[PATCH 01/12] crypto: axis - do not DMA to ahash_request.result

From: Vincent Whitchurch
Date: Tue Jan 10 2023 - 08:51:49 EST


From: Lars Persson <larper@xxxxxxxx>

The crypto API does not promise that the result pointer is suitable
for DMA. Use an intermediate result buffer and let the CPU copy the
digest to the ahash_request.

Signed-off-by: Lars Persson <larper@xxxxxxxx>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
---
drivers/crypto/axis/artpec6_crypto.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/axis/artpec6_crypto.c b/drivers/crypto/axis/artpec6_crypto.c
index 51c66afbe677..87af44ac3e64 100644
--- a/drivers/crypto/axis/artpec6_crypto.c
+++ b/drivers/crypto/axis/artpec6_crypto.c
@@ -276,6 +276,7 @@ enum artpec6_crypto_hash_flags {
HASH_FLAG_FINALIZE = 8,
HASH_FLAG_HMAC = 16,
HASH_FLAG_UPDATE_KEY = 32,
+ HASH_FLAG_FINALIZED = 64,
};

struct artpec6_crypto_req_common {
@@ -1493,12 +1494,15 @@ static int artpec6_crypto_prepare_hash(struct ahash_request *areq)
return error;

/* Descriptor for the final result */
- error = artpec6_crypto_setup_in_descr(common, areq->result,
+ error = artpec6_crypto_setup_in_descr(common,
+ req_ctx->digeststate,
digestsize,
true);
if (error)
return error;

+ req_ctx->hash_flags |= HASH_FLAG_FINALIZED;
+
} else { /* This is not the final operation for this request */
if (!run_hw)
return ARTPEC6_CRYPTO_PREPARE_HASH_NO_START;
@@ -2216,6 +2220,14 @@ static void artpec6_crypto_complete_aead(struct crypto_async_request *req)

static void artpec6_crypto_complete_hash(struct crypto_async_request *req)
{
+ struct ahash_request *areq = container_of(req, struct ahash_request, base);
+ struct artpec6_hash_request_context *ctx = ahash_request_ctx(areq);
+ struct crypto_ahash *ahash = crypto_ahash_reqtfm(areq);
+ size_t digestsize = crypto_ahash_digestsize(ahash);
+
+ if (ctx->hash_flags & HASH_FLAG_FINALIZED)
+ memcpy(areq->result, ctx->digeststate, digestsize);
+
req->complete(req, 0);
}

--
2.34.1