crypto: rockchip - add fallback for cipher

The hardware does not handle 0 size length request, let's add a
fallback.
Furthermore fallback will be used for all unaligned case the hardware
cannot handle.

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/Kconfig

@@ -669,6 +669,10 @@ config CRYPTO_DEV_IMGTEC_HASH
 config CRYPTO_DEV_ROCKCHIP
 	tristate "Rockchip's Cryptographic Engine driver"
 	depends on OF && ARCH_ROCKCHIP
+	depends on PM
+	select CRYPTO_ECB
+	select CRYPTO_CBC
+	select CRYPTO_DES
 	select CRYPTO_AES
 	select CRYPTO_LIB_DES
 	select CRYPTO_MD5

drivers/crypto/rockchip/rk3288_crypto.h

@@ -246,10 +246,12 @@ struct rk_cipher_ctx {
 	struct rk_crypto_info		*dev;
 	unsigned int			keylen;
 	u8				iv[AES_BLOCK_SIZE];
+	struct crypto_skcipher *fallback_tfm;
 };
 
 struct rk_cipher_rctx {
 	u32				mode;
+	struct skcipher_request fallback_req;   // keep at the end
 };
 
 enum alg_type {

drivers/crypto/rockchip/rk3288_crypto_skcipher.c

@@ -13,6 +13,63 @@
 
 #define RK_CRYPTO_DEC			BIT(0)
 
+static int rk_cipher_need_fallback(struct skcipher_request *req)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	unsigned int bs = crypto_skcipher_blocksize(tfm);
+	struct scatterlist *sgs, *sgd;
+	unsigned int stodo, dtodo, len;
+
+	if (!req->cryptlen)
+		return true;
+
+	len = req->cryptlen;
+	sgs = req->src;
+	sgd = req->dst;
+	while (sgs && sgd) {
+		if (!IS_ALIGNED(sgs->offset, sizeof(u32))) {
+			return true;
+		}
+		if (!IS_ALIGNED(sgd->offset, sizeof(u32))) {
+			return true;
+		}
+		stodo = min(len, sgs->length);
+		if (stodo % bs) {
+			return true;
+		}
+		dtodo = min(len, sgd->length);
+		if (dtodo % bs) {
+			return true;
+		}
+		if (stodo != dtodo) {
+			return true;
+		}
+		len -= stodo;
+		sgs = sg_next(sgs);
+		sgd = sg_next(sgd);
+	}
+	return false;
+}
+
+static int rk_cipher_fallback(struct skcipher_request *areq)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
+	struct rk_cipher_ctx *op = crypto_skcipher_ctx(tfm);
+	struct rk_cipher_rctx *rctx = skcipher_request_ctx(areq);
+	int err;
+
+	skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm);
+	skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags,
+				      areq->base.complete, areq->base.data);
+	skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst,
+				   areq->cryptlen, areq->iv);
+	if (rctx->mode & RK_CRYPTO_DEC)
+		err = crypto_skcipher_decrypt(&rctx->fallback_req);
+	else
+		err = crypto_skcipher_encrypt(&rctx->fallback_req);
+	return err;
+}
+
 static void rk_crypto_complete(struct crypto_async_request *base, int err)
 {
 	if (base->complete)
@@ -22,10 +79,10 @@ static void rk_crypto_complete(struct crypto_async_request *base, int err)
 static int rk_handle_req(struct rk_crypto_info *dev,
 			 struct skcipher_request *req)
 {
-	if (!IS_ALIGNED(req->cryptlen, dev->align_size))
-		return -EINVAL;
-	else
-		return dev->enqueue(dev, &req->base);
+	if (rk_cipher_need_fallback(req))
+		return rk_cipher_fallback(req);
+
+	return dev->enqueue(dev, &req->base);
 }
 
 static int rk_aes_setkey(struct crypto_skcipher *cipher,
@@ -39,7 +96,8 @@ static int rk_aes_setkey(struct crypto_skcipher *cipher,
 		return -EINVAL;
 	ctx->keylen = keylen;
 	memcpy_toio(ctx->dev->reg + RK_CRYPTO_AES_KEY_0, key, keylen);
-	return 0;
+
+	return crypto_skcipher_setkey(ctx->fallback_tfm, key, keylen);
 }
 
 static int rk_des_setkey(struct crypto_skcipher *cipher,
@@ -54,7 +112,8 @@ static int rk_des_setkey(struct crypto_skcipher *cipher,
 
 	ctx->keylen = keylen;
 	memcpy_toio(ctx->dev->reg + RK_CRYPTO_TDES_KEY1_0, key, keylen);
-	return 0;
+
+	return crypto_skcipher_setkey(ctx->fallback_tfm, key, keylen);
 }
 
 static int rk_tdes_setkey(struct crypto_skcipher *cipher,
@@ -69,7 +128,7 @@ static int rk_tdes_setkey(struct crypto_skcipher *cipher,
 
 	ctx->keylen = keylen;
 	memcpy_toio(ctx->dev->reg + RK_CRYPTO_TDES_KEY1_0, key, keylen);
-	return 0;
+	return crypto_skcipher_setkey(ctx->fallback_tfm, key, keylen);
 }
 
 static int rk_aes_ecb_encrypt(struct skcipher_request *req)
@@ -394,6 +453,7 @@ static int rk_ablk_init_tfm(struct crypto_skcipher *tfm)
 {
 	struct rk_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
+	const char *name = crypto_tfm_alg_name(&tfm->base);
 	struct rk_crypto_tmp *algt;
 
 	algt = container_of(alg, struct rk_crypto_tmp, alg.skcipher);
@@ -407,6 +467,16 @@ static int rk_ablk_init_tfm(struct crypto_skcipher *tfm)
 	if (!ctx->dev->addr_vir)
 		return -ENOMEM;
 
+	ctx->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
+	if (IS_ERR(ctx->fallback_tfm)) {
+		dev_err(ctx->dev->dev, "ERROR: Cannot allocate fallback for %s %ld\n",
+			name, PTR_ERR(ctx->fallback_tfm));
+		return PTR_ERR(ctx->fallback_tfm);
+	}
+
+	tfm->reqsize = sizeof(struct rk_cipher_rctx) +
+		crypto_skcipher_reqsize(ctx->fallback_tfm);
+
 	return 0;
 }
 
@@ -415,6 +485,7 @@ static void rk_ablk_exit_tfm(struct crypto_skcipher *tfm)
 	struct rk_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
 
 	free_page((unsigned long)ctx->dev->addr_vir);
+	crypto_free_skcipher(ctx->fallback_tfm);
 }
 
 struct rk_crypto_tmp rk_ecb_aes_alg = {
@@ -423,7 +494,7 @@ struct rk_crypto_tmp rk_ecb_aes_alg = {
 		.base.cra_name		= "ecb(aes)",
 		.base.cra_driver_name	= "ecb-aes-rk",
 		.base.cra_priority	= 300,
-		.base.cra_flags		= CRYPTO_ALG_ASYNC,
+		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
 		.base.cra_blocksize	= AES_BLOCK_SIZE,
 		.base.cra_ctxsize	= sizeof(struct rk_cipher_ctx),
 		.base.cra_alignmask	= 0x0f,
@@ -445,7 +516,7 @@ struct rk_crypto_tmp rk_cbc_aes_alg = {
 		.base.cra_name		= "cbc(aes)",
 		.base.cra_driver_name	= "cbc-aes-rk",
 		.base.cra_priority	= 300,
-		.base.cra_flags		= CRYPTO_ALG_ASYNC,
+		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
 		.base.cra_blocksize	= AES_BLOCK_SIZE,
 		.base.cra_ctxsize	= sizeof(struct rk_cipher_ctx),
 		.base.cra_alignmask	= 0x0f,
@@ -468,7 +539,7 @@ struct rk_crypto_tmp rk_ecb_des_alg = {
 		.base.cra_name		= "ecb(des)",
 		.base.cra_driver_name	= "ecb-des-rk",
 		.base.cra_priority	= 300,
-		.base.cra_flags		= CRYPTO_ALG_ASYNC,
+		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
 		.base.cra_blocksize	= DES_BLOCK_SIZE,
 		.base.cra_ctxsize	= sizeof(struct rk_cipher_ctx),
 		.base.cra_alignmask	= 0x07,
@@ -490,7 +561,7 @@ struct rk_crypto_tmp rk_cbc_des_alg = {
 		.base.cra_name		= "cbc(des)",
 		.base.cra_driver_name	= "cbc-des-rk",
 		.base.cra_priority	= 300,
-		.base.cra_flags		= CRYPTO_ALG_ASYNC,
+		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
 		.base.cra_blocksize	= DES_BLOCK_SIZE,
 		.base.cra_ctxsize	= sizeof(struct rk_cipher_ctx),
 		.base.cra_alignmask	= 0x07,
@@ -513,7 +584,7 @@ struct rk_crypto_tmp rk_ecb_des3_ede_alg = {
 		.base.cra_name		= "ecb(des3_ede)",
 		.base.cra_driver_name	= "ecb-des3-ede-rk",
 		.base.cra_priority	= 300,
-		.base.cra_flags		= CRYPTO_ALG_ASYNC,
+		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
 		.base.cra_blocksize	= DES_BLOCK_SIZE,
 		.base.cra_ctxsize	= sizeof(struct rk_cipher_ctx),
 		.base.cra_alignmask	= 0x07,
@@ -535,7 +606,7 @@ struct rk_crypto_tmp rk_cbc_des3_ede_alg = {
 		.base.cra_name		= "cbc(des3_ede)",
 		.base.cra_driver_name	= "cbc-des3-ede-rk",
 		.base.cra_priority	= 300,
-		.base.cra_flags		= CRYPTO_ALG_ASYNC,
+		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
 		.base.cra_blocksize	= DES_BLOCK_SIZE,
 		.base.cra_ctxsize	= sizeof(struct rk_cipher_ctx),
 		.base.cra_alignmask	= 0x07,