ARM/PCI: Replace pci_sys_data->align_resource with global function pointer

dw_pcie_host_init() creates the PCI host bridge with pci_common_init_dev(),
an ARM-specific function that supplies the ARM-specific pci_sys_data
structure as the PCI "sysdata". To use dw_pcie_host_init() on other
architectures, we will copy the internals of pci_common_init_dev() into
pcie-designware.c instead of calling it, and dw_pcie_host_init() will
supply the DesignWare pcie_port structure as "sysdata".

Most ARM "sysdata" users are specific to non-DesignWare host bridges;
they'll be unaffected because those bridges will continue to have the ARM
pci_sys_data. Most of the rest are ARM-generic functions called by
pci_common_init_dev(); these will be unaffected because dw_pcie_host_init()
will no longer call pci_common_init().

But the ARM pcibios_align_resource() can be called by the PCI core for any
bridge, so it can't depend on sysdata since it may be either pci_sys_data
or pcie_port.

Remove the pcibios_align_resource() dependency on sysdata by replacing the
pci_sys_data->align_resource pointer with a global function pointer.

This is less general (we can no longer have per-host bridge
align_resource() methods), but the pci_sys_data->align_resource pointer was
used only by Marvell (see mvebu_pcie_enable()), so this would only be a
problem if we had a system with a combination of Marvell and other host
bridges

[bhelgaas: changelog]
Signed-off-by: Gabriele Paoloni <[e-mail]>
Signed-off-by: Zhou Wang <[e-mail]>
Signed-off-by: Bjorn Helgaas <[e-mail]>
Acked-by: Pratyush Anand <[e-mail]>

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

···
 	u8		(*swizzle)(struct pci_dev *, u8 *);
 					/* IRQ mapping				*/
 	int		(*map_irq)(const struct pci_dev *, u8, u8);
-					/* Resource alignement requirements	*/
-	resource_size_t (*align_resource)(struct pci_dev *dev,
-					  const struct resource *res,
-					  resource_size_t start,
-					  resource_size_t size,
-					  resource_size_t align);
 	void		*private_data;	/* platform controller private data	*/
 };
 

arch/arm/kernel/bios32.c

···
 #include <asm/mach/pci.h>
 
 static int debug_pci;
+static resource_size_t (*align_resource)(struct pci_dev *dev,
+		  const struct resource *res,
+		  resource_size_t start,
+		  resource_size_t size,
+		  resource_size_t align) = NULL;
 
 /*
  * We can't use pci_get_device() here since we are
···
 		sys->busnr   = busnr;
 		sys->swizzle = hw->swizzle;
 		sys->map_irq = hw->map_irq;
-		sys->align_resource = hw->align_resource;
+		align_resource = hw->align_resource;
 		INIT_LIST_HEAD(&sys->resources);
 
 		if (hw->private_data)
···
 				resource_size_t size, resource_size_t align)
 {
 	struct pci_dev *dev = data;
-	struct pci_sys_data *sys = dev->sysdata;
 	resource_size_t start = res->start;
 
 	if (res->flags & IORESOURCE_IO && start & 0x300)
···
 
 	start = (start + align - 1) & ~(align - 1);
 
-	if (sys->align_resource)
-		return sys->align_resource(dev, res, start, size, align);
+	if (align_resource)
+		return align_resource(dev, res, start, size, align);
 
 	return start;
 }