ixl(4): Add tunable to override Flow Control settings

Add flow_control to hw.ixl tunables tree to let override
initial flow control configuration for all interfaces.
Keep using configuration set by NVM by default.

Reviewed by:	erj@, gallatin@
Tested by:	gowtham.kumar.ks_intel.com
MFC after:	1 week
Sponsored by:	Intel Corporation
Differential Revision:	https://reviews.freebsd.org/D29338

3 files changed, 43 insertions, 18 deletions

diff --git a/sys/dev/ixl/if_ixl.c b/sys/dev/ixl/if_ixl.c
index c700af889cf1..3b49da5d76b9 100644
--- a/sys/dev/ixl/if_ixl.c
+++ b/sys/dev/ixl/if_ixl.c
@@ -304,6 +304,10 @@ TUNABLE_INT("hw.ixl.tx_itr", &ixl_tx_itr);
 SYSCTL_INT(_hw_ixl, OID_AUTO, tx_itr, CTLFLAG_RDTUN,
     &ixl_tx_itr, 0, "TX Interrupt Rate");
 
+static int ixl_flow_control = -1;
+SYSCTL_INT(_hw_ixl, OID_AUTO, flow_control, CTLFLAG_RDTUN,
+    &ixl_flow_control, 0, "Initial Flow Control setting");
+
 #ifdef IXL_IW
 int ixl_enable_iwarp = 0;
 TUNABLE_INT("hw.ixl.enable_iwarp", &ixl_enable_iwarp);
@@ -1892,5 +1896,20 @@ ixl_save_pf_tunables(struct ixl_pf *pf)
 		pf->rx_itr = IXL_ITR_8K;
 	} else
 		pf->rx_itr = ixl_rx_itr;
+
+	pf->fc = -1;
+	if (ixl_flow_control != -1) {
+		if (ixl_flow_control < 0 || ixl_flow_control > 3) {
+			device_printf(dev,
+			    "Invalid flow_control value of %d set!\n",
+			    ixl_flow_control);
+			device_printf(dev,
+			    "flow_control must be between %d and %d, "
+			    "inclusive\n", 0, 3);
+			device_printf(dev,
+			    "Using default configuration instead\n");
+		} else
+			pf->fc = ixl_flow_control;
+	}
 }
 
diff --git a/sys/dev/ixl/ixl_pf_iflib.c b/sys/dev/ixl/ixl_pf_iflib.c
index 23d9f30299a9..68a174889c41 100644
--- a/sys/dev/ixl/ixl_pf_iflib.c
+++ b/sys/dev/ixl/ixl_pf_iflib.c
@@ -1094,7 +1094,7 @@ ixl_sysctl_set_flowcntl(SYSCTL_HANDLER_ARGS)
 	aq_error = i40e_set_fc(hw, &fc_aq_err, TRUE);
 	if (aq_error) {
 		device_printf(dev,
-		    "%s: Error setting new fc mode %d; fc_err %#x\n",
+		    "%s: Error setting Flow Control mode %d; fc_err %#x\n",
 		    __func__, aq_error, fc_aq_err);
 		return (EIO);
 	}
diff --git a/sys/dev/ixl/ixl_pf_main.c b/sys/dev/ixl/ixl_pf_main.c
index b546701608f1..896da955843a 100644
--- a/sys/dev/ixl/ixl_pf_main.c
+++ b/sys/dev/ixl/ixl_pf_main.c
@@ -3169,27 +3169,28 @@ ixl_set_link(struct ixl_pf *pf, bool enable)
 	config.phy_type = 0;
 	config.phy_type_ext = 0;
 
+	config.abilities &= ~(I40E_AQ_PHY_FLAG_PAUSE_TX |
+			I40E_AQ_PHY_FLAG_PAUSE_RX);
+
+	switch (pf->fc) {
+	case I40E_FC_FULL:
+		config.abilities |= I40E_AQ_PHY_FLAG_PAUSE_TX |
+			I40E_AQ_PHY_FLAG_PAUSE_RX;
+		break;
+	case I40E_FC_RX_PAUSE:
+		config.abilities |= I40E_AQ_PHY_FLAG_PAUSE_RX;
+		break;
+	case I40E_FC_TX_PAUSE:
+		config.abilities |= I40E_AQ_PHY_FLAG_PAUSE_TX;
+		break;
+	default:
+		break;
+	}
+
 	if (enable) {
 		config.phy_type = phy_type;
 		config.phy_type_ext = phy_type_ext;
 
-		config.abilities &= ~(I40E_AQ_PHY_FLAG_PAUSE_TX |
-		    I40E_AQ_PHY_FLAG_PAUSE_RX);
-
-		switch (pf->fc) {
-		case I40E_FC_FULL:
-			config.abilities |= I40E_AQ_PHY_FLAG_PAUSE_TX |
-			    I40E_AQ_PHY_FLAG_PAUSE_RX;
-			break;
-		case I40E_FC_RX_PAUSE:
-			config.abilities |= I40E_AQ_PHY_FLAG_PAUSE_RX;
-			break;
-		case I40E_FC_TX_PAUSE:
-			config.abilities |= I40E_AQ_PHY_FLAG_PAUSE_TX;
-			break;
-		default:
-			break;
-		}
 	}
 
 	aq_error = i40e_aq_set_phy_config(hw, &config, NULL);
@@ -4594,6 +4595,11 @@ ixl_attach_get_link_status(struct ixl_pf *pf)
 	/* Determine link state */
 	hw->phy.get_link_info = TRUE;
 	i40e_get_link_status(hw, &pf->link_up);
+
+	/* Flow Control mode not set by user, read current FW settings */
+	if (pf->fc == -1)
+		pf->fc = hw->fc.current_mode;
+
 	return (0);
 }