2 files changed, 51 insertions, 20 deletions

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index fcbcd188a132..04aade842097 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1269,9 +1269,20 @@ static irqreturn_t ena_intr_msix_io(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+/* Reserve a single MSI-X vector for management (admin + aenq).
+ * plus reserve one vector for each potential io queue.
+ * the number of potential io queues is the minimum of what the device
+ * supports and the number of vCPUs.
+ */
 static int ena_enable_msix(struct ena_adapter *adapter, int num_queues)
 {
-	int msix_vecs, rc;
+	int msix_vecs, irq_cnt;
+
+	if (test_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags)) {
+		netif_err(adapter, probe, adapter->netdev,
+			  "Error, MSI-X is already enabled\n");
+		return -EPERM;
+	}
 
 	/* Reserved the max msix vectors we might need */
 	msix_vecs = ENA_MAX_MSIX_VEC(num_queues);
@@ -1279,25 +1290,28 @@ static int ena_enable_msix(struct ena_adapter *adapter, int num_queues)
 	netif_dbg(adapter, probe, adapter->netdev,
 		  "trying to enable MSI-X, vectors %d\n", msix_vecs);
 
-	rc = pci_alloc_irq_vectors(adapter->pdev, msix_vecs, msix_vecs,
-			PCI_IRQ_MSIX);
-	if (rc < 0) {
+	irq_cnt = pci_alloc_irq_vectors(adapter->pdev, ENA_MIN_MSIX_VEC,
+					msix_vecs, PCI_IRQ_MSIX);
+
+	if (irq_cnt < 0) {
 		netif_err(adapter, probe, adapter->netdev,
-			  "Failed to enable MSI-X, vectors %d rc %d\n",
-			  msix_vecs, rc);
+			  "Failed to enable MSI-X. irq_cnt %d\n", irq_cnt);
 		return -ENOSPC;
 	}
 
-	netif_dbg(adapter, probe, adapter->netdev, "enable MSI-X, vectors %d\n",
-		  msix_vecs);
-
-	if (msix_vecs >= 1) {
-		if (ena_init_rx_cpu_rmap(adapter))
-			netif_warn(adapter, probe, adapter->netdev,
-				   "Failed to map IRQs to CPUs\n");
+	if (irq_cnt != msix_vecs) {
+		netif_notice(adapter, probe, adapter->netdev,
+			     "enable only %d MSI-X (out of %d), reduce the number of queues\n",
+			     irq_cnt, msix_vecs);
+		adapter->num_queues = irq_cnt - ENA_ADMIN_MSIX_VEC;
 	}
 
-	adapter->msix_vecs = msix_vecs;
+	if (ena_init_rx_cpu_rmap(adapter))
+		netif_warn(adapter, probe, adapter->netdev,
+			   "Failed to map IRQs to CPUs\n");
+
+	adapter->msix_vecs = irq_cnt;
+	set_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags);
 
 	return 0;
 }
@@ -1374,6 +1388,12 @@ static int ena_request_io_irq(struct ena_adapter *adapter)
 	struct ena_irq *irq;
 	int rc = 0, i, k;
 
+	if (!test_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags)) {
+		netif_err(adapter, ifup, adapter->netdev,
+			  "Failed to request I/O IRQ: MSI-X is not enabled\n");
+		return -EINVAL;
+	}
+
 	for (i = ENA_IO_IRQ_FIRST_IDX; i < adapter->msix_vecs; i++) {
 		irq = &adapter->irq_tbl[i];
 		rc = request_irq(irq->vector, irq->handler, flags, irq->name,
@@ -1432,6 +1452,12 @@ static void ena_free_io_irq(struct ena_adapter *adapter)
 	}
 }
 
+static void ena_disable_msix(struct ena_adapter *adapter)
+{
+	if (test_and_clear_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags))
+		pci_free_irq_vectors(adapter->pdev);
+}
+
 static void ena_disable_io_intr_sync(struct ena_adapter *adapter)
 {
 	int i;
@@ -2520,7 +2546,8 @@ static int ena_enable_msix_and_set_admin_interrupts(struct ena_adapter *adapter,
 	return 0;
 
 err_disable_msix:
-	pci_free_irq_vectors(adapter->pdev);
+	ena_disable_msix(adapter);
+
 	return rc;
 }
 
@@ -2558,7 +2585,7 @@ static void ena_fw_reset_device(struct work_struct *work)
 
 	ena_free_mgmnt_irq(adapter);
 
-	pci_free_irq_vectors(adapter->pdev);
+	ena_disable_msix(adapter);
 
 	ena_com_abort_admin_commands(ena_dev);
 
@@ -2610,7 +2637,7 @@ static void ena_fw_reset_device(struct work_struct *work)
 	return;
 err_disable_msix:
 	ena_free_mgmnt_irq(adapter);
-	pci_free_irq_vectors(adapter->pdev);
+	ena_disable_msix(adapter);
 err_device_destroy:
 	ena_com_admin_destroy(ena_dev);
 err:
@@ -3269,7 +3296,7 @@ err_rss:
 err_free_msix:
 	ena_com_dev_reset(ena_dev, ENA_REGS_RESET_INIT_ERR);
 	ena_free_mgmnt_irq(adapter);
-	pci_free_irq_vectors(adapter->pdev);
+	ena_disable_msix(adapter);
 err_worker_destroy:
 	ena_com_destroy_interrupt_moderation(ena_dev);
 	del_timer(&adapter->timer_service);
@@ -3354,7 +3381,7 @@ static void ena_remove(struct pci_dev *pdev)
 
 	ena_free_mgmnt_irq(adapter);
 
-	pci_free_irq_vectors(adapter->pdev);
+	ena_disable_msix(adapter);
 
 	free_netdev(netdev);
 
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index 5edc3da96ce5..86b0f0dbae65 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -58,7 +58,10 @@
 #define DEVICE_NAME	"Elastic Network Adapter (ENA)"
 
 /* 1 for AENQ + ADMIN */
-#define ENA_MAX_MSIX_VEC(io_queues)	(1 + (io_queues))
+#define ENA_ADMIN_MSIX_VEC		1
+#define ENA_MAX_MSIX_VEC(io_queues)	(ENA_ADMIN_MSIX_VEC + (io_queues))
+
+#define ENA_MIN_MSIX_VEC		2
 
 #define ENA_REG_BAR			0
 #define ENA_MEM_BAR			2
@@ -267,6 +270,7 @@ enum ena_flags_t {
 	ENA_FLAG_DEVICE_RUNNING,
 	ENA_FLAG_DEV_UP,
 	ENA_FLAG_LINK_UP,
+	ENA_FLAG_MSIX_ENABLED,
 	ENA_FLAG_TRIGGER_RESET
 };