3.8-rc4 build regression (was: Re: 3.8-rc1 build failure with MIPS/SPARSEMEM)

[David Daney <ddaney.cavm@gmail.com>]

Linus, Andrew and Ralf,

3.8 doesn't build on MIPS any more.

Please consider this patch ...

On 12/25/2012 04:34 PM, Kirill A. Shutemov wrote:
> On Sat, Dec 22, 2012 at 02:27:57PM +0200, Aaro Koskinen wrote:
>> Hi,
>>
>> It looks like commit 816422ad76474fed8052b6f7b905a054d082e59a
>> (asm-generic, mm: pgtable: consolidate zero page helpers) broke
>> MIPS/SPARSEMEM build in 3.8-rc1:
>>
>>    CHK     include/generated/uapi/linux/version.h
>>    CHK     include/generated/utsrelease.h
>>    Checking missing-syscalls for N32
>>    CC      arch/mips/kernel/asm-offsets.s
>> In file included from /home/aaro/git/linux/arch/mips/include/asm/pgtable.h:388:0,
>>                   from include/linux/mm.h:44,
>>                   from arch/mips/kernel/asm-offsets.c:14:
>> include/asm-generic/pgtable.h: In function 'my_zero_pfn':
>> include/asm-generic/pgtable.h:462:9: error: implicit declaration of function 'page_to_section' [-Werror=implicit-function-declaration]
>> In file included from arch/mips/kernel/asm-offsets.c:14:0:
>> include/linux/mm.h: At top level:
>> include/linux/mm.h:708:29: error: conflicting types for 'page_to_section'
>> In file included from /home/aaro/git/linux/arch/mips/include/asm/pgtable.h:388:0,
>>                   from include/linux/mm.h:44,
>>                   from arch/mips/kernel/asm-offsets.c:14:
>> include/asm-generic/pgtable.h:462:9: note: previous implicit declaration of 'page_to_section' was here
>> cc1: some warnings being treated as errors
>> make[1]: *** [arch/mips/kernel/asm-offsets.s] Error 1
>> make: *** [archprepare] Error 2
>
> The patch below works for me. Could you try?
>
>  From a123a406fdc3aee7ca0eae04b6b4a231872dbb51 Mon Sep 17 00:00:00 2001
> From: "Kirill A. Shutemov" <kirill@shutemov.name>
> Date: Wed, 26 Dec 2012 03:19:55 +0300
> Subject: [PATCH] asm-generic, mm: pgtable: convert my_zero_pfn() to macros to
>   fix build
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
>
> On MIPS if SPARSEMEM is enabled we've got this:
>
> In file included from /home/kas/git/public/linux/arch/mips/include/asm/pgtable.h:552,
>                   from include/linux/mm.h:44,
>                   from arch/mips/kernel/asm-offsets.c:14:
> include/asm-generic/pgtable.h: In function ‘my_zero_pfn’:
> include/asm-generic/pgtable.h:466: error: implicit declaration of function ‘page_to_section’
> In file included from arch/mips/kernel/asm-offsets.c:14:
> include/linux/mm.h: At top level:
> include/linux/mm.h:738: error: conflicting types for ‘page_to_section’
> include/asm-generic/pgtable.h:466: note: previous implicit declaration of ‘page_to_section’ was here
>
> Due header files inter-dependencies, the only way I see to fix it is
> convert my_zero_pfn() for __HAVE_COLOR_ZERO_PAGE to macros.
>
> Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

I arrived (independently) at the identical solution.

Acked-by: David Daney <david.daney@cavium.com>


> ---
>   include/asm-generic/pgtable.h | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
> index 701beab..5cf680a 100644
> --- a/include/asm-generic/pgtable.h
> +++ b/include/asm-generic/pgtable.h
> @@ -461,10 +461,8 @@ static inline int is_zero_pfn(unsigned long pfn)
>   	return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
>   }
>
> -static inline unsigned long my_zero_pfn(unsigned long addr)
> -{
> -	return page_to_pfn(ZERO_PAGE(addr));
> -}
> +#define my_zero_pfn(addr)	page_to_pfn(ZERO_PAGE(addr))
> +
>   #else
>   static inline int is_zero_pfn(unsigned long pfn)
>   {
>