i40e: Refactor VF BW rate limiting

This patch refactors the BW rate limiting for Tx traffic
on the VF to be reused in the next patch for rate limiting Tx
traffic for the VSIs on the PF as well.

Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -128,6 +128,10 @@
 /* default to trying for four seconds */
 #define I40E_TRY_LINK_TIMEOUT	(4 * HZ)
 
+/* BW rate limiting */
+#define I40E_BW_CREDIT_DIVISOR		50 /* 50Mbps per BW credit */
+#define I40E_MAX_BW_INACTIVE_ACCUM	4  /* accumulate 4 credits max */
+
 /* driver state flags */
 enum i40e_state_t {
 	__I40E_TESTING,
@@ -1039,4 +1043,5 @@ static inline bool i40e_enabled_xdp_vsi(struct i40e_vsi *vsi)
 }
 
 int i40e_create_queue_channel(struct i40e_vsi *vsi, struct i40e_channel *ch);
+int i40e_set_bw_limit(struct i40e_vsi *vsi, u16 seid, u64 max_tx_rate);
 #endif /* _I40E_H_ */

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -5399,6 +5399,70 @@ out:
 	return ret;
 }
 
+/**
+ * i40e_get_link_speed - Returns link speed for the interface
+ * @vsi: VSI to be configured
+ *
+ **/
+int i40e_get_link_speed(struct i40e_vsi *vsi)
+{
+	struct i40e_pf *pf = vsi->back;
+
+	switch (pf->hw.phy.link_info.link_speed) {
+	case I40E_LINK_SPEED_40GB:
+		return 40000;
+	case I40E_LINK_SPEED_25GB:
+		return 25000;
+	case I40E_LINK_SPEED_20GB:
+		return 20000;
+	case I40E_LINK_SPEED_10GB:
+		return 10000;
+	case I40E_LINK_SPEED_1GB:
+		return 1000;
+	default:
+		return -EINVAL;
+	}
+}
+
+/**
+ * i40e_set_bw_limit - setup BW limit for Tx traffic based on max_tx_rate
+ * @vsi: VSI to be configured
+ * @seid: seid of the channel/VSI
+ * @max_tx_rate: max TX rate to be configured as BW limit
+ *
+ * Helper function to set BW limit for a given VSI
+ **/
+int i40e_set_bw_limit(struct i40e_vsi *vsi, u16 seid, u64 max_tx_rate)
+{
+	struct i40e_pf *pf = vsi->back;
+	int speed = 0;
+	int ret = 0;
+
+	speed = i40e_get_link_speed(vsi);
+	if (max_tx_rate > speed) {
+		dev_err(&pf->pdev->dev,
+			"Invalid max tx rate %llu specified for VSI seid %d.",
+			max_tx_rate, seid);
+		return -EINVAL;
+	}
+	if (max_tx_rate && max_tx_rate < 50) {
+		dev_warn(&pf->pdev->dev,
+			 "Setting max tx rate to minimum usable value of 50Mbps.\n");
+		max_tx_rate = 50;
+	}
+
+	/* Tx rate credits are in values of 50Mbps, 0 is disabled */
+	ret = i40e_aq_config_vsi_bw_limit(&pf->hw, seid,
+					  max_tx_rate / I40E_BW_CREDIT_DIVISOR,
+					  I40E_MAX_BW_INACTIVE_ACCUM, NULL);
+	if (ret)
+		dev_err(&pf->pdev->dev,
+			"Failed set tx rate (%llu Mbps) for vsi->seid %u, err %s aq_err %s\n",
+			max_tx_rate, seid, i40e_stat_str(&pf->hw, ret),
+			i40e_aq_str(&pf->hw, pf->hw.aq.asq_last_status));
+	return ret;
+}
+
 /**
  * i40e_remove_queue_channels - Remove queue channels for the TCs
  * @vsi: VSI to be configured

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -3117,8 +3117,6 @@ error_pvid:
 	return ret;
 }
 
-#define I40E_BW_CREDIT_DIVISOR 50     /* 50Mbps per BW credit */
-#define I40E_MAX_BW_INACTIVE_ACCUM 4  /* device can accumulate 4 credits max */
 /**
  * i40e_ndo_set_vf_bw
  * @netdev: network interface device structure
@@ -3134,7 +3132,6 @@ int i40e_ndo_set_vf_bw(struct net_device *netdev, int vf_id, int min_tx_rate,
 	struct i40e_pf *pf = np->vsi->back;
 	struct i40e_vsi *vsi;
 	struct i40e_vf *vf;
-	int speed = 0;
 	int ret = 0;
 
 	/* validate the request */
@@ -3159,48 +3156,10 @@ int i40e_ndo_set_vf_bw(struct net_device *netdev, int vf_id, int min_tx_rate,
 		goto error;
 	}
 
-	switch (pf->hw.phy.link_info.link_speed) {
-	case I40E_LINK_SPEED_40GB:
-		speed = 40000;
-		break;
-	case I40E_LINK_SPEED_25GB:
-		speed = 25000;
-		break;
-	case I40E_LINK_SPEED_20GB:
-		speed = 20000;
-		break;
-	case I40E_LINK_SPEED_10GB:
-		speed = 10000;
-		break;
-	case I40E_LINK_SPEED_1GB:
-		speed = 1000;
-		break;
-	default:
-		break;
-	}
-
-	if (max_tx_rate > speed) {
-		dev_err(&pf->pdev->dev, "Invalid max tx rate %d specified for VF %d.\n",
-			max_tx_rate, vf->vf_id);
-		ret = -EINVAL;
+	ret = i40e_set_bw_limit(vsi, vsi->seid, max_tx_rate);
+	if (ret)
 		goto error;
-	}
 
-	if ((max_tx_rate < 50) && (max_tx_rate > 0)) {
-		dev_warn(&pf->pdev->dev, "Setting max Tx rate to minimum usable value of 50Mbps.\n");
-		max_tx_rate = 50;
-	}
-
-	/* Tx rate credits are in values of 50Mbps, 0 is disabled*/
-	ret = i40e_aq_config_vsi_bw_limit(&pf->hw, vsi->seid,
-					  max_tx_rate / I40E_BW_CREDIT_DIVISOR,
-					  I40E_MAX_BW_INACTIVE_ACCUM, NULL);
-	if (ret) {
-		dev_err(&pf->pdev->dev, "Unable to set max tx rate, error code %d.\n",
-			ret);
-		ret = -EIO;
-		goto error;
-	}
 	vf->tx_rate = max_tx_rate;
 error:
 	return ret;