ARM: pci: add ->add_bus() and ->remove_bus() hooks to hw_pci

Some PCI drivers may need to adjust the pci_bus structure after it has
been allocated by the Linux PCI core. The PCI core allows
architectures to implement the pcibios_add_bus() and
pcibios_remove_bus() for this purpose. This commit therefore extends
the hw_pci and pci_sys_data structures of the ARM PCI core to allow
PCI drivers to register ->add_bus() and ->remove_bus() in hw_pci,
which will get called when a bus is added or removed from the system.

This will be used for example by the Marvell PCIe driver to connect a
particular PCI bus with its corresponding MSI chip to handle Message
Signaled Interrupts.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Daniel Price <daniel.price@gmail.com>
Tested-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/include/asm/mach/pci.h

@@ -36,6 +36,8 @@ struct hw_pci {
 					  resource_size_t start,
 					  resource_size_t size,
 					  resource_size_t align);
+	void		(*add_bus)(struct pci_bus *bus);
+	void		(*remove_bus)(struct pci_bus *bus);
 };
 
 /*
@@ -63,6 +65,8 @@ struct pci_sys_data {
 					  resource_size_t start,
 					  resource_size_t size,
 					  resource_size_t align);
+	void		(*add_bus)(struct pci_bus *bus);
+	void		(*remove_bus)(struct pci_bus *bus);
 	void		*private_data;	/* platform controller private data	*/
 };
 

arch/arm/kernel/bios32.c

@@ -363,6 +363,20 @@ void pcibios_fixup_bus(struct pci_bus *bus)
 }
 EXPORT_SYMBOL(pcibios_fixup_bus);
 
+void pcibios_add_bus(struct pci_bus *bus)
+{
+	struct pci_sys_data *sys = bus->sysdata;
+	if (sys->add_bus)
+		sys->add_bus(bus);
+}
+
+void pcibios_remove_bus(struct pci_bus *bus)
+{
+	struct pci_sys_data *sys = bus->sysdata;
+	if (sys->remove_bus)
+		sys->remove_bus(bus);
+}
+
 /*
  * Swizzle the device pin each time we cross a bridge.  If a platform does
  * not provide a swizzle function, we perform the standard PCI swizzling.
@@ -464,6 +478,8 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 		sys->swizzle = hw->swizzle;
 		sys->map_irq = hw->map_irq;
 		sys->align_resource = hw->align_resource;
+		sys->add_bus = hw->add_bus;
+		sys->remove_bus = hw->remove_bus;
 		INIT_LIST_HEAD(&sys->resources);
 
 		if (hw->private_data)