e1000_mac.c

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/*******************************************************************************

  Intel(R) Gigabit Ethernet Linux driver
  Copyright(c) 2007-2012 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.

  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

  The full GNU General Public License is included in this distribution in
  the file called "COPYING".

  Contact Information:
  e1000-devel Mailing List <[email protected]>
  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497

*******************************************************************************/

#include <linux/if_ether.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>

#include "e1000_mac.h"

#include "igb.h"

static s32 igb_set_default_fc(struct e1000_hw *hw);
static s32 igb_set_fc_watermarks(struct e1000_hw *hw);

s32 igb_get_bus_info_pcie(struct e1000_hw *hw)
{
    struct e1000_bus_info *bus = &hw->bus;
    s32 ret_val;
    u32 reg;
    u16 pcie_link_status;

    bus->type = e1000_bus_type_pci_express;

    ret_val = igb_read_pcie_cap_reg(hw,
                    PCI_EXP_LNKSTA,
                    &pcie_link_status);
    if (ret_val) {
        bus->width = e1000_bus_width_unknown;
        bus->speed = e1000_bus_speed_unknown;
    } else {
        switch (pcie_link_status & PCI_EXP_LNKSTA_CLS) {
        case PCI_EXP_LNKSTA_CLS_2_5GB:
            bus->speed = e1000_bus_speed_2500;
            break;
        case PCI_EXP_LNKSTA_CLS_5_0GB:
            bus->speed = e1000_bus_speed_5000;
            break;
        default:
            bus->speed = e1000_bus_speed_unknown;
            break;
        }

        bus->width = (enum e1000_bus_width)((pcie_link_status &
                             PCI_EXP_LNKSTA_NLW) >>
                             PCI_EXP_LNKSTA_NLW_SHIFT);
    }

    reg = rd32(E1000_STATUS);
    bus->func = (reg & E1000_STATUS_FUNC_MASK) >> E1000_STATUS_FUNC_SHIFT;

    return 0;
}

void igb_clear_vfta(struct e1000_hw *hw)
{
    u32 offset;

    for (offset = 0; offset < E1000_VLAN_FILTER_TBL_SIZE; offset++) {
        array_wr32(E1000_VFTA, offset, 0);
        wrfl();
    }
}

static void igb_write_vfta(struct e1000_hw *hw, u32 offset, u32 value)
{
    array_wr32(E1000_VFTA, offset, value);
    wrfl();
}

/* Due to a hw errata, if the host tries to  configure the VFTA register
 * while performing queries from the BMC or DMA, then the VFTA in some
 * cases won't be written.
 */

void igb_clear_vfta_i350(struct e1000_hw *hw)
{
    u32 offset;
    int i;

    for (offset = 0; offset < E1000_VLAN_FILTER_TBL_SIZE; offset++) {
        for (i = 0; i < 10; i++)
            array_wr32(E1000_VFTA, offset, 0);

        wrfl();
    }
}

static void igb_write_vfta_i350(struct e1000_hw *hw, u32 offset, u32 value)
{
    int i;

    for (i = 0; i < 10; i++)
        array_wr32(E1000_VFTA, offset, value);

    wrfl();
}

void igb_init_rx_addrs(struct e1000_hw *hw, u16 rar_count)
{
    u32 i;
    u8 mac_addr[ETH_ALEN] = {0};

    /* Setup the receive address */
    hw_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 */
    hw_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);
}

s32 igb_vfta_set(struct e1000_hw *hw, u32 vid, bool add)
{
    u32 index = (vid >> E1000_VFTA_ENTRY_SHIFT) & E1000_VFTA_ENTRY_MASK;
    u32 mask = 1 << (vid & E1000_VFTA_ENTRY_BIT_SHIFT_MASK);
    u32 vfta;
    struct igb_adapter *adapter = hw->back;
    s32 ret_val = 0;

    vfta = adapter->shadow_vfta[index];

    /* bit was set/cleared before we started */
    if ((!!(vfta & mask)) == add) {
        ret_val = -E1000_ERR_CONFIG;
    } else {
        if (add)
            vfta |= mask;
        else
            vfta &= ~mask;
    }
    if (hw->mac.type == e1000_i350)
        igb_write_vfta_i350(hw, index, vfta);
    else
        igb_write_vfta(hw, index, vfta);
    adapter->shadow_vfta[index] = vfta;

    return ret_val;
}

s32 igb_check_alt_mac_addr(struct e1000_hw *hw)
{
    u32 i;
    s32 ret_val = 0;
    u16 offset, nvm_alt_mac_addr_offset, nvm_data;
    u8 alt_mac_addr[ETH_ALEN];

    /*
     * Alternate MAC address is handled by the option ROM for 82580
     * and newer. SW support not required.
     */
    if (hw->mac.type >= e1000_82580)
        goto out;

    ret_val = hw->nvm.ops.read(hw, NVM_ALT_MAC_ADDR_PTR, 1,
                 &nvm_alt_mac_addr_offset);
    if (ret_val) {
        hw_dbg("NVM Read Error\n");
        goto out;
    }

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

    if (hw->bus.func == E1000_FUNC_1)
        nvm_alt_mac_addr_offset += E1000_ALT_MAC_ADDRESS_OFFSET_LAN1;
    if (hw->bus.func == E1000_FUNC_2)
        nvm_alt_mac_addr_offset += E1000_ALT_MAC_ADDRESS_OFFSET_LAN2;

    if (hw->bus.func == E1000_FUNC_3)
        nvm_alt_mac_addr_offset += E1000_ALT_MAC_ADDRESS_OFFSET_LAN3;
    for (i = 0; i < ETH_ALEN; i += 2) {
        offset = nvm_alt_mac_addr_offset + (i >> 1);
        ret_val = hw->nvm.ops.read(hw, offset, 1, &nvm_data);
        if (ret_val) {
            hw_dbg("NVM Read Error\n");
            goto out;
        }

        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)) {
        hw_dbg("Ignoring Alternate Mac Address with MC bit set\n");
        goto out;
    }

    /*
     * 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);

out:
    return ret_val;
}

void igb_rar_set(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.
     */
    wr32(E1000_RAL(index), rar_low);
    wrfl();
    wr32(E1000_RAH(index), rar_high);
    wrfl();
}

void igb_mta_set(struct e1000_hw *hw, u32 hash_value)
{
    u32 hash_bit, hash_reg, mta;

    /*
     * The MTA is a register array of 32-bit registers. It is
     * treated like an array of (32*mta_reg_count) bits.  We want to
     * set bit BitArray[hash_value]. So we figure out what register
     * the bit is in, read it, OR in the new bit, then write
     * back the new value.  The (hw->mac.mta_reg_count - 1) serves as a
     * mask to bits 31:5 of the hash value which gives us the
     * register we're modifying.  The hash bit within that register
     * is determined by the lower 5 bits of the hash value.
     */
    hash_reg = (hash_value >> 5) & (hw->mac.mta_reg_count - 1);
    hash_bit = hash_value & 0x1F;

    mta = array_rd32(E1000_MTA, hash_reg);

    mta |= (1 << hash_bit);

    array_wr32(E1000_MTA, hash_reg, mta);
    wrfl();
}

static u32 igb_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;
}

void igb_update_mc_addr_list(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 = igb_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] |= (1 << hash_bit);
        mc_addr_list += (ETH_ALEN);
    }

    /* replace the entire MTA table */
    for (i = hw->mac.mta_reg_count - 1; i >= 0; i--)
        array_wr32(E1000_MTA, i, hw->mac.mta_shadow[i]);
    wrfl();
}

void igb_clear_hw_cntrs_base(struct e1000_hw *hw)
{
    rd32(E1000_CRCERRS);
    rd32(E1000_SYMERRS);
    rd32(E1000_MPC);
    rd32(E1000_SCC);
    rd32(E1000_ECOL);
    rd32(E1000_MCC);
    rd32(E1000_LATECOL);
    rd32(E1000_COLC);
    rd32(E1000_DC);
    rd32(E1000_SEC);
    rd32(E1000_RLEC);
    rd32(E1000_XONRXC);
    rd32(E1000_XONTXC);
    rd32(E1000_XOFFRXC);
    rd32(E1000_XOFFTXC);
    rd32(E1000_FCRUC);
    rd32(E1000_GPRC);
    rd32(E1000_BPRC);
    rd32(E1000_MPRC);
    rd32(E1000_GPTC);
    rd32(E1000_GORCL);
    rd32(E1000_GORCH);
    rd32(E1000_GOTCL);
    rd32(E1000_GOTCH);
    rd32(E1000_RNBC);
    rd32(E1000_RUC);
    rd32(E1000_RFC);
    rd32(E1000_ROC);
    rd32(E1000_RJC);
    rd32(E1000_TORL);
    rd32(E1000_TORH);
    rd32(E1000_TOTL);
    rd32(E1000_TOTH);
    rd32(E1000_TPR);
    rd32(E1000_TPT);
    rd32(E1000_MPTC);
    rd32(E1000_BPTC);
}

s32 igb_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) {
        ret_val = 0;
        goto out;
    }

    /*
     * 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 = igb_phy_has_link(hw, 1, 0, &link);
    if (ret_val)
        goto out;

    if (!link)
        goto out; /* No link detected */

    mac->get_link_status = false;

    /*
     * Check if there was DownShift, must be checked
     * immediately after link-up
     */
    igb_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) {
        ret_val = -E1000_ERR_CONFIG;
        goto out;
    }

    /*
     * 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.
     */
    igb_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 = igb_config_fc_after_link_up(hw);
    if (ret_val)
        hw_dbg("Error configuring flow control\n");

out:
    return ret_val;
}

s32 igb_setup_link(struct e1000_hw *hw)
{
    s32 ret_val = 0;

    /*
     * In the case of the phy reset being blocked, we already have a link.
     * We do not need to set it up again.
     */
    if (igb_check_reset_block(hw))
        goto out;

    /*
     * 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 = igb_set_default_fc(hw);
        if (ret_val)
            goto out;
    }

    /*
     * We want to save off the original Flow Control configuration just
     * in case we get disconnected and then reconnected into a different
     * hub or switch with different Flow Control capabilities.
     */
    hw->fc.current_mode = hw->fc.requested_mode;

    hw_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)
        goto out;

    /*
     * 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.
     */
    hw_dbg("Initializing the Flow Control address, type and timer regs\n");
    wr32(E1000_FCT, FLOW_CONTROL_TYPE);
    wr32(E1000_FCAH, FLOW_CONTROL_ADDRESS_HIGH);
    wr32(E1000_FCAL, FLOW_CONTROL_ADDRESS_LOW);

    wr32(E1000_FCTTV, hw->fc.pause_time);

    ret_val = igb_set_fc_watermarks(hw);

out:

    return ret_val;
}

void igb_config_collision_dist(struct e1000_hw *hw)
{
    u32 tctl;

    tctl = rd32(E1000_TCTL);

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

    wr32(E1000_TCTL, tctl);
    wrfl();
}

static s32 igb_set_fc_watermarks(struct e1000_hw *hw)
{
    s32 ret_val = 0;
    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;
    }
    wr32(E1000_FCRTL, fcrtl);
    wr32(E1000_FCRTH, fcrth);

    return ret_val;
}

static s32 igb_set_default_fc(struct e1000_hw *hw)
{
    s32 ret_val = 0;
    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 = hw->nvm.ops.read(hw, NVM_INIT_CONTROL2_REG, 1, &nvm_data);

    if (ret_val) {
        hw_dbg("NVM Read Error\n");
        goto out;
    }

    if ((nvm_data & NVM_WORD0F_PAUSE_MASK) == 0)
        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;

out:
    return ret_val;
}

s32 igb_force_mac_fc(struct e1000_hw *hw)
{
    u32 ctrl;
    s32 ret_val = 0;

    ctrl = rd32(E1000_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.
     */
    hw_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:
        hw_dbg("Flow control param set incorrectly\n");
        ret_val = -E1000_ERR_CONFIG;
        goto out;
    }

    wr32(E1000_CTRL, ctrl);

out:
    return ret_val;
}

s32 igb_config_fc_after_link_up(struct e1000_hw *hw)
{
    struct e1000_mac_info *mac = &hw->mac;
    s32 ret_val = 0;
    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_internal_serdes)
            ret_val = igb_force_mac_fc(hw);
    } else {
        if (hw->phy.media_type == e1000_media_type_copper)
            ret_val = igb_force_mac_fc(hw);
    }

    if (ret_val) {
        hw_dbg("Error forcing flow control settings\n");
        goto out;
    }

    /*
     * 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 = hw->phy.ops.read_reg(hw, PHY_STATUS,
                           &mii_status_reg);
        if (ret_val)
            goto out;
        ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS,
                           &mii_status_reg);
        if (ret_val)
            goto out;

        if (!(mii_status_reg & MII_SR_AUTONEG_COMPLETE)) {
            hw_dbg("Copper PHY and Auto Neg "
                 "has not completed.\n");
            goto out;
        }

        /*
         * 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 = hw->phy.ops.read_reg(hw, PHY_AUTONEG_ADV,
                        &mii_nway_adv_reg);
        if (ret_val)
            goto out;
        ret_val = hw->phy.ops.read_reg(hw, PHY_LP_ABILITY,
                        &mii_nway_lp_ability_reg);
        if (ret_val)
            goto out;

        /*
         * 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 & NWAY_AR_PAUSE) &&
            (mii_nway_lp_ability_reg & NWAY_LPAR_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;
                hw_dbg("Flow Control = FULL.\r\n");
            } else {
                hw->fc.current_mode = e1000_fc_rx_pause;
                hw_dbg("Flow Control = "
                       "RX PAUSE frames only.\r\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 & NWAY_AR_PAUSE) &&
              (mii_nway_adv_reg & NWAY_AR_ASM_DIR) &&
              (mii_nway_lp_ability_reg & NWAY_LPAR_PAUSE) &&
              (mii_nway_lp_ability_reg & NWAY_LPAR_ASM_DIR)) {
            hw->fc.current_mode = e1000_fc_tx_pause;
            hw_dbg("Flow Control = TX PAUSE frames only.\r\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 & NWAY_AR_PAUSE) &&
             (mii_nway_adv_reg & NWAY_AR_ASM_DIR) &&
             !(mii_nway_lp_ability_reg & NWAY_LPAR_PAUSE) &&
             (mii_nway_lp_ability_reg & NWAY_LPAR_ASM_DIR)) {
            hw->fc.current_mode = e1000_fc_rx_pause;
            hw_dbg("Flow Control = RX PAUSE frames only.\r\n");
        }
        /*
         * Per the IEEE spec, at this point flow control should be
         * disabled.  However, we want to consider that we could
         * be connected to a legacy switch that doesn't advertise
         * desired flow control, but can be forced on the link
         * partner.  So if we advertised no flow control, that is
         * what we will resolve to.  If we advertised some kind of
         * receive capability (Rx Pause Only or Full Flow Control)
         * and the link partner advertised none, we will configure
         * ourselves to enable Rx Flow Control only.  We can do
         * this safely for two reasons:  If the link partner really
         * didn't want flow control enabled, and we enable Rx, no
         * harm done since we won't be receiving any PAUSE frames
         * anyway.  If the intent on the link partner was to have
         * flow control enabled, then by us enabling RX only, we
         * can at least receive pause frames and process them.
         * This is a good idea because in most cases, since we are
         * predominantly a server NIC, more times than not we will
         * be asked to delay transmission of packets than asking
         * our link partner to pause transmission of frames.
         */
        else if ((hw->fc.requested_mode == e1000_fc_none ||
              hw->fc.requested_mode == e1000_fc_tx_pause) ||
             hw->fc.strict_ieee) {
            hw->fc.current_mode = e1000_fc_none;
            hw_dbg("Flow Control = NONE.\r\n");
        } else {
            hw->fc.current_mode = e1000_fc_rx_pause;
            hw_dbg("Flow Control = RX PAUSE frames only.\r\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 = hw->mac.ops.get_speed_and_duplex(hw, &speed, &duplex);
        if (ret_val) {
            hw_dbg("Error getting link speed and duplex\n");
            goto out;
        }

        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 = igb_force_mac_fc(hw);
        if (ret_val) {
            hw_dbg("Error forcing flow control settings\n");
            goto out;
        }
    }

out:
    return ret_val;
}

s32 igb_get_speed_and_duplex_copper(struct e1000_hw *hw, u16 *speed,
                      u16 *duplex)
{
    u32 status;

    status = rd32(E1000_STATUS);
    if (status & E1000_STATUS_SPEED_1000) {
        *speed = SPEED_1000;
        hw_dbg("1000 Mbs, ");
    } else if (status & E1000_STATUS_SPEED_100) {
        *speed = SPEED_100;
        hw_dbg("100 Mbs, ");
    } else {
        *speed = SPEED_10;
        hw_dbg("10 Mbs, ");
    }

    if (status & E1000_STATUS_FD) {
        *duplex = FULL_DUPLEX;
        hw_dbg("Full Duplex\n");
    } else {
        *duplex = HALF_DUPLEX;
        hw_dbg("Half Duplex\n");
    }

    return 0;
}

s32 igb_get_hw_semaphore(struct e1000_hw *hw)
{
    u32 swsm;
    s32 ret_val = 0;
    s32 timeout = hw->nvm.word_size + 1;
    s32 i = 0;

    /* Get the SW semaphore */
    while (i < timeout) {
        swsm = rd32(E1000_SWSM);
        if (!(swsm & E1000_SWSM_SMBI))
            break;

        udelay(50);
        i++;
    }

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

    /* Get the FW semaphore. */
    for (i = 0; i < timeout; i++) {
        swsm = rd32(E1000_SWSM);
        wr32(E1000_SWSM, swsm | E1000_SWSM_SWESMBI);

        /* Semaphore acquired if bit latched */
        if (rd32(E1000_SWSM) & E1000_SWSM_SWESMBI)
            break;

        udelay(50);
    }

    if (i == timeout) {
        /* Release semaphores */
        igb_put_hw_semaphore(hw);
        hw_dbg("Driver can't access the NVM\n");
        ret_val = -E1000_ERR_NVM;
        goto out;
    }

out:
    return ret_val;
}

void igb_put_hw_semaphore(struct e1000_hw *hw)
{
    u32 swsm;

    swsm = rd32(E1000_SWSM);

    swsm &= ~(E1000_SWSM_SMBI | E1000_SWSM_SWESMBI);

    wr32(E1000_SWSM, swsm);
}

s32 igb_get_auto_rd_done(struct e1000_hw *hw)
{
    s32 i = 0;
    s32 ret_val = 0;


    while (i < AUTO_READ_DONE_TIMEOUT) {
        if (rd32(E1000_EECD) & E1000_EECD_AUTO_RD)
            break;
        msleep(1);
        i++;
    }

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

out:
    return ret_val;
}

static s32 igb_valid_led_default(struct e1000_hw *hw, u16 *data)
{
    s32 ret_val;

    ret_val = hw->nvm.ops.read(hw, NVM_ID_LED_SETTINGS, 1, data);
    if (ret_val) {
        hw_dbg("NVM Read Error\n");
        goto out;
    }

    if (*data == ID_LED_RESERVED_0000 || *data == ID_LED_RESERVED_FFFF) {
        switch(hw->phy.media_type) {
        case e1000_media_type_internal_serdes:
            *data = ID_LED_DEFAULT_82575_SERDES;
            break;
        case e1000_media_type_copper:
        default:
            *data = ID_LED_DEFAULT;
            break;
        }
    }
out:
    return ret_val;
}

s32 igb_id_led_init(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 = igb_valid_led_default(hw, &data);
    if (ret_val)
        goto out;

    mac->ledctl_default = rd32(E1000_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;
        }
    }

out:
    return ret_val;
}

s32 igb_cleanup_led(struct e1000_hw *hw)
{
    wr32(E1000_LEDCTL, hw->mac.ledctl_default);
    return 0;
}

s32 igb_blink_led(struct e1000_hw *hw)
{
    u32 ledctl_blink = 0;
    u32 i;

    /*
     * set the blink bit for each LED that's "on" (0x0E)
     * in ledctl_mode2
     */
    ledctl_blink = hw->mac.ledctl_mode2;
    for (i = 0; i < 4; i++)
        if (((hw->mac.ledctl_mode2 >> (i * 8)) & 0xFF) ==
            E1000_LEDCTL_MODE_LED_ON)
            ledctl_blink |= (E1000_LEDCTL_LED0_BLINK <<
                     (i * 8));

    wr32(E1000_LEDCTL, ledctl_blink);

    return 0;
}

s32 igb_led_off(struct e1000_hw *hw)
{
    switch (hw->phy.media_type) {
    case e1000_media_type_copper:
        wr32(E1000_LEDCTL, hw->mac.ledctl_mode1);
        break;
    default:
        break;
    }

    return 0;
}

s32 igb_disable_pcie_master(struct e1000_hw *hw)
{
    u32 ctrl;
    s32 timeout = MASTER_DISABLE_TIMEOUT;
    s32 ret_val = 0;

    if (hw->bus.type != e1000_bus_type_pci_express)
        goto out;

    ctrl = rd32(E1000_CTRL);
    ctrl |= E1000_CTRL_GIO_MASTER_DISABLE;
    wr32(E1000_CTRL, ctrl);

    while (timeout) {
        if (!(rd32(E1000_STATUS) &
              E1000_STATUS_GIO_MASTER_ENABLE))
            break;
        udelay(100);
        timeout--;
    }

    if (!timeout) {
        hw_dbg("Master requests are pending.\n");
        ret_val = -E1000_ERR_MASTER_REQUESTS_PENDING;
        goto out;
    }

out:
    return ret_val;
}

s32 igb_validate_mdi_setting(struct e1000_hw *hw)
{
    s32 ret_val = 0;

    if (!hw->mac.autoneg && (hw->phy.mdix == 0 || hw->phy.mdix == 3)) {
        hw_dbg("Invalid MDI setting detected\n");
        hw->phy.mdix = 1;
        ret_val = -E1000_ERR_CONFIG;
        goto out;
    }

out:
    return ret_val;
}

s32 igb_write_8bit_ctrl_reg(struct e1000_hw *hw, u32 reg,
                  u32 offset, u8 data)
{
    u32 i, regvalue = 0;
    s32 ret_val = 0;

    /* Set up the address and data */
    regvalue = ((u32)data) | (offset << E1000_GEN_CTL_ADDRESS_SHIFT);
    wr32(reg, regvalue);

    /* Poll the ready bit to see if the MDI read completed */
    for (i = 0; i < E1000_GEN_POLL_TIMEOUT; i++) {
        udelay(5);
        regvalue = rd32(reg);
        if (regvalue & E1000_GEN_CTL_READY)
            break;
    }
    if (!(regvalue & E1000_GEN_CTL_READY)) {
        hw_dbg("Reg %08x did not indicate ready\n", reg);
        ret_val = -E1000_ERR_PHY;
        goto out;
    }

out:
    return ret_val;
}

bool igb_enable_mng_pass_thru(struct e1000_hw *hw)
{
    u32 manc;
    u32 fwsm, factps;
    bool ret_val = false;

    if (!hw->mac.asf_firmware_present)
        goto out;

    manc = rd32(E1000_MANC);

    if (!(manc & E1000_MANC_RCV_TCO_EN))
        goto out;

    if (hw->mac.arc_subsystem_valid) {
        fwsm = rd32(E1000_FWSM);
        factps = rd32(E1000_FACTPS);

        if (!(factps & E1000_FACTPS_MNGCG) &&
            ((fwsm & E1000_FWSM_MODE_MASK) ==
             (e1000_mng_mode_pt << E1000_FWSM_MODE_SHIFT))) {
            ret_val = true;
            goto out;
        }
    } else {
        if ((manc & E1000_MANC_SMBUS_EN) &&
            !(manc & E1000_MANC_ASF_EN)) {
            ret_val = true;
            goto out;
        }
    }

out:
    return ret_val;
}