Re: kbuild now support arch/$ARCH/include - time for ARCHs to convert

[Greg Ungerer <gerg@snapgear.com>]

Hi Geert,

Geert Uytterhoeven wrote:
> On Fri, 1 Aug 2008, Greg Ungerer wrote:
>> Sam Ravnborg wrote:
>>> On Wed, Jul 30, 2008 at 04:49:08PM +1000, Greg Ungerer wrote:
>>>> Sam Ravnborg wrote:
>>>>> The traditional location of the arch specific Makefiles
>>>>> has been at:
>>>>>
>>>>> 	include/asm-$ARCH
>>>>>
>>>>> But as suggested by several people over time and lately
>>>>> by Linus in the following post:
>>>>> http://kerneltrap.org/mailarchive/linux-kernel/2008/5/21/1903924
>>>>>
>>>>> is is suggested to move the arch specific files under arch/
>>>>> and for the header files this is arch/$ARCH/include.
>>>>>
>>>>> So I have hacked up support for this in kbuild so
>>>>> for the simpler cases a simple move of header files as
>>>>> in:
>>>>> 	git mv include/asm-$ARCH arch/$ARCH/include/asm
>>>>>
>>>>> is enough.
>>>>>
>>>>> If Linus will accept it then I think -rc1 is a perfect
>>>>> time to do it as people has less stuff pending touching
>>>>> the header files that are moved.
>>>>> Validation is easy - does the usual configs build?
>>>>>
>>>>> For the archs that plays games with symlinks this is a
>>>>> splendid opportunity to get rid af these.
>>>>> The receipe is simple:
>>>>> Use 	KBUILD_CFLAGS += -Iarch/$ARCH/include/$CPU
>>>>>
>>>>> to select the CPU and then do a copy of the header files
>>>>> like this:
>>>>>
>>>>> 	git mv include/asm-$ARCH/$CPU arch/$ARCH/include/$CPU/cpu
>>>>>
>>>>> Then the code can continue to use:
>>>>>
>>>>> 	#include <cpu/foo.h>
>>>>>
>>>>> I already converted sparc to use arch/sparc/include -
>>>>> while I merged the header files for sparc and sparc64.
>>>>> This change is already upstream.
>>>>>
>>>>> And for SH I posted a receipe which you can read here:
>>>>> http://lkml.org/lkml/2008/7/28/83
>>>>>
>>>>> It is SH specific but anyway pretty generic.
>>>>>
>>>>> I am limited in time and resources at the moment but I
>>>>> would be glad to help out as time permits should there
>>>>> be any questions.
>>>> I just tried moving the include/asm-m68knommu directory
>>>> to arch/m68knommu/include/asm and it all worked fine.
>>>> Clean compile first go :-)  Nice.  (As noted
>>>> asm-offsets.h was still generated in incldue/asm-m68knommu
>>>> afterwards though).
>>>>
>>>> So what is the status, should I prepare git/patch
>>>> for Linus?
>>> Yes please do so.
>> The move change can be pulled from:
>>
>> git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu.git for-linus
>>
>> If there is no complaints I'll send Linus a pull request in a
>> couple of days time.
> 
> I did:
> 
>     mkdir arch/m68k/include
>     mv include/asm-m68k arch/m68k/include/asm
> 
> and m68k still builds fine (I applied Stephen's patch for the
> asm-sparc inclusion problem for Sun 3/3x first, of course).
> 
> As (a) I'm not using git (yet) for merging with Linus, and (b) this will
> cause some breakage in the m68knommu tree anyway, perhaps it's easiest if Greg
> takes care of it in m68knommu.git?
> 
> Greg, is that OK for you?

Yep, I will do that.


> You can add my Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
> 
> There seem to be 3 classes of m68knommu header files:
>   1. Plain files (some of them may be (nearly) identical copies of the
>      m68k variants,
>   2. Files that just include the m68k variant,
>   3. Files that include the m68k variant and do something more (pci.h and
>      setup.h).
> 
> Since I don't think we want to do the m68k/m68knommu merge right now
> (Sorry Arnd, I'll keep your script in mind anyway!), the simplest way is to:
>   - Remove all files from class 2, and add to the Makefile:
> 
> 	ccflags-y += -Iarch/m68k/include
> 
>   - Include verbatim the contents of the m68k variant for class 3, cfr.
>     Stephen patch for the asm-sparc inclusion problem for Sun 3/3x).
> 
> Do you agree?

That sounds like a good approach.

Regards
Greg



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