[PATCH v2 RESEND 1/2] ARM: Introduce ARM_L1_CACHE_SHIFT to define cache line size

Kirill A. Shutemov kirill at shutemov.name
Sat Sep 12 10:38:31 EDT 2009


On Sat, Sep 12, 2009 at 5:21 PM, Sergei Shtylyov
<sshtylyov at ru.mvista.com> wrote:
> Hello.
>
> Kirill A. Shutemov wrote:
>
>>>> Currently kernel believes that all ARM CPUs have L1_CACHE_SHIFT == 5.
>>>> It's not true at least for CPUs based on Cortex-A8.
>>>>
>>>> List of CPUs with cache line size != 32 should be expanded later.
>>>>
>>>> Signed-off-by: Kirill A. Shutemov <kirill at shutemov.name>
>>>> ---
>>>>  arch/arm/include/asm/cache.h |    2 +-
>>>>  arch/arm/mm/Kconfig          |    5 +++++
>>>>  2 files changed, 6 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/arch/arm/include/asm/cache.h b/arch/arm/include/asm/cache.h
>>>> index feaa75f..2ee7743 100644
>>>> --- a/arch/arm/include/asm/cache.h
>>>> +++ b/arch/arm/include/asm/cache.h
>>>> @@ -4,7 +4,7 @@
>>>>  #ifndef __ASMARM_CACHE_H
>>>>  #define __ASMARM_CACHE_H
>>>>  -#define L1_CACHE_SHIFT         5
>>>> +#define L1_CACHE_SHIFT         (CONFIG_ARM_L1_CACHE_SHIFT)
>>>>
>>>>
>>>
>>>  Parens not needed.
>>>
>>
>> You can write anything in your .config (like 2+3), so I think parens is
>> needed.
>>
>
>  You can -- but that won't be an integer option.

But kernel will be still compilable, but broken.

I think parens for defines from .config is a good practice.



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