Openwrt/target/linux/layerscape/patches-5.4/804-crypto-0014-MLK-9769-8-crypto-caam-add-a-test-for-the-RNG.patch

From 387a26c56933fbfd0fa211ad5347d48d08695ea0 Mon Sep 17 00:00:00 2001
From: "Victoria Milhoan (b42089)" <vicki.milhoan@freescale.com>
Date: Fri, 17 Oct 2014 16:30:56 -0700
Subject: [PATCH] MLK-9769-8 crypto: caam - add a test for the RNG
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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 <vicki.milhoan@freescale.com>
Signed-off-by: Dan Douglass <dan.douglass@freescale.com>
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
(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 <horia.geanta@nxp.com>
---
 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
@@ -147,6 +147,14 @@ 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);