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path: root/drivers/pci/msi/api.c
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Diffstat (limited to 'drivers/pci/msi/api.c')
-rw-r--r--drivers/pci/msi/api.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c
index 1714905943fb..8546749afa6e 100644
--- a/drivers/pci/msi/api.c
+++ b/drivers/pci/msi/api.c
@@ -123,3 +123,62 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
flags, NULL);
}
EXPORT_SYMBOL(pci_alloc_irq_vectors);
+
+/**
+ * pci_alloc_irq_vectors_affinity() - Allocate multiple device interrupt
+ * vectors with affinity requirements
+ * @dev: the PCI device to operate on
+ * @min_vecs: minimum required number of vectors (must be >= 1)
+ * @max_vecs: maximum desired number of vectors
+ * @flags: allocation flags, as in pci_alloc_irq_vectors()
+ * @affd: affinity requirements (can be %NULL).
+ *
+ * Same as pci_alloc_irq_vectors(), but with the extra @affd parameter.
+ * Check that function docs, and &struct irq_affinity, for more details.
+ */
+int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
+ unsigned int max_vecs, unsigned int flags,
+ struct irq_affinity *affd)
+{
+ struct irq_affinity msi_default_affd = {0};
+ int nvecs = -ENOSPC;
+
+ if (flags & PCI_IRQ_AFFINITY) {
+ if (!affd)
+ affd = &msi_default_affd;
+ } else {
+ if (WARN_ON(affd))
+ affd = NULL;
+ }
+
+ if (flags & PCI_IRQ_MSIX) {
+ nvecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs,
+ affd, flags);
+ if (nvecs > 0)
+ return nvecs;
+ }
+
+ if (flags & PCI_IRQ_MSI) {
+ nvecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd);
+ if (nvecs > 0)
+ return nvecs;
+ }
+
+ /* use legacy IRQ if allowed */
+ if (flags & PCI_IRQ_LEGACY) {
+ if (min_vecs == 1 && dev->irq) {
+ /*
+ * Invoke the affinity spreading logic to ensure that
+ * the device driver can adjust queue configuration
+ * for the single interrupt case.
+ */
+ if (affd)
+ irq_create_affinity_masks(1, affd);
+ pci_intx(dev, 1);
+ return 1;
+ }
+ }
+
+ return nvecs;
+}
+EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);