crypto: tegra - Use HMAC fallback when keyslots are full

[ Upstream commit f80a2e2 ]

The intermediate results for HMAC is stored in the allocated keyslot by
the hardware. Dynamic allocation of keyslot during an operation is hence
not possible. As the number of keyslots are limited in the hardware,
fallback to the HMAC software implementation if keyslots are not available

Fixes: 0880bb3 ("crypto: tegra - Add Tegra Security Engine driver")
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Akhil R

drivers/crypto/tegra/tegra-se-hash.c

@@ -567,13 +567,18 @@ static int tegra_hmac_setkey(struct crypto_ahash *tfm, const u8 *key,
 			     unsigned int keylen)
 {
 	struct tegra_sha_ctx *ctx = crypto_ahash_ctx(tfm);
+	int ret;
 
 	if (aes_check_keylen(keylen))
 		return tegra_hmac_fallback_setkey(ctx, key, keylen);
 
+	ret = tegra_key_submit(ctx->se, key, keylen, ctx->alg, &ctx->key_id);
+	if (ret)
+		return tegra_hmac_fallback_setkey(ctx, key, keylen);
+
 	ctx->fallback = false;
 
-	return tegra_key_submit(ctx->se, key, keylen, ctx->alg, &ctx->key_id);
+	return 0;
 }
 
 static int tegra_sha_update(struct ahash_request *req)