swiotlb: use swiotlb_map_page in swiotlb_map_sg_attrs

No need to duplicate the code - map_sg is equivalent to map_page
for each page in the scatterlist.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 15335f3..15755d7 100644 (file)
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -845,37 +845,27 @@ swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
  * same here.
  */
 int
-swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
+swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl, int nelems,
                     enum dma_data_direction dir, unsigned long attrs)
 {
        struct scatterlist *sg;
        int i;
 
-       BUG_ON(dir == DMA_NONE);
-
        for_each_sg(sgl, sg, nelems, i) {
-               phys_addr_t paddr = sg_phys(sg);
-               dma_addr_t dev_addr = phys_to_dma(hwdev, paddr);
-
-               if (swiotlb_force == SWIOTLB_FORCE ||
-                   !dma_capable(hwdev, dev_addr, sg->length)) {
-                       phys_addr_t map = map_single(hwdev, sg_phys(sg),
-                                                    sg->length, dir, attrs);
-                       if (map == SWIOTLB_MAP_ERROR) {
-                               /* Don't panic here, we expect map_sg users
-                                  to do proper error handling. */
-                               attrs |= DMA_ATTR_SKIP_CPU_SYNC;
-                               swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
-                                                      attrs);
-                               sg_dma_len(sgl) = 0;
-                               return 0;
-                       }
-                       sg->dma_address = __phys_to_dma(hwdev, map);
-               } else
-                       sg->dma_address = dev_addr;
+               sg->dma_address = swiotlb_map_page(dev, sg_page(sg), sg->offset,
+                               sg->length, dir, attrs);
+               if (sg->dma_address == DIRECT_MAPPING_ERROR)
+                       goto out_error;
                sg_dma_len(sg) = sg->length;
        }
+
        return nelems;
+
+out_error:
+       swiotlb_unmap_sg_attrs(dev, sgl, i, dir,
+                       attrs | DMA_ATTR_SKIP_CPU_SYNC);
+       sg_dma_len(sgl) = 0;
+       return 0;
 }
 
 /*