freebsd-dev/sys/dev/psci/smccc.c
Andrew Turner f651b52527 Add support for the ARM SMC Calling Convention (SMCCC). This is a method
to call into the firmware in a similar way to the existing PSCI, and used
PSCI to detect when SMCCC is enabled.

There is a function ID space we can use. Currently we only support 3
functions in the ARM Architecture Calls region, however it is expected we
will expend these in the future.

Sponsored by:	DARPA, AFRL
2018-06-13 15:32:00 +00:00

94 lines
2.9 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2018 Andrew Turner
*
* This software was developed by SRI International and the University of
* Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
* ("CTSRD"), as part of the DARPA CRASH research programme.
*
* 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 "opt_acpi.h"
#include "opt_platform.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <dev/psci/psci.h>
#include <dev/psci/smccc.h>
#define SMCCC_VERSION_1_0 0x10000
/* Assume 1.0 until we detect a later version */
static uint32_t smccc_version = SMCCC_VERSION_1_0;
static void
smccc_init(void *dummy)
{
int32_t features;
uint32_t ret;
features = psci_features(SMCCC_VERSION);
if (features != PSCI_RETVAL_NOT_SUPPORTED) {
ret = psci_call(SMCCC_VERSION, 0, 0, 0);
/* This should always be the case as we checked it above */
if (ret > 0)
smccc_version = ret;
}
if (bootverbose) {
printf("Found SMCCC version %u.%u\n",
SMCCC_VERSION_MAJOR(smccc_version),
SMCCC_VERSION_MINOR(smccc_version));
}
}
SYSINIT(smccc_start, SI_SUB_DRIVERS, SI_ORDER_ANY, smccc_init, NULL);
int32_t
smccc_arch_features(uint32_t smccc_func_id)
{
if (smccc_version == SMCCC_VERSION_1_0)
return (PSCI_RETVAL_NOT_SUPPORTED);
return (psci_call(SMCCC_ARCH_FEATURES, smccc_func_id, 0, 0));
}
/*
* The SMCCC handler for Spectre variant 2: Branch target injection.
* (CVE-2017-5715)
*/
int
smccc_arch_workaround_1(void)
{
KASSERT(smccc_version != SMCCC_VERSION_1_0,
("SMCCC arch workaround 1 called with an invalid SMCCC interface"));
return (psci_call(SMCCC_ARCH_WORKAROUND_1, 0, 0, 0));
}