igc: Add setup link functionality

Add link establishment methods
Add auto negotiation methods
Add read MAC address method

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 271 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/igc/igc_mac.c b/drivers/net/ethernet/intel/igc/igc_mac.c
index fce7f7f5aa46..f7683d3ae47c 100644
--- a/drivers/net/ethernet/intel/igc/igc_mac.c
+++ b/drivers/net/ethernet/intel/igc/igc_mac.c
@@ -92,6 +92,8 @@ s32 igc_setup_link(struct igc_hw *hw)
 	/* In the case of the phy reset being blocked, we already have a link.
 	 * We do not need to set it up again.
 	 */
+	if (igc_check_reset_block(hw))
+		goto out;
 
 	/* If requested flow control is set to default, set flow control
 	 * based on the EEPROM flow control settings.
@@ -142,10 +144,74 @@ out:
  */
 static s32 igc_set_default_fc(struct igc_hw *hw)
 {
+	hw->fc.requested_mode = igc_fc_full;
 	return 0;
 }
 
 /**
+ * igc_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 igc_force_mac_fc(struct igc_hw *hw)
+{
+	s32 ret_val = 0;
+	u32 ctrl;
+
+	ctrl = rd32(IGC_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 igc_fc_none:
+		ctrl &= (~(IGC_CTRL_TFCE | IGC_CTRL_RFCE));
+		break;
+	case igc_fc_rx_pause:
+		ctrl &= (~IGC_CTRL_TFCE);
+		ctrl |= IGC_CTRL_RFCE;
+		break;
+	case igc_fc_tx_pause:
+		ctrl &= (~IGC_CTRL_RFCE);
+		ctrl |= IGC_CTRL_TFCE;
+		break;
+	case igc_fc_full:
+		ctrl |= (IGC_CTRL_TFCE | IGC_CTRL_RFCE);
+		break;
+	default:
+		hw_dbg("Flow control param set incorrectly\n");
+		ret_val = -IGC_ERR_CONFIG;
+		goto out;
+	}
+
+	wr32(IGC_CTRL, ctrl);
+
+out:
+	return ret_val;
+}
+
+/**
  * igc_set_fc_watermarks - Set flow control high/low watermarks
  * @hw: pointer to the HW structure
  *
@@ -371,6 +437,7 @@ s32 igc_check_for_copper_link(struct igc_hw *hw)
 	 * settings because we may have had to re-autoneg with a
 	 * different link partner.
 	 */
+	ret_val = igc_config_fc_after_link_up(hw);
 	if (ret_val)
 		hw_dbg("Error configuring flow control\n");
 
@@ -400,6 +467,210 @@ void igc_config_collision_dist(struct igc_hw *hw)
 }
 
 /**
+ * igc_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 igc_config_fc_after_link_up(struct igc_hw *hw)
+{
+	u16 mii_status_reg, mii_nway_adv_reg, mii_nway_lp_ability_reg;
+	struct igc_mac_info *mac = &hw->mac;
+	u16 speed, duplex;
+	s32 ret_val = 0;
+
+	/* 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 == igc_media_type_copper)
+			ret_val = igc_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 == igc_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    | igc_fc_none
+		 *   0   |    1    |   0   |   DC    | igc_fc_none
+		 *   0   |    1    |   1   |    0    | igc_fc_none
+		 *   0   |    1    |   1   |    1    | igc_fc_tx_pause
+		 *   1   |    0    |   0   |   DC    | igc_fc_none
+		 *   1   |   DC    |   1   |   DC    | igc_fc_full
+		 *   1   |    1    |   0   |    0    | igc_fc_none
+		 *   1   |    1    |   0   |    1    | igc_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    | IGC_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 == igc_fc_full) {
+				hw->fc.current_mode = igc_fc_full;
+				hw_dbg("Flow Control = FULL.\n");
+			} else {
+				hw->fc.current_mode = igc_fc_rx_pause;
+				hw_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    | igc_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 = igc_fc_tx_pause;
+			hw_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    | igc_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 = igc_fc_rx_pause;
+			hw_dbg("Flow Control = RX PAUSE frames only.\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 == igc_fc_none) ||
+			 (hw->fc.requested_mode == igc_fc_tx_pause) ||
+			 (hw->fc.strict_ieee)) {
+			hw->fc.current_mode = igc_fc_none;
+			hw_dbg("Flow Control = NONE.\n");
+		} else {
+			hw->fc.current_mode = igc_fc_rx_pause;
+			hw_dbg("Flow Control = RX PAUSE frames only.\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 = igc_fc_none;
+
+		/* Now we call a subroutine to actually force the MAC
+		 * controller to use the correct flow control settings.
+		 */
+		ret_val = igc_force_mac_fc(hw);
+		if (ret_val) {
+			hw_dbg("Error forcing flow control settings\n");
+			goto out;
+		}
+	}
+
+out:
+	return 0;
+}
+
+/**
  * igc_get_auto_rd_done - Check for auto read completion
  * @hw: pointer to the HW structure
  *