tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2020 Arm Limited
4 */
5
6#define pr_fmt(fmt) "smccc: " fmt
7
8#include <linux/cache.h>
9#include <linux/init.h>
10#include <linux/arm-smccc.h>
11#include <linux/kernel.h>
12#include <linux/platform_device.h>
13#include <asm/archrandom.h>
14
15static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
16static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
17
18bool __ro_after_init smccc_trng_available = false;
19s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
20s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
21
22void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
23{
24 struct arm_smccc_res res;
25
26 smccc_version = version;
27 smccc_conduit = conduit;
28
29 smccc_trng_available = smccc_probe_trng();
30
31 if ((smccc_version >= ARM_SMCCC_VERSION_1_2) &&
32 (smccc_conduit != SMCCC_CONDUIT_NONE)) {
33 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
34 ARM_SMCCC_ARCH_SOC_ID, &res);
35 if ((s32)res.a0 >= 0) {
36 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res);
37 smccc_soc_id_version = (s32)res.a0;
38 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res);
39 smccc_soc_id_revision = (s32)res.a0;
40 }
41 }
42}
43
44enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
45{
46 if (smccc_version < ARM_SMCCC_VERSION_1_1)
47 return SMCCC_CONDUIT_NONE;
48
49 return smccc_conduit;
50}
51EXPORT_SYMBOL_GPL(arm_smccc_1_1_get_conduit);
52
53u32 arm_smccc_get_version(void)
54{
55 return smccc_version;
56}
57EXPORT_SYMBOL_GPL(arm_smccc_get_version);
58
59s32 arm_smccc_get_soc_id_version(void)
60{
61 return smccc_soc_id_version;
62}
63
64s32 arm_smccc_get_soc_id_revision(void)
65{
66 return smccc_soc_id_revision;
67}
68EXPORT_SYMBOL_GPL(arm_smccc_get_soc_id_revision);
69
70bool arm_smccc_hypervisor_has_uuid(const uuid_t *hyp_uuid)
71{
72 struct arm_smccc_res res = {};
73 uuid_t uuid;
74
75 if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
76 return false;
77
78 arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
79 if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
80 return false;
81
82 uuid = smccc_res_to_uuid(res.a0, res.a1, res.a2, res.a3);
83 return uuid_equal(&uuid, hyp_uuid);
84}
85EXPORT_SYMBOL_GPL(arm_smccc_hypervisor_has_uuid);
86
87static int __init smccc_devices_init(void)
88{
89 struct platform_device *pdev;
90
91 if (smccc_trng_available) {
92 pdev = platform_device_register_simple("smccc_trng", -1,
93 NULL, 0);
94 if (IS_ERR(pdev))
95 pr_err("smccc_trng: could not register device: %ld\n",
96 PTR_ERR(pdev));
97 }
98
99 return 0;
100}
101device_initcall(smccc_devices_init);