Re: 3.8-rc1 build failure with MIPS/SPARSEMEM

["Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>]

[-- Attachment #1: Type: text/plain, Size: 3400 bytes --]

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>
---
 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)
 {
-- 
1.8.0.2

-- 
 Kirill A. Shutemov

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]