[PATCH 22/31] metag: handle page-less SG entries

[Christoph Hellwig <hch@lst.de>]

Make all cache invalidation conditional on sg_has_page().

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/metag/include/asm/dma-mapping.h | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/metag/include/asm/dma-mapping.h b/arch/metag/include/asm/dma-mapping.h
index eb5cdec..2ae9057 100644
--- a/arch/metag/include/asm/dma-mapping.h
+++ b/arch/metag/include/asm/dma-mapping.h
@@ -55,10 +55,9 @@ dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
 	WARN_ON(nents == 0 || sglist[0].length == 0);
 
 	for_each_sg(sglist, sg, nents, i) {
-		BUG_ON(!sg_page(sg));
-
 		sg->dma_address = sg_phys(sg);
-		dma_sync_for_device(sg_virt(sg), sg->length, direction);
+		if (sg_has_page(sg))
+			dma_sync_for_device(sg_virt(sg), sg->length, direction);
 	}
 
 	return nents;
@@ -94,10 +93,9 @@ dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nhwentries,
 	WARN_ON(nhwentries == 0 || sglist[0].length == 0);
 
 	for_each_sg(sglist, sg, nhwentries, i) {
-		BUG_ON(!sg_page(sg));
-
 		sg->dma_address = sg_phys(sg);
-		dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
+		if (sg_has_page(sg))
+			dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
 	}
 }
 
@@ -140,8 +138,10 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist, int nelems,
 	int i;
 	struct scatterlist *sg;
 
-	for_each_sg(sglist, sg, nelems, i)
-		dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
+	for_each_sg(sglist, sg, nelems, i) {
+		if (sg_has_page(sg))
+			dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
+	}
 }
 
 static inline void
@@ -151,8 +151,10 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist,
 	int i;
 	struct scatterlist *sg;
 
-	for_each_sg(sglist, sg, nelems, i)
-		dma_sync_for_device(sg_virt(sg), sg->length, direction);
+	for_each_sg(sglist, sg, nelems, i) {
+		if (sg_has_page(sg))
+			dma_sync_for_device(sg_virt(sg), sg->length, direction);
+	}
 }
 
 static inline int
-- 
1.9.1