Add a reverse-mapping function to return the interrupt vector for
any CPU if interrupt affinity is enabled.
Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
---
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))
+ return entry->irq;
+ }
+ return -EINVAL;
+ } else if (dev->msi_enabled) {
+ struct msi_desc *entry = first_pci_msi_entry(dev);
+ int nr;
+
+ if (!entry)
+ return -ENOENT;
+
+ for (nr = 0; nr < entry->nvec_used; nr++) {
+ if (cpumask_test_cpu(cpu, &entry->affinity[nr]))
+ return dev->irq + nr;
+ }
+ return -EINVAL;
+ } else {
+ return dev->irq;
+ }
+}
+EXPORT_SYMBOL(pci_irq_get_affinity_vector);
+
struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
{
return to_pci_dev(desc->dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0e49f70..2dd0817 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1315,6 +1315,7 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
void pci_free_irq_vectors(struct pci_dev *dev);
int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev, int vec);
+int pci_irq_get_affinity_vector(struct pci_dev *pdev, int cpu);
#else
static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; }
--
1.8.5.6
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