1// SPDX-License-Identifier: GPL-2.0-only 2/* acpi_thermal_rel.c driver for exporting ACPI thermal relationship 3 * 4 * Copyright (c) 2014 Intel Corp 5 */ 6 7/* 8 * Two functionalities included: 9 * 1. Export _TRT, _ART, via misc device interface to the userspace. 10 * 2. Provide parsing result to kernel drivers 11 * 12 */ 13#include <linux/init.h> 14#include <linux/export.h> 15#include <linux/module.h> 16#include <linux/device.h> 17#include <linux/platform_device.h> 18#include <linux/io.h> 19#include <linux/acpi.h> 20#include <linux/uaccess.h> 21#include <linux/miscdevice.h> 22#include <linux/fs.h> 23#include "acpi_thermal_rel.h" 24 25static acpi_handle acpi_thermal_rel_handle; 26static DEFINE_SPINLOCK(acpi_thermal_rel_chrdev_lock); 27static int acpi_thermal_rel_chrdev_count; /* #times opened */ 28static int acpi_thermal_rel_chrdev_exclu; /* already open exclusive? */ 29 30static int acpi_thermal_rel_open(struct inode *inode, struct file *file) 31{ 32 spin_lock(&acpi_thermal_rel_chrdev_lock); 33 if (acpi_thermal_rel_chrdev_exclu || 34 (acpi_thermal_rel_chrdev_count && (file->f_flags & O_EXCL))) { 35 spin_unlock(&acpi_thermal_rel_chrdev_lock); 36 return -EBUSY; 37 } 38 39 if (file->f_flags & O_EXCL) 40 acpi_thermal_rel_chrdev_exclu = 1; 41 acpi_thermal_rel_chrdev_count++; 42 43 spin_unlock(&acpi_thermal_rel_chrdev_lock); 44 45 return nonseekable_open(inode, file); 46} 47 48static int acpi_thermal_rel_release(struct inode *inode, struct file *file) 49{ 50 spin_lock(&acpi_thermal_rel_chrdev_lock); 51 acpi_thermal_rel_chrdev_count--; 52 acpi_thermal_rel_chrdev_exclu = 0; 53 spin_unlock(&acpi_thermal_rel_chrdev_lock); 54 55 return 0; 56} 57 58/** 59 * acpi_parse_trt - Thermal Relationship Table _TRT for passive cooling 60 * 61 * @handle: ACPI handle of the device contains _TRT 62 * @trt_count: the number of valid entries resulted from parsing _TRT 63 * @trtp: pointer to pointer of array of _TRT entries in parsing result 64 * @create_dev: whether to create platform devices for target and source 65 * 66 */ 67int acpi_parse_trt(acpi_handle handle, int *trt_count, struct trt **trtp, 68 bool create_dev) 69{ 70 acpi_status status; 71 int result = 0; 72 int i; 73 int nr_bad_entries = 0; 74 struct trt *trts; 75 union acpi_object *p; 76 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 77 struct acpi_buffer element = { 0, NULL }; 78 struct acpi_buffer trt_format = { sizeof("RRNNNNNN"), "RRNNNNNN" }; 79 80 status = acpi_evaluate_object(handle, "_TRT", NULL, &buffer); 81 if (ACPI_FAILURE(status)) 82 return -ENODEV; 83 84 p = buffer.pointer; 85 if (!p || (p->type != ACPI_TYPE_PACKAGE)) { 86 pr_err("Invalid _TRT data\n"); 87 result = -EFAULT; 88 goto end; 89 } 90 91 *trt_count = p->package.count; 92 trts = kcalloc(*trt_count, sizeof(struct trt), GFP_KERNEL); 93 if (!trts) { 94 result = -ENOMEM; 95 goto end; 96 } 97 98 for (i = 0; i < *trt_count; i++) { 99 struct trt *trt = &trts[i - nr_bad_entries]; 100 101 element.length = sizeof(struct trt); 102 element.pointer = trt; 103 104 status = acpi_extract_package(&(p->package.elements[i]), 105 &trt_format, &element); 106 if (ACPI_FAILURE(status)) { 107 nr_bad_entries++; 108 pr_warn("_TRT package %d is invalid, ignored\n", i); 109 continue; 110 } 111 if (!create_dev) 112 continue; 113 114 if (!acpi_fetch_acpi_dev(trt->source)) 115 pr_warn("Failed to get source ACPI device\n"); 116 117 if (!acpi_fetch_acpi_dev(trt->target)) 118 pr_warn("Failed to get target ACPI device\n"); 119 } 120 121 result = 0; 122 123 *trtp = trts; 124 /* don't count bad entries */ 125 *trt_count -= nr_bad_entries; 126end: 127 kfree(buffer.pointer); 128 return result; 129} 130EXPORT_SYMBOL(acpi_parse_trt); 131 132/** 133 * acpi_parse_art - Parse Active Relationship Table _ART 134 * 135 * @handle: ACPI handle of the device contains _ART 136 * @art_count: the number of valid entries resulted from parsing _ART 137 * @artp: pointer to pointer of array of art entries in parsing result 138 * @create_dev: whether to create platform devices for target and source 139 * 140 */ 141int acpi_parse_art(acpi_handle handle, int *art_count, struct art **artp, 142 bool create_dev) 143{ 144 acpi_status status; 145 int result = 0; 146 int i; 147 int nr_bad_entries = 0; 148 struct art *arts; 149 union acpi_object *p; 150 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 151 struct acpi_buffer element = { 0, NULL }; 152 struct acpi_buffer art_format = { 153 sizeof("RRNNNNNNNNNNN"), "RRNNNNNNNNNNN" }; 154 155 status = acpi_evaluate_object(handle, "_ART", NULL, &buffer); 156 if (ACPI_FAILURE(status)) 157 return -ENODEV; 158 159 p = buffer.pointer; 160 if (!p || (p->type != ACPI_TYPE_PACKAGE)) { 161 pr_err("Invalid _ART data\n"); 162 result = -EFAULT; 163 goto end; 164 } 165 166 /* ignore p->package.elements[0], as this is _ART Revision field */ 167 *art_count = p->package.count - 1; 168 arts = kcalloc(*art_count, sizeof(struct art), GFP_KERNEL); 169 if (!arts) { 170 result = -ENOMEM; 171 goto end; 172 } 173 174 for (i = 0; i < *art_count; i++) { 175 struct art *art = &arts[i - nr_bad_entries]; 176 177 element.length = sizeof(struct art); 178 element.pointer = art; 179 180 status = acpi_extract_package(&(p->package.elements[i + 1]), 181 &art_format, &element); 182 if (ACPI_FAILURE(status)) { 183 pr_warn("_ART package %d is invalid, ignored", i); 184 nr_bad_entries++; 185 continue; 186 } 187 if (!create_dev) 188 continue; 189 190 if (!acpi_fetch_acpi_dev(art->source)) 191 pr_warn("Failed to get source ACPI device\n"); 192 193 if (!acpi_fetch_acpi_dev(art->target)) 194 pr_warn("Failed to get target ACPI device\n"); 195 } 196 197 *artp = arts; 198 /* don't count bad entries */ 199 *art_count -= nr_bad_entries; 200end: 201 kfree(buffer.pointer); 202 return result; 203} 204EXPORT_SYMBOL(acpi_parse_art); 205 206/* 207 * acpi_parse_psvt - Passive Table (PSVT) for passive cooling 208 * 209 * @handle: ACPI handle of the device which contains PSVT 210 * @psvt_count: the number of valid entries resulted from parsing PSVT 211 * @psvtp: pointer to array of psvt entries 212 * 213 */ 214static int acpi_parse_psvt(acpi_handle handle, int *psvt_count, struct psvt **psvtp) 215{ 216 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 217 int nr_bad_entries = 0, revision = 0; 218 union acpi_object *p; 219 acpi_status status; 220 int i, result = 0; 221 struct psvt *psvts; 222 223 if (!acpi_has_method(handle, "PSVT")) 224 return -ENODEV; 225 226 status = acpi_evaluate_object(handle, "PSVT", NULL, &buffer); 227 if (ACPI_FAILURE(status)) 228 return -ENODEV; 229 230 p = buffer.pointer; 231 if (!p || (p->type != ACPI_TYPE_PACKAGE)) { 232 result = -EFAULT; 233 goto end; 234 } 235 236 /* first package is the revision number */ 237 if (p->package.count > 0) { 238 union acpi_object *prev = &(p->package.elements[0]); 239 240 if (prev->type == ACPI_TYPE_INTEGER) 241 revision = (int)prev->integer.value; 242 } else { 243 result = -EFAULT; 244 goto end; 245 } 246 247 /* Support only version 2 */ 248 if (revision != 2) { 249 result = -EFAULT; 250 goto end; 251 } 252 253 *psvt_count = p->package.count - 1; 254 if (!*psvt_count) { 255 result = -EFAULT; 256 goto end; 257 } 258 259 psvts = kcalloc(*psvt_count, sizeof(*psvts), GFP_KERNEL); 260 if (!psvts) { 261 result = -ENOMEM; 262 goto end; 263 } 264 265 /* Start index is 1 because the first package is the revision number */ 266 for (i = 1; i < p->package.count; i++) { 267 struct acpi_buffer psvt_int_format = { sizeof("RRNNNNNNNNNN"), "RRNNNNNNNNNN" }; 268 struct acpi_buffer psvt_str_format = { sizeof("RRNNNNNSNNNN"), "RRNNNNNSNNNN" }; 269 union acpi_object *package = &(p->package.elements[i]); 270 struct psvt *psvt = &psvts[i - 1 - nr_bad_entries]; 271 struct acpi_buffer *psvt_format = &psvt_int_format; 272 struct acpi_buffer element = { 0, NULL }; 273 union acpi_object *knob; 274 struct acpi_device *res; 275 struct psvt *psvt_ptr; 276 277 element.length = ACPI_ALLOCATE_BUFFER; 278 element.pointer = NULL; 279 280 if (package->package.count >= ACPI_NR_PSVT_ELEMENTS) { 281 knob = &(package->package.elements[ACPI_PSVT_CONTROL_KNOB]); 282 } else { 283 nr_bad_entries++; 284 pr_info("PSVT package %d is invalid, ignored\n", i); 285 continue; 286 } 287 288 if (knob->type == ACPI_TYPE_STRING) { 289 psvt_format = &psvt_str_format; 290 if (knob->string.length > ACPI_LIMIT_STR_MAX_LEN - 1) { 291 pr_info("PSVT package %d limit string len exceeds max\n", i); 292 knob->string.length = ACPI_LIMIT_STR_MAX_LEN - 1; 293 } 294 } 295 296 status = acpi_extract_package(&(p->package.elements[i]), psvt_format, &element); 297 if (ACPI_FAILURE(status)) { 298 nr_bad_entries++; 299 pr_info("PSVT package %d is invalid, ignored\n", i); 300 continue; 301 } 302 303 psvt_ptr = (struct psvt *)element.pointer; 304 305 memcpy(psvt, psvt_ptr, sizeof(*psvt)); 306 307 /* The limit element can be string or U64 */ 308 psvt->control_knob_type = (u64)knob->type; 309 310 if (knob->type == ACPI_TYPE_STRING) { 311 memset(&psvt->limit, 0, sizeof(u64)); 312 strncpy(psvt->limit.string, psvt_ptr->limit.str_ptr, knob->string.length); 313 } else { 314 psvt->limit.integer = psvt_ptr->limit.integer; 315 } 316 317 kfree(element.pointer); 318 319 res = acpi_fetch_acpi_dev(psvt->source); 320 if (!res) { 321 nr_bad_entries++; 322 pr_info("Failed to get source ACPI device\n"); 323 continue; 324 } 325 326 res = acpi_fetch_acpi_dev(psvt->target); 327 if (!res) { 328 nr_bad_entries++; 329 pr_info("Failed to get target ACPI device\n"); 330 continue; 331 } 332 } 333 334 /* don't count bad entries */ 335 *psvt_count -= nr_bad_entries; 336 337 if (!*psvt_count) { 338 result = -EFAULT; 339 kfree(psvts); 340 goto end; 341 } 342 343 *psvtp = psvts; 344 345 return 0; 346 347end: 348 kfree(buffer.pointer); 349 return result; 350} 351 352/* get device name from acpi handle */ 353static void get_single_name(acpi_handle handle, char *name) 354{ 355 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER}; 356 357 if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer))) 358 pr_warn("Failed to get device name from acpi handle\n"); 359 else { 360 memcpy(name, buffer.pointer, ACPI_NAMESEG_SIZE); 361 kfree(buffer.pointer); 362 } 363} 364 365static int fill_art(char __user *ubuf) 366{ 367 int i; 368 int ret; 369 int count; 370 int art_len; 371 struct art *arts = NULL; 372 union art_object *art_user; 373 374 ret = acpi_parse_art(acpi_thermal_rel_handle, &count, &arts, false); 375 if (ret) 376 goto free_art; 377 art_len = count * sizeof(union art_object); 378 art_user = kzalloc(art_len, GFP_KERNEL); 379 if (!art_user) { 380 ret = -ENOMEM; 381 goto free_art; 382 } 383 /* now fill in user art data */ 384 for (i = 0; i < count; i++) { 385 /* userspace art needs device name instead of acpi reference */ 386 get_single_name(arts[i].source, art_user[i].source_device); 387 get_single_name(arts[i].target, art_user[i].target_device); 388 /* copy the rest int data in addition to source and target */ 389 BUILD_BUG_ON(sizeof(art_user[i].data) != 390 sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2)); 391 memcpy(&art_user[i].data, &arts[i].data, sizeof(art_user[i].data)); 392 } 393 394 if (copy_to_user(ubuf, art_user, art_len)) 395 ret = -EFAULT; 396 kfree(art_user); 397free_art: 398 kfree(arts); 399 return ret; 400} 401 402static int fill_trt(char __user *ubuf) 403{ 404 int i; 405 int ret; 406 int count; 407 int trt_len; 408 struct trt *trts = NULL; 409 union trt_object *trt_user; 410 411 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count, &trts, false); 412 if (ret) 413 goto free_trt; 414 trt_len = count * sizeof(union trt_object); 415 trt_user = kzalloc(trt_len, GFP_KERNEL); 416 if (!trt_user) { 417 ret = -ENOMEM; 418 goto free_trt; 419 } 420 /* now fill in user trt data */ 421 for (i = 0; i < count; i++) { 422 /* userspace trt needs device name instead of acpi reference */ 423 get_single_name(trts[i].source, trt_user[i].source_device); 424 get_single_name(trts[i].target, trt_user[i].target_device); 425 trt_user[i].sample_period = trts[i].sample_period; 426 trt_user[i].influence = trts[i].influence; 427 } 428 429 if (copy_to_user(ubuf, trt_user, trt_len)) 430 ret = -EFAULT; 431 kfree(trt_user); 432free_trt: 433 kfree(trts); 434 return ret; 435} 436 437static int fill_psvt(char __user *ubuf) 438{ 439 int i, ret, count, psvt_len; 440 union psvt_object *psvt_user; 441 struct psvt *psvts; 442 443 ret = acpi_parse_psvt(acpi_thermal_rel_handle, &count, &psvts); 444 if (ret) 445 return ret; 446 447 psvt_len = count * sizeof(*psvt_user); 448 449 psvt_user = kzalloc(psvt_len, GFP_KERNEL); 450 if (!psvt_user) { 451 ret = -ENOMEM; 452 goto free_psvt; 453 } 454 455 /* now fill in user psvt data */ 456 for (i = 0; i < count; i++) { 457 /* userspace psvt needs device name instead of acpi reference */ 458 get_single_name(psvts[i].source, psvt_user[i].source_device); 459 get_single_name(psvts[i].target, psvt_user[i].target_device); 460 461 psvt_user[i].priority = psvts[i].priority; 462 psvt_user[i].sample_period = psvts[i].sample_period; 463 psvt_user[i].passive_temp = psvts[i].passive_temp; 464 psvt_user[i].source_domain = psvts[i].source_domain; 465 psvt_user[i].control_knob = psvts[i].control_knob; 466 psvt_user[i].step_size = psvts[i].step_size; 467 psvt_user[i].limit_coeff = psvts[i].limit_coeff; 468 psvt_user[i].unlimit_coeff = psvts[i].unlimit_coeff; 469 psvt_user[i].control_knob_type = psvts[i].control_knob_type; 470 if (psvt_user[i].control_knob_type == ACPI_TYPE_STRING) 471 strncpy(psvt_user[i].limit.string, psvts[i].limit.string, 472 ACPI_LIMIT_STR_MAX_LEN); 473 else 474 psvt_user[i].limit.integer = psvts[i].limit.integer; 475 476 } 477 478 if (copy_to_user(ubuf, psvt_user, psvt_len)) 479 ret = -EFAULT; 480 481 kfree(psvt_user); 482 483free_psvt: 484 kfree(psvts); 485 return ret; 486} 487 488static long acpi_thermal_rel_ioctl(struct file *f, unsigned int cmd, 489 unsigned long __arg) 490{ 491 int ret = 0; 492 unsigned long length = 0; 493 int count = 0; 494 char __user *arg = (void __user *)__arg; 495 struct trt *trts = NULL; 496 struct art *arts = NULL; 497 struct psvt *psvts; 498 499 switch (cmd) { 500 case ACPI_THERMAL_GET_TRT_COUNT: 501 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count, 502 &trts, false); 503 kfree(trts); 504 if (!ret) 505 return put_user(count, (unsigned long __user *)__arg); 506 return ret; 507 case ACPI_THERMAL_GET_TRT_LEN: 508 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count, 509 &trts, false); 510 kfree(trts); 511 length = count * sizeof(union trt_object); 512 if (!ret) 513 return put_user(length, (unsigned long __user *)__arg); 514 return ret; 515 case ACPI_THERMAL_GET_TRT: 516 return fill_trt(arg); 517 case ACPI_THERMAL_GET_ART_COUNT: 518 ret = acpi_parse_art(acpi_thermal_rel_handle, &count, 519 &arts, false); 520 kfree(arts); 521 if (!ret) 522 return put_user(count, (unsigned long __user *)__arg); 523 return ret; 524 case ACPI_THERMAL_GET_ART_LEN: 525 ret = acpi_parse_art(acpi_thermal_rel_handle, &count, 526 &arts, false); 527 kfree(arts); 528 length = count * sizeof(union art_object); 529 if (!ret) 530 return put_user(length, (unsigned long __user *)__arg); 531 return ret; 532 533 case ACPI_THERMAL_GET_ART: 534 return fill_art(arg); 535 536 case ACPI_THERMAL_GET_PSVT_COUNT: 537 ret = acpi_parse_psvt(acpi_thermal_rel_handle, &count, &psvts); 538 if (!ret) { 539 kfree(psvts); 540 return put_user(count, (unsigned long __user *)__arg); 541 } 542 return ret; 543 544 case ACPI_THERMAL_GET_PSVT_LEN: 545 /* total length of the data retrieved (count * PSVT entry size) */ 546 ret = acpi_parse_psvt(acpi_thermal_rel_handle, &count, &psvts); 547 length = count * sizeof(union psvt_object); 548 if (!ret) { 549 kfree(psvts); 550 return put_user(length, (unsigned long __user *)__arg); 551 } 552 return ret; 553 554 case ACPI_THERMAL_GET_PSVT: 555 return fill_psvt(arg); 556 557 default: 558 return -ENOTTY; 559 } 560} 561 562static const struct file_operations acpi_thermal_rel_fops = { 563 .owner = THIS_MODULE, 564 .open = acpi_thermal_rel_open, 565 .release = acpi_thermal_rel_release, 566 .unlocked_ioctl = acpi_thermal_rel_ioctl, 567 .llseek = no_llseek, 568}; 569 570static struct miscdevice acpi_thermal_rel_misc_device = { 571 .minor = MISC_DYNAMIC_MINOR, 572 "acpi_thermal_rel", 573 &acpi_thermal_rel_fops 574}; 575 576int acpi_thermal_rel_misc_device_add(acpi_handle handle) 577{ 578 acpi_thermal_rel_handle = handle; 579 580 return misc_register(&acpi_thermal_rel_misc_device); 581} 582EXPORT_SYMBOL(acpi_thermal_rel_misc_device_add); 583 584int acpi_thermal_rel_misc_device_remove(acpi_handle handle) 585{ 586 misc_deregister(&acpi_thermal_rel_misc_device); 587 588 return 0; 589} 590EXPORT_SYMBOL(acpi_thermal_rel_misc_device_remove); 591 592MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 593MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com"); 594MODULE_DESCRIPTION("Intel acpi thermal rel misc dev driver"); 595MODULE_LICENSE("GPL v2"); 596