release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/acpi/acpica/exstorob.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exstorob - AML Interpreter object store support, store to object
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2010, 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 "acinterp.h"
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50 ACPI_MODULE_NAME("exstorob")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ex_store_buffer_to_buffer
  55  *
  56  * PARAMETERS:  source_desc         - Source object to copy
  57  *              target_desc         - Destination object of the copy
  58  *
  59  * RETURN:      Status
  60  *
  61  * DESCRIPTION: Copy a buffer object to another buffer object.
  62  *
  63  ******************************************************************************/
  64 acpi_status
  65 acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,
  66                                union acpi_operand_object *target_desc)
  67 {
  68         u32 length;
  69         u8 *buffer;
  70
  71         ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);
  72
  73         /* If Source and Target are the same, just return */
  74
  75         if (source_desc == target_desc) {
  76                 return_ACPI_STATUS(AE_OK);
  77         }
  78
  79         /* We know that source_desc is a buffer by now */
  80
  81         buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
  82         length = source_desc->buffer.length;
  83
  84         /*
  85          * If target is a buffer of length zero or is a static buffer,
  86          * allocate a new buffer of the proper length
  87          */
  88         if ((target_desc->buffer.length == 0) ||
  89             (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
  90                 target_desc->buffer.pointer = ACPI_ALLOCATE(length);
  91                 if (!target_desc->buffer.pointer) {
  92                         return_ACPI_STATUS(AE_NO_MEMORY);
  93                 }
  94
  95                 target_desc->buffer.length = length;
  96         }
  97
  98         /* Copy source buffer to target buffer */
  99
 100         if (length <= target_desc->buffer.length) {
 101
 102                 /* Clear existing buffer and copy in the new one */
 103
 104                 ACPI_MEMSET(target_desc->buffer.pointer, 0,
 105                             target_desc->buffer.length);
 106                 ACPI_MEMCPY(target_desc->buffer.pointer, buffer, length);
 107
 108 #ifdef ACPI_OBSOLETE_BEHAVIOR
 109                 /*
 110                  * NOTE: ACPI versions up to 3.0 specified that the buffer must be
 111                  * truncated if the string is smaller than the buffer.  However, "other"
 112                  * implementations of ACPI never did this and thus became the defacto
 113                  * standard. ACPI 3.0_a changes this behavior such that the buffer
 114                  * is no longer truncated.
 115                  */
 116
 117                 /*
 118                  * OBSOLETE BEHAVIOR:
 119                  * If the original source was a string, we must truncate the buffer,
 120                  * according to the ACPI spec.  Integer-to-Buffer and Buffer-to-Buffer
 121                  * copy must not truncate the original buffer.
 122                  */
 123                 if (original_src_type == ACPI_TYPE_STRING) {
 124
 125                         /* Set the new length of the target */
 126
 127                         target_desc->buffer.length = length;
 128                 }
 129 #endif
 130         } else {
 131                 /* Truncate the source, copy only what will fit */
 132
 133                 ACPI_MEMCPY(target_desc->buffer.pointer, buffer,
 134                             target_desc->buffer.length);
 135
 136                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 137                                   "Truncating source buffer from %X to %X\n",
 138                                   length, target_desc->buffer.length));
 139         }
 140
 141         /* Copy flags */
 142
 143         target_desc->buffer.flags = source_desc->buffer.flags;
 144         target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
 145         return_ACPI_STATUS(AE_OK);
 146 }
 147
 148 /*******************************************************************************
 149  *
 150  * FUNCTION:    acpi_ex_store_string_to_string
 151  *
 152  * PARAMETERS:  source_desc         - Source object to copy
 153  *              target_desc         - Destination object of the copy
 154  *
 155  * RETURN:      Status
 156  *
 157  * DESCRIPTION: Copy a String object to another String object
 158  *
 159  ******************************************************************************/
 160
 161 acpi_status
 162 acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
 163                                union acpi_operand_object *target_desc)
 164 {
 165         u32 length;
 166         u8 *buffer;
 167
 168         ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
 169
 170         /* If Source and Target are the same, just return */
 171
 172         if (source_desc == target_desc) {
 173                 return_ACPI_STATUS(AE_OK);
 174         }
 175
 176         /* We know that source_desc is a string by now */
 177
 178         buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
 179         length = source_desc->string.length;
 180
 181         /*
 182          * Replace existing string value if it will fit and the string
 183          * pointer is not a static pointer (part of an ACPI table)
 184          */
 185         if ((length < target_desc->string.length) &&
 186             (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
 187                 /*
 188                  * String will fit in existing non-static buffer.
 189                  * Clear old string and copy in the new one
 190                  */
 191                 ACPI_MEMSET(target_desc->string.pointer, 0,
 192                             (acpi_size) target_desc->string.length + 1);
 193                 ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
 194         } else {
 195                 /*
 196                  * Free the current buffer, then allocate a new buffer
 197                  * large enough to hold the value
 198                  */
 199                 if (target_desc->string.pointer &&
 200                     (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
 201
 202                         /* Only free if not a pointer into the DSDT */
 203
 204                         ACPI_FREE(target_desc->string.pointer);
 205                 }
 206
 207                 target_desc->string.pointer = ACPI_ALLOCATE_ZEROED((acpi_size)
 208                                                                    length + 1);
 209                 if (!target_desc->string.pointer) {
 210                         return_ACPI_STATUS(AE_NO_MEMORY);
 211                 }
 212
 213                 target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
 214                 ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
 215         }
 216
 217         /* Set the new target length */
 218
 219         target_desc->string.length = length;
 220         return_ACPI_STATUS(AE_OK);
 221 }