Re: [PATCH 02/15] swiotlb: remove dma_mark_clean

[Tony Luck]

On Fri, Dec 7, 2018 at 11:08 AM Christoph Hellwig <hch@xxxxxx> wrote:
>
> Instead of providing a special dma_mark_clean hook just for ia64, switch
> ia64 to use the normal arch_sync_dma_for_cpu hooks instead.
>
> This means that we now also set the PG_arch_1 bit for pages in the
> swiotlb buffer, which isn't stricly needed as we will never execute code
> out of the swiotlb buffer, but otherwise harmless.

ia64 build based on arch/ia64/configs/zx1_defconfig now fails with undefined
symbols arch_dma_alloc and arch_dma_free (used by kernel/dma/direct.c).

This config doesn't define CONFIG_SWIOTLB, so we don't get the
benefit of the routines in arch/ia64/kernel/dma-mapping.c

-Tony