3 files changed, 34 insertions, 8 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;
diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c
index c7a9306d951d..6be317262200 100644
--- a/drivers/dma/iop-adma.c
+++ b/drivers/dma/iop-adma.c
@@ -85,18 +85,28 @@ iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc,
                         enum dma_ctrl_flags flags = desc->async_tx.flags;
                         u32 src_cnt;
                         dma_addr_t addr;
+                        dma_addr_t dest;
 
+                        src_cnt = unmap->unmap_src_cnt;
+                        dest = iop_desc_get_dest_addr(unmap, iop_chan);
                         if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
-                                addr = iop_desc_get_dest_addr(unmap, iop_chan);
-                                dma_unmap_page(dev, addr, len, DMA_FROM_DEVICE);
+                                enum dma_data_direction dir;
+
+                                if (src_cnt > 1) /* is xor? */
+                                        dir = DMA_BIDIRECTIONAL;
+                                else
+                                        dir = DMA_FROM_DEVICE;
+
+                                dma_unmap_page(dev, dest, len, dir);
                         }
 
                         if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
-                                src_cnt = unmap->unmap_src_cnt;
                                 while (src_cnt--) {
                                         addr = iop_desc_get_src_addr(unmap,
                                                                      iop_chan,
                                                                      src_cnt);
+                                        if (addr == dest)
+                                                continue;
                                         dma_unmap_page(dev, addr, len,
                                                        DMA_TO_DEVICE);
                                 }
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index 0328da020a10..bcda17426411 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -311,17 +311,26 @@ mv_xor_run_tx_complete_actions(struct mv_xor_desc_slot *desc,
                         enum dma_ctrl_flags flags = desc->async_tx.flags;
                         u32 src_cnt;
                         dma_addr_t addr;
+                        dma_addr_t dest;
 
+                        src_cnt = unmap->unmap_src_cnt;
+                        dest = mv_desc_get_dest_addr(unmap);
                         if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
-                                addr = mv_desc_get_dest_addr(unmap);
-                                dma_unmap_page(dev, addr, len, DMA_FROM_DEVICE);
+                                enum dma_data_direction dir;
+
+                                if (src_cnt > 1) /* is xor ? */
+                                        dir = DMA_BIDIRECTIONAL;
+                                else
+                                        dir = DMA_FROM_DEVICE;
+                                dma_unmap_page(dev, dest, len, dir);
                         }
 
                         if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
-                                src_cnt = unmap->unmap_src_cnt;
                                 while (src_cnt--) {
                                         addr = mv_desc_get_src_addr(unmap,
                                                                     src_cnt);
+                                        if (addr == dest)
+                                                continue;
                                         dma_unmap_page(dev, addr, len,
                                                        DMA_TO_DEVICE);
                                 }