The unmap methods need to transfer memory ownership back from the device
to the cpu by identical means as dma_sync_*_to_cpu. I'm not sure powerpc
needs to do any work in this transfer direction, but given that it does
invalidate the caches in dma_sync_*_to_cpu already we should make sure
we also do so on unmapping.
Signed-off-by: Christoph Hellwig <h...@lst.de>
---
arch/powerpc/kernel/dma.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index dbfc7056d7df..d442d23e182b 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -210,10 +210,15 @@ static int dma_nommu_map_sg(struct device *dev, struct
scatterlist *sgl,
return nents;
}
-static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sg,
+static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
+ struct scatterlist *sg;
+ int i;
+
+ for_each_sg(sgl, sg, nents, i)
+ __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
static u64 dma_nommu_get_required_mask(struct device *dev)
@@ -247,6 +252,8 @@ static inline void dma_nommu_unmap_page(struct device *dev,
enum dma_data_direction direction,
unsigned long attrs)
{
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ __dma_sync(bus_to_virt(dma_address), size, dir);
}
#ifdef CONFIG_NOT_COHERENT_CACHE
--
2.19.2
