e1000_hw.c

COPE the first practical network coding scheme which is developped on click

             *-------|---------|-------|---------|--------------------
             *   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->original_fc == e1000_fc_full) {
                    hw->fc = e1000_fc_full;
                    DEBUGOUT("Flow Control = FULL.\r\n");
                } else {
                    hw->fc = e1000_fc_rx_pause;
                    DEBUGOUT("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 = e1000_fc_tx_pause;
                DEBUGOUT("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 = e1000_fc_rx_pause;
                DEBUGOUT("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->original_fc == e1000_fc_none ||
                    hw->original_fc == e1000_fc_tx_pause) {
                hw->fc = e1000_fc_none;
                DEBUGOUT("Flow Control = NONE.\r\n");
            } else {
                hw->fc = e1000_fc_rx_pause;
                DEBUGOUT("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.
             */
            e1000_get_speed_and_duplex(hw, &speed, &duplex);

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

            /* Now we call a subroutine to actually force the MAC
             * controller to use the correct flow control settings.
             */
            ret_val = e1000_force_mac_fc(hw);
            if(ret_val < 0) {
                DEBUGOUT("Error forcing flow control settings\n");
                return ret_val;
             }
        } else {
            DEBUGOUT("Copper PHY and Auto Neg has not completed.\r\n");
        }
    }
    return 0;
}

/******************************************************************************
 * Checks to see if the link status of the hardware has changed.
 *
 * hw - Struct containing variables accessed by shared code
 *
 * Called by any function that needs to check the link status of the adapter.
 *****************************************************************************/
int32_t
e1000_check_for_link(struct e1000_hw *hw)
{
    uint32_t rxcw;
    uint32_t ctrl;
    uint32_t status;
    uint32_t rctl;
    uint32_t signal;
    int32_t ret_val;
    uint16_t phy_data;
    uint16_t lp_capability;

    DEBUGFUNC("e1000_check_for_link");
    
    /* On adapters with a MAC newer that 82544, SW Defineable pin 1 will be 
     * set when the optics detect a signal. On older adapters, it will be 
     * cleared when there is a signal
     */
    if(hw->mac_type > e1000_82544) signal = E1000_CTRL_SWDPIN1;
    else signal = 0;

    ctrl = E1000_READ_REG(hw, CTRL);
    status = E1000_READ_REG(hw, STATUS);
    rxcw = E1000_READ_REG(hw, RXCW);

    /* If we have a copper PHY then 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 will be set if we
     * receive a Link Status Change interrupt or we have Rx Sequence
     * Errors.
     */
    if((hw->media_type == e1000_media_type_copper) && hw->get_link_status) {
        /* 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.
         * Read the register twice since the link bit is sticky.
         */
        if(e1000_read_phy_reg(hw, PHY_STATUS, &phy_data) < 0) {
            DEBUGOUT("PHY Read Error\n");
            return -E1000_ERR_PHY;
        }
        if(e1000_read_phy_reg(hw, PHY_STATUS, &phy_data) < 0) {
            DEBUGOUT("PHY Read Error\n");
            return -E1000_ERR_PHY;
        }

        if(phy_data & MII_SR_LINK_STATUS) {
            hw->get_link_status = FALSE;
        } else {
            /* No link detected */
            return 0;
        }

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

        /* We have a M88E1000 PHY and Auto-Neg is enabled.  If we
         * have Si on board that is 82544 or newer, Auto
         * Speed Detection takes care of MAC speed/duplex
         * configuration.  So we only need to configure Collision
         * Distance in the MAC.  Otherwise, we need to force
         * speed/duplex on the MAC to the current PHY speed/duplex
         * settings.
         */
        if(hw->mac_type >= e1000_82544)
            e1000_config_collision_dist(hw);
        else {
            ret_val = e1000_config_mac_to_phy(hw);
            if(ret_val < 0) {
                DEBUGOUT("Error configuring MAC to PHY settings\n");
                return ret_val;
            }
        }

        /* 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 = e1000_config_fc_after_link_up(hw);
        if(ret_val < 0) {
            DEBUGOUT("Error configuring flow control\n");
            return ret_val;
        }

        /* At this point we know that we are on copper and we have
         * auto-negotiated link.  These are conditions for checking the link
         * parter capability register.  We use the link partner capability to
         * determine if TBI Compatibility needs to be turned on or off.  If
         * the link partner advertises any speed in addition to Gigabit, then
         * we assume that they are GMII-based, and TBI compatibility is not
         * needed. If no other speeds are advertised, we assume the link
         * partner is TBI-based, and we turn on TBI Compatibility.
         */
        if(hw->tbi_compatibility_en) {
            if(e1000_read_phy_reg(hw, PHY_LP_ABILITY, &lp_capability) < 0) {
                DEBUGOUT("PHY Read Error\n");
                return -E1000_ERR_PHY;
            }
            if(lp_capability & (NWAY_LPAR_10T_HD_CAPS |
                                NWAY_LPAR_10T_FD_CAPS |
                                NWAY_LPAR_100TX_HD_CAPS |
                                NWAY_LPAR_100TX_FD_CAPS |
                                NWAY_LPAR_100T4_CAPS)) {
                /* If our link partner advertises anything in addition to 
                 * gigabit, we do not need to enable TBI compatibility.
                 */
                if(hw->tbi_compatibility_on) {
                    /* If we previously were in the mode, turn it off. */
                    rctl = E1000_READ_REG(hw, RCTL);
                    rctl &= ~E1000_RCTL_SBP;
                    E1000_WRITE_REG(hw, RCTL, rctl);
                    hw->tbi_compatibility_on = FALSE;
                }
            } else {
                /* If TBI compatibility is was previously off, turn it on. For
                 * compatibility with a TBI link partner, we will store bad
                 * packets. Some frames have an additional byte on the end and
                 * will look like CRC errors to to the hardware.
                 */
                if(!hw->tbi_compatibility_on) {
                    hw->tbi_compatibility_on = TRUE;
                    rctl = E1000_READ_REG(hw, RCTL);
                    rctl |= E1000_RCTL_SBP;
                    E1000_WRITE_REG(hw, RCTL, rctl);
                }
            }
        }
    }
    /* 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.
     */
    else if((hw->media_type == e1000_media_type_fiber) &&
            (!(status & E1000_STATUS_LU)) &&
            ((ctrl & E1000_CTRL_SWDPIN1) == signal) &&
            (!(rxcw & E1000_RXCW_C))) {
        if(hw->autoneg_failed == 0) {
            hw->autoneg_failed = 1;
            return 0;
        }
        DEBUGOUT("NOT RXing /C/, disable AutoNeg and force link.\r\n");

        /* Disable auto-negotiation in the TXCW register */
        E1000_WRITE_REG(hw, TXCW, (hw->txcw & ~E1000_TXCW_ANE));

        /* Force link-up and also force full-duplex. */
        ctrl = E1000_READ_REG(hw, CTRL);
        ctrl |= (E1000_CTRL_SLU | E1000_CTRL_FD);
        E1000_WRITE_REG(hw, CTRL, ctrl);

        /* Configure Flow Control after forcing link up. */
        ret_val = e1000_config_fc_after_link_up(hw);
        if(ret_val < 0) {
            DEBUGOUT("Error configuring flow control\n");
            return ret_val;
        }
    }
    /* 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.
     */
    else if((hw->media_type == e1000_media_type_fiber) &&
              (ctrl & E1000_CTRL_SLU) &&
              (rxcw & E1000_RXCW_C)) {
        DEBUGOUT("RXing /C/, enable AutoNeg and stop forcing link.\r\n");
        E1000_WRITE_REG(hw, TXCW, hw->txcw);
        E1000_WRITE_REG(hw, CTRL, (ctrl & ~E1000_CTRL_SLU));
    }
    return 0;
}

/******************************************************************************
 * Detects the current speed and duplex settings of the hardware.
 *
 * hw - Struct containing variables accessed by shared code
 * speed - Speed of the connection
 * duplex - Duplex setting of the connection
 *****************************************************************************/
void
e1000_get_speed_and_duplex(struct e1000_hw *hw,
                           uint16_t *speed,
                           uint16_t *duplex)
{
    uint32_t status;

    DEBUGFUNC("e1000_get_speed_and_duplex");

    if(hw->mac_type >= e1000_82543) {
        status = E1000_READ_REG(hw, STATUS);
        if(status & E1000_STATUS_SPEED_1000) {
            *speed = SPEED_1000;
            DEBUGOUT("1000 Mbs, ");
        } else if(status & E1000_STATUS_SPEED_100) {
            *speed = SPEED_100;
            DEBUGOUT("100 Mbs, ");
        } else {
            *speed = SPEED_10;
            DEBUGOUT("10 Mbs, ");
        }

        if(status & E1000_STATUS_FD) {
            *duplex = FULL_DUPLEX;
            DEBUGOUT("Full Duplex\r\n");
        } else {
            *duplex = HALF_DUPLEX;
            DEBUGOUT(" Half Duplex\r\n");
        }
    } else {
        DEBUGOUT("1000 Mbs, Full Duplex\r\n");
        *speed = SPEED_1000;
        *duplex = FULL_DUPLEX;
    }
}

/******************************************************************************
* Blocks until autoneg completes or times out (~4.5 seconds)
*
* hw - Struct containing variables accessed by shared code
******************************************************************************/
int32_t
e1000_wait_autoneg(struct e