In order to follow recommendation in SP800-90C (section "9.4 The
Oversampling-NRBG Construction") limit the output of "generate" JD
submitted to CAAM. See
https://lore.kernel.org/linux-crypto/VI1PR0402MB3485EF10976A4A69F90E5B0F98580@VI1PR0402MB3485.eurprd04.prod.outlook.com/
for more details.
This change should make CAAM's hwrng driver good enough to have 1024
quality rating.
Signed-off-by: Andrey Smirnov <[email protected]>
Cc: Chris Healy <[email protected]>
Cc: Lucas Stach <[email protected]>
Cc: Horia Geantă <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Iuliana Prodan <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
drivers/crypto/caam/caamrng.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
index 62f3a69ae837..c0981fce68b7 100644
--- a/drivers/crypto/caam/caamrng.c
+++ b/drivers/crypto/caam/caamrng.c
@@ -23,9 +23,9 @@
#include "error.h"
/* length of descriptors */
-#define CAAM_RNG_MAX_FIFO_STORE_SIZE U16_MAX
+#define CAAM_RNG_MAX_FIFO_STORE_SIZE 16
-#define CAAM_RNG_FIFO_LEN SZ_32K /* Must be a multiple of 2 */
+#define CAAM_RNG_FIFO_LEN 64 /* Must be a multiple of 2 */
/*
* See caam_init_desc()
@@ -128,7 +128,7 @@ static void caam_rng_fill_async(struct caam_rng_ctx *ctx)
sg_init_table(sg, ARRAY_SIZE(sg));
nents = kfifo_dma_in_prepare(&ctx->fifo, sg, ARRAY_SIZE(sg),
- CAAM_RNG_FIFO_LEN);
+ CAAM_RNG_MAX_FIFO_STORE_SIZE);
if (!nents)
return;
@@ -246,6 +246,7 @@ int caam_rng_init(struct device *ctrldev)
ctx->rng.init = caam_init;
ctx->rng.cleanup = caam_cleanup;
ctx->rng.read = caam_read;
+ ctx->rng.quality = 1024;
dev_info(ctrldev, "registering rng-caam\n");
--
2.21.0