smccc.c

   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
  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
  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
  57 u32 arm_smccc_get_version(void)
  58 {
  59         return smccc_version;
  60 }
  61 EXPORT_SYMBOL_GPL(arm_smccc_get_version);
  62
  63 s32 arm_smccc_get_soc_id_version(void)
  64 {
  65         return smccc_soc_id_version;
  66 }
  67
  68 s32 arm_smccc_get_soc_id_revision(void)
  69 {
  70         return smccc_soc_id_revision;
  71 }
  72
  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);