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#include <linux/slab.h>
 8
 9#include <asm/cpu_device_id.h>
10
11#include "ifs.h"
12
13#define X86_MATCH(model)				\
14	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6,	\
15		INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL)
16
17static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
18	X86_MATCH(SAPPHIRERAPIDS_X),
19	{}
20};
21MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
22
23static struct ifs_device ifs_device = {
24	.data = {
25		.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
26		.test_num = 0,
27	},
28	.misc = {
29		.name = "intel_ifs_0",
30		.nodename = "intel_ifs/0",
31		.minor = MISC_DYNAMIC_MINOR,
32	},
33};
34
35static int __init ifs_init(void)
36{
37	const struct x86_cpu_id *m;
38	u64 msrval;
39	int ret;
40
41	m = x86_match_cpu(ifs_cpu_ids);
42	if (!m)
43		return -ENODEV;
44
45	if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &msrval))
46		return -ENODEV;
47
48	if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS))
49		return -ENODEV;
50
51	if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
52		return -ENODEV;
53
54	ifs_device.misc.groups = ifs_get_groups();
55
56	if (!(msrval & BIT(ifs_device.data.integrity_cap_bit)))
57		return -ENODEV;
58
59	ifs_device.data.pkg_auth = kmalloc_array(topology_max_packages(), sizeof(bool), GFP_KERNEL);
60	if (!ifs_device.data.pkg_auth)
61		return -ENOMEM;
62
63	ret = misc_register(&ifs_device.misc);
64	if (ret) {
65		kfree(ifs_device.data.pkg_auth);
66		return ret;
67	}
68
69	return 0;
70}
71
72static void __exit ifs_exit(void)
73{
74	misc_deregister(&ifs_device.misc);
75	kfree(ifs_device.data.pkg_auth);
76}
77
78module_init(ifs_init);
79module_exit(ifs_exit);
80
81MODULE_LICENSE("GPL");
82MODULE_DESCRIPTION("Intel In Field Scan (IFS) device");