[PATCH 07/16] crypto: rockchip: add fallback for ahash

[Corentin Labbe <clabbe@baylibre.com>]

Adds a fallback for all case hardware cannot handle.

Fixes: ce0183cb6464b ("crypto: rockchip - switch to skcipher API")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
---
 drivers/crypto/rockchip/rk3288_crypto_ahash.c | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/crypto/rockchip/rk3288_crypto_ahash.c b/drivers/crypto/rockchip/rk3288_crypto_ahash.c
index 49017d1fb510..417cf4487514 100644
--- a/drivers/crypto/rockchip/rk3288_crypto_ahash.c
+++ b/drivers/crypto/rockchip/rk3288_crypto_ahash.c
@@ -16,6 +16,40 @@
  * so we put the fixed hash out when met zero message.
  */
 
+static bool rk_ahash_need_fallback(struct ahash_request *req)
+{
+	struct scatterlist *sg;
+
+	sg = req->src;
+	while (sg) {
+		if (!IS_ALIGNED(sg->offset, sizeof(u32))) {
+			return true;
+		}
+		if (sg->length % 4) {
+			return true;
+		}
+		sg = sg_next(sg);
+	}
+	return false;
+}
+
+static int rk_ahash_digest_fb(struct ahash_request *areq)
+{
+	struct rk_ahash_rctx *rctx = ahash_request_ctx(areq);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
+	struct rk_ahash_ctx *tfmctx = crypto_ahash_ctx(tfm);
+
+	ahash_request_set_tfm(&rctx->fallback_req, tfmctx->fallback_tfm);
+	rctx->fallback_req.base.flags = areq->base.flags &
+					CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	rctx->fallback_req.nbytes = areq->nbytes;
+	rctx->fallback_req.src = areq->src;
+	rctx->fallback_req.result = areq->result;
+
+	return crypto_ahash_digest(&rctx->fallback_req);
+}
+
 static int zero_message_process(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
@@ -167,6 +201,9 @@ static int rk_ahash_digest(struct ahash_request *req)
 	struct rk_ahash_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
 	struct rk_crypto_info *dev = tctx->dev;
 
+	if (rk_ahash_need_fallback(req))
+		return rk_ahash_digest_fb(req);
+
 	if (!req->nbytes)
 		return zero_message_process(req);
 	else
-- 
2.34.1