1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright(c) 2022 Intel Corporation. */
3 
4 #include <linux/firmware.h>
5 #include <asm/cpu.h>
6 #include <linux/slab.h>
7 #include <asm/microcode_intel.h>
8 
9 #include "ifs.h"
10 
11 struct ifs_header {
12 	u32 header_ver;
13 	u32 blob_revision;
14 	u32 date;
15 	u32 processor_sig;
16 	u32 check_sum;
17 	u32 loader_rev;
18 	u32 processor_flags;
19 	u32 metadata_size;
20 	u32 total_size;
21 	u32 fusa_info;
22 	u64 reserved;
23 };
24 
25 #define IFS_HEADER_SIZE	(sizeof(struct ifs_header))
26 static struct ifs_header *ifs_header_ptr;	/* pointer to the ifs image header */
27 static u64 ifs_hash_ptr;			/* Address of ifs metadata (hash) */
28 static u64 ifs_test_image_ptr;			/* 256B aligned address of test pattern */
29 static DECLARE_COMPLETION(ifs_done);
30 
31 static const char * const scan_hash_status[] = {
32 	[0] = "No error reported",
33 	[1] = "Attempt to copy scan hashes when copy already in progress",
34 	[2] = "Secure Memory not set up correctly",
35 	[3] = "FuSaInfo.ProgramID does not match or ff-mm-ss does not match",
36 	[4] = "Reserved",
37 	[5] = "Integrity check failed",
38 	[6] = "Scan reload or test is in progress"
39 };
40 
41 static const char * const scan_authentication_status[] = {
42 	[0] = "No error reported",
43 	[1] = "Attempt to authenticate a chunk which is already marked as authentic",
44 	[2] = "Chunk authentication error. The hash of chunk did not match expected value"
45 };
46 
47 /*
48  * To copy scan hashes and authenticate test chunks, the initiating cpu must point
49  * to the EDX:EAX to the test image in linear address.
50  * Run wrmsr(MSR_COPY_SCAN_HASHES) for scan hash copy and run wrmsr(MSR_AUTHENTICATE_AND_COPY_CHUNK)
51  * for scan hash copy and test chunk authentication.
52  */
copy_hashes_authenticate_chunks(struct work_struct * work)53 static void copy_hashes_authenticate_chunks(struct work_struct *work)
54 {
55 	struct ifs_work *local_work = container_of(work, struct ifs_work, w);
56 	union ifs_scan_hashes_status hashes_status;
57 	union ifs_chunks_auth_status chunk_status;
58 	struct device *dev = local_work->dev;
59 	int i, num_chunks, chunk_size;
60 	struct ifs_data *ifsd;
61 	u64 linear_addr, base;
62 	u32 err_code;
63 
64 	ifsd = ifs_get_data(dev);
65 	/* run scan hash copy */
66 	wrmsrl(MSR_COPY_SCAN_HASHES, ifs_hash_ptr);
67 	rdmsrl(MSR_SCAN_HASHES_STATUS, hashes_status.data);
68 
69 	/* enumerate the scan image information */
70 	num_chunks = hashes_status.num_chunks;
71 	chunk_size = hashes_status.chunk_size * 1024;
72 	err_code = hashes_status.error_code;
73 
74 	if (!hashes_status.valid) {
75 		ifsd->loading_error = true;
76 		if (err_code >= ARRAY_SIZE(scan_hash_status)) {
77 			dev_err(dev, "invalid error code 0x%x for hash copy\n", err_code);
78 			goto done;
79 		}
80 		dev_err(dev, "Hash copy error : %s", scan_hash_status[err_code]);
81 		goto done;
82 	}
83 
84 	/* base linear address to the scan data */
85 	base = ifs_test_image_ptr;
86 
87 	/* scan data authentication and copy chunks to secured memory */
88 	for (i = 0; i < num_chunks; i++) {
89 		linear_addr = base + i * chunk_size;
90 		linear_addr |= i;
91 
92 		wrmsrl(MSR_AUTHENTICATE_AND_COPY_CHUNK, linear_addr);
93 		rdmsrl(MSR_CHUNKS_AUTHENTICATION_STATUS, chunk_status.data);
94 
95 		ifsd->valid_chunks = chunk_status.valid_chunks;
96 		err_code = chunk_status.error_code;
97 
98 		if (err_code) {
99 			ifsd->loading_error = true;
100 			if (err_code >= ARRAY_SIZE(scan_authentication_status)) {
101 				dev_err(dev,
102 					"invalid error code 0x%x for authentication\n", err_code);
103 				goto done;
104 			}
105 			dev_err(dev, "Chunk authentication error %s\n",
106 				scan_authentication_status[err_code]);
107 			goto done;
108 		}
109 	}
110 done:
111 	complete(&ifs_done);
112 }
113 
114 /*
115  * IFS requires scan chunks authenticated per each socket in the platform.
116  * Once the test chunk is authenticated, it is automatically copied to secured memory
117  * and proceed the authentication for the next chunk.
118  */
scan_chunks_sanity_check(struct device * dev)119 static int scan_chunks_sanity_check(struct device *dev)
120 {
121 	int metadata_size, curr_pkg, cpu, ret = -ENOMEM;
122 	struct ifs_data *ifsd = ifs_get_data(dev);
123 	bool *package_authenticated;
124 	struct ifs_work local_work;
125 	char *test_ptr;
126 
127 	package_authenticated = kcalloc(topology_max_packages(), sizeof(bool), GFP_KERNEL);
128 	if (!package_authenticated)
129 		return ret;
130 
131 	metadata_size = ifs_header_ptr->metadata_size;
132 
133 	/* Spec says that if the Meta Data Size = 0 then it should be treated as 2000 */
134 	if (metadata_size == 0)
135 		metadata_size = 2000;
136 
137 	/* Scan chunk start must be 256 byte aligned */
138 	if ((metadata_size + IFS_HEADER_SIZE) % 256) {
139 		dev_err(dev, "Scan pattern offset within the binary is not 256 byte aligned\n");
140 		return -EINVAL;
141 	}
142 
143 	test_ptr = (char *)ifs_header_ptr + IFS_HEADER_SIZE + metadata_size;
144 	ifsd->loading_error = false;
145 
146 	ifs_test_image_ptr = (u64)test_ptr;
147 	ifsd->loaded_version = ifs_header_ptr->blob_revision;
148 
149 	/* copy the scan hash and authenticate per package */
150 	cpus_read_lock();
151 	for_each_online_cpu(cpu) {
152 		curr_pkg = topology_physical_package_id(cpu);
153 		if (package_authenticated[curr_pkg])
154 			continue;
155 		reinit_completion(&ifs_done);
156 		local_work.dev = dev;
157 		INIT_WORK(&local_work.w, copy_hashes_authenticate_chunks);
158 		schedule_work_on(cpu, &local_work.w);
159 		wait_for_completion(&ifs_done);
160 		if (ifsd->loading_error)
161 			goto out;
162 		package_authenticated[curr_pkg] = 1;
163 	}
164 	ret = 0;
165 out:
166 	cpus_read_unlock();
167 	kfree(package_authenticated);
168 
169 	return ret;
170 }
171 
ifs_sanity_check(struct device * dev,const struct microcode_header_intel * mc_header)172 static int ifs_sanity_check(struct device *dev,
173 			    const struct microcode_header_intel *mc_header)
174 {
175 	unsigned long total_size, data_size;
176 	u32 sum, *mc;
177 
178 	total_size = get_totalsize(mc_header);
179 	data_size = get_datasize(mc_header);
180 
181 	if ((data_size + MC_HEADER_SIZE > total_size) || (total_size % sizeof(u32))) {
182 		dev_err(dev, "bad ifs data file size.\n");
183 		return -EINVAL;
184 	}
185 
186 	if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
187 		dev_err(dev, "invalid/unknown ifs update format.\n");
188 		return -EINVAL;
189 	}
190 
191 	mc = (u32 *)mc_header;
192 	sum = 0;
193 	for (int i = 0; i < total_size / sizeof(u32); i++)
194 		sum += mc[i];
195 
196 	if (sum) {
197 		dev_err(dev, "bad ifs data checksum, aborting.\n");
198 		return -EINVAL;
199 	}
200 
201 	return 0;
202 }
203 
find_ifs_matching_signature(struct device * dev,struct ucode_cpu_info * uci,const struct microcode_header_intel * shdr)204 static bool find_ifs_matching_signature(struct device *dev, struct ucode_cpu_info *uci,
205 					const struct microcode_header_intel *shdr)
206 {
207 	unsigned int mc_size;
208 
209 	mc_size = get_totalsize(shdr);
210 
211 	if (!mc_size || ifs_sanity_check(dev, shdr) < 0) {
212 		dev_err(dev, "ifs sanity check failure\n");
213 		return false;
214 	}
215 
216 	if (!intel_cpu_signatures_match(uci->cpu_sig.sig, uci->cpu_sig.pf, shdr->sig, shdr->pf)) {
217 		dev_err(dev, "ifs signature, pf not matching\n");
218 		return false;
219 	}
220 
221 	return true;
222 }
223 
ifs_image_sanity_check(struct device * dev,const struct microcode_header_intel * data)224 static bool ifs_image_sanity_check(struct device *dev, const struct microcode_header_intel *data)
225 {
226 	struct ucode_cpu_info uci;
227 
228 	intel_cpu_collect_info(&uci);
229 
230 	return find_ifs_matching_signature(dev, &uci, data);
231 }
232 
233 /*
234  * Load ifs image. Before loading ifs module, the ifs image must be located
235  * in /lib/firmware/intel/ifs and named as {family/model/stepping}.{testname}.
236  */
ifs_load_firmware(struct device * dev)237 void ifs_load_firmware(struct device *dev)
238 {
239 	struct ifs_data *ifsd = ifs_get_data(dev);
240 	const struct firmware *fw;
241 	char scan_path[32];
242 	int ret;
243 
244 	snprintf(scan_path, sizeof(scan_path), "intel/ifs/%02x-%02x-%02x.scan",
245 		 boot_cpu_data.x86, boot_cpu_data.x86_model, boot_cpu_data.x86_stepping);
246 
247 	ret = request_firmware_direct(&fw, scan_path, dev);
248 	if (ret) {
249 		dev_err(dev, "ifs file %s load failed\n", scan_path);
250 		goto done;
251 	}
252 
253 	if (!ifs_image_sanity_check(dev, (struct microcode_header_intel *)fw->data)) {
254 		dev_err(dev, "ifs header sanity check failed\n");
255 		goto release;
256 	}
257 
258 	ifs_header_ptr = (struct ifs_header *)fw->data;
259 	ifs_hash_ptr = (u64)(ifs_header_ptr + 1);
260 
261 	ret = scan_chunks_sanity_check(dev);
262 release:
263 	release_firmware(fw);
264 done:
265 	ifsd->loaded = (ret == 0);
266 }
267