FreeBSD/Linux Kernel Cross Reference
sys/dev/psci/smccc.c
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/cdefs.h>
36 __FBSDID("$FreeBSD$");
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41
42 #include <dev/psci/psci.h>
43 #include <dev/psci/smccc.h>
44
45 #define SMCCC_VERSION_1_0 0x10000
46
47 /* Assume 1.0 until we detect a later version */
48 static uint32_t smccc_version = SMCCC_VERSION_1_0;
49
50 static void
51 smccc_init(void *dummy)
52 {
53 int32_t features;
54 uint32_t ret;
55
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 SYSINIT(smccc_start, SI_SUB_CONFIGURE, SI_ORDER_ANY, smccc_init, NULL);
71
72 int32_t
73 smccc_arch_features(uint32_t smccc_func_id)
74 {
75
76 if (smccc_version == SMCCC_VERSION_1_0)
77 return (PSCI_RETVAL_NOT_SUPPORTED);
78
79 return (psci_call(SMCCC_ARCH_FEATURES, smccc_func_id, 0, 0));
80 }
81
82 /*
83 * The SMCCC handler for Spectre variant 2: Branch target injection.
84 * (CVE-2017-5715)
85 */
86 int
87 smccc_arch_workaround_1(void)
88 {
89
90 KASSERT(smccc_version != SMCCC_VERSION_1_0,
91 ("SMCCC arch workaround 1 called with an invalid SMCCC interface"));
92 return (psci_call(SMCCC_ARCH_WORKAROUND_1, 0, 0, 0));
93 }
94
95 int
96 smccc_arch_workaround_2(int enable)
97 {
98
99 KASSERT(smccc_version != SMCCC_VERSION_1_0,
100 ("SMCCC arch workaround 2 called with an invalid SMCCC interface"));
101 return (psci_call(SMCCC_ARCH_WORKAROUND_2, enable, 0, 0));
102 }
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