diff options
Diffstat (limited to 'backport/compat/backport-4.8.c')
| -rw-r--r-- | backport/compat/backport-4.8.c | 49 |
1 files changed, 36 insertions, 13 deletions
diff --git a/backport/compat/backport-4.8.c b/backport/compat/backport-4.8.c index a53e39c9..11b2e7d7 100644 --- a/backport/compat/backport-4.8.c +++ b/backport/compat/backport-4.8.c @@ -148,25 +148,48 @@ EXPORT_SYMBOL_GPL(cdc_parse_cdc_header); #ifdef CONFIG_PCI #ifdef CONFIG_PCI_MSI + +/** + * pci_alloc_irq_vectors - allocate multiple IRQs for a device + * @dev: PCI device to operate on + * @min_vecs: minimum number of vectors required (must be >= 1) + * @max_vecs: maximum (desired) number of vectors + * @flags: flags or quirks for the allocation + * + * Allocate up to @max_vecs interrupt vectors for @dev, using MSI-X or MSI + * vectors if available, and fall back to a single legacy vector + * if neither is available. Return the number of vectors allocated, + * (which might be smaller than @max_vecs) if successful, or a negative + * error code on error. If less than @min_vecs interrupt vectors are + * available for @dev the function will fail with -ENOSPC. + * + * To get the Linux IRQ number used for a vector that can be passed to + * request_irq() use the pci_irq_vector() helper. + */ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs, unsigned int max_vecs, unsigned int flags) { - int res; - int msi_nvect = max_vecs; + int vecs = -ENOSPC; - if (max_vecs < min_vecs) - return -ERANGE; + if (flags & PCI_IRQ_MSIX) { + vecs = pci_enable_msix_range(dev, NULL, min_vecs, max_vecs); + if (vecs > 0) + return vecs; + } + + if (flags & PCI_IRQ_MSI) { + vecs = pci_enable_msi_range(dev, min_vecs, max_vecs); + if (vecs > 0) + return vecs; + } -#if LINUX_VERSION_IS_LESS(3,15,0) - res = pci_enable_msi_block(dev, msi_nvect); - if (res == 0) { - return msi_nvect; + /* use legacy irq if allowed */ + if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1) { + pci_intx(dev, 1); + return 1; } -#else - res = pci_enable_msi_range(dev, msi_nvect, msi_nvect); - return msi_nvect; -#endif /*LINUX_VERSION_IS_LESS(3,15,0)*/ - return -ENOSPC; + + return vecs; } EXPORT_SYMBOL_GPL(pci_alloc_irq_vectors); #endif /* CONFIG_PCI_MSI */ |