amd-xgbe: Enable/disable PFC per traffic class

Currently the PFC flow control is enabled on all traffic classes if
one or more traffic classes request it. The PFC enable setting of the
traffic class should be used to determine whether to enable or disable
flow control for the traffic class.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-dev.c

@@ -518,13 +518,45 @@ static int xgbe_disable_tx_flow_control(struct xgbe_prv_data *pdata)
 
 static int xgbe_enable_tx_flow_control(struct xgbe_prv_data *pdata)
 {
+	struct ieee_pfc *pfc = pdata->pfc;
+	struct ieee_ets *ets = pdata->ets;
 	unsigned int max_q_count, q_count;
 	unsigned int reg, reg_val;
 	unsigned int i;
 
 	/* Set MTL flow control */
-	for (i = 0; i < pdata->rx_q_count; i++)
-		XGMAC_MTL_IOWRITE_BITS(pdata, i, MTL_Q_RQOMR, EHFC, 1);
+	for (i = 0; i < pdata->rx_q_count; i++) {
+		unsigned int ehfc = 0;
+
+		if (pfc && ets) {
+			unsigned int prio;
+
+			for (prio = 0; prio < IEEE_8021QAZ_MAX_TCS; prio++) {
+				unsigned int tc;
+
+				/* Does this queue handle the priority? */
+				if (pdata->prio2q_map[prio] != i)
+					continue;
+
+				/* Get the Traffic Class for this priority */
+				tc = ets->prio_tc[prio];
+
+				/* Check if flow control should be enabled */
+				if (pfc->pfc_en & (1 << tc)) {
+					ehfc = 1;
+					break;
+				}
+			}
+		} else {
+			ehfc = 1;
+		}
+
+		XGMAC_MTL_IOWRITE_BITS(pdata, i, MTL_Q_RQOMR, EHFC, ehfc);
+
+		netif_dbg(pdata, drv, pdata->netdev,
+			  "flow control %s for RXq%u\n",
+			  ehfc ? "enabled" : "disabled", i);
+	}
 
 	/* Set MAC flow control */
 	max_q_count = XGMAC_MAX_FLOW_CONTROL_QUEUES;