Re: [net-next PATCH RFC 05/26] arch/avr32: Add option to skip sync on DMA map

From: Hans-Christian Noren Egtvedt
Date: Mon Oct 24 2016 - 14:27:53 EST


Around Mon 24 Oct 2016 08:04:53 -0400 or thereabout, Alexander Duyck wrote:
> The use of DMA_ATTR_SKIP_CPU_SYNC was not consistent across all of the DMA
> APIs in the arch/arm folder. This change is meant to correct that so that
> we get consistent behavior.

Looks good (-:

> Cc: Haavard Skinnemoen <hskinnemoen@xxxxxxxxx>
> Cc: Hans-Christian Egtvedt <egtvedt@xxxxxxxxxxxx>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>

Acked-by: Hans-Christian Noren Egtvedt <egtvedt@xxxxxxxxxxxx>

> ---
> arch/avr32/mm/dma-coherent.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/avr32/mm/dma-coherent.c b/arch/avr32/mm/dma-coherent.c
> index 58610d0..54534e5 100644
> --- a/arch/avr32/mm/dma-coherent.c
> +++ b/arch/avr32/mm/dma-coherent.c
> @@ -146,7 +146,8 @@ static dma_addr_t avr32_dma_map_page(struct device *dev, struct page *page,
> {
> void *cpu_addr = page_address(page) + offset;
>
> - dma_cache_sync(dev, cpu_addr, size, direction);
> + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
> + dma_cache_sync(dev, cpu_addr, size, direction);
> return virt_to_bus(cpu_addr);
> }
>
> @@ -162,6 +163,10 @@ static int avr32_dma_map_sg(struct device *dev, struct scatterlist *sglist,
>
> sg->dma_address = page_to_bus(sg_page(sg)) + sg->offset;
> virt = sg_virt(sg);
> +
> + if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
> + continue;
> +
> dma_cache_sync(dev, virt, sg->length, direction);
> }
>
--
mvh
Hans-Christian Noren Egtvedt