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 #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
  22 ACPI_MODULE_NAME("utils");
  23
  24 /* --------------------------------------------------------------------------
  25                             Object Evaluation Helpers
  26    -------------------------------------------------------------------------- */
  27 static void
  28 acpi_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
  41 acpi_status
  42 acpi_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
 263 EXPORT_SYMBOL(acpi_extract_package);
 264
 265 acpi_status
 266 acpi_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
 297 EXPORT_SYMBOL(acpi_evaluate_integer);
 298
 299 acpi_status
 300 acpi_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
 381 EXPORT_SYMBOL(acpi_evaluate_reference);
 382
 383 acpi_status
 384 acpi_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
 410 out:
 411         kfree(buffer.pointer);
 412         return status;
 413 }
 414 EXPORT_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  */
 427 acpi_status
 428 acpi_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 }
 450 EXPORT_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  */
 458 static 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  */
 482 void
 483 acpi_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 }
 499 EXPORT_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  */
 513 void
 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 }
 531 EXPORT_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  */
 541 bool 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 }
 547 EXPORT_SYMBOL(acpi_has_method);
 548
 549 acpi_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 }
 559 EXPORT_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  */
 567 acpi_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  */
 587 acpi_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  */
 613 acpi_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 }
 627 EXPORT_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  */
 643 union acpi_object *
 644 acpi_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 }
 680 EXPORT_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  */
 693 bool 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 }
 723 EXPORT_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  */
 734 bool 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 }
 748 EXPORT_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  */
 763 bool 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 }
 778 EXPORT_SYMBOL(acpi_dev_found);
 779
 780 struct acpi_dev_match_info {
 781         struct acpi_device_id hid[2];
 782         const char *uid;
 783         s64 hrv;
 784 };
 785
 786 static 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  */
 830 bool 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 }
 843 EXPORT_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  */
 858 struct acpi_device *
 859 acpi_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 }
 871 EXPORT_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  */
 877 char acpi_video_backlight_string[16];
 878 EXPORT_SYMBOL(acpi_video_backlight_string);
 879
 880 static 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  */
 895 int 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 }
 922 EXPORT_SYMBOL(acpi_match_platform_list);