Re: [PATCH] Fix virt_to_phys() warnings

[Ralf Baechle <ralf@linux-mips.org>]

On Thu, Jul 02, 2009 at 09:07:46AM +0200, Andi Kleen wrote:
> From: Andi Kleen <andi@firstfloor.org>
> Date: Thu, 02 Jul 2009 09:07:46 +0200
> To: Andrew Morton <akpm@linux-foundation.org>
> Cc: Kevin Cernekee <cernekee@gmail.com>, linux-kernel@vger.kernel.org,
> 	Ralf Baechle <ralf@linux-mips.org>
> Subject: Re: [PATCH] Fix virt_to_phys() warnings
> Content-Type: text/plain; charset=us-ascii
> 
> Andrew Morton <akpm@linux-foundation.org> writes:
> >
> > #define virt_to_page(kaddr)        pfn_to_page(PFN_DOWN(virt_to_phys(kaddr)))
> >
> > thereby passing an `unsigned long' where a void* was expected.
> >
> >
> > So perhaps something along these lines:
> 
> I'm not quite sure it's the case on MIPS, but I remember on x86 one of
> the reasons this was done as a macro was to avoid a include dependency
> loop with struct page.

The MIPS <asm/page.h> uses a forward declaration for the same reason since
a very long time.  These days struct page is defined in <linux/mm_types.h>
but that file needs pgprot_t (which is defined in <asm/page.h> ...) to be
defined first so can't be included from the to of page.h.

  Ralf