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android-kvm / linux / 10f865cdcf37d26ae5e9595a7b4f9e06538e84e5 / . / arch / powerpc / platforms / powernv / opal-secvar.c
blob: 14133e120bdd26896dbc514cf94fbf706733c020 [file] [log] [blame]
Nayna Jain9155e232019-11-10 21:10:33 -0600[diff] [blame]1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PowerNV code for secure variables
4 *
5 * Copyright (C) 2019 IBM Corporation
6 * Author: Claudio Carvalho
7 * Nayna Jain
8 *
9 * APIs to access secure variables managed by OPAL.
10 */
11
12#define pr_fmt(fmt) "secvar: "fmt
13
14#include <linux/types.h>
15#include <linux/platform_device.h>
16#include <linux/of_platform.h>
17#include <asm/opal.h>
18#include <asm/secvar.h>
19#include <asm/secure_boot.h>
20
21static int opal_status_to_err(int rc)
22{
23 int err;
24
25 switch (rc) {
26 case OPAL_SUCCESS:
27 err = 0;
28 break;
29 case OPAL_UNSUPPORTED:
30 err = -ENXIO;
31 break;
32 case OPAL_PARAMETER:
33 err = -EINVAL;
34 break;
35 case OPAL_RESOURCE:
36 err = -ENOSPC;
37 break;
38 case OPAL_HARDWARE:
39 err = -EIO;
40 break;
41 case OPAL_NO_MEM:
42 err = -ENOMEM;
43 break;
44 case OPAL_EMPTY:
45 err = -ENOENT;
46 break;
47 case OPAL_PARTIAL:
48 err = -EFBIG;
49 break;
50 default:
51 err = -EINVAL;
52 }
53
54 return err;
55}
56
57static int opal_get_variable(const char *key, uint64_t ksize,
58 u8 *data, uint64_t *dsize)
59{
60 int rc;
61
62 if (!key || !dsize)
63 return -EINVAL;
64
65 *dsize = cpu_to_be64(*dsize);
66
67 rc = opal_secvar_get(key, ksize, data, dsize);
68
69 *dsize = be64_to_cpu(*dsize);
70
71 return opal_status_to_err(rc);
72}
73
74static int opal_get_next_variable(const char *key, uint64_t *keylen,
75 uint64_t keybufsize)
76{
77 int rc;
78
79 if (!key || !keylen)
80 return -EINVAL;
81
82 *keylen = cpu_to_be64(*keylen);
83
84 rc = opal_secvar_get_next(key, keylen, keybufsize);
85
86 *keylen = be64_to_cpu(*keylen);
87
88 return opal_status_to_err(rc);
89}
90
91static int opal_set_variable(const char *key, uint64_t ksize, u8 *data,
92 uint64_t dsize)
93{
94 int rc;
95
96 if (!key || !data)
97 return -EINVAL;
98
99 rc = opal_secvar_enqueue_update(key, ksize, data, dsize);
100
101 return opal_status_to_err(rc);
102}
103
104static const struct secvar_operations opal_secvar_ops = {
105 .get = opal_get_variable,
106 .get_next = opal_get_next_variable,
107 .set = opal_set_variable,
108};
109
110static int opal_secvar_probe(struct platform_device *pdev)
111{
112 if (!opal_check_token(OPAL_SECVAR_GET)
113 || !opal_check_token(OPAL_SECVAR_GET_NEXT)
114 || !opal_check_token(OPAL_SECVAR_ENQUEUE_UPDATE)) {
115 pr_err("OPAL doesn't support secure variables\n");
116 return -ENODEV;
117 }
118
119 set_secvar_ops(&opal_secvar_ops);
120
121 return 0;
122}
123
124static const struct of_device_id opal_secvar_match[] = {
125 { .compatible = "ibm,secvar-backend",},
126 {},
127};
128
129static struct platform_driver opal_secvar_driver = {
130 .driver = {
131 .name = "secvar",
132 .of_match_table = opal_secvar_match,
133 },
134};
135
136static int __init opal_secvar_init(void)
137{
138 return platform_driver_probe(&opal_secvar_driver, opal_secvar_probe);
139}
140device_initcall(opal_secvar_init);