From: "Victoria Milhoan (b42089)" <vicki.milhoan@xxxxxxxxxxxxx>
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 <vicki.milhoan@xxxxxxxxxxxxx>
Signed-off-by: Dan Douglass <dan.douglass@xxxxxxx>
Signed-off-by: Vipul Kumar <vipul_kumar@xxxxxxxxxx>
Signed-off-by: Horia Geantă <horia.geanta@xxxxxxx>
Signed-off-by: Meenakshi Aggarwal <meenakshi.aggarwal@xxxxxxx>
---
drivers/crypto/caam/Kconfig | 9 +++++++
drivers/crypto/caam/caamrng.c | 48 +++++++++++++++++++++++++++++++++++
2 files changed, 57 insertions(+)
diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig
index ec6a9e6ad4d2..c631f99e415f 100644
--- a/drivers/crypto/caam/Kconfig
+++ b/drivers/crypto/caam/Kconfig
@@ -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
diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
index 50eb55da45c2..b3d14a7f4dd1 100644
--- a/drivers/crypto/caam/caamrng.c
+++ b/drivers/crypto/caam/caamrng.c
@@ -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;
}
--
2.25.1
