linux/drivers/acpi/acpica/nsrepair.c
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   1/******************************************************************************
   2 *
   3 * Module Name: nsrepair - Repair for objects returned by predefined methods
   4 *
   5 *****************************************************************************/
   6
   7/*
   8 * Copyright (C) 2000 - 2013, Intel Corp.
   9 * All rights reserved.
  10 *
  11 * Redistribution and use in source and binary forms, with or without
  12 * modification, are permitted provided that the following conditions
  13 * are met:
  14 * 1. Redistributions of source code must retain the above copyright
  15 *    notice, this list of conditions, and the following disclaimer,
  16 *    without modification.
  17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18 *    substantially similar to the "NO WARRANTY" disclaimer below
  19 *    ("Disclaimer") and any redistribution must be conditioned upon
  20 *    including a substantially similar Disclaimer requirement for further
  21 *    binary redistribution.
  22 * 3. Neither the names of the above-listed copyright holders nor the names
  23 *    of any contributors may be used to endorse or promote products derived
  24 *    from this software without specific prior written permission.
  25 *
  26 * Alternatively, this software may be distributed under the terms of the
  27 * GNU General Public License ("GPL") version 2 as published by the Free
  28 * Software Foundation.
  29 *
  30 * NO WARRANTY
  31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41 * POSSIBILITY OF SUCH DAMAGES.
  42 */
  43
  44#include <acpi/acpi.h>
  45#include "accommon.h"
  46#include "acnamesp.h"
  47#include "acinterp.h"
  48#include "acpredef.h"
  49#include "amlresrc.h"
  50
  51#define _COMPONENT          ACPI_NAMESPACE
  52ACPI_MODULE_NAME("nsrepair")
  53
  54/*******************************************************************************
  55 *
  56 * This module attempts to repair or convert objects returned by the
  57 * predefined methods to an object type that is expected, as per the ACPI
  58 * specification. The need for this code is dictated by the many machines that
  59 * return incorrect types for the standard predefined methods. Performing these
  60 * conversions here, in one place, eliminates the need for individual ACPI
  61 * device drivers to do the same. Note: Most of these conversions are different
  62 * than the internal object conversion routines used for implicit object
  63 * conversion.
  64 *
  65 * The following conversions can be performed as necessary:
  66 *
  67 * Integer -> String
  68 * Integer -> Buffer
  69 * String  -> Integer
  70 * String  -> Buffer
  71 * Buffer  -> Integer
  72 * Buffer  -> String
  73 * Buffer  -> Package of Integers
  74 * Package -> Package of one Package
  75 *
  76 * Additional conversions that are available:
  77 *  Convert a null return or zero return value to an end_tag descriptor
  78 *  Convert an ASCII string to a Unicode buffer
  79 *
  80 * An incorrect standalone object is wrapped with required outer package
  81 *
  82 * Additional possible repairs:
  83 * Required package elements that are NULL replaced by Integer/String/Buffer
  84 *
  85 ******************************************************************************/
  86/* Local prototypes */
  87static const struct acpi_simple_repair_info *acpi_ns_match_simple_repair(struct
  88                                                                         acpi_namespace_node
  89                                                                         *node,
  90                                                                         u32
  91                                                                         return_btype,
  92                                                                         u32
  93                                                                         package_index);
  94
  95/*
  96 * Special but simple repairs for some names.
  97 *
  98 * 2nd argument: Unexpected types that can be repaired
  99 */
 100static const struct acpi_simple_repair_info acpi_object_repair_info[] = {
 101        /* Resource descriptor conversions */
 102
 103        {"_CRS",
 104         ACPI_RTYPE_INTEGER | ACPI_RTYPE_STRING | ACPI_RTYPE_BUFFER |
 105         ACPI_RTYPE_NONE,
 106         ACPI_NOT_PACKAGE_ELEMENT,
 107         acpi_ns_convert_to_resource},
 108        {"_DMA",
 109         ACPI_RTYPE_INTEGER | ACPI_RTYPE_STRING | ACPI_RTYPE_BUFFER |
 110         ACPI_RTYPE_NONE,
 111         ACPI_NOT_PACKAGE_ELEMENT,
 112         acpi_ns_convert_to_resource},
 113        {"_PRS",
 114         ACPI_RTYPE_INTEGER | ACPI_RTYPE_STRING | ACPI_RTYPE_BUFFER |
 115         ACPI_RTYPE_NONE,
 116         ACPI_NOT_PACKAGE_ELEMENT,
 117         acpi_ns_convert_to_resource},
 118
 119        /* Unicode conversions */
 120
 121        {"_MLS", ACPI_RTYPE_STRING, 1,
 122         acpi_ns_convert_to_unicode},
 123        {"_STR", ACPI_RTYPE_STRING | ACPI_RTYPE_BUFFER,
 124         ACPI_NOT_PACKAGE_ELEMENT,
 125         acpi_ns_convert_to_unicode},
 126        {{0, 0, 0, 0}, 0, 0, NULL}      /* Table terminator */
 127};
 128
 129/*******************************************************************************
 130 *
 131 * FUNCTION:    acpi_ns_simple_repair
 132 *
 133 * PARAMETERS:  info                - Method execution information block
 134 *              expected_btypes     - Object types expected
 135 *              package_index       - Index of object within parent package (if
 136 *                                    applicable - ACPI_NOT_PACKAGE_ELEMENT
 137 *                                    otherwise)
 138 *              return_object_ptr   - Pointer to the object returned from the
 139 *                                    evaluation of a method or object
 140 *
 141 * RETURN:      Status. AE_OK if repair was successful.
 142 *
 143 * DESCRIPTION: Attempt to repair/convert a return object of a type that was
 144 *              not expected.
 145 *
 146 ******************************************************************************/
 147
 148acpi_status
 149acpi_ns_simple_repair(struct acpi_evaluate_info *info,
 150                      u32 expected_btypes,
 151                      u32 package_index,
 152                      union acpi_operand_object **return_object_ptr)
 153{
 154        union acpi_operand_object *return_object = *return_object_ptr;
 155        union acpi_operand_object *new_object = NULL;
 156        acpi_status status;
 157        const struct acpi_simple_repair_info *predefined;
 158
 159        ACPI_FUNCTION_NAME(ns_simple_repair);
 160
 161        /*
 162         * Special repairs for certain names that are in the repair table.
 163         * Check if this name is in the list of repairable names.
 164         */
 165        predefined = acpi_ns_match_simple_repair(info->node,
 166                                                 info->return_btype,
 167                                                 package_index);
 168        if (predefined) {
 169                if (!return_object) {
 170                        ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
 171                                              ACPI_WARN_ALWAYS,
 172                                              "Missing expected return value"));
 173                }
 174
 175                status =
 176                    predefined->object_converter(return_object, &new_object);
 177                if (ACPI_FAILURE(status)) {
 178
 179                        /* A fatal error occurred during a conversion */
 180
 181                        ACPI_EXCEPTION((AE_INFO, status,
 182                                        "During return object analysis"));
 183                        return (status);
 184                }
 185                if (new_object) {
 186                        goto object_repaired;
 187                }
 188        }
 189
 190        /*
 191         * Do not perform simple object repair unless the return type is not
 192         * expected.
 193         */
 194        if (info->return_btype & expected_btypes) {
 195                return (AE_OK);
 196        }
 197
 198        /*
 199         * At this point, we know that the type of the returned object was not
 200         * one of the expected types for this predefined name. Attempt to
 201         * repair the object by converting it to one of the expected object
 202         * types for this predefined name.
 203         */
 204
 205        /*
 206         * If there is no return value, check if we require a return value for
 207         * this predefined name. Either one return value is expected, or none,
 208         * for both methods and other objects.
 209         *
 210         * Exit now if there is no return object. Warning if one was expected.
 211         */
 212        if (!return_object) {
 213                if (expected_btypes && (!(expected_btypes & ACPI_RTYPE_NONE))) {
 214                        ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
 215                                              ACPI_WARN_ALWAYS,
 216                                              "Missing expected return value"));
 217
 218                        return (AE_AML_NO_RETURN_VALUE);
 219                }
 220        }
 221
 222        if (expected_btypes & ACPI_RTYPE_INTEGER) {
 223                status = acpi_ns_convert_to_integer(return_object, &new_object);
 224                if (ACPI_SUCCESS(status)) {
 225                        goto object_repaired;
 226                }
 227        }
 228        if (expected_btypes & ACPI_RTYPE_STRING) {
 229                status = acpi_ns_convert_to_string(return_object, &new_object);
 230                if (ACPI_SUCCESS(status)) {
 231                        goto object_repaired;
 232                }
 233        }
 234        if (expected_btypes & ACPI_RTYPE_BUFFER) {
 235                status = acpi_ns_convert_to_buffer(return_object, &new_object);
 236                if (ACPI_SUCCESS(status)) {
 237                        goto object_repaired;
 238                }
 239        }
 240        if (expected_btypes & ACPI_RTYPE_PACKAGE) {
 241                /*
 242                 * A package is expected. We will wrap the existing object with a
 243                 * new package object. It is often the case that if a variable-length
 244                 * package is required, but there is only a single object needed, the
 245                 * BIOS will return that object instead of wrapping it with a Package
 246                 * object. Note: after the wrapping, the package will be validated
 247                 * for correct contents (expected object type or types).
 248                 */
 249                status =
 250                    acpi_ns_wrap_with_package(info, return_object, &new_object);
 251                if (ACPI_SUCCESS(status)) {
 252                        /*
 253                         * The original object just had its reference count
 254                         * incremented for being inserted into the new package.
 255                         */
 256                        *return_object_ptr = new_object;        /* New Package object */
 257                        info->return_flags |= ACPI_OBJECT_REPAIRED;
 258                        return (AE_OK);
 259                }
 260        }
 261
 262        /* We cannot repair this object */
 263
 264        return (AE_AML_OPERAND_TYPE);
 265
 266object_repaired:
 267
 268        /* Object was successfully repaired */
 269
 270        if (package_index != ACPI_NOT_PACKAGE_ELEMENT) {
 271                /*
 272                 * The original object is a package element. We need to
 273                 * decrement the reference count of the original object,
 274                 * for removing it from the package.
 275                 *
 276                 * However, if the original object was just wrapped with a
 277                 * package object as part of the repair, we don't need to
 278                 * change the reference count.
 279                 */
 280                if (!(info->return_flags & ACPI_OBJECT_WRAPPED)) {
 281                        new_object->common.reference_count =
 282                            return_object->common.reference_count;
 283
 284                        if (return_object->common.reference_count > 1) {
 285                                return_object->common.reference_count--;
 286                        }
 287                }
 288
 289                ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
 290                                  "%s: Converted %s to expected %s at Package index %u\n",
 291                                  info->full_pathname,
 292                                  acpi_ut_get_object_type_name(return_object),
 293                                  acpi_ut_get_object_type_name(new_object),
 294                                  package_index));
 295        } else {
 296                ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
 297                                  "%s: Converted %s to expected %s\n",
 298                                  info->full_pathname,
 299                                  acpi_ut_get_object_type_name(return_object),
 300                                  acpi_ut_get_object_type_name(new_object)));
 301        }
 302
 303        /* Delete old object, install the new return object */
 304
 305        acpi_ut_remove_reference(return_object);
 306        *return_object_ptr = new_object;
 307        info->return_flags |= ACPI_OBJECT_REPAIRED;
 308        return (AE_OK);
 309}
 310
 311/******************************************************************************
 312 *
 313 * FUNCTION:    acpi_ns_match_simple_repair
 314 *
 315 * PARAMETERS:  node                - Namespace node for the method/object
 316 *              return_btype        - Object type that was returned
 317 *              package_index       - Index of object within parent package (if
 318 *                                    applicable - ACPI_NOT_PACKAGE_ELEMENT
 319 *                                    otherwise)
 320 *
 321 * RETURN:      Pointer to entry in repair table. NULL indicates not found.
 322 *
 323 * DESCRIPTION: Check an object name against the repairable object list.
 324 *
 325 *****************************************************************************/
 326
 327static const struct acpi_simple_repair_info *acpi_ns_match_simple_repair(struct
 328                                                                         acpi_namespace_node
 329                                                                         *node,
 330                                                                         u32
 331                                                                         return_btype,
 332                                                                         u32
 333                                                                         package_index)
 334{
 335        const struct acpi_simple_repair_info *this_name;
 336
 337        /* Search info table for a repairable predefined method/object name */
 338
 339        this_name = acpi_object_repair_info;
 340        while (this_name->object_converter) {
 341                if (ACPI_COMPARE_NAME(node->name.ascii, this_name->name)) {
 342
 343                        /* Check if we can actually repair this name/type combination */
 344
 345                        if ((return_btype & this_name->unexpected_btypes) &&
 346                            (package_index == this_name->package_index)) {
 347                                return (this_name);
 348                        }
 349
 350                        return (NULL);
 351                }
 352                this_name++;
 353        }
 354
 355        return (NULL);          /* Name was not found in the repair table */
 356}
 357
 358/*******************************************************************************
 359 *
 360 * FUNCTION:    acpi_ns_repair_null_element
 361 *
 362 * PARAMETERS:  info                - Method execution information block
 363 *              expected_btypes     - Object types expected
 364 *              package_index       - Index of object within parent package (if
 365 *                                    applicable - ACPI_NOT_PACKAGE_ELEMENT
 366 *                                    otherwise)
 367 *              return_object_ptr   - Pointer to the object returned from the
 368 *                                    evaluation of a method or object
 369 *
 370 * RETURN:      Status. AE_OK if repair was successful.
 371 *
 372 * DESCRIPTION: Attempt to repair a NULL element of a returned Package object.
 373 *
 374 ******************************************************************************/
 375
 376acpi_status
 377acpi_ns_repair_null_element(struct acpi_evaluate_info * info,
 378                            u32 expected_btypes,
 379                            u32 package_index,
 380                            union acpi_operand_object **return_object_ptr)
 381{
 382        union acpi_operand_object *return_object = *return_object_ptr;
 383        union acpi_operand_object *new_object;
 384
 385        ACPI_FUNCTION_NAME(ns_repair_null_element);
 386
 387        /* No repair needed if return object is non-NULL */
 388
 389        if (return_object) {
 390                return (AE_OK);
 391        }
 392
 393        /*
 394         * Attempt to repair a NULL element of a Package object. This applies to
 395         * predefined names that return a fixed-length package and each element
 396         * is required. It does not apply to variable-length packages where NULL
 397         * elements are allowed, especially at the end of the package.
 398         */
 399        if (expected_btypes & ACPI_RTYPE_INTEGER) {
 400
 401                /* Need an integer - create a zero-value integer */
 402
 403                new_object = acpi_ut_create_integer_object((u64)0);
 404        } else if (expected_btypes & ACPI_RTYPE_STRING) {
 405
 406                /* Need a string - create a NULL string */
 407
 408                new_object = acpi_ut_create_string_object(0);
 409        } else if (expected_btypes & ACPI_RTYPE_BUFFER) {
 410
 411                /* Need a buffer - create a zero-length buffer */
 412
 413                new_object = acpi_ut_create_buffer_object(0);
 414        } else {
 415                /* Error for all other expected types */
 416
 417                return (AE_AML_OPERAND_TYPE);
 418        }
 419
 420        if (!new_object) {
 421                return (AE_NO_MEMORY);
 422        }
 423
 424        /* Set the reference count according to the parent Package object */
 425
 426        new_object->common.reference_count =
 427            info->parent_package->common.reference_count;
 428
 429        ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
 430                          "%s: Converted NULL package element to expected %s at index %u\n",
 431                          info->full_pathname,
 432                          acpi_ut_get_object_type_name(new_object),
 433                          package_index));
 434
 435        *return_object_ptr = new_object;
 436        info->return_flags |= ACPI_OBJECT_REPAIRED;
 437        return (AE_OK);
 438}
 439
 440/******************************************************************************
 441 *
 442 * FUNCTION:    acpi_ns_remove_null_elements
 443 *
 444 * PARAMETERS:  info                - Method execution information block
 445 *              package_type        - An acpi_return_package_types value
 446 *              obj_desc            - A Package object
 447 *
 448 * RETURN:      None.
 449 *
 450 * DESCRIPTION: Remove all NULL package elements from packages that contain
 451 *              a variable number of sub-packages. For these types of
 452 *              packages, NULL elements can be safely removed.
 453 *
 454 *****************************************************************************/
 455
 456void
 457acpi_ns_remove_null_elements(struct acpi_evaluate_info *info,
 458                             u8 package_type,
 459                             union acpi_operand_object *obj_desc)
 460{
 461        union acpi_operand_object **source;
 462        union acpi_operand_object **dest;
 463        u32 count;
 464        u32 new_count;
 465        u32 i;
 466
 467        ACPI_FUNCTION_NAME(ns_remove_null_elements);
 468
 469        /*
 470         * We can safely remove all NULL elements from these package types:
 471         * PTYPE1_VAR packages contain a variable number of simple data types.
 472         * PTYPE2 packages contain a variable number of sub-packages.
 473         */
 474        switch (package_type) {
 475        case ACPI_PTYPE1_VAR:
 476        case ACPI_PTYPE2:
 477        case ACPI_PTYPE2_COUNT:
 478        case ACPI_PTYPE2_PKG_COUNT:
 479        case ACPI_PTYPE2_FIXED:
 480        case ACPI_PTYPE2_MIN:
 481        case ACPI_PTYPE2_REV_FIXED:
 482        case ACPI_PTYPE2_FIX_VAR:
 483
 484                break;
 485
 486        default:
 487        case ACPI_PTYPE1_FIXED:
 488        case ACPI_PTYPE1_OPTION:
 489                return;
 490        }
 491
 492        count = obj_desc->package.count;
 493        new_count = count;
 494
 495        source = obj_desc->package.elements;
 496        dest = source;
 497
 498        /* Examine all elements of the package object, remove nulls */
 499
 500        for (i = 0; i < count; i++) {
 501                if (!*source) {
 502                        new_count--;
 503                } else {
 504                        *dest = *source;
 505                        dest++;
 506                }
 507                source++;
 508        }
 509
 510        /* Update parent package if any null elements were removed */
 511
 512        if (new_count < count) {
 513                ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
 514                                  "%s: Found and removed %u NULL elements\n",
 515                                  info->full_pathname, (count - new_count)));
 516
 517                /* NULL terminate list and update the package count */
 518
 519                *dest = NULL;
 520                obj_desc->package.count = new_count;
 521        }
 522}
 523
 524/*******************************************************************************
 525 *
 526 * FUNCTION:    acpi_ns_wrap_with_package
 527 *
 528 * PARAMETERS:  info                - Method execution information block
 529 *              original_object     - Pointer to the object to repair.
 530 *              obj_desc_ptr        - The new package object is returned here
 531 *
 532 * RETURN:      Status, new object in *obj_desc_ptr
 533 *
 534 * DESCRIPTION: Repair a common problem with objects that are defined to
 535 *              return a variable-length Package of sub-objects. If there is
 536 *              only one sub-object, some BIOS code mistakenly simply declares
 537 *              the single object instead of a Package with one sub-object.
 538 *              This function attempts to repair this error by wrapping a
 539 *              Package object around the original object, creating the
 540 *              correct and expected Package with one sub-object.
 541 *
 542 *              Names that can be repaired in this manner include:
 543 *              _ALR, _CSD, _HPX, _MLS, _PLD, _PRT, _PSS, _TRT, _TSS,
 544 *              _BCL, _DOD, _FIX, _Sx
 545 *
 546 ******************************************************************************/
 547
 548acpi_status
 549acpi_ns_wrap_with_package(struct acpi_evaluate_info *info,
 550                          union acpi_operand_object *original_object,
 551                          union acpi_operand_object **obj_desc_ptr)
 552{
 553        union acpi_operand_object *pkg_obj_desc;
 554
 555        ACPI_FUNCTION_NAME(ns_wrap_with_package);
 556
 557        /*
 558         * Create the new outer package and populate it. The new package will
 559         * have a single element, the lone sub-object.
 560         */
 561        pkg_obj_desc = acpi_ut_create_package_object(1);
 562        if (!pkg_obj_desc) {
 563                return (AE_NO_MEMORY);
 564        }
 565
 566        pkg_obj_desc->package.elements[0] = original_object;
 567
 568        ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
 569                          "%s: Wrapped %s with expected Package object\n",
 570                          info->full_pathname,
 571                          acpi_ut_get_object_type_name(original_object)));
 572
 573        /* Return the new object in the object pointer */
 574
 575        *obj_desc_ptr = pkg_obj_desc;
 576        info->return_flags |= ACPI_OBJECT_REPAIRED | ACPI_OBJECT_WRAPPED;
 577        return (AE_OK);
 578}
 579