Integrator PCI base dilemma

[Linus Walleij]

When trying to convert the Integrator/AP to use Device Tree
for the PCI bridge/hose I run into these two problems:

- Unable to assign vga_base early since this should be a virtual
  address assigned really early. If I sacrifice this and try to
  just remap the stuff, I still run into:

- Unable to ioremap the PCI memory and config window because
  it is 16 MiB big. (I guess this is the problem?)

Part of the code path is called from .map_io() and basically looks
like this:

int __init pci_v3_early_init(void)
{
	iotable_init(pci_v3_io_desc, ARRAY_SIZE(pci_v3_io_desc));
	vga_base = PCI_MEMORY_VADDR;
	pci_map_io_early(__phys_to_pfn(PHYS_PCI_IO_BASE));
	return 0;
}

The VGA console seems to be the sole user (unsure what
pci_map_io_early() is for), and we like to support VGA console.

The problem is that at this point at iomap the device tree is not yet
populated.

We can attempt to do it later but then the kernel hangs when
I try to remap the two 16MiB chunks for the non-prefetched
memory and the config window.

The iomem table looks like this:

/*
 * Static mappings for the PCIv3 bridge
 *
 * e8000000	40000000	PCI memory		PHYS_PCI_MEM_BASE	(max 512M)
 * ec000000	61000000	PCI config space	PHYS_PCI_CONFIG_BASE	(max 16M)
 * fee00000	60000000	PCI IO			PHYS_PCI_IO_BASE	(max 16M)
 */
static struct map_desc pci_v3_io_desc[] __initdata __maybe_unused = {
	{
		.virtual	= (unsigned long)PCI_MEMORY_VADDR,
		.pfn		= __phys_to_pfn(PHYS_PCI_MEM_BASE),
		.length		= SZ_16M,
		.type		= MT_DEVICE
	}, {
		.virtual	= (unsigned long)PCI_CONFIG_VADDR,
		.pfn		= __phys_to_pfn(PHYS_PCI_CONFIG_BASE),
		.length		= SZ_16M,
		.type		= MT_DEVICE
	}
};

Does anyone have any hints on how to get out of this need to have the
base addresses so early?

Or am I doing something wrong when I try to push in this map
later? I tried to just ioremap() them later but that doesn't
seem to work at all. Too big?

Yours,
Linus Walleij