diff options
Diffstat (limited to 'drivers/pci/msi/api.c')
| -rw-r--r-- | drivers/pci/msi/api.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c index 20a580bea48f..93ddc5570693 100644 --- a/drivers/pci/msi/api.c +++ b/drivers/pci/msi/api.c @@ -9,6 +9,7 @@ */ #include <linux/export.h> +#include <linux/irq.h> #include "msi.h" @@ -251,6 +252,48 @@ int pci_irq_vector(struct pci_dev *dev, unsigned int nr) EXPORT_SYMBOL(pci_irq_vector); /** + * pci_irq_get_affinity() - Get a device interrupt vector affinity + * @dev: the PCI device to operate on + * @nr: device-relative interrupt vector index (0-based); has different + * meanings, depending on interrupt mode + * MSI-X the index in the MSI-X vector table + * MSI the index of the enabled MSI vectors + * INTx must be 0 + * + * Return: MSI/MSI-X vector affinity, NULL if @nr is out of range or if + * the MSI(-X) vector was allocated without explicit affinity + * requirements (e.g., by pci_enable_msi(), pci_enable_msix_range(), or + * pci_alloc_irq_vectors() without the %PCI_IRQ_AFFINITY flag). Return a + * generic set of CPU IDs representing all possible CPUs available + * during system boot if the device is in legacy INTx mode. + */ +const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr) +{ + int idx, irq = pci_irq_vector(dev, nr); + struct msi_desc *desc; + + if (WARN_ON_ONCE(irq <= 0)) + return NULL; + + desc = irq_get_msi_desc(irq); + /* Non-MSI does not have the information handy */ + if (!desc) + return cpu_possible_mask; + + /* MSI[X] interrupts can be allocated without affinity descriptor */ + if (!desc->affinity) + return NULL; + + /* + * MSI has a mask array in the descriptor. + * MSI-X has a single mask. + */ + idx = dev->msi_enabled ? nr : 0; + return &desc->affinity[idx].mask; +} +EXPORT_SYMBOL(pci_irq_get_affinity); + +/** * pci_free_irq_vectors() - Free previously allocated IRQs for a device * @dev: the PCI device to operate on * |