Re: [PATCH 19/31] arc: handle page-less SG entries

Vineet Gupta
2015-08-12T10:28:55Z

On Wednesday 12 August 2015 12:39 PM, Christoph Hellwig wrote:
> Make all cache invalidation conditional on sg_has_page() and use
> sg_phys to get the physical address directly.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

With a minor nit below.

Acked-by: Vineet Gupta <vgupta@synopsys.com>

> ---
> arch/arc/include/asm/dma-mapping.h | 26 +++++++++++++++++++-------
> 1 file changed, 19 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arc/include/asm/dma-mapping.h b/arch/arc/include/asm/dma-mapping.h
> index 2d28ba9..42eb526 100644
> --- a/arch/arc/include/asm/dma-mapping.h
> +++ b/arch/arc/include/asm/dma-mapping.h
> @@ -108,9 +108,13 @@ dma_map_sg(struct device *dev, struct scatterlist *sg,
> struct scatterlist *s;
> int i;
>
> - for_each_sg(sg, s, nents, i)
> - s->dma_address = dma_map_page(dev, sg_page(s), s->offset,
> - s->length, dir);
> + for_each_sg(sg, s, nents, i) {
> + if (sg_has_page(s)) {
> + _dma_cache_sync((unsigned long)sg_virt(s), s->length,
> + dir);
> + }
> + s->dma_address = sg_phys(s);
> + }
>
> return nents;
> }
> @@ -163,8 +167,12 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist, int nelems,
> int i;
> struct scatterlist *sg;
>
> - for_each_sg(sglist, sg, nelems, i)
> - _dma_cache_sync((unsigned int)sg_virt(sg), sg->length, dir);
> + for_each_sg(sglist, sg, nelems, i) {
> + if (sg_has_page(sg)) {
> + _dma_cache_sync((unsigned int)sg_virt(sg), sg->length,
> + dir);
> + }
> + }
> }
>
> static inline void
> @@ -174,8 +182,12 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist,
> int i;
> struct scatterlist *sg;
>
> - for_each_sg(sglist, sg, nelems, i)
> - _dma_cache_sync((unsigned int)sg_virt(sg), sg->length, dir);
> + for_each_sg(sglist, sg, nelems, i) {
> + if (sg_has_page(sg)) {
> + _dma_cache_sync((unsigned int)sg_virt(sg), sg->length,
> + dir);

For consistency, could u please fix the left alignment of @dir above - another tab
perhaps ?

> + }
> + }
> }
>
> static inline int dma_supported(struct device *dev, u64 dma_mask)