powerpc: Add sync_*_for_* to dma_ops

We need to swap these out once we start using swiotlb, so add
them to dma_ops.  Create CONFIG_PPC_NEED_DMA_SYNC_OPS Kconfig
option; this is currently enabled automatically if we're
CONFIG_NOT_COHERENT_CACHE.  In the future, this will also
be enabled for builds that need swiotlb.  If PPC_NEED_DMA_SYNC_OPS
is not defined, the dma_sync_*_for_* ops compile to nothing.
Otherwise, they access the dma_ops pointers for the sync ops.

This patch also changes dma_sync_single_range_* to actually
sync the range - previously it was using a generous
dma_sync_single.  dma_sync_single_* is now implemented
as a dma_sync_single_range with an offset of 0.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 3a6eaa876ee1..1c5c8a6fc129 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -120,6 +120,26 @@ static inline void dma_direct_unmap_page(struct device *dev,
 {
 }
 
+#ifdef CONFIG_NOT_COHERENT_CACHE
+static inline void dma_direct_sync_sg(struct device *dev,
+                struct scatterlist *sgl, int nents,
+                enum dma_data_direction direction)
+{
+        struct scatterlist *sg;
+        int i;
+
+        for_each_sg(sgl, sg, nents, i)
+                __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
+}
+
+static inline void dma_direct_sync_single_range(struct device *dev,
+                dma_addr_t dma_handle, unsigned long offset, size_t size,
+                enum dma_data_direction direction)
+{
+        __dma_sync(bus_to_virt(dma_handle+offset), size, direction);
+}
+#endif
+
 struct dma_mapping_ops dma_direct_ops = {
         .alloc_coherent = dma_direct_alloc_coherent,
         .free_coherent  = dma_direct_free_coherent,
@@ -128,5 +148,11 @@ struct dma_mapping_ops dma_direct_ops = {
         .dma_supported  = dma_direct_dma_supported,
         .map_page       = dma_direct_map_page,
         .unmap_page     = dma_direct_unmap_page,
+#ifdef CONFIG_NOT_COHERENT_CACHE
+        .sync_single_range_for_cpu      = dma_direct_sync_single_range,
+        .sync_single_range_for_device   = dma_direct_sync_single_range,
+        .sync_sg_for_cpu                = dma_direct_sync_sg,
+        .sync_sg_for_device             = dma_direct_sync_sg,
+#endif
 };
 EXPORT_SYMBOL(dma_direct_ops);