1 files changed, 37 insertions, 10 deletions

diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
index 6bcd9157a02f..189bf0a45649 100644
--- a/drivers/crypto/mxs-dcp.c
+++ b/drivers/crypto/mxs-dcp.c
@@ -28,9 +28,24 @@
 
 #define DCP_MAX_CHANS	4
 #define DCP_BUF_SZ	PAGE_SIZE
+#define DCP_SHA_PAY_SZ  64
 
 #define DCP_ALIGNMENT	64
 
+/*
+ * Null hashes to align with hw behavior on imx6sl and ull
+ * these are flipped for consistency with hw output
+ */
+const uint8_t sha1_null_hash[] =
+	"\x09\x07\xd8\xaf\x90\x18\x60\x95\xef\xbf"
+	"\x55\x32\x0d\x4b\x6b\x5e\xee\xa3\x39\xda";
+
+const uint8_t sha256_null_hash[] =
+	"\x55\xb8\x52\x78\x1b\x99\x95\xa4"
+	"\x4c\x93\x9b\x64\xe4\x41\xae\x27"
+	"\x24\xb9\x6f\x99\xc8\xf4\xfb\x9a"
+	"\x14\x1c\xfc\x98\x42\xc4\xb0\xe3";
+
 /* DCP DMA descriptor. */
 struct dcp_dma_desc {
 	uint32_t	next_cmd_addr;
@@ -48,6 +63,7 @@ struct dcp_coherent_block {
 	uint8_t			aes_in_buf[DCP_BUF_SZ];
 	uint8_t			aes_out_buf[DCP_BUF_SZ];
 	uint8_t			sha_in_buf[DCP_BUF_SZ];
+	uint8_t			sha_out_buf[DCP_SHA_PAY_SZ];
 
 	uint8_t			aes_key[2 * AES_KEYSIZE_128];
 
@@ -513,8 +529,6 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
-	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
-
 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
 
 	dma_addr_t digest_phys = 0;
@@ -536,10 +550,23 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
 	desc->payload = 0;
 	desc->status = 0;
 
+	/*
+	 * Align driver with hw behavior when generating null hashes
+	 */
+	if (rctx->init && rctx->fini && desc->size == 0) {
+		struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
+		const uint8_t *sha_buf =
+			(actx->alg == MXS_DCP_CONTROL1_HASH_SELECT_SHA1) ?
+			sha1_null_hash : sha256_null_hash;
+		memcpy(sdcp->coh->sha_out_buf, sha_buf, halg->digestsize);
+		ret = 0;
+		goto done_run;
+	}
+
 	/* Set HASH_TERM bit for last transfer block. */
 	if (rctx->fini) {
-		digest_phys = dma_map_single(sdcp->dev, req->result,
-					     halg->digestsize, DMA_FROM_DEVICE);
+		digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
+					     DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
 		desc->payload = digest_phys;
 	}
@@ -547,9 +574,10 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
 	ret = mxs_dcp_start_dma(actx);
 
 	if (rctx->fini)
-		dma_unmap_single(sdcp->dev, digest_phys, halg->digestsize,
+		dma_unmap_single(sdcp->dev, digest_phys, DCP_SHA_PAY_SZ,
 				 DMA_FROM_DEVICE);
 
+done_run:
 	dma_unmap_single(sdcp->dev, buf_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
 
 	return ret;
@@ -567,6 +595,7 @@ static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
 	const int nents = sg_nents(req->src);
 
 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
+	uint8_t *out_buf = sdcp->coh->sha_out_buf;
 
 	uint8_t *src_buf;
 
@@ -621,11 +650,9 @@ static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
 
 		actx->fill = 0;
 
-		/* For some reason, the result is flipped. */
-		for (i = 0; i < halg->digestsize / 2; i++) {
-			swap(req->result[i],
-			     req->result[halg->digestsize - i - 1]);
-		}
+		/* For some reason the result is flipped */
+		for (i = 0; i < halg->digestsize; i++)
+			req->result[i] = out_buf[halg->digestsize - i - 1];
 	}
 
 	return 0;