1 files changed, 30 insertions, 23 deletions

diff --git a/arch/sparc64/kernel/iommu.c b/arch/sparc64/kernel/iommu.c
index b35a62167e9..070a4846c0c 100644
--- a/arch/sparc64/kernel/iommu.c
+++ b/arch/sparc64/kernel/iommu.c
@@ -472,15 +472,13 @@ static void dma_4u_unmap_single(struct device *dev, dma_addr_t bus_addr,
 	spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
-#define SG_ENT_PHYS_ADDRESS(SG)	\
-	(__pa(page_address((SG)->page)) + (SG)->offset)
+#define SG_ENT_PHYS_ADDRESS(SG)	(__pa(sg_virt((SG))))
 
-static inline void fill_sg(iopte_t *iopte, struct scatterlist *sg,
-			   int nused, int nelems,
-			   unsigned long iopte_protection)
+static void fill_sg(iopte_t *iopte, struct scatterlist *sg,
+		    int nused, int nelems,
+		    unsigned long iopte_protection)
 {
 	struct scatterlist *dma_sg = sg;
-	struct scatterlist *sg_end = sg + nelems;
 	int i;
 
 	for (i = 0; i < nused; i++) {
@@ -515,7 +513,8 @@ static inline void fill_sg(iopte_t *iopte, struct scatterlist *sg,
 					len -= (IO_PAGE_SIZE - (tmp & (IO_PAGE_SIZE - 1UL)));
 					break;
 				}
-				sg++;
+				sg = sg_next(sg);
+				nelems--;
 			}
 
 			pteval = iopte_protection | (pteval & IOPTE_PAGE);
@@ -528,24 +527,26 @@ static inline void fill_sg(iopte_t *iopte, struct scatterlist *sg,
 			}
 
 			pteval = (pteval & IOPTE_PAGE) + len;
-			sg++;
+			sg = sg_next(sg);
+			nelems--;
 
 			/* Skip over any tail mappings we've fully mapped,
 			 * adjusting pteval along the way.  Stop when we
 			 * detect a page crossing event.
 			 */
-			while (sg < sg_end &&
+			while (nelems &&
 			       (pteval << (64 - IO_PAGE_SHIFT)) != 0UL &&
 			       (pteval == SG_ENT_PHYS_ADDRESS(sg)) &&
 			       ((pteval ^
 				 (SG_ENT_PHYS_ADDRESS(sg) + sg->length - 1UL)) >> IO_PAGE_SHIFT) == 0UL) {
 				pteval += sg->length;
-				sg++;
+				sg = sg_next(sg);
+				nelems--;
 			}
 			if ((pteval << (64 - IO_PAGE_SHIFT)) == 0UL)
 				pteval = ~0UL;
 		} while (dma_npages != 0);
-		dma_sg++;
+		dma_sg = sg_next(dma_sg);
 	}
 }
 
@@ -563,9 +564,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
 	/* Fast path single entry scatterlists. */
 	if (nelems == 1) {
 		sglist->dma_address =
-			dma_4u_map_single(dev,
-					  (page_address(sglist->page) +
-					   sglist->offset),
+			dma_4u_map_single(dev, sg_virt(sglist),
 					  sglist->length, direction);
 		if (unlikely(sglist->dma_address == DMA_ERROR_CODE))
 			return 0;
@@ -606,7 +605,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
 	sgtmp = sglist;
 	while (used && sgtmp->dma_length) {
 		sgtmp->dma_address += dma_base;
-		sgtmp++;
+		sgtmp = sg_next(sgtmp);
 		used--;
 	}
 	used = nelems - used;
@@ -642,6 +641,7 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 	struct strbuf *strbuf;
 	iopte_t *base;
 	unsigned long flags, ctx, i, npages;
+	struct scatterlist *sg, *sgprv;
 	u32 bus_addr;
 
 	if (unlikely(direction == DMA_NONE)) {
@@ -654,11 +654,14 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 
 	bus_addr = sglist->dma_address & IO_PAGE_MASK;
 
-	for (i = 1; i < nelems; i++)
-		if (sglist[i].dma_length == 0)
+	sgprv = NULL;
+	for_each_sg(sglist, sg, nelems, i) {
+		if (sg->dma_length == 0)
 			break;
-	i--;
-	npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) -
+		sgprv = sg;
+	}
+
+	npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length) -
 		  bus_addr) >> IO_PAGE_SHIFT;
 
 	base = iommu->page_table +
@@ -730,6 +733,7 @@ static void dma_4u_sync_sg_for_cpu(struct device *dev,
 	struct iommu *iommu;
 	struct strbuf *strbuf;
 	unsigned long flags, ctx, npages, i;
+	struct scatterlist *sg, *sgprv;
 	u32 bus_addr;
 
 	iommu = dev->archdata.iommu;
@@ -753,11 +757,14 @@ static void dma_4u_sync_sg_for_cpu(struct device *dev,
 
 	/* Step 2: Kick data out of streaming buffers. */
 	bus_addr = sglist[0].dma_address & IO_PAGE_MASK;
-	for(i = 1; i < nelems; i++)
-		if (!sglist[i].dma_length)
+	sgprv = NULL;
+	for_each_sg(sglist, sg, nelems, i) {
+		if (sg->dma_length == 0)
 			break;
-	i--;
-	npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length)
+		sgprv = sg;
+	}
+
+	npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length)
 		  - bus_addr) >> IO_PAGE_SHIFT;
 	strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);