1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * acpi_utils.c - ACPI Utility Functions ($Revision: 10 $) 4 * 5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 7 */ 8 9#include <linux/kernel.h> 10#include <linux/module.h> 11#include <linux/slab.h> 12#include <linux/init.h> 13#include <linux/types.h> 14#include <linux/hardirq.h> 15#include <linux/acpi.h> 16#include <linux/dynamic_debug.h> 17 18#include "internal.h" 19#include "sleep.h" 20 21#define _COMPONENT ACPI_BUS_COMPONENT 22ACPI_MODULE_NAME("utils"); 23 24/* -------------------------------------------------------------------------- 25 Object Evaluation Helpers 26 -------------------------------------------------------------------------- */ 27static void 28acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s) 29{ 30#ifdef ACPI_DEBUG_OUTPUT 31 char prefix[80] = {'\0'}; 32 struct acpi_buffer buffer = {sizeof(prefix), prefix}; 33 acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer); 34 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n", 35 (char *) prefix, p, acpi_format_exception(s))); 36#else 37 return; 38#endif 39} 40 41acpi_status 42acpi_extract_package(union acpi_object *package, 43 struct acpi_buffer *format, struct acpi_buffer *buffer) 44{ 45 u32 size_required = 0; 46 u32 tail_offset = 0; 47 char *format_string = NULL; 48 u32 format_count = 0; 49 u32 i = 0; 50 u8 *head = NULL; 51 u8 *tail = NULL; 52 53 54 if (!package || (package->type != ACPI_TYPE_PACKAGE) 55 || (package->package.count < 1)) { 56 printk(KERN_WARNING PREFIX "Invalid package argument\n"); 57 return AE_BAD_PARAMETER; 58 } 59 60 if (!format || !format->pointer || (format->length < 1)) { 61 printk(KERN_WARNING PREFIX "Invalid format argument\n"); 62 return AE_BAD_PARAMETER; 63 } 64 65 if (!buffer) { 66 printk(KERN_WARNING PREFIX "Invalid buffer argument\n"); 67 return AE_BAD_PARAMETER; 68 } 69 70 format_count = (format->length / sizeof(char)) - 1; 71 if (format_count > package->package.count) { 72 printk(KERN_WARNING PREFIX "Format specifies more objects [%d]" 73 " than exist in package [%d].\n", 74 format_count, package->package.count); 75 return AE_BAD_DATA; 76 } 77 78 format_string = format->pointer; 79 80 /* 81 * Calculate size_required. 82 */ 83 for (i = 0; i < format_count; i++) { 84 85 union acpi_object *element = &(package->package.elements[i]); 86 87 switch (element->type) { 88 89 case ACPI_TYPE_INTEGER: 90 switch (format_string[i]) { 91 case 'N': 92 size_required += sizeof(u64); 93 tail_offset += sizeof(u64); 94 break; 95 case 'S': 96 size_required += 97 sizeof(char *) + sizeof(u64) + 98 sizeof(char); 99 tail_offset += sizeof(char *); 100 break; 101 default: 102 printk(KERN_WARNING PREFIX "Invalid package element" 103 " [%d]: got number, expecting" 104 " [%c]\n", 105 i, format_string[i]); 106 return AE_BAD_DATA; 107 } 108 break; 109 110 case ACPI_TYPE_STRING: 111 case ACPI_TYPE_BUFFER: 112 switch (format_string[i]) { 113 case 'S': 114 size_required += 115 sizeof(char *) + 116 (element->string.length * sizeof(char)) + 117 sizeof(char); 118 tail_offset += sizeof(char *); 119 break; 120 case 'B': 121 size_required += 122 sizeof(u8 *) + element->buffer.length; 123 tail_offset += sizeof(u8 *); 124 break; 125 default: 126 printk(KERN_WARNING PREFIX "Invalid package element" 127 " [%d] got string/buffer," 128 " expecting [%c]\n", 129 i, format_string[i]); 130 return AE_BAD_DATA; 131 } 132 break; 133 case ACPI_TYPE_LOCAL_REFERENCE: 134 switch (format_string[i]) { 135 case 'R': 136 size_required += sizeof(void *); 137 tail_offset += sizeof(void *); 138 break; 139 default: 140 printk(KERN_WARNING PREFIX "Invalid package element" 141 " [%d] got reference," 142 " expecting [%c]\n", 143 i, format_string[i]); 144 return AE_BAD_DATA; 145 } 146 break; 147 148 case ACPI_TYPE_PACKAGE: 149 default: 150 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 151 "Found unsupported element at index=%d\n", 152 i)); 153 /* TBD: handle nested packages... */ 154 return AE_SUPPORT; 155 } 156 } 157 158 /* 159 * Validate output buffer. 160 */ 161 if (buffer->length == ACPI_ALLOCATE_BUFFER) { 162 buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required); 163 if (!buffer->pointer) 164 return AE_NO_MEMORY; 165 buffer->length = size_required; 166 } else { 167 if (buffer->length < size_required) { 168 buffer->length = size_required; 169 return AE_BUFFER_OVERFLOW; 170 } else if (buffer->length != size_required || 171 !buffer->pointer) { 172 return AE_BAD_PARAMETER; 173 } 174 } 175 176 head = buffer->pointer; 177 tail = buffer->pointer + tail_offset; 178 179 /* 180 * Extract package data. 181 */ 182 for (i = 0; i < format_count; i++) { 183 184 u8 **pointer = NULL; 185 union acpi_object *element = &(package->package.elements[i]); 186 187 switch (element->type) { 188 189 case ACPI_TYPE_INTEGER: 190 switch (format_string[i]) { 191 case 'N': 192 *((u64 *) head) = 193 element->integer.value; 194 head += sizeof(u64); 195 break; 196 case 'S': 197 pointer = (u8 **) head; 198 *pointer = tail; 199 *((u64 *) tail) = 200 element->integer.value; 201 head += sizeof(u64 *); 202 tail += sizeof(u64); 203 /* NULL terminate string */ 204 *tail = (char)0; 205 tail += sizeof(char); 206 break; 207 default: 208 /* Should never get here */ 209 break; 210 } 211 break; 212 213 case ACPI_TYPE_STRING: 214 case ACPI_TYPE_BUFFER: 215 switch (format_string[i]) { 216 case 'S': 217 pointer = (u8 **) head; 218 *pointer = tail; 219 memcpy(tail, element->string.pointer, 220 element->string.length); 221 head += sizeof(char *); 222 tail += element->string.length * sizeof(char); 223 /* NULL terminate string */ 224 *tail = (char)0; 225 tail += sizeof(char); 226 break; 227 case 'B': 228 pointer = (u8 **) head; 229 *pointer = tail; 230 memcpy(tail, element->buffer.pointer, 231 element->buffer.length); 232 head += sizeof(u8 *); 233 tail += element->buffer.length; 234 break; 235 default: 236 /* Should never get here */ 237 break; 238 } 239 break; 240 case ACPI_TYPE_LOCAL_REFERENCE: 241 switch (format_string[i]) { 242 case 'R': 243 *(void **)head = 244 (void *)element->reference.handle; 245 head += sizeof(void *); 246 break; 247 default: 248 /* Should never get here */ 249 break; 250 } 251 break; 252 case ACPI_TYPE_PACKAGE: 253 /* TBD: handle nested packages... */ 254 default: 255 /* Should never get here */ 256 break; 257 } 258 } 259 260 return AE_OK; 261} 262 263EXPORT_SYMBOL(acpi_extract_package); 264 265acpi_status 266acpi_evaluate_integer(acpi_handle handle, 267 acpi_string pathname, 268 struct acpi_object_list *arguments, unsigned long long *data) 269{ 270 acpi_status status = AE_OK; 271 union acpi_object element; 272 struct acpi_buffer buffer = { 0, NULL }; 273 274 if (!data) 275 return AE_BAD_PARAMETER; 276 277 buffer.length = sizeof(union acpi_object); 278 buffer.pointer = &element; 279 status = acpi_evaluate_object(handle, pathname, arguments, &buffer); 280 if (ACPI_FAILURE(status)) { 281 acpi_util_eval_error(handle, pathname, status); 282 return status; 283 } 284 285 if (element.type != ACPI_TYPE_INTEGER) { 286 acpi_util_eval_error(handle, pathname, AE_BAD_DATA); 287 return AE_BAD_DATA; 288 } 289 290 *data = element.integer.value; 291 292 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data)); 293 294 return AE_OK; 295} 296 297EXPORT_SYMBOL(acpi_evaluate_integer); 298 299acpi_status 300acpi_evaluate_reference(acpi_handle handle, 301 acpi_string pathname, 302 struct acpi_object_list *arguments, 303 struct acpi_handle_list *list) 304{ 305 acpi_status status = AE_OK; 306 union acpi_object *package = NULL; 307 union acpi_object *element = NULL; 308 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 309 u32 i = 0; 310 311 312 if (!list) { 313 return AE_BAD_PARAMETER; 314 } 315 316 /* Evaluate object. */ 317 318 status = acpi_evaluate_object(handle, pathname, arguments, &buffer); 319 if (ACPI_FAILURE(status)) 320 goto end; 321 322 package = buffer.pointer; 323 324 if ((buffer.length == 0) || !package) { 325 status = AE_BAD_DATA; 326 acpi_util_eval_error(handle, pathname, status); 327 goto end; 328 } 329 if (package->type != ACPI_TYPE_PACKAGE) { 330 status = AE_BAD_DATA; 331 acpi_util_eval_error(handle, pathname, status); 332 goto end; 333 } 334 if (!package->package.count) { 335 status = AE_BAD_DATA; 336 acpi_util_eval_error(handle, pathname, status); 337 goto end; 338 } 339 340 if (package->package.count > ACPI_MAX_HANDLES) { 341 kfree(package); 342 return AE_NO_MEMORY; 343 } 344 list->count = package->package.count; 345 346 /* Extract package data. */ 347 348 for (i = 0; i < list->count; i++) { 349 350 element = &(package->package.elements[i]); 351 352 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) { 353 status = AE_BAD_DATA; 354 acpi_util_eval_error(handle, pathname, status); 355 break; 356 } 357 358 if (!element->reference.handle) { 359 status = AE_NULL_ENTRY; 360 acpi_util_eval_error(handle, pathname, status); 361 break; 362 } 363 /* Get the acpi_handle. */ 364 365 list->handles[i] = element->reference.handle; 366 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n", 367 list->handles[i])); 368 } 369 370 end: 371 if (ACPI_FAILURE(status)) { 372 list->count = 0; 373 //kfree(list->handles); 374 } 375 376 kfree(buffer.pointer); 377 378 return status; 379} 380 381EXPORT_SYMBOL(acpi_evaluate_reference); 382 383acpi_status 384acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld) 385{ 386 acpi_status status; 387 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 388 union acpi_object *output; 389 390 status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer); 391 392 if (ACPI_FAILURE(status)) 393 return status; 394 395 output = buffer.pointer; 396 397 if (!output || output->type != ACPI_TYPE_PACKAGE 398 || !output->package.count 399 || output->package.elements[0].type != ACPI_TYPE_BUFFER 400 || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) { 401 status = AE_TYPE; 402 goto out; 403 } 404 405 status = acpi_decode_pld_buffer( 406 output->package.elements[0].buffer.pointer, 407 output->package.elements[0].buffer.length, 408 pld); 409 410out: 411 kfree(buffer.pointer); 412 return status; 413} 414EXPORT_SYMBOL(acpi_get_physical_device_location); 415 416/** 417 * acpi_evaluate_ost: Evaluate _OST for hotplug operations 418 * @handle: ACPI device handle 419 * @source_event: source event code 420 * @status_code: status code 421 * @status_buf: optional detailed information (NULL if none) 422 * 423 * Evaluate _OST for hotplug operations. All ACPI hotplug handlers 424 * must call this function when evaluating _OST for hotplug operations. 425 * When the platform does not support _OST, this function has no effect. 426 */ 427acpi_status 428acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code, 429 struct acpi_buffer *status_buf) 430{ 431 union acpi_object params[3] = { 432 {.type = ACPI_TYPE_INTEGER,}, 433 {.type = ACPI_TYPE_INTEGER,}, 434 {.type = ACPI_TYPE_BUFFER,} 435 }; 436 struct acpi_object_list arg_list = {3, params}; 437 438 params[0].integer.value = source_event; 439 params[1].integer.value = status_code; 440 if (status_buf != NULL) { 441 params[2].buffer.pointer = status_buf->pointer; 442 params[2].buffer.length = status_buf->length; 443 } else { 444 params[2].buffer.pointer = NULL; 445 params[2].buffer.length = 0; 446 } 447 448 return acpi_evaluate_object(handle, "_OST", &arg_list, NULL); 449} 450EXPORT_SYMBOL(acpi_evaluate_ost); 451 452/** 453 * acpi_handle_path: Return the object path of handle 454 * @handle: ACPI device handle 455 * 456 * Caller must free the returned buffer 457 */ 458static char *acpi_handle_path(acpi_handle handle) 459{ 460 struct acpi_buffer buffer = { 461 .length = ACPI_ALLOCATE_BUFFER, 462 .pointer = NULL 463 }; 464 465 if (in_interrupt() || 466 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK) 467 return NULL; 468 return buffer.pointer; 469} 470 471/** 472 * acpi_handle_printk: Print message with ACPI prefix and object path 473 * @level: log level 474 * @handle: ACPI device handle 475 * @fmt: format string 476 * 477 * This function is called through acpi_handle_<level> macros and prints 478 * a message with ACPI prefix and object path. This function acquires 479 * the global namespace mutex to obtain an object path. In interrupt 480 * context, it shows the object path as <n/a>. 481 */ 482void 483acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...) 484{ 485 struct va_format vaf; 486 va_list args; 487 const char *path; 488 489 va_start(args, fmt); 490 vaf.fmt = fmt; 491 vaf.va = &args; 492 493 path = acpi_handle_path(handle); 494 printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf); 495 496 va_end(args); 497 kfree(path); 498} 499EXPORT_SYMBOL(acpi_handle_printk); 500 501#if defined(CONFIG_DYNAMIC_DEBUG) 502/** 503 * __acpi_handle_debug: pr_debug with ACPI prefix and object path 504 * @descriptor: Dynamic Debug descriptor 505 * @handle: ACPI device handle 506 * @fmt: format string 507 * 508 * This function is called through acpi_handle_debug macro and debug 509 * prints a message with ACPI prefix and object path. This function 510 * acquires the global namespace mutex to obtain an object path. In 511 * interrupt context, it shows the object path as <n/a>. 512 */ 513void 514__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle, 515 const char *fmt, ...) 516{ 517 struct va_format vaf; 518 va_list args; 519 const char *path; 520 521 va_start(args, fmt); 522 vaf.fmt = fmt; 523 vaf.va = &args; 524 525 path = acpi_handle_path(handle); 526 __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf); 527 528 va_end(args); 529 kfree(path); 530} 531EXPORT_SYMBOL(__acpi_handle_debug); 532#endif 533 534/** 535 * acpi_has_method: Check whether @handle has a method named @name 536 * @handle: ACPI device handle 537 * @name: name of object or method 538 * 539 * Check whether @handle has a method named @name. 540 */ 541bool acpi_has_method(acpi_handle handle, char *name) 542{ 543 acpi_handle tmp; 544 545 return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp)); 546} 547EXPORT_SYMBOL(acpi_has_method); 548 549acpi_status acpi_execute_simple_method(acpi_handle handle, char *method, 550 u64 arg) 551{ 552 union acpi_object obj = { .type = ACPI_TYPE_INTEGER }; 553 struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, }; 554 555 obj.integer.value = arg; 556 557 return acpi_evaluate_object(handle, method, &arg_list, NULL); 558} 559EXPORT_SYMBOL(acpi_execute_simple_method); 560 561/** 562 * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations 563 * @handle: ACPI device handle 564 * 565 * Evaluate device's _EJ0 method for hotplug operations. 566 */ 567acpi_status acpi_evaluate_ej0(acpi_handle handle) 568{ 569 acpi_status status; 570 571 status = acpi_execute_simple_method(handle, "_EJ0", 1); 572 if (status == AE_NOT_FOUND) 573 acpi_handle_warn(handle, "No _EJ0 support for device\n"); 574 else if (ACPI_FAILURE(status)) 575 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status); 576 577 return status; 578} 579 580/** 581 * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device 582 * @handle: ACPI device handle 583 * @lock: lock device if non-zero, otherwise unlock device 584 * 585 * Evaluate device's _LCK method if present to lock/unlock device 586 */ 587acpi_status acpi_evaluate_lck(acpi_handle handle, int lock) 588{ 589 acpi_status status; 590 591 status = acpi_execute_simple_method(handle, "_LCK", !!lock); 592 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { 593 if (lock) 594 acpi_handle_warn(handle, 595 "Locking device failed (0x%x)\n", status); 596 else 597 acpi_handle_warn(handle, 598 "Unlocking device failed (0x%x)\n", status); 599 } 600 601 return status; 602} 603 604/** 605 * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence 606 * @handle: ACPI device handle 607 * @space_id: ACPI address space id to register OpRegion presence for 608 * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or 609 * ACPI_REG_DISCONNECT 610 * 611 * Evaluate device's _REG method to register OpRegion presence. 612 */ 613acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function) 614{ 615 struct acpi_object_list arg_list; 616 union acpi_object params[2]; 617 618 params[0].type = ACPI_TYPE_INTEGER; 619 params[0].integer.value = space_id; 620 params[1].type = ACPI_TYPE_INTEGER; 621 params[1].integer.value = function; 622 arg_list.count = 2; 623 arg_list.pointer = params; 624 625 return acpi_evaluate_object(handle, "_REG", &arg_list, NULL); 626} 627EXPORT_SYMBOL(acpi_evaluate_reg); 628 629/** 630 * acpi_evaluate_dsm - evaluate device's _DSM method 631 * @handle: ACPI device handle 632 * @guid: GUID of requested functions, should be 16 bytes 633 * @rev: revision number of requested function 634 * @func: requested function number 635 * @argv4: the function specific parameter 636 * 637 * Evaluate device's _DSM method with specified GUID, revision id and 638 * function number. Caller needs to free the returned object. 639 * 640 * Though ACPI defines the fourth parameter for _DSM should be a package, 641 * some old BIOSes do expect a buffer or an integer etc. 642 */ 643union acpi_object * 644acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func, 645 union acpi_object *argv4) 646{ 647 acpi_status ret; 648 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL}; 649 union acpi_object params[4]; 650 struct acpi_object_list input = { 651 .count = 4, 652 .pointer = params, 653 }; 654 655 params[0].type = ACPI_TYPE_BUFFER; 656 params[0].buffer.length = 16; 657 params[0].buffer.pointer = (u8 *)guid; 658 params[1].type = ACPI_TYPE_INTEGER; 659 params[1].integer.value = rev; 660 params[2].type = ACPI_TYPE_INTEGER; 661 params[2].integer.value = func; 662 if (argv4) { 663 params[3] = *argv4; 664 } else { 665 params[3].type = ACPI_TYPE_PACKAGE; 666 params[3].package.count = 0; 667 params[3].package.elements = NULL; 668 } 669 670 ret = acpi_evaluate_object(handle, "_DSM", &input, &buf); 671 if (ACPI_SUCCESS(ret)) 672 return (union acpi_object *)buf.pointer; 673 674 if (ret != AE_NOT_FOUND) 675 acpi_handle_warn(handle, 676 "failed to evaluate _DSM (0x%x)\n", ret); 677 678 return NULL; 679} 680EXPORT_SYMBOL(acpi_evaluate_dsm); 681 682/** 683 * acpi_check_dsm - check if _DSM method supports requested functions. 684 * @handle: ACPI device handle 685 * @guid: GUID of requested functions, should be 16 bytes at least 686 * @rev: revision number of requested functions 687 * @funcs: bitmap of requested functions 688 * 689 * Evaluate device's _DSM method to check whether it supports requested 690 * functions. Currently only support 64 functions at maximum, should be 691 * enough for now. 692 */ 693bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs) 694{ 695 int i; 696 u64 mask = 0; 697 union acpi_object *obj; 698 699 if (funcs == 0) 700 return false; 701 702 obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL); 703 if (!obj) 704 return false; 705 706 /* For compatibility, old BIOSes may return an integer */ 707 if (obj->type == ACPI_TYPE_INTEGER) 708 mask = obj->integer.value; 709 else if (obj->type == ACPI_TYPE_BUFFER) 710 for (i = 0; i < obj->buffer.length && i < 8; i++) 711 mask |= (((u64)obj->buffer.pointer[i]) << (i * 8)); 712 ACPI_FREE(obj); 713 714 /* 715 * Bit 0 indicates whether there's support for any functions other than 716 * function 0 for the specified GUID and revision. 717 */ 718 if ((mask & 0x1) && (mask & funcs) == funcs) 719 return true; 720 721 return false; 722} 723EXPORT_SYMBOL(acpi_check_dsm); 724 725/** 726 * acpi_dev_hid_uid_match - Match device by supplied HID and UID 727 * @adev: ACPI device to match. 728 * @hid2: Hardware ID of the device. 729 * @uid2: Unique ID of the device, pass NULL to not check _UID. 730 * 731 * Matches HID and UID in @adev with given @hid2 and @uid2. 732 * Returns true if matches. 733 */ 734bool acpi_dev_hid_uid_match(struct acpi_device *adev, 735 const char *hid2, const char *uid2) 736{ 737 const char *hid1 = acpi_device_hid(adev); 738 const char *uid1 = acpi_device_uid(adev); 739 740 if (strcmp(hid1, hid2)) 741 return false; 742 743 if (!uid2) 744 return true; 745 746 return uid1 && !strcmp(uid1, uid2); 747} 748EXPORT_SYMBOL(acpi_dev_hid_uid_match); 749 750/** 751 * acpi_dev_found - Detect presence of a given ACPI device in the namespace. 752 * @hid: Hardware ID of the device. 753 * 754 * Return %true if the device was present at the moment of invocation. 755 * Note that if the device is pluggable, it may since have disappeared. 756 * 757 * For this function to work, acpi_bus_scan() must have been executed 758 * which happens in the subsys_initcall() subsection. Hence, do not 759 * call from a subsys_initcall() or earlier (use acpi_get_devices() 760 * instead). Calling from module_init() is fine (which is synonymous 761 * with device_initcall()). 762 */ 763bool acpi_dev_found(const char *hid) 764{ 765 struct acpi_device_bus_id *acpi_device_bus_id; 766 bool found = false; 767 768 mutex_lock(&acpi_device_lock); 769 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) 770 if (!strcmp(acpi_device_bus_id->bus_id, hid)) { 771 found = true; 772 break; 773 } 774 mutex_unlock(&acpi_device_lock); 775 776 return found; 777} 778EXPORT_SYMBOL(acpi_dev_found); 779 780struct acpi_dev_match_info { 781 struct acpi_device_id hid[2]; 782 const char *uid; 783 s64 hrv; 784}; 785 786static int acpi_dev_match_cb(struct device *dev, const void *data) 787{ 788 struct acpi_device *adev = to_acpi_device(dev); 789 const struct acpi_dev_match_info *match = data; 790 unsigned long long hrv; 791 acpi_status status; 792 793 if (acpi_match_device_ids(adev, match->hid)) 794 return 0; 795 796 if (match->uid && (!adev->pnp.unique_id || 797 strcmp(adev->pnp.unique_id, match->uid))) 798 return 0; 799 800 if (match->hrv == -1) 801 return 1; 802 803 status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv); 804 if (ACPI_FAILURE(status)) 805 return 0; 806 807 return hrv == match->hrv; 808} 809 810/** 811 * acpi_dev_present - Detect that a given ACPI device is present 812 * @hid: Hardware ID of the device. 813 * @uid: Unique ID of the device, pass NULL to not check _UID 814 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV 815 * 816 * Return %true if a matching device was present at the moment of invocation. 817 * Note that if the device is pluggable, it may since have disappeared. 818 * 819 * Note that unlike acpi_dev_found() this function checks the status 820 * of the device. So for devices which are present in the dsdt, but 821 * which are disabled (their _STA callback returns 0) this function 822 * will return false. 823 * 824 * For this function to work, acpi_bus_scan() must have been executed 825 * which happens in the subsys_initcall() subsection. Hence, do not 826 * call from a subsys_initcall() or earlier (use acpi_get_devices() 827 * instead). Calling from module_init() is fine (which is synonymous 828 * with device_initcall()). 829 */ 830bool acpi_dev_present(const char *hid, const char *uid, s64 hrv) 831{ 832 struct acpi_dev_match_info match = {}; 833 struct device *dev; 834 835 strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id)); 836 match.uid = uid; 837 match.hrv = hrv; 838 839 dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb); 840 put_device(dev); 841 return !!dev; 842} 843EXPORT_SYMBOL(acpi_dev_present); 844 845/** 846 * acpi_dev_get_first_match_dev - Return the first match of ACPI device 847 * @hid: Hardware ID of the device. 848 * @uid: Unique ID of the device, pass NULL to not check _UID 849 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV 850 * 851 * Return the first match of ACPI device if a matching device was present 852 * at the moment of invocation, or NULL otherwise. 853 * 854 * The caller is responsible to call put_device() on the returned device. 855 * 856 * See additional information in acpi_dev_present() as well. 857 */ 858struct acpi_device * 859acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv) 860{ 861 struct acpi_dev_match_info match = {}; 862 struct device *dev; 863 864 strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id)); 865 match.uid = uid; 866 match.hrv = hrv; 867 868 dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb); 869 return dev ? to_acpi_device(dev) : NULL; 870} 871EXPORT_SYMBOL(acpi_dev_get_first_match_dev); 872 873/* 874 * acpi_backlight= handling, this is done here rather then in video_detect.c 875 * because __setup cannot be used in modules. 876 */ 877char acpi_video_backlight_string[16]; 878EXPORT_SYMBOL(acpi_video_backlight_string); 879 880static int __init acpi_backlight(char *str) 881{ 882 strlcpy(acpi_video_backlight_string, str, 883 sizeof(acpi_video_backlight_string)); 884 return 1; 885} 886__setup("acpi_backlight=", acpi_backlight); 887 888/** 889 * acpi_match_platform_list - Check if the system matches with a given list 890 * @plat: pointer to acpi_platform_list table terminated by a NULL entry 891 * 892 * Return the matched index if the system is found in the platform list. 893 * Otherwise, return a negative error code. 894 */ 895int acpi_match_platform_list(const struct acpi_platform_list *plat) 896{ 897 struct acpi_table_header hdr; 898 int idx = 0; 899 900 if (acpi_disabled) 901 return -ENODEV; 902 903 for (; plat->oem_id[0]; plat++, idx++) { 904 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr))) 905 continue; 906 907 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE)) 908 continue; 909 910 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE)) 911 continue; 912 913 if ((plat->pred == all_versions) || 914 (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) || 915 (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) || 916 (plat->pred == equal && hdr.oem_revision == plat->oem_revision)) 917 return idx; 918 } 919 920 return -ENODEV; 921} 922EXPORT_SYMBOL(acpi_match_platform_list); 923