Subject: [Linaro-acpi] [RFC PATCH 3/4] arm64, acpi, pci: Add arch specific functions for mmconfig driver.

From: [email-masked] (Arnd Bergmann)
Date: Fri, 07 Nov 2014 15:54:09 +0100

On Friday 07 November 2014 15:39:32 Tomasz Nowicki wrote:
> On 07.11.2014 15:12, Arnd Bergmann wrote:
> > On Friday 07 November 2014 14:27:55 Tomasz Nowicki wrote:
> >> These calls allow to map/unmap PCI config space ranges (which are specified in
> >> MMCFG ACPI table).
> >>
> >> Signed-off-by: Tomasz Nowicki <[email-masked]>
> >>
> >
> > Nothing in this patch looks arm64 specific, and most of it looks like a
> > copy of the x86 code.
> 
> Yes, most of the logic was borrowed from mmconfig_64.c file, 
> mmconfig_32.c looks differently, though. It is not simple to merge them 
> both. IMO, we have two choices:
> 1. Refactor and move mmconfig_64.c out of x86 to e.g. drivers/acpi/ and 
> let it be default.
> 2. Stay with solution presented in this patch.
> 3. Thoughts ?

If the code is generic, it should be shared with as many architectures as
possible. Moving the x86-64 implementation to drivers/acpi/ would immediately
let you share it with two out of the four architectures (x86-64 and arm64,
but not x86-32 and ia64) as well as any potential other architectures that
might implement ACPI in the future.

	Arnd