Commit 06b41258 authored by Muhammad Husaini Zulkifli's avatar Muhammad Husaini Zulkifli Committed by Jakub Kicinski
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igc: Add lock to safeguard global Qbv variables 



Access to shared variables through hrtimer requires locking in order
to protect the variables because actions to write into these variables
(oper_gate_closed, admin_gate_closed, and qbv_transition) might potentially
occur simultaneously. This patch provides a locking mechanisms to avoid
such scenarios.

Fixes: 175c2412 ("igc: Fix TX Hang issue when QBV Gate is closed")
Suggested-by: default avatarLeon Romanovsky <leon@kernel.org>
Signed-off-by: default avatarMuhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: default avatarNaama Meir <naamax.meir@linux.intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20230807205129.3129346-1-anthony.l.nguyen@intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b9077ef4

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

+4 −0
Original line number Diff line number Diff line
@@ -195,6 +195,10 @@ struct igc_adapter { 
	u32 qbv_config_change_errors;

	bool qbv_transition;

	unsigned int qbv_count;

	/* Access to oper_gate_closed, admin_gate_closed and qbv_transition

	 * are protected by the qbv_tx_lock.

	 */

	spinlock_t qbv_tx_lock;



	/* OS defined structs */

	struct pci_dev *pdev;

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

+32 −2
Original line number Diff line number Diff line
@@ -4801,6 +4801,7 @@ static int igc_sw_init(struct igc_adapter *adapter) 
	adapter->nfc_rule_count = 0;



	spin_lock_init(&adapter->stats64_lock);

	spin_lock_init(&adapter->qbv_tx_lock);

	/* Assume MSI-X interrupts, will be checked during IRQ allocation */

	adapter->flags |= IGC_FLAG_HAS_MSIX;
@@ -6119,15 +6120,15 @@ static int igc_tsn_enable_launchtime(struct igc_adapter *adapter, 
	return igc_tsn_offload_apply(adapter);

}



static int igc_tsn_clear_schedule(struct igc_adapter *adapter)

static int igc_qbv_clear_schedule(struct igc_adapter *adapter)

{

	unsigned long flags;

	int i;



	adapter->base_time = 0;

	adapter->cycle_time = NSEC_PER_SEC;

	adapter->taprio_offload_enable = false;

	adapter->qbv_config_change_errors = 0;

	adapter->qbv_transition = false;

	adapter->qbv_count = 0;



	for (i = 0; i < adapter->num_tx_queues; i++) {
@@ -6136,10 +6137,28 @@ static int igc_tsn_clear_schedule(struct igc_adapter *adapter) 
		ring->start_time = 0;

		ring->end_time = NSEC_PER_SEC;

		ring->max_sdu = 0;

	}



	spin_lock_irqsave(&adapter->qbv_tx_lock, flags);



	adapter->qbv_transition = false;



	for (i = 0; i < adapter->num_tx_queues; i++) {

		struct igc_ring *ring = adapter->tx_ring[i];



		ring->oper_gate_closed = false;

		ring->admin_gate_closed = false;

	}



	spin_unlock_irqrestore(&adapter->qbv_tx_lock, flags);



	return 0;

}



static int igc_tsn_clear_schedule(struct igc_adapter *adapter)

{

	igc_qbv_clear_schedule(adapter);



	return 0;

}
@@ -6150,6 +6169,7 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter, 
	struct igc_hw *hw = &adapter->hw;

	u32 start_time = 0, end_time = 0;

	struct timespec64 now;

	unsigned long flags;

	size_t n;

	int i;
@@ -6217,6 +6237,8 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter, 
		start_time += e->interval;

	}



	spin_lock_irqsave(&adapter->qbv_tx_lock, flags);



	/* Check whether a queue gets configured.

	 * If not, set the start and end time to be end time.

	 */
@@ -6241,6 +6263,8 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter, 
		}

	}



	spin_unlock_irqrestore(&adapter->qbv_tx_lock, flags);



	for (i = 0; i < adapter->num_tx_queues; i++) {

		struct igc_ring *ring = adapter->tx_ring[i];

		struct net_device *dev = adapter->netdev;
@@ -6619,8 +6643,11 @@ static enum hrtimer_restart igc_qbv_scheduling_timer(struct hrtimer *timer) 
{

	struct igc_adapter *adapter = container_of(timer, struct igc_adapter,

						   hrtimer);

	unsigned long flags;

	unsigned int i;



	spin_lock_irqsave(&adapter->qbv_tx_lock, flags);



	adapter->qbv_transition = true;

	for (i = 0; i < adapter->num_tx_queues; i++) {

		struct igc_ring *tx_ring = adapter->tx_ring[i];
@@ -6633,6 +6660,9 @@ static enum hrtimer_restart igc_qbv_scheduling_timer(struct hrtimer *timer) 
		}

	}

	adapter->qbv_transition = false;



	spin_unlock_irqrestore(&adapter->qbv_tx_lock, flags);



	return HRTIMER_NORESTART;

}