powerpc/pci: Add pcibios_disable_device() hook

This adds a hook into the powerpc pci code for pci_disable_device() calls.  The
generic code already provides a weak pcibios_disable_device() symbol, so we
just need to provide our own in powerpc and it'll get picked up.

This is passed directly to the phb controller ops, provided one exists.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/pci-bridge.h

@@ -27,6 +27,8 @@ struct pci_controller_ops {
 	 * allow assignment/enabling of the device. */
 	bool		(*enable_device_hook)(struct pci_dev *);
 
+	void		(*disable_device)(struct pci_dev *);
+
 	void		(*release_device)(struct pci_dev *);
 
 	/* Called during PCI resource reassignment */

arch/powerpc/kernel/pci-common.c

@@ -1490,6 +1490,14 @@ int pcibios_enable_device(struct pci_dev *dev, int mask)
 	return pci_enable_resources(dev, mask);
 }
 
+void pcibios_disable_device(struct pci_dev *dev)
+{
+	struct pci_controller *phb = pci_bus_to_host(dev->bus);
+
+	if (phb->controller_ops.disable_device)
+		phb->controller_ops.disable_device(dev);
+}
+
 resource_size_t pcibios_io_space_offset(struct pci_controller *hose)
 {
 	return (unsigned long) hose->io_base_virt - _IO_BASE;