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 bool tpm_ppi_req_has_parameter(u64 req) 37 { 38 return req == 23; 39 } 40 41 static inline union acpi_object * 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 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 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 } 111 112 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 } 174 175 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 } 220 221 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 } 281 282 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 } 323 324 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 } 333 334 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 }; 365 366 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 strlcpy(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