PCI: hv: Rework MSI handling

Replace the about to vanish iterators and make use of the filtering. Take
the descriptor lock around the iterators.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NMichael Kelley <mikelley@microsoft.com>
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211206210748.629363944@linutronix.de

drivers/pci/controller/pci-hyperv.c

@@ -3445,18 +3445,23 @@ static int hv_pci_suspend(struct hv_device *hdev)
 
 static int hv_pci_restore_msi_msg(struct pci_dev *pdev, void *arg)
 {
-	struct msi_desc *entry;
 	struct irq_data *irq_data;
+	struct msi_desc *entry;
+	int ret = 0;
 
-	for_each_pci_msi_entry(entry, pdev) {
+	msi_lock_descs(&pdev->dev);
+	msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) {
 		irq_data = irq_get_irq_data(entry->irq);
-		if (WARN_ON_ONCE(!irq_data))
-			return -EINVAL;
+		if (WARN_ON_ONCE(!irq_data)) {
+			ret = -EINVAL;
+			break;
+		}
 
 		hv_compose_msi_msg(irq_data, &entry->msg);
 	}
+	msi_unlock_descs(&pdev->dev);
 
-	return 0;
+	return ret;
 }
 
 /*