[RFC PATCH v2] arm DMA: Fix allocation from CMA for coherent DMA

[Lorenzo Nava]

ping!

On Wed, Jun 3, 2015 at 7:15 PM, Lorenzo Nava <lorenx4 at gmail.com> wrote:
> This patch allows the use of CMA for DMA coherent memory allocation.
> At the moment if the input parameter "is_coherent" is set to true
> the allocation is not made using the CMA, which I think is not the
> desired behaviour.
>
> Signed-off-by: Lorenzo Nava <lorenx4 at xxxxxxxx>
> ---
> Changes in v2:
>  correct __arm_dma_free() according to __dma_alloc() allocation
> ---
>  arch/arm/mm/dma-mapping.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 7e7583d..15643b9 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -645,9 +645,9 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
>         size = PAGE_ALIGN(size);
>         want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs);
>
> -       if (is_coherent || nommu())
> +       if (nommu())
>                 addr = __alloc_simple_buffer(dev, size, gfp, &page);
> -       else if (!(gfp & __GFP_WAIT))
> +       else if (!is_coherent && !(gfp & __GFP_WAIT))
>                 addr = __alloc_from_pool(size, &page);
>         else if (!dev_get_cma_area(dev))
>                 addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller, want_vaddr);
> @@ -735,7 +735,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
>
>         size = PAGE_ALIGN(size);
>
> -       if (is_coherent || nommu()) {
> +       if (nommu()) {
>                 __dma_free_buffer(page, size);
>         } else if (__free_from_pool(cpu_addr, size)) {
>                 return;
> --
> 1.7.10.4
>