Commit 2be0d806 authored by Victoria Milhoan (b42089)'s avatar Victoria Milhoan (b42089) Committed by Herbert Xu
Browse files

crypto: caam - add a test for the RNG 



CAAM includes a Random Number Generator.  This change adds
a kernel configuration option to test the RNG's capabilities via the
hw_random framework.

Signed-off-by: default avatarVictoria Milhoan <vicki.milhoan@freescale.com>
Signed-off-by: default avatarDan Douglass <dan.douglass@nxp.com>
Signed-off-by: default avatarVipul Kumar <vipul_kumar@mentor.com>
Signed-off-by: default avatarHoria Geantă <horia.geanta@nxp.com>
Signed-off-by: default avatarMeenakshi Aggarwal <meenakshi.aggarwal@nxp.com>
Reviewed-by: default avatarGaurav Jain <gaurav.jain@nxp.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent ef492d08

drivers/crypto/caam/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -162,6 +162,15 @@ config CRYPTO_DEV_FSL_CAAM_PRNG_API 
config CRYPTO_DEV_FSL_CAAM_BLOB_GEN

	bool



config CRYPTO_DEV_FSL_CAAM_RNG_TEST

	bool "Test caam rng"

	select CRYPTO_DEV_FSL_CAAM_RNG_API

	help

	  Selecting this will enable a self-test to run for the

	  caam RNG.

	  This test is several minutes long and executes

	  just before the RNG is registered with the hw_random API.



endif # CRYPTO_DEV_FSL_CAAM_JR



endif # CRYPTO_DEV_FSL_CAAM

drivers/crypto/caam/caamrng.c

+48 −0
Original line number Diff line number Diff line
@@ -172,6 +172,50 @@ static void caam_cleanup(struct hwrng *rng) 
	kfifo_free(&ctx->fifo);

}



#ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_TEST

static inline void test_len(struct hwrng *rng, size_t len, bool wait)

{

	u8 *buf;

	int read_len;

	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);

	struct device *dev = ctx->ctrldev;



	buf = kcalloc(CAAM_RNG_MAX_FIFO_STORE_SIZE, sizeof(u8), GFP_KERNEL);



	while (len > 0) {

		read_len = rng->read(rng, buf, len, wait);



		if (read_len < 0 || (read_len == 0 && wait)) {

			dev_err(dev, "RNG Read FAILED received %d bytes\n",

				read_len);

			kfree(buf);

			return;

		}



		print_hex_dump_debug("random bytes@: ",

			DUMP_PREFIX_ADDRESS, 16, 4,

			buf, read_len, 1);



		len = len - read_len;

	}



	kfree(buf);

}



static inline void test_mode_once(struct hwrng *rng, bool wait)

{

	test_len(rng, 32, wait);

	test_len(rng, 64, wait);

	test_len(rng, 128, wait);

}



static void self_test(struct hwrng *rng)

{

	pr_info("Executing RNG SELF-TEST with wait\n");

	test_mode_once(rng, true);

}

#endif



static int caam_init(struct hwrng *rng)

{

	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
@@ -258,6 +302,10 @@ int caam_rng_init(struct device *ctrldev) 
		return ret;

	}



#ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_TEST

	self_test(&ctx->rng);

#endif



	devres_close_group(ctrldev, caam_rng_init);

	return 0;

}