From b60b869d5f9f0987cf4e3fee22fb88786a281de7 Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Tue, 18 Feb 2014 11:12:02 +0100 Subject: [PATCH] vmxnet3: Fix MSI-X/MSI enablement code This update cleans up the MSI-X/MSI enablement code, fixes vmxnet3_acquire_msix_vectors() invalid return values and enables a dead code in case VMXNET3_LINUX_MIN_MSIX_VECT MSI-X vectors were allocated. Signed-off-by: Alexander Gordeev Cc: Shreyas Bhatewara Cc: pv-drivers@vmware.com Cc: netdev@vger.kernel.org Cc: linux-pci@vger.kernel.org Signed-off-by: David S. Miller --- drivers/net/vmxnet3/vmxnet3_drv.c | 101 ++++++++++++++---------------- 1 file changed, 46 insertions(+), 55 deletions(-) diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index 3be786faaaec..3a17797e0817 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -2729,47 +2729,44 @@ vmxnet3_read_mac_addr(struct vmxnet3_adapter *adapter, u8 *mac) /* * Enable MSIx vectors. * Returns : - * 0 on successful enabling of required vectors, * VMXNET3_LINUX_MIN_MSIX_VECT when only minimum number of vectors required - * could be enabled. - * number of vectors which can be enabled otherwise (this number is smaller + * were enabled. + * number of vectors which were enabled otherwise (this number is greater * than VMXNET3_LINUX_MIN_MSIX_VECT) */ static int -vmxnet3_acquire_msix_vectors(struct vmxnet3_adapter *adapter, - int vectors) +vmxnet3_acquire_msix_vectors(struct vmxnet3_adapter *adapter, int nvec) { - int err = 0, vector_threshold; - vector_threshold = VMXNET3_LINUX_MIN_MSIX_VECT; - - while (vectors >= vector_threshold) { - err = pci_enable_msix(adapter->pdev, adapter->intr.msix_entries, - vectors); + do { + int err = pci_enable_msix(adapter->pdev, + adapter->intr.msix_entries, nvec); if (!err) { - adapter->intr.num_intrs = vectors; - return 0; + return nvec; } else if (err < 0) { dev_err(&adapter->netdev->dev, - "Failed to enable MSI-X, error: %d\n", err); - vectors = 0; - } else if (err < vector_threshold) { - break; + "Failed to enable MSI-X, error: %d\n", err); + return err; + } else if (err < VMXNET3_LINUX_MIN_MSIX_VECT) { + dev_info(&adapter->pdev->dev, + "Number of MSI-X which can be allocated " + "is lower than min threshold required.\n"); + return -ENOSPC; } else { /* If fails to enable required number of MSI-x vectors * try enabling minimum number of vectors required. */ dev_err(&adapter->netdev->dev, - "Failed to enable %d MSI-X, trying %d instead\n", - vectors, vector_threshold); - vectors = vector_threshold; + "Failed to enable %d MSI-X, trying %d\n", + nvec, VMXNET3_LINUX_MIN_MSIX_VECT); + nvec = VMXNET3_LINUX_MIN_MSIX_VECT; } - } + } while (nvec >= VMXNET3_LINUX_MIN_MSIX_VECT); - dev_info(&adapter->pdev->dev, - "Number of MSI-X interrupts which can be allocated " - "is lower than min threshold required.\n"); - return err; + /* + * Should never get here + */ + return -ENOSPC; } @@ -2796,56 +2793,50 @@ vmxnet3_alloc_intr_resources(struct vmxnet3_adapter *adapter) #ifdef CONFIG_PCI_MSI if (adapter->intr.type == VMXNET3_IT_MSIX) { - int vector, err = 0; - - adapter->intr.num_intrs = (adapter->share_intr == - VMXNET3_INTR_TXSHARE) ? 1 : - adapter->num_tx_queues; - adapter->intr.num_intrs += (adapter->share_intr == - VMXNET3_INTR_BUDDYSHARE) ? 0 : - adapter->num_rx_queues; - adapter->intr.num_intrs += 1; /* for link event */ - - adapter->intr.num_intrs = (adapter->intr.num_intrs > - VMXNET3_LINUX_MIN_MSIX_VECT - ? adapter->intr.num_intrs : - VMXNET3_LINUX_MIN_MSIX_VECT); - - for (vector = 0; vector < adapter->intr.num_intrs; vector++) - adapter->intr.msix_entries[vector].entry = vector; - - err = vmxnet3_acquire_msix_vectors(adapter, - adapter->intr.num_intrs); + int i, nvec; + + nvec = adapter->share_intr == VMXNET3_INTR_TXSHARE ? + 1 : adapter->num_tx_queues; + nvec += adapter->share_intr == VMXNET3_INTR_BUDDYSHARE ? + 0 : adapter->num_rx_queues; + nvec += 1; /* for link event */ + nvec = nvec > VMXNET3_LINUX_MIN_MSIX_VECT ? + nvec : VMXNET3_LINUX_MIN_MSIX_VECT; + + for (i = 0; i < nvec; i++) + adapter->intr.msix_entries[i].entry = i; + + nvec = vmxnet3_acquire_msix_vectors(adapter, nvec); + if (nvec < 0) + goto msix_err; + /* If we cannot allocate one MSIx vector per queue * then limit the number of rx queues to 1 */ - if (err == VMXNET3_LINUX_MIN_MSIX_VECT) { + if (nvec == VMXNET3_LINUX_MIN_MSIX_VECT) { if (adapter->share_intr != VMXNET3_INTR_BUDDYSHARE || adapter->num_rx_queues != 1) { adapter->share_intr = VMXNET3_INTR_TXSHARE; netdev_err(adapter->netdev, "Number of rx queues : 1\n"); adapter->num_rx_queues = 1; - adapter->intr.num_intrs = - VMXNET3_LINUX_MIN_MSIX_VECT; } - return; } - if (!err) - return; + adapter->intr.num_intrs = nvec; + return; + +msix_err: /* If we cannot allocate MSIx vectors use only one rx queue */ dev_info(&adapter->pdev->dev, "Failed to enable MSI-X, error %d. " - "Limiting #rx queues to 1, try MSI.\n", err); + "Limiting #rx queues to 1, try MSI.\n", nvec); adapter->intr.type = VMXNET3_IT_MSI; } if (adapter->intr.type == VMXNET3_IT_MSI) { - int err; - err = pci_enable_msi(adapter->pdev); - if (!err) { + if (!pci_enable_msi(adapter->pdev)) { adapter->num_rx_queues = 1; adapter->intr.num_intrs = 1; return; -- 2.20.1