cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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soc_id.c (3020B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright 2020 Arm Limited
      4 */
      5
      6#define pr_fmt(fmt) "SMCCC: SOC_ID: " fmt
      7
      8#include <linux/arm-smccc.h>
      9#include <linux/bitfield.h>
     10#include <linux/device.h>
     11#include <linux/module.h>
     12#include <linux/kernel.h>
     13#include <linux/slab.h>
     14#include <linux/sys_soc.h>
     15
     16#define SMCCC_SOC_ID_JEP106_BANK_IDX_MASK	GENMASK(30, 24)
     17/*
     18 * As per the SMC Calling Convention specification v1.2 (ARM DEN 0028C)
     19 * Section 7.4 SMCCC_ARCH_SOC_ID bits[23:16] are JEP-106 identification
     20 * code with parity bit for the SiP. We can drop the parity bit.
     21 */
     22#define SMCCC_SOC_ID_JEP106_ID_CODE_MASK	GENMASK(22, 16)
     23#define SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK	GENMASK(15, 0)
     24
     25#define JEP106_BANK_CONT_CODE(x)	\
     26	(u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_BANK_IDX_MASK, (x)))
     27#define JEP106_ID_CODE(x)	\
     28	(u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_ID_CODE_MASK, (x)))
     29#define IMP_DEF_SOC_ID(x)	\
     30	(u16)(FIELD_GET(SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK, (x)))
     31
     32static struct soc_device *soc_dev;
     33static struct soc_device_attribute *soc_dev_attr;
     34
     35static int __init smccc_soc_init(void)
     36{
     37	struct arm_smccc_res res;
     38	int soc_id_rev, soc_id_version;
     39	static char soc_id_str[20], soc_id_rev_str[12];
     40	static char soc_id_jep106_id_str[12];
     41
     42	if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
     43		return 0;
     44
     45	if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE) {
     46		pr_err("%s: invalid SMCCC conduit\n", __func__);
     47		return -EOPNOTSUPP;
     48	}
     49
     50	arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
     51			     ARM_SMCCC_ARCH_SOC_ID, &res);
     52
     53	if ((int)res.a0 == SMCCC_RET_NOT_SUPPORTED) {
     54		pr_info("ARCH_SOC_ID not implemented, skipping ....\n");
     55		return 0;
     56	}
     57
     58	if ((int)res.a0 < 0) {
     59		pr_info("ARCH_FEATURES(ARCH_SOC_ID) returned error: %lx\n",
     60			res.a0);
     61		return -EINVAL;
     62	}
     63
     64	arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res);
     65	if ((int)res.a0 < 0) {
     66		pr_err("ARCH_SOC_ID(0) returned error: %lx\n", res.a0);
     67		return -EINVAL;
     68	}
     69
     70	soc_id_version = res.a0;
     71
     72	arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res);
     73	if ((int)res.a0 < 0) {
     74		pr_err("ARCH_SOC_ID(1) returned error: %lx\n", res.a0);
     75		return -EINVAL;
     76	}
     77
     78	soc_id_rev = res.a0;
     79
     80	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
     81	if (!soc_dev_attr)
     82		return -ENOMEM;
     83
     84	sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
     85	sprintf(soc_id_jep106_id_str, "jep106:%02x%02x",
     86		JEP106_BANK_CONT_CODE(soc_id_version),
     87		JEP106_ID_CODE(soc_id_version));
     88	sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str,
     89		IMP_DEF_SOC_ID(soc_id_version));
     90
     91	soc_dev_attr->soc_id = soc_id_str;
     92	soc_dev_attr->revision = soc_id_rev_str;
     93	soc_dev_attr->family = soc_id_jep106_id_str;
     94
     95	soc_dev = soc_device_register(soc_dev_attr);
     96	if (IS_ERR(soc_dev)) {
     97		kfree(soc_dev_attr);
     98		return PTR_ERR(soc_dev);
     99	}
    100
    101	pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id,
    102		soc_dev_attr->revision);
    103
    104	return 0;
    105}
    106module_init(smccc_soc_init);
    107
    108static void __exit smccc_soc_exit(void)
    109{
    110	if (soc_dev)
    111		soc_device_unregister(soc_dev);
    112	kfree(soc_dev_attr);
    113}
    114module_exit(smccc_soc_exit);