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;
19u64 __ro_after_init smccc_has_sve_hint = false;
20s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
21s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
22
23void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
24{
25 struct arm_smccc_res res;
26
27 smccc_version = version;
28 smccc_conduit = conduit;
29
30 smccc_trng_available = smccc_probe_trng();
31 if (IS_ENABLED(CONFIG_ARM64_SVE) &&
32 smccc_version >= ARM_SMCCC_VERSION_1_3)
33 smccc_has_sve_hint = true;
34
35 if ((smccc_version >= ARM_SMCCC_VERSION_1_2) &&
36 (smccc_conduit != SMCCC_CONDUIT_NONE)) {
37 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
38 ARM_SMCCC_ARCH_SOC_ID, &res);
39 if ((s32)res.a0 >= 0) {
40 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res);
41 smccc_soc_id_version = (s32)res.a0;
42 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res);
43 smccc_soc_id_revision = (s32)res.a0;
44 }
45 }
46}
47
48enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
49{
50 if (smccc_version < ARM_SMCCC_VERSION_1_1)
51 return SMCCC_CONDUIT_NONE;
52
53 return smccc_conduit;
54}
55EXPORT_SYMBOL_GPL(arm_smccc_1_1_get_conduit);
56
57u32 arm_smccc_get_version(void)
58{
59 return smccc_version;
60}
61EXPORT_SYMBOL_GPL(arm_smccc_get_version);
62
63s32 arm_smccc_get_soc_id_version(void)
64{
65 return smccc_soc_id_version;
66}
67
68s32 arm_smccc_get_soc_id_revision(void)
69{
70 return smccc_soc_id_revision;
71}
72
73static int __init smccc_devices_init(void)
74{
75 struct platform_device *pdev;
76
77 if (smccc_trng_available) {
78 pdev = platform_device_register_simple(name: "smccc_trng", id: -1,
79 NULL, num: 0);
80 if (IS_ERR(ptr: pdev))
81 pr_err("smccc_trng: could not register device: %ld\n",
82 PTR_ERR(pdev));
83 }
84
85 return 0;
86}
87device_initcall(smccc_devices_init);
88

source code of linux/drivers/firmware/smccc/smccc.c