drivers/acpi/executer/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 - 2005, R. Byron Moore
  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
  46 #include <acpi/acpi.h>
  47 #include <acpi/acinterp.h>
  48
  49
  50 #define _COMPONENT          ACPI_EXECUTER
  51          ACPI_MODULE_NAME    ("exstorob")
  52
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_ex_store_buffer_to_buffer
  57  *
  58  * PARAMETERS:  source_desc         - Source object to copy
  59  *              target_desc         - Destination object of the copy
  60  *
  61  * RETURN:      Status
  62  *
  63  * DESCRIPTION: Copy a buffer object to another buffer object.
  64  *
  65  ******************************************************************************/
  66
  67 acpi_status
  68 acpi_ex_store_buffer_to_buffer (
  69         union acpi_operand_object       *source_desc,
  70         union acpi_operand_object       *target_desc)
  71 {
  72         u32                             length;
  73         u8                              *buffer;
  74
  75
  76         ACPI_FUNCTION_TRACE_PTR ("ex_store_buffer_to_buffer", source_desc);
  77
  78
  79         /* We know that source_desc is a buffer by now */
  80
  81         buffer = (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_MEM_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                 /* Clear existing buffer and copy in the new one */
 102
 103                 ACPI_MEMSET (target_desc->buffer.pointer, 0, target_desc->buffer.length);
 104                 ACPI_MEMCPY (target_desc->buffer.pointer, buffer, length);
 105
 106 #ifdef ACPI_OBSOLETE_BEHAVIOR
 107                 /*
 108                  * NOTE: ACPI versions up to 3.0 specified that the buffer must be
 109                  * truncated if the string is smaller than the buffer.  However, "other"
 110                  * implementations of ACPI never did this and thus became the defacto
 111                  * standard. ACPi 3.0_a changes this behavior such that the buffer
 112                  * is no longer truncated.
 113                  */
 114
 115                 /*
 116                  * OBSOLETE BEHAVIOR:
 117                  * If the original source was a string, we must truncate the buffer,
 118                  * according to the ACPI spec.  Integer-to-Buffer and Buffer-to-Buffer
 119                  * copy must not truncate the original buffer.
 120                  */
 121                 if (original_src_type == ACPI_TYPE_STRING) {
 122                         /* Set the new length of the target */
 123
 124                         target_desc->buffer.length = length;
 125                 }
 126 #endif
 127         }
 128         else {
 129                 /* Truncate the source, copy only what will fit */
 130
 131                 ACPI_MEMCPY (target_desc->buffer.pointer, buffer,
 132                         target_desc->buffer.length);
 133
 134                 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 135                         "Truncating source buffer from %X to %X\n",
 136                         length, target_desc->buffer.length));
 137         }
 138
 139         /* Copy flags */
 140
 141         target_desc->buffer.flags = source_desc->buffer.flags;
 142         target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
 143         return_ACPI_STATUS (AE_OK);
 144 }
 145
 146
 147 /*******************************************************************************
 148  *
 149  * FUNCTION:    acpi_ex_store_string_to_string
 150  *
 151  * PARAMETERS:  source_desc         - Source object to copy
 152  *              target_desc         - Destination object of the copy
 153  *
 154  * RETURN:      Status
 155  *
 156  * DESCRIPTION: Copy a String object to another String object
 157  *
 158  ******************************************************************************/
 159
 160 acpi_status
 161 acpi_ex_store_string_to_string (
 162         union acpi_operand_object       *source_desc,
 163         union acpi_operand_object       *target_desc)
 164 {
 165         u32                             length;
 166         u8                              *buffer;
 167
 168
 169         ACPI_FUNCTION_TRACE_PTR ("ex_store_string_to_string", source_desc);
 170
 171
 172         /* We know that source_desc is a string by now */
 173
 174         buffer = (u8 *) source_desc->string.pointer;
 175         length = source_desc->string.length;
 176
 177         /*
 178          * Replace existing string value if it will fit and the string
 179          * pointer is not a static pointer (part of an ACPI table)
 180          */
 181         if ((length < target_desc->string.length) &&
 182            (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
 183                 /*
 184                  * String will fit in existing non-static buffer.
 185                  * Clear old string and copy in the new one
 186                  */
 187                 ACPI_MEMSET (target_desc->string.pointer, 0,
 188                         (acpi_size) target_desc->string.length + 1);
 189                 ACPI_MEMCPY (target_desc->string.pointer, buffer, length);
 190         }
 191         else {
 192                 /*
 193                  * Free the current buffer, then allocate a new buffer
 194                  * large enough to hold the value
 195                  */
 196                 if (target_desc->string.pointer &&
 197                    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
 198                         /* Only free if not a pointer into the DSDT */
 199
 200                         ACPI_MEM_FREE (target_desc->string.pointer);
 201                 }
 202
 203                 target_desc->string.pointer = ACPI_MEM_CALLOCATE (
 204                                    (acpi_size) length + 1);
 205                 if (!target_desc->string.pointer) {
 206                         return_ACPI_STATUS (AE_NO_MEMORY);
 207                 }
 208
 209                 target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
 210                 ACPI_MEMCPY (target_desc->string.pointer, buffer, length);
 211         }
 212
 213         /* Set the new target length */
 214
 215         target_desc->string.length = length;
 216         return_ACPI_STATUS (AE_OK);
 217 }
 218
 219