Merge branch 'remotes/lorenzo/pci/vmd'

bjorn-helgaas · bjorn-helgaas · commit fa687fb9ced4 · 2018-08-15T14:59:16.000-05:00
- Whitelist VMD devices with fast interrupt handlers to avoid sharing
    vectors with slow handlers (Keith Busch)

* remotes/lorenzo/pci/vmd:
  PCI: vmd: White list for fast interrupt handlers
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
@@ -197,9 +197,20 @@ static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *d
 	int i, best = 1;
 	unsigned long flags;
 
-	if (pci_is_bridge(msi_desc_to_pci_dev(desc)) || vmd->msix_count == 1)
+	if (vmd->msix_count == 1)
 		return &vmd->irqs[0];
 
+	/*
+	 * White list for fast-interrupt handlers. All others will share the
+	 * "slow" interrupt vector.
+	 */
+	switch (msi_desc_to_pci_dev(desc)->class) {
+	case PCI_CLASS_STORAGE_EXPRESS:
+		break;
+	default:
+		return &vmd->irqs[0];
+	}
+
 	raw_spin_lock_irqsave(&list_lock, flags);
 	for (i = 1; i < vmd->msix_count; i++)
 		if (vmd->irqs[i].count < vmd->irqs[best].count)
