powerpc/iommu: Support "hybrid" iommu/direct DMA ops for coherent_mask < dma_mask
This patch adds the ability to the DMA direct ops to fallback to the IOMMU
ops for coherent alloc/free if the coherent mask of the device isn't
suitable for accessing the direct DMA space and the device also happens
to have an active IOMMU table.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5ef2711..fe2f2c5 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -82,6 +82,9 @@
bool
default y
+config ARCH_HAS_DMA_SET_COHERENT_MASK
+ bool
+
config PPC
bool
default y
@@ -155,6 +158,7 @@
select HAVE_PERF_EVENTS_NMI if PPC64
select EDAC_SUPPORT
select EDAC_ATOMIC_SCRUB
+ select ARCH_HAS_DMA_SET_COHERENT_MASK
config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN