Hardware expects RSA input plain/ciphertext to be 32-bit aligned.
Allocate aligned buffer and shift data accordingly.

Signed-off-by: Jia Jie Ho <jiajie.ho@starfivetech.com>
---
 drivers/crypto/starfive/jh7110-cryp.h |  3 +--
 drivers/crypto/starfive/jh7110-rsa.c  | 17 ++++++++++-------
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/crypto/starfive/jh7110-cryp.h b/drivers/crypto/starfive/jh7110-cryp.h
index 494a74f52706..eeb4e2b9655f 100644
--- a/drivers/crypto/starfive/jh7110-cryp.h
+++ b/drivers/crypto/starfive/jh7110-cryp.h
@@ -217,12 +217,11 @@ struct starfive_cryp_request_ctx {
 	struct scatterlist			*out_sg;
 	struct ahash_request			ahash_fbk_req;
 	size_t					total;
-	size_t					nents;
 	unsigned int				blksize;
 	unsigned int				digsize;
 	unsigned long				in_sg_len;
 	unsigned char				*adata;
-	u8 rsa_data[] __aligned(sizeof(u32));
+	u8					*rsa_data;
 };
 
 struct starfive_cryp_dev *starfive_cryp_find_dev(struct starfive_cryp_ctx *ctx);
diff --git a/drivers/crypto/starfive/jh7110-rsa.c b/drivers/crypto/starfive/jh7110-rsa.c
index 33093ba4b13a..8e4ea607102a 100644
--- a/drivers/crypto/starfive/jh7110-rsa.c
+++ b/drivers/crypto/starfive/jh7110-rsa.c
@@ -74,14 +74,13 @@ static int starfive_rsa_montgomery_form(struct starfive_cryp_ctx *ctx,
 {
 	struct starfive_cryp_dev *cryp = ctx->cryp;
 	struct starfive_cryp_request_ctx *rctx = ctx->rctx;
-	int count = rctx->total / sizeof(u32) - 1;
+	int count = (ALIGN(rctx->total, sizeof(u32)) >> 2) - 1;
 	int loop;
 	u32 temp;
 	u8 opsize;
 
 	opsize = (bit_len - 1) >> 5;
 	rctx->csr.pka.v = 0;
-
 	writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
 
 	for (loop = 0; loop <= opsize; loop++)
@@ -117,7 +116,6 @@ static int starfive_rsa_montgomery_form(struct starfive_cryp_ctx *ctx,
 		rctx->csr.pka.cmd = CRYPTO_CMD_AERN;
 		rctx->csr.pka.start = 1;
 		rctx->csr.pka.ie = 1;
-
 		writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
 
 		if (starfive_pka_wait_done(ctx))
@@ -251,12 +249,17 @@ static int starfive_rsa_enc_core(struct starfive_cryp_ctx *ctx, int enc)
 	struct starfive_cryp_dev *cryp = ctx->cryp;
 	struct starfive_cryp_request_ctx *rctx = ctx->rctx;
 	struct starfive_rsa_key *key = &ctx->rsa_key;
-	int ret = 0;
+	int ret = 0, shift = 0;
 
 	writel(STARFIVE_RSA_RESET, cryp->base + STARFIVE_PKA_CACR_OFFSET);
 
-	rctx->total = sg_copy_to_buffer(rctx->in_sg, rctx->nents,
-					rctx->rsa_data, rctx->total);
+	rctx->rsa_data = kzalloc(key->key_sz, GFP_KERNEL);
+
+	if (!IS_ALIGNED(rctx->total, sizeof(u32)))
+		shift = sizeof(u32) - (rctx->total & 0x3);
+
+	rctx->total = sg_copy_to_buffer(rctx->in_sg, sg_nents(rctx->in_sg),
+					rctx->rsa_data + shift, rctx->total);
 
 	if (enc) {
 		key->bitlen = key->e_bitlen;
@@ -275,6 +278,7 @@ static int starfive_rsa_enc_core(struct starfive_cryp_ctx *ctx, int enc)
 		       rctx->rsa_data, key->key_sz, 0, 0);
 
 err_rsa_crypt:
+	kfree(rctx->rsa_data);
 	writel(STARFIVE_RSA_RESET, cryp->base + STARFIVE_PKA_CACR_OFFSET);
 	return ret;
 }
@@ -305,7 +309,6 @@ static int starfive_rsa_enc(struct akcipher_request *req)
 	rctx->in_sg = req->src;
 	rctx->out_sg = req->dst;
 	rctx->total = req->src_len;
-	rctx->nents = sg_nents(rctx->in_sg);
 	ctx->rctx = rctx;
 
 	return starfive_rsa_enc_core(ctx, 1);
-- 
2.43.0

On Wed, May 29, 2024 at 08:25:53AM +0800, Jia Jie Ho wrote:
> Hardware expects RSA input plain/ciphertext to be 32-bit aligned.
> Allocate aligned buffer and shift data accordingly.
> 
> Signed-off-by: Jia Jie Ho <jiajie.ho@starfivetech.com>
> ---
>  drivers/crypto/starfive/jh7110-cryp.h |  3 +--
>  drivers/crypto/starfive/jh7110-rsa.c  | 17 ++++++++++-------
>  2 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/crypto/starfive/jh7110-cryp.h b/drivers/crypto/starfive/jh7110-cryp.h
> index 494a74f52706..eeb4e2b9655f 100644
> --- a/drivers/crypto/starfive/jh7110-cryp.h
> +++ b/drivers/crypto/starfive/jh7110-cryp.h
> @@ -217,12 +217,11 @@ struct starfive_cryp_request_ctx {
>  	struct scatterlist			*out_sg;
>  	struct ahash_request			ahash_fbk_req;
>  	size_t					total;
> -	size_t					nents;
>  	unsigned int				blksize;
>  	unsigned int				digsize;
>  	unsigned long				in_sg_len;
>  	unsigned char				*adata;
> -	u8 rsa_data[] __aligned(sizeof(u32));
> +	u8					*rsa_data;

You didn't explain why this is moving from a pre-allocated buffer
to one that's allocated on the run.  It would appear that there is
no reason why you can't build the extra space used for shifting
into reqsize.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt