2 files changed, 136 insertions, 0 deletions
diff --git a/sys/dev/random/armv8rng.c b/sys/dev/random/armv8rng.c
new file mode 100644
index 000000000000..3cca42a5bbf3
--- /dev/null
+++ b/sys/dev/random/armv8rng.c
@@ -0,0 +1,135 @@
+/*-
+ * Copyright (c) 2022 The FreeBSD Foundation
+ *
+ * This software was developed by Andrew Turner under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/conf.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/random.h>
+
+#include <machine/armreg.h>
+
+#include <dev/random/randomdev.h>
+
+static u_int random_rndr_read(void *, u_int);
+
+static bool has_rndr;
+static struct random_source random_armv8_rndr = {
+	.rs_ident = "Armv8 rndr RNG",
+	.rs_source = RANDOM_PURE_ARMV8,
+	.rs_read = random_rndr_read,
+};
+
+static inline int
+random_rndr_read_one(u_long *buf)
+{
+	u_long val;
+	int loop, ret;
+
+	loop = 10;
+	do {
+		__asm __volatile(
+		    ".arch_extension rng   \n"
+		    "mrs	%0, rndrrs \n" /* Read the random number */
+		    "cset	%w1, ne    \n" /* 1 on success, 0 on failure */
+		    ".arch_extension norng \n"
+		    : "=&r" (val), "=&r"(ret) :: "cc");
+	} while (ret != 0 && --loop > 0);
+
+	if (ret != 0)
+		*buf = val;
+
+	return (ret);
+}
+
+static u_int
+random_rndr_read(void *buf, u_int c)
+{
+	u_long *b;
+	u_int count;
+
+	b = buf;
+	for (count = 0; count < c; count += sizeof(*b)) {
+		if (!random_rndr_read_one(b))
+			break;
+
+		b++;
+	}
+
+	return (count);
+}
+
+static int
+rndr_modevent(module_t mod, int type, void *unused)
+{
+	uint64_t reg;
+	int error = 0;
+
+	switch (type) {
+	case MOD_LOAD:
+		has_rndr = false;
+		if (get_kernel_reg(ID_AA64ISAR0_EL1, &reg) &&
+		    ID_AA64ISAR0_RNDR_VAL(reg) != ID_AA64ISAR0_RNDR_NONE) {
+			has_rndr = true;
+			random_source_register(&random_armv8_rndr);
+			printf("random: fast provider: \"%s\"\n",
+			    random_armv8_rndr.rs_ident);
+		}
+		break;
+
+	case MOD_UNLOAD:
+		if (has_rndr)
+			random_source_deregister(&random_armv8_rndr);
+		break;
+
+	case MOD_SHUTDOWN:
+		break;
+
+	default:
+		error = EOPNOTSUPP;
+		break;
+
+	}
+
+	return (error);
+}
+
+static moduledata_t rndr_mod = {
+	"rndr",
+	rndr_modevent,
+	0
+};
+
+DECLARE_MODULE(rndr, rndr_mod, SI_SUB_RANDOM, SI_ORDER_FOURTH);
+MODULE_VERSION(rndr, 1);
+MODULE_DEPEND(rndr, random_harvestq, 1, 1, 1);
diff --git a/sys/dev/random/random_harvestq.c b/sys/dev/random/random_harvestq.c
index 09b81950281b..dce0878513db 100644
--- a/sys/dev/random/random_harvestq.c
+++ b/sys/dev/random/random_harvestq.c
@@ -385,6 +385,7 @@ static const char *random_source_descr[ENTROPYSOURCE] = {
 	[RANDOM_PURE_TPM] = "PURE_TPM",
 	[RANDOM_PURE_VMGENID] = "PURE_VMGENID",
 	[RANDOM_PURE_QUALCOMM] = "PURE_QUALCOMM",
+	[RANDOM_PURE_ARMV8] = "PURE_ARMV8",
 	/* "ENTROPYSOURCE" */
 };