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
16 static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
17 X86_MATCH(SAPPHIRERAPIDS_X),
18 {}
19 };
20 MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
21
22 static 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
ifs_init(void)33 static 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
ifs_exit(void)64 static void __exit ifs_exit(void)
65 {
66 misc_deregister(&ifs_device.misc);
67 }
68
69 module_init(ifs_init);
70 module_exit(ifs_exit);
71
72 MODULE_LICENSE("GPL");
73 MODULE_DESCRIPTION("Intel In Field Scan (IFS) device");
74