PCI/MSI: Let core code free MSI descriptors

Set the domain info flag which tells the core code to free the MSI
descriptors from msi_domain_free_irqs() and add an explicit call to the
core function into the legacy code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211206210748.089085131@linutronix.de

drivers/pci/msi/irqdomain.c

@@ -171,7 +171,8 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
 		pci_msi_domain_update_chip_ops(info);
 
-	info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS;
+	info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS |
+		       MSI_FLAG_FREE_MSI_DESCS;
 	if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
 		info->flags |= MSI_FLAG_MUST_REACTIVATE;
 

drivers/pci/msi/legacy.c

@@ -80,4 +80,5 @@ void pci_msi_legacy_teardown_msi_irqs(struct pci_dev *dev)
 {
 	msi_device_destroy_sysfs(&dev->dev);
 	arch_teardown_msi_irqs(dev);
+	msi_free_msi_descs(&dev->dev);
 }

drivers/pci/msi/msi.c

@@ -224,22 +224,8 @@ EXPORT_SYMBOL_GPL(pci_write_msi_msg);
 
 static void free_msi_irqs(struct pci_dev *dev)
 {
-	struct list_head *msi_list = dev_to_msi_list(&dev->dev);
-	struct msi_desc *entry, *tmp;
-	int i;
-
-	for_each_pci_msi_entry(entry, dev)
-		if (entry->irq)
-			for (i = 0; i < entry->nvec_used; i++)
-				BUG_ON(irq_has_action(entry->irq + i));
-
 	pci_msi_teardown_msi_irqs(dev);
 
-	list_for_each_entry_safe(entry, tmp, msi_list, list) {
-		list_del(&entry->list);
-		free_msi_entry(entry);
-	}
-
 	if (dev->msix_base) {
 		iounmap(dev->msix_base);
 		dev->msix_base = NULL;