igc: Simplify TSN flags handling

Separates the procedure done during reset from applying a
configuration, knowing when the code is executing allow us to
separate the better what changes the hardware state from what
changes only the driver state.

Introduces a flag for bookkeeping the driver state of TSN
features. When Qav and frame-preemption is also implemented
this flag makes it easier to keep track on whether a TSN feature
driver state is enabled or not though controller state changes,
say, during a reset.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Aravindhan Gunasekaran <aravindhan.gunasekaran@intel.com>
Signed-off-by: Mallikarjuna Chilakala <mallikarjuna.chilakala@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/igc/igc.h

@@ -291,6 +291,8 @@ extern char igc_driver_name[];
 #define IGC_FLAG_RX_LEGACY		BIT(16)
 #define IGC_FLAG_TSN_QBV_ENABLED	BIT(17)
 
+#define IGC_FLAG_TSN_ANY_ENABLED	IGC_FLAG_TSN_QBV_ENABLED
+
 #define IGC_FLAG_RSS_FIELD_IPV4_UDP	BIT(6)
 #define IGC_FLAG_RSS_FIELD_IPV6_UDP	BIT(7)
 

drivers/net/ethernet/intel/igc/igc_main.c

@@ -120,7 +120,7 @@ void igc_reset(struct igc_adapter *adapter)
 	igc_ptp_reset(adapter);
 
 	/* Re-enable TSN offloading, where applicable. */
-	igc_tsn_offload_apply(adapter);
+	igc_tsn_reset(adapter);
 
 	igc_get_phy_info(hw);
 }

drivers/net/ethernet/intel/igc/igc_tsn.c

@@ -18,20 +18,28 @@ static bool is_any_launchtime(struct igc_adapter *adapter)
 	return false;
 }
 
+static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter)
+{
+	unsigned int new_flags = adapter->flags & ~IGC_FLAG_TSN_ANY_ENABLED;
+
+	if (adapter->base_time)
+		new_flags |= IGC_FLAG_TSN_QBV_ENABLED;
+
+	if (is_any_launchtime(adapter))
+		new_flags |= IGC_FLAG_TSN_QBV_ENABLED;
+
+	return new_flags;
+}
+
 /* Returns the TSN specific registers to their default values after
- * TSN offloading is disabled.
+ * the adapter is reset.
  */
 static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
 	u32 tqavctrl;
 	int i;
 
-	if (!(adapter->flags & IGC_FLAG_TSN_QBV_ENABLED))
-		return 0;
-
-	adapter->cycle_time = 0;
-
 	wr32(IGC_TXPBS, I225_TXPBSIZE_DEFAULT);
 	wr32(IGC_DTXMXPKTSZ, IGC_DTXMXPKTSZ_DEFAULT);
 
@@ -62,9 +70,6 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	ktime_t base_time, systim;
 	int i;
 
-	if (adapter->flags & IGC_FLAG_TSN_QBV_ENABLED)
-		return 0;
-
 	cycle = adapter->cycle_time;
 	base_time = adapter->base_time;
 
@@ -119,33 +124,41 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	wr32(IGC_BASET_H, baset_h);
 	wr32(IGC_BASET_L, baset_l);
 
-	adapter->flags |= IGC_FLAG_TSN_QBV_ENABLED;
-
 	return 0;
 }
 
-int igc_tsn_offload_apply(struct igc_adapter *adapter)
+int igc_tsn_reset(struct igc_adapter *adapter)
 {
-	bool is_any_enabled = adapter->base_time || is_any_launchtime(adapter);
+	unsigned int new_flags;
+	int err = 0;
 
-	if (!(adapter->flags & IGC_FLAG_TSN_QBV_ENABLED) && !is_any_enabled)
-		return 0;
+	new_flags = igc_tsn_new_flags(adapter);
+
+	if (!(new_flags & IGC_FLAG_TSN_ANY_ENABLED))
+		return igc_tsn_disable_offload(adapter);
+
+	err = igc_tsn_enable_offload(adapter);
+	if (err < 0)
+		return err;
 
-	if (!is_any_enabled) {
-		int err = igc_tsn_disable_offload(adapter);
+	adapter->flags = new_flags;
 
-		if (err < 0)
-			return err;
+	return err;
+}
 
-		/* The BASET registers aren't cleared when writing
-		 * into them, force a reset if the interface is
-		 * running.
-		 */
-		if (netif_running(adapter->netdev))
-			schedule_work(&adapter->reset_task);
+int igc_tsn_offload_apply(struct igc_adapter *adapter)
+{
+	int err;
 
+	if (netif_running(adapter->netdev)) {
+		schedule_work(&adapter->reset_task);
 		return 0;
 	}
 
-	return igc_tsn_enable_offload(adapter);
+	err = igc_tsn_enable_offload(adapter);
+	if (err < 0)
+		return err;
+
+	adapter->flags = igc_tsn_new_flags(adapter);
+	return 0;
 }

drivers/net/ethernet/intel/igc/igc_tsn.h

@@ -5,5 +5,6 @@
 #define _IGC_TSN_H_
 
 int igc_tsn_offload_apply(struct igc_adapter *adapter);
+int igc_tsn_reset(struct igc_adapter *adapter);
 
 #endif /* _IGC_BASE_H */