powerpc: Add support for swiotlb on 32-bit
This patch includes the basic infrastructure to use swiotlb
bounce buffering on 32-bit powerpc. It is not yet enabled on
any platforms. Probably the most interesting bit is the
addition of addr_needs_map to dma_ops - we need this as
a dma_op because the decision of whether or not an addr
can be mapped by a device is device-specific.
Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ff75539..93a6189 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -300,9 +300,19 @@
config IOMMU_HELPER
def_bool PPC64
+config SWIOTLB
+ bool "SWIOTLB support"
+ default n
+ select IOMMU_HELPER
+ ---help---
+ Support for IO bounce buffering for systems without an IOMMU.
+ This allows us to DMA to the full physical address space on
+ platforms where the size of a physical address is larger
+ than the bus address. Not all platforms support this.
+
config PPC_NEED_DMA_SYNC_OPS
def_bool y
- depends on NOT_COHERENT_CACHE
+ depends on (NOT_COHERENT_CACHE || SWIOTLB)
config HOTPLUG_CPU
bool "Support for enabling/disabling CPUs"
