drivers/acpi/acpica/nsrepair2.c

   1 /******************************************************************************
   2  *
   3  * Module Name: nsrepair2 - Repair for objects returned by specific
   4  *                          predefined methods
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2009, Intel Corp.
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45 #include <acpi/acpi.h>
  46 #include "accommon.h"
  47 #include "acnamesp.h"
  48
  49 #define _COMPONENT          ACPI_NAMESPACE
  50 ACPI_MODULE_NAME("nsrepair2")
  51
  52 /*
  53  * Information structure and handler for ACPI predefined names that can
  54  * be repaired on a per-name basis.
  55  */
  56 typedef
  57 acpi_status(*acpi_repair_function) (struct acpi_predefined_data *data,
  58                                     union acpi_operand_object **return_object_ptr);
  59
  60 typedef struct acpi_repair_info {
  61         char name[ACPI_NAME_SIZE];
  62         acpi_repair_function repair_function;
  63
  64 } acpi_repair_info;
  65
  66 /* Local prototypes */
  67
  68 static const struct acpi_repair_info *acpi_ns_match_repairable_name(struct
  69                                                                     acpi_namespace_node
  70                                                                     *node);
  71
  72 static acpi_status
  73 acpi_ns_repair_ALR(struct acpi_predefined_data *data,
  74                    union acpi_operand_object **return_object_ptr);
  75
  76 static acpi_status
  77 acpi_ns_repair_FDE(struct acpi_predefined_data *data,
  78                    union acpi_operand_object **return_object_ptr);
  79
  80 static acpi_status
  81 acpi_ns_repair_PSS(struct acpi_predefined_data *data,
  82                    union acpi_operand_object **return_object_ptr);
  83
  84 static acpi_status
  85 acpi_ns_repair_TSS(struct acpi_predefined_data *data,
  86                    union acpi_operand_object **return_object_ptr);
  87
  88 static acpi_status
  89 acpi_ns_check_sorted_list(struct acpi_predefined_data *data,
  90                           union acpi_operand_object *return_object,
  91                           u32 expected_count,
  92                           u32 sort_index,
  93                           u8 sort_direction, char *sort_key_name);
  94
  95 static acpi_status
  96 acpi_ns_remove_null_elements(union acpi_operand_object *package);
  97
  98 static acpi_status
  99 acpi_ns_sort_list(union acpi_operand_object **elements,
 100                   u32 count, u32 index, u8 sort_direction);
 101
 102 /* Values for sort_direction above */
 103
 104 #define ACPI_SORT_ASCENDING     0
 105 #define ACPI_SORT_DESCENDING    1
 106
 107 /*
 108  * This table contains the names of the predefined methods for which we can
 109  * perform more complex repairs.
 110  *
 111  * As necessary:
 112  *
 113  * _ALR: Sort the list ascending by ambient_illuminance
 114  * _FDE: Convert a Package or Buffer of BYTEs to a Buffer of DWORDs
 115  * _GTM: Convert a Package or Buffer of BYTEs to a Buffer of DWORDs
 116  * _PSS: Sort the list descending by Power
 117  * _TSS: Sort the list descending by Power
 118  */
 119 static const struct acpi_repair_info acpi_ns_repairable_names[] = {
 120         {"_ALR", acpi_ns_repair_ALR},
 121         {"_FDE", acpi_ns_repair_FDE},
 122         {"_GTM", acpi_ns_repair_FDE},   /* _GTM has same repair as _FDE */
 123         {"_PSS", acpi_ns_repair_PSS},
 124         {"_TSS", acpi_ns_repair_TSS},
 125         {{0, 0, 0, 0}, NULL}    /* Table terminator */
 126 };
 127
 128 #define ACPI_FDE_FIELD_COUNT        5
 129 #define ACPI_FDE_BYTE_BUFFER_SIZE   5
 130 #define ACPI_FDE_DWORD_BUFFER_SIZE  (ACPI_FDE_FIELD_COUNT * sizeof (u32))
 131
 132 /******************************************************************************
 133  *
 134  * FUNCTION:    acpi_ns_complex_repairs
 135  *
 136  * PARAMETERS:  Data                - Pointer to validation data structure
 137  *              Node                - Namespace node for the method/object
 138  *              validate_status     - Original status of earlier validation
 139  *              return_object_ptr   - Pointer to the object returned from the
 140  *                                    evaluation of a method or object
 141  *
 142  * RETURN:      Status. AE_OK if repair was successful. If name is not
 143  *              matched, validate_status is returned.
 144  *
 145  * DESCRIPTION: Attempt to repair/convert a return object of a type that was
 146  *              not expected.
 147  *
 148  *****************************************************************************/
 149
 150 acpi_status
 151 acpi_ns_complex_repairs(struct acpi_predefined_data *data,
 152                         struct acpi_namespace_node *node,
 153                         acpi_status validate_status,
 154                         union acpi_operand_object **return_object_ptr)
 155 {
 156         const struct acpi_repair_info *predefined;
 157         acpi_status status;
 158
 159         /* Check if this name is in the list of repairable names */
 160
 161         predefined = acpi_ns_match_repairable_name(node);
 162         if (!predefined) {
 163                 return (validate_status);
 164         }
 165
 166         status = predefined->repair_function(data, return_object_ptr);
 167         return (status);
 168 }
 169
 170 /******************************************************************************
 171  *
 172  * FUNCTION:    acpi_ns_match_repairable_name
 173  *
 174  * PARAMETERS:  Node                - Namespace node for the method/object
 175  *
 176  * RETURN:      Pointer to entry in repair table. NULL indicates not found.
 177  *
 178  * DESCRIPTION: Check an object name against the repairable object list.
 179  *
 180  *****************************************************************************/
 181
 182 static const struct acpi_repair_info *acpi_ns_match_repairable_name(struct
 183                                                                     acpi_namespace_node
 184                                                                     *node)
 185 {
 186         const struct acpi_repair_info *this_name;
 187
 188         /* Search info table for a repairable predefined method/object name */
 189
 190         this_name = acpi_ns_repairable_names;
 191         while (this_name->repair_function) {
 192                 if (ACPI_COMPARE_NAME(node->name.ascii, this_name->name)) {
 193                         return (this_name);
 194                 }
 195                 this_name++;
 196         }
 197
 198         return (NULL);          /* Not found */
 199 }
 200
 201 /******************************************************************************
 202  *
 203  * FUNCTION:    acpi_ns_repair_ALR
 204  *
 205  * PARAMETERS:  Data                - Pointer to validation data structure
 206  *              return_object_ptr   - Pointer to the object returned from the
 207  *                                    evaluation of a method or object
 208  *
 209  * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 210  *
 211  * DESCRIPTION: Repair for the _ALR object. If necessary, sort the object list
 212  *              ascending by the ambient illuminance values.
 213  *
 214  *****************************************************************************/
 215
 216 static acpi_status
 217 acpi_ns_repair_ALR(struct acpi_predefined_data *data,
 218                    union acpi_operand_object **return_object_ptr)
 219 {
 220         union acpi_operand_object *return_object = *return_object_ptr;
 221         acpi_status status;
 222
 223         status = acpi_ns_check_sorted_list(data, return_object, 2, 1,
 224                                            ACPI_SORT_ASCENDING,
 225                                            "AmbientIlluminance");
 226
 227         return (status);
 228 }
 229
 230 /******************************************************************************
 231  *
 232  * FUNCTION:    acpi_ns_repair_FDE
 233  *
 234  * PARAMETERS:  Data                - Pointer to validation data structure
 235  *              return_object_ptr   - Pointer to the object returned from the
 236  *                                    evaluation of a method or object
 237  *
 238  * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 239  *
 240  * DESCRIPTION: Repair for the _FDE and _GTM objects. The expected return
 241  *              value is a Buffer of 5 DWORDs. This function repairs two
 242  *              possible problems:
 243  *              1) The return value is a Buffer of BYTEs, not DWORDs
 244  *              2) The return value is a Package of Integer objects
 245  *
 246  *****************************************************************************/
 247
 248 static acpi_status
 249 acpi_ns_repair_FDE(struct acpi_predefined_data *data,
 250                    union acpi_operand_object **return_object_ptr)
 251 {
 252         union acpi_operand_object *return_object = *return_object_ptr;
 253         union acpi_operand_object **elements;
 254         union acpi_operand_object *buffer_object;
 255         u8 *byte_buffer;
 256         u32 *dword_buffer;
 257         u32 count;
 258         u32 i;
 259
 260         switch (return_object->common.type) {
 261         case ACPI_TYPE_BUFFER:
 262
 263                 /* This is the expected type. Length should be (at least) 5 DWORDs */
 264
 265                 if (return_object->buffer.length >= ACPI_FDE_DWORD_BUFFER_SIZE) {
 266                         return (AE_OK);
 267                 }
 268
 269                 /* We can only repair if we have exactly 5 BYTEs */
 270
 271                 if (return_object->buffer.length != ACPI_FDE_BYTE_BUFFER_SIZE) {
 272                         ACPI_WARN_PREDEFINED((AE_INFO, data->pathname,
 273                                               data->node_flags,
 274                                               "Incorrect return buffer length %u, expected %u",
 275                                               return_object->buffer.length,
 276                                               ACPI_FDE_DWORD_BUFFER_SIZE));
 277
 278                         return (AE_AML_OPERAND_TYPE);
 279                 }
 280
 281                 /* Create the new (larger) buffer object */
 282
 283                 buffer_object =
 284                     acpi_ut_create_buffer_object(ACPI_FDE_DWORD_BUFFER_SIZE);
 285                 if (!buffer_object) {
 286                         return (AE_NO_MEMORY);
 287                 }
 288
 289                 /* Expand each byte to a DWORD */
 290
 291                 byte_buffer = return_object->buffer.pointer;
 292                 dword_buffer =
 293                     ACPI_CAST_PTR(u32, buffer_object->buffer.pointer);
 294
 295                 for (i = 0; i < ACPI_FDE_FIELD_COUNT; i++) {
 296                         *dword_buffer = (u32) *byte_buffer;
 297                         dword_buffer++;
 298                         byte_buffer++;
 299                 }
 300
 301                 ACPI_INFO_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 302                                       "Expanded Byte Buffer to expected DWord Buffer"));
 303                 break;
 304
 305         case ACPI_TYPE_PACKAGE:
 306
 307                 /* All elements of the Package must be integers */
 308
 309                 elements = return_object->package.elements;
 310                 count =
 311                     ACPI_MIN(ACPI_FDE_FIELD_COUNT,
 312                              return_object->package.count);
 313
 314                 for (i = 0; i < count; i++) {
 315                         if ((!*elements) ||
 316                             ((*elements)->common.type != ACPI_TYPE_INTEGER)) {
 317                                 return (AE_AML_OPERAND_TYPE);
 318                         }
 319                         elements++;
 320                 }
 321
 322                 /* Create the new buffer object to replace the Package */
 323
 324                 buffer_object =
 325                     acpi_ut_create_buffer_object(ACPI_FDE_DWORD_BUFFER_SIZE);
 326                 if (!buffer_object) {
 327                         return (AE_NO_MEMORY);
 328                 }
 329
 330                 /* Copy the package elements (integers) to the buffer */
 331
 332                 elements = return_object->package.elements;
 333                 dword_buffer =
 334                     ACPI_CAST_PTR(u32, buffer_object->buffer.pointer);
 335
 336                 for (i = 0; i < count; i++) {
 337                         *dword_buffer = (u32) (*elements)->integer.value;
 338                         dword_buffer++;
 339                         elements++;
 340                 }
 341
 342                 ACPI_INFO_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 343                                       "Converted Package to expected Buffer"));
 344                 break;
 345
 346         default:
 347                 return (AE_AML_OPERAND_TYPE);
 348         }
 349
 350         /* Delete the original return object, return the new buffer object */
 351
 352         acpi_ut_remove_reference(return_object);
 353         *return_object_ptr = buffer_object;
 354
 355         data->flags |= ACPI_OBJECT_REPAIRED;
 356         return (AE_OK);
 357 }
 358
 359 /******************************************************************************
 360  *
 361  * FUNCTION:    acpi_ns_repair_TSS
 362  *
 363  * PARAMETERS:  Data                - Pointer to validation data structure
 364  *              return_object_ptr   - Pointer to the object returned from the
 365  *                                    evaluation of a method or object
 366  *
 367  * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 368  *
 369  * DESCRIPTION: Repair for the _TSS object. If necessary, sort the object list
 370  *              descending by the power dissipation values.
 371  *
 372  *****************************************************************************/
 373
 374 static acpi_status
 375 acpi_ns_repair_TSS(struct acpi_predefined_data *data,
 376                    union acpi_operand_object **return_object_ptr)
 377 {
 378         union acpi_operand_object *return_object = *return_object_ptr;
 379         acpi_status status;
 380
 381         status = acpi_ns_check_sorted_list(data, return_object, 5, 1,
 382                                            ACPI_SORT_DESCENDING,
 383                                            "PowerDissipation");
 384
 385         return (status);
 386 }
 387
 388 /******************************************************************************
 389  *
 390  * FUNCTION:    acpi_ns_repair_PSS
 391  *
 392  * PARAMETERS:  Data                - Pointer to validation data structure
 393  *              return_object_ptr   - Pointer to the object returned from the
 394  *                                    evaluation of a method or object
 395  *
 396  * RETURN:      Status. AE_OK if object is OK or was repaired successfully
 397  *
 398  * DESCRIPTION: Repair for the _PSS object. If necessary, sort the object list
 399  *              by the CPU frequencies. Check that the power dissipation values
 400  *              are all proportional to CPU frequency (i.e., sorting by
 401  *              frequency should be the same as sorting by power.)
 402  *
 403  *****************************************************************************/
 404
 405 static acpi_status
 406 acpi_ns_repair_PSS(struct acpi_predefined_data *data,
 407                    union acpi_operand_object **return_object_ptr)
 408 {
 409         union acpi_operand_object *return_object = *return_object_ptr;
 410         union acpi_operand_object **outer_elements;
 411         u32 outer_element_count;
 412         union acpi_operand_object **elements;
 413         union acpi_operand_object *obj_desc;
 414         u32 previous_value;
 415         acpi_status status;
 416         u32 i;
 417
 418         /*
 419          * Entries (sub-packages) in the _PSS Package must be sorted by power
 420          * dissipation, in descending order. If it appears that the list is
 421          * incorrectly sorted, sort it. We sort by cpu_frequency, since this
 422          * should be proportional to the power.
 423          */
 424         status = acpi_ns_check_sorted_list(data, return_object, 6, 0,
 425                                            ACPI_SORT_DESCENDING,
 426                                            "CpuFrequency");
 427         if (ACPI_FAILURE(status)) {
 428                 return (status);
 429         }
 430
 431         /*
 432          * We now know the list is correctly sorted by CPU frequency. Check if
 433          * the power dissipation values are proportional.
 434          */
 435         previous_value = ACPI_UINT32_MAX;
 436         outer_elements = return_object->package.elements;
 437         outer_element_count = return_object->package.count;
 438
 439         for (i = 0; i < outer_element_count; i++) {
 440                 elements = (*outer_elements)->package.elements;
 441                 obj_desc = elements[1]; /* Index1 = power_dissipation */
 442
 443                 if ((u32) obj_desc->integer.value > previous_value) {
 444                         ACPI_WARN_PREDEFINED((AE_INFO, data->pathname,
 445                                               data->node_flags,
 446                                               "SubPackage[%u,%u] - suspicious power dissipation values",
 447                                               i - 1, i));
 448                 }
 449
 450                 previous_value = (u32) obj_desc->integer.value;
 451                 outer_elements++;
 452         }
 453
 454         return (AE_OK);
 455 }
 456
 457 /******************************************************************************
 458  *
 459  * FUNCTION:    acpi_ns_check_sorted_list
 460  *
 461  * PARAMETERS:  Data                - Pointer to validation data structure
 462  *              return_object       - Pointer to the top-level returned object
 463  *              expected_count      - Minimum length of each sub-package
 464  *              sort_index          - Sub-package entry to sort on
 465  *              sort_direction      - Ascending or descending
 466  *              sort_key_name       - Name of the sort_index field
 467  *
 468  * RETURN:      Status. AE_OK if the list is valid and is sorted correctly or
 469  *              has been repaired by sorting the list.
 470  *
 471  * DESCRIPTION: Check if the package list is valid and sorted correctly by the
 472  *              sort_index. If not, then sort the list.
 473  *
 474  *****************************************************************************/
 475
 476 static acpi_status
 477 acpi_ns_check_sorted_list(struct acpi_predefined_data *data,
 478                           union acpi_operand_object *return_object,
 479                           u32 expected_count,
 480                           u32 sort_index,
 481                           u8 sort_direction, char *sort_key_name)
 482 {
 483         u32 outer_element_count;
 484         union acpi_operand_object **outer_elements;
 485         union acpi_operand_object **elements;
 486         union acpi_operand_object *obj_desc;
 487         u32 i;
 488         u32 previous_value;
 489         acpi_status status;
 490
 491         /* The top-level object must be a package */
 492
 493         if (return_object->common.type != ACPI_TYPE_PACKAGE) {
 494                 return (AE_AML_OPERAND_TYPE);
 495         }
 496
 497         /*
 498          * Detect any NULL package elements and remove them from the
 499          * package.
 500          *
 501          * TBD: We may want to do this for all predefined names that
 502          * return a variable-length package of packages.
 503          */
 504         status = acpi_ns_remove_null_elements(return_object);
 505         if (status == AE_NULL_ENTRY) {
 506                 ACPI_INFO_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 507                                       "NULL elements removed from package"));
 508
 509                 /* Exit if package is now zero length */
 510
 511                 if (!return_object->package.count) {
 512                         return (AE_NULL_ENTRY);
 513                 }
 514         }
 515
 516         outer_elements = return_object->package.elements;
 517         outer_element_count = return_object->package.count;
 518         if (!outer_element_count) {
 519                 return (AE_AML_PACKAGE_LIMIT);
 520         }
 521
 522         previous_value = 0;
 523         if (sort_direction == ACPI_SORT_DESCENDING) {
 524                 previous_value = ACPI_UINT32_MAX;
 525         }
 526
 527         /* Examine each subpackage */
 528
 529         for (i = 0; i < outer_element_count; i++) {
 530
 531                 /* Each element of the top-level package must also be a package */
 532
 533                 if ((*outer_elements)->common.type != ACPI_TYPE_PACKAGE) {
 534                         return (AE_AML_OPERAND_TYPE);
 535                 }
 536
 537                 /* Each sub-package must have the minimum length */
 538
 539                 if ((*outer_elements)->package.count < expected_count) {
 540                         return (AE_AML_PACKAGE_LIMIT);
 541                 }
 542
 543                 elements = (*outer_elements)->package.elements;
 544                 obj_desc = elements[sort_index];
 545
 546                 if (obj_desc->common.type != ACPI_TYPE_INTEGER) {
 547                         return (AE_AML_OPERAND_TYPE);
 548                 }
 549
 550                 /*
 551                  * The list must be sorted in the specified order. If we detect a
 552                  * discrepancy, issue a warning and sort the entire list
 553                  */
 554                 if (((sort_direction == ACPI_SORT_ASCENDING) &&
 555                      (obj_desc->integer.value < previous_value)) ||
 556                     ((sort_direction == ACPI_SORT_DESCENDING) &&
 557                      (obj_desc->integer.value > previous_value))) {
 558                         status =
 559                             acpi_ns_sort_list(return_object->package.elements,
 560                                               outer_element_count, sort_index,
 561                                               sort_direction);
 562                         if (ACPI_FAILURE(status)) {
 563                                 return (status);
 564                         }
 565
 566                         data->flags |= ACPI_OBJECT_REPAIRED;
 567
 568                         ACPI_INFO_PREDEFINED((AE_INFO, data->pathname,
 569                                               data->node_flags,
 570                                               "Repaired unsorted list - now sorted by %s",
 571                                               sort_key_name));
 572                         return (AE_OK);
 573                 }
 574
 575                 previous_value = (u32) obj_desc->integer.value;
 576                 outer_elements++;
 577         }
 578
 579         return (AE_OK);
 580 }
 581
 582 /******************************************************************************
 583  *
 584  * FUNCTION:    acpi_ns_remove_null_elements
 585  *
 586  * PARAMETERS:  obj_desc            - A Package object
 587  *
 588  * RETURN:      Status. AE_NULL_ENTRY means that one or more elements were
 589  *              removed.
 590  *
 591  * DESCRIPTION: Remove all NULL package elements and update the package count.
 592  *
 593  *****************************************************************************/
 594
 595 static acpi_status
 596 acpi_ns_remove_null_elements(union acpi_operand_object *obj_desc)
 597 {
 598         union acpi_operand_object **source;
 599         union acpi_operand_object **dest;
 600         acpi_status status = AE_OK;
 601         u32 count;
 602         u32 new_count;
 603         u32 i;
 604
 605         count = obj_desc->package.count;
 606         new_count = count;
 607
 608         source = obj_desc->package.elements;
 609         dest = source;
 610
 611         /* Examine all elements of the package object */
 612
 613         for (i = 0; i < count; i++) {
 614                 if (!*source) {
 615                         status = AE_NULL_ENTRY;
 616                         new_count--;
 617                 } else {
 618                         *dest = *source;
 619                         dest++;
 620                 }
 621                 source++;
 622         }
 623
 624         if (status == AE_NULL_ENTRY) {
 625
 626                 /* NULL terminate list and update the package count */
 627
 628                 *dest = NULL;
 629                 obj_desc->package.count = new_count;
 630         }
 631
 632         return (status);
 633 }
 634
 635 /******************************************************************************
 636  *
 637  * FUNCTION:    acpi_ns_sort_list
 638  *
 639  * PARAMETERS:  Elements            - Package object element list
 640  *              Count               - Element count for above
 641  *              Index               - Sort by which package element
 642  *              sort_direction      - Ascending or Descending sort
 643  *
 644  * RETURN:      Status
 645  *
 646  * DESCRIPTION: Sort the objects that are in a package element list.
 647  *
 648  * NOTE: Assumes that all NULL elements have been removed from the package.
 649  *
 650  *****************************************************************************/
 651
 652 static acpi_status
 653 acpi_ns_sort_list(union acpi_operand_object **elements,
 654                   u32 count, u32 index, u8 sort_direction)
 655 {
 656         union acpi_operand_object *obj_desc1;
 657         union acpi_operand_object *obj_desc2;
 658         union acpi_operand_object *temp_obj;
 659         u32 i;
 660         u32 j;
 661
 662         /* Simple bubble sort */
 663
 664         for (i = 1; i < count; i++) {
 665                 for (j = (count - 1); j >= i; j--) {
 666                         obj_desc1 = elements[j - 1]->package.elements[index];
 667                         obj_desc2 = elements[j]->package.elements[index];
 668
 669                         if (((sort_direction == ACPI_SORT_ASCENDING) &&
 670                              (obj_desc1->integer.value >
 671                               obj_desc2->integer.value))
 672                             || ((sort_direction == ACPI_SORT_DESCENDING)
 673                                 && (obj_desc1->integer.value <
 674                                     obj_desc2->integer.value))) {
 675                                 temp_obj = elements[j - 1];
 676                                 elements[j - 1] = elements[j];
 677                                 elements[j] = temp_obj;
 678                         }
 679                 }
 680         }
 681
 682         return (AE_OK);
 683 }