, &link_state);
        if (phy)
                mutex_unlock(&phy->lock);
}

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_deactivate_lpi(struct phylink *pl)
{
        if (pl->mac_enable_tx_lpi) {
                pl->mac_enable_tx_lpi = false;

                phylink_dbg(pl, "disabling LPI\n");

                pl->mac_ops->mac_disable_tx_lpi(pl->config);

                phylink_pcs_disable_eee(pl->pcs);
        }
}

static void phylink_activate_lpi(struct phylink *pl)
{
        int err;

        if (!test_bit(pl->cur_interface, pl->config->lpi_interfaces)) {
                phylink_dbg(pl, "MAC does not support LPI with %s\n",
                            phy_modes(pl->cur_interface));
                return;
        }

        phylink_dbg(pl, "LPI timer %uus, tx clock stop %u\n",
                    pl->mac_tx_lpi_timer, pl->mac_tx_clk_stop);

        phylink_pcs_enable_eee(pl->pcs);

        err = pl->mac_ops->mac_enable_tx_lpi(pl->config, pl->mac_tx_lpi_timer,
                                             pl->mac_tx_clk_stop);
        if (err) {
                phylink_pcs_disable_eee(pl->pcs);
                phylink_err(pl, "%ps() failed: %pe\n",
                            pl->mac_ops->mac_enable_tx_lpi, ERR_PTR(err));
                return;
        }

        pl->mac_enable_tx_lpi = true;
}

static void phylink_link_up(struct phylink *pl,
                            struct phylink_link_state link_state)
{
        struct net_device *ndev = pl->netdev;
        int speed, duplex;
        bool rx_pause;

        speed = link_state.speed;
        duplex = link_state.duplex;
        rx_pause = !!(link_state.pause & MLO_PAUSE_RX);

        switch (link_state.rate_matching) {
        case RATE_MATCH_PAUSE:
                /* The PHY is doing rate matchion from the media rate (in
                 * the link_state) to the interface speed, and will send
                 * pause frames to the MAC to limit its transmission speed.
                 */
                speed = phylink_interface_max_speed(link_state.interface);
                duplex = DUPLEX_FULL;
                rx_pause = true;
                break;

        case RATE_MATCH_CRS:
                /* The PHY is doing rate matchion from the media rate (in
                 * the link_state) to the interface speed, and will cause
                 * collisions to the MAC to limit its transmission speed.
                 */
                speed = phylink_interface_max_speed(link_state.interface);
                duplex = DUPLEX_HALF;
                break;
        }

        pl->cur_interface = link_state.interface;

        phylink_pcs_link_up(pl->pcs, pl->pcs_neg_mode, pl->cur_interface, speed,
                            duplex);

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

        if (pl->mac_supports_eee && pl->phy_enable_tx_lpi)
                phylink_activate_lpi(pl);

        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);

        phylink_deactivate_lpi(pl);

        pl->mac_ops->mac_link_down(pl->config, pl->act_link_an_mode,
                                   pl->cur_interface);
        phylink_info(pl, "Link is Down\n");
}

static bool phylink_link_is_up(struct phylink *pl)
{
        return pl->netdev ? netif_carrier_ok(pl->netdev) : pl->old_link_state;
}

static void phylink_resolve(struct work_struct *w)
{
        struct phylink *pl = container_of(w, struct phylink, resolve);
        struct phylink_link_state link_state;
        bool mac_config = false;
        bool retrigger = false;
        struct phy_device *phy;
        bool cur_link_state;

        mutex_lock(&pl->phydev_mutex);
        phy = pl->phydev;
        if (phy)
                mutex_lock(&phy->lock);
        mutex_lock(&pl->state_mutex);
        cur_link_state = phylink_link_is_up(pl);

        if (pl->phylink_disable_state) {
                pl->link_failed = false;
                link_state.link = false;
        } else if (pl->link_failed) {
                link_state.link = false;
                retrigger = true;
        } else if (pl->act_link_an_mode == MLO_AN_FIXED) {
                phylink_get_fixed_state(pl, &link_state);
                mac_config = link_state.link;
        } else if (pl->act_link_an_mode == MLO_AN_PHY) {
                link_state = pl->phy_state;
                mac_config = link_state.link;
        } else {
                phylink_mac_pcs_get_state(pl, &link_state);

                /* The PCS may have a latching link-fail indicator. If the link
                 * was up, bring the link down and re-trigger the resolve.
                 * Otherwise, re-read the PCS state to get the current status
                 * of the link.
                 */
                if (!link_state.link) {
                        if (cur_link_state)
                                retrigger = true;
                        else
                                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 (phy)
                        link_state.link &= pl->phy_state.link;

                /* Only update if the PHY link is up */
                if (phy && pl->phy_state.link) {
                        /* If the interface has changed, force a link down
                         * event if the link isn't already down, and re-resolve.
                         */
                        if (link_state.interface != pl->phy_state.interface) {
                                retrigger = true;
                                link_state.link = false;
                        }

                        link_state.interface = pl->phy_state.interface;

                        /* If we are doing rate matching, then the link
                         * speed/duplex comes from the PHY
                         */
                        if (pl->phy_state.rate_matching) {
                                link_state.rate_matching =
                                        pl->phy_state.rate_matching;
                                link_state.speed = pl->phy_state.speed;
                                link_state.duplex = pl->phy_state.duplex;
                        }

                        /* 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;
                }
        }

        if (pl->act_link_an_mode != MLO_AN_FIXED)
                phylink_apply_manual_flow(pl, &link_state);

        if ((mac_config && link_state.interface != pl->link_config.interface) ||
            pl->force_major_config) {
                /* The interface has changed or a forced major configuration
                 * was requested, so 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;
                pl->force_major_config = false;
        }

        /* If configuration of the interface failed, force the link down
         * until we get a successful configuration.
         */
        if (pl->major_config_failed)
                link_state.link = false;

        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 && retrigger) {
                pl->link_failed = false;
                queue_work(system_power_efficient_wq, &pl->resolve);
        }
        mutex_unlock(&pl->state_mutex);
        if (phy)
                mutex_unlock(&phy->lock);
        mutex_unlock(&pl->phydev_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_enable_and_run_resolve(struct phylink *pl, int bit)
{
        clear_bit(bit, &pl->phylink_disable_state);
        phylink_run_resolve(pl);
}

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,
                                const struct fwnode_handle *fwnode)
{
        struct sfp_bus *bus;
        int ret;

        if (!fwnode)
                return 0;

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

        pl->sfp_bus = bus;

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

        return ret;
}

/**
 * phylink_set_fixed_link() - set the fixed link
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 * @state: a pointer to a struct phylink_link_state.
 *
 * This function is used when the link parameters are known and do not change,
 * making it suitable for certain types of network connections.
 *
 * Returns: zero on success or negative error code.
 */
int phylink_set_fixed_link(struct phylink *pl,
                           const struct phylink_link_state *state)
{
        const struct link_capabilities *c;
        unsigned long *adv;

        if (pl->cfg_link_an_mode != MLO_AN_PHY || !state ||
            !test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state))
                return -EINVAL;

        c = phy_caps_lookup(state->speed, state->duplex,
                            pl->supported, true);
        if (!c)
                return -EINVAL;

        adv = pl->link_config.advertising;
        linkmode_and(adv, pl->supported, c->linkmodes);
        linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, adv);

        pl->link_config.speed = state->speed;
        pl->link_config.duplex = state->duplex;
        pl->link_config.link = 1;
        pl->link_config.an_complete = 1;

        pl->cfg_link_an_mode = MLO_AN_FIXED;
        pl->req_link_an_mode = pl->cfg_link_an_mode;

        return 0;
}
EXPORT_SYMBOL_GPL(phylink_set_fixed_link);

/**
 * 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,
                               const struct fwnode_handle *fwnode,
                               phy_interface_t iface,
                               const struct phylink_mac_ops *mac_ops)
{
        struct phylink *pl;
        int ret;

        /* Validate the supplied configuration */
        if (phy_interface_empty(config->supported_interfaces)) {
                dev_err(config->dev,
                        "phylink: error: empty supported_interfaces\n");
                return ERR_PTR(-EINVAL);
        }

        pl = kzalloc_obj(*pl);
        if (!pl)
                return ERR_PTR(-ENOMEM);

        mutex_init(&pl->phydev_mutex);
        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);
                netif_carrier_off(pl->netdev);
        } else if (config->type == PHYLINK_DEV) {
                pl->dev = config->dev;
        } else {
                kfree(pl);
                return ERR_PTR(-EINVAL);
        }

        pl->mac_supports_eee_ops = phylink_mac_implements_lpi(mac_ops);
        pl->mac_supports_eee = pl->mac_supports_eee_ops &&
                               pl->config->lpi_capabilities &&
                               !phy_interface_empty(pl->config->lpi_interfaces);

        /* Set the default EEE configuration */
        pl->eee_cfg.eee_enabled = pl->config->eee_enabled_default;
        pl->eee_cfg.tx_lpi_enabled = pl->eee_cfg.eee_enabled;
        pl->eee_cfg.tx_lpi_timer = pl->config->lpi_timer_default;

        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->pcs_state = PCS_STATE_DOWN;
        pl->mac_ops = mac_ops;
        __set_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
        timer_setup(&pl->link_poll, phylink_fixed_poll, 0);

        linkmode_fill(pl->supported);
        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->req_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_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);

/**
 * phylink_expects_phy() - Determine if phylink expects a phy to be attached
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * When using fixed-link mode, or in-band mode with 1000base-X or 2500base-X,
 * no PHY is needed.
 *
 * Returns true if phylink will be expecting a PHY.
 */
bool phylink_expects_phy(struct phylink *pl)
{
        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 false;
        return true;
}
EXPORT_SYMBOL_GPL(phylink_expects_phy);

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.rate_matching = phydev->rate_matching;
        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;
        if (!up)
                pl->link_failed = true;

        /* Get the LPI state from phylib */
        pl->phy_enable_tx_lpi = phydev->enable_tx_lpi;
        pl->mac_tx_lpi_timer = phydev->eee_cfg.tx_lpi_timer;
        mutex_unlock(&pl->state_mutex);

        phylink_run_resolve(pl);

        phylink_dbg(pl, "phy link %s %s/%s/%s/%s/%s/%slpi\n",
                    up ? "up" : "down",
                    phy_modes(phydev->interface),
                    phy_speed_to_str(phydev->speed),
                    phy_duplex_to_str(phydev->duplex),
                    phy_rate_matching_to_str(phydev->rate_matching),
                    phylink_pause_to_str(pl->phy_state.pause),
                    phydev->enable_tx_lpi ? "" : "no");
}

static int phylink_validate_phy(struct phylink *pl, struct phy_device *phy,
                                unsigned long *supported,
                                struct phylink_link_state *state)
{
        DECLARE_PHY_INTERFACE_MASK(interfaces);

        /* If the PHY provides a bitmap of the interfaces it will be using
         * depending on the negotiated media speeds, use this to validate
         * which ethtool link modes can be used.
         */
        if (!phy_interface_empty(phy->possible_interfaces)) {
                /* We only care about the union of the PHY's interfaces and
                 * those which the host supports.
                 */
                phy_interface_and(interfaces, phy->possible_interfaces,
                                  pl->config->supported_interfaces);

                if (phy_interface_empty(interfaces)) {
                        phylink_err(pl, "PHY has no common interfaces\n");
                        return -EINVAL;
                }

                if (phy_on_sfp(phy)) {
                        /* If the PHY is on a SFP, limit the interfaces to
                         * those that can be used with a SFP module.
                         */
                        phy_interface_and(interfaces, interfaces,
                                          phylink_sfp_interfaces);

                        if (phy_interface_empty(interfaces)) {
                                phylink_err(pl, "SFP PHY's possible interfaces becomes empty\n");
                                return -EINVAL;
                        }
                }

                phylink_dbg(pl, "PHY %s uses interfaces %*pbl, validating %*pbl\n",
                            phydev_name(phy),
                            (int)PHY_INTERFACE_MODE_MAX,
                            phy->possible_interfaces,
                            (int)PHY_INTERFACE_MODE_MAX, interfaces);

                return phylink_validate_mask(pl, phy, supported, state,
                                             interfaces);
        }

        phylink_dbg(pl, "PHY %s doesn't supply possible interfaces\n",
                    phydev_name(phy));

        /* Check whether we would use rate matching for the proposed interface
         * mode.
         */
        state->rate_matching = phy_get_rate_matching(phy, state->interface);

        /* Clause 45 PHYs may switch their Serdes lane between, e.g. 10GBASE-R,
         * 5GBASE-R, 2500BASE-X and SGMII if they are not using rate matching.
         * For some interface modes (e.g. RXAUI, XAUI and USXGMII) switching
         * their Serdes is either unnecessary or not reasonable.
         *
         * For these which switch interface modes, we really need to know which
         * interface modes the PHY supports to properly work out which ethtool
         * linkmodes can be supported. For now, as a work-around, we validate
         * against all interface modes, which may lead to more ethtool link
         * modes being advertised than are actually supported.
         */
        if (phy->is_c45 && state->rate_matching == RATE_MATCH_NONE &&
            state->interface != PHY_INTERFACE_MODE_RXAUI &&
            state->interface != PHY_INTERFACE_MODE_XAUI &&
            state->interface != PHY_INTERFACE_MODE_USXGMII)
                state->interface = PHY_INTERFACE_MODE_NA;

        return phylink_validate(pl, supported, state);
}

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);
        config.interface = interface;

        ret = phylink_validate_phy(pl, phy, supported, &config);
        if (ret) {
                phylink_warn(pl, "validation of %s with support %*pb and advertisement %*pb failed: %pe\n",
                             phy_modes(config.interface),
                             __ETHTOOL_LINK_MODE_MASK_NBITS, phy->supported,
                             __ETHTOOL_LINK_MODE_MASK_NBITS, config.advertising,
                             ERR_PTR(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(&pl->phydev_mutex);
        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;
        pl->phy_state.rate_matching = RATE_MATCH_NONE;
        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);

        /* If the MAC supports phylink managed EEE, restrict the EEE
         * advertisement according to the MAC's LPI capabilities.
         */
        if (pl->mac_supports_eee) {
                /* If EEE is enabled, then we need to call phy_support_eee()
                 * to ensure that the advertising mask is appropriately set.
                 * This also enables EEE at the PHY.
                 */
                if (pl->eee_cfg.eee_enabled)
                        phy_support_eee(phy);

                phy->eee_cfg.tx_lpi_enabled = pl->eee_cfg.tx_lpi_enabled;
                phy->eee_cfg.tx_lpi_timer = pl->eee_cfg.tx_lpi_timer;

                /* Convert the MAC's LPI capabilities to linkmodes */
                linkmode_zero(pl->supported_lpi);
                phylink_caps_to_linkmodes(pl->supported_lpi,
                                          pl->config->lpi_capabilities);

                /* Restrict the PHYs EEE support/advertisement to the modes
                 * that the MAC supports.
                 */
                linkmode_and(phy->advertising_eee, phy->advertising_eee,
                             pl->supported_lpi);
        } else if (pl->mac_supports_eee_ops) {
                /* MAC supports phylink EEE, but wants EEE always disabled. */
                phy_disable_eee(phy);
        }

        mutex_unlock(&pl->state_mutex);
        mutex_unlock(&phy->lock);
        mutex_unlock(&pl->phydev_mutex);

        phylink_dbg(pl,
                    "phy: %s setting supported %*pb advertising %*pb\n",
                    phy_modes(interface),
                    __ETHTOOL_LINK_MODE_MASK_NBITS, pl->supported,
                    __ETHTOOL_LINK_MODE_MASK_NBITS, phy->advertising);

        if (pl->config->mac_managed_pm)
                phy->mac_managed_pm = true;

        /* Allow the MAC to stop its clock if the PHY has the capability */
        pl->mac_tx_clk_stop = phy_eee_tx_clock_stop_capable(phy) > 0;

        if (pl->mac_supports_eee_ops) {
                /* Explicitly configure whether the PHY is allowed to stop it's
                 * receive clock.
                 */
                ret = phy_eee_rx_clock_stop(phy,
                                            pl->config->eee_rx_clk_stop_enable);
                if (ret == -EOPNOTSUPP)
                        ret = 0;
        }

        if (ret == 0 && phy_interrupt_is_valid(phy))
                phy_request_interrupt(phy);

        return ret;
}

static int phylink_attach_phy(struct phylink *pl, struct phy_device *phy,
                              phy_interface_t interface)
{
        u32 flags = 0;

        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) && !pl->sfp_bus)))
                return -EINVAL;

        if (pl->phydev)
                return -EBUSY;

        if (pl->config->mac_requires_rxc)
                flags |= PHY_F_RXC_ALWAYS_ON;

        return phy_attach_direct(pl->netdev, phy, flags, 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,
                               const 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;

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

        if (pl->config->mac_requires_rxc)
                flags |= PHY_F_RXC_ALWAYS_ON;

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

        mutex_lock(&pl->phydev_mutex);
        phy = pl->phydev;
        if (phy) {
                mutex_lock(&phy->lock);
                mutex_lock(&pl->state_mutex);
                pl->phydev = NULL;
                pl->phy_enable_tx_lpi = false;
                pl->mac_tx_clk_stop = false;
                mutex_unlock(&pl->state_mutex);
                mutex_unlock(&phy->lock);
        }
        mutex_unlock(&pl->phydev_mutex);

        if (phy) {
                flush_work(&pl->resolve);
                phy_disconnect(phy);
        }
}
EXPORT_SYMBOL_GPL(phylink_disconnect_phy);

static void phylink_link_changed(struct phylink *pl, bool up, const char *what)
{
        if (!up)
                pl->link_failed = true;
        phylink_run_resolve(pl);
        phylink_dbg(pl, "%s link %s\n", what, up ? "up" : "down");
}

/**
 * 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)
{
        phylink_link_changed(pl, up, "mac");
}
EXPORT_SYMBOL_GPL(phylink_mac_change);

/**
 * phylink_pcs_change() - notify phylink of a change to PCS link state
 * @pcs: pointer to &struct phylink_pcs
 * @up: indicates whether the link is currently up.
 *
 * The PCS driver should call this when the state of its link changes
 * (e.g. link failure, new negotiation results, etc.) Note: it should
 * not determine "up" by reading the BMSR. If in doubt about the link
 * state at interrupt time, then pass true if pcs_get_state() returns
 * the latched link-down state, otherwise pass false.
 */
void phylink_pcs_change(struct phylink_pcs *pcs, bool up)
{
        struct phylink *pl = pcs->phylink;

        if (pl)
                phylink_link_changed(pl, up, "pcs");
}
EXPORT_SYMBOL_GPL(phylink_pcs_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->req_link_an_mode),
                     phy_modes(pl->link_config.interface));

        /* Always set the carrier off */
        if (pl->netdev)
                netif_carrier_off(pl->netdev);

        pl->pcs_state = PCS_STATE_STARTING;

        /* 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);

        pl->pcs_state = PCS_STATE_STARTED;

        phylink_enable_and_run_resolve(pl, PHYLINK_DISABLE_STOPPED);

        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;
        }

        if (pl->cfg_link_an_mode == MLO_AN_FIXED)
                poll |= pl->config->poll_fixed_state;

        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);
        timer_delete_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);

        pl->pcs_state = PCS_STATE_DOWN;

        phylink_pcs_disable(pl->pcs);
}
EXPORT_SYMBOL_GPL(phylink_stop);

/**
 * phylink_rx_clk_stop_block() - block PHY ability to stop receive clock in LPI
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Disable the PHY's ability to stop the receive clock while the receive path
 * is in EEE LPI state, until the number of calls to phylink_rx_clk_stop_block()
 * are balanced by calls to phylink_rx_clk_stop_unblock().
 */
void phylink_rx_clk_stop_block(struct phylink *pl)
{
        ASSERT_RTNL();

        if (pl->mac_rx_clk_stop_blocked == U8_MAX) {
                phylink_warn(pl, "%s called too many times - ignoring\n",
                             __func__);
                dump_stack();
                return;
        }

        /* Disable PHY receive clock stop if this is the first time this
         * function has been called and clock-stop was previously enabled.
         */
        if (pl->mac_rx_clk_stop_blocked++ == 0 &&
            pl->mac_supports_eee_ops && pl->phydev &&
            pl->config->eee_rx_clk_stop_enable)
                phy_eee_rx_clock_stop(pl->phydev, false);
}
EXPORT_SYMBOL_GPL(phylink_rx_clk_stop_block);

/**
 * phylink_rx_clk_stop_unblock() - unblock PHY ability to stop receive clock
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * All calls to phylink_rx_clk_stop_block() must be balanced with a
 * corresponding call to phylink_rx_clk_stop_unblock() to restore the PHYs
 * ability to stop the receive clock when the receive path is in EEE LPI mode.
 */
void phylink_rx_clk_stop_unblock(struct phylink *pl)
{
        ASSERT_RTNL();

        if (pl->mac_rx_clk_stop_blocked == 0) {
                phylink_warn(pl, "%s called too many times - ignoring\n",
                             __func__);
                dump_stack();
                return;
        }

        /* Re-enable PHY receive clock stop if the number of unblocks matches
         * the number of calls to the block function above.
         */
        if (--pl->mac_rx_clk_stop_blocked == 0 &&
            pl->mac_supports_eee_ops && pl->phydev &&
            pl->config->eee_rx_clk_stop_enable)
                phy_eee_rx_clock_stop(pl->phydev, true);
}
EXPORT_SYMBOL_GPL(phylink_rx_clk_stop_unblock);

static bool phylink_mac_supports_wol(struct phylink *pl)
{
        return !!pl->mac_ops->mac_wol_set;
}

static bool phylink_phy_supports_wol(struct phylink *pl,
                                     struct phy_device *phydev)
{
        return phydev && (pl->config->wol_phy_legacy || phy_can_wakeup(phydev));
}

static bool phylink_phy_pm_speed_ctrl(struct phylink *pl)
{
        return pl->config->wol_phy_speed_ctrl && !pl->wolopts_mac &&
               pl->phydev && phy_may_wakeup(pl->phydev);
}

/**
 * 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.
 *
 * Note: when phylink managed Wake-on-Lan is in use, @mac_wol is ignored.
 * (struct phylink_mac_ops.mac_set_wol populated.)
 */
void phylink_suspend(struct phylink *pl, bool mac_wol)
{
        ASSERT_RTNL();

        if (phylink_mac_supports_wol(pl))
                mac_wol = !!pl->wolopts_mac;

        if (mac_wol && (!pl->netdev || pl->netdev->ethtool->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);

                pl->suspend_link_up = phylink_link_is_up(pl);
                if (pl->suspend_link_up) {
                        /* 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);
                        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);
        }

        if (phylink_phy_pm_speed_ctrl(pl))
                phylink_speed_down(pl, false);
}
EXPORT_SYMBOL_GPL(phylink_suspend);

/**
 * phylink_prepare_resume() - prepare to resume a network device
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Optional, but if called must be called prior to phylink_resume().
 *
 * Prepare to resume a network device, preparing the PHY as necessary.
 */
void phylink_prepare_resume(struct phylink *pl)
{
        struct phy_device *phydev = pl->phydev;

        ASSERT_RTNL();

        /* IEEE 802.3 22.2.4.1.5 allows PHYs to stop their receive clock
         * when PDOWN is set. However, some MACs require RXC to be running
         * in order to resume. If the MAC requires RXC, and we have a PHY,
         * then resume the PHY. Note that 802.3 allows PHYs 500ms before
         * the clock meets requirements. We do not implement this delay.
         */
        if (pl->config->mac_requires_rxc && phydev && phydev->suspended)
                phy_resume(phydev);
}
EXPORT_SYMBOL_GPL(phylink_prepare_resume);

/**
 * 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 (phylink_phy_pm_speed_ctrl(pl))
                phylink_speed_up(pl);

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

                if (pl->suspend_link_up) {
                        /* 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 */
                phylink_enable_and_run_resolve(pl, PHYLINK_DISABLE_MAC_WOL);
        } 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 (phylink_mac_supports_wol(pl)) {
                if (phylink_phy_supports_wol(pl, pl->phydev))
                        phy_ethtool_get_wol(pl->phydev, wol);

                /* Where the MAC augments the WoL support, merge its support and
                 * current configuration.
                 */
                if (~wol->wolopts & pl->wolopts_mac & WAKE_MAGICSECURE)
                        memcpy(wol->sopass, pl->wol_sopass,
                               sizeof(wol->sopass));

                wol->supported |= pl->config->wol_mac_support;
                wol->wolopts |= pl->wolopts_mac;
        } else {
                /* Legacy */
                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)
{
        struct ethtool_wolinfo w = { .cmd = ETHTOOL_GWOL };
        int ret = -EOPNOTSUPP;
        bool changed;
        u32 wolopts;

        ASSERT_RTNL();

        if (phylink_mac_supports_wol(pl)) {
                wolopts = wol->wolopts;

                if (phylink_phy_supports_wol(pl, pl->phydev)) {
                        ret = phy_ethtool_set_wol(pl->phydev, wol);
                        if (ret != 0 && ret != -EOPNOTSUPP)
                                return ret;

                        phy_ethtool_get_wol(pl->phydev, &w);

                        /* Any Wake-on-Lan modes which the PHY is handling
                         * should not be passed on to the MAC.
                         */
                        wolopts &= ~w.wolopts;
                }

                wolopts &= pl->config->wol_mac_support;
                changed = pl->wolopts_mac != wolopts;
                if (wolopts & WAKE_MAGICSECURE)
                        changed |= !!memcmp(wol->sopass, pl->wol_sopass,
                                            sizeof(wol->sopass));
                memcpy(pl->wol_sopass, wol->sopass, sizeof(pl->wol_sopass));

                if (changed) {
                        ret = pl->mac_ops->mac_wol_set(pl->config, wolopts,
                                                       wol->sopass);
                        if (!ret)
                                pl->wolopts_mac = wolopts;
                } else {
                        ret = 0;
                }
        } else {
                if (pl->phydev)
                        ret = phy_ethtool_set_wol(pl->phydev, wol);
        }

        return ret;
}
EXPORT_SYMBOL_GPL(phylink_ethtool_set_wol);

static phy_interface_t phylink_sfp_select_interface(struct phylink *pl,
                                                const unsigned long *link_modes)
{
        phy_interface_t interface;

        interface = sfp_select_interface(pl->sfp_bus, link_modes);
        if (interface == PHY_INTERFACE_MODE_NA) {
                phylink_err(pl,
                            "selection of interface failed, advertisement %*pb\n",
                            __ETHTOOL_LINK_MODE_MASK_NBITS,
                            link_modes);
                return interface;
        }

        if (!test_bit(interface, pl->config->supported_interfaces)) {
                phylink_err(pl,
                            "selection of interface failed, SFP selected %s (%u) but MAC supports %*pbl\n",
                            phy_modes(interface), interface,
                            (int)PHY_INTERFACE_MODE_MAX,
                            pl->config->supported_interfaces);
                return PHY_INTERFACE_MODE_NA;
        }

        return interface;
}

static phy_interface_t phylink_sfp_select_interface_speed(struct phylink *pl,
                                                          u32 speed)
{
        phy_interface_t best_interface = PHY_INTERFACE_MODE_NA;
        phy_interface_t interface;
        u32 max_speed;
        int i;

        for (i = 0; i < ARRAY_SIZE(phylink_sfp_interface_preference); i++) {
                interface = phylink_sfp_interface_preference[i];
                if (!test_bit(interface, pl->sfp_interfaces))
                        continue;

                max_speed = phylink_interface_max_speed(interface);

                /* The logic here is: if speed == max_speed, then we've found
                 * the best interface. Otherwise we find the interface that
                 * can just support the requested speed.
                 */
                if (max_speed >= speed)
                        best_interface = interface;

                if (max_speed <= speed)
                        break;
        }

        if (best_interface == PHY_INTERFACE_MODE_NA)
                phylink_err(pl, "selection of interface failed, speed %u\n",
                            speed);

        return best_interface;
}

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);
        if (kset->base.rate_matching == RATE_MATCH_NONE) {
                kset->base.speed = state->speed;
                kset->base.duplex = state->duplex;
        }
        kset->base.autoneg = linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                               state->advertising) ?
                                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->act_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);

static bool phylink_validate_pcs_inband_autoneg(struct phylink *pl,
                                                phy_interface_t interface,
                                                unsigned long *adv)
{
        unsigned int inband = phylink_inband_caps(pl, interface);
        unsigned int mask;

        /* If the PCS doesn't implement inband support, be permissive. */
        if (!inband)
                return true;

        if (linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, adv))
                mask = LINK_INBAND_ENABLE;
        else
                mask = LINK_INBAND_DISABLE;

        /* Check whether the PCS implements the required mode */
        return !!(inband & mask);
}

/**
 * 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);
        const struct link_capabilities *c;
        struct phylink_link_state config;

        ASSERT_RTNL();

        if (pl->phydev) {
                struct ethtool_link_ksettings phy_kset = *kset;

                linkmode_and(phy_kset.link_modes.advertising,
                             phy_kset.link_modes.advertising,
                             pl->supported);

                /* 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, &phy_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.
                 */
                c = phy_caps_lookup(kset->base.speed, kset->base.duplex,
                                    pl->supported, false);
                if (!c)
                        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->req_link_an_mode == MLO_AN_FIXED) {
                        if (c->speed != pl->link_config.speed ||
                            c->duplex != pl->link_config.duplex)
                                return -EINVAL;
                        return 0;
                }

                config.speed = c->speed;
                config.duplex = c->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->req_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.
         */
        linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, config.advertising,
                         kset->base.autoneg == AUTONEG_ENABLE);

        /* 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) {
                if (kset->base.autoneg == AUTONEG_ENABLE)
                        config.interface =
                                phylink_sfp_select_interface(pl,
                                                        config.advertising);
                else
                        config.interface =
                                phylink_sfp_select_interface_speed(pl,
                                                        config.speed);
                if (config.interface == PHY_INTERFACE_MODE_NA)
                        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->req_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 (linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                              config.advertising) &&
            phylink_is_empty_linkmode(config.advertising))
                return -EINVAL;

        /* Validate the autonegotiation state. We don't have a PHY in this
         * situation, so the PCS is the media-facing entity.
         */
        if (!phylink_validate_pcs_inband_autoneg(pl, config.interface,
                                                 config.advertising))
                return -EINVAL;

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

        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_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->req_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->link_failed = 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_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_keee for the read parameters
 */
int phylink_ethtool_get_eee(struct phylink *pl, struct ethtool_keee *eee)
{
        int ret = -EOPNOTSUPP;

        ASSERT_RTNL();

        if (pl->mac_supports_eee_ops && !pl->mac_supports_eee)
                return ret;

        if (pl->phydev) {
                ret = phy_ethtool_get_eee(pl->phydev, eee);
                /* Restrict supported linkmode mask */
                if (ret == 0 && pl->mac_supports_eee_ops)
                        linkmode_and(eee->supported, eee->supported,
                                     pl->supported_lpi);
        }

        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_keee for the desired parameters
 */
int phylink_ethtool_set_eee(struct phylink *pl, struct ethtool_keee *eee)
{
        bool mac_eee = pl->mac_supports_eee;
        int ret = -EOPNOTSUPP;

        ASSERT_RTNL();

        phylink_dbg(pl, "mac %s phylink EEE%s, adv %*pbl, LPI%s timer %uus\n",
                    mac_eee ? "supports" : "does not support",
                    eee->eee_enabled ? ", enabled" : "",
                    __ETHTOOL_LINK_MODE_MASK_NBITS, eee->advertised,
                    eee->tx_lpi_enabled ? " enabled" : "", eee->tx_lpi_timer);

        if (pl->mac_supports_eee_ops && !mac_eee)
                return ret;

        if (pl->phydev) {
                /* Restrict advertisement mask */
                if (pl->mac_supports_eee_ops)
                        linkmode_and(eee->advertised, eee->advertised,
                                     pl->supported_lpi);
                ret = phy_ethtool_set_eee(pl->phydev, eee);
                if (ret == 0)
                        eee_to_eeecfg(&pl->eee_cfg, 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);
                return mdiobus_c45_read(pl->phydev->mdio.bus, prtad, devad,
                                        reg);
        }

        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;
                return mdiobus_c45_read(pl->phydev->mdio.bus, prtad, devad,
                                        reg);
        }

        return mdiobus_read(pl->phydev->mdio.bus, phy_id, reg);
}

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);
                return mdiobus_c45_write(pl->phydev->mdio.bus, prtad, devad,
                                         reg, val);
        }

        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;
                }
                return mdiobus_c45_write(pl->phydev->mdio.bus, phy_id, devad,
                                         reg, val);
        }

        return mdiobus_write(phydev->mdio.bus, phy_id, reg, 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->act_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->act_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 phy_interface_t phylink_choose_sfp_interface(struct phylink *pl,
                                                    const unsigned long *intf)
{
        phy_interface_t interface;
        size_t i;

        interface = PHY_INTERFACE_MODE_NA;
        for (i = 0; i < ARRAY_SIZE(phylink_sfp_interface_preference); i++)
                if (test_bit(phylink_sfp_interface_preference[i], intf)) {
                        interface = phylink_sfp_interface_preference[i];
                        break;
                }

        return interface;
}

static void phylink_sfp_set_config(struct phylink *pl, unsigned long *supported,
                                   struct phylink_link_state *state,
                                   bool changed)
{
        u8 mode = MLO_AN_INBAND;

        phylink_dbg(pl, "requesting link mode %s/%s with support %*pb\n",
                    phylink_an_mode_str(mode), phy_modes(state->interface),
                    __ETHTOOL_LINK_MODE_MASK_NBITS, supported);

        if (!linkmode_equal(pl->supported, supported)) {
                linkmode_copy(pl->supported, supported);
                changed = true;
        }

        if (!linkmode_equal(pl->link_config.advertising, state->advertising)) {
                linkmode_copy(pl->link_config.advertising, state->advertising);
                changed = true;
        }

        if (pl->req_link_an_mode != mode ||
            pl->link_config.interface != state->interface) {
                pl->req_link_an_mode = mode;
                pl->link_config.interface = state->interface;

                changed = true;

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

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

static int phylink_sfp_config_phy(struct phylink *pl, struct phy_device *phy)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(support);
        struct phylink_link_state config;
        int ret;

        /* We're not using pl->sfp_interfaces, so clear it. */
        phy_interface_zero(pl->sfp_interfaces);
        linkmode_copy(support, phy->supported);

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

        /* 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: %pe\n",
                            __ETHTOOL_LINK_MODE_MASK_NBITS, support,
                            ERR_PTR(ret));
                return ret;
        }

        config.interface = phylink_sfp_select_interface(pl, config.advertising);
        if (config.interface == PHY_INTERFACE_MODE_NA)
                return -EINVAL;

        /* Attach the PHY so that the PHY is present when we do the major
         * configuration step.
         */
        ret = phylink_attach_phy(pl, phy, config.interface);
        if (ret < 0)
                return ret;

        /* This will validate the configuration for us. */
        ret = phylink_bringup_phy(pl, phy, config.interface);
        if (ret < 0) {
                phy_detach(phy);
                return ret;
        }

        pl->link_port = pl->sfp_port;

        phylink_sfp_set_config(pl, support, &config, true);

        return 0;
}

static int phylink_sfp_config_optical(struct phylink *pl)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(support);
        struct phylink_link_state config;
        enum inband_type inband_type;
        phy_interface_t interface;
        int ret;

        phylink_dbg(pl, "optical SFP: interfaces=[mac=%*pbl, sfp=%*pbl]\n",
                    (int)PHY_INTERFACE_MODE_MAX,
                    pl->config->supported_interfaces,
                    (int)PHY_INTERFACE_MODE_MAX,
                    pl->sfp_interfaces);

        /* Find the union of the supported interfaces by the PCS/MAC and
         * the SFP module.
         */
        phy_interface_and(pl->sfp_interfaces, pl->config->supported_interfaces,
                          pl->sfp_interfaces);
        if (phy_interface_empty(pl->sfp_interfaces)) {
                phylink_err(pl, "unsupported SFP module: no common interface modes\n");
                return -EINVAL;
        }

        memset(&config, 0, sizeof(config));
        linkmode_copy(support, pl->sfp_support);
        linkmode_copy(config.advertising, pl->sfp_support);
        config.speed = SPEED_UNKNOWN;
        config.duplex = DUPLEX_UNKNOWN;
        config.pause = MLO_PAUSE_AN;

        /* For all the interfaces that are supported, reduce the sfp_support
         * mask to only those link modes that can be supported.
         */
        ret = phylink_validate_mask(pl, NULL, pl->sfp_support, &config,
                                    pl->sfp_interfaces);
        if (ret) {
                phylink_err(pl, "unsupported SFP module: validation with support %*pb failed\n",
                            __ETHTOOL_LINK_MODE_MASK_NBITS, support);
                return ret;
        }

        interface = phylink_choose_sfp_interface(pl, pl->sfp_interfaces);
        if (interface == PHY_INTERFACE_MODE_NA) {
                phylink_err(pl, "failed to select SFP interface\n");
                return -EINVAL;
        }

        phylink_dbg(pl, "optical SFP: chosen %s interface\n",
                    phy_modes(interface));

        inband_type = phylink_get_inband_type(interface);
        if (inband_type == INBAND_NONE) {
                /* If this is the sole interface, and there is no inband
                 * support, clear the advertising mask and Autoneg bit in
                 * the support mask. Otherwise, just clear the Autoneg bit
                 * in the advertising mask.
                 */
                if (phy_interface_weight(pl->sfp_interfaces) == 1) {
                        linkmode_clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                           pl->sfp_support);
                        linkmode_zero(config.advertising);
                } else {
                        linkmode_clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
                                           config.advertising);
                }
        }

        if (!phylink_validate_pcs_inband_autoneg(pl, interface,
                                                 config.advertising)) {
                phylink_err(pl, "autoneg setting not compatible with PCS");
                return -EINVAL;
        }

        config.interface = interface;

        /* 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: %pe\n",
                            __ETHTOOL_LINK_MODE_MASK_NBITS, support,
                            ERR_PTR(ret));
                return ret;
        }

        pl->link_port = pl->sfp_port;

        phylink_sfp_set_config(pl, pl->sfp_support, &config, false);

        return 0;
}

static int phylink_sfp_module_insert(void *upstream,
                                     const struct sfp_eeprom_id *id)
{
        const struct sfp_module_caps *caps;
        struct phylink *pl = upstream;

        ASSERT_RTNL();

        caps = sfp_get_module_caps(pl->sfp_bus);
        phy_interface_copy(pl->sfp_interfaces, caps->interfaces);
        linkmode_copy(pl->sfp_support, caps->link_modes);
        pl->sfp_may_have_phy = caps->may_have_phy;
        pl->sfp_port = caps->port;

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

        return phylink_sfp_config_optical(pl);
}

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

        phy_interface_zero(pl->sfp_interfaces);
}

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_optical(pl);
}

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();

        phylink_enable_and_run_resolve(pl, PHYLINK_DISABLE_LINK);
}

static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
{
        struct phylink *pl = upstream;

        if (!phy->drv) {
                phylink_err(pl, "PHY %s (id 0x%.8lx) has no driver loaded\n",
                            phydev_name(phy), (unsigned long)phy->phy_id);
                phylink_err(pl, "Drivers which handle known common cases: CONFIG_BCM84881_PHY, CONFIG_MARVELL_PHY\n");
                return -EINVAL;
        }

        /*
         * 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);

        /* Set the PHY's host supported interfaces */
        phy_interface_and(phy->host_interfaces, phylink_sfp_interfaces,
                          pl->config->supported_interfaces);

        /* Do the initial configuration */
        return phylink_sfp_config_phy(pl, phy);
}

static void phylink_sfp_disconnect_phy(void *upstream,
                                       struct phy_device *phydev)
{
        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_remove = phylink_sfp_module_remove,
        .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 */

static struct {
        int bit;
        int speed;
} phylink_c73_priority_resolution[] = {
        { ETHTOOL_LINK_MODE_100000baseCR4_Full_BIT, SPEED_100000 },
        { ETHTOOL_LINK_MODE_100000baseKR4_Full_BIT, SPEED_100000 },
        /* 100GBASE-KP4 and 100GBASE-CR10 not supported */
        { ETHTOOL_LINK_MODE_40000baseCR4_Full_BIT, SPEED_40000 },
        { ETHTOOL_LINK_MODE_40000baseKR4_Full_BIT, SPEED_40000 },
        { ETHTOOL_LINK_MODE_10000baseKR_Full_BIT, SPEED_10000 },
        { ETHTOOL_LINK_MODE_10000baseKX4_Full_BIT, SPEED_10000 },
        /* 5GBASE-KR not supported */
        { ETHTOOL_LINK_MODE_2500baseX_Full_BIT, SPEED_2500 },
        { ETHTOOL_LINK_MODE_1000baseKX_Full_BIT, SPEED_1000 },
};

void phylink_resolve_c73(struct phylink_link_state *state)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(phylink_c73_priority_resolution); i++) {
                int bit = phylink_c73_priority_resolution[i].bit;
                if (linkmode_test_bit(bit, state->advertising) &&
                    linkmode_test_bit(bit, state->lp_advertising))
                        break;
        }

        if (i < ARRAY_SIZE(phylink_c73_priority_resolution)) {
                state->speed = phylink_c73_priority_resolution[i].speed;
                state->duplex = DUPLEX_FULL;
        } else {
                /* negotiation failure */
                state->link = false;
        }

        phylink_resolve_an_pause(state);
}
EXPORT_SYMBOL_GPL(phylink_resolve_c73);

static void phylink_decode_c37_word(struct phylink_link_state *state,
                                    uint16_t config_reg, int speed)
{
        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;
        }

        phylink_resolve_an_pause(state);
}

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_decode_usgmii_word() - decode the USGMII word from a MAC PCS
 * @state: a pointer to a struct phylink_link_state.
 * @lpa: a 16 bit value which stores the USGMII auto-negotiation word
 *
 * Helper for MAC PCS supporting the USGMII protocol and the auto-negotiation
 * code word.  Decode the USGMII code word and populate the corresponding fields
 * (speed, duplex) into the phylink_link_state structure. The structure for this
 * word is the same as the USXGMII word, except it only supports speeds up to
 * 1Gbps.
 */
static void phylink_decode_usgmii_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;
        default:
                state->link = false;
                return;
        }

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

/**
 * phylink_mii_c22_pcs_decode_state() - Decode MAC PCS state from MII registers
 * @state: a pointer to a &struct phylink_link_state.
 * @neg_mode: link negotiation mode (PHYLINK_PCS_NEG_xxx)
 * @bmsr: The value of the %MII_BMSR register
 * @lpa: The value of the %MII_LPA register
 *
 * Helper for MAC PCS supporting the 802.3 clause 22 register set for
 * clause 37 negotiation and/or SGMII control.
 *
 * Parse the Clause 37 or Cisco SGMII link partner negotiation word into
 * the phylink @state structure. This is suitable to be used for implementing
 * the pcs_get_state() member of the struct phylink_pcs_ops structure if
 * accessing @bmsr and @lpa cannot be done with MDIO directly.
 */
void phylink_mii_c22_pcs_decode_state(struct phylink_link_state *state,
                                      unsigned int neg_mode, u16 bmsr, u16 lpa)
{
        state->link = !!(bmsr & BMSR_LSTATUS);
        state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);

        /* If the link is down, the advertisement data is undefined. */
        if (!state->link)
                return;

        switch (state->interface) {
        case PHY_INTERFACE_MODE_1000BASEX:
                if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) {
                        phylink_decode_c37_word(state, lpa, SPEED_1000);
                } else {
                        state->speed = SPEED_1000;
                        state->duplex = DUPLEX_FULL;
                        state->pause |= MLO_PAUSE_TX | MLO_PAUSE_RX;
                }
                break;

        case PHY_INTERFACE_MODE_2500BASEX:
                if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) {
                        phylink_decode_c37_word(state, lpa, SPEED_2500);
                } else {
                        state->speed = SPEED_2500;
                        state->duplex = DUPLEX_FULL;
                        state->pause |= MLO_PAUSE_TX | MLO_PAUSE_RX;
                }
                break;

        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_QSGMII:
                if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
                        phylink_decode_sgmii_word(state, lpa);
                break;

        case PHY_INTERFACE_MODE_QUSGMII:
                if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
                        phylink_decode_usgmii_word(state, lpa);
                break;

        default:
                state->link = false;
                break;
        }
}
EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_decode_state);

/**
 * phylink_mii_c22_pcs_get_state() - read the MAC PCS state
 * @pcs: a pointer to a &struct mdio_device.
 * @neg_mode: link negotiation mode (PHYLINK_PCS_NEG_xxx)
 * @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 pcs_get_state() member of the struct phylink_pcs_ops
 * structure.
 */
void phylink_mii_c22_pcs_get_state(struct mdio_device *pcs,
                                   unsigned int neg_mode,
                                   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;
        }

        phylink_mii_c22_pcs_decode_state(state, neg_mode, bmsr, lpa);
}
EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_get_state);

/**
 * phylink_mii_c22_pcs_encode_advertisement() - configure the clause 37 PCS
 *      advertisement
 * @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.
 *
 * Encode the clause 37 PCS advertisement as specified by @interface and
 * @advertising.
 *
 * Return: The new value for @adv, or ``-EINVAL`` if it should not be changed.
 */
int phylink_mii_c22_pcs_encode_advertisement(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 adv;
        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_QSGMII:
                return 0x0001;
        default:
                /* Nothing to do for other modes */
                return -EINVAL;
        }
}
EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_encode_advertisement);

/**
 * phylink_mii_c22_pcs_config() - configure clause 22 PCS
 * @pcs: a pointer to a &struct mdio_device.
 * @interface: the PHY interface mode being configured
 * @advertising: the ethtool advertisement mask
 * @neg_mode: PCS negotiation mode
 *
 * 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,
                               phy_interface_t interface,
                               const unsigned long *advertising,
                               unsigned int neg_mode)
{
        bool changed = 0;
        u16 bmcr;
        int ret, adv;

        adv = phylink_mii_c22_pcs_encode_advertisement(interface, advertising);
        if (adv >= 0) {
                ret = mdiobus_modify_changed(pcs->bus, pcs->addr,
                                             MII_ADVERTISE, 0xffff, adv);
                if (ret < 0)
                        return ret;
                changed = ret;
        }

        if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
                bmcr = BMCR_ANENABLE;
        else
                bmcr = 0;

        /* Configure the inband state. Ensure ISOLATE bit is disabled */
        ret = mdiodev_modify(pcs, MII_BMCR, BMCR_ANENABLE | BMCR_ISOLATE, bmcr);
        if (ret < 0)
                return ret;

        return changed;
}
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 pcs_get_state() member
 * of the struct phylink_pcs_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);

/**
 * phylink_replay_link_begin() - begin replay of link callbacks for driver
 *                               which loses state
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Helper for MAC drivers which may perform a destructive reset at runtime.
 * Both the own driver's mac_link_down() method is called, as well as the
 * pcs_link_down() method of the split PCS (if any).
 *
 * This is similar to phylink_stop(), except it does not alter the state of
 * the phylib PHY (it is assumed that it is not affected by the MAC destructive
 * reset).
 */
void phylink_replay_link_begin(struct phylink *pl)
{
        ASSERT_RTNL();

        phylink_run_resolve_and_disable(pl, PHYLINK_DISABLE_REPLAY);
}
EXPORT_SYMBOL_GPL(phylink_replay_link_begin);

/**
 * phylink_replay_link_end() - end replay of link callbacks for driver
 *                             which lost state
 * @pl: a pointer to a &struct phylink returned from phylink_create()
 *
 * Helper for MAC drivers which may perform a destructive reset at runtime.
 * Both the own driver's mac_config() and mac_link_up() methods, as well as the
 * pcs_config() and pcs_link_up() method of the split PCS (if any), are called.
 *
 * This is similar to phylink_start(), except it does not alter the state of
 * the phylib PHY.
 *
 * One must call this method only within the same rtnl_lock() critical section
 * as a previous phylink_replay_link_start().
 */
void phylink_replay_link_end(struct phylink *pl)
{
        ASSERT_RTNL();

        if (WARN(!test_bit(PHYLINK_DISABLE_REPLAY,
                           &pl->phylink_disable_state),
                 "phylink_replay_link_end() called without a prior phylink_replay_link_begin()\n"))
                return;

        pl->force_major_config = true;
        phylink_enable_and_run_resolve(pl, PHYLINK_DISABLE_REPLAY);
        flush_work(&pl->resolve);
}
EXPORT_SYMBOL_GPL(phylink_replay_link_end);

static int __init phylink_init(void)
{
        for (int i = 0; i < ARRAY_SIZE(phylink_sfp_interface_preference); ++i)
                __set_bit(phylink_sfp_interface_preference[i],
                          phylink_sfp_interfaces);

        return 0;
}

module_init(phylink_init);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("phylink models the MAC to optional PHY connection");