Re: [PATCH 04/25] iommu/dma: Remove the flush_page callback

[Catalin Marinas]

On Tue, Apr 30, 2019 at 06:51:53AM -0400, Christoph Hellwig wrote:
> We now have a arch_dma_prep_coherent architecture hook that is used
> for the generic DMA remap allocator, and we should use the same
> interface for the dma-iommu code.
> 
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
> ---
>  arch/arm64/mm/dma-mapping.c | 8 +-------
>  drivers/iommu/dma-iommu.c   | 8 +++-----
>  include/linux/dma-iommu.h   | 3 +--
>  3 files changed, 5 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> index 674860e3e478..10a8852c8b6a 100644
> --- a/arch/arm64/mm/dma-mapping.c
> +++ b/arch/arm64/mm/dma-mapping.c
> @@ -104,12 +104,6 @@ arch_initcall(arm64_dma_init);
>  #include <linux/platform_device.h>
>  #include <linux/amba/bus.h>
>  
> -/* Thankfully, all cache ops are by VA so we can ignore phys here */
> -static void flush_page(struct device *dev, const void *virt, phys_addr_t phys)
> -{
> -	__dma_flush_area(virt, PAGE_SIZE);
> -}

Rather than removing, should this not become arch_dma_prep_coherent()?
With patch 2 selecting the corresponding Kconfig option, I think with
this patch you'd get a build error (haven't tried).

-- 
Catalin