From 1e4822d1394ab7e192eff168a0c1b3c7c4ca24ff Mon Sep 17 00:00:00 2001 From: Hauke Mehrtens Date: Sat, 1 Dec 2018 22:38:24 +0100 Subject: backports: Fix pci_alloc_irq_vectors() backport This copies the pci_alloc_irq_vectors() function from kernel 4.9 and replaces the __pci_enable_msi{x}_range() calls with calls to pci_enable_msi{x}_range(), these were backported to kernel versions < 3.14, so no need to handle the older kernels specially here. This also adds support for MSIx IRQs and adds the PCI_IRQ_* defines. Fixes: 162a6b312f1b ("add support for pci_alloc_irq_vectors") Signed-off-by: Hauke Mehrtens Cc: Omer Dagan --- backport/backport-include/linux/pci.h | 8 ++++++ backport/compat/backport-4.8.c | 49 +++++++++++++++++++++++++---------- 2 files changed, 44 insertions(+), 13 deletions(-) diff --git a/backport/backport-include/linux/pci.h b/backport/backport-include/linux/pci.h index 531f5a47..3a141bf3 100644 --- a/backport/backport-include/linux/pci.h +++ b/backport/backport-include/linux/pci.h @@ -224,4 +224,12 @@ static inline struct pci_dev *pcie_find_root_port(struct pci_dev *dev) #endif/* <4.9.0 but not >= 3.12.69, 4.4.37, 4.8.13 */ +#ifndef PCI_IRQ_LEGACY +#define PCI_IRQ_LEGACY (1 << 0) /* Allow legacy interrupts */ +#define PCI_IRQ_MSI (1 << 1) /* Allow MSI interrupts */ +#define PCI_IRQ_MSIX (1 << 2) /* Allow MSI-X interrupts */ +#define PCI_IRQ_ALL_TYPES \ + (PCI_IRQ_LEGACY | PCI_IRQ_MSI | PCI_IRQ_MSIX) +#endif + #endif /* _BACKPORT_LINUX_PCI_H */ 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 */ -- cgit v1.2.3