+/**
+ * msix_capability_init - configure device's MSI-X capability
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ * @entries: pointer to an array of struct msix_entry entries
+ * @nvec: number of @entries
+ *
+ * Setup the MSI-X capability structure of device function with a
+ * single MSI-X irq. A return of zero indicates the successful setup of
+ * requested MSI-X entries with allocated irqs or non-zero for otherwise.
+ **/
+static int msix_capability_init(struct pci_dev *dev,
+ struct msix_entry *entries, int nvec)
+{
+ int pos, ret;
+ u16 control;
+ void __iomem *base;
+
+ pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
+ pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
+
+ /* Ensure MSI-X is disabled while it is set up */
+ control &= ~PCI_MSIX_FLAGS_ENABLE;
+ pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
+
+ /* Request & Map MSI-X table region */
+ base = msix_map_region(dev, pos, multi_msix_capable(control));
+ if (!base)
+ return -ENOMEM;
+
+ ret = msix_setup_entries(dev, pos, base, entries, nvec);
+ if (ret)