[PATCH] powerpc: Fix swiotlb ops for ppc64

[Kumar Gala]

We assumed before that alloc_coherent & free_coherent ops would always
be direct because of 32-bit systems and how we utilize highmem & lowmem.
However, on 64-bit systems we typically treat all memory as lowmem so
the same assumptions are not valid.  We need to utilze the swiotlb
versions of alloc_coherent & free_coherent on 64-bit systems.

Signed-off-by: Kumar Gala <galak at kernel.crashing.org>
---
 arch/powerpc/kernel/dma-swiotlb.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
index 1ebc918..5000fd4 100644
--- a/arch/powerpc/kernel/dma-swiotlb.c
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -40,15 +40,20 @@ static u64 swiotlb_powerpc_get_required(struct device *dev)
 }
 
 /*
- * At the moment, all platforms that use this code only require
- * swiotlb to be used if we're operating on HIGHMEM.  Since
+ * We assume that 32-bit systems will utilize HIGHMEM and that we're
+ * able to DMA directly to anything in the LOWMEM region. Since
  * we don't ever call anything other than map_sg, unmap_sg,
  * map_page, and unmap_page on highmem, use normal dma_ops
  * for everything else.
  */
 struct dma_map_ops swiotlb_dma_ops = {
+#ifdef CONFIG_PPC64
+	.alloc_coherent = swiotlb_alloc_coherent,
+	.free_coherent = swiotlb_free_coherent,
+#else
 	.alloc_coherent = dma_direct_alloc_coherent,
 	.free_coherent = dma_direct_free_coherent,
+#endif
 	.map_sg = swiotlb_map_sg_attrs,
 	.unmap_sg = swiotlb_unmap_sg_attrs,
 	.dma_supported = swiotlb_dma_supported,
-- 
1.7.3.4