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