crypto: rockchip - better handle cipher key

The key should not be set in hardware too much in advance, this will
fail it 2 TFM with different keys generate alternative requests.
The key should be stored and used just before doing cipher operations.

Fixes: ce0183cb ("crypto: rockchip - switch to skcipher API")
Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/rockchip/rk3288_crypto.h

@@ -245,6 +245,7 @@ struct rk_ahash_rctx {
 struct rk_cipher_ctx {
 	struct rk_crypto_info		*dev;
 	unsigned int			keylen;
+	u8				key[AES_MAX_KEY_SIZE];
 	u8				iv[AES_BLOCK_SIZE];
 	struct crypto_skcipher *fallback_tfm;
 };

drivers/crypto/rockchip/rk3288_crypto_skcipher.c

@@ -95,7 +95,7 @@ static int rk_aes_setkey(struct crypto_skcipher *cipher,
 	    keylen != AES_KEYSIZE_256)
 		return -EINVAL;
 	ctx->keylen = keylen;
-	memcpy_toio(ctx->dev->reg + RK_CRYPTO_AES_KEY_0, key, keylen);
+	memcpy(ctx->key, key, keylen);
 
 	return crypto_skcipher_setkey(ctx->fallback_tfm, key, keylen);
 }
@@ -111,7 +111,7 @@ static int rk_des_setkey(struct crypto_skcipher *cipher,
 		return err;
 
 	ctx->keylen = keylen;
-	memcpy_toio(ctx->dev->reg + RK_CRYPTO_TDES_KEY1_0, key, keylen);
+	memcpy(ctx->key, key, keylen);
 
 	return crypto_skcipher_setkey(ctx->fallback_tfm, key, keylen);
 }
@@ -127,7 +127,8 @@ static int rk_tdes_setkey(struct crypto_skcipher *cipher,
 		return err;
 
 	ctx->keylen = keylen;
-	memcpy_toio(ctx->dev->reg + RK_CRYPTO_TDES_KEY1_0, key, keylen);
+	memcpy(ctx->key, key, keylen);
+
 	return crypto_skcipher_setkey(ctx->fallback_tfm, key, keylen);
 }
 
@@ -283,6 +284,7 @@ static void rk_ablk_hw_init(struct rk_crypto_info *dev)
 			     RK_CRYPTO_TDES_BYTESWAP_IV;
 		CRYPTO_WRITE(dev, RK_CRYPTO_TDES_CTRL, rctx->mode);
 		memcpy_toio(dev->reg + RK_CRYPTO_TDES_IV_0, req->iv, ivsize);
+		memcpy_toio(ctx->dev->reg + RK_CRYPTO_TDES_KEY1_0, ctx->key, ctx->keylen);
 		conf_reg = RK_CRYPTO_DESSEL;
 	} else {
 		rctx->mode |= RK_CRYPTO_AES_FIFO_MODE |
@@ -295,6 +297,7 @@ static void rk_ablk_hw_init(struct rk_crypto_info *dev)
 			rctx->mode |= RK_CRYPTO_AES_256BIT_key;
 		CRYPTO_WRITE(dev, RK_CRYPTO_AES_CTRL, rctx->mode);
 		memcpy_toio(dev->reg + RK_CRYPTO_AES_IV_0, req->iv, ivsize);
+		memcpy_toio(ctx->dev->reg + RK_CRYPTO_AES_KEY_0, ctx->key, ctx->keylen);
 	}
 	conf_reg |= RK_CRYPTO_BYTESWAP_BTFIFO |
 		    RK_CRYPTO_BYTESWAP_BRFIFO;
@@ -484,6 +487,7 @@ static void rk_ablk_exit_tfm(struct crypto_skcipher *tfm)
 {
 	struct rk_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
 
+	memzero_explicit(ctx->key, ctx->keylen);
 	free_page((unsigned long)ctx->dev->addr_vir);
 	crypto_free_skcipher(ctx->fallback_tfm);
 }