lib.c

grub源码分析文档

		ew32(CTRL, ctrl);

		/* Configure Flow Control after forcing link up. */
		ret_val = e1000e_config_fc_after_link_up(hw);
		if (ret_val) {
			hw_dbg(hw, "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.
		 */
		hw_dbg(hw, "RXing /C/, enable AutoNeg and stop forcing link.\n");
		ew32(TXCW, mac->txcw);
		ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));

		mac->serdes_has_link = 1;
	}

	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 == 0) {
			mac->autoneg_failed = 1;
			return 0;
		}
		hw_dbg(hw, "NOT RXing /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) {
			hw_dbg(hw, "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.
		 */
		hw_dbg(hw, "RXing /C/, enable AutoNeg and stop forcing link.\n");
		ew32(TXCW, mac->txcw);
		ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));

		mac->serdes_has_link = 1;
	} 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. */
		udelay(10);
		if (E1000_RXCW_SYNCH & er32(RXCW)) {
			if (!(rxcw & E1000_RXCW_IV)) {
				mac->serdes_has_link = 1;
				hw_dbg(hw, "SERDES: Link is up.\n");
			}
		} else {
			mac->serdes_has_link = 0;
			hw_dbg(hw, "SERDES: Link is down.\n");
		}
	}

	if (E1000_TXCW_ANE & er32(TXCW)) {
		status = er32(STATUS);
		mac->serdes_has_link = (status & E1000_STATUS_LU);
	}

	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) {
		hw_dbg(hw, "NVM Read Error\n");
		return ret_val;
	}

	if ((nvm_data & NVM_WORD0F_PAUSE_MASK) == 0)
		hw->fc.type = e1000_fc_none;
	else if ((nvm_data & NVM_WORD0F_PAUSE_MASK) ==
		 NVM_WORD0F_ASM_DIR)
		hw->fc.type = e1000_fc_tx_pause;
	else
		hw->fc.type = e1000_fc_full;

	return 0;
}

/**
 *  e1000e_setup_link - 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(struct e1000_hw *hw)
{
	struct e1000_mac_info *mac = &hw->mac;
	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 (e1000_check_reset_block(hw))
		return 0;

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

	/*
	 * 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.original_type = hw->fc.type;

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

	/* Call the necessary media_type subroutine to configure the link. */
	ret_val = 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.
	 */
	hw_dbg(hw, "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.type) {
	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:
		hw_dbg(hw, "Flow control param set incorrectly\n");
		return -E1000_ERR_CONFIG;
		break;
	}

	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++) {
		msleep(10);
		status = er32(STATUS);
		if (status & E1000_STATUS_LU)
			break;
	}
	if (i == FIBER_LINK_UP_LIMIT) {
		hw_dbg(hw, "Never got a valid link from auto-neg!!!\n");
		mac->autoneg_failed = 1;
		/*
		 * 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) {
			hw_dbg(hw, "Error while checking for link\n");
			return ret_val;
		}
		mac->autoneg_failed = 0;
	} else {
		mac->autoneg_failed = 0;
		hw_dbg(hw, "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;

	e1000e_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.
	 */
	hw_dbg(hw, "Auto-negotiation enabled\n");

	ew32(CTRL, ctrl);
	e1e_flush();
	msleep(1);

	/*
	 * 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 {
		hw_dbg(hw, "No signal detected\n");
	}

	return 0;
}

/**
 *  e1000e_config_collision_dist - Configure collision distance
 *  @hw: pointer to the HW structure
 *
 *  Configures the collision distance to the default value and is used
 *  during link setup. Currently no func pointer exists and all
 *  implementations are handled in the generic version of this function.
 **/
void e1000e_config_collision_dist(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.type & 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;
		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.type" 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, "hw->fc.type = %u\n", hw->fc.type);

	switch (hw->fc.type) {
	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;