Re: [PATCH RFC 22/35] dma-remap: drop nth_page() in dma_common_contiguous_remap()

Marek Szyprowski
2025-11-18T23:34:53Z

On 21.08.2025 22:06, David Hildenbrand wrote:
> dma_common_contiguous_remap() is used to remap an "allocated contiguous
> region". Within a single allocation, there is no need to use nth_page()
> anymore.
>
> Neither the buddy, nor hugetlb, nor CMA will hand out problematic page
> ranges.
>
> Cc: Marek Szyprowski <m.szyprowski@samsung.com>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
> kernel/dma/remap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
> index 9e2afad1c6152..b7c1c0c92d0c8 100644
> --- a/kernel/dma/remap.c
> +++ b/kernel/dma/remap.c
> @@ -49,7 +49,7 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
> if (!pages)
> return NULL;
> for (i = 0; i < count; i++)
> - pages[i] = nth_page(page, i);
> + pages[i] = page++;
> vaddr = vmap(pages, count, VM_DMA_COHERENT, prot);
> kvfree(pages);
>

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland