Re: [PATCH] m68k/m68knommu: merge MMU and non-MMU string.h

[Greg Ungerer <gerg@snapgear.com>]

Hi Geert,

Geert Uytterhoeven wrote:
> On Fri, Sep 10, 2010 at 06:36, Greg Ungerer <gerg@snapgear.com> wrote:
>> Geert Uytterhoeven wrote:
>>> On Wed, Sep 8, 2010 at 13:43, Greg Ungerer <gerg@snapgear.com> wrote:
>>>> On 08/09/10 06:35, Geert Uytterhoeven wrote:
>>>>> Now I see:
>>>>>
>>>>> | arch/m68k/kernel/entry.S: Assembler messages:
>>>>> | arch/m68k/kernel/entry.S:56: Error: can't resolve `0' {*ABS* section}
>>>>> - `THREAD_SIZE' {*UND* section}
>>>>> | arch/m68k/kernel/entry.S:64: Error: can't resolve `0' {*UND* section}
>>>>> - `THREAD_SIZE' {*UND* section}
>>>>> | arch/m68k/kernel/entry.S:119: Error: can't resolve `0' {*UND* section}
>>>>> - `THREAD_SIZE' {*UND* section}
>>>>> | arch/m68k/kernel/entry.S:203: Error: can't resolve `0' {*UND* section}
>>>>> - `THREAD_SIZE' {*UND* section}
>>>>> | arch/m68k/kernel/entry.S:236: Error: can't resolve `0' {*UND* section}
>>>>> - `THREAD_SIZE' {*UND* section}
>>>>> | arch/m68k/kernel/entry.S:257: Error: can't resolve `0' {*UND* section}
>>>>> - `THREAD_SIZE' {*UND* section}
>>>>>
>>>>> this is expanded from `GET_CURRENT'.
>>>> Just a thought, is it enough to include thread_info.h inside entry_mm.h?
>>> No, because <asm/thread_info.h> is no longer ASSEMBLY-clean, as it
>>> includes
>>> <asm/current.h>, which is C-only.
>>> The #include <asm/current.h> in there used to be protected by #ifndef
>>> ASSEMBLY.
>>> If I move that include up just above the definition of struct thread_info,
>>> <asm/thread_info.h> is ASSEMBLY-clean again.
>>>
>>> However, just including <asm/thread_info.h> from <asm/entry_mm.h> causes
>>> other
>>> problems for the C part, as <asm/thread_info.h> needs the definition of
>>> struct
>>> restart_block in <linux/thread_info.h>. And <linux/thread_info.h> is
>>> definitely
>>> not ASSEMBLY-clean.
>>>
>>> So I came up with the patch (white-space damaged due to the GMail web
>>> interface)
>>> below. Note that this changes the behavior for m68knommu, which didn't
>>> include
>>> <asm/current.h> from <asm/thread_info.h> before. I hope it doesn't hurt...
>> Unfortunately that breaks the m68knommu build:
>>
>> /home/gerg/new-wave.2635/linux-2.6.x.git/arch/m68k/include/asm/current.h: In
>> function ‘get_current’:
>> /home/gerg/new-wave.2635/linux-2.6.x.git/arch/m68k/include/asm/current.h:21:
>> error: implicit declaration of function ‘current_thread_info’
>> ...
>>
>> If we just wrap the include of asm/current.h with its own "#ifndef
>> __ASSEMBLY__", instead of moving it from above struct thread_info,
>> is that better for you?
> 
> Builds fine, too.

Ok, thanks. I'll generate a new patch based on this.

Regards
Greg



>>> diff --git a/arch/m68k/include/asm/entry_mm.h
>>> b/arch/m68k/include/asm/entry_mm.h
>>> index 6f70823..73b8c8f 100644
>>> --- a/arch/m68k/include/asm/entry_mm.h
>>> +++ b/arch/m68k/include/asm/entry_mm.h
>>> @@ -3,6 +3,9 @@
>>>
>>>  #include <asm/setup.h>
>>>  #include <asm/page.h>
>>> +#ifdef __ASSEMBLY__
>>> +#include <asm/thread_info.h>
>>> +#endif
>>>
>>>  /*
>>>  * Stack layout in 'ret_from_exception':
>>> diff --git a/arch/m68k/include/asm/thread_info.h
>>> b/arch/m68k/include/asm/thread_info.h
>>> index f28775e..aec5eff 100644
>>> --- a/arch/m68k/include/asm/thread_info.h
>>> +++ b/arch/m68k/include/asm/thread_info.h
>>> @@ -22,6 +22,8 @@
>>>
>>>  #ifndef __ASSEMBLY__
>>>
>>> +#include <asm/current.h>
>>> +
>>>  struct thread_info {
>>>        struct task_struct      *task;          /* main task structure */
>>>        unsigned long           flags;
>>> @@ -49,8 +51,6 @@ struct thread_info {
>>>
>>>  #ifdef CONFIG_MMU
>>>
>>> -#include <asm/current.h>
>>> -
>>>  #ifdef ASM_OFFSETS_C
>>>  #define task_thread_info(tsk)  ((struct thread_info *) NULL)
>>>  #else
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
> 


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