[PATCH 19/31] arc: handle page-less SG entries

[Christoph Hellwig]

Make all cache invalidation conditional on sg_has_page() and use
sg_phys to get the physical address directly.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 arch/arc/include/asm/dma-mapping.h | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/arch/arc/include/asm/dma-mapping.h b/arch/arc/include/asm/dma-mapping.h
index 2d28ba9..42eb526 100644
--- a/arch/arc/include/asm/dma-mapping.h
+++ b/arch/arc/include/asm/dma-mapping.h
@@ -108,9 +108,13 @@ dma_map_sg(struct device *dev, struct scatterlist *sg,
 	struct scatterlist *s;
 	int i;
 
-	for_each_sg(sg, s, nents, i)
-		s->dma_address = dma_map_page(dev, sg_page(s), s->offset,
-					       s->length, dir);
+	for_each_sg(sg, s, nents, i) {
+		if (sg_has_page(s)) {
+			_dma_cache_sync((unsigned long)sg_virt(s), s->length,
+					dir);
+		}
+		s->dma_address = sg_phys(s);
+	}
 
 	return nents;
 }
@@ -163,8 +167,12 @@ 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_cache_sync((unsigned int)sg_virt(sg), sg->length, dir);
+	for_each_sg(sglist, sg, nelems, i) {
+		if (sg_has_page(sg)) {
+			_dma_cache_sync((unsigned int)sg_virt(sg), sg->length,
+					dir);
+		}
+	}
 }
 
 static inline void
@@ -174,8 +182,12 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist,
 	int i;
 	struct scatterlist *sg;
 
-	for_each_sg(sglist, sg, nelems, i)
-		_dma_cache_sync((unsigned int)sg_virt(sg), sg->length, dir);
+	for_each_sg(sglist, sg, nelems, i) {
+		if (sg_has_page(sg)) {
+			_dma_cache_sync((unsigned int)sg_virt(sg), sg->length,
+				dir);
+		}
+	}
 }
 
 static inline int dma_supported(struct device *dev, u64 dma_mask)
-- 
1.9.1