From 4ef33685aa0957d771e068b60a5f3ca6b47ade1c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 12 Jul 2016 18:20:18 +0900 Subject: PCI: Spread interrupt vectors in pci_alloc_irq_vectors() Set the affinity_mask in the PCI device before allocating vectors so that the affinity can be propagated through the MSI descriptor structures to the core IRQ code. To facilitate this, new __pci_enable_msi_range() and __pci_enable_msix_range() helpers are factored out of their not prefixed variants which assigning the new IRQ affinity mask in the PCI device so that the low-level interrupt code can perform the interrupt affinity assignment and do node-local allocations. A new PCI_IRQ_NOAFFINITY flag is added to pci_alloc_irq_vectors() so that this function can also be used by drivers that don't wish to use the automatic affinity assignment. [bhelgaas: omit "else" after "return" consistently] Signed-off-by: Christoph Hellwig Signed-off-by: Bjorn Helgaas Reviewed-by: Alexander Gordeev --- Documentation/PCI/MSI-HOWTO.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation/PCI') diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt index 0ac612b8c3fb..c55df2911136 100644 --- a/Documentation/PCI/MSI-HOWTO.txt +++ b/Documentation/PCI/MSI-HOWTO.txt @@ -99,6 +99,10 @@ PCI_IRQ_NOMSI and PCI_IRQ_NOMSIX flag in case a device claims to support MSI or MSI-X, but the support is broken, or to pass PCI_IRQ_NOLEGACY in case the device does not support legacy interrupt lines. +By default this function will spread the interrupts around the available +CPUs, but this feature can be disabled by passing the PCI_IRQ_NOAFFINITY +flag. + To get the Linux IRQ numbers passed to request_irq() and free_irq() and the vectors, use the following function: -- cgit v1.2.3