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

Andrew Morton
2014-07-17T22:06:15Z

On Thu, 17 Jul 2014 11:36:07 +0200 Marek Szyprowski <m.szyprowski@samsung.com> 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 <s.nawrocki@samsung.com>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
> 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?

From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
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 <iamjoonsoo.kim@lge.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

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);
_