dma-mapping: provide a better default ->get_required_mask
Most dma_map_ops instances are IOMMUs that work perfectly fine in 32-bits
of IOVA space, and the generic direct mapping code already provides its
own routines that is intelligent based on the amount of memory actually
present. Wire up the dma-direct routine for the ARM direct mapping code
as well, and otherwise default to the constant 32-bit mask. This way
we only need to override it for the occasional odd IOMMU that requires
64-bit IOVA support, or IOMMU drivers that are more efficient if they
can fall back to the direct mapping.
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index f72c487..a6ac371 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -680,6 +680,7 @@ static const struct dma_map_ops gart_dma_ops = {
.mmap = dma_common_mmap,
.get_sgtable = dma_common_get_sgtable,
.dma_supported = dma_direct_supported,
+ .get_required_mask = dma_direct_get_required_mask,
};
static void gart_iommu_shutdown(void)