diff --git a/sys/conf/files.arm64 b/sys/conf/files.arm64 --- a/sys/conf/files.arm64 +++ b/sys/conf/files.arm64 @@ -418,6 +418,7 @@ dev/psci/psci.c standard dev/psci/smccc_arm64.S standard +dev/psci/smccc_trng.c standard dev/psci/smccc.c standard dev/pwm/controller/allwinner/aw_pwm.c optional fdt aw_pwm diff --git a/sys/dev/psci/smccc_trng.c b/sys/dev/psci/smccc_trng.c new file mode 100644 --- /dev/null +++ b/sys/dev/psci/smccc_trng.c @@ -0,0 +1,140 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2024 Arm Ltd + * + * 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. + */ + +/* + * A driver for the Arm True Random Number Generator Firmware Interface. + * This queries into the SMCCC firmware for random numbers using the + * interface documented in den0098 [1]. + * + * [1] https://developer.arm.com/documentation/den0098/latest + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include + +#define TRNG_VERSION SMCCC_FUNC_ID(SMCCC_FAST_CALL, \ + SMCCC_32BIT_CALL, SMCCC_STD_SECURE_SERVICE_CALLS, 0x50) +#define TRNG_VERSION_MIN 0x10000L +#define TRNG_RND64 SMCCC_FUNC_ID(SMCCC_FAST_CALL, \ + SMCCC_64BIT_CALL, SMCCC_STD_SECURE_SERVICE_CALLS, 0x53) + +static device_identify_t trng_identify; +static device_probe_t trng_probe; +static device_attach_t trng_attach; + +static unsigned trng_read(void *, unsigned); + +static struct random_source random_trng = { + .rs_ident = "Arm SMCCC TRNG", + .rs_source = RANDOM_PURE_ARM_TRNG, + .rs_read = trng_read, +}; + +static void +trng_identify(driver_t *driver, device_t parent) +{ + int32_t version; + + /* Check we have TRNG 1.0 or later */ + version = psci_call(TRNG_VERSION, 0, 0, 0); + if (version < TRNG_VERSION_MIN) + return; + + if (BUS_ADD_CHILD(parent, 0, "trng", -1) == NULL) + device_printf(parent, "add TRNG child failed\n"); +} + +static int +trng_probe(device_t dev) +{ + device_set_desc(dev, "Arm SMCCC TRNG"); + return (BUS_PROBE_NOWILDCARD); +} + +static int +trng_attach(device_t dev) +{ + struct arm_smccc_res res; + struct trng_softc *sc; + int32_t ret; + + ret = arm_smccc_invoke(TRNG_RND64, 192, &res); + if (ret < 0) { + device_printf(dev, "Failed to read fron TRNG\n"); + } else { + random_source_register(&random_trng); + } + + return (0); +} + +static unsigned +trng_read(void *buf, unsigned usz) +{ + struct arm_smccc_res res; + register_t len; + int32_t ret; + + len = usz; + if (len > sizeof(uint64_t)) + len = sizeof(uint64_t); + if (len == 0) + return (0); + + ret = psci_callfn(TRNG_RND64, len * 8, 0, 0, 0, 0, 0, 0, &res); + if (ret < 0) + return (0); + + memcpy(buf, &res.a0, len); + return (len); +} + +static device_method_t trng_methods[] = { + DEVMETHOD(device_identify, trng_identify), + DEVMETHOD(device_probe, trng_probe), + DEVMETHOD(device_attach, trng_attach), + + DEVMETHOD_END +}; + +static driver_t trng_driver = { + "trng", + trng_methods, + 0 +}; + +DRIVER_MODULE(trng, smccc, trng_driver, 0, 0); diff --git a/sys/dev/random/random_harvestq.c b/sys/dev/random/random_harvestq.c --- a/sys/dev/random/random_harvestq.c +++ b/sys/dev/random/random_harvestq.c @@ -386,6 +386,7 @@ [RANDOM_PURE_VMGENID] = "PURE_VMGENID", [RANDOM_PURE_QUALCOMM] = "PURE_QUALCOMM", [RANDOM_PURE_ARMV8] = "PURE_ARMV8", + [RANDOM_PURE_ARM_TRNG] = "PURE_ARM_TRNG", /* "ENTROPYSOURCE" */ }; diff --git a/sys/sys/random.h b/sys/sys/random.h --- a/sys/sys/random.h +++ b/sys/sys/random.h @@ -103,6 +103,7 @@ RANDOM_PURE_VMGENID, RANDOM_PURE_QUALCOMM, RANDOM_PURE_ARMV8, + RANDOM_PURE_ARM_TRNG, ENTROPYSOURCE }; _Static_assert(ENTROPYSOURCE <= 32,