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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core.c (1523B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/* Copyright(c) 2022 Intel Corporation. */
      3
      4#include <linux/module.h>
      5#include <linux/kdev_t.h>
      6#include <linux/semaphore.h>
      7
      8#include <asm/cpu_device_id.h>
      9
     10#include "ifs.h"
     11
     12#define X86_MATCH(model)				\
     13	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6,	\
     14		INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL)
     15
     16static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
     17	X86_MATCH(SAPPHIRERAPIDS_X),
     18	{}
     19};
     20MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
     21
     22static struct ifs_device ifs_device = {
     23	.data = {
     24		.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
     25	},
     26	.misc = {
     27		.name = "intel_ifs_0",
     28		.nodename = "intel_ifs/0",
     29		.minor = MISC_DYNAMIC_MINOR,
     30	},
     31};
     32
     33static int __init ifs_init(void)
     34{
     35	const struct x86_cpu_id *m;
     36	u64 msrval;
     37
     38	m = x86_match_cpu(ifs_cpu_ids);
     39	if (!m)
     40		return -ENODEV;
     41
     42	if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &msrval))
     43		return -ENODEV;
     44
     45	if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS))
     46		return -ENODEV;
     47
     48	if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
     49		return -ENODEV;
     50
     51	ifs_device.misc.groups = ifs_get_groups();
     52
     53	if ((msrval & BIT(ifs_device.data.integrity_cap_bit)) &&
     54	    !misc_register(&ifs_device.misc)) {
     55		down(&ifs_sem);
     56		ifs_load_firmware(ifs_device.misc.this_device);
     57		up(&ifs_sem);
     58		return 0;
     59	}
     60
     61	return -ENODEV;
     62}
     63
     64static void __exit ifs_exit(void)
     65{
     66	misc_deregister(&ifs_device.misc);
     67}
     68
     69module_init(ifs_init);
     70module_exit(ifs_exit);
     71
     72MODULE_LICENSE("GPL");
     73MODULE_DESCRIPTION("Intel In Field Scan (IFS) device");