On 04/16/2014 05:05 PM, Michal Hocko wrote:
> On Tue 15-04-14 09:21:30, Chen Gang wrote:
> [...]
>> diff --git a/arch/unicore32/include/asm/io.h
>> b/arch/unicore32/include/asm/io.h
>> index 39decb6..ae327e4 100644
>> --- a/arch/unicore32/include/asm/io.h
>> +++ b/arch/unicore32/include/asm/io.h
>
> There is already quite a mess where the function is defined. We have it
> in mmap.c, init.c, mem.c and s390 defines it in page.h. Is there any
> good reason to add yet another place and pull in additional header files
> dependencies?
It is short enough to be as static inline function. It also can bypass
choosing which ".c" file contents the implementation (arm{64} declare it
in "io.h").
So recommend devmem_is_allowed() in arm{64} are also "static inline".
Hmm... is it possible to move the static inline implementation from
"io.h" to "page.h", since all other archs declare or implement in
"page.h" related header file.
> Why not follow x86 here? Or even better git rid of the code duplication
> and provide generic implementation which different arches can reuse and
> extend? arm{64}, unicore32 seem to be identical. Powepc and x86 have an
> additional test to the core one used by the above arches. Only tile
> seems to be be doing something completely different.
>
For me, need not put it in 'asm-generic':
- 9/29 archs need it, so at present, it is not generic enough.
- most of them are different, which hard to find generic one.
- frv and m32r same, but different with others.
- arm{64} and unicore32 same, but different with others.
- powerpc, s390, tile, and x86 are different with each other.
If we are sure most new archs will support devmem_is_allowed(), and at
least, 40% are the same, we can continue to consider about whether put
it in 'asm-generic' or not.
Altogether, for me, let the related declaration/implementation in
"page.h" or related header file will be fine, at least present, it is
not need to put it in 'asm-generic'.
[...]
Thanks.
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
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