Re: [PATCH] Remove GFP_DMA and GFP_DMA32 from flags before passing it into kmalloc.

[Catalin Marinas <catalin.marinas@arm.com>]

On 27 Sep 2014, at 16:09, Miles MH Chen <orca.chen@gmail.com> wrote:
> Signed-off-by: Min-Hua Chen <orca.chen@gmail.com>
> ---
>  arch/arm64/mm/dma-mapping.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> index 4164c5a..273cf6d 100644
> --- a/arch/arm64/mm/dma-mapping.c
> +++ b/arch/arm64/mm/dma-mapping.c
> @@ -103,7 +103,8 @@ static void *__dma_alloc_noncoherent(struct device *dev, size_t size,
>      ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
>      if (!ptr)
>          goto no_mem;
> -    map = kmalloc(sizeof(struct page *) << order, flags & ~GFP_DMA);
> +    map = kmalloc(sizeof(struct page *) << order,
> +                    flags & ~(GFP_DMA | GFP_DMA32));

Do you have an explanation on why this is needed (and such explanation
should also be included in the commit log)? We don’t use ZONE_DMA32 on
arm64 (we did initially but it was for the wrong reasons).

Thanks,

Catalin