async_tx: kill ASYNC_TX_ASSUME_COHERENT

Remove the unused ASYNC_TX_ASSUME_COHERENT flag.  Async_tx is
meant to hide the difference between asynchronous hardware and synchronous
software operations, this flag requires clients to understand cache
coherency consequences of the async path.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/crypto/async_tx/async_memset.c b/crypto/async_tx/async_memset.c
index 66ef635..7609728 100644
--- a/crypto/async_tx/async_memset.c
+++ b/crypto/async_tx/async_memset.c
@@ -35,7 +35,7 @@
  * @val: fill value
  * @offset: offset in pages to start transaction
  * @len: length in bytes
- * @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
+ * @flags: ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
  * @depend_tx: memset depends on the result of this transaction
  * @cb_fn: function to call when the memcpy completes
  * @cb_param: parameter to pass to the callback routine
@@ -55,13 +55,11 @@
 
 	if (tx) { /* run the memset asynchronously */
 		dma_addr_t dma_addr;
-		enum dma_data_direction dir;
 
 		pr_debug("%s: (async) len: %zu\n", __FUNCTION__, len);
-		dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
-			DMA_NONE : DMA_FROM_DEVICE;
 
-		dma_addr = dma_map_page(device->dev, dest, offset, len, dir);
+		dma_addr = dma_map_page(device->dev, dest, offset, len,
+					DMA_FROM_DEVICE);
 		tx->tx_set_dest(dma_addr, tx, 0);
 
 		async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);