PCI: hv: Allocate a named fwnode instead of an address-based one

To allocate its fwnode that is then used to allocate an irqdomain,
the driver uses irq_domain_alloc_fwnode(), passing it a VA as an
identifier. This is a rather bad idea, as this address ends up
published in debugfs (and we want to move away from VAs there
anyway).

Instead, let's allocate a named fwnode by using the device GUID as
an identifier. It is allegedly unique, and can be traced back to
the original device.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>

drivers/pci/controller/pci-hyperv.c

@@ -2521,6 +2521,7 @@ static int hv_pci_probe(struct hv_device *hdev,
 			const struct hv_vmbus_device_id *dev_id)
 {
 	struct hv_pcibus_device *hbus;
+	char *name;
 	int ret;
 
 	/*
@@ -2589,7 +2590,14 @@ static int hv_pci_probe(struct hv_device *hdev,
 		goto free_config;
 	}
 
-	hbus->sysdata.fwnode = irq_domain_alloc_fwnode(hbus);
+	name = kasprintf(GFP_KERNEL, "%pUL", &hdev->dev_instance);
+	if (!name) {
+		ret = -ENOMEM;
+		goto unmap;
+	}
+
+	hbus->sysdata.fwnode = irq_domain_alloc_named_fwnode(name);
+	kfree(name);
 	if (!hbus->sysdata.fwnode) {
 		ret = -ENOMEM;
 		goto unmap;