net/txgbe: support FC auto negotiation

Add flow control negotiation with link partner.

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

diff --git a/drivers/net/txgbe/base/txgbe_hw.c b/drivers/net/txgbe/base/txgbe_hw.c
index 7a6c309..15ab82b 100644 (file)
--- a/drivers/net/txgbe/base/txgbe_hw.c
+++ b/drivers/net/txgbe/base/txgbe_hw.c
@@ -1016,6 +1016,205 @@ out:
        return err;
 }
 
+/**
+ *  txgbe_negotiate_fc - Negotiate flow control
+ *  @hw: pointer to hardware structure
+ *  @adv_reg: flow control advertised settings
+ *  @lp_reg: link partner's flow control settings
+ *  @adv_sym: symmetric pause bit in advertisement
+ *  @adv_asm: asymmetric pause bit in advertisement
+ *  @lp_sym: symmetric pause bit in link partner advertisement
+ *  @lp_asm: asymmetric pause bit in link partner advertisement
+ *
+ *  Find the intersection between advertised settings and link partner's
+ *  advertised settings
+ **/
+s32 txgbe_negotiate_fc(struct txgbe_hw *hw, u32 adv_reg, u32 lp_reg,
+                      u32 adv_sym, u32 adv_asm, u32 lp_sym, u32 lp_asm)
+{
+       if ((!(adv_reg)) ||  (!(lp_reg))) {
+               DEBUGOUT("Local or link partner's advertised flow control "
+                             "settings are NULL. Local: %x, link partner: %x\n",
+                             adv_reg, lp_reg);
+               return TXGBE_ERR_FC_NOT_NEGOTIATED;
+       }
+
+       if ((adv_reg & adv_sym) && (lp_reg & lp_sym)) {
+               /*
+                * 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 == txgbe_fc_full) {
+                       hw->fc.current_mode = txgbe_fc_full;
+                       DEBUGOUT("Flow Control = FULL.\n");
+               } else {
+                       hw->fc.current_mode = txgbe_fc_rx_pause;
+                       DEBUGOUT("Flow Control=RX PAUSE frames only\n");
+               }
+       } else if (!(adv_reg & adv_sym) && (adv_reg & adv_asm) &&
+                  (lp_reg & lp_sym) && (lp_reg & lp_asm)) {
+               hw->fc.current_mode = txgbe_fc_tx_pause;
+               DEBUGOUT("Flow Control = TX PAUSE frames only.\n");
+       } else if ((adv_reg & adv_sym) && (adv_reg & adv_asm) &&
+                  !(lp_reg & lp_sym) && (lp_reg & lp_asm)) {
+               hw->fc.current_mode = txgbe_fc_rx_pause;
+               DEBUGOUT("Flow Control = RX PAUSE frames only.\n");
+       } else {
+               hw->fc.current_mode = txgbe_fc_none;
+               DEBUGOUT("Flow Control = NONE.\n");
+       }
+       return 0;
+}
+
+/**
+ *  txgbe_fc_autoneg_fiber - Enable flow control on 1 gig fiber
+ *  @hw: pointer to hardware structure
+ *
+ *  Enable flow control according on 1 gig fiber.
+ **/
+STATIC s32 txgbe_fc_autoneg_fiber(struct txgbe_hw *hw)
+{
+       u32 pcs_anadv_reg, pcs_lpab_reg;
+       s32 err = TXGBE_ERR_FC_NOT_NEGOTIATED;
+
+       /*
+        * On multispeed fiber at 1g, bail out if
+        * - link is up but AN did not complete, or if
+        * - link is up and AN completed but timed out
+        */
+
+       pcs_anadv_reg = rd32_epcs(hw, SR_MII_MMD_AN_ADV);
+       pcs_lpab_reg = rd32_epcs(hw, SR_MII_MMD_LP_BABL);
+
+       err =  txgbe_negotiate_fc(hw, pcs_anadv_reg,
+                                     pcs_lpab_reg,
+                                     SR_MII_MMD_AN_ADV_PAUSE_SYM,
+                                     SR_MII_MMD_AN_ADV_PAUSE_ASM,
+                                     SR_MII_MMD_AN_ADV_PAUSE_SYM,
+                                     SR_MII_MMD_AN_ADV_PAUSE_ASM);
+
+       return err;
+}
+
+/**
+ *  txgbe_fc_autoneg_backplane - Enable flow control IEEE clause 37
+ *  @hw: pointer to hardware structure
+ *
+ *  Enable flow control according to IEEE clause 37.
+ **/
+STATIC s32 txgbe_fc_autoneg_backplane(struct txgbe_hw *hw)
+{
+       u32 anlp1_reg, autoc_reg;
+       s32 err = TXGBE_ERR_FC_NOT_NEGOTIATED;
+
+       /*
+        * Read the 10g AN autoc and LP ability registers and resolve
+        * local flow control settings accordingly
+        */
+       autoc_reg = rd32_epcs(hw, SR_AN_MMD_ADV_REG1);
+       anlp1_reg = rd32_epcs(hw, SR_AN_MMD_LP_ABL1);
+
+       err = txgbe_negotiate_fc(hw, autoc_reg,
+               anlp1_reg,
+               SR_AN_MMD_ADV_REG1_PAUSE_SYM,
+               SR_AN_MMD_ADV_REG1_PAUSE_ASM,
+               SR_AN_MMD_ADV_REG1_PAUSE_SYM,
+               SR_AN_MMD_ADV_REG1_PAUSE_ASM);
+
+       return err;
+}
+
+/**
+ *  txgbe_fc_autoneg_copper - Enable flow control IEEE clause 37
+ *  @hw: pointer to hardware structure
+ *
+ *  Enable flow control according to IEEE clause 37.
+ **/
+STATIC s32 txgbe_fc_autoneg_copper(struct txgbe_hw *hw)
+{
+       u16 technology_ability_reg = 0;
+       u16 lp_technology_ability_reg = 0;
+
+       hw->phy.read_reg(hw, TXGBE_MD_AUTO_NEG_ADVT,
+                            TXGBE_MD_DEV_AUTO_NEG,
+                            &technology_ability_reg);
+       hw->phy.read_reg(hw, TXGBE_MD_AUTO_NEG_LP,
+                            TXGBE_MD_DEV_AUTO_NEG,
+                            &lp_technology_ability_reg);
+
+       return txgbe_negotiate_fc(hw, (u32)technology_ability_reg,
+                                 (u32)lp_technology_ability_reg,
+                                 TXGBE_TAF_SYM_PAUSE, TXGBE_TAF_ASM_PAUSE,
+                                 TXGBE_TAF_SYM_PAUSE, TXGBE_TAF_ASM_PAUSE);
+}
+
+/**
+ *  txgbe_fc_autoneg - Configure flow control
+ *  @hw: pointer to hardware structure
+ *
+ *  Compares our advertised flow control capabilities to those advertised by
+ *  our link partner, and determines the proper flow control mode to use.
+ **/
+void txgbe_fc_autoneg(struct txgbe_hw *hw)
+{
+       s32 err = TXGBE_ERR_FC_NOT_NEGOTIATED;
+       u32 speed;
+       bool link_up;
+
+       DEBUGFUNC("txgbe_fc_autoneg");
+
+       /*
+        * AN should have completed when the cable was plugged in.
+        * Look for reasons to bail out.  Bail out if:
+        * - FC autoneg is disabled, or if
+        * - link is not up.
+        */
+       if (hw->fc.disable_fc_autoneg) {
+               DEBUGOUT("Flow control autoneg is disabled");
+               goto out;
+       }
+
+       hw->mac.check_link(hw, &speed, &link_up, false);
+       if (!link_up) {
+               DEBUGOUT("The link is down");
+               goto out;
+       }
+
+       switch (hw->phy.media_type) {
+       /* Autoneg flow control on fiber adapters */
+       case txgbe_media_type_fiber_qsfp:
+       case txgbe_media_type_fiber:
+               if (speed == TXGBE_LINK_SPEED_1GB_FULL)
+                       err = txgbe_fc_autoneg_fiber(hw);
+               break;
+
+       /* Autoneg flow control on backplane adapters */
+       case txgbe_media_type_backplane:
+               err = txgbe_fc_autoneg_backplane(hw);
+               break;
+
+       /* Autoneg flow control on copper adapters */
+       case txgbe_media_type_copper:
+               if (txgbe_device_supports_autoneg_fc(hw))
+                       err = txgbe_fc_autoneg_copper(hw);
+               break;
+
+       default:
+               break;
+       }
+
+out:
+       if (err == 0) {
+               hw->fc.fc_was_autonegged = true;
+       } else {
+               hw->fc.fc_was_autonegged = false;
+               hw->fc.current_mode = hw->fc.requested_mode;
+       }
+}
+
 /**
  *  txgbe_acquire_swfw_sync - Acquire SWFW semaphore
  *  @hw: pointer to hardware structure
@@ -2588,6 +2787,7 @@ s32 txgbe_init_ops_pf(struct txgbe_hw *hw)
        /* Flow Control */
        mac->fc_enable = txgbe_fc_enable;
        mac->setup_fc = txgbe_setup_fc;
+       mac->fc_autoneg = txgbe_fc_autoneg;
 
        /* Link */
        mac->get_link_capabilities = txgbe_get_link_capabilities_raptor;

diff --git a/drivers/net/txgbe/base/txgbe_hw.h b/drivers/net/txgbe/base/txgbe_hw.h
index 1e1cbb2..02369d6 100644 (file)
--- a/drivers/net/txgbe/base/txgbe_hw.h
+++ b/drivers/net/txgbe/base/txgbe_hw.h
@@ -30,6 +30,7 @@ s32 txgbe_enable_sec_tx_path(struct txgbe_hw *hw);
 
 s32 txgbe_fc_enable(struct txgbe_hw *hw);
 bool txgbe_device_supports_autoneg_fc(struct txgbe_hw *hw);
+void txgbe_fc_autoneg(struct txgbe_hw *hw);
 s32 txgbe_setup_fc(struct txgbe_hw *hw);
 
 s32 txgbe_validate_mac_addr(u8 *mac_addr);
@@ -76,6 +77,8 @@ s32 txgbe_setup_mac_link_multispeed_fiber(struct txgbe_hw *hw,
                                          u32 speed,
                                          bool autoneg_wait_to_complete);
 void txgbe_set_mta(struct txgbe_hw *hw, u8 *mc_addr);
+s32 txgbe_negotiate_fc(struct txgbe_hw *hw, u32 adv_reg, u32 lp_reg,
+                       u32 adv_sym, u32 adv_asm, u32 lp_sym, u32 lp_asm);
 s32 txgbe_init_shared_code(struct txgbe_hw *hw);
 s32 txgbe_set_mac_type(struct txgbe_hw *hw);
 s32 txgbe_init_ops_pf(struct txgbe_hw *hw);