drivers/acpi/acpica/nsrepair.c

   1 /******************************************************************************
   2  *
   3  * Module Name: nsrepair - Repair for objects returned by predefined methods
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2009, 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 "acpredef.h"
  48
  49 #define _COMPONENT          ACPI_NAMESPACE
  50 ACPI_MODULE_NAME("nsrepair")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ns_repair_object
  55  *
  56  * PARAMETERS:  Data                - Pointer to validation data structure
  57  *              expected_btypes     - Object types expected
  58  *              package_index       - Index of object within parent package (if
  59  *                                    applicable - ACPI_NOT_PACKAGE_ELEMENT
  60  *                                    otherwise)
  61  *              return_object_ptr   - Pointer to the object returned from the
  62  *                                    evaluation of a method or object
  63  *
  64  * RETURN:      Status. AE_OK if repair was successful.
  65  *
  66  * DESCRIPTION: Attempt to repair/convert a return object of a type that was
  67  *              not expected.
  68  *
  69  ******************************************************************************/
  70 acpi_status
  71 acpi_ns_repair_object(struct acpi_predefined_data *data,
  72                       u32 expected_btypes,
  73                       u32 package_index,
  74                       union acpi_operand_object **return_object_ptr)
  75 {
  76         union acpi_operand_object *return_object = *return_object_ptr;
  77         union acpi_operand_object *new_object;
  78         acpi_size length;
  79
  80         /*
  81          * At this point, we know that the type of the returned object was not
  82          * one of the expected types for this predefined name. Attempt to
  83          * repair the object. Only a limited number of repairs are possible.
  84          */
  85         switch (return_object->common.type) {
  86         case ACPI_TYPE_BUFFER:
  87
  88                 /* Does the method/object legally return a string? */
  89
  90                 if (!(expected_btypes & ACPI_RTYPE_STRING)) {
  91                         return (AE_AML_OPERAND_TYPE);
  92                 }
  93
  94                 /*
  95                  * Have a Buffer, expected a String, convert. Use a to_string
  96                  * conversion, no transform performed on the buffer data. The best
  97                  * example of this is the _BIF method, where the string data from
  98                  * the battery is often (incorrectly) returned as buffer object(s).
  99                  */
 100                 length = 0;
 101                 while ((length < return_object->buffer.length) &&
 102                        (return_object->buffer.pointer[length])) {
 103                         length++;
 104                 }
 105
 106                 /* Allocate a new string object */
 107
 108                 new_object = acpi_ut_create_string_object(length);
 109                 if (!new_object) {
 110                         return (AE_NO_MEMORY);
 111                 }
 112
 113                 /*
 114                  * Copy the raw buffer data with no transform. String is already NULL
 115                  * terminated at Length+1.
 116                  */
 117                 ACPI_MEMCPY(new_object->string.pointer,
 118                             return_object->buffer.pointer, length);
 119                 break;
 120
 121         case ACPI_TYPE_INTEGER:
 122
 123                 /* Does the method/object legally return a string? */
 124
 125                 if (expected_btypes & ACPI_RTYPE_STRING) {
 126                         /*
 127                          * The only supported Integer-to-String conversion is to convert
 128                          * an integer of value 0 to a NULL string. The last element of
 129                          * _BIF and _BIX packages occasionally need this fix.
 130                          */
 131                         if (return_object->integer.value != 0) {
 132                                 return (AE_AML_OPERAND_TYPE);
 133                         }
 134
 135                         /* Allocate a new NULL string object */
 136
 137                         new_object = acpi_ut_create_string_object(0);
 138                         if (!new_object) {
 139                                 return (AE_NO_MEMORY);
 140                         }
 141                 } else {
 142                         return (AE_AML_OPERAND_TYPE);
 143                 }
 144                 break;
 145
 146         default:
 147
 148                 /* We cannot repair this object */
 149
 150                 return (AE_AML_OPERAND_TYPE);
 151         }
 152
 153         /* Object was successfully repaired */
 154
 155         /*
 156          * If the original object is a package element, we need to:
 157          * 1. Set the reference count of the new object to match the
 158          *    reference count of the old object.
 159          * 2. Decrement the reference count of the original object.
 160          */
 161         if (package_index != ACPI_NOT_PACKAGE_ELEMENT) {
 162                 new_object->common.reference_count =
 163                     return_object->common.reference_count;
 164
 165                 if (return_object->common.reference_count > 1) {
 166                         return_object->common.reference_count--;
 167                 }
 168
 169                 ACPI_WARN_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 170                                       "Converted %s to expected %s at index %u",
 171                                       acpi_ut_get_object_type_name
 172                                       (return_object),
 173                                       acpi_ut_get_object_type_name(new_object),
 174                                       package_index));
 175         } else {
 176                 ACPI_WARN_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 177                                       "Converted %s to expected %s",
 178                                       acpi_ut_get_object_type_name
 179                                       (return_object),
 180                                       acpi_ut_get_object_type_name
 181                                       (new_object)));
 182         }
 183
 184         /* Delete old object, install the new return object */
 185
 186         acpi_ut_remove_reference(return_object);
 187         *return_object_ptr = new_object;
 188         data->flags |= ACPI_OBJECT_REPAIRED;
 189         return (AE_OK);
 190 }
 191
 192 /*******************************************************************************
 193  *
 194  * FUNCTION:    acpi_ns_repair_package_list
 195  *
 196  * PARAMETERS:  Data                - Pointer to validation data structure
 197  *              obj_desc_ptr        - Pointer to the object to repair. The new
 198  *                                    package object is returned here,
 199  *                                    overwriting the old object.
 200  *
 201  * RETURN:      Status, new object in *obj_desc_ptr
 202  *
 203  * DESCRIPTION: Repair a common problem with objects that are defined to return
 204  *              a variable-length Package of Packages. If the variable-length
 205  *              is one, some BIOS code mistakenly simply declares a single
 206  *              Package instead of a Package with one sub-Package. This
 207  *              function attempts to repair this error by wrapping a Package
 208  *              object around the original Package, creating the correct
 209  *              Package with one sub-Package.
 210  *
 211  *              Names that can be repaired in this manner include:
 212  *              _ALR, _CSD, _HPX, _MLS, _PRT, _PSS, _TRT, TSS
 213  *
 214  ******************************************************************************/
 215
 216 acpi_status
 217 acpi_ns_repair_package_list(struct acpi_predefined_data *data,
 218                             union acpi_operand_object **obj_desc_ptr)
 219 {
 220         union acpi_operand_object *pkg_obj_desc;
 221
 222         /*
 223          * Create the new outer package and populate it. The new package will
 224          * have a single element, the lone subpackage.
 225          */
 226         pkg_obj_desc = acpi_ut_create_package_object(1);
 227         if (!pkg_obj_desc) {
 228                 return (AE_NO_MEMORY);
 229         }
 230
 231         pkg_obj_desc->package.elements[0] = *obj_desc_ptr;
 232
 233         /* Return the new object in the object pointer */
 234
 235         *obj_desc_ptr = pkg_obj_desc;
 236         data->flags |= ACPI_OBJECT_REPAIRED;
 237
 238         ACPI_WARN_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 239                               "Incorrectly formed Package, attempting repair"));
 240
 241         return (AE_OK);
 242 }