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@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ for more details. This change should make CAAM's hwrng driver good enough to have 1024 quality rating. Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx> Cc: Chris Healy <cphealy@xxxxxxxxx> Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> Cc: Horia Geantă <horia.geanta@xxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Iuliana Prodan <iuliana.prodan@xxxxxxx> Cc: linux-crypto@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-imx@xxxxxxx --- 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
