1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2018 Andrew Turner 5 * 6 * This software was developed by SRI International and the University of 7 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237 8 * ("CTSRD"), as part of the DARPA CRASH research programme. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include "opt_acpi.h" 33 #include "opt_platform.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/bus.h> 38 #include <sys/kernel.h> 39 #include <sys/module.h> 40 41 #include <dev/psci/psci.h> 42 #include <dev/psci/smccc.h> 43 44 #define SMCCC_VERSION_1_0 0x10000 45 46 /* Assume 1.0 until we detect a later version */ 47 static uint32_t smccc_version; 48 49 void 50 smccc_init(void) 51 { 52 int32_t features; 53 uint32_t ret; 54 55 smccc_version = SMCCC_VERSION_1_0; 56 features = psci_features(SMCCC_VERSION); 57 if (features != PSCI_RETVAL_NOT_SUPPORTED) { 58 ret = psci_call(SMCCC_VERSION, 0, 0, 0); 59 /* This should always be the case as we checked it above */ 60 if (ret > 0) 61 smccc_version = ret; 62 } 63 64 if (bootverbose) { 65 printf("Found SMCCC version %u.%u\n", 66 SMCCC_VERSION_MAJOR(smccc_version), 67 SMCCC_VERSION_MINOR(smccc_version)); 68 } 69 } 70 71 static int 72 smccc_probe(device_t dev) 73 { 74 int32_t version; 75 76 /* 77 * If the version is not implemented then we treat it as SMCCC 1.0 78 */ 79 if (psci_features(SMCCC_VERSION) == PSCI_RETVAL_NOT_SUPPORTED || 80 (version = arm_smccc_invoke(SMCCC_VERSION, NULL)) <= 0) { 81 device_set_desc(dev, "ARM SMCCC v1.0"); 82 return (0); 83 } 84 85 device_set_descf(dev, "ARM SMCCC v%d.%d", SMCCC_VERSION_MAJOR(version), 86 SMCCC_VERSION_MINOR(version)); 87 88 return (0); 89 } 90 91 static int 92 smccc_attach(device_t dev) 93 { 94 bus_attach_children(dev); 95 return (0); 96 } 97 98 uint32_t 99 smccc_get_version(void) 100 { 101 MPASS(smccc_version != 0); 102 return (smccc_version); 103 } 104 105 int32_t 106 smccc_arch_features(uint32_t smccc_func_id) 107 { 108 109 MPASS(smccc_version != 0); 110 if (smccc_version == SMCCC_VERSION_1_0) 111 return (PSCI_RETVAL_NOT_SUPPORTED); 112 113 return (arm_smccc_invoke(SMCCC_ARCH_FEATURES, smccc_func_id, NULL)); 114 } 115 116 /* 117 * The SMCCC handler for Spectre variant 2: Branch target injection. 118 * (CVE-2017-5715) 119 */ 120 int 121 smccc_arch_workaround_1(void) 122 { 123 124 MPASS(smccc_version != 0); 125 KASSERT(smccc_version != SMCCC_VERSION_1_0, 126 ("SMCCC arch workaround 1 called with an invalid SMCCC interface")); 127 return (arm_smccc_invoke(SMCCC_ARCH_WORKAROUND_1, NULL)); 128 } 129 130 int 131 smccc_arch_workaround_2(int enable) 132 { 133 134 MPASS(smccc_version != 0); 135 KASSERT(smccc_version != SMCCC_VERSION_1_0, 136 ("SMCCC arch workaround 2 called with an invalid SMCCC interface")); 137 return (arm_smccc_invoke(SMCCC_ARCH_WORKAROUND_2, enable, NULL)); 138 } 139 140 static device_method_t smccc_methods[] = { 141 DEVMETHOD(device_probe, smccc_probe), 142 DEVMETHOD(device_attach, smccc_attach), 143 144 DEVMETHOD(bus_add_child, bus_generic_add_child), 145 146 DEVMETHOD_END 147 }; 148 149 static driver_t smccc_driver = { 150 "smccc", 151 smccc_methods, 152 0, 153 }; 154 155 EARLY_DRIVER_MODULE(smccc, psci, smccc_driver, 0, 0, 156 BUS_PASS_CPU + BUS_PASS_ORDER_FIRST); 157