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

Christoph Hellwig
2019-01-03T07:24:00Z

On Wed, Jan 02, 2019 at 01:53:33PM -0800, Tony Luck wrote:
> On Fri, Dec 7, 2018 at 11:08 AM Christoph Hellwig <hch@lst.de> 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

I think something like the patch below should fix it:

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index ccd56f5df8cd..8d7396bd1790 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -31,7 +31,7 @@ config IA64
select HAVE_MEMBLOCK_NODE_MAP
select HAVE_VIRT_CPU_ACCOUNTING
select ARCH_HAS_DMA_COHERENT_TO_PFN if SWIOTLB
- select ARCH_HAS_SYNC_DMA_FOR_CPU
+ select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB
select VIRT_TO_BUS
select ARCH_DISCARD_MEMBLOCK
select GENERIC_IRQ_PROBE