PCI: Add pci_set_acpi_fwnode() to set ACPI_COMPANION

Move the existing logic from acpi_pci_bridge_d3() to a separate function
pci_set_acpi_fwnode() to set the ACPI fwnode.  No functional change
intended.

Link: https://lore.kernel.org/r/20210817180500.1253-7-ameynarkhede03@gmail.com
Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>

drivers/pci/pci-acpi.c

@@ -934,6 +934,13 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 
 static struct acpi_device *acpi_pci_find_companion(struct device *dev);
 
+void pci_set_acpi_fwnode(struct pci_dev *dev)
+{
+	if (!ACPI_COMPANION(&dev->dev) && !pci_dev_is_added(dev))
+		ACPI_COMPANION_SET(&dev->dev,
+				   acpi_pci_find_companion(&dev->dev));
+}
+
 static bool acpi_pci_bridge_d3(struct pci_dev *dev)
 {
 	const struct fwnode_handle *fwnode;
@@ -945,11 +952,8 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
 		return false;
 
 	/* Assume D3 support if the bridge is power-manageable by ACPI. */
+	pci_set_acpi_fwnode(dev);
 	adev = ACPI_COMPANION(&dev->dev);
-	if (!adev && !pci_dev_is_added(dev)) {
-		adev = acpi_pci_find_companion(&dev->dev);
-		ACPI_COMPANION_SET(&dev->dev, adev);
-	}
 
 	if (adev && acpi_device_power_manageable(adev))
 		return true;

drivers/pci/pci.h

@@ -707,7 +707,9 @@ static inline int pci_aer_raw_clear_status(struct pci_dev *dev) { return -EINVAL
 #ifdef CONFIG_ACPI
 int pci_acpi_program_hp_params(struct pci_dev *dev);
 extern const struct attribute_group pci_dev_acpi_attr_group;
+void pci_set_acpi_fwnode(struct pci_dev *dev);
 #else
+static inline void pci_set_acpi_fwnode(struct pci_dev *dev) {}
 static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
 {
 	return -ENODEV;