Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block

[cascardo/linux.git] / lib / swiotlb.c

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 3412688..76f29ec 100644 (file)
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -537,8 +537,9 @@ EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single);
  * Allocates bounce buffer and returns its kernel virtual address.
  */
 
-phys_addr_t map_single(struct device *hwdev, phys_addr_t phys, size_t size,
-                      enum dma_data_direction dir)
+static phys_addr_t
+map_single(struct device *hwdev, phys_addr_t phys, size_t size,
+          enum dma_data_direction dir)
 {
        dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start);
 
@@ -655,7 +656,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                 */
                phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
                if (paddr == SWIOTLB_MAP_ERROR)
-                       return NULL;
+                       goto err_warn;
 
                ret = phys_to_virt(paddr);
                dev_addr = phys_to_dma(hwdev, paddr);
@@ -669,7 +670,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                        /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
                        swiotlb_tbl_unmap_single(hwdev, paddr,
                                                 size, DMA_TO_DEVICE);
-                       return NULL;
+                       goto err_warn;
                }
        }
 
@@ -677,6 +678,13 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
        memset(ret, 0, size);
 
        return ret;
+
+err_warn:
+       pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n",
+               dev_name(hwdev), size);
+       dump_stack();
+
+       return NULL;
 }
 EXPORT_SYMBOL(swiotlb_alloc_coherent);