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
smccc_init(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
smccc_probe(device_t dev)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
smccc_attach(device_t dev)92 smccc_attach(device_t dev)
93 {
94 bus_attach_children(dev);
95 return (0);
96 }
97
98 uint32_t
smccc_get_version(void)99 smccc_get_version(void)
100 {
101 MPASS(smccc_version != 0);
102 return (smccc_version);
103 }
104
105 int32_t
smccc_arch_features(uint32_t smccc_func_id)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
smccc_arch_workaround_1(void)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
smccc_arch_workaround_2(int enable)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