Subject: [PATCH] CMA: generalize CMA reserved area management functionality (fixup)

From: [email-masked] (Marek Szyprowski)
Date: Fri, 18 Jul 2014 09:33:16 +0200

Hello,

On 2014-07-18 00:06, Andrew Morton wrote:
> On Thu, 17 Jul 2014 11:36:07 +0200 Marek Szyprowski <[email-masked]> wrote:
>
>> MAX_CMA_AREAS is used by other subsystems (i.e. arch/arm/mm/dma-mapping.c),
>> so we need to provide correct definition even if CMA is disabled.
>> This patch fixes this issue.
>>
>> Reported-by: Sylwester Nawrocki <[email-masked]>
>> Signed-off-by: Marek Szyprowski <[email-masked]>
>> ---
>>   include/linux/cma.h | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/include/linux/cma.h b/include/linux/cma.h
>> index 9a18a2b1934c..c077635cad76 100644
>> --- a/include/linux/cma.h
>> +++ b/include/linux/cma.h
>> @@ -5,7 +5,11 @@
>>    * There is always at least global CMA area and a few optional
>>    * areas configured in kernel .config.
>>    */
>> +#ifdef CONFIG_CMA
>>   #define MAX_CMA_AREAS	(1 + CONFIG_CMA_AREAS)
>> +#else
>> +#define MAX_CMA_AREAS	(0)
>> +#endif
>>   
>>   struct cma;
> Joonsoo already fixed this up, a bit differently:
> http://ozlabs.org/~akpm/mmots/broken-out/cma-generalize-cma-reserved-area-management-functionality-fix.patch
>
> Which approach makes more sense?

CMA_AREAS depends on CMA being enabled, so both approaches works exactly
the same way. Please keep Joonsoo's patch and just ignore mine to avoid
confusing others by disappearing patches. I'm sorry that I've missed it
before sending mine.

> From: Joonsoo Kim <[email-masked]>
> Subject: CMA: fix ARM build failure related to MAX_CMA_AREAS definition
>
> If CMA is disabled, CONFIG_CMA_AREAS isn't defined so compile error
> happens. To fix it, define MAX_CMA_AREAS if CONFIG_CMA_AREAS
> isn't defined.
>
> Signed-off-by: Joonsoo Kim <[email-masked]>
> Reported-by: Stephen Rothwell <[email-masked]>
> Signed-off-by: Andrew Morton <[email-masked]>
> ---
>
>   include/linux/cma.h |    6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff -puN include/linux/cma.h~cma-generalize-cma-reserved-area-management-functionality-fix include/linux/cma.h
> --- a/include/linux/cma.h~cma-generalize-cma-reserved-area-management-functionality-fix
> +++ a/include/linux/cma.h
> @@ -5,8 +5,14 @@
>    * There is always at least global CMA area and a few optional
>    * areas configured in kernel .config.
>    */
> +#ifdef CONFIG_CMA_AREAS
>   #define MAX_CMA_AREAS	(1 + CONFIG_CMA_AREAS)
>   
> +#else
> +#define MAX_CMA_AREAS	(0)
> +
> +#endif
> +
>   struct cma;
>   
>   extern phys_addr_t cma_get_base(struct cma *cma);
> _

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland