[PATCH net-next v3 8/8] igc: Separate TSN configurations that can be updated

[Vinicius Costa Gomes <vinicius.gomes@intel.com>]

Some TSN features can be enabled during runtime, but most of the
features need an adapter reset to be disabled.

To better keep track of this, separate the process into an "_apply"
and a "reset" functions, "_apply" will run with the adapter in
potencially "dirty" state, and if necessary will request an adapter
reset, so "_reset" always run with a "clean" adapter.

The idea is to make the process easier to follow.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c |  21 ++--
 drivers/net/ethernet/intel/igc/igc_tsn.c  | 139 +++++++++++++++-------
 drivers/net/ethernet/intel/igc/igc_tsn.h  |   1 +
 3 files changed, 102 insertions(+), 59 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index b05fdf739e7f..f45944968980 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -108,7 +108,7 @@ 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);
 }
@@ -4812,6 +4812,11 @@ static int igc_save_frame_preemption(struct igc_adapter *adapter,
 	u32 preempt;
 	int i;
 
+	/* What we want here is just to save the configuration, so
+	 * when frame preemption is enabled via ethtool, which queues
+	 * are marked as preemptible is saved.
+	 */
+
 	preempt = qopt->preemptible_queues;
 
 	for (i = 0; i < adapter->num_tx_queues; i++) {
@@ -4839,18 +4844,6 @@ static int igc_tsn_enable_qbv_scheduling(struct igc_adapter *adapter,
 	return igc_tsn_offload_apply(adapter);
 }
 
-static int igc_tsn_enable_frame_preemption(struct igc_adapter *adapter,
-					   struct tc_preempt_qopt_offload *qopt)
-{
-	int err;
-
-	err = igc_save_frame_preemption(adapter, qopt);
-	if (err)
-		return err;
-
-	return igc_tsn_offload_apply(adapter);
-}
-
 static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
 			void *type_data)
 {
@@ -4864,7 +4857,7 @@ static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
 		return igc_tsn_enable_launchtime(adapter, type_data);
 
 	case TC_SETUP_PREEMPT:
-		return igc_tsn_enable_frame_preemption(adapter, type_data);
+		return igc_save_frame_preemption(adapter, type_data);
 
 	default:
 		return -EOPNOTSUPP;
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 31aa9eed3ae3..fdb472a80967 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -18,8 +18,24 @@ 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;
+
+	if (adapter->frame_preemption_active)
+		new_flags |= IGC_FLAG_TSN_PREEMPT_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)
 {
@@ -27,9 +43,6 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 	u32 tqavctrl, rxpbs;
 	int i;
 
-	if (!(adapter->flags & IGC_FLAG_TSN_QBV_ENABLED))
-		return 0;
-
 	adapter->base_time = 0;
 	adapter->cycle_time = 0;
 	adapter->frame_preemption_active = false;
@@ -65,38 +78,25 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 	wr32(IGC_QBVCYCLET_S, NSEC_PER_MSEC);
 	wr32(IGC_QBVCYCLET, NSEC_PER_MSEC);
 
-	adapter->flags &= ~IGC_FLAG_TSN_QBV_ENABLED;
+	adapter->flags &= ~IGC_FLAG_TSN_ANY_ENABLED;
 
 	return 0;
 }
 
-static int igc_tsn_enable_offload(struct igc_adapter *adapter)
+static int igc_tsn_update_params(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
-	u32 tqavctrl, baset_l, baset_h;
-	u32 sec, nsec, cycle, rxpbs;
-	ktime_t base_time, systim;
+	unsigned int flags;
 	u8 frag_size_mult;
+	u32 tqavctrl;
 	int i;
 
-	if (adapter->flags & IGC_FLAG_TSN_QBV_ENABLED)
+	flags = igc_tsn_new_flags(adapter) & IGC_FLAG_TSN_ANY_ENABLED;
+	if (!flags)
 		return 0;
 
-	cycle = adapter->cycle_time;
-	base_time = adapter->base_time;
-
-	wr32(IGC_TSAUXC, 0);
-	wr32(IGC_DTXMXPKTSZ, IGC_DTXMXPKTSZ_TSN);
-	wr32(IGC_TXPBS, IGC_TXPBSIZE_TSN);
-
-	rxpbs = rd32(IGC_RXPBS) & ~IGC_RXPBSIZE_SIZE_MASK;
-	rxpbs |= IGC_RXPBSIZE_TSN;
-
-	wr32(IGC_RXPBS, rxpbs);
-
 	tqavctrl = rd32(IGC_TQAVCTRL) &
 		~(IGC_TQAVCTRL_MIN_FRAG_MASK | IGC_TQAVCTRL_PREEMPT_ENA);
-	tqavctrl |= IGC_TQAVCTRL_TRANSMIT_MODE_TSN | IGC_TQAVCTRL_ENHANCED_QAV;
 
 	if (adapter->frame_preemption_active)
 		tqavctrl |= IGC_TQAVCTRL_PREEMPT_ENA;
@@ -107,9 +107,6 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 
 	wr32(IGC_TQAVCTRL, tqavctrl);
 
-	wr32(IGC_QBVCYCLET_S, cycle);
-	wr32(IGC_QBVCYCLET, cycle);
-
 	for (i = 0; i < adapter->num_tx_queues; i++) {
 		struct igc_ring *ring = adapter->tx_ring[i];
 		u32 txqctl = 0;
@@ -130,12 +127,47 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 		if (ring->launchtime_enable)
 			txqctl |= IGC_TXQCTL_QUEUE_MODE_LAUNCHT;
 
-		if (ring->preemptible)
+		if (adapter->frame_preemption_active && ring->preemptible)
 			txqctl |= IGC_TXQCTL_PREEMPTABLE;
 
 		wr32(IGC_TXQCTL(i), txqctl);
 	}
 
+	adapter->flags = igc_tsn_new_flags(adapter);
+
+	return 0;
+}
+
+static int igc_tsn_enable_offload(struct igc_adapter *adapter)
+{
+	struct igc_hw *hw = &adapter->hw;
+	u32 baset_l, baset_h, tqavctrl;
+	u32 sec, nsec, cycle, rxpbs;
+	ktime_t base_time, systim;
+
+	tqavctrl = rd32(IGC_TQAVCTRL);
+	tqavctrl |= IGC_TQAVCTRL_TRANSMIT_MODE_TSN | IGC_TQAVCTRL_ENHANCED_QAV;
+
+	wr32(IGC_TQAVCTRL, tqavctrl);
+
+	wr32(IGC_TSAUXC, 0);
+	wr32(IGC_DTXMXPKTSZ, IGC_DTXMXPKTSZ_TSN);
+	wr32(IGC_TXPBS, IGC_TXPBSIZE_TSN);
+
+	rxpbs = rd32(IGC_RXPBS) & ~IGC_RXPBSIZE_SIZE_MASK;
+	rxpbs |= IGC_RXPBSIZE_TSN;
+
+	wr32(IGC_RXPBS, rxpbs);
+
+	if (!adapter->base_time)
+		goto done;
+
+	cycle = adapter->cycle_time;
+	base_time = adapter->base_time;
+
+	wr32(IGC_QBVCYCLET_S, cycle);
+	wr32(IGC_QBVCYCLET, cycle);
+
 	nsec = rd32(IGC_SYSTIML);
 	sec = rd32(IGC_SYSTIMH);
 
@@ -153,34 +185,51 @@ 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;
+done:
+	igc_tsn_update_params(adapter);
 
 	return 0;
 }
 
+int igc_tsn_reset(struct igc_adapter *adapter)
+{
+	unsigned int new_flags;
+	int err = 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;
+
+	adapter->flags = new_flags;
+
+	return err;
+}
+
 int igc_tsn_offload_apply(struct igc_adapter *adapter)
 {
-	bool is_any_enabled = adapter->base_time ||
-		is_any_launchtime(adapter) || adapter->frame_preemption_active;
+	unsigned int new_flags, old_flags;
 
-	if (!(adapter->flags & IGC_FLAG_TSN_QBV_ENABLED) && !is_any_enabled)
-		return 0;
+	old_flags = adapter->flags;
+	new_flags = igc_tsn_new_flags(adapter);
 
-	if (!is_any_enabled) {
-		int err = igc_tsn_disable_offload(adapter);
+	if (old_flags == new_flags)
+		return igc_tsn_update_params(adapter);
 
-		if (err < 0)
-			return err;
+	/* Enabling features work without resetting the adapter */
+	if (new_flags > old_flags)
+		return igc_tsn_enable_offload(adapter);
 
-		/* 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);
+	adapter->flags = new_flags;
 
-		return 0;
-	}
+	if (!netif_running(adapter->netdev))
+		return igc_tsn_enable_offload(adapter);
 
-	return igc_tsn_enable_offload(adapter);
+	schedule_work(&adapter->reset_task);
+
+	return 0;
 }
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.h b/drivers/net/ethernet/intel/igc/igc_tsn.h
index f76bc86ddccd..1512307f5a52 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.h
+++ b/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 */
-- 
2.30.0