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 scnprintf(buf, PAGE_SIZE, "%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 = scnprintf(buf, PAGE_SIZE,
91 "%llu %llu\n", req,
92 obj->package.elements[2].integer.value);
93 else
94 size = scnprintf(buf, PAGE_SIZE,
95 "%llu\n", req);
96 }
97 } else if (obj->package.count == 2 &&
98 obj->package.elements[0].type == ACPI_TYPE_INTEGER &&
99 obj->package.elements[1].type == ACPI_TYPE_INTEGER) {
100 if (obj->package.elements[0].integer.value)
101 size = -EFAULT;
102 else
103 size = scnprintf(buf, PAGE_SIZE, "%llu\n",
104 obj->package.elements[1].integer.value);
105 }
106
107 ACPI_FREE(obj);
108
109 return size;
110 }
111
tpm_store_ppi_request(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)112 static ssize_t tpm_store_ppi_request(struct device *dev,
113 struct device_attribute *attr,
114 const char *buf, size_t count)
115 {
116 u32 req;
117 u64 ret;
118 int func = TPM_PPI_FN_SUBREQ;
119 union acpi_object *obj, tmp[2];
120 union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(2, tmp);
121 struct tpm_chip *chip = to_tpm_chip(dev);
122 u64 rev = TPM_PPI_REVISION_ID_1;
123
124 /*
125 * the function to submit TPM operation request to pre-os environment
126 * is updated with function index from SUBREQ to SUBREQ2 since PPI
127 * version 1.1
128 */
129 if (acpi_check_dsm(chip->acpi_dev_handle, &tpm_ppi_guid,
130 TPM_PPI_REVISION_ID_1, 1 << TPM_PPI_FN_SUBREQ2))
131 func = TPM_PPI_FN_SUBREQ2;
132
133 /*
134 * PPI spec defines params[3].type as ACPI_TYPE_PACKAGE. Some BIOS
135 * accept buffer/string/integer type, but some BIOS accept buffer/
136 * string/package type. For PPI version 1.0 and 1.1, use buffer type
137 * for compatibility, and use package type since 1.2 according to spec.
138 */
139 if (strcmp(chip->ppi_version, "1.3") == 0) {
140 if (sscanf(buf, "%llu %llu", &tmp[0].integer.value,
141 &tmp[1].integer.value) != 2)
142 goto ppi12;
143 rev = TPM_PPI_REVISION_ID_2;
144 tmp[0].type = ACPI_TYPE_INTEGER;
145 tmp[1].type = ACPI_TYPE_INTEGER;
146 } else if (strcmp(chip->ppi_version, "1.2") < 0) {
147 if (sscanf(buf, "%d", &req) != 1)
148 return -EINVAL;
149 argv4.type = ACPI_TYPE_BUFFER;
150 argv4.buffer.length = sizeof(req);
151 argv4.buffer.pointer = (u8 *)&req;
152 } else {
153 ppi12:
154 argv4.package.count = 1;
155 tmp[0].type = ACPI_TYPE_INTEGER;
156 if (sscanf(buf, "%llu", &tmp[0].integer.value) != 1)
157 return -EINVAL;
158 }
159
160 obj = tpm_eval_dsm(chip->acpi_dev_handle, func, ACPI_TYPE_INTEGER,
161 &argv4, rev);
162 if (!obj) {
163 return -ENXIO;
164 } else {
165 ret = obj->integer.value;
166 ACPI_FREE(obj);
167 }
168
169 if (ret == 0)
170 return (acpi_status)count;
171
172 return (ret == 1) ? -EPERM : -EFAULT;
173 }
174
tpm_show_ppi_transition_action(struct device * dev,struct device_attribute * attr,char * buf)175 static ssize_t tpm_show_ppi_transition_action(struct device *dev,
176 struct device_attribute *attr,
177 char *buf)
178 {
179 u32 ret;
180 acpi_status status;
181 union acpi_object *obj = NULL;
182 union acpi_object tmp = {
183 .buffer.type = ACPI_TYPE_BUFFER,
184 .buffer.length = 0,
185 .buffer.pointer = NULL
186 };
187 struct tpm_chip *chip = to_tpm_chip(dev);
188
189 static char *info[] = {
190 "None",
191 "Shutdown",
192 "Reboot",
193 "OS Vendor-specific",
194 "Error",
195 };
196
197 /*
198 * PPI spec defines params[3].type as empty package, but some platforms
199 * (e.g. Capella with PPI 1.0) need integer/string/buffer type, so for
200 * compatibility, define params[3].type as buffer, if PPI version < 1.2
201 */
202 if (strcmp(chip->ppi_version, "1.2") < 0)
203 obj = &tmp;
204 obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETACT,
205 ACPI_TYPE_INTEGER, obj, TPM_PPI_REVISION_ID_1);
206 if (!obj) {
207 return -ENXIO;
208 } else {
209 ret = obj->integer.value;
210 ACPI_FREE(obj);
211 }
212
213 if (ret < ARRAY_SIZE(info) - 1)
214 status = scnprintf(buf, PAGE_SIZE, "%d: %s\n", ret, info[ret]);
215 else
216 status = scnprintf(buf, PAGE_SIZE, "%d: %s\n", ret,
217 info[ARRAY_SIZE(info)-1]);
218 return status;
219 }
220
tpm_show_ppi_response(struct device * dev,struct device_attribute * attr,char * buf)221 static ssize_t tpm_show_ppi_response(struct device *dev,
222 struct device_attribute *attr,
223 char *buf)
224 {
225 acpi_status status = -EINVAL;
226 union acpi_object *obj, *ret_obj;
227 u64 req, res;
228 struct tpm_chip *chip = to_tpm_chip(dev);
229
230 obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETRSP,
231 ACPI_TYPE_PACKAGE, NULL, TPM_PPI_REVISION_ID_1);
232 if (!obj)
233 return -ENXIO;
234
235 /*
236 * parameter output.pointer should be of package type, including
237 * 3 integers. The first means function return code, the second means
238 * most recent TPM operation request, and the last means response to
239 * the most recent TPM operation request. Only if the first is 0, and
240 * the second integer is not 0, the response makes sense.
241 */
242 ret_obj = obj->package.elements;
243 if (obj->package.count < 3 ||
244 ret_obj[0].type != ACPI_TYPE_INTEGER ||
245 ret_obj[1].type != ACPI_TYPE_INTEGER ||
246 ret_obj[2].type != ACPI_TYPE_INTEGER)
247 goto cleanup;
248
249 if (ret_obj[0].integer.value) {
250 status = -EFAULT;
251 goto cleanup;
252 }
253
254 req = ret_obj[1].integer.value;
255 res = ret_obj[2].integer.value;
256 if (req) {
257 if (res == 0)
258 status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
259 "0: Success");
260 else if (res == 0xFFFFFFF0)
261 status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
262 "0xFFFFFFF0: User Abort");
263 else if (res == 0xFFFFFFF1)
264 status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
265 "0xFFFFFFF1: BIOS Failure");
266 else if (res >= 1 && res <= 0x00000FFF)
267 status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
268 req, res, "Corresponding TPM error");
269 else
270 status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
271 req, res, "Error");
272 } else {
273 status = scnprintf(buf, PAGE_SIZE, "%llu: %s\n",
274 req, "No Recent Request");
275 }
276
277 cleanup:
278 ACPI_FREE(obj);
279 return status;
280 }
281
show_ppi_operations(acpi_handle dev_handle,char * buf,u32 start,u32 end)282 static ssize_t show_ppi_operations(acpi_handle dev_handle, char *buf, u32 start,
283 u32 end)
284 {
285 int i;
286 u32 ret;
287 char *str = buf;
288 union acpi_object *obj, tmp;
289 union acpi_object argv = ACPI_INIT_DSM_ARGV4(1, &tmp);
290
291 static char *info[] = {
292 "Not implemented",
293 "BIOS only",
294 "Blocked for OS by BIOS",
295 "User required",
296 "User not required",
297 };
298
299 if (!acpi_check_dsm(dev_handle, &tpm_ppi_guid, TPM_PPI_REVISION_ID_1,
300 1 << TPM_PPI_FN_GETOPR))
301 return -EPERM;
302
303 tmp.integer.type = ACPI_TYPE_INTEGER;
304 for (i = start; i <= end; i++) {
305 tmp.integer.value = i;
306 obj = tpm_eval_dsm(dev_handle, TPM_PPI_FN_GETOPR,
307 ACPI_TYPE_INTEGER, &argv,
308 TPM_PPI_REVISION_ID_1);
309 if (!obj) {
310 return -ENOMEM;
311 } else {
312 ret = obj->integer.value;
313 ACPI_FREE(obj);
314 }
315
316 if (ret > 0 && ret < ARRAY_SIZE(info))
317 str += scnprintf(str, PAGE_SIZE, "%d %d: %s\n",
318 i, ret, info[ret]);
319 }
320
321 return str - buf;
322 }
323
tpm_show_ppi_tcg_operations(struct device * dev,struct device_attribute * attr,char * buf)324 static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
325 struct device_attribute *attr,
326 char *buf)
327 {
328 struct tpm_chip *chip = to_tpm_chip(dev);
329
330 return show_ppi_operations(chip->acpi_dev_handle, buf, 0,
331 PPI_TPM_REQ_MAX);
332 }
333
tpm_show_ppi_vs_operations(struct device * dev,struct device_attribute * attr,char * buf)334 static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
335 struct device_attribute *attr,
336 char *buf)
337 {
338 struct tpm_chip *chip = to_tpm_chip(dev);
339
340 return show_ppi_operations(chip->acpi_dev_handle, buf, PPI_VS_REQ_START,
341 PPI_VS_REQ_END);
342 }
343
344 static DEVICE_ATTR(version, S_IRUGO, tpm_show_ppi_version, NULL);
345 static DEVICE_ATTR(request, S_IRUGO | S_IWUSR | S_IWGRP,
346 tpm_show_ppi_request, tpm_store_ppi_request);
347 static DEVICE_ATTR(transition_action, S_IRUGO,
348 tpm_show_ppi_transition_action, NULL);
349 static DEVICE_ATTR(response, S_IRUGO, tpm_show_ppi_response, NULL);
350 static DEVICE_ATTR(tcg_operations, S_IRUGO, tpm_show_ppi_tcg_operations, NULL);
351 static DEVICE_ATTR(vs_operations, S_IRUGO, tpm_show_ppi_vs_operations, NULL);
352
353 static struct attribute *ppi_attrs[] = {
354 &dev_attr_version.attr,
355 &dev_attr_request.attr,
356 &dev_attr_transition_action.attr,
357 &dev_attr_response.attr,
358 &dev_attr_tcg_operations.attr,
359 &dev_attr_vs_operations.attr, NULL,
360 };
361 static const struct attribute_group ppi_attr_grp = {
362 .name = "ppi",
363 .attrs = ppi_attrs
364 };
365
tpm_add_ppi(struct tpm_chip * chip)366 void tpm_add_ppi(struct tpm_chip *chip)
367 {
368 union acpi_object *obj;
369
370 if (!chip->acpi_dev_handle)
371 return;
372
373 if (!acpi_check_dsm(chip->acpi_dev_handle, &tpm_ppi_guid,
374 TPM_PPI_REVISION_ID_1, 1 << TPM_PPI_FN_VERSION))
375 return;
376
377 /* Cache PPI version string. */
378 obj = acpi_evaluate_dsm_typed(chip->acpi_dev_handle, &tpm_ppi_guid,
379 TPM_PPI_REVISION_ID_1,
380 TPM_PPI_FN_VERSION,
381 NULL, ACPI_TYPE_STRING);
382 if (obj) {
383 strscpy(chip->ppi_version, obj->string.pointer,
384 sizeof(chip->ppi_version));
385 ACPI_FREE(obj);
386 }
387
388 chip->groups[chip->groups_cnt++] = &ppi_attr_grp;
389 }
390