drivers/acpi/utils.c

   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 #define pr_fmt(fmt) "ACPI: utils: " fmt
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/hardirq.h>
  17 #include <linux/acpi.h>
  18 #include <linux/dynamic_debug.h>
  19
  20 #include "internal.h"
  21 #include "sleep.h"
  22
  23 /* --------------------------------------------------------------------------
  24                             Object Evaluation Helpers
  25    -------------------------------------------------------------------------- */
  26 static void acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
  27 {
  28         acpi_handle_debug(h, "Evaluate [%s]: %s\n", p, acpi_format_exception(s));
  29 }
  30
  31 acpi_status
  32 acpi_extract_package(union acpi_object *package,
  33                      struct acpi_buffer *format, struct acpi_buffer *buffer)
  34 {
  35         u32 size_required = 0;
  36         u32 tail_offset = 0;
  37         char *format_string = NULL;
  38         u32 format_count = 0;
  39         u32 i = 0;
  40         u8 *head = NULL;
  41         u8 *tail = NULL;
  42
  43
  44         if (!package || (package->type != ACPI_TYPE_PACKAGE)
  45             || (package->package.count < 1)) {
  46                 pr_debug("Invalid package argument\n");
  47                 return AE_BAD_PARAMETER;
  48         }
  49
  50         if (!format || !format->pointer || (format->length < 1)) {
  51                 pr_debug("Invalid format argument\n");
  52                 return AE_BAD_PARAMETER;
  53         }
  54
  55         if (!buffer) {
  56                 pr_debug("Invalid buffer argument\n");
  57                 return AE_BAD_PARAMETER;
  58         }
  59
  60         format_count = (format->length / sizeof(char)) - 1;
  61         if (format_count > package->package.count) {
  62                 pr_debug("Format specifies more objects [%d] than present [%d]\n",
  63                          format_count, package->package.count);
  64                 return AE_BAD_DATA;
  65         }
  66
  67         format_string = format->pointer;
  68
  69         /*
  70          * Calculate size_required.
  71          */
  72         for (i = 0; i < format_count; i++) {
  73
  74                 union acpi_object *element = &(package->package.elements[i]);
  75
  76                 switch (element->type) {
  77
  78                 case ACPI_TYPE_INTEGER:
  79                         switch (format_string[i]) {
  80                         case 'N':
  81                                 size_required += sizeof(u64);
  82                                 tail_offset += sizeof(u64);
  83                                 break;
  84                         case 'S':
  85                                 size_required +=
  86                                     sizeof(char *) + sizeof(u64) +
  87                                     sizeof(char);
  88                                 tail_offset += sizeof(char *);
  89                                 break;
  90                         default:
  91                                 pr_debug("Invalid package element [%d]: got number, expected [%c]\n",
  92                                          i, format_string[i]);
  93                                 return AE_BAD_DATA;
  94                         }
  95                         break;
  96
  97                 case ACPI_TYPE_STRING:
  98                 case ACPI_TYPE_BUFFER:
  99                         switch (format_string[i]) {
 100                         case 'S':
 101                                 size_required +=
 102                                     sizeof(char *) +
 103                                     (element->string.length * sizeof(char)) +
 104                                     sizeof(char);
 105                                 tail_offset += sizeof(char *);
 106                                 break;
 107                         case 'B':
 108                                 size_required +=
 109                                     sizeof(u8 *) + element->buffer.length;
 110                                 tail_offset += sizeof(u8 *);
 111                                 break;
 112                         default:
 113                                 pr_debug("Invalid package element [%d] got string/buffer, expected [%c]\n",
 114                                          i, format_string[i]);
 115                                 return AE_BAD_DATA;
 116                         }
 117                         break;
 118                 case ACPI_TYPE_LOCAL_REFERENCE:
 119                         switch (format_string[i]) {
 120                         case 'R':
 121                                 size_required += sizeof(void *);
 122                                 tail_offset += sizeof(void *);
 123                                 break;
 124                         default:
 125                                 pr_debug("Invalid package element [%d] got reference, expected [%c]\n",
 126                                          i, format_string[i]);
 127                                 return AE_BAD_DATA;
 128                         }
 129                         break;
 130
 131                 case ACPI_TYPE_PACKAGE:
 132                 default:
 133                         pr_debug("Unsupported element at index=%d\n", i);
 134                         /* TBD: handle nested packages... */
 135                         return AE_SUPPORT;
 136                 }
 137         }
 138
 139         /*
 140          * Validate output buffer.
 141          */
 142         if (buffer->length == ACPI_ALLOCATE_BUFFER) {
 143                 buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
 144                 if (!buffer->pointer)
 145                         return AE_NO_MEMORY;
 146                 buffer->length = size_required;
 147         } else {
 148                 if (buffer->length < size_required) {
 149                         buffer->length = size_required;
 150                         return AE_BUFFER_OVERFLOW;
 151                 } else if (buffer->length != size_required ||
 152                            !buffer->pointer) {
 153                         return AE_BAD_PARAMETER;
 154                 }
 155         }
 156
 157         head = buffer->pointer;
 158         tail = buffer->pointer + tail_offset;
 159
 160         /*
 161          * Extract package data.
 162          */
 163         for (i = 0; i < format_count; i++) {
 164
 165                 u8 **pointer = NULL;
 166                 union acpi_object *element = &(package->package.elements[i]);
 167
 168                 switch (element->type) {
 169
 170                 case ACPI_TYPE_INTEGER:
 171                         switch (format_string[i]) {
 172                         case 'N':
 173                                 *((u64 *) head) =
 174                                     element->integer.value;
 175                                 head += sizeof(u64);
 176                                 break;
 177                         case 'S':
 178                                 pointer = (u8 **) head;
 179                                 *pointer = tail;
 180                                 *((u64 *) tail) =
 181                                     element->integer.value;
 182                                 head += sizeof(u64 *);
 183                                 tail += sizeof(u64);
 184                                 /* NULL terminate string */
 185                                 *tail = (char)0;
 186                                 tail += sizeof(char);
 187                                 break;
 188                         default:
 189                                 /* Should never get here */
 190                                 break;
 191                         }
 192                         break;
 193
 194                 case ACPI_TYPE_STRING:
 195                 case ACPI_TYPE_BUFFER:
 196                         switch (format_string[i]) {
 197                         case 'S':
 198                                 pointer = (u8 **) head;
 199                                 *pointer = tail;
 200                                 memcpy(tail, element->string.pointer,
 201                                        element->string.length);
 202                                 head += sizeof(char *);
 203                                 tail += element->string.length * sizeof(char);
 204                                 /* NULL terminate string */
 205                                 *tail = (char)0;
 206                                 tail += sizeof(char);
 207                                 break;
 208                         case 'B':
 209                                 pointer = (u8 **) head;
 210                                 *pointer = tail;
 211                                 memcpy(tail, element->buffer.pointer,
 212                                        element->buffer.length);
 213                                 head += sizeof(u8 *);
 214                                 tail += element->buffer.length;
 215                                 break;
 216                         default:
 217                                 /* Should never get here */
 218                                 break;
 219                         }
 220                         break;
 221                 case ACPI_TYPE_LOCAL_REFERENCE:
 222                         switch (format_string[i]) {
 223                         case 'R':
 224                                 *(void **)head =
 225                                     (void *)element->reference.handle;
 226                                 head += sizeof(void *);
 227                                 break;
 228                         default:
 229                                 /* Should never get here */
 230                                 break;
 231                         }
 232                         break;
 233                 case ACPI_TYPE_PACKAGE:
 234                         /* TBD: handle nested packages... */
 235                 default:
 236                         /* Should never get here */
 237                         break;
 238                 }
 239         }
 240
 241         return AE_OK;
 242 }
 243
 244 EXPORT_SYMBOL(acpi_extract_package);
 245
 246 acpi_status
 247 acpi_evaluate_integer(acpi_handle handle,
 248                       acpi_string pathname,
 249                       struct acpi_object_list *arguments, unsigned long long *data)
 250 {
 251         acpi_status status = AE_OK;
 252         union acpi_object element;
 253         struct acpi_buffer buffer = { 0, NULL };
 254
 255         if (!data)
 256                 return AE_BAD_PARAMETER;
 257
 258         buffer.length = sizeof(union acpi_object);
 259         buffer.pointer = &element;
 260         status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
 261         if (ACPI_FAILURE(status)) {
 262                 acpi_util_eval_error(handle, pathname, status);
 263                 return status;
 264         }
 265
 266         if (element.type != ACPI_TYPE_INTEGER) {
 267                 acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
 268                 return AE_BAD_DATA;
 269         }
 270
 271         *data = element.integer.value;
 272
 273         acpi_handle_debug(handle, "Return value [%llu]\n", *data);
 274
 275         return AE_OK;
 276 }
 277
 278 EXPORT_SYMBOL(acpi_evaluate_integer);
 279
 280 int acpi_get_local_u64_address(acpi_handle handle, u64 *addr)
 281 {
 282         acpi_status status;
 283
 284         status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, addr);
 285         if (ACPI_FAILURE(status))
 286                 return -ENODATA;
 287         return 0;
 288 }
 289 EXPORT_SYMBOL(acpi_get_local_u64_address);
 290
 291 int acpi_get_local_address(acpi_handle handle, u32 *addr)
 292 {
 293         u64 adr;
 294         int ret;
 295
 296         ret = acpi_get_local_u64_address(handle, &adr);
 297         if (ret < 0)
 298                 return ret;
 299         *addr = (u32)adr;
 300         return 0;
 301 }
 302 EXPORT_SYMBOL(acpi_get_local_address);
 303
 304 #define ACPI_MAX_SUB_BUF_SIZE   9
 305
 306 const char *acpi_get_subsystem_id(acpi_handle handle)
 307 {
 308         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 309         union acpi_object *obj;
 310         acpi_status status;
 311         const char *sub;
 312         size_t len;
 313
 314         status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
 315         if (ACPI_FAILURE(status)) {
 316                 acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
 317                 return ERR_PTR(-ENODATA);
 318         }
 319
 320         obj = buffer.pointer;
 321         if (obj->type == ACPI_TYPE_STRING) {
 322                 len = strlen(obj->string.pointer);
 323                 if (len < ACPI_MAX_SUB_BUF_SIZE && len > 0) {
 324                         sub = kstrdup(obj->string.pointer, GFP_KERNEL);
 325                         if (!sub)
 326                                 sub = ERR_PTR(-ENOMEM);
 327                 } else {
 328                         acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", len);
 329                         sub = ERR_PTR(-ENODATA);
 330                 }
 331         } else {
 332                 acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
 333                 sub = ERR_PTR(-ENODATA);
 334         }
 335
 336         acpi_os_free(buffer.pointer);
 337
 338         return sub;
 339 }
 340 EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);
 341
 342 bool acpi_evaluate_reference(acpi_handle handle, acpi_string pathname,
 343                              struct acpi_object_list *arguments,
 344                              struct acpi_handle_list *list)
 345 {
 346         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 347         union acpi_object *package;
 348         acpi_status status;
 349         bool ret = false;
 350         u32 i;
 351
 352         if (!list)
 353                 return false;
 354
 355         /* Evaluate object. */
 356
 357         status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
 358         if (ACPI_FAILURE(status))
 359                 goto end;
 360
 361         package = buffer.pointer;
 362
 363         if (buffer.length == 0 || !package ||
 364             package->type != ACPI_TYPE_PACKAGE || !package->package.count)
 365                 goto err;
 366
 367         list->count = package->package.count;
 368         list->handles = kcalloc(list->count, sizeof(*list->handles), GFP_KERNEL);
 369         if (!list->handles)
 370                 goto err_clear;
 371
 372         /* Extract package data. */
 373
 374         for (i = 0; i < list->count; i++) {
 375                 union acpi_object *element = &(package->package.elements[i]);
 376
 377                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE ||
 378                     !element->reference.handle)
 379                         goto err_free;
 380
 381                 /* Get the  acpi_handle. */
 382
 383                 list->handles[i] = element->reference.handle;
 384                 acpi_handle_debug(list->handles[i], "Found in reference list\n");
 385         }
 386
 387         ret = true;
 388
 389 end:
 390         kfree(buffer.pointer);
 391
 392         return ret;
 393
 394 err_free:
 395         kfree(list->handles);
 396         list->handles = NULL;
 397
 398 err_clear:
 399         list->count = 0;
 400
 401 err:
 402         acpi_util_eval_error(handle, pathname, status);
 403         goto end;
 404 }
 405
 406 EXPORT_SYMBOL(acpi_evaluate_reference);
 407
 408 /**
 409  * acpi_handle_list_equal - Check if two ACPI handle lists are the same
 410  * @list1: First list to compare.
 411  * @list2: Second list to compare.
 412  *
 413  * Return true if the given ACPI handle lists are of the same size and
 414  * contain the same ACPI handles in the same order.  Otherwise, return false.
 415  */
 416 bool acpi_handle_list_equal(struct acpi_handle_list *list1,
 417                             struct acpi_handle_list *list2)
 418 {
 419         return list1->count == list2->count &&
 420                 !memcmp(list1->handles, list2->handles,
 421                         list1->count * sizeof(*list1->handles));
 422 }
 423 EXPORT_SYMBOL_GPL(acpi_handle_list_equal);
 424
 425 /**
 426  * acpi_handle_list_replace - Replace one ACPI handle list with another
 427  * @dst: ACPI handle list to replace.
 428  * @src: Source ACPI handle list.
 429  *
 430  * Free the handles table in @dst, move the handles table from @src to @dst,
 431  * copy count from @src to @dst and clear @src.
 432  */
 433 void acpi_handle_list_replace(struct acpi_handle_list *dst,
 434                               struct acpi_handle_list *src)
 435 {
 436         if (dst->count)
 437                 kfree(dst->handles);
 438
 439         dst->count = src->count;
 440         dst->handles = src->handles;
 441
 442         src->handles = NULL;
 443         src->count = 0;
 444 }
 445 EXPORT_SYMBOL_GPL(acpi_handle_list_replace);
 446
 447 /**
 448  * acpi_handle_list_free - Free the handles table in an ACPI handle list
 449  * @list: ACPI handle list to free.
 450  *
 451  * Free the handles table in @list and clear its count field.
 452  */
 453 void acpi_handle_list_free(struct acpi_handle_list *list)
 454 {
 455         if (!list->count)
 456                 return;
 457
 458         kfree(list->handles);
 459         list->count = 0;
 460 }
 461 EXPORT_SYMBOL_GPL(acpi_handle_list_free);
 462
 463 /**
 464  * acpi_device_dep - Check ACPI device dependency
 465  * @target: ACPI handle of the target ACPI device.
 466  * @match: ACPI handle to look up in the target's _DEP list.
 467  *
 468  * Return true if @match is present in the list returned by _DEP for
 469  * @target or false otherwise.
 470  */
 471 bool acpi_device_dep(acpi_handle target, acpi_handle match)
 472 {
 473         struct acpi_handle_list dep_devices;
 474         bool ret = false;
 475         int i;
 476
 477         if (!acpi_has_method(target, "_DEP"))
 478                 return false;
 479
 480         if (!acpi_evaluate_reference(target, "_DEP", NULL, &dep_devices)) {
 481                 acpi_handle_debug(target, "Failed to evaluate _DEP.\n");
 482                 return false;
 483         }
 484
 485         for (i = 0; i < dep_devices.count; i++) {
 486                 if (dep_devices.handles[i] == match) {
 487                         ret = true;
 488                         break;
 489                 }
 490         }
 491
 492         acpi_handle_list_free(&dep_devices);
 493         return ret;
 494 }
 495 EXPORT_SYMBOL_GPL(acpi_device_dep);
 496
 497 acpi_status
 498 acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
 499 {
 500         acpi_status status;
 501         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 502         union acpi_object *output;
 503
 504         status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
 505
 506         if (ACPI_FAILURE(status))
 507                 return status;
 508
 509         output = buffer.pointer;
 510
 511         if (!output || output->type != ACPI_TYPE_PACKAGE
 512             || !output->package.count
 513             || output->package.elements[0].type != ACPI_TYPE_BUFFER
 514             || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
 515                 status = AE_TYPE;
 516                 goto out;
 517         }
 518
 519         status = acpi_decode_pld_buffer(
 520                         output->package.elements[0].buffer.pointer,
 521                         output->package.elements[0].buffer.length,
 522                         pld);
 523
 524 out:
 525         kfree(buffer.pointer);
 526         return status;
 527 }
 528 EXPORT_SYMBOL(acpi_get_physical_device_location);
 529
 530 /**
 531  * acpi_evaluate_ost: Evaluate _OST for hotplug operations
 532  * @handle: ACPI device handle
 533  * @source_event: source event code
 534  * @status_code: status code
 535  * @status_buf: optional detailed information (NULL if none)
 536  *
 537  * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
 538  * must call this function when evaluating _OST for hotplug operations.
 539  * When the platform does not support _OST, this function has no effect.
 540  */
 541 acpi_status
 542 acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
 543                   struct acpi_buffer *status_buf)
 544 {
 545         union acpi_object params[3] = {
 546                 {.type = ACPI_TYPE_INTEGER,},
 547                 {.type = ACPI_TYPE_INTEGER,},
 548                 {.type = ACPI_TYPE_BUFFER,}
 549         };
 550         struct acpi_object_list arg_list = {3, params};
 551
 552         params[0].integer.value = source_event;
 553         params[1].integer.value = status_code;
 554         if (status_buf != NULL) {
 555                 params[2].buffer.pointer = status_buf->pointer;
 556                 params[2].buffer.length = status_buf->length;
 557         } else {
 558                 params[2].buffer.pointer = NULL;
 559                 params[2].buffer.length = 0;
 560         }
 561
 562         return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
 563 }
 564 EXPORT_SYMBOL(acpi_evaluate_ost);
 565
 566 /**
 567  * acpi_handle_path: Return the object path of handle
 568  * @handle: ACPI device handle
 569  *
 570  * Caller must free the returned buffer
 571  */
 572 char *acpi_handle_path(acpi_handle handle)
 573 {
 574         struct acpi_buffer buffer = {
 575                 .length = ACPI_ALLOCATE_BUFFER,
 576                 .pointer = NULL
 577         };
 578
 579         if (in_interrupt() ||
 580             acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
 581                 return NULL;
 582         return buffer.pointer;
 583 }
 584
 585 /**
 586  * acpi_handle_printk: Print message with ACPI prefix and object path
 587  * @level: log level
 588  * @handle: ACPI device handle
 589  * @fmt: format string
 590  *
 591  * This function is called through acpi_handle_<level> macros and prints
 592  * a message with ACPI prefix and object path.  This function acquires
 593  * the global namespace mutex to obtain an object path.  In interrupt
 594  * context, it shows the object path as <n/a>.
 595  */
 596 void
 597 acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
 598 {
 599         struct va_format vaf;
 600         va_list args;
 601         const char *path;
 602
 603         va_start(args, fmt);
 604         vaf.fmt = fmt;
 605         vaf.va = &args;
 606
 607         path = acpi_handle_path(handle);
 608         printk("%sACPI: %s: %pV", level, path ? path : "<n/a>", &vaf);
 609
 610         va_end(args);
 611         kfree(path);
 612 }
 613 EXPORT_SYMBOL(acpi_handle_printk);
 614
 615 #if defined(CONFIG_DYNAMIC_DEBUG)
 616 /**
 617  * __acpi_handle_debug: pr_debug with ACPI prefix and object path
 618  * @descriptor: Dynamic Debug descriptor
 619  * @handle: ACPI device handle
 620  * @fmt: format string
 621  *
 622  * This function is called through acpi_handle_debug macro and debug
 623  * prints a message with ACPI prefix and object path. This function
 624  * acquires the global namespace mutex to obtain an object path.  In
 625  * interrupt context, it shows the object path as <n/a>.
 626  */
 627 void
 628 __acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
 629                     const char *fmt, ...)
 630 {
 631         struct va_format vaf;
 632         va_list args;
 633         const char *path;
 634
 635         va_start(args, fmt);
 636         vaf.fmt = fmt;
 637         vaf.va = &args;
 638
 639         path = acpi_handle_path(handle);
 640         __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
 641
 642         va_end(args);
 643         kfree(path);
 644 }
 645 EXPORT_SYMBOL(__acpi_handle_debug);
 646 #endif
 647
 648 /**
 649  * acpi_evaluation_failure_warn - Log evaluation failure warning.
 650  * @handle: Parent object handle.
 651  * @name: Name of the object whose evaluation has failed.
 652  * @status: Status value returned by the failing object evaluation.
 653  */
 654 void acpi_evaluation_failure_warn(acpi_handle handle, const char *name,
 655                                   acpi_status status)
 656 {
 657         acpi_handle_warn(handle, "%s evaluation failed: %s\n", name,
 658                          acpi_format_exception(status));
 659 }
 660 EXPORT_SYMBOL_GPL(acpi_evaluation_failure_warn);
 661
 662 /**
 663  * acpi_has_method: Check whether @handle has a method named @name
 664  * @handle: ACPI device handle
 665  * @name: name of object or method
 666  *
 667  * Check whether @handle has a method named @name.
 668  */
 669 bool acpi_has_method(acpi_handle handle, char *name)
 670 {
 671         acpi_handle tmp;
 672
 673         return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
 674 }
 675 EXPORT_SYMBOL(acpi_has_method);
 676
 677 acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
 678                                        u64 arg)
 679 {
 680         union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
 681         struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
 682
 683         obj.integer.value = arg;
 684
 685         return acpi_evaluate_object(handle, method, &arg_list, NULL);
 686 }
 687 EXPORT_SYMBOL(acpi_execute_simple_method);
 688
 689 /**
 690  * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
 691  * @handle: ACPI device handle
 692  *
 693  * Evaluate device's _EJ0 method for hotplug operations.
 694  */
 695 acpi_status acpi_evaluate_ej0(acpi_handle handle)
 696 {
 697         acpi_status status;
 698
 699         status = acpi_execute_simple_method(handle, "_EJ0", 1);
 700         if (status == AE_NOT_FOUND)
 701                 acpi_handle_warn(handle, "No _EJ0 support for device\n");
 702         else if (ACPI_FAILURE(status))
 703                 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
 704
 705         return status;
 706 }
 707
 708 /**
 709  * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
 710  * @handle: ACPI device handle
 711  * @lock: lock device if non-zero, otherwise unlock device
 712  *
 713  * Evaluate device's _LCK method if present to lock/unlock device
 714  */
 715 acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
 716 {
 717         acpi_status status;
 718
 719         status = acpi_execute_simple_method(handle, "_LCK", !!lock);
 720         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 721                 if (lock)
 722                         acpi_handle_warn(handle,
 723                                 "Locking device failed (0x%x)\n", status);
 724                 else
 725                         acpi_handle_warn(handle,
 726                                 "Unlocking device failed (0x%x)\n", status);
 727         }
 728
 729         return status;
 730 }
 731
 732 /**
 733  * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
 734  * @handle: ACPI device handle
 735  * @space_id: ACPI address space id to register OpRegion presence for
 736  * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
 737  *            ACPI_REG_DISCONNECT
 738  *
 739  * Evaluate device's _REG method to register OpRegion presence.
 740  */
 741 acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
 742 {
 743         struct acpi_object_list arg_list;
 744         union acpi_object params[2];
 745
 746         params[0].type = ACPI_TYPE_INTEGER;
 747         params[0].integer.value = space_id;
 748         params[1].type = ACPI_TYPE_INTEGER;
 749         params[1].integer.value = function;
 750         arg_list.count = 2;
 751         arg_list.pointer = params;
 752
 753         return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);
 754 }
 755 EXPORT_SYMBOL(acpi_evaluate_reg);
 756
 757 /**
 758  * acpi_evaluate_dsm - evaluate device's _DSM method
 759  * @handle: ACPI device handle
 760  * @guid: GUID of requested functions, should be 16 bytes
 761  * @rev: revision number of requested function
 762  * @func: requested function number
 763  * @argv4: the function specific parameter
 764  *
 765  * Evaluate device's _DSM method with specified GUID, revision id and
 766  * function number. Caller needs to free the returned object.
 767  *
 768  * Though ACPI defines the fourth parameter for _DSM should be a package,
 769  * some old BIOSes do expect a buffer or an integer etc.
 770  */
 771 union acpi_object *
 772 acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
 773                   union acpi_object *argv4)
 774 {
 775         acpi_status ret;
 776         struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
 777         union acpi_object params[4];
 778         struct acpi_object_list input = {
 779                 .count = 4,
 780                 .pointer = params,
 781         };
 782
 783         params[0].type = ACPI_TYPE_BUFFER;
 784         params[0].buffer.length = 16;
 785         params[0].buffer.pointer = (u8 *)guid;
 786         params[1].type = ACPI_TYPE_INTEGER;
 787         params[1].integer.value = rev;
 788         params[2].type = ACPI_TYPE_INTEGER;
 789         params[2].integer.value = func;
 790         if (argv4) {
 791                 params[3] = *argv4;
 792         } else {
 793                 params[3].type = ACPI_TYPE_PACKAGE;
 794                 params[3].package.count = 0;
 795                 params[3].package.elements = NULL;
 796         }
 797
 798         ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
 799         if (ACPI_SUCCESS(ret))
 800                 return (union acpi_object *)buf.pointer;
 801
 802         if (ret != AE_NOT_FOUND)
 803                 acpi_handle_warn(handle,
 804                                  "failed to evaluate _DSM %pUb rev:%lld func:%lld (0x%x)\n",
 805                                  guid, rev, func, ret);
 806
 807         return NULL;
 808 }
 809 EXPORT_SYMBOL(acpi_evaluate_dsm);
 810
 811 /**
 812  * acpi_check_dsm - check if _DSM method supports requested functions.
 813  * @handle: ACPI device handle
 814  * @guid: GUID of requested functions, should be 16 bytes at least
 815  * @rev: revision number of requested functions
 816  * @funcs: bitmap of requested functions
 817  *
 818  * Evaluate device's _DSM method to check whether it supports requested
 819  * functions. Currently only support 64 functions at maximum, should be
 820  * enough for now.
 821  */
 822 bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
 823 {
 824         int i;
 825         u64 mask = 0;
 826         union acpi_object *obj;
 827
 828         if (funcs == 0)
 829                 return false;
 830
 831         obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
 832         if (!obj)
 833                 return false;
 834
 835         /* For compatibility, old BIOSes may return an integer */
 836         if (obj->type == ACPI_TYPE_INTEGER)
 837                 mask = obj->integer.value;
 838         else if (obj->type == ACPI_TYPE_BUFFER)
 839                 for (i = 0; i < obj->buffer.length && i < 8; i++)
 840                         mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
 841         ACPI_FREE(obj);
 842
 843         /*
 844          * Bit 0 indicates whether there's support for any functions other than
 845          * function 0 for the specified GUID and revision.
 846          */
 847         if ((mask & 0x1) && (mask & funcs) == funcs)
 848                 return true;
 849
 850         return false;
 851 }
 852 EXPORT_SYMBOL(acpi_check_dsm);
 853
 854 /**
 855  * acpi_dev_uid_to_integer - treat ACPI device _UID as integer
 856  * @adev: ACPI device to get _UID from
 857  * @integer: output buffer for integer
 858  *
 859  * Considers _UID as integer and converts it to @integer.
 860  *
 861  * Returns 0 on success, or negative error code otherwise.
 862  */
 863 int acpi_dev_uid_to_integer(struct acpi_device *adev, u64 *integer)
 864 {
 865         const char *uid;
 866
 867         if (!adev)
 868                 return -ENODEV;
 869
 870         uid = acpi_device_uid(adev);
 871         if (!uid)
 872                 return -ENODATA;
 873
 874         return kstrtou64(uid, 0, integer);
 875 }
 876 EXPORT_SYMBOL(acpi_dev_uid_to_integer);
 877
 878 /**
 879  * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
 880  * @hid: Hardware ID of the device.
 881  *
 882  * Return %true if the device was present at the moment of invocation.
 883  * Note that if the device is pluggable, it may since have disappeared.
 884  *
 885  * For this function to work, acpi_bus_scan() must have been executed
 886  * which happens in the subsys_initcall() subsection. Hence, do not
 887  * call from a subsys_initcall() or earlier (use acpi_get_devices()
 888  * instead). Calling from module_init() is fine (which is synonymous
 889  * with device_initcall()).
 890  */
 891 bool acpi_dev_found(const char *hid)
 892 {
 893         struct acpi_device_bus_id *acpi_device_bus_id;
 894         bool found = false;
 895
 896         mutex_lock(&acpi_device_lock);
 897         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
 898                 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
 899                         found = true;
 900                         break;
 901                 }
 902         mutex_unlock(&acpi_device_lock);
 903
 904         return found;
 905 }
 906 EXPORT_SYMBOL(acpi_dev_found);
 907
 908 struct acpi_dev_match_info {
 909         struct acpi_device_id hid[2];
 910         const char *uid;
 911         s64 hrv;
 912 };
 913
 914 static int acpi_dev_match_cb(struct device *dev, const void *data)
 915 {
 916         struct acpi_device *adev = to_acpi_device(dev);
 917         const struct acpi_dev_match_info *match = data;
 918         unsigned long long hrv;
 919         acpi_status status;
 920
 921         if (acpi_match_device_ids(adev, match->hid))
 922                 return 0;
 923
 924         if (match->uid && !acpi_dev_uid_match(adev, match->uid))
 925                 return 0;
 926
 927         if (match->hrv == -1)
 928                 return 1;
 929
 930         status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
 931         if (ACPI_FAILURE(status))
 932                 return 0;
 933
 934         return hrv == match->hrv;
 935 }
 936
 937 /**
 938  * acpi_dev_present - Detect that a given ACPI device is present
 939  * @hid: Hardware ID of the device.
 940  * @uid: Unique ID of the device, pass NULL to not check _UID
 941  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
 942  *
 943  * Return %true if a matching device was present at the moment of invocation.
 944  * Note that if the device is pluggable, it may since have disappeared.
 945  *
 946  * Note that unlike acpi_dev_found() this function checks the status
 947  * of the device. So for devices which are present in the DSDT, but
 948  * which are disabled (their _STA callback returns 0) this function
 949  * will return false.
 950  *
 951  * For this function to work, acpi_bus_scan() must have been executed
 952  * which happens in the subsys_initcall() subsection. Hence, do not
 953  * call from a subsys_initcall() or earlier (use acpi_get_devices()
 954  * instead). Calling from module_init() is fine (which is synonymous
 955  * with device_initcall()).
 956  */
 957 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
 958 {
 959         struct acpi_dev_match_info match = {};
 960         struct device *dev;
 961
 962         strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
 963         match.uid = uid;
 964         match.hrv = hrv;
 965
 966         dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
 967         put_device(dev);
 968         return !!dev;
 969 }
 970 EXPORT_SYMBOL(acpi_dev_present);
 971
 972 /**
 973  * acpi_dev_get_next_match_dev - Return the next match of ACPI device
 974  * @adev: Pointer to the previous ACPI device matching this @hid, @uid and @hrv
 975  * @hid: Hardware ID of the device.
 976  * @uid: Unique ID of the device, pass NULL to not check _UID
 977  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
 978  *
 979  * Return the next match of ACPI device if another matching device was present
 980  * at the moment of invocation, or NULL otherwise.
 981  *
 982  * The caller is responsible for invoking acpi_dev_put() on the returned device.
 983  * On the other hand the function invokes  acpi_dev_put() on the given @adev
 984  * assuming that its reference counter had been increased beforehand.
 985  *
 986  * See additional information in acpi_dev_present() as well.
 987  */
 988 struct acpi_device *
 989 acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv)
 990 {
 991         struct device *start = adev ? &adev->dev : NULL;
 992         struct acpi_dev_match_info match = {};
 993         struct device *dev;
 994
 995         strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
 996         match.uid = uid;
 997         match.hrv = hrv;
 998
 999         dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);
1000         acpi_dev_put(adev);
1001         return dev ? to_acpi_device(dev) : NULL;
1002 }
1003 EXPORT_SYMBOL(acpi_dev_get_next_match_dev);
1004
1005 /**
1006  * acpi_dev_get_first_match_dev - Return the first match of ACPI device
1007  * @hid: Hardware ID of the device.
1008  * @uid: Unique ID of the device, pass NULL to not check _UID
1009  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
1010  *
1011  * Return the first match of ACPI device if a matching device was present
1012  * at the moment of invocation, or NULL otherwise.
1013  *
1014  * The caller is responsible for invoking acpi_dev_put() on the returned device.
1015  *
1016  * See additional information in acpi_dev_present() as well.
1017  */
1018 struct acpi_device *
1019 acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
1020 {
1021         return acpi_dev_get_next_match_dev(NULL, hid, uid, hrv);
1022 }
1023 EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
1024
1025 /**
1026  * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine
1027  *
1028  * Return true when running on an ACPI-reduced-hw machine, false otherwise.
1029  */
1030 bool acpi_reduced_hardware(void)
1031 {
1032         return acpi_gbl_reduced_hardware;
1033 }
1034 EXPORT_SYMBOL_GPL(acpi_reduced_hardware);
1035
1036 /*
1037  * acpi_backlight= handling, this is done here rather then in video_detect.c
1038  * because __setup cannot be used in modules.
1039  */
1040 char acpi_video_backlight_string[16];
1041 EXPORT_SYMBOL(acpi_video_backlight_string);
1042
1043 static int __init acpi_backlight(char *str)
1044 {
1045         strscpy(acpi_video_backlight_string, str,
1046                 sizeof(acpi_video_backlight_string));
1047         return 1;
1048 }
1049 __setup("acpi_backlight=", acpi_backlight);
1050
1051 /**
1052  * acpi_match_platform_list - Check if the system matches with a given list
1053  * @plat: pointer to acpi_platform_list table terminated by a NULL entry
1054  *
1055  * Return the matched index if the system is found in the platform list.
1056  * Otherwise, return a negative error code.
1057  */
1058 int acpi_match_platform_list(const struct acpi_platform_list *plat)
1059 {
1060         struct acpi_table_header hdr;
1061         int idx = 0;
1062
1063         if (acpi_disabled)
1064                 return -ENODEV;
1065
1066         for (; plat->oem_id[0]; plat++, idx++) {
1067                 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
1068                         continue;
1069
1070                 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
1071                         continue;
1072
1073                 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
1074                         continue;
1075
1076                 if ((plat->pred == all_versions) ||
1077                     (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
1078                     (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
1079                     (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
1080                         return idx;
1081         }
1082
1083         return -ENODEV;
1084 }
1085 EXPORT_SYMBOL(acpi_match_platform_list);