swiotlb: sg chaining support

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 12 insertions, 7 deletions

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 30c1400e749e..c419ecf334c3 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -677,16 +677,17 @@ swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr,
  * same here.
  */
 int
-swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
+swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
                int dir)
 {
+        struct scatterlist *sg;
         void *addr;
         dma_addr_t dev_addr;
         int i;
 
         BUG_ON(dir == DMA_NONE);
 
-        for (i = 0; i < nelems; i++, sg++) {
+        for_each_sg(sgl, sg, nelems, i) {
                 addr = SG_ENT_VIRT_ADDRESS(sg);
                 dev_addr = virt_to_bus(addr);
                 if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
@@ -696,7 +697,7 @@ swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
                                    to do proper error handling. */
                                 swiotlb_full(hwdev, sg->length, dir, 0);
                                 swiotlb_unmap_sg(hwdev, sg - i, i, dir);
-                                sg[0].dma_length = 0;
+                                sgl[0].dma_length = 0;
                                 return 0;
                         }
                         sg->dma_address = virt_to_bus(map);
@@ -712,19 +713,21 @@ swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
  * concerning calls here are the same as for swiotlb_unmap_single() above.
  */
 void
-swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
+swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
                  int dir)
 {
+        struct scatterlist *sg;
         int i;
 
         BUG_ON(dir == DMA_NONE);
 
-        for (i = 0; i < nelems; i++, sg++)
+        for_each_sg(sgl, sg, nelems, i) {
                 if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
                         unmap_single(hwdev, bus_to_virt(sg->dma_address),
                                      sg->dma_length, dir);
                 else if (dir == DMA_FROM_DEVICE)
                         dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
+        }
 }
 
 /*
@@ -735,19 +738,21 @@ swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
  * and usage.
  */
 static void
-swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sg,
+swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
                 int nelems, int dir, int target)
 {
+        struct scatterlist *sg;
         int i;
 
         BUG_ON(dir == DMA_NONE);
 
-        for (i = 0; i < nelems; i++, sg++)
+        for_each_sg(sgl, sg, nelems, i) {
                 if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
                         sync_single(hwdev, bus_to_virt(sg->dma_address),
                                     sg->dma_length, dir, target);
                 else if (dir == DMA_FROM_DEVICE)
                         dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
+        }
 }
 
 void