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. Joerg