2 files changed, 42 insertions, 13 deletions

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index f3a312c9413b..1322a2db6dba 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6724,6 +6724,20 @@ static void igc_save_mqprio_params(struct igc_adapter *adapter, u8 num_tc,
 		adapter->queue_per_tc[i] = offset[i];
 }
 
+static bool
+igc_tsn_is_tc_to_queue_priority_ordered(struct tc_mqprio_qopt_offload *mqprio)
+{
+	int num_tc = mqprio->qopt.num_tc;
+	int i;
+
+	for (i = 1; i < num_tc; i++) {
+		if (mqprio->qopt.offset[i - 1] > mqprio->qopt.offset[i])
+			return false;
+	}
+
+	return true;
+}
+
 static int igc_tsn_enable_mqprio(struct igc_adapter *adapter,
 				 struct tc_mqprio_qopt_offload *mqprio)
 {
@@ -6756,6 +6770,12 @@ static int igc_tsn_enable_mqprio(struct igc_adapter *adapter,
 		}
 	}
 
+	if (!igc_tsn_is_tc_to_queue_priority_ordered(mqprio)) {
+		NL_SET_ERR_MSG_MOD(mqprio->extack,
+				   "tc to queue mapping must preserve increasing priority (higher tc -> higher queue)");
+		return -EOPNOTSUPP;
+	}
+
 	/* Preemption is not supported yet. */
 	if (mqprio->preemptible_tcs) {
 		NL_SET_ERR_MSG_MOD(mqprio->extack,
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index f22cc4d4f459..78a4a9cf5f96 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -13,6 +13,13 @@
 #define TX_MAX_FRAG_SIZE	(TX_MIN_FRAG_SIZE * \
 				 (MAX_MULTPLIER_TX_MIN_FRAG + 1))
 
+enum tx_queue {
+	TX_QUEUE_0 = 0,
+	TX_QUEUE_1,
+	TX_QUEUE_2,
+	TX_QUEUE_3,
+};
+
 DEFINE_STATIC_KEY_FALSE(igc_fpe_enabled);
 
 static int igc_fpe_init_smd_frame(struct igc_ring *ring,
@@ -238,7 +245,7 @@ bool igc_tsn_is_taprio_activated_by_user(struct igc_adapter *adapter)
 		adapter->taprio_offload_enable;
 }
 
-static void igc_tsn_tx_arb(struct igc_adapter *adapter, u16 *queue_per_tc)
+static void igc_tsn_tx_arb(struct igc_adapter *adapter, bool reverse_prio)
 {
 	struct igc_hw *hw = &adapter->hw;
 	u32 txarb;
@@ -250,10 +257,17 @@ static void igc_tsn_tx_arb(struct igc_adapter *adapter, u16 *queue_per_tc)
 		   IGC_TXARB_TXQ_PRIO_2_MASK |
 		   IGC_TXARB_TXQ_PRIO_3_MASK);
 
-	txarb |= IGC_TXARB_TXQ_PRIO_0(queue_per_tc[3]);
-	txarb |= IGC_TXARB_TXQ_PRIO_1(queue_per_tc[2]);
-	txarb |= IGC_TXARB_TXQ_PRIO_2(queue_per_tc[1]);
-	txarb |= IGC_TXARB_TXQ_PRIO_3(queue_per_tc[0]);
+	if (reverse_prio) {
+		txarb |= IGC_TXARB_TXQ_PRIO_0(TX_QUEUE_3);
+		txarb |= IGC_TXARB_TXQ_PRIO_1(TX_QUEUE_2);
+		txarb |= IGC_TXARB_TXQ_PRIO_2(TX_QUEUE_1);
+		txarb |= IGC_TXARB_TXQ_PRIO_3(TX_QUEUE_0);
+	} else {
+		txarb |= IGC_TXARB_TXQ_PRIO_0(TX_QUEUE_0);
+		txarb |= IGC_TXARB_TXQ_PRIO_1(TX_QUEUE_1);
+		txarb |= IGC_TXARB_TXQ_PRIO_2(TX_QUEUE_2);
+		txarb |= IGC_TXARB_TXQ_PRIO_3(TX_QUEUE_3);
+	}
 
 	wr32(IGC_TXARB, txarb);
 }
@@ -286,7 +300,6 @@ static void igc_tsn_set_rxpbsize(struct igc_adapter *adapter,
  */
 static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 {
-	u16 queue_per_tc[4] = { 3, 2, 1, 0 };
 	struct igc_hw *hw = &adapter->hw;
 	u32 tqavctrl;
 	int i;
@@ -319,7 +332,7 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 	/* Restore the default Tx arbitration: Priority 0 has the highest
 	 * priority and is assigned to queue 0 and so on and so forth.
 	 */
-	igc_tsn_tx_arb(adapter, queue_per_tc);
+	igc_tsn_tx_arb(adapter, false);
 
 	adapter->flags &= ~IGC_FLAG_TSN_QBV_ENABLED;
 
@@ -385,12 +398,8 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	if (igc_is_device_id_i226(hw))
 		igc_tsn_set_retx_qbvfullthreshold(adapter);
 
-	if (adapter->strict_priority_enable) {
-		/* Configure queue priorities according to the user provided
-		 * mapping.
-		 */
-		igc_tsn_tx_arb(adapter, adapter->queue_per_tc);
-	}
+	if (adapter->strict_priority_enable)
+		igc_tsn_tx_arb(adapter, true);
 
 	for (i = 0; i < adapter->num_tx_queues; i++) {
 		struct igc_ring *ring = adapter->tx_ring[i];