ACPI/PCI: PCI extended config _OSC support called when root bridge added

The _OSC capability OSC_EXT_PCI_CONFIG_SUPPORT is set when the root
bridge is added with pci_acpi_osc_support() if we can access PCI
extended config space.

This adds the function pci_ext_cfg_avail which returns true if we can
access PCI extended config space (offset greater than 0xff). It
currently only returns false if arch=x86 and raw_pci_ext_ops is not set
(which might happen if pci=nommcfg is set on the kernel command-line).

Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 62ddb73..9ab8509f 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -562,6 +562,14 @@
 		pcibios_disable_irq(dev);
 }
 
+int pci_ext_cfg_avail(struct pci_dev *dev)
+{
+	if (raw_pci_ext_ops)
+		return 1;
+	else
+		return 0;
+}
+
 struct pci_bus * __devinit pci_scan_bus_on_node(int busno, struct pci_ops *ops, int node)
 {
 	struct pci_bus *bus = NULL;