GNU Linux-libre 4.9.330-gnu1

[releases.git] / drivers / net / ethernet / intel / e1000e / mac.c

/* Intel PRO/1000 Linux driver
 * Copyright(c) 1999 - 2015 Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * The full GNU General Public License is included in this distribution in
 * the file called "COPYING".
 *
 * Contact Information:
 * Linux NICS <linux.nics@intel.com>
 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 */

#include "e1000.h"

/**
 *  e1000e_get_bus_info_pcie - Get PCIe bus information
 *  @hw: pointer to the HW structure
 *
 *  Determines and stores the system bus information for a particular
 *  network interface.  The following bus information is determined and stored:
 *  bus speed, bus width, type (PCIe), and PCIe function.
 **/
s32 e1000e_get_bus_info_pcie(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;
        struct e1000_bus_info *bus = &hw->bus;
        struct e1000_adapter *adapter = hw->adapter;
        u16 pcie_link_status, cap_offset;

        cap_offset = adapter->pdev->pcie_cap;
        if (!cap_offset) {
                bus->width = e1000_bus_width_unknown;
        } else {
                pci_read_config_word(adapter->pdev,
                                     cap_offset + PCIE_LINK_STATUS,
                                     &pcie_link_status);
                bus->width = (enum e1000_bus_width)((pcie_link_status &
                                                     PCIE_LINK_WIDTH_MASK) >>
                                                    PCIE_LINK_WIDTH_SHIFT);
        }

        mac->ops.set_lan_id(hw);

        return 0;
}

/**
 *  e1000_set_lan_id_multi_port_pcie - Set LAN id for PCIe multiple port devices
 *
 *  @hw: pointer to the HW structure
 *
 *  Determines the LAN function id by reading memory-mapped registers
 *  and swaps the port value if requested.
 **/
void e1000_set_lan_id_multi_port_pcie(struct e1000_hw *hw)
{
        struct e1000_bus_info *bus = &hw->bus;
        u32 reg;

        /* The status register reports the correct function number
         * for the device regardless of function swap state.
         */
        reg = er32(STATUS);
        bus->func = (reg & E1000_STATUS_FUNC_MASK) >> E1000_STATUS_FUNC_SHIFT;
}

/**
 *  e1000_set_lan_id_single_port - Set LAN id for a single port device
 *  @hw: pointer to the HW structure
 *
 *  Sets the LAN function id to zero for a single port device.
 **/
void e1000_set_lan_id_single_port(struct e1000_hw *hw)
{
        struct e1000_bus_info *bus = &hw->bus;

        bus->func = 0;
}

/**
 *  e1000_clear_vfta_generic - Clear VLAN filter table
 *  @hw: pointer to the HW structure
 *
 *  Clears the register array which contains the VLAN filter table by
 *  setting all the values to 0.
 **/
void e1000_clear_vfta_generic(struct e1000_hw *hw)
{
        u32 offset;

        for (offset = 0; offset < E1000_VLAN_FILTER_TBL_SIZE; offset++) {
                E1000_WRITE_REG_ARRAY(hw, E1000_VFTA, offset, 0);
                e1e_flush();
        }
}

/**
 *  e1000_write_vfta_generic - Write value to VLAN filter table
 *  @hw: pointer to the HW structure
 *  @offset: register offset in VLAN filter table
 *  @value: register value written to VLAN filter table
 *
 *  Writes value at the given offset in the register array which stores
 *  the VLAN filter table.
 **/
void e1000_write_vfta_generic(struct e1000_hw *hw, u32 offset, u32 value)
{
        E1000_WRITE_REG_ARRAY(hw, E1000_VFTA, offset, value);
        e1e_flush();
}

/**
 *  e1000e_init_rx_addrs - Initialize receive address's
 *  @hw: pointer to the HW structure
 *  @rar_count: receive address registers
 *
 *  Setup the receive address registers by setting the base receive address
 *  register to the devices MAC address and clearing all the other receive
 *  address registers to 0.
 **/
void e1000e_init_rx_addrs(struct e1000_hw *hw, u16 rar_count)
{
        u32 i;
        u8 mac_addr[ETH_ALEN] = { 0 };

        /* Setup the receive address */
        e_dbg("Programming MAC Address into RAR[0]\n");

        hw->mac.ops.rar_set(hw, hw->mac.addr, 0);

        /* Zero out the other (rar_entry_count - 1) receive addresses */
        e_dbg("Clearing RAR[1-%u]\n", rar_count - 1);
        for (i = 1; i < rar_count; i++)
                hw->mac.ops.rar_set(hw, mac_addr, i);
}

/**
 *  e1000_check_alt_mac_addr_generic - Check for alternate MAC addr
 *  @hw: pointer to the HW structure
 *
 *  Checks the nvm for an alternate MAC address.  An alternate MAC address
 *  can be setup by pre-boot software and must be treated like a permanent
 *  address and must override the actual permanent MAC address. If an
 *  alternate MAC address is found it is programmed into RAR0, replacing
 *  the permanent address that was installed into RAR0 by the Si on reset.
 *  This function will return SUCCESS unless it encounters an error while
 *  reading the EEPROM.
 **/
s32 e1000_check_alt_mac_addr_generic(struct e1000_hw *hw)
{
        u32 i;
        s32 ret_val;
        u16 offset, nvm_alt_mac_addr_offset, nvm_data;
        u8 alt_mac_addr[ETH_ALEN];

        ret_val = e1000_read_nvm(hw, NVM_COMPAT, 1, &nvm_data);
        if (ret_val)
                return ret_val;

        /* not supported on 82573 */
        if (hw->mac.type == e1000_82573)
                return 0;

        ret_val = e1000_read_nvm(hw, NVM_ALT_MAC_ADDR_PTR, 1,
                                 &nvm_alt_mac_addr_offset);
        if (ret_val) {
                e_dbg("NVM Read Error\n");
                return ret_val;
        }

        if ((nvm_alt_mac_addr_offset == 0xFFFF) ||
            (nvm_alt_mac_addr_offset == 0x0000))
                /* There is no Alternate MAC Address */
                return 0;

        if (hw->bus.func == E1000_FUNC_1)
                nvm_alt_mac_addr_offset += E1000_ALT_MAC_ADDRESS_OFFSET_LAN1;
        for (i = 0; i < ETH_ALEN; i += 2) {
                offset = nvm_alt_mac_addr_offset + (i >> 1);
                ret_val = e1000_read_nvm(hw, offset, 1, &nvm_data);
                if (ret_val) {
                        e_dbg("NVM Read Error\n");
                        return ret_val;
                }

                alt_mac_addr[i] = (u8)(nvm_data & 0xFF);
                alt_mac_addr[i + 1] = (u8)(nvm_data >> 8);
        }

        /* if multicast bit is set, the alternate address will not be used */
        if (is_multicast_ether_addr(alt_mac_addr)) {
                e_dbg("Ignoring Alternate Mac Address with MC bit set\n");
                return 0;
        }

        /* We have a valid alternate MAC address, and we want to treat it the
         * same as the normal permanent MAC address stored by the HW into the
         * RAR. Do this by mapping this address into RAR0.
         */
        hw->mac.ops.rar_set(hw, alt_mac_addr, 0);

        return 0;
}

u32 e1000e_rar_get_count_generic(struct e1000_hw *hw)
{
        return hw->mac.rar_entry_count;
}

/**
 *  e1000e_rar_set_generic - Set receive address register
 *  @hw: pointer to the HW structure
 *  @addr: pointer to the receive address
 *  @index: receive address array register
 *
 *  Sets the receive address array register at index to the address passed
 *  in by addr.
 **/
int e1000e_rar_set_generic(struct e1000_hw *hw, u8 *addr, u32 index)
{
        u32 rar_low, rar_high;

        /* HW expects these in little endian so we reverse the byte order
         * from network order (big endian) to little endian
         */
        rar_low = ((u32)addr[0] | ((u32)addr[1] << 8) |
                   ((u32)addr[2] << 16) | ((u32)addr[3] << 24));

        rar_high = ((u32)addr[4] | ((u32)addr[5] << 8));

        /* If MAC address zero, no need to set the AV bit */
        if (rar_low || rar_high)
                rar_high |= E1000_RAH_AV;

        /* Some bridges will combine consecutive 32-bit writes into
         * a single burst write, which will malfunction on some parts.
         * The flushes avoid this.
         */
        ew32(RAL(index), rar_low);
        e1e_flush();
        ew32(RAH(index), rar_high);
        e1e_flush();

        return 0;
}

/**
 *  e1000_hash_mc_addr - Generate a multicast hash value
 *  @hw: pointer to the HW structure
 *  @mc_addr: pointer to a multicast address
 *
 *  Generates a multicast address hash value which is used to determine
 *  the multicast filter table array address and new table value.
 **/
static u32 e1000_hash_mc_addr(struct e1000_hw *hw, u8 *mc_addr)
{
        u32 hash_value, hash_mask;
        u8 bit_shift = 0;

        /* Register count multiplied by bits per register */
        hash_mask = (hw->mac.mta_reg_count * 32) - 1;

        /* For a mc_filter_type of 0, bit_shift is the number of left-shifts
         * where 0xFF would still fall within the hash mask.
         */
        while (hash_mask >> bit_shift != 0xFF)
                bit_shift++;

        /* The portion of the address that is used for the hash table
         * is determined by the mc_filter_type setting.
         * The algorithm is such that there is a total of 8 bits of shifting.
         * The bit_shift for a mc_filter_type of 0 represents the number of
         * left-shifts where the MSB of mc_addr[5] would still fall within
         * the hash_mask.  Case 0 does this exactly.  Since there are a total
         * of 8 bits of shifting, then mc_addr[4] will shift right the
         * remaining number of bits. Thus 8 - bit_shift.  The rest of the
         * cases are a variation of this algorithm...essentially raising the
         * number of bits to shift mc_addr[5] left, while still keeping the
         * 8-bit shifting total.
         *
         * For example, given the following Destination MAC Address and an
         * mta register count of 128 (thus a 4096-bit vector and 0xFFF mask),
         * we can see that the bit_shift for case 0 is 4.  These are the hash
         * values resulting from each mc_filter_type...
         * [0] [1] [2] [3] [4] [5]
         * 01  AA  00  12  34  56
         * LSB           MSB
         *
         * case 0: hash_value = ((0x34 >> 4) | (0x56 << 4)) & 0xFFF = 0x563
         * case 1: hash_value = ((0x34 >> 3) | (0x56 << 5)) & 0xFFF = 0xAC6
         * case 2: hash_value = ((0x34 >> 2) | (0x56 << 6)) & 0xFFF = 0x163
         * case 3: hash_value = ((0x34 >> 0) | (0x56 << 8)) & 0xFFF = 0x634
         */
        switch (hw->mac.mc_filter_type) {
        default:
        case 0:
                break;
        case 1:
                bit_shift += 1;
                break;
        case 2:
                bit_shift += 2;
                break;
        case 3:
                bit_shift += 4;
                break;
        }

        hash_value = hash_mask & (((mc_addr[4] >> (8 - bit_shift)) |
                                   (((u16)mc_addr[5]) << bit_shift)));

        return hash_value;
}

/**
 *  e1000e_update_mc_addr_list_generic - Update Multicast addresses
 *  @hw: pointer to the HW structure
 *  @mc_addr_list: array of multicast addresses to program
 *  @mc_addr_count: number of multicast addresses to program
 *
 *  Updates entire Multicast Table Array.
 *  The caller must have a packed mc_addr_list of multicast addresses.
 **/
void e1000e_update_mc_addr_list_generic(struct e1000_hw *hw,
                                        u8 *mc_addr_list, u32 mc_addr_count)
{
        u32 hash_value, hash_bit, hash_reg;
        int i;

        /* clear mta_shadow */
        memset(&hw->mac.mta_shadow, 0, sizeof(hw->mac.mta_shadow));

        /* update mta_shadow from mc_addr_list */
        for (i = 0; (u32)i < mc_addr_count; i++) {
                hash_value = e1000_hash_mc_addr(hw, mc_addr_list);

                hash_reg = (hash_value >> 5) & (hw->mac.mta_reg_count - 1);
                hash_bit = hash_value & 0x1F;

                hw->mac.mta_shadow[hash_reg] |= BIT(hash_bit);
                mc_addr_list += (ETH_ALEN);
        }

        /* replace the entire MTA table */
        for (i = hw->mac.mta_reg_count - 1; i >= 0; i--)
                E1000_WRITE_REG_ARRAY(hw, E1000_MTA, i, hw->mac.mta_shadow[i]);
        e1e_flush();
}

/**
 *  e1000e_clear_hw_cntrs_base - Clear base hardware counters
 *  @hw: pointer to the HW structure
 *
 *  Clears the base hardware counters by reading the counter registers.
 **/
void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw)
{
        er32(CRCERRS);
        er32(SYMERRS);
        er32(MPC);
        er32(SCC);
        er32(ECOL);
        er32(MCC);
        er32(LATECOL);
        er32(COLC);
        er32(DC);
        er32(SEC);
        er32(RLEC);
        er32(XONRXC);
        er32(XONTXC);
        er32(XOFFRXC);
        er32(XOFFTXC);
        er32(FCRUC);
        er32(GPRC);
        er32(BPRC);
        er32(MPRC);
        er32(GPTC);
        er32(GORCL);
        er32(GORCH);
        er32(GOTCL);
        er32(GOTCH);
        er32(RNBC);
        er32(RUC);
        er32(RFC);
        er32(ROC);
        er32(RJC);
        er32(TORL);
        er32(TORH);
        er32(TOTL);
        er32(TOTH);
        er32(TPR);
        er32(TPT);
        er32(MPTC);
        er32(BPTC);
}

/**
 *  e1000e_check_for_copper_link - Check for link (Copper)
 *  @hw: pointer to the HW structure
 *
 *  Checks to see of the link status of the hardware has changed.  If a
 *  change in link status has been detected, then we read the PHY registers
 *  to get the current speed/duplex if link exists.
 **/
s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;
        s32 ret_val;
        bool link;

        /* We only want to go out to the PHY registers to see if Auto-Neg
         * has completed and/or if our link status has changed.  The
         * get_link_status flag is set upon receiving a Link Status
         * Change or Rx Sequence Error interrupt.
         */
        if (!mac->get_link_status)
                return 0;
        mac->get_link_status = false;

        /* First we want to see if the MII Status Register reports
         * link.  If so, then we want to get the current speed/duplex
         * of the PHY.
         */
        ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);
        if (ret_val || !link)
                goto out;

        /* Check if there was DownShift, must be checked
         * immediately after link-up
         */
        e1000e_check_downshift(hw);

        /* If we are forcing speed/duplex, then we simply return since
         * we have already determined whether we have link or not.
         */
        if (!mac->autoneg)
                return -E1000_ERR_CONFIG;

        /* Auto-Neg is enabled.  Auto Speed Detection takes care
         * of MAC speed/duplex configuration.  So we only need to
         * configure Collision Distance in the MAC.
         */
        mac->ops.config_collision_dist(hw);

        /* Configure Flow Control now that Auto-Neg has completed.
         * First, we need to restore the desired flow control
         * settings because we may have had to re-autoneg with a
         * different link partner.
         */
        ret_val = e1000e_config_fc_after_link_up(hw);
        if (ret_val)
                e_dbg("Error configuring flow control\n");

        return ret_val;

out:
        mac->get_link_status = true;
        return ret_val;
}

/**
 *  e1000e_check_for_fiber_link - Check for link (Fiber)
 *  @hw: pointer to the HW structure
 *
 *  Checks for link up on the hardware.  If link is not up and we have
 *  a signal, then we need to force link up.
 **/
s32 e1000e_check_for_fiber_link(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;
        u32 rxcw;
        u32 ctrl;
        u32 status;
        s32 ret_val;

        ctrl = er32(CTRL);
        status = er32(STATUS);
        rxcw = er32(RXCW);

        /* If we don't have link (auto-negotiation failed or link partner
         * cannot auto-negotiate), the cable is plugged in (we have signal),
         * and our link partner is not trying to auto-negotiate with us (we
         * are receiving idles or data), we need to force link up. We also
         * need to give auto-negotiation time to complete, in case the cable
         * was just plugged in. The autoneg_failed flag does this.
         */
        /* (ctrl & E1000_CTRL_SWDPIN1) == 1 == have signal */
        if ((ctrl & E1000_CTRL_SWDPIN1) && !(status & E1000_STATUS_LU) &&
            !(rxcw & E1000_RXCW_C)) {
                if (!mac->autoneg_failed) {
                        mac->autoneg_failed = true;
                        return 0;
                }
                e_dbg("NOT Rx'ing /C/, disable AutoNeg and force link.\n");

                /* Disable auto-negotiation in the TXCW register */
                ew32(TXCW, (mac->txcw & ~E1000_TXCW_ANE));

                /* Force link-up and also force full-duplex. */
                ctrl = er32(CTRL);
                ctrl |= (E1000_CTRL_SLU | E1000_CTRL_FD);
                ew32(CTRL, ctrl);

                /* Configure Flow Control after forcing link up. */
                ret_val = e1000e_config_fc_after_link_up(hw);
                if (ret_val) {
                        e_dbg("Error configuring flow control\n");
                        return ret_val;
                }
        } else if ((ctrl & E1000_CTRL_SLU) && (rxcw & E1000_RXCW_C)) {
                /* If we are forcing link and we are receiving /C/ ordered
                 * sets, re-enable auto-negotiation in the TXCW register
                 * and disable forced link in the Device Control register
                 * in an attempt to auto-negotiate with our link partner.
                 */
                e_dbg("Rx'ing /C/, enable AutoNeg and stop forcing link.\n");
                ew32(TXCW, mac->txcw);
                ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));

                mac->serdes_has_link = true;
        }

        return 0;
}

/**
 *  e1000e_check_for_serdes_link - Check for link (Serdes)
 *  @hw: pointer to the HW structure
 *
 *  Checks for link up on the hardware.  If link is not up and we have
 *  a signal, then we need to force link up.
 **/
s32 e1000e_check_for_serdes_link(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;
        u32 rxcw;
        u32 ctrl;
        u32 status;
        s32 ret_val;

        ctrl = er32(CTRL);
        status = er32(STATUS);
        rxcw = er32(RXCW);

        /* If we don't have link (auto-negotiation failed or link partner
         * cannot auto-negotiate), and our link partner is not trying to
         * auto-negotiate with us (we are receiving idles or data),
         * we need to force link up. We also need to give auto-negotiation
         * time to complete.
         */
        /* (ctrl & E1000_CTRL_SWDPIN1) == 1 == have signal */
        if (!(status & E1000_STATUS_LU) && !(rxcw & E1000_RXCW_C)) {
                if (!mac->autoneg_failed) {
                        mac->autoneg_failed = true;
                        return 0;
                }
                e_dbg("NOT Rx'ing /C/, disable AutoNeg and force link.\n");

                /* Disable auto-negotiation in the TXCW register */
                ew32(TXCW, (mac->txcw & ~E1000_TXCW_ANE));

                /* Force link-up and also force full-duplex. */
                ctrl = er32(CTRL);
                ctrl |= (E1000_CTRL_SLU | E1000_CTRL_FD);
                ew32(CTRL, ctrl);

                /* Configure Flow Control after forcing link up. */
                ret_val = e1000e_config_fc_after_link_up(hw);
                if (ret_val) {
                        e_dbg("Error configuring flow control\n");
                        return ret_val;
                }
        } else if ((ctrl & E1000_CTRL_SLU) && (rxcw & E1000_RXCW_C)) {
                /* If we are forcing link and we are receiving /C/ ordered
                 * sets, re-enable auto-negotiation in the TXCW register
                 * and disable forced link in the Device Control register
                 * in an attempt to auto-negotiate with our link partner.
                 */
                e_dbg("Rx'ing /C/, enable AutoNeg and stop forcing link.\n");
                ew32(TXCW, mac->txcw);
                ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));

                mac->serdes_has_link = true;
        } else if (!(E1000_TXCW_ANE & er32(TXCW))) {
                /* If we force link for non-auto-negotiation switch, check
                 * link status based on MAC synchronization for internal
                 * serdes media type.
                 */
                /* SYNCH bit and IV bit are sticky. */
                usleep_range(10, 20);
                rxcw = er32(RXCW);
                if (rxcw & E1000_RXCW_SYNCH) {
                        if (!(rxcw & E1000_RXCW_IV)) {
                                mac->serdes_has_link = true;
                                e_dbg("SERDES: Link up - forced.\n");
                        }
                } else {
                        mac->serdes_has_link = false;
                        e_dbg("SERDES: Link down - force failed.\n");
                }
        }

        if (E1000_TXCW_ANE & er32(TXCW)) {
                status = er32(STATUS);
                if (status & E1000_STATUS_LU) {
                        /* SYNCH bit and IV bit are sticky, so reread rxcw. */
                        usleep_range(10, 20);
                        rxcw = er32(RXCW);
                        if (rxcw & E1000_RXCW_SYNCH) {
                                if (!(rxcw & E1000_RXCW_IV)) {
                                        mac->serdes_has_link = true;
                                        e_dbg("SERDES: Link up - autoneg completed successfully.\n");
                                } else {
                                        mac->serdes_has_link = false;
                                        e_dbg("SERDES: Link down - invalid codewords detected in autoneg.\n");
                                }
                        } else {
                                mac->serdes_has_link = false;
                                e_dbg("SERDES: Link down - no sync.\n");
                        }
                } else {
                        mac->serdes_has_link = false;
                        e_dbg("SERDES: Link down - autoneg failed\n");
                }
        }

        return 0;
}

/**
 *  e1000_set_default_fc_generic - Set flow control default values
 *  @hw: pointer to the HW structure
 *
 *  Read the EEPROM for the default values for flow control and store the
 *  values.
 **/
static s32 e1000_set_default_fc_generic(struct e1000_hw *hw)
{
        s32 ret_val;
        u16 nvm_data;

        /* Read and store word 0x0F of the EEPROM. This word contains bits
         * that determine the hardware's default PAUSE (flow control) mode,
         * a bit that determines whether the HW defaults to enabling or
         * disabling auto-negotiation, and the direction of the
         * SW defined pins. If there is no SW over-ride of the flow
         * control setting, then the variable hw->fc will
         * be initialized based on a value in the EEPROM.
         */
        ret_val = e1000_read_nvm(hw, NVM_INIT_CONTROL2_REG, 1, &nvm_data);

        if (ret_val) {
                e_dbg("NVM Read Error\n");
                return ret_val;
        }

        if (!(nvm_data & NVM_WORD0F_PAUSE_MASK))
                hw->fc.requested_mode = e1000_fc_none;
        else if ((nvm_data & NVM_WORD0F_PAUSE_MASK) == NVM_WORD0F_ASM_DIR)
                hw->fc.requested_mode = e1000_fc_tx_pause;
        else
                hw->fc.requested_mode = e1000_fc_full;

        return 0;
}

/**
 *  e1000e_setup_link_generic - Setup flow control and link settings
 *  @hw: pointer to the HW structure
 *
 *  Determines which flow control settings to use, then configures flow
 *  control.  Calls the appropriate media-specific link configuration
 *  function.  Assuming the adapter has a valid link partner, a valid link
 *  should be established.  Assumes the hardware has previously been reset
 *  and the transmitter and receiver are not enabled.
 **/
s32 e1000e_setup_link_generic(struct e1000_hw *hw)
{
        s32 ret_val;

        /* In the case of the phy reset being blocked, we already have a link.
         * We do not need to set it up again.
         */
        if (hw->phy.ops.check_reset_block && hw->phy.ops.check_reset_block(hw))
                return 0;

        /* If requested flow control is set to default, set flow control
         * based on the EEPROM flow control settings.
         */
        if (hw->fc.requested_mode == e1000_fc_default) {
                ret_val = e1000_set_default_fc_generic(hw);
                if (ret_val)
                        return ret_val;
        }

        /* Save off the requested flow control mode for use later.  Depending
         * on the link partner's capabilities, we may or may not use this mode.
         */
        hw->fc.current_mode = hw->fc.requested_mode;

        e_dbg("After fix-ups FlowControl is now = %x\n", hw->fc.current_mode);

        /* Call the necessary media_type subroutine to configure the link. */
        ret_val = hw->mac.ops.setup_physical_interface(hw);
        if (ret_val)
                return ret_val;

        /* Initialize the flow control address, type, and PAUSE timer
         * registers to their default values.  This is done even if flow
         * control is disabled, because it does not hurt anything to
         * initialize these registers.
         */
        e_dbg("Initializing the Flow Control address, type and timer regs\n");
        ew32(FCT, FLOW_CONTROL_TYPE);
        ew32(FCAH, FLOW_CONTROL_ADDRESS_HIGH);
        ew32(FCAL, FLOW_CONTROL_ADDRESS_LOW);

        ew32(FCTTV, hw->fc.pause_time);

        return e1000e_set_fc_watermarks(hw);
}

/**
 *  e1000_commit_fc_settings_generic - Configure flow control
 *  @hw: pointer to the HW structure
 *
 *  Write the flow control settings to the Transmit Config Word Register (TXCW)
 *  base on the flow control settings in e1000_mac_info.
 **/
static s32 e1000_commit_fc_settings_generic(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;
        u32 txcw;

        /* Check for a software override of the flow control settings, and
         * setup the device accordingly.  If auto-negotiation is enabled, then
         * software will have to set the "PAUSE" bits to the correct value in
         * the Transmit Config Word Register (TXCW) and re-start auto-
         * negotiation.  However, if auto-negotiation is disabled, then
         * software will have to manually configure the two flow control enable
         * bits in the CTRL register.
         *
         * The possible values of the "fc" parameter are:
         *      0:  Flow control is completely disabled
         *      1:  Rx flow control is enabled (we can receive pause frames,
         *          but not send pause frames).
         *      2:  Tx flow control is enabled (we can send pause frames but we
         *          do not support receiving pause frames).
         *      3:  Both Rx and Tx flow control (symmetric) are enabled.
         */
        switch (hw->fc.current_mode) {
        case e1000_fc_none:
                /* Flow control completely disabled by a software over-ride. */
                txcw = (E1000_TXCW_ANE | E1000_TXCW_FD);
                break;
        case e1000_fc_rx_pause:
                /* Rx Flow control is enabled and Tx Flow control is disabled
                 * by a software over-ride. Since there really isn't a way to
                 * advertise that we are capable of Rx Pause ONLY, we will
                 * advertise that we support both symmetric and asymmetric Rx
                 * PAUSE.  Later, we will disable the adapter's ability to send
                 * PAUSE frames.
                 */
                txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_PAUSE_MASK);
                break;
        case e1000_fc_tx_pause:
                /* Tx Flow control is enabled, and Rx Flow control is disabled,
                 * by a software over-ride.
                 */
                txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_ASM_DIR);
                break;
        case e1000_fc_full:
                /* Flow control (both Rx and Tx) is enabled by a software
                 * over-ride.
                 */
                txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_PAUSE_MASK);
                break;
        default:
                e_dbg("Flow control param set incorrectly\n");
                return -E1000_ERR_CONFIG;
        }

        ew32(TXCW, txcw);
        mac->txcw = txcw;

        return 0;
}

/**
 *  e1000_poll_fiber_serdes_link_generic - Poll for link up
 *  @hw: pointer to the HW structure
 *
 *  Polls for link up by reading the status register, if link fails to come
 *  up with auto-negotiation, then the link is forced if a signal is detected.
 **/
static s32 e1000_poll_fiber_serdes_link_generic(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;
        u32 i, status;
        s32 ret_val;

        /* If we have a signal (the cable is plugged in, or assumed true for
         * serdes media) then poll for a "Link-Up" indication in the Device
         * Status Register.  Time-out if a link isn't seen in 500 milliseconds
         * seconds (Auto-negotiation should complete in less than 500
         * milliseconds even if the other end is doing it in SW).
         */
        for (i = 0; i < FIBER_LINK_UP_LIMIT; i++) {
                usleep_range(10000, 20000);
                status = er32(STATUS);
                if (status & E1000_STATUS_LU)
                        break;
        }
        if (i == FIBER_LINK_UP_LIMIT) {
                e_dbg("Never got a valid link from auto-neg!!!\n");
                mac->autoneg_failed = true;
                /* AutoNeg failed to achieve a link, so we'll call
                 * mac->check_for_link. This routine will force the
                 * link up if we detect a signal. This will allow us to
                 * communicate with non-autonegotiating link partners.
                 */
                ret_val = mac->ops.check_for_link(hw);
                if (ret_val) {
                        e_dbg("Error while checking for link\n");
                        return ret_val;
                }
                mac->autoneg_failed = false;
        } else {
                mac->autoneg_failed = false;
                e_dbg("Valid Link Found\n");
        }

        return 0;
}

/**
 *  e1000e_setup_fiber_serdes_link - Setup link for fiber/serdes
 *  @hw: pointer to the HW structure
 *
 *  Configures collision distance and flow control for fiber and serdes
 *  links.  Upon successful setup, poll for link.
 **/
s32 e1000e_setup_fiber_serdes_link(struct e1000_hw *hw)
{
        u32 ctrl;
        s32 ret_val;

        ctrl = er32(CTRL);

        /* Take the link out of reset */
        ctrl &= ~E1000_CTRL_LRST;

        hw->mac.ops.config_collision_dist(hw);

        ret_val = e1000_commit_fc_settings_generic(hw);
        if (ret_val)
                return ret_val;

        /* Since auto-negotiation is enabled, take the link out of reset (the
         * link will be in reset, because we previously reset the chip). This
         * will restart auto-negotiation.  If auto-negotiation is successful
         * then the link-up status bit will be set and the flow control enable
         * bits (RFCE and TFCE) will be set according to their negotiated value.
         */
        e_dbg("Auto-negotiation enabled\n");

        ew32(CTRL, ctrl);
        e1e_flush();
        usleep_range(1000, 2000);

        /* For these adapters, the SW definable pin 1 is set when the optics
         * detect a signal.  If we have a signal, then poll for a "Link-Up"
         * indication.
         */
        if (hw->phy.media_type == e1000_media_type_internal_serdes ||
            (er32(CTRL) & E1000_CTRL_SWDPIN1)) {
                ret_val = e1000_poll_fiber_serdes_link_generic(hw);
        } else {
                e_dbg("No signal detected\n");
        }

        return ret_val;
}

/**
 *  e1000e_config_collision_dist_generic - Configure collision distance
 *  @hw: pointer to the HW structure
 *
 *  Configures the collision distance to the default value and is used
 *  during link setup.
 **/
void e1000e_config_collision_dist_generic(struct e1000_hw *hw)
{
        u32 tctl;

        tctl = er32(TCTL);

        tctl &= ~E1000_TCTL_COLD;
        tctl |= E1000_COLLISION_DISTANCE << E1000_COLD_SHIFT;

        ew32(TCTL, tctl);
        e1e_flush();
}

/**
 *  e1000e_set_fc_watermarks - Set flow control high/low watermarks
 *  @hw: pointer to the HW structure
 *
 *  Sets the flow control high/low threshold (watermark) registers.  If
 *  flow control XON frame transmission is enabled, then set XON frame
 *  transmission as well.
 **/
s32 e1000e_set_fc_watermarks(struct e1000_hw *hw)
{
        u32 fcrtl = 0, fcrth = 0;

        /* Set the flow control receive threshold registers.  Normally,
         * these registers will be set to a default threshold that may be
         * adjusted later by the driver's runtime code.  However, if the
         * ability to transmit pause frames is not enabled, then these
         * registers will be set to 0.
         */
        if (hw->fc.current_mode & e1000_fc_tx_pause) {
                /* We need to set up the Receive Threshold high and low water
                 * marks as well as (optionally) enabling the transmission of
                 * XON frames.
                 */
                fcrtl = hw->fc.low_water;
                if (hw->fc.send_xon)
                        fcrtl |= E1000_FCRTL_XONE;

                fcrth = hw->fc.high_water;
        }
        ew32(FCRTL, fcrtl);
        ew32(FCRTH, fcrth);

        return 0;
}

/**
 *  e1000e_force_mac_fc - Force the MAC's flow control settings
 *  @hw: pointer to the HW structure
 *
 *  Force the MAC's flow control settings.  Sets the TFCE and RFCE bits in the
 *  device control register to reflect the adapter settings.  TFCE and RFCE
 *  need to be explicitly set by software when a copper PHY is used because
 *  autonegotiation is managed by the PHY rather than the MAC.  Software must
 *  also configure these bits when link is forced on a fiber connection.
 **/
s32 e1000e_force_mac_fc(struct e1000_hw *hw)
{
        u32 ctrl;

        ctrl = er32(CTRL);

        /* Because we didn't get link via the internal auto-negotiation
         * mechanism (we either forced link or we got link via PHY
         * auto-neg), we have to manually enable/disable transmit an
         * receive flow control.
         *
         * The "Case" statement below enables/disable flow control
         * according to the "hw->fc.current_mode" parameter.
         *
         * The possible values of the "fc" parameter are:
         *      0:  Flow control is completely disabled
         *      1:  Rx flow control is enabled (we can receive pause
         *          frames but not send pause frames).
         *      2:  Tx flow control is enabled (we can send pause frames
         *          frames but we do not receive pause frames).
         *      3:  Both Rx and Tx flow control (symmetric) is enabled.
         *  other:  No other values should be possible at this point.
         */
        e_dbg("hw->fc.current_mode = %u\n", hw->fc.current_mode);

        switch (hw->fc.current_mode) {
        case e1000_fc_none:
                ctrl &= (~(E1000_CTRL_TFCE | E1000_CTRL_RFCE));
                break;
        case e1000_fc_rx_pause:
                ctrl &= (~E1000_CTRL_TFCE);
                ctrl |= E1000_CTRL_RFCE;
                break;
        case e1000_fc_tx_pause:
                ctrl &= (~E1000_CTRL_RFCE);
                ctrl |= E1000_CTRL_TFCE;
                break;
        case e1000_fc_full:
                ctrl |= (E1000_CTRL_TFCE | E1000_CTRL_RFCE);
                break;
        default:
                e_dbg("Flow control param set incorrectly\n");
                return -E1000_ERR_CONFIG;
        }

        ew32(CTRL, ctrl);

        return 0;
}

/**
 *  e1000e_config_fc_after_link_up - Configures flow control after link
 *  @hw: pointer to the HW structure
 *
 *  Checks the status of auto-negotiation after link up to ensure that the
 *  speed and duplex were not forced.  If the link needed to be forced, then
 *  flow control needs to be forced also.  If auto-negotiation is enabled
 *  and did not fail, then we configure flow control based on our link
 *  partner.
 **/
s32 e1000e_config_fc_after_link_up(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;
        s32 ret_val = 0;
        u32 pcs_status_reg, pcs_adv_reg, pcs_lp_ability_reg, pcs_ctrl_reg;
        u16 mii_status_reg, mii_nway_adv_reg, mii_nway_lp_ability_reg;
        u16 speed, duplex;

        /* Check for the case where we have fiber media and auto-neg failed
         * so we had to force link.  In this case, we need to force the
         * configuration of the MAC to match the "fc" parameter.
         */
        if (mac->autoneg_failed) {
                if (hw->phy.media_type == e1000_media_type_fiber ||
                    hw->phy.media_type == e1000_media_type_internal_serdes)
                        ret_val = e1000e_force_mac_fc(hw);
        } else {
                if (hw->phy.media_type == e1000_media_type_copper)
                        ret_val = e1000e_force_mac_fc(hw);
        }

        if (ret_val) {
                e_dbg("Error forcing flow control settings\n");
                return ret_val;
        }

        /* Check for the case where we have copper media and auto-neg is
         * enabled.  In this case, we need to check and see if Auto-Neg
         * has completed, and if so, how the PHY and link partner has
         * flow control configured.
         */
        if ((hw->phy.media_type == e1000_media_type_copper) && mac->autoneg) {
                /* Read the MII Status Register and check to see if AutoNeg
                 * has completed.  We read this twice because this reg has
                 * some "sticky" (latched) bits.
                 */
                ret_val = e1e_rphy(hw, MII_BMSR, &mii_status_reg);
                if (ret_val)
                        return ret_val;
                ret_val = e1e_rphy(hw, MII_BMSR, &mii_status_reg);
                if (ret_val)
                        return ret_val;

                if (!(mii_status_reg & BMSR_ANEGCOMPLETE)) {
                        e_dbg("Copper PHY and Auto Neg has not completed.\n");
                        return ret_val;
                }

                /* The AutoNeg process has completed, so we now need to
                 * read both the Auto Negotiation Advertisement
                 * Register (Address 4) and the Auto_Negotiation Base
                 * Page Ability Register (Address 5) to determine how
                 * flow control was negotiated.
                 */
                ret_val = e1e_rphy(hw, MII_ADVERTISE, &mii_nway_adv_reg);
                if (ret_val)
                        return ret_val;
                ret_val = e1e_rphy(hw, MII_LPA, &mii_nway_lp_ability_reg);
                if (ret_val)
                        return ret_val;

                /* Two bits in the Auto Negotiation Advertisement Register
                 * (Address 4) and two bits in the Auto Negotiation Base
                 * Page Ability Register (Address 5) determine flow control
                 * for both the PHY and the link partner.  The following
                 * table, taken out of the IEEE 802.3ab/D6.0 dated March 25,
                 * 1999, describes these PAUSE resolution bits and how flow
                 * control is determined based upon these settings.
                 * NOTE:  DC = Don't Care
                 *
                 *   LOCAL DEVICE  |   LINK PARTNER
                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution
                 *-------|---------|-------|---------|--------------------
                 *   0   |    0    |  DC   |   DC    | e1000_fc_none
                 *   0   |    1    |   0   |   DC    | e1000_fc_none
                 *   0   |    1    |   1   |    0    | e1000_fc_none
                 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
                 *   1   |    0    |   0   |   DC    | e1000_fc_none
                 *   1   |   DC    |   1   |   DC    | e1000_fc_full
                 *   1   |    1    |   0   |    0    | e1000_fc_none
                 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
                 *
                 * Are both PAUSE bits set to 1?  If so, this implies
                 * Symmetric Flow Control is enabled at both ends.  The
                 * ASM_DIR bits are irrelevant per the spec.
                 *
                 * For Symmetric Flow Control:
                 *
                 *   LOCAL DEVICE  |   LINK PARTNER
                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
                 *-------|---------|-------|---------|--------------------
                 *   1   |   DC    |   1   |   DC    | E1000_fc_full
                 *
                 */
                if ((mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
                    (mii_nway_lp_ability_reg & LPA_PAUSE_CAP)) {
                        /* Now we need to check if the user selected Rx ONLY
                         * of pause frames.  In this case, we had to advertise
                         * FULL flow control because we could not advertise Rx
                         * ONLY. Hence, we must now check to see if we need to
                         * turn OFF the TRANSMISSION of PAUSE frames.
                         */
                        if (hw->fc.requested_mode == e1000_fc_full) {
                                hw->fc.current_mode = e1000_fc_full;
                                e_dbg("Flow Control = FULL.\n");
                        } else {
                                hw->fc.current_mode = e1000_fc_rx_pause;
                                e_dbg("Flow Control = Rx PAUSE frames only.\n");
                        }
                }
                /* For receiving PAUSE frames ONLY.
                 *
                 *   LOCAL DEVICE  |   LINK PARTNER
                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
                 *-------|---------|-------|---------|--------------------
                 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
                 */
                else if (!(mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
                         (mii_nway_adv_reg & ADVERTISE_PAUSE_ASYM) &&
                         (mii_nway_lp_ability_reg & LPA_PAUSE_CAP) &&
                         (mii_nway_lp_ability_reg & LPA_PAUSE_ASYM)) {
                        hw->fc.current_mode = e1000_fc_tx_pause;
                        e_dbg("Flow Control = Tx PAUSE frames only.\n");
                }
                /* For transmitting PAUSE frames ONLY.
                 *
                 *   LOCAL DEVICE  |   LINK PARTNER
                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
                 *-------|---------|-------|---------|--------------------
                 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
                 */
                else if ((mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
                         (mii_nway_adv_reg & ADVERTISE_PAUSE_ASYM) &&
                         !(mii_nway_lp_ability_reg & LPA_PAUSE_CAP) &&
                         (mii_nway_lp_ability_reg & LPA_PAUSE_ASYM)) {
                        hw->fc.current_mode = e1000_fc_rx_pause;
                        e_dbg("Flow Control = Rx PAUSE frames only.\n");
                } else {
                        /* Per the IEEE spec, at this point flow control
                         * should be disabled.
                         */
                        hw->fc.current_mode = e1000_fc_none;
                        e_dbg("Flow Control = NONE.\n");
                }

                /* Now we need to do one last check...  If we auto-
                 * negotiated to HALF DUPLEX, flow control should not be
                 * enabled per IEEE 802.3 spec.
                 */
                ret_val = mac->ops.get_link_up_info(hw, &speed, &duplex);
                if (ret_val) {
                        e_dbg("Error getting link speed and duplex\n");
                        return ret_val;
                }

                if (duplex == HALF_DUPLEX)
                        hw->fc.current_mode = e1000_fc_none;

                /* Now we call a subroutine to actually force the MAC
                 * controller to use the correct flow control settings.
                 */
                ret_val = e1000e_force_mac_fc(hw);
                if (ret_val) {
                        e_dbg("Error forcing flow control settings\n");
                        return ret_val;
                }
        }

        /* Check for the case where we have SerDes media and auto-neg is
         * enabled.  In this case, we need to check and see if Auto-Neg
         * has completed, and if so, how the PHY and link partner has
         * flow control configured.
         */
        if ((hw->phy.media_type == e1000_media_type_internal_serdes) &&
            mac->autoneg) {
                /* Read the PCS_LSTS and check to see if AutoNeg
                 * has completed.
                 */
                pcs_status_reg = er32(PCS_LSTAT);

                if (!(pcs_status_reg & E1000_PCS_LSTS_AN_COMPLETE)) {
                        e_dbg("PCS Auto Neg has not completed.\n");
                        return ret_val;
                }

                /* The AutoNeg process has completed, so we now need to
                 * read both the Auto Negotiation Advertisement
                 * Register (PCS_ANADV) and the Auto_Negotiation Base
                 * Page Ability Register (PCS_LPAB) to determine how
                 * flow control was negotiated.
                 */
                pcs_adv_reg = er32(PCS_ANADV);
                pcs_lp_ability_reg = er32(PCS_LPAB);

                /* Two bits in the Auto Negotiation Advertisement Register
                 * (PCS_ANADV) and two bits in the Auto Negotiation Base
                 * Page Ability Register (PCS_LPAB) determine flow control
                 * for both the PHY and the link partner.  The following
                 * table, taken out of the IEEE 802.3ab/D6.0 dated March 25,
                 * 1999, describes these PAUSE resolution bits and how flow
                 * control is determined based upon these settings.
                 * NOTE:  DC = Don't Care
                 *
                 *   LOCAL DEVICE  |   LINK PARTNER
                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution
                 *-------|---------|-------|---------|--------------------
                 *   0   |    0    |  DC   |   DC    | e1000_fc_none
                 *   0   |    1    |   0   |   DC    | e1000_fc_none
                 *   0   |    1    |   1   |    0    | e1000_fc_none
                 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
                 *   1   |    0    |   0   |   DC    | e1000_fc_none
                 *   1   |   DC    |   1   |   DC    | e1000_fc_full
                 *   1   |    1    |   0   |    0    | e1000_fc_none
                 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
                 *
                 * Are both PAUSE bits set to 1?  If so, this implies
                 * Symmetric Flow Control is enabled at both ends.  The
                 * ASM_DIR bits are irrelevant per the spec.
                 *
                 * For Symmetric Flow Control:
                 *
                 *   LOCAL DEVICE  |   LINK PARTNER
                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
                 *-------|---------|-------|---------|--------------------
                 *   1   |   DC    |   1   |   DC    | e1000_fc_full
                 *
                 */
                if ((pcs_adv_reg & E1000_TXCW_PAUSE) &&
                    (pcs_lp_ability_reg & E1000_TXCW_PAUSE)) {
                        /* Now we need to check if the user selected Rx ONLY
                         * of pause frames.  In this case, we had to advertise
                         * FULL flow control because we could not advertise Rx
                         * ONLY. Hence, we must now check to see if we need to
                         * turn OFF the TRANSMISSION of PAUSE frames.
                         */
                        if (hw->fc.requested_mode == e1000_fc_full) {
                                hw->fc.current_mode = e1000_fc_full;
                                e_dbg("Flow Control = FULL.\n");
                        } else {
                                hw->fc.current_mode = e1000_fc_rx_pause;
                                e_dbg("Flow Control = Rx PAUSE frames only.\n");
                        }
                }
                /* For receiving PAUSE frames ONLY.
                 *
                 *   LOCAL DEVICE  |   LINK PARTNER
                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
                 *-------|---------|-------|---------|--------------------
                 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
                 */
                else if (!(pcs_adv_reg & E1000_TXCW_PAUSE) &&
                         (pcs_adv_reg & E1000_TXCW_ASM_DIR) &&
                         (pcs_lp_ability_reg & E1000_TXCW_PAUSE) &&
                         (pcs_lp_ability_reg & E1000_TXCW_ASM_DIR)) {
                        hw->fc.current_mode = e1000_fc_tx_pause;
                        e_dbg("Flow Control = Tx PAUSE frames only.\n");
                }
                /* For transmitting PAUSE frames ONLY.
                 *
                 *   LOCAL DEVICE  |   LINK PARTNER
                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
                 *-------|---------|-------|---------|--------------------
                 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
                 */
                else if ((pcs_adv_reg & E1000_TXCW_PAUSE) &&
                         (pcs_adv_reg & E1000_TXCW_ASM_DIR) &&
                         !(pcs_lp_ability_reg & E1000_TXCW_PAUSE) &&
                         (pcs_lp_ability_reg & E1000_TXCW_ASM_DIR)) {
                        hw->fc.current_mode = e1000_fc_rx_pause;
                        e_dbg("Flow Control = Rx PAUSE frames only.\n");
                } else {
                        /* Per the IEEE spec, at this point flow control
                         * should be disabled.
                         */
                        hw->fc.current_mode = e1000_fc_none;
                        e_dbg("Flow Control = NONE.\n");
                }

                /* Now we call a subroutine to actually force the MAC
                 * controller to use the correct flow control settings.
                 */
                pcs_ctrl_reg = er32(PCS_LCTL);
                pcs_ctrl_reg |= E1000_PCS_LCTL_FORCE_FCTRL;
                ew32(PCS_LCTL, pcs_ctrl_reg);

                ret_val = e1000e_force_mac_fc(hw);
                if (ret_val) {
                        e_dbg("Error forcing flow control settings\n");
                        return ret_val;
                }
        }

        return 0;
}

/**
 *  e1000e_get_speed_and_duplex_copper - Retrieve current speed/duplex
 *  @hw: pointer to the HW structure
 *  @speed: stores the current speed
 *  @duplex: stores the current duplex
 *
 *  Read the status register for the current speed/duplex and store the current
 *  speed and duplex for copper connections.
 **/
s32 e1000e_get_speed_and_duplex_copper(struct e1000_hw *hw, u16 *speed,
                                       u16 *duplex)
{
        u32 status;

        status = er32(STATUS);
        if (status & E1000_STATUS_SPEED_1000)
                *speed = SPEED_1000;
        else if (status & E1000_STATUS_SPEED_100)
                *speed = SPEED_100;
        else
                *speed = SPEED_10;

        if (status & E1000_STATUS_FD)
                *duplex = FULL_DUPLEX;
        else
                *duplex = HALF_DUPLEX;

        e_dbg("%u Mbps, %s Duplex\n",
              *speed == SPEED_1000 ? 1000 : *speed == SPEED_100 ? 100 : 10,
              *duplex == FULL_DUPLEX ? "Full" : "Half");

        return 0;
}

/**
 *  e1000e_get_speed_and_duplex_fiber_serdes - Retrieve current speed/duplex
 *  @hw: pointer to the HW structure
 *  @speed: stores the current speed
 *  @duplex: stores the current duplex
 *
 *  Sets the speed and duplex to gigabit full duplex (the only possible option)
 *  for fiber/serdes links.
 **/
s32 e1000e_get_speed_and_duplex_fiber_serdes(struct e1000_hw __always_unused
                                             *hw, u16 *speed, u16 *duplex)
{
        *speed = SPEED_1000;
        *duplex = FULL_DUPLEX;

        return 0;
}

/**
 *  e1000e_get_hw_semaphore - Acquire hardware semaphore
 *  @hw: pointer to the HW structure
 *
 *  Acquire the HW semaphore to access the PHY or NVM
 **/
s32 e1000e_get_hw_semaphore(struct e1000_hw *hw)
{
        u32 swsm;
        s32 timeout = hw->nvm.word_size + 1;
        s32 i = 0;

        /* Get the SW semaphore */
        while (i < timeout) {
                swsm = er32(SWSM);
                if (!(swsm & E1000_SWSM_SMBI))
                        break;

                usleep_range(50, 100);
                i++;
        }

        if (i == timeout) {
                e_dbg("Driver can't access device - SMBI bit is set.\n");
                return -E1000_ERR_NVM;
        }

        /* Get the FW semaphore. */
        for (i = 0; i < timeout; i++) {
                swsm = er32(SWSM);
                ew32(SWSM, swsm | E1000_SWSM_SWESMBI);

                /* Semaphore acquired if bit latched */
                if (er32(SWSM) & E1000_SWSM_SWESMBI)
                        break;

                usleep_range(50, 100);
        }

        if (i == timeout) {
                /* Release semaphores */
                e1000e_put_hw_semaphore(hw);
                e_dbg("Driver can't access the NVM\n");
                return -E1000_ERR_NVM;
        }

        return 0;
}

/**
 *  e1000e_put_hw_semaphore - Release hardware semaphore
 *  @hw: pointer to the HW structure
 *
 *  Release hardware semaphore used to access the PHY or NVM
 **/
void e1000e_put_hw_semaphore(struct e1000_hw *hw)
{
        u32 swsm;

        swsm = er32(SWSM);
        swsm &= ~(E1000_SWSM_SMBI | E1000_SWSM_SWESMBI);
        ew32(SWSM, swsm);
}

/**
 *  e1000e_get_auto_rd_done - Check for auto read completion
 *  @hw: pointer to the HW structure
 *
 *  Check EEPROM for Auto Read done bit.
 **/
s32 e1000e_get_auto_rd_done(struct e1000_hw *hw)
{
        s32 i = 0;

        while (i < AUTO_READ_DONE_TIMEOUT) {
                if (er32(EECD) & E1000_EECD_AUTO_RD)
                        break;
                usleep_range(1000, 2000);
                i++;
        }

        if (i == AUTO_READ_DONE_TIMEOUT) {
                e_dbg("Auto read by HW from NVM has not completed.\n");
                return -E1000_ERR_RESET;
        }

        return 0;
}

/**
 *  e1000e_valid_led_default - Verify a valid default LED config
 *  @hw: pointer to the HW structure
 *  @data: pointer to the NVM (EEPROM)
 *
 *  Read the EEPROM for the current default LED configuration.  If the
 *  LED configuration is not valid, set to a valid LED configuration.
 **/
s32 e1000e_valid_led_default(struct e1000_hw *hw, u16 *data)
{
        s32 ret_val;

        ret_val = e1000_read_nvm(hw, NVM_ID_LED_SETTINGS, 1, data);
        if (ret_val) {
                e_dbg("NVM Read Error\n");
                return ret_val;
        }

        if (*data == ID_LED_RESERVED_0000 || *data == ID_LED_RESERVED_FFFF)
                *data = ID_LED_DEFAULT;

        return 0;
}

/**
 *  e1000e_id_led_init_generic -
 *  @hw: pointer to the HW structure
 *
 **/
s32 e1000e_id_led_init_generic(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;
        s32 ret_val;
        const u32 ledctl_mask = 0x000000FF;
        const u32 ledctl_on = E1000_LEDCTL_MODE_LED_ON;
        const u32 ledctl_off = E1000_LEDCTL_MODE_LED_OFF;
        u16 data, i, temp;
        const u16 led_mask = 0x0F;

        ret_val = hw->nvm.ops.valid_led_default(hw, &data);
        if (ret_val)
                return ret_val;

        mac->ledctl_default = er32(LEDCTL);
        mac->ledctl_mode1 = mac->ledctl_default;
        mac->ledctl_mode2 = mac->ledctl_default;

        for (i = 0; i < 4; i++) {
                temp = (data >> (i << 2)) & led_mask;
                switch (temp) {
                case ID_LED_ON1_DEF2:
                case ID_LED_ON1_ON2:
                case ID_LED_ON1_OFF2:
                        mac->ledctl_mode1 &= ~(ledctl_mask << (i << 3));
                        mac->ledctl_mode1 |= ledctl_on << (i << 3);
                        break;
                case ID_LED_OFF1_DEF2:
                case ID_LED_OFF1_ON2:
                case ID_LED_OFF1_OFF2:
                        mac->ledctl_mode1 &= ~(ledctl_mask << (i << 3));
                        mac->ledctl_mode1 |= ledctl_off << (i << 3);
                        break;
                default:
                        /* Do nothing */
                        break;
                }
                switch (temp) {
                case ID_LED_DEF1_ON2:
                case ID_LED_ON1_ON2:
                case ID_LED_OFF1_ON2:
                        mac->ledctl_mode2 &= ~(ledctl_mask << (i << 3));
                        mac->ledctl_mode2 |= ledctl_on << (i << 3);
                        break;
                case ID_LED_DEF1_OFF2:
                case ID_LED_ON1_OFF2:
                case ID_LED_OFF1_OFF2:
                        mac->ledctl_mode2 &= ~(ledctl_mask << (i << 3));
                        mac->ledctl_mode2 |= ledctl_off << (i << 3);
                        break;
                default:
                        /* Do nothing */
                        break;
                }
        }

        return 0;
}

/**
 *  e1000e_setup_led_generic - Configures SW controllable LED
 *  @hw: pointer to the HW structure
 *
 *  This prepares the SW controllable LED for use and saves the current state
 *  of the LED so it can be later restored.
 **/
s32 e1000e_setup_led_generic(struct e1000_hw *hw)
{
        u32 ledctl;

        if (hw->mac.ops.setup_led != e1000e_setup_led_generic)
                return -E1000_ERR_CONFIG;

        if (hw->phy.media_type == e1000_media_type_fiber) {
                ledctl = er32(LEDCTL);
                hw->mac.ledctl_default = ledctl;
                /* Turn off LED0 */
                ledctl &= ~(E1000_LEDCTL_LED0_IVRT | E1000_LEDCTL_LED0_BLINK |
                            E1000_LEDCTL_LED0_MODE_MASK);
                ledctl |= (E1000_LEDCTL_MODE_LED_OFF <<
                           E1000_LEDCTL_LED0_MODE_SHIFT);
                ew32(LEDCTL, ledctl);
        } else if (hw->phy.media_type == e1000_media_type_copper) {
                ew32(LEDCTL, hw->mac.ledctl_mode1);
        }

        return 0;
}

/**
 *  e1000e_cleanup_led_generic - Set LED config to default operation
 *  @hw: pointer to the HW structure
 *
 *  Remove the current LED configuration and set the LED configuration
 *  to the default value, saved from the EEPROM.
 **/
s32 e1000e_cleanup_led_generic(struct e1000_hw *hw)
{
        ew32(LEDCTL, hw->mac.ledctl_default);
        return 0;
}

/**
 *  e1000e_blink_led_generic - Blink LED
 *  @hw: pointer to the HW structure
 *
 *  Blink the LEDs which are set to be on.
 **/
s32 e1000e_blink_led_generic(struct e1000_hw *hw)
{
        u32 ledctl_blink = 0;
        u32 i;

        if (hw->phy.media_type == e1000_media_type_fiber) {
                /* always blink LED0 for PCI-E fiber */
                ledctl_blink = E1000_LEDCTL_LED0_BLINK |
                    (E1000_LEDCTL_MODE_LED_ON << E1000_LEDCTL_LED0_MODE_SHIFT);
        } else {
                /* Set the blink bit for each LED that's "on" (0x0E)
                 * (or "off" if inverted) in ledctl_mode2.  The blink
                 * logic in hardware only works when mode is set to "on"
                 * so it must be changed accordingly when the mode is
                 * "off" and inverted.
                 */
                ledctl_blink = hw->mac.ledctl_mode2;
                for (i = 0; i < 32; i += 8) {
                        u32 mode = (hw->mac.ledctl_mode2 >> i) &
                            E1000_LEDCTL_LED0_MODE_MASK;
                        u32 led_default = hw->mac.ledctl_default >> i;

                        if ((!(led_default & E1000_LEDCTL_LED0_IVRT) &&
                             (mode == E1000_LEDCTL_MODE_LED_ON)) ||
                            ((led_default & E1000_LEDCTL_LED0_IVRT) &&
                             (mode == E1000_LEDCTL_MODE_LED_OFF))) {
                                ledctl_blink &=
                                    ~(E1000_LEDCTL_LED0_MODE_MASK << i);
                                ledctl_blink |= (E1000_LEDCTL_LED0_BLINK |
                                                 E1000_LEDCTL_MODE_LED_ON) << i;
                        }
                }
        }

        ew32(LEDCTL, ledctl_blink);

        return 0;
}

/**
 *  e1000e_led_on_generic - Turn LED on
 *  @hw: pointer to the HW structure
 *
 *  Turn LED on.
 **/
s32 e1000e_led_on_generic(struct e1000_hw *hw)
{
        u32 ctrl;

        switch (hw->phy.media_type) {
        case e1000_media_type_fiber:
                ctrl = er32(CTRL);
                ctrl &= ~E1000_CTRL_SWDPIN0;
                ctrl |= E1000_CTRL_SWDPIO0;
                ew32(CTRL, ctrl);
                break;
        case e1000_media_type_copper:
                ew32(LEDCTL, hw->mac.ledctl_mode2);
                break;
        default:
                break;
        }

        return 0;
}

/**
 *  e1000e_led_off_generic - Turn LED off
 *  @hw: pointer to the HW structure
 *
 *  Turn LED off.
 **/
s32 e1000e_led_off_generic(struct e1000_hw *hw)
{
        u32 ctrl;

        switch (hw->phy.media_type) {
        case e1000_media_type_fiber:
                ctrl = er32(CTRL);
                ctrl |= E1000_CTRL_SWDPIN0;
                ctrl |= E1000_CTRL_SWDPIO0;
                ew32(CTRL, ctrl);
                break;
        case e1000_media_type_copper:
                ew32(LEDCTL, hw->mac.ledctl_mode1);
                break;
        default:
                break;
        }

        return 0;
}

/**
 *  e1000e_set_pcie_no_snoop - Set PCI-express capabilities
 *  @hw: pointer to the HW structure
 *  @no_snoop: bitmap of snoop events
 *
 *  Set the PCI-express register to snoop for events enabled in 'no_snoop'.
 **/
void e1000e_set_pcie_no_snoop(struct e1000_hw *hw, u32 no_snoop)
{
        u32 gcr;

        if (no_snoop) {
                gcr = er32(GCR);
                gcr &= ~(PCIE_NO_SNOOP_ALL);
                gcr |= no_snoop;
                ew32(GCR, gcr);
        }
}

/**
 *  e1000e_disable_pcie_master - Disables PCI-express master access
 *  @hw: pointer to the HW structure
 *
 *  Returns 0 if successful, else returns -10
 *  (-E1000_ERR_MASTER_REQUESTS_PENDING) if master disable bit has not caused
 *  the master requests to be disabled.
 *
 *  Disables PCI-Express master access and verifies there are no pending
 *  requests.
 **/
s32 e1000e_disable_pcie_master(struct e1000_hw *hw)
{
        u32 ctrl;
        s32 timeout = MASTER_DISABLE_TIMEOUT;

        ctrl = er32(CTRL);
        ctrl |= E1000_CTRL_GIO_MASTER_DISABLE;
        ew32(CTRL, ctrl);

        while (timeout) {
                if (!(er32(STATUS) & E1000_STATUS_GIO_MASTER_ENABLE))
                        break;
                usleep_range(100, 200);
                timeout--;
        }

        if (!timeout) {
                e_dbg("Master requests are pending.\n");
                return -E1000_ERR_MASTER_REQUESTS_PENDING;
        }

        return 0;
}

/**
 *  e1000e_reset_adaptive - Reset Adaptive Interframe Spacing
 *  @hw: pointer to the HW structure
 *
 *  Reset the Adaptive Interframe Spacing throttle to default values.
 **/
void e1000e_reset_adaptive(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;

        if (!mac->adaptive_ifs) {
                e_dbg("Not in Adaptive IFS mode!\n");
                return;
        }

        mac->current_ifs_val = 0;
        mac->ifs_min_val = IFS_MIN;
        mac->ifs_max_val = IFS_MAX;
        mac->ifs_step_size = IFS_STEP;
        mac->ifs_ratio = IFS_RATIO;

        mac->in_ifs_mode = false;
        ew32(AIT, 0);
}

/**
 *  e1000e_update_adaptive - Update Adaptive Interframe Spacing
 *  @hw: pointer to the HW structure
 *
 *  Update the Adaptive Interframe Spacing Throttle value based on the
 *  time between transmitted packets and time between collisions.
 **/
void e1000e_update_adaptive(struct e1000_hw *hw)
{
        struct e1000_mac_info *mac = &hw->mac;

        if (!mac->adaptive_ifs) {
                e_dbg("Not in Adaptive IFS mode!\n");
                return;
        }

        if ((mac->collision_delta * mac->ifs_ratio) > mac->tx_packet_delta) {
                if (mac->tx_packet_delta > MIN_NUM_XMITS) {
                        mac->in_ifs_mode = true;
                        if (mac->current_ifs_val < mac->ifs_max_val) {
                                if (!mac->current_ifs_val)
                                        mac->current_ifs_val = mac->ifs_min_val;
                                else
                                        mac->current_ifs_val +=
                                            mac->ifs_step_size;
                                ew32(AIT, mac->current_ifs_val);
                        }
                }
        } else {
                if (mac->in_ifs_mode &&
                    (mac->tx_packet_delta <= MIN_NUM_XMITS)) {
                        mac->current_ifs_val = 0;
                        mac->in_ifs_mode = false;
                        ew32(AIT, 0);
                }
        }
}