diff options
| author | Christoph Hellwig <hch@lst.de> | 2016-07-12 18:20:18 +0900 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2016-07-21 15:57:03 -0500 |
| commit | 4ef33685aa0957d771e068b60a5f3ca6b47ade1c (patch) | |
| tree | 34e9fee3bd177657e18f56a4d5d0701f6f3c20f5 /Documentation/PCI/MSI-HOWTO.txt | |
| parent | aff171641d181ea573380efc3f559c9de4741fc5 (diff) | |
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 <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alexander Gordeev <agordeev@redhat.com>
Diffstat (limited to 'Documentation/PCI/MSI-HOWTO.txt')
| -rw-r--r-- | Documentation/PCI/MSI-HOWTO.txt | 4 |
1 files changed, 4 insertions, 0 deletions
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: |