crypto: ccp - Cleanup scatterlist usage

Cleanup up the usage of scatterlists to make the code cleaner
and avoid extra memory allocations when not needed.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 33 insertions, 26 deletions

diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
index 398832c2414a..646c8d1bd03c 100644
--- a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
@@ -125,8 +125,10 @@ static int ccp_do_cmac_update(struct ahash_request *req, unsigned int nbytes,
                 sg_init_one(&rctx->pad_sg, rctx->pad, pad_length);
                 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg);
         }
-        if (sg)
+        if (sg) {
                 sg_mark_end(sg);
+                sg = rctx->data_sg.sgl;
+        }
 
         /* Initialize the K1/K2 scatterlist */
         if (final)
@@ -143,7 +145,7 @@ static int ccp_do_cmac_update(struct ahash_request *req, unsigned int nbytes,
         rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
         rctx->cmd.u.aes.iv = &rctx->iv_sg;
         rctx->cmd.u.aes.iv_len = AES_BLOCK_SIZE;
-        rctx->cmd.u.aes.src = (sg) ? rctx->data_sg.sgl : NULL;
+        rctx->cmd.u.aes.src = sg;
         rctx->cmd.u.aes.src_len = rctx->hash_cnt;
         rctx->cmd.u.aes.dst = NULL;
         rctx->cmd.u.aes.cmac_key = cmac_key_sg;
diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
index 0571940cfdf9..bf913cbb3e96 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -122,7 +122,6 @@ static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
                              unsigned int final)
 {
         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
-        struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
         struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
         struct scatterlist *sg;
         unsigned int block_size =
@@ -153,35 +152,32 @@ static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
         /* Initialize the context scatterlist */
         sg_init_one(&rctx->ctx_sg, rctx->ctx, sizeof(rctx->ctx));
 
-        /* Build the data scatterlist table - allocate enough entries for all
-         * possible data pieces (hmac ipad, buffer, input data)
-         */
-        sg_count = (nbytes) ? sg_nents(req->src) + 2 : 2;
-        gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
-                GFP_KERNEL : GFP_ATOMIC;
-        ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
-        if (ret)
-                return ret;
-
         sg = NULL;
-        if (rctx->first && ctx->u.sha.key_len) {
-                rctx->hash_cnt += block_size;
-
-                sg_init_one(&rctx->pad_sg, ctx->u.sha.ipad, block_size);
-                sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg);
-        }
+        if (rctx->buf_count && nbytes) {
+                /* Build the data scatterlist table - allocate enough entries
+                 * for both data pieces (buffer and input data)
+                 */
+                gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
+                        GFP_KERNEL : GFP_ATOMIC;
+                sg_count = sg_nents(req->src) + 1;
+                ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
+                if (ret)
+                        return ret;
 
-        if (rctx->buf_count) {
                 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
                 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg);
-        }
-
-        if (nbytes)
                 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);
-
-        if (sg)
                 sg_mark_end(sg);
 
+                sg = rctx->data_sg.sgl;
+        } else if (rctx->buf_count) {
+                sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
+
+                sg = &rctx->buf_sg;
+        } else if (nbytes) {
+                sg = req->src;
+        }
+
         rctx->msg_bits += (rctx->hash_cnt << 3);        /* Total in bits */
 
         memset(&rctx->cmd, 0, sizeof(rctx->cmd));
@@ -190,7 +186,7 @@ static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
         rctx->cmd.u.sha.type = rctx->type;
         rctx->cmd.u.sha.ctx = &rctx->ctx_sg;
         rctx->cmd.u.sha.ctx_len = sizeof(rctx->ctx);
-        rctx->cmd.u.sha.src = (sg) ? rctx->data_sg.sgl : NULL;
+        rctx->cmd.u.sha.src = sg;
         rctx->cmd.u.sha.src_len = rctx->hash_cnt;
         rctx->cmd.u.sha.final = rctx->final;
         rctx->cmd.u.sha.msg_bits = rctx->msg_bits;
@@ -205,9 +201,12 @@ static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
 static int ccp_sha_init(struct ahash_request *req)
 {
         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+        struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
         struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
         struct ccp_crypto_ahash_alg *alg =
                 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));
+        unsigned int block_size =
+                crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
 
         memset(rctx, 0, sizeof(*rctx));
 
@@ -215,6 +214,12 @@ static int ccp_sha_init(struct ahash_request *req)
         rctx->type = alg->type;
         rctx->first = 1;
 
+        if (ctx->u.sha.key_len) {
+                /* Buffer the HMAC key for first update */
+                memcpy(rctx->buf, ctx->u.sha.ipad, block_size);
+                rctx->buf_count = block_size;
+        }
+
         return 0;
 }