xref: /openbmc/linux/drivers/firmware/smccc/smccc.c (revision 35727af2)
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 
15 static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
16 static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
17 
18 bool __ro_after_init smccc_trng_available = false;
19 u64 __ro_after_init smccc_has_sve_hint = false;
20 s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
21 s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
22 
arm_smccc_version_init(u32 version,enum arm_smccc_conduit conduit)23 void __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 
arm_smccc_1_1_get_conduit(void)48 enum 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 }
55 EXPORT_SYMBOL_GPL(arm_smccc_1_1_get_conduit);
56 
arm_smccc_get_version(void)57 u32 arm_smccc_get_version(void)
58 {
59 	return smccc_version;
60 }
61 EXPORT_SYMBOL_GPL(arm_smccc_get_version);
62 
arm_smccc_get_soc_id_version(void)63 s32 arm_smccc_get_soc_id_version(void)
64 {
65 	return smccc_soc_id_version;
66 }
67 
arm_smccc_get_soc_id_revision(void)68 s32 arm_smccc_get_soc_id_revision(void)
69 {
70 	return smccc_soc_id_revision;
71 }
72 
smccc_devices_init(void)73 static int __init smccc_devices_init(void)
74 {
75 	struct platform_device *pdev;
76 
77 	if (smccc_trng_available) {
78 		pdev = platform_device_register_simple("smccc_trng", -1,
79 						       NULL, 0);
80 		if (IS_ERR(pdev))
81 			pr_err("smccc_trng: could not register device: %ld\n",
82 			       PTR_ERR(pdev));
83 	}
84 
85 	return 0;
86 }
87 device_initcall(smccc_devices_init);
88