crypto: mv_cesa - Make the copy-back of data optional

Make the copy-back of data optional (not done in hashing requests)
Signed-off-by: Uri Simchoni <uri@jdland.co.il>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/mv_cesa.c

@@ -40,6 +40,7 @@ enum engine_status {
  * @src_start:		offset to add to src start position (scatter list)
  * @crypt_len:		length of current crypt process
  * @hw_nbytes:		total bytes to process in hw for this request
+ * @copy_back:		whether to copy data back (crypt) or not (hash)
  * @sg_dst_left:	bytes left dst to process in this scatter list
  * @dst_start:		offset to add to dst start position (scatter list)
  * @hw_processed_bytes:	number of bytes processed by hw (request).
@@ -60,6 +61,7 @@ struct req_progress {
 	int crypt_len;
 	int hw_nbytes;
 	/* dst mostly */
+	int copy_back;
 	int sg_dst_left;
 	int dst_start;
 	int hw_processed_bytes;
@@ -267,10 +269,10 @@ static void dequeue_complete_req(void)
 	struct crypto_async_request *req = cpg->cur_req;
 	void *buf;
 	int ret;
+	cpg->p.hw_processed_bytes += cpg->p.crypt_len;
+	if (cpg->p.copy_back) {
 		int need_copy_len = cpg->p.crypt_len;
 		int sram_offset = 0;
-
-	cpg->p.hw_processed_bytes += cpg->p.crypt_len;
 		do {
 			int dst_copy;
 
@@ -294,6 +296,8 @@ static void dequeue_complete_req(void)
 			need_copy_len -= dst_copy;
 			cpg->p.dst_start += dst_copy;
 		} while (need_copy_len > 0);
+	}
+
 
 	BUG_ON(cpg->eng_st != ENGINE_W_DEQUEUE);
 	if (cpg->p.hw_processed_bytes < cpg->p.hw_nbytes) {
@@ -336,6 +340,7 @@ static void mv_enqueue_new_req(struct ablkcipher_request *req)
 	p->hw_nbytes = req->nbytes;
 	p->complete = mv_crypto_algo_completion;
 	p->process = mv_process_current_q;
+	p->copy_back = 1;
 
 	num_sgs = count_sgs(req->src, req->nbytes);
 	sg_miter_start(&p->src_sg_it, req->src, num_sgs, SG_MITER_FROM_SG);