crypto: sun4i-ss - fallback when length is not multiple of blocksize

sun4i-ss does not handle requests when length are not a multiple of
blocksize.
This patch adds a fallback for that case.

Fixes: 6298e948215f ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

3 files changed, 67 insertions, 9 deletions

diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c b/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
index 4b60f8fdd1c8..b060a0810934 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
@@ -129,6 +129,8 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 	struct scatterlist *out_sg = areq->dst;
 	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 	struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
+	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
+	struct sun4i_ss_alg_template *algt;
 	u32 mode = ctx->mode;
 	/* when activating SS, the default FIFO space is SS_RX_DEFAULT(32) */
 	u32 rx_cnt = SS_RX_DEFAULT;
@@ -148,6 +150,7 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 	unsigned int obo = 0;	/* offset in bufo*/
 	unsigned int obl = 0;	/* length of data in bufo */
 	unsigned long flags;
+	bool need_fallback;
 
 	if (!areq->cryptlen)
 		return 0;
@@ -157,6 +160,10 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 		return -EINVAL;
 	}
 
+	algt = container_of(alg, struct sun4i_ss_alg_template, alg.crypto);
+	if (areq->cryptlen % algt->alg.crypto.base.cra_blocksize)
+		need_fallback = true;
+
 	/*
 	 * if we have only SGs with size multiple of 4,
 	 * we can use the SS optimized function
@@ -172,9 +179,24 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 		out_sg = sg_next(out_sg);
 	}
 
-	if (no_chunk == 1)
+	if (no_chunk == 1 && !need_fallback)
 		return sun4i_ss_opti_poll(areq);
 
+	if (need_fallback) {
+		SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, op->fallback_tfm);
+		skcipher_request_set_sync_tfm(subreq, op->fallback_tfm);
+		skcipher_request_set_callback(subreq, areq->base.flags, NULL,
+					      NULL);
+		skcipher_request_set_crypt(subreq, areq->src, areq->dst,
+					   areq->cryptlen, areq->iv);
+		if (ctx->mode & SS_DECRYPTION)
+			err = crypto_skcipher_decrypt(subreq);
+		else
+			err = crypto_skcipher_encrypt(subreq);
+		skcipher_request_zero(subreq);
+		return err;
+	}
+
 	spin_lock_irqsave(&ss->slock, flags);
 
 	for (i = 0; i < op->keylen; i += 4)
@@ -448,6 +470,7 @@ int sun4i_ss_cipher_init(struct crypto_tfm *tfm)
 {
 	struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
 	struct sun4i_ss_alg_template *algt;
+	const char *name = crypto_tfm_alg_name(tfm);
 
 	memset(op, 0, sizeof(struct sun4i_tfm_ctx));
 
@@ -458,9 +481,22 @@ int sun4i_ss_cipher_init(struct crypto_tfm *tfm)
 	crypto_skcipher_set_reqsize(__crypto_skcipher_cast(tfm),
 				    sizeof(struct sun4i_cipher_req_ctx));
 
+	op->fallback_tfm = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
+	if (IS_ERR(op->fallback_tfm)) {
+		dev_err(op->ss->dev, "ERROR: Cannot allocate fallback for %s %ld\n",
+			name, PTR_ERR(op->fallback_tfm));
+		return PTR_ERR(op->fallback_tfm);
+	}
+
 	return 0;
 }
 
+void sun4i_ss_cipher_exit(struct crypto_tfm *tfm)
+{
+	struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
+	crypto_free_sync_skcipher(op->fallback_tfm);
+}
+
 /* check and set the AES key, prepare the mode to be used */
 int sun4i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			unsigned int keylen)
@@ -485,7 +521,11 @@ int sun4i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 	}
 	op->keylen = keylen;
 	memcpy(op->key, key, keylen);
-	return 0;
+
+	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
+	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
+
+	return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen);
 }
 
 /* check and set the DES key, prepare the mode to be used */
@@ -515,7 +555,11 @@ int sun4i_ss_des_setkey(struct crypto_skcipher *tfm, const u8 *key,
 
 	op->keylen = keylen;
 	memcpy(op->key, key, keylen);
-	return 0;
+
+	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
+	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
+
+	return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen);
 }
 
 /* check and set the 3DES key, prepare the mode to be used */
@@ -531,5 +575,10 @@ int sun4i_ss_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
 
 	op->keylen = keylen;
 	memcpy(op->key, key, keylen);
-	return 0;
+
+	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
+	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
+
+	return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen);
+
 }
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-core.c b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
index 1fad2b4b58c5..05b3d3c32f6d 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss-core.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
@@ -92,11 +92,12 @@ static struct sun4i_ss_alg_template ss_algs[] = {
 			.cra_driver_name = "cbc-aes-sun4i-ss",
 			.cra_priority = 300,
 			.cra_blocksize = AES_BLOCK_SIZE,
-			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY,
+			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_NEED_FALLBACK,
 			.cra_ctxsize = sizeof(struct sun4i_tfm_ctx),
 			.cra_module = THIS_MODULE,
 			.cra_alignmask = 3,
 			.cra_init = sun4i_ss_cipher_init,
+			.cra_exit = sun4i_ss_cipher_exit,
 		}
 	}
 },
@@ -112,11 +113,12 @@ static struct sun4i_ss_alg_template ss_algs[] = {
 			.cra_driver_name = "ecb-aes-sun4i-ss",
 			.cra_priority = 300,
 			.cra_blocksize = AES_BLOCK_SIZE,
-			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY,
+			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_NEED_FALLBACK,
 			.cra_ctxsize = sizeof(struct sun4i_tfm_ctx),
 			.cra_module = THIS_MODULE,
 			.cra_alignmask = 3,
 			.cra_init = sun4i_ss_cipher_init,
+			.cra_exit = sun4i_ss_cipher_exit,
 		}
 	}
 },
@@ -133,11 +135,12 @@ static struct sun4i_ss_alg_template ss_algs[] = {
 			.cra_driver_name = "cbc-des-sun4i-ss",
 			.cra_priority = 300,
 			.cra_blocksize = DES_BLOCK_SIZE,
-			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY,
+			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_NEED_FALLBACK,
 			.cra_ctxsize = sizeof(struct sun4i_req_ctx),
 			.cra_module = THIS_MODULE,
 			.cra_alignmask = 3,
 			.cra_init = sun4i_ss_cipher_init,
+			.cra_exit = sun4i_ss_cipher_exit,
 		}
 	}
 },
@@ -153,11 +156,12 @@ static struct sun4i_ss_alg_template ss_algs[] = {
 			.cra_driver_name = "ecb-des-sun4i-ss",
 			.cra_priority = 300,
 			.cra_blocksize = DES_BLOCK_SIZE,
-			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY,
+			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_NEED_FALLBACK,
 			.cra_ctxsize = sizeof(struct sun4i_req_ctx),
 			.cra_module = THIS_MODULE,
 			.cra_alignmask = 3,
 			.cra_init = sun4i_ss_cipher_init,
+			.cra_exit = sun4i_ss_cipher_exit,
 		}
 	}
 },
@@ -174,11 +178,12 @@ static struct sun4i_ss_alg_template ss_algs[] = {
 			.cra_driver_name = "cbc-des3-sun4i-ss",
 			.cra_priority = 300,
 			.cra_blocksize = DES3_EDE_BLOCK_SIZE,
-			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY,
+			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_NEED_FALLBACK,
 			.cra_ctxsize = sizeof(struct sun4i_req_ctx),
 			.cra_module = THIS_MODULE,
 			.cra_alignmask = 3,
 			.cra_init = sun4i_ss_cipher_init,
+			.cra_exit = sun4i_ss_cipher_exit,
 		}
 	}
 },
@@ -194,10 +199,12 @@ static struct sun4i_ss_alg_template ss_algs[] = {
 			.cra_driver_name = "ecb-des3-sun4i-ss",
 			.cra_priority = 300,
 			.cra_blocksize = DES3_EDE_BLOCK_SIZE,
+			.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_NEED_FALLBACK,
 			.cra_ctxsize = sizeof(struct sun4i_req_ctx),
 			.cra_module = THIS_MODULE,
 			.cra_alignmask = 3,
 			.cra_init = sun4i_ss_cipher_init,
+			.cra_exit = sun4i_ss_cipher_exit,
 		}
 	}
 },
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss.h b/drivers/crypto/sunxi-ss/sun4i-ss.h
index f3ac90692ac6..8c4ec9e93565 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss.h
+++ b/drivers/crypto/sunxi-ss/sun4i-ss.h
@@ -161,6 +161,7 @@ struct sun4i_tfm_ctx {
 	u32 keylen;
 	u32 keymode;
 	struct sun4i_ss_ctx *ss;
+	struct crypto_sync_skcipher *fallback_tfm;
 };
 
 struct sun4i_cipher_req_ctx {
@@ -203,6 +204,7 @@ int sun4i_ss_ecb_des3_encrypt(struct skcipher_request *areq);
 int sun4i_ss_ecb_des3_decrypt(struct skcipher_request *areq);
 
 int sun4i_ss_cipher_init(struct crypto_tfm *tfm);
+void sun4i_ss_cipher_exit(struct crypto_tfm *tfm);
 int sun4i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			unsigned int keylen);
 int sun4i_ss_des_setkey(struct crypto_skcipher *tfm, const u8 *key,