Hi Joerg, On Wed, Jul 26, 2017 at 6:15 PM, Joerg Roedel <j...@8bytes.org> wrote: > On Tue, Jul 04, 2017 at 10:55:55PM +0900, Tomasz Figa wrote: >> Current implementation of __iommu_dma_alloc_pages() keeps adding >> __GFP_HIGHMEM to GFP flags regardless of whether other zone flags are >> already included in the incoming flags. If __GFP_DMA or __GFP_DMA32 is >> set at the same time as __GFP_HIGHMEM, the allocation fails due to >> invalid zone flag combination. >> >> Fix this by checking for __GFP_DMA and __GFP_DMA32 in incoming GFP flags >> and adding __GFP_HIGHMEM only if they are not present. >> >> Signed-off-by: Tomasz Figa <tf...@chromium.org> > > Isn't it better to mask out __GFP_DMA and __GFP_DMA32 in the allocation > flags and only take them into account for iova allocation? > > When the IOMMU re-maps the DMA to this memory it doesn't matter where it > is in system memory.
It's a platform specific knowledge and I'd say the generic helper is not where it should be decided. Please see my reply to Robin for v1 [1]. [1] https://patchwork.kernel.org/patch/9810921/ Best regards. Tomasz _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
