1 files changed, 189 insertions, 133 deletions

diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
index e05aca9bef0e..b8245c734c96 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
@@ -123,11 +123,24 @@ static void fm10k_service_timer(unsigned long data)
 static void fm10k_detach_subtask(struct fm10k_intfc *interface)
 {
 	struct net_device *netdev = interface->netdev;
+	u32 __iomem *hw_addr;
+	u32 value;
 
 	/* do nothing if device is still present or hw_addr is set */
 	if (netif_device_present(netdev) || interface->hw.hw_addr)
 		return;
 
+	/* check the real address space to see if we've recovered */
+	hw_addr = READ_ONCE(interface->uc_addr);
+	value = readl(hw_addr);
+	if ((~value)) {
+		interface->hw.hw_addr = interface->uc_addr;
+		netif_device_attach(netdev);
+		interface->flags |= FM10K_FLAG_RESET_REQUESTED;
+		netdev_warn(netdev, "PCIe link restored, device now attached\n");
+		return;
+	}
+
 	rtnl_lock();
 
 	if (netif_running(netdev))
@@ -136,11 +149,9 @@ static void fm10k_detach_subtask(struct fm10k_intfc *interface)
 	rtnl_unlock();
 }
 
-static void fm10k_reinit(struct fm10k_intfc *interface)
+static void fm10k_prepare_for_reset(struct fm10k_intfc *interface)
 {
 	struct net_device *netdev = interface->netdev;
-	struct fm10k_hw *hw = &interface->hw;
-	int err;
 
 	WARN_ON(in_interrupt());
 
@@ -165,6 +176,19 @@ static void fm10k_reinit(struct fm10k_intfc *interface)
 	/* delay any future reset requests */
 	interface->last_reset = jiffies + (10 * HZ);
 
+	rtnl_unlock();
+}
+
+static int fm10k_handle_reset(struct fm10k_intfc *interface)
+{
+	struct net_device *netdev = interface->netdev;
+	struct fm10k_hw *hw = &interface->hw;
+	int err;
+
+	rtnl_lock();
+
+	pci_set_master(interface->pdev);
+
 	/* reset and initialize the hardware so it is in a known state */
 	err = hw->mac.ops.reset_hw(hw);
 	if (err) {
@@ -185,7 +209,7 @@ static void fm10k_reinit(struct fm10k_intfc *interface)
 		goto reinit_err;
 	}
 
-	/* reassociate interrupts */
+	/* re-associate interrupts */
 	err = fm10k_mbx_request_irq(interface);
 	if (err)
 		goto err_mbx_irq;
@@ -219,7 +243,7 @@ static void fm10k_reinit(struct fm10k_intfc *interface)
 
 	clear_bit(__FM10K_RESETTING, &interface->state);
 
-	return;
+	return err;
 err_open:
 	fm10k_mbx_free_irq(interface);
 err_mbx_irq:
@@ -230,6 +254,20 @@ reinit_err:
 	rtnl_unlock();
 
 	clear_bit(__FM10K_RESETTING, &interface->state);
+
+	return err;
+}
+
+static void fm10k_reinit(struct fm10k_intfc *interface)
+{
+	int err;
+
+	fm10k_prepare_for_reset(interface);
+
+	err = fm10k_handle_reset(interface);
+	if (err)
+		dev_err(&interface->pdev->dev,
+			"fm10k_handle_reset failed: %d\n", err);
 }
 
 static void fm10k_reset_subtask(struct fm10k_intfc *interface)
@@ -372,12 +410,19 @@ void fm10k_update_stats(struct fm10k_intfc *interface)
 	u64 bytes, pkts;
 	int i;
 
+	/* ensure only one thread updates stats at a time */
+	if (test_and_set_bit(__FM10K_UPDATING_STATS, &interface->state))
+		return;
+
 	/* do not allow stats update via service task for next second */
 	interface->next_stats_update = jiffies + HZ;
 
 	/* gather some stats to the interface struct that are per queue */
 	for (bytes = 0, pkts = 0, i = 0; i < interface->num_tx_queues; i++) {
-		struct fm10k_ring *tx_ring = interface->tx_ring[i];
+		struct fm10k_ring *tx_ring = READ_ONCE(interface->tx_ring[i]);
+
+		if (!tx_ring)
+			continue;
 
 		restart_queue += tx_ring->tx_stats.restart_queue;
 		tx_busy += tx_ring->tx_stats.tx_busy;
@@ -396,7 +441,10 @@ void fm10k_update_stats(struct fm10k_intfc *interface)
 
 	/* gather some stats to the interface struct that are per queue */
 	for (bytes = 0, pkts = 0, i = 0; i < interface->num_rx_queues; i++) {
-		struct fm10k_ring *rx_ring = interface->rx_ring[i];
+		struct fm10k_ring *rx_ring = READ_ONCE(interface->rx_ring[i]);
+
+		if (!rx_ring)
+			continue;
 
 		bytes += rx_ring->stats.bytes;
 		pkts += rx_ring->stats.packets;
@@ -443,6 +491,8 @@ void fm10k_update_stats(struct fm10k_intfc *interface)
 	/* Fill out the OS statistics structure */
 	net_stats->rx_errors = rx_errors;
 	net_stats->rx_dropped = interface->stats.nodesc_drop.count;
+
+	clear_bit(__FM10K_UPDATING_STATS, &interface->state);
 }
 
 /**
@@ -1566,6 +1616,9 @@ void fm10k_up(struct fm10k_intfc *interface)
 	/* configure interrupts */
 	hw->mac.ops.update_int_moderator(hw);
 
+	/* enable statistics capture again */
+	clear_bit(__FM10K_UPDATING_STATS, &interface->state);
+
 	/* clear down bit to indicate we are ready to go */
 	clear_bit(__FM10K_DOWN, &interface->state);
 
@@ -1598,10 +1651,11 @@ void fm10k_down(struct fm10k_intfc *interface)
 {
 	struct net_device *netdev = interface->netdev;
 	struct fm10k_hw *hw = &interface->hw;
-	int err;
+	int err, i = 0, count = 0;
 
 	/* signal that we are down to the interrupt handler and service task */
-	set_bit(__FM10K_DOWN, &interface->state);
+	if (test_and_set_bit(__FM10K_DOWN, &interface->state))
+		return;
 
 	/* call carrier off first to avoid false dev_watchdog timeouts */
 	netif_carrier_off(netdev);
@@ -1613,18 +1667,57 @@ void fm10k_down(struct fm10k_intfc *interface)
 	/* reset Rx filters */
 	fm10k_reset_rx_state(interface);
 
-	/* allow 10ms for device to quiesce */
-	usleep_range(10000, 20000);
-
 	/* disable polling routines */
 	fm10k_napi_disable_all(interface);
 
 	/* capture stats one last time before stopping interface */
 	fm10k_update_stats(interface);
 
+	/* prevent updating statistics while we're down */
+	while (test_and_set_bit(__FM10K_UPDATING_STATS, &interface->state))
+		usleep_range(1000, 2000);
+
+	/* skip waiting for TX DMA if we lost PCIe link */
+	if (FM10K_REMOVED(hw->hw_addr))
+		goto skip_tx_dma_drain;
+
+	/* In some rare circumstances it can take a while for Tx queues to
+	 * quiesce and be fully disabled. Attempt to .stop_hw() first, and
+	 * then if we get ERR_REQUESTS_PENDING, go ahead and wait in a loop
+	 * until the Tx queues have emptied, or until a number of retries. If
+	 * we fail to clear within the retry loop, we will issue a warning
+	 * indicating that Tx DMA is probably hung. Note this means we call
+	 * .stop_hw() twice but this shouldn't cause any problems.
+	 */
+	err = hw->mac.ops.stop_hw(hw);
+	if (err != FM10K_ERR_REQUESTS_PENDING)
+		goto skip_tx_dma_drain;
+
+#define TX_DMA_DRAIN_RETRIES 25
+	for (count = 0; count < TX_DMA_DRAIN_RETRIES; count++) {
+		usleep_range(10000, 20000);
+
+		/* start checking at the last ring to have pending Tx */
+		for (; i < interface->num_tx_queues; i++)
+			if (fm10k_get_tx_pending(interface->tx_ring[i]))
+				break;
+
+		/* if all the queues are drained, we can break now */
+		if (i == interface->num_tx_queues)
+			break;
+	}
+
+	if (count >= TX_DMA_DRAIN_RETRIES)
+		dev_err(&interface->pdev->dev,
+			"Tx queues failed to drain after %d tries. Tx DMA is probably hung.\n",
+			count);
+skip_tx_dma_drain:
 	/* Disable DMA engine for Tx/Rx */
 	err = hw->mac.ops.stop_hw(hw);
-	if (err)
+	if (err == FM10K_ERR_REQUESTS_PENDING)
+		dev_err(&interface->pdev->dev,
+			"due to pending requests hw was not shut down gracefully\n");
+	else if (err)
 		dev_err(&interface->pdev->dev, "stop_hw failed: %d\n", err);
 
 	/* free any buffers still on the rings */
@@ -1750,6 +1843,7 @@ static int fm10k_sw_init(struct fm10k_intfc *interface,
 
 	/* Start off interface as being down */
 	set_bit(__FM10K_DOWN, &interface->state);
+	set_bit(__FM10K_UPDATING_STATS, &interface->state);
 
 	return 0;
 }
@@ -2033,6 +2127,48 @@ static void fm10k_remove(struct pci_dev *pdev)
 	pci_disable_device(pdev);
 }
 
+static void fm10k_prepare_suspend(struct fm10k_intfc *interface)
+{
+	/* the watchdog task reads from registers, which might appear like
+	 * a surprise remove if the PCIe device is disabled while we're
+	 * stopped. We stop the watchdog task until after we resume software
+	 * activity.
+	 */
+	set_bit(__FM10K_SERVICE_DISABLE, &interface->state);
+	cancel_work_sync(&interface->service_task);
+
+	fm10k_prepare_for_reset(interface);
+}
+
+static int fm10k_handle_resume(struct fm10k_intfc *interface)
+{
+	struct fm10k_hw *hw = &interface->hw;
+	int err;
+
+	/* reset statistics starting values */
+	hw->mac.ops.rebind_hw_stats(hw, &interface->stats);
+
+	err = fm10k_handle_reset(interface);
+	if (err)
+		return err;
+
+	/* assume host is not ready, to prevent race with watchdog in case we
+	 * actually don't have connection to the switch
+	 */
+	interface->host_ready = false;
+	fm10k_watchdog_host_not_ready(interface);
+
+	/* force link to stay down for a second to prevent link flutter */
+	interface->link_down_event = jiffies + (HZ);
+	set_bit(__FM10K_LINK_DOWN, &interface->state);
+
+	/* clear the service task disable bit to allow service task to start */
+	clear_bit(__FM10K_SERVICE_DISABLE, &interface->state);
+	fm10k_service_event_schedule(interface);
+
+	return err;
+}
+
 #ifdef CONFIG_PM
 /**
  * fm10k_resume - Restore device to pre-sleep state
@@ -2069,60 +2205,13 @@ static int fm10k_resume(struct pci_dev *pdev)
 	/* refresh hw_addr in case it was dropped */
 	hw->hw_addr = interface->uc_addr;
 
-	/* reset hardware to known state */
-	err = hw->mac.ops.init_hw(&interface->hw);
-	if (err) {
-		dev_err(&pdev->dev, "init_hw failed: %d\n", err);
-		return err;
-	}
-
-	/* reset statistics starting values */
-	hw->mac.ops.rebind_hw_stats(hw, &interface->stats);
-
-	rtnl_lock();
-
-	err = fm10k_init_queueing_scheme(interface);
-	if (err)
-		goto err_queueing_scheme;
-
-	err = fm10k_mbx_request_irq(interface);
-	if (err)
-		goto err_mbx_irq;
-
-	err = fm10k_hw_ready(interface);
+	err = fm10k_handle_resume(interface);
 	if (err)
-		goto err_open;
-
-	err = netif_running(netdev) ? fm10k_open(netdev) : 0;
-	if (err)
-		goto err_open;
-
-	rtnl_unlock();
-
-	/* assume host is not ready, to prevent race with watchdog in case we
-	 * actually don't have connection to the switch
-	 */
-	interface->host_ready = false;
-	fm10k_watchdog_host_not_ready(interface);
-
-	/* clear the service task disable bit to allow service task to start */
-	clear_bit(__FM10K_SERVICE_DISABLE, &interface->state);
-	fm10k_service_event_schedule(interface);
-
-	/* restore SR-IOV interface */
-	fm10k_iov_resume(pdev);
+		return err;
 
 	netif_device_attach(netdev);
 
 	return 0;
-err_open:
-	fm10k_mbx_free_irq(interface);
-err_mbx_irq:
-	fm10k_clear_queueing_scheme(interface);
-err_queueing_scheme:
-	rtnl_unlock();
-
-	return err;
 }
 
 /**
@@ -2142,27 +2231,7 @@ static int fm10k_suspend(struct pci_dev *pdev,
 
 	netif_device_detach(netdev);
 
-	fm10k_iov_suspend(pdev);
-
-	/* the watchdog tasks may read registers, which will appear like a
-	 * surprise-remove event once the PCI device is disabled. This will
-	 * cause us to close the netdevice, so we don't retain the open/closed
-	 * state post-resume. Prevent this by disabling the service task while
-	 * suspended, until we actually resume.
-	 */
-	set_bit(__FM10K_SERVICE_DISABLE, &interface->state);
-	cancel_work_sync(&interface->service_task);
-
-	rtnl_lock();
-
-	if (netif_running(netdev))
-		fm10k_close(netdev);
-
-	fm10k_mbx_free_irq(interface);
-
-	fm10k_clear_queueing_scheme(interface);
-
-	rtnl_unlock();
+	fm10k_prepare_suspend(interface);
 
 	err = pci_save_state(pdev);
 	if (err)
@@ -2195,17 +2264,7 @@ static pci_ers_result_t fm10k_io_error_detected(struct pci_dev *pdev,
 	if (state == pci_channel_io_perm_failure)
 		return PCI_ERS_RESULT_DISCONNECT;
 
-	rtnl_lock();
-
-	if (netif_running(netdev))
-		fm10k_close(netdev);
-
-	fm10k_mbx_free_irq(interface);
-
-	/* free interrupts */
-	fm10k_clear_queueing_scheme(interface);
-
-	rtnl_unlock();
+	fm10k_prepare_suspend(interface);
 
 	/* Request a slot reset. */
 	return PCI_ERS_RESULT_NEED_RESET;
@@ -2219,7 +2278,6 @@ static pci_ers_result_t fm10k_io_error_detected(struct pci_dev *pdev,
  */
 static pci_ers_result_t fm10k_io_slot_reset(struct pci_dev *pdev)
 {
-	struct fm10k_intfc *interface = pci_get_drvdata(pdev);
 	pci_ers_result_t result;
 
 	if (pci_enable_device_mem(pdev)) {
@@ -2237,12 +2295,6 @@ static pci_ers_result_t fm10k_io_slot_reset(struct pci_dev *pdev)
 
 		pci_wake_from_d3(pdev, false);
 
-		/* refresh hw_addr in case it was dropped */
-		interface->hw.hw_addr = interface->uc_addr;
-
-		interface->flags |= FM10K_FLAG_RESET_REQUESTED;
-		fm10k_service_event_schedule(interface);
-
 		result = PCI_ERS_RESULT_RECOVERED;
 	}
 
@@ -2262,50 +2314,54 @@ static void fm10k_io_resume(struct pci_dev *pdev)
 {
 	struct fm10k_intfc *interface = pci_get_drvdata(pdev);
 	struct net_device *netdev = interface->netdev;
-	struct fm10k_hw *hw = &interface->hw;
-	int err = 0;
-
-	/* reset hardware to known state */
-	err = hw->mac.ops.init_hw(&interface->hw);
-	if (err) {
-		dev_err(&pdev->dev, "init_hw failed: %d\n", err);
-		return;
-	}
-
-	/* reset statistics starting values */
-	hw->mac.ops.rebind_hw_stats(hw, &interface->stats);
-
-	rtnl_lock();
+	int err;
 
-	err = fm10k_init_queueing_scheme(interface);
-	if (err) {
-		dev_err(&interface->pdev->dev,
-			"init_queueing_scheme failed: %d\n", err);
-		goto unlock;
-	}
+	err = fm10k_handle_resume(interface);
 
-	/* reassociate interrupts */
-	fm10k_mbx_request_irq(interface);
+	if (err)
+		dev_warn(&pdev->dev,
+			 "fm10k_io_resume failed: %d\n", err);
+	else
+		netif_device_attach(netdev);
+}
 
-	rtnl_lock();
-	if (netif_running(netdev))
-		err = fm10k_open(netdev);
-	rtnl_unlock();
+/**
+ * fm10k_io_reset_notify - called when PCI function is reset
+ * @pdev: Pointer to PCI device
+ *
+ * This callback is called when the PCI function is reset such as from
+ * /sys/class/net/<enpX>/device/reset or similar. When prepare is true, it
+ * means we should prepare for a function reset. If prepare is false, it means
+ * the function reset just occurred.
+ */
+static void fm10k_io_reset_notify(struct pci_dev *pdev, bool prepare)
+{
+	struct fm10k_intfc *interface = pci_get_drvdata(pdev);
+	int err = 0;
 
-	/* final check of hardware state before registering the interface */
-	err = err ? : fm10k_hw_ready(interface);
+	if (prepare) {
+		/* warn incase we have any active VF devices */
+		if (pci_num_vf(pdev))
+			dev_warn(&pdev->dev,
+				 "PCIe FLR may cause issues for any active VF devices\n");
 
-	if (!err)
-		netif_device_attach(netdev);
+		fm10k_prepare_suspend(interface);
+	} else {
+		err = fm10k_handle_resume(interface);
+	}
 
-unlock:
-	rtnl_unlock();
+	if (err) {
+		dev_warn(&pdev->dev,
+			 "fm10k_io_reset_notify failed: %d\n", err);
+		netif_device_detach(interface->netdev);
+	}
 }
 
 static const struct pci_error_handlers fm10k_err_handler = {
 	.error_detected = fm10k_io_error_detected,
 	.slot_reset = fm10k_io_slot_reset,
 	.resume = fm10k_io_resume,
+	.reset_notify = fm10k_io_reset_notify,
 };
 
 static struct pci_driver fm10k_driver = {