1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2012-2014 Intel Corporation
4 *
5 * Authors:
6 * Xiaoyan Zhang <xiaoyan.zhang@intel.com>
7 * Jiang Liu <jiang.liu@linux.intel.com>
8 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
9 *
10 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
11 *
12 * This file contains implementation of the sysfs interface for PPI.
13 */
14
15
16 #include <linux/acpi.h>
17 #include "tpm.h"
18
19 #define TPM_PPI_REVISION_ID_1 1
20 #define TPM_PPI_REVISION_ID_2 2
21 #define TPM_PPI_FN_VERSION 1
22 #define TPM_PPI_FN_SUBREQ 2
23 #define TPM_PPI_FN_GETREQ 3
24 #define TPM_PPI_FN_GETACT 4
25 #define TPM_PPI_FN_GETRSP 5
26 #define TPM_PPI_FN_SUBREQ2 7
27 #define TPM_PPI_FN_GETOPR 8
28 #define PPI_TPM_REQ_MAX 101 /* PPI 1.3 for TPM 2 */
29 #define PPI_VS_REQ_START 128
30 #define PPI_VS_REQ_END 255
31
32 static const guid_t tpm_ppi_guid =
33 GUID_INIT(0x3DDDFAA6, 0x361B, 0x4EB4,
34 0xA4, 0x24, 0x8D, 0x10, 0x08, 0x9D, 0x16, 0x53);
35
36 static const char * const tpm_ppi_info[] = {
37 "Not implemented",
38 "BIOS only",
39 "Blocked for OS by system firmware",
40 "User required",
41 "User not required",
42 };
43
44 /* A spinlock to protect access to the cache from concurrent reads */
45 static DEFINE_MUTEX(tpm_ppi_lock);
46
47 static u32 ppi_operations_cache[PPI_VS_REQ_END + 1];
48 static bool ppi_cache_populated;
49
tpm_ppi_req_has_parameter(u64 req)50 static bool tpm_ppi_req_has_parameter(u64 req)
51 {
52 return req == 23;
53 }
54
55 static inline union acpi_object *
tpm_eval_dsm(acpi_handle ppi_handle,int func,acpi_object_type type,union acpi_object * argv4,u64 rev)56 tpm_eval_dsm(acpi_handle ppi_handle, int func, acpi_object_type type,
57 union acpi_object *argv4, u64 rev)
58 {
59 BUG_ON(!ppi_handle);
60 return acpi_evaluate_dsm_typed(ppi_handle, &tpm_ppi_guid,
61 rev, func, argv4, type);
62 }
63
tpm_show_ppi_version(struct device * dev,struct device_attribute * attr,char * buf)64 static ssize_t tpm_show_ppi_version(struct device *dev,
65 struct device_attribute *attr, char *buf)
66 {
67 struct tpm_chip *chip = to_tpm_chip(dev);
68
69 return sysfs_emit(buf, "%s\n", chip->ppi_version);
70 }
71
tpm_show_ppi_request(struct device * dev,struct device_attribute * attr,char * buf)72 static ssize_t tpm_show_ppi_request(struct device *dev,
73 struct device_attribute *attr, char *buf)
74 {
75 ssize_t size = -EINVAL;
76 union acpi_object *obj;
77 struct tpm_chip *chip = to_tpm_chip(dev);
78 u64 rev = TPM_PPI_REVISION_ID_2;
79 u64 req;
80
81 if (strcmp(chip->ppi_version, "1.2") < 0)
82 rev = TPM_PPI_REVISION_ID_1;
83
84 obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETREQ,
85 ACPI_TYPE_PACKAGE, NULL, rev);
86 if (!obj)
87 return -ENXIO;
88
89 /*
90 * output.pointer should be of package type, including two integers.
91 * The first is function return code, 0 means success and 1 means
92 * error. The second is pending TPM operation requested by the OS, 0
93 * means none and >0 means operation value.
94 */
95 if (obj->package.count == 3 &&
96 obj->package.elements[0].type == ACPI_TYPE_INTEGER &&
97 obj->package.elements[1].type == ACPI_TYPE_INTEGER &&
98 obj->package.elements[2].type == ACPI_TYPE_INTEGER) {
99 if (obj->package.elements[0].integer.value)
100 size = -EFAULT;
101 else {
102 req = obj->package.elements[1].integer.value;
103 if (tpm_ppi_req_has_parameter(req))
104 size = sysfs_emit(buf, "%llu %llu\n", req,
105 obj->package.elements[2].integer.value);
106 else
107 size = sysfs_emit(buf, "%llu\n", req);
108 }
109 } else if (obj->package.count == 2 &&
110 obj->package.elements[0].type == ACPI_TYPE_INTEGER &&
111 obj->package.elements[1].type == ACPI_TYPE_INTEGER) {
112 if (obj->package.elements[0].integer.value)
113 size = -EFAULT;
114 else
115 size = sysfs_emit(buf, "%llu\n",
116 obj->package.elements[1].integer.value);
117 }
118
119 ACPI_FREE(obj);
120
121 return size;
122 }
123
tpm_store_ppi_request(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)124 static ssize_t tpm_store_ppi_request(struct device *dev,
125 struct device_attribute *attr,
126 const char *buf, size_t count)
127 {
128 u32 req;
129 u64 ret;
130 int func = TPM_PPI_FN_SUBREQ;
131 union acpi_object *obj, tmp[2];
132 union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(2, tmp);
133 struct tpm_chip *chip = to_tpm_chip(dev);
134 u64 rev = TPM_PPI_REVISION_ID_1;
135
136 /*
137 * the function to submit TPM operation request to pre-os environment
138 * is updated with function index from SUBREQ to SUBREQ2 since PPI
139 * version 1.1
140 */
141 if (acpi_check_dsm(chip->acpi_dev_handle, &tpm_ppi_guid,
142 TPM_PPI_REVISION_ID_1, 1 << TPM_PPI_FN_SUBREQ2))
143 func = TPM_PPI_FN_SUBREQ2;
144
145 /*
146 * PPI spec defines params[3].type as ACPI_TYPE_PACKAGE. Some BIOS
147 * accept buffer/string/integer type, but some BIOS accept buffer/
148 * string/package type. For PPI version 1.0 and 1.1, use buffer type
149 * for compatibility, and use package type since 1.2 according to spec.
150 */
151 if (strcmp(chip->ppi_version, "1.3") == 0) {
152 if (sscanf(buf, "%llu %llu", &tmp[0].integer.value,
153 &tmp[1].integer.value) != 2)
154 goto ppi12;
155 rev = TPM_PPI_REVISION_ID_2;
156 tmp[0].type = ACPI_TYPE_INTEGER;
157 tmp[1].type = ACPI_TYPE_INTEGER;
158 } else if (strcmp(chip->ppi_version, "1.2") < 0) {
159 if (sscanf(buf, "%d", &req) != 1)
160 return -EINVAL;
161 argv4.type = ACPI_TYPE_BUFFER;
162 argv4.buffer.length = sizeof(req);
163 argv4.buffer.pointer = (u8 *)&req;
164 } else {
165 ppi12:
166 argv4.package.count = 1;
167 tmp[0].type = ACPI_TYPE_INTEGER;
168 if (sscanf(buf, "%llu", &tmp[0].integer.value) != 1)
169 return -EINVAL;
170 }
171
172 obj = tpm_eval_dsm(chip->acpi_dev_handle, func, ACPI_TYPE_INTEGER,
173 &argv4, rev);
174 if (!obj) {
175 return -ENXIO;
176 } else {
177 ret = obj->integer.value;
178 ACPI_FREE(obj);
179 }
180
181 if (ret == 0)
182 return (acpi_status)count;
183
184 return (ret == 1) ? -EPERM : -EFAULT;
185 }
186
tpm_show_ppi_transition_action(struct device * dev,struct device_attribute * attr,char * buf)187 static ssize_t tpm_show_ppi_transition_action(struct device *dev,
188 struct device_attribute *attr,
189 char *buf)
190 {
191 u32 ret;
192 acpi_status status;
193 union acpi_object *obj = NULL;
194 union acpi_object tmp = {
195 .buffer.type = ACPI_TYPE_BUFFER,
196 .buffer.length = 0,
197 .buffer.pointer = NULL
198 };
199 struct tpm_chip *chip = to_tpm_chip(dev);
200
201 static char *info[] = {
202 "None",
203 "Shutdown",
204 "Reboot",
205 "OS Vendor-specific",
206 "Error",
207 };
208
209 /*
210 * PPI spec defines params[3].type as empty package, but some platforms
211 * (e.g. Capella with PPI 1.0) need integer/string/buffer type, so for
212 * compatibility, define params[3].type as buffer, if PPI version < 1.2
213 */
214 if (strcmp(chip->ppi_version, "1.2") < 0)
215 obj = &tmp;
216 obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETACT,
217 ACPI_TYPE_INTEGER, obj, TPM_PPI_REVISION_ID_1);
218 if (!obj) {
219 return -ENXIO;
220 } else {
221 ret = obj->integer.value;
222 ACPI_FREE(obj);
223 }
224
225 if (ret < ARRAY_SIZE(info) - 1)
226 status = sysfs_emit(buf, "%d: %s\n", ret, info[ret]);
227 else
228 status = sysfs_emit(buf, "%d: %s\n", ret,
229 info[ARRAY_SIZE(info) - 1]);
230 return status;
231 }
232
tpm_show_ppi_response(struct device * dev,struct device_attribute * attr,char * buf)233 static ssize_t tpm_show_ppi_response(struct device *dev,
234 struct device_attribute *attr,
235 char *buf)
236 {
237 acpi_status status = -EINVAL;
238 union acpi_object *obj, *ret_obj;
239 u64 req, res;
240 struct tpm_chip *chip = to_tpm_chip(dev);
241
242 obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETRSP,
243 ACPI_TYPE_PACKAGE, NULL, TPM_PPI_REVISION_ID_1);
244 if (!obj)
245 return -ENXIO;
246
247 /*
248 * parameter output.pointer should be of package type, including
249 * 3 integers. The first means function return code, the second means
250 * most recent TPM operation request, and the last means response to
251 * the most recent TPM operation request. Only if the first is 0, and
252 * the second integer is not 0, the response makes sense.
253 */
254 ret_obj = obj->package.elements;
255 if (obj->package.count < 3 ||
256 ret_obj[0].type != ACPI_TYPE_INTEGER ||
257 ret_obj[1].type != ACPI_TYPE_INTEGER ||
258 ret_obj[2].type != ACPI_TYPE_INTEGER)
259 goto cleanup;
260
261 if (ret_obj[0].integer.value) {
262 status = -EFAULT;
263 goto cleanup;
264 }
265
266 req = ret_obj[1].integer.value;
267 res = ret_obj[2].integer.value;
268 if (req) {
269 if (res == 0)
270 status = sysfs_emit(buf, "%llu %s\n", req,
271 "0: Success");
272 else if (res == 0xFFFFFFF0)
273 status = sysfs_emit(buf, "%llu %s\n", req,
274 "0xFFFFFFF0: User Abort");
275 else if (res == 0xFFFFFFF1)
276 status = sysfs_emit(buf, "%llu %s\n", req,
277 "0xFFFFFFF1: BIOS Failure");
278 else if (res >= 1 && res <= 0x00000FFF)
279 status = sysfs_emit(buf, "%llu %llu: %s\n",
280 req, res, "Corresponding TPM error");
281 else
282 status = sysfs_emit(buf, "%llu %llu: %s\n",
283 req, res, "Error");
284 } else {
285 status = sysfs_emit(buf, "%llu: %s\n",
286 req, "No Recent Request");
287 }
288
289 cleanup:
290 ACPI_FREE(obj);
291 return status;
292 }
293
cache_ppi_operations(acpi_handle dev_handle,char * buf)294 static ssize_t cache_ppi_operations(acpi_handle dev_handle, char *buf)
295 {
296 int i;
297 u32 ret;
298 int len = 0;
299 union acpi_object *obj, tmp;
300 union acpi_object argv = ACPI_INIT_DSM_ARGV4(1, &tmp);
301
302 if (!acpi_check_dsm(dev_handle, &tpm_ppi_guid, TPM_PPI_REVISION_ID_1,
303 1 << TPM_PPI_FN_GETOPR))
304 return -EPERM;
305
306 tmp.integer.type = ACPI_TYPE_INTEGER;
307 for (i = 0; i <= PPI_VS_REQ_END; i++) {
308 tmp.integer.value = i;
309 obj = tpm_eval_dsm(dev_handle, TPM_PPI_FN_GETOPR,
310 ACPI_TYPE_INTEGER, &argv,
311 TPM_PPI_REVISION_ID_1);
312 if (!obj)
313 return -ENOMEM;
314
315 ret = obj->integer.value;
316 ppi_operations_cache[i] = ret;
317 ACPI_FREE(obj);
318 }
319
320 return len;
321 }
322
tpm_show_ppi_tcg_operations(struct device * dev,struct device_attribute * attr,char * buf)323 static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
324 struct device_attribute *attr,
325 char *buf)
326 {
327 struct tpm_chip *chip = to_tpm_chip(dev);
328 ssize_t len = 0;
329 u32 ret;
330 int i;
331
332 mutex_lock(&tpm_ppi_lock);
333 if (!ppi_cache_populated) {
334 len = cache_ppi_operations(chip->acpi_dev_handle, buf);
335 if (len < 0) {
336 mutex_unlock(&tpm_ppi_lock);
337 return len;
338 }
339
340 ppi_cache_populated = true;
341 }
342
343 for (i = 0; i <= PPI_TPM_REQ_MAX; i++) {
344 ret = ppi_operations_cache[i];
345 if (ret >= 0 && ret < ARRAY_SIZE(tpm_ppi_info))
346 len += sysfs_emit_at(buf, len, "%d %d: %s\n",
347 i, ret, tpm_ppi_info[ret]);
348 }
349 mutex_unlock(&tpm_ppi_lock);
350
351 return len;
352 }
353
tpm_show_ppi_vs_operations(struct device * dev,struct device_attribute * attr,char * buf)354 static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
355 struct device_attribute *attr,
356 char *buf)
357 {
358 struct tpm_chip *chip = to_tpm_chip(dev);
359 ssize_t len = 0;
360 u32 ret;
361 int i;
362
363 mutex_lock(&tpm_ppi_lock);
364 if (!ppi_cache_populated) {
365 len = cache_ppi_operations(chip->acpi_dev_handle, buf);
366 if (len < 0) {
367 mutex_unlock(&tpm_ppi_lock);
368 return len;
369 }
370
371 ppi_cache_populated = true;
372 }
373
374 for (i = PPI_VS_REQ_START; i <= PPI_VS_REQ_END; i++) {
375 ret = ppi_operations_cache[i];
376 if (ret >= 0 && ret < ARRAY_SIZE(tpm_ppi_info))
377 len += sysfs_emit_at(buf, len, "%d %d: %s\n",
378 i, ret, tpm_ppi_info[ret]);
379 }
380 mutex_unlock(&tpm_ppi_lock);
381
382 return len;
383 }
384
385 static DEVICE_ATTR(version, S_IRUGO, tpm_show_ppi_version, NULL);
386 static DEVICE_ATTR(request, S_IRUGO | S_IWUSR | S_IWGRP,
387 tpm_show_ppi_request, tpm_store_ppi_request);
388 static DEVICE_ATTR(transition_action, S_IRUGO,
389 tpm_show_ppi_transition_action, NULL);
390 static DEVICE_ATTR(response, S_IRUGO, tpm_show_ppi_response, NULL);
391 static DEVICE_ATTR(tcg_operations, S_IRUGO, tpm_show_ppi_tcg_operations, NULL);
392 static DEVICE_ATTR(vs_operations, S_IRUGO, tpm_show_ppi_vs_operations, NULL);
393
394 static struct attribute *ppi_attrs[] = {
395 &dev_attr_version.attr,
396 &dev_attr_request.attr,
397 &dev_attr_transition_action.attr,
398 &dev_attr_response.attr,
399 &dev_attr_tcg_operations.attr,
400 &dev_attr_vs_operations.attr, NULL,
401 };
402 static const struct attribute_group ppi_attr_grp = {
403 .name = "ppi",
404 .attrs = ppi_attrs
405 };
406
tpm_add_ppi(struct tpm_chip * chip)407 void tpm_add_ppi(struct tpm_chip *chip)
408 {
409 union acpi_object *obj;
410
411 if (!chip->acpi_dev_handle)
412 return;
413
414 if (!acpi_check_dsm(chip->acpi_dev_handle, &tpm_ppi_guid,
415 TPM_PPI_REVISION_ID_1, 1 << TPM_PPI_FN_VERSION))
416 return;
417
418 /* Cache PPI version string. */
419 obj = acpi_evaluate_dsm_typed(chip->acpi_dev_handle, &tpm_ppi_guid,
420 TPM_PPI_REVISION_ID_1,
421 TPM_PPI_FN_VERSION,
422 NULL, ACPI_TYPE_STRING);
423 if (obj) {
424 strscpy(chip->ppi_version, obj->string.pointer,
425 sizeof(chip->ppi_version));
426 ACPI_FREE(obj);
427 }
428
429 chip->groups[chip->groups_cnt++] = &ppi_attr_grp;
430 }
431