crypto: hash - Pull out the functions to save/restore request

The functions to save original request within a newly adjusted request
and it's counterpart to restore the original request can be re-used by
more code in the crypto/ahash.c file. Pull these functions out from the
code so they're available.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/ahash.c

@@ -190,55 +190,12 @@ static inline unsigned int ahash_align_buffer_size(unsigned len,
 	return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
 }
 
-static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
-{
-	struct ahash_request_priv *priv = req->priv;
-
-	if (err == -EINPROGRESS)
-		return;
-
-	if (!err)
-		memcpy(priv->result, req->result,
-		       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
-
-	/* Restore the original crypto request. */
-	req->result = priv->result;
-	req->base.complete = priv->complete;
-	req->base.data = priv->data;
-	req->priv = NULL;
-
-	/* Free the req->priv.priv from the ADJUSTED request. */
-	kzfree(priv);
-}
-
-static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
-{
-	struct ahash_request *areq = req->data;
-
-	/*
-	 * Restore the original request, see ahash_op_unaligned() for what
-	 * goes where.
-	 *
-	 * The "struct ahash_request *req" here is in fact the "req.base"
-	 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
-	 * is a pointer to self, it is also the ADJUSTED "req" .
-	 */
-
-	/* First copy areq->result into areq->priv.result */
-	ahash_op_unaligned_finish(areq, err);
-
-	/* Complete the ORIGINAL request. */
-	areq->base.complete(&areq->base, err);
-}
-
-static int ahash_op_unaligned(struct ahash_request *req,
-			      int (*op)(struct ahash_request *))
+static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	unsigned long alignmask = crypto_ahash_alignmask(tfm);
 	unsigned int ds = crypto_ahash_digestsize(tfm);
 	struct ahash_request_priv *priv;
-	int err;
 
 	priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
 		       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
@@ -281,10 +238,70 @@ static int ahash_op_unaligned(struct ahash_request *req,
 	 */
 
 	req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
-	req->base.complete = ahash_op_unaligned_done;
+	req->base.complete = cplt;
 	req->base.data = req;
 	req->priv = priv;
 
+	return 0;
+}
+
+static void ahash_restore_req(struct ahash_request *req)
+{
+	struct ahash_request_priv *priv = req->priv;
+
+	/* Restore the original crypto request. */
+	req->result = priv->result;
+	req->base.complete = priv->complete;
+	req->base.data = priv->data;
+	req->priv = NULL;
+
+	/* Free the req->priv.priv from the ADJUSTED request. */
+	kzfree(priv);
+}
+
+static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
+{
+	struct ahash_request_priv *priv = req->priv;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	if (!err)
+		memcpy(priv->result, req->result,
+		       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
+
+	ahash_restore_req(req);
+}
+
+static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
+{
+	struct ahash_request *areq = req->data;
+
+	/*
+	 * Restore the original request, see ahash_op_unaligned() for what
+	 * goes where.
+	 *
+	 * The "struct ahash_request *req" here is in fact the "req.base"
+	 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
+	 * is a pointer to self, it is also the ADJUSTED "req" .
+	 */
+
+	/* First copy req->result into req->priv.result */
+	ahash_op_unaligned_finish(areq, err);
+
+	/* Complete the ORIGINAL request. */
+	areq->base.complete(&areq->base, err);
+}
+
+static int ahash_op_unaligned(struct ahash_request *req,
+			      int (*op)(struct ahash_request *))
+{
+	int err;
+
+	err = ahash_save_req(req, ahash_op_unaligned_done);
+	if (err)
+		return err;
+
 	err = op(req);
 	ahash_op_unaligned_finish(req, err);