pci/msi: Retrieve affinity for a vector
Add a helper to get the affinity mask for a given PCI irq vector. For MSI or
MSI-X vectors these are stored by the IRQ core, while for legacy interrupts
we will always return cpu_possible_map.
[hch: updated to follow the style of pci_irq_vector()]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Link: http://lkml.kernel.org/r/1473862739-15032-6-git-send-email-hch@lst.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 06100dd..9da5ecb 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1270,6 +1270,37 @@
}
EXPORT_SYMBOL(pci_irq_vector);
+/**
+ * pci_irq_get_affinity - return the affinity of a particular msi vector
+ * @dev: PCI device to operate on
+ * @nr: device-relative interrupt vector index (0-based).
+ */
+const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
+{
+ if (dev->msix_enabled) {
+ struct msi_desc *entry;
+ int i = 0;
+
+ for_each_pci_msi_entry(entry, dev) {
+ if (i == nr)
+ return entry->affinity;
+ i++;
+ }
+ WARN_ON_ONCE(1);
+ return NULL;
+ } else if (dev->msi_enabled) {
+ struct msi_desc *entry = first_pci_msi_entry(dev);
+
+ if (WARN_ON_ONCE(!entry || nr >= entry->nvec_used))
+ return NULL;
+
+ return &entry->affinity[nr];
+ } else {
+ return cpu_possible_mask;
+ }
+}
+EXPORT_SYMBOL(pci_irq_get_affinity);
+
struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
{
return to_pci_dev(desc->dev);