swiotlb: sg chaining support

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

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 30c1400e749e8299be6767e32e9f3531ae18a0a4..c419ecf334c30a063374b0cced7cbad8afeed7bc 100644 (file)
--- 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