1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright(c) 2022 Intel Corporation. */
3 
4 #include <linux/bitfield.h>
5 #include <linux/module.h>
6 #include <linux/kdev_t.h>
7 #include <linux/semaphore.h>
8 #include <linux/slab.h>
9 
10 #include <asm/cpu_device_id.h>
11 
12 #include "ifs.h"
13 
14 #define X86_MATCH(model, array_gen)				\
15 	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6,	\
16 		INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, array_gen)
17 
18 static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
19 	X86_MATCH(SAPPHIRERAPIDS_X, ARRAY_GEN0),
20 	X86_MATCH(EMERALDRAPIDS_X, ARRAY_GEN0),
21 	X86_MATCH(GRANITERAPIDS_X, ARRAY_GEN0),
22 	X86_MATCH(GRANITERAPIDS_D, ARRAY_GEN0),
23 	X86_MATCH(ATOM_CRESTMONT_X, ARRAY_GEN1),
24 	{}
25 };
26 MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
27 
28 ATTRIBUTE_GROUPS(plat_ifs);
29 ATTRIBUTE_GROUPS(plat_ifs_array);
30 
31 bool *ifs_pkg_auth;
32 
33 static const struct ifs_test_caps scan_test = {
34 	.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
35 	.test_num = IFS_TYPE_SAF,
36 };
37 
38 static const struct ifs_test_caps array_test = {
39 	.integrity_cap_bit = MSR_INTEGRITY_CAPS_ARRAY_BIST_BIT,
40 	.test_num = IFS_TYPE_ARRAY_BIST,
41 };
42 
43 static struct ifs_device ifs_devices[] = {
44 	[IFS_TYPE_SAF] = {
45 		.test_caps = &scan_test,
46 		.misc = {
47 			.name = "intel_ifs_0",
48 			.minor = MISC_DYNAMIC_MINOR,
49 			.groups = plat_ifs_groups,
50 		},
51 	},
52 	[IFS_TYPE_ARRAY_BIST] = {
53 		.test_caps = &array_test,
54 		.misc = {
55 			.name = "intel_ifs_1",
56 			.minor = MISC_DYNAMIC_MINOR,
57 			.groups = plat_ifs_array_groups,
58 		},
59 	},
60 };
61 
62 #define IFS_NUMTESTS ARRAY_SIZE(ifs_devices)
63 
ifs_cleanup(void)64 static void ifs_cleanup(void)
65 {
66 	int i;
67 
68 	for (i = 0; i < IFS_NUMTESTS; i++) {
69 		if (ifs_devices[i].misc.this_device)
70 			misc_deregister(&ifs_devices[i].misc);
71 	}
72 	kfree(ifs_pkg_auth);
73 }
74 
ifs_init(void)75 static int __init ifs_init(void)
76 {
77 	const struct x86_cpu_id *m;
78 	u64 msrval;
79 	int i, ret;
80 
81 	m = x86_match_cpu(ifs_cpu_ids);
82 	if (!m)
83 		return -ENODEV;
84 
85 	if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &msrval))
86 		return -ENODEV;
87 
88 	if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS))
89 		return -ENODEV;
90 
91 	if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
92 		return -ENODEV;
93 
94 	ifs_pkg_auth = kmalloc_array(topology_max_packages(), sizeof(bool), GFP_KERNEL);
95 	if (!ifs_pkg_auth)
96 		return -ENOMEM;
97 
98 	for (i = 0; i < IFS_NUMTESTS; i++) {
99 		if (!(msrval & BIT(ifs_devices[i].test_caps->integrity_cap_bit)))
100 			continue;
101 		ifs_devices[i].rw_data.generation = FIELD_GET(MSR_INTEGRITY_CAPS_SAF_GEN_MASK,
102 							      msrval);
103 		ifs_devices[i].rw_data.array_gen = (u32)m->driver_data;
104 		ret = misc_register(&ifs_devices[i].misc);
105 		if (ret)
106 			goto err_exit;
107 	}
108 	return 0;
109 
110 err_exit:
111 	ifs_cleanup();
112 	return ret;
113 }
114 
ifs_exit(void)115 static void __exit ifs_exit(void)
116 {
117 	ifs_cleanup();
118 }
119 
120 module_init(ifs_init);
121 module_exit(ifs_exit);
122 
123 MODULE_LICENSE("GPL");
124 MODULE_DESCRIPTION("Intel In Field Scan (IFS) device");
125