crypto: starfive - Align rsa input data to 32-bit

Hardware expects RSA input plain/ciphertext to be 32-bit aligned.
Set fixed length for preallocated buffer to the maximum supported
keysize of the hardware and shift input text accordingly.
Signed-off-by: Jia Jie Ho <jiajie.ho@starfivetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/starfive/jh7110-cryp.h

@@ -30,6 +30,7 @@
 #define MAX_KEY_SIZE				SHA512_BLOCK_SIZE
 #define STARFIVE_AES_IV_LEN			AES_BLOCK_SIZE
 #define STARFIVE_AES_CTR_LEN			AES_BLOCK_SIZE
+#define STARFIVE_RSA_MAX_KEYSZ			256
 
 union starfive_aes_csr {
 	u32 v;
@@ -222,7 +223,7 @@ struct starfive_cryp_request_ctx {
 	unsigned int				digsize;
 	unsigned long				in_sg_len;
 	unsigned char				*adata;
-	u8 rsa_data[] __aligned(sizeof(u32));
+	u8 rsa_data[STARFIVE_RSA_MAX_KEYSZ] __aligned(sizeof(u32));
 };
 
 struct starfive_cryp_dev *starfive_cryp_find_dev(struct starfive_cryp_ctx *ctx);

drivers/crypto/starfive/jh7110-rsa.c

@@ -31,7 +31,6 @@
 /* A * A * R mod N ==> A */
 #define CRYPTO_CMD_AARN			0x7
 
-#define STARFIVE_RSA_MAX_KEYSZ		256
 #define STARFIVE_RSA_RESET		0x2
 
 static inline int starfive_pka_wait_done(struct starfive_cryp_ctx *ctx)
@@ -74,7 +73,7 @@ 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, 4) / 4) - 1;
 	int loop;
 	u32 temp;
 	u8 opsize;
@@ -251,12 +250,17 @@ 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);
 
+	if (!IS_ALIGNED(rctx->total, sizeof(u32))) {
+		shift = sizeof(u32) - (rctx->total & 0x3);
+		memset(rctx->rsa_data, 0, shift);
+	}
+
 	rctx->total = sg_copy_to_buffer(rctx->in_sg, rctx->nents,
-					rctx->rsa_data, rctx->total);
+					rctx->rsa_data + shift, rctx->total);
 
 	if (enc) {
 		key->bitlen = key->e_bitlen;