On Tue, 8 Nov 2016, Hannes Reinecke wrote:
> Add a reverse-mapping function to return the interrupt vector for
> any CPU if interrupt affinity is enabled.
>
> Signed-off-by: Hannes Reinecke <h...@suse.com>
> ---
> drivers/pci/msi.c | 36 ++++++++++++++++++++++++++++++++++++
> include/linux/pci.h | 1 +
> 2 files changed, 37 insertions(+)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index bfdd074..de5ed32 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -1302,6 +1302,42 @@ const struct cpumask *pci_irq_get_affinity(struct
> pci_dev *dev, int nr)
> }
> EXPORT_SYMBOL(pci_irq_get_affinity);
>
> +/**
> + * pci_irq_get_affinity_vector - return the vector number for a given CPU
> + * @dev: PCI device to operate on
> + * @cpu: cpu number
> + *
> + * Returns the vector number for CPU @cpu or a negative error number
> + * if interrupt affinity is not set.
> + */
> +int pci_irq_get_affinity_vector(struct pci_dev *dev, int cpu)
> +{
> + if (dev->msix_enabled) {
> + struct msi_desc *entry;
> +
> + for_each_pci_msi_entry(entry, dev) {
> + if (cpumask_test_cpu(cpu, entry->affinity))
entry->affinity can be NULL
