Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  async_xor: dma_map destination DMA_BIDIRECTIONAL
  dmaengine: protect 'id' from concurrent registrations
  ioat: wait for self-test completion

1 files changed, 9 insertions, 2 deletions

diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
index c029d3eb9ef0..595b78672b36 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -53,10 +53,17 @@ do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list,
         int xor_src_cnt;
         dma_addr_t dma_dest;
 
-        dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_FROM_DEVICE);
-        for (i = 0; i < src_cnt; i++)
+        /* map the dest bidrectional in case it is re-used as a source */
+        dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_BIDIRECTIONAL);
+        for (i = 0; i < src_cnt; i++) {
+                /* only map the dest once */
+                if (unlikely(src_list[i] == dest)) {
+                        dma_src[i] = dma_dest;
+                        continue;
+                }
                 dma_src[i] = dma_map_page(dma->dev, src_list[i], offset,
                                           len, DMA_TO_DEVICE);
+        }
 
         while (src_cnt) {
                 async_flags = flags;