PCI: Ignore BAR updates on virtual functions

BugLink: http://bugs.launchpad.net/bugs/1625318

VF BARs are read-only zero, so updating VF BARs will not have any effect.
See the SR-IOV spec r1.1, sec 3.4.1.11.

We already ignore these updates because of 70675e0b ("PCI: Don't try to
restore VF BARs"); this merely restructures it slightly to make it easier
to split updates for standard and SR-IOV BARs.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
(cherry picked from commit 63880b23)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

drivers/pci/pci.c

@@ -519,10 +519,6 @@ static void pci_restore_bars(struct pci_dev *dev)
 {
 	int i;
 
-	/* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
-	if (dev->is_virtfn)
-		return;
-
 	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
 		pci_update_resource(dev, i);
 }

drivers/pci/setup-res.c

@@ -36,10 +36,9 @@ void pci_update_resource(struct pci_dev *dev, int resno)
 	enum pci_bar_type type;
 	struct resource *res = dev->resource + resno;
 
-	if (dev->is_virtfn) {
-		dev_warn(&dev->dev, "can't update VF BAR%d\n", resno);
+	/* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
+	if (dev->is_virtfn)
 		return;
-	}
 
 	/*
 	 * Ignore resources for unimplemented BARs and unused resource slots