Merge tag 'irq-urgent-2022-02-27' of git://git.kernel.org/pub/scm/lin…

…ux/kernel/git/tip/tip

Pull irq fix from Thomas Gleixner:
 "A single fix for a regression caused by the recent PCI/MSI rework
  which resulted in a recursive locking problem in the VMD driver.

  The cure is to cache the relevant information upfront instead of
  retrieving it at runtime"

* tag 'irq-urgent-2022-02-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  PCI: vmd: Prevent recursive locking on interrupt allocation

drivers/pci/controller/vmd.c

@@ -99,11 +99,13 @@ struct vmd_irq {
  * @srcu:	SRCU struct for local synchronization.
  * @count:	number of child IRQs assigned to this vector; used to track
  *		sharing.
+ * @virq:	The underlying VMD Linux interrupt number
  */
 struct vmd_irq_list {
 	struct list_head	irq_list;
 	struct srcu_struct	srcu;
 	unsigned int		count;
+	unsigned int		virq;
 };
 
 struct vmd_dev {
@@ -253,18 +255,15 @@ static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info,
 	struct msi_desc *desc = arg->desc;
 	struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus);
 	struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL);
-	unsigned int index, vector;
 
 	if (!vmdirq)
 		return -ENOMEM;
 
 	INIT_LIST_HEAD(&vmdirq->node);
 	vmdirq->irq = vmd_next_irq(vmd, desc);
 	vmdirq->virq = virq;
-	index = index_from_irqs(vmd, vmdirq->irq);
-	vector = pci_irq_vector(vmd->dev, index);
 
-	irq_domain_set_info(domain, virq, vector, info->chip, vmdirq,
+	irq_domain_set_info(domain, virq, vmdirq->irq->virq, info->chip, vmdirq,
 			    handle_untracked_irq, vmd, NULL);
 	return 0;
 }
@@ -685,7 +684,8 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd)
 			return err;
 
 		INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
-		err = devm_request_irq(&dev->dev, pci_irq_vector(dev, i),
+		vmd->irqs[i].virq = pci_irq_vector(dev, i);
+		err = devm_request_irq(&dev->dev, vmd->irqs[i].virq,
 				       vmd_irq, IRQF_NO_THREAD,
 				       vmd->name, &vmd->irqs[i]);
 		if (err)
@@ -969,7 +969,7 @@ static int vmd_suspend(struct device *dev)
 	int i;
 
 	for (i = 0; i < vmd->msix_count; i++)
-		devm_free_irq(dev, pci_irq_vector(pdev, i), &vmd->irqs[i]);
+		devm_free_irq(dev, vmd->irqs[i].virq, &vmd->irqs[i]);
 
 	return 0;
 }
@@ -981,7 +981,7 @@ static int vmd_resume(struct device *dev)
 	int err, i;
 
 	for (i = 0; i < vmd->msix_count; i++) {
-		err = devm_request_irq(dev, pci_irq_vector(pdev, i),
+		err = devm_request_irq(dev, vmd->irqs[i].virq,
 				       vmd_irq, IRQF_NO_THREAD,
 				       vmd->name, &vmd->irqs[i]);
 		if (err)