xref: /linux/drivers/platform/x86/intel/ifs/core.c (revision ab93e0dd72c37d378dd936f031ffb83ff2bd87ce)
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 #include <asm/msr.h>
12 
13 #include "ifs.h"
14 
15 #define X86_MATCH(vfm, array_gen)				\
16 	X86_MATCH_VFM_FEATURE(vfm, X86_FEATURE_CORE_CAPABILITIES, array_gen)
17 
18 static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
19 	X86_MATCH(INTEL_SAPPHIRERAPIDS_X, ARRAY_GEN0),
20 	X86_MATCH(INTEL_EMERALDRAPIDS_X, ARRAY_GEN0),
21 	X86_MATCH(INTEL_GRANITERAPIDS_X, ARRAY_GEN0),
22 	X86_MATCH(INTEL_GRANITERAPIDS_D, ARRAY_GEN0),
23 	X86_MATCH(INTEL_ATOM_CRESTMONT_X, ARRAY_GEN1),
24 	X86_MATCH(INTEL_ATOM_DARKMONT_X, ARRAY_GEN1),
25 	{}
26 };
27 MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
28 
29 ATTRIBUTE_GROUPS(plat_ifs);
30 ATTRIBUTE_GROUPS(plat_ifs_array);
31 
32 bool *ifs_pkg_auth;
33 
34 static const struct ifs_test_caps scan_test = {
35 	.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
36 	.test_num = IFS_TYPE_SAF,
37 	.image_suffix = "scan",
38 };
39 
40 static const struct ifs_test_caps array_test = {
41 	.integrity_cap_bit = MSR_INTEGRITY_CAPS_ARRAY_BIST_BIT,
42 	.test_num = IFS_TYPE_ARRAY_BIST,
43 };
44 
45 static const struct ifs_test_msrs scan_msrs = {
46 	.copy_hashes = MSR_COPY_SCAN_HASHES,
47 	.copy_hashes_status = MSR_SCAN_HASHES_STATUS,
48 	.copy_chunks = MSR_AUTHENTICATE_AND_COPY_CHUNK,
49 	.copy_chunks_status = MSR_CHUNKS_AUTHENTICATION_STATUS,
50 	.test_ctrl = MSR_SAF_CTRL,
51 };
52 
53 static const struct ifs_test_msrs sbaf_msrs = {
54 	.copy_hashes = MSR_COPY_SBAF_HASHES,
55 	.copy_hashes_status = MSR_SBAF_HASHES_STATUS,
56 	.copy_chunks = MSR_AUTHENTICATE_AND_COPY_SBAF_CHUNK,
57 	.copy_chunks_status = MSR_SBAF_CHUNKS_AUTHENTICATION_STATUS,
58 	.test_ctrl = MSR_SBAF_CTRL,
59 };
60 
61 static const struct ifs_test_caps sbaf_test = {
62 	.integrity_cap_bit = MSR_INTEGRITY_CAPS_SBAF_BIT,
63 	.test_num = IFS_TYPE_SBAF,
64 	.image_suffix = "sbft",
65 };
66 
67 static struct ifs_device ifs_devices[] = {
68 	[IFS_TYPE_SAF] = {
69 		.test_caps = &scan_test,
70 		.test_msrs = &scan_msrs,
71 		.misc = {
72 			.name = "intel_ifs_0",
73 			.minor = MISC_DYNAMIC_MINOR,
74 			.groups = plat_ifs_groups,
75 		},
76 	},
77 	[IFS_TYPE_ARRAY_BIST] = {
78 		.test_caps = &array_test,
79 		.misc = {
80 			.name = "intel_ifs_1",
81 			.minor = MISC_DYNAMIC_MINOR,
82 			.groups = plat_ifs_array_groups,
83 		},
84 	},
85 	[IFS_TYPE_SBAF] = {
86 		.test_caps = &sbaf_test,
87 		.test_msrs = &sbaf_msrs,
88 		.misc = {
89 			.name = "intel_ifs_2",
90 			.minor = MISC_DYNAMIC_MINOR,
91 			.groups = plat_ifs_groups,
92 		},
93 	},
94 };
95 
96 #define IFS_NUMTESTS ARRAY_SIZE(ifs_devices)
97 
ifs_cleanup(void)98 static void ifs_cleanup(void)
99 {
100 	int i;
101 
102 	for (i = 0; i < IFS_NUMTESTS; i++) {
103 		if (ifs_devices[i].misc.this_device)
104 			misc_deregister(&ifs_devices[i].misc);
105 	}
106 	kfree(ifs_pkg_auth);
107 }
108 
ifs_init(void)109 static int __init ifs_init(void)
110 {
111 	const struct x86_cpu_id *m;
112 	u64 msrval;
113 	int i, ret;
114 
115 	m = x86_match_cpu(ifs_cpu_ids);
116 	if (!m)
117 		return -ENODEV;
118 
119 	if (rdmsrq_safe(MSR_IA32_CORE_CAPS, &msrval))
120 		return -ENODEV;
121 
122 	if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS))
123 		return -ENODEV;
124 
125 	if (rdmsrq_safe(MSR_INTEGRITY_CAPS, &msrval))
126 		return -ENODEV;
127 
128 	ifs_pkg_auth = kmalloc_array(topology_max_packages(), sizeof(bool), GFP_KERNEL);
129 	if (!ifs_pkg_auth)
130 		return -ENOMEM;
131 
132 	for (i = 0; i < IFS_NUMTESTS; i++) {
133 		if (!(msrval & BIT(ifs_devices[i].test_caps->integrity_cap_bit)))
134 			continue;
135 		ifs_devices[i].rw_data.generation = FIELD_GET(MSR_INTEGRITY_CAPS_SAF_GEN_MASK,
136 							      msrval);
137 		ifs_devices[i].rw_data.array_gen = (u32)m->driver_data;
138 		ret = misc_register(&ifs_devices[i].misc);
139 		if (ret)
140 			goto err_exit;
141 	}
142 	return 0;
143 
144 err_exit:
145 	ifs_cleanup();
146 	return ret;
147 }
148 
ifs_exit(void)149 static void __exit ifs_exit(void)
150 {
151 	ifs_cleanup();
152 }
153 
154 module_init(ifs_init);
155 module_exit(ifs_exit);
156 
157 MODULE_LICENSE("GPL");
158 MODULE_DESCRIPTION("Intel In Field Scan (IFS) device");
159