From 387a26c56933fbfd0fa211ad5347d48d08695ea0 Mon Sep 17 00:00:00 2001 From: "Victoria Milhoan (b42089)" Date: Fri, 17 Oct 2014 16:30:56 -0700 Subject: [PATCH] MLK-9769-8 crypto: caam - add a test for the RNG MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Freescale's 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: Victoria Milhoan Signed-off-by: Dan Douglass Signed-off-by: Vipul Kumar (cherry picked from commit 05fba1bb857d5329fdcf79e736643fce0944a86d) -fixed compilation warning: drivers/crypto/caam/caamrng.c:271:2: warning: format '%d' expects argument of type 'int', but argument 2 has type 'size_t' [-Wformat=] -changed commit headline Signed-off-by: Horia Geantă --- drivers/crypto/caam/Kconfig | 8 ++++++++ drivers/crypto/caam/caamrng.c | 47 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+) --- a/drivers/crypto/caam/Kconfig +++ b/drivers/crypto/caam/Kconfig @@ -148,6 +148,14 @@ config CRYPTO_DEV_FSL_CAAM_RNG_API Selecting this will register the SEC4 hardware rng to the hw_random API for suppying the kernel entropy pool. +config CRYPTO_DEV_FSL_CAAM_RNG_TEST + bool "Test caam rng" + depends on 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 --- a/drivers/crypto/caam/caamrng.c +++ b/drivers/crypto/caam/caamrng.c @@ -258,6 +258,49 @@ static void caam_cleanup(struct hwrng *r rng_unmap_ctx(rng_ctx); } +#ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_TEST +static inline void test_len(struct hwrng *rng, size_t len, bool wait) +{ + u8 *buf; + int real_len; + + buf = kzalloc(sizeof(u8) * len, GFP_KERNEL); + real_len = rng->read(rng, buf, len, wait); + if (real_len == 0 && wait) + pr_err("WAITING FAILED\n"); + pr_info("wanted %zu bytes, got %d\n", len, real_len); + print_hex_dump(KERN_INFO, "random bytes@: ", DUMP_PREFIX_ADDRESS, + 16, 4, buf, real_len, 1); + kfree(buf); +} + +static inline void test_mode_once(struct hwrng *rng, bool wait) +{ +#define TEST_CHUNK (RN_BUF_SIZE / 4) + + test_len(rng, TEST_CHUNK, wait); + test_len(rng, RN_BUF_SIZE * 2, wait); + test_len(rng, RN_BUF_SIZE * 2 - TEST_CHUNK, wait); +} + +static inline void test_mode(struct hwrng *rng, bool wait) +{ +#define TEST_PASS 1 + int i; + + for (i = 0; i < TEST_PASS; i++) + test_mode_once(rng, wait); +} + +static void self_test(struct hwrng *rng) +{ + pr_info("testing without waiting\n"); + test_mode(rng, false); + pr_info("testing with waiting\n"); + test_mode(rng, true); +} +#endif + static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id) { struct buf_data *bd = &ctx->bufs[buf_id]; @@ -342,6 +385,10 @@ int caam_rng_init(struct device *ctrldev if (err) goto free_rng_ctx; +#ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_TEST + self_test(&caam_rng); +#endif + dev_info(dev, "registering rng-caam\n"); err = hwrng_register(&caam_rng);