qed: Add DCBX API - qed_dcbx_get_priority_tc()

The API receives a priority and looks for the TC it is mapped to in the
operational DCBX configuration. The API returns QED_DCBX_DEFAULT_TC (0)
when DCBX is disabled.
Signed-off-by: Michal Kalderon <michal.kalderon@cavium.com>
Signed-off-by: Ariel Elior <ariel.elior@cavium.com>
Signed-off-by: Denis Bolotin <denis.bolotin@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qed/qed_dcbx.c

@@ -989,6 +989,24 @@ void qed_dcbx_set_pf_update_params(struct qed_dcbx_results *p_src,
 	qed_dcbx_update_protocol_data(p_dcb_data, p_src, DCBX_PROTOCOL_ETH);
 }
 
+u8 qed_dcbx_get_priority_tc(struct qed_hwfn *p_hwfn, u8 pri)
+{
+	struct qed_dcbx_get *dcbx_info = &p_hwfn->p_dcbx_info->get;
+
+	if (pri >= QED_MAX_PFC_PRIORITIES) {
+		DP_ERR(p_hwfn, "Invalid priority %d\n", pri);
+		return QED_DCBX_DEFAULT_TC;
+	}
+
+	if (!dcbx_info->operational.valid) {
+		DP_VERBOSE(p_hwfn, QED_MSG_DCB,
+			   "Dcbx parameters not available\n");
+		return QED_DCBX_DEFAULT_TC;
+	}
+
+	return dcbx_info->operational.params.ets_pri_tc_tbl[pri];
+}
+
 #ifdef CONFIG_DCB
 static int qed_dcbx_query_params(struct qed_hwfn *p_hwfn,
 				 struct qed_dcbx_get *p_get,

drivers/net/ethernet/qlogic/qed/qed_dcbx.h

@@ -123,4 +123,7 @@ void qed_dcbx_info_free(struct qed_hwfn *p_hwfn);
 void qed_dcbx_set_pf_update_params(struct qed_dcbx_results *p_src,
 				   struct pf_update_ramrod_data *p_dest);
 
+#define QED_DCBX_DEFAULT_TC	0
+
+u8 qed_dcbx_get_priority_tc(struct qed_hwfn *p_hwfn, u8 pri);
 #endif