From 6dc019ca785d8802e17463283c7a6ca7907054c3 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 Add a test for the Freescale CAAM Random Number Generator 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 --- drivers/crypto/caam/Kconfig | 10 ++++++++ drivers/crypto/caam/caamrng.c | 47 +++++++++++++++++++++++++++++++++++ 2 files changed, 57 insertions(+) diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig index 64bf3024b680..83c1bb8ca8e2 100644 --- a/drivers/crypto/caam/Kconfig +++ b/drivers/crypto/caam/Kconfig @@ -128,6 +128,16 @@ config CRYPTO_DEV_FSL_CAAM_IMX def_bool SOC_IMX6 || SOC_IMX7D depends on CRYPTO_DEV_FSL_CAAM + +config CRYPTO_DEV_FSL_CAAM_RNG_TEST + boolean "Test caam rng" + depends on CRYPTO_DEV_FSL_CAAM_RNG_API + default n + 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. + config CRYPTO_DEV_FSL_CAAM_DEBUG bool "Enable debug output in CAAM driver" depends on CRYPTO_DEV_FSL_CAAM diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c index 9b92af2c7241..601381c239d8 100644 --- a/drivers/crypto/caam/caamrng.c +++ b/drivers/crypto/caam/caamrng.c @@ -256,6 +256,49 @@ static void caam_cleanup(struct hwrng *rng) 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 %d 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]; @@ -360,6 +403,10 @@ static int __init caam_rng_init(void) 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"); return hwrng_register(&caam_rng); -- 2.17.1