crypto: sun8i-ss - do not allocate memory when handling hash requests

Instead of allocate memory on each requests, it is easier to
pre-allocate buffers.
This made error path easier.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c

@@ -486,6 +486,16 @@ static int allocate_flows(struct sun8i_ss_dev *ss)
 				goto error_engine;
 		}
 
+		/* the padding could be up to two block. */
+		ss->flows[i].pad = devm_kmalloc(ss->dev, SHA256_BLOCK_SIZE * 2,
+						GFP_KERNEL | GFP_DMA);
+		if (!ss->flows[i].pad)
+			goto error_engine;
+		ss->flows[i].result = devm_kmalloc(ss->dev, SHA256_DIGEST_SIZE,
+						   GFP_KERNEL | GFP_DMA);
+		if (!ss->flows[i].result)
+			goto error_engine;
+
 		ss->flows[i].engine = crypto_engine_alloc_init(ss->dev, true);
 		if (!ss->flows[i].engine) {
 			dev_err(ss->dev, "Cannot allocate engine\n");

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c

@@ -332,18 +332,11 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
 	if (digestsize == SHA224_DIGEST_SIZE)
 		digestsize = SHA256_DIGEST_SIZE;
 
-	/* the padding could be up to two block. */
-	pad = kzalloc(algt->alg.hash.halg.base.cra_blocksize * 2, GFP_KERNEL | GFP_DMA);
-	if (!pad)
-		return -ENOMEM;
+	result = ss->flows[rctx->flow].result;
+	pad = ss->flows[rctx->flow].pad;
+	memset(pad, 0, algt->alg.hash.halg.base.cra_blocksize * 2);
 	bf = (__le32 *)pad;
 
-	result = kzalloc(digestsize, GFP_KERNEL | GFP_DMA);
-	if (!result) {
-		kfree(pad);
-		return -ENOMEM;
-	}
-
 	for (i = 0; i < MAX_SG; i++) {
 		rctx->t_dst[i].addr = 0;
 		rctx->t_dst[i].len = 0;
@@ -439,8 +432,6 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
 
 	memcpy(areq->result, result, algt->alg.hash.halg.digestsize);
 theend:
-	kfree(pad);
-	kfree(result);
 	local_bh_disable();
 	crypto_finalize_hash_request(engine, breq, err);
 	local_bh_enable();

drivers/crypto/allwinner/sun8i-ss/sun8i-ss.h

@@ -123,6 +123,8 @@ struct sginfo {
  * @stat_req:	number of request done by this flow
  * @iv:		list of IV to use for each step
  * @biv:	buffer which contain the backuped IV
+ * @pad:	padding buffer for hash operations
+ * @result:	buffer for storing the result of hash operations
  */
 struct sun8i_ss_flow {
 	struct crypto_engine *engine;
@@ -130,6 +132,8 @@ struct sun8i_ss_flow {
 	int status;
 	u8 *iv[MAX_SG];
 	u8 *biv;
+	void *pad;
+	void *result;
 #ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG
 	unsigned long stat_req;
 #endif