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 - 2007, 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 #include <acpi/acpi.h>
  46 #include <acpi/acinterp.h>
  47
  48 #define _COMPONENT          ACPI_EXECUTER
  49 ACPI_MODULE_NAME("exstorob")
  50
  51 /*******************************************************************************
  52  *
  53  * FUNCTION:    acpi_ex_store_buffer_to_buffer
  54  *
  55  * PARAMETERS:  source_desc         - Source object to copy
  56  *              target_desc         - Destination object of the copy
  57  *
  58  * RETURN:      Status
  59  *
  60  * DESCRIPTION: Copy a buffer object to another buffer object.
  61  *
  62  ******************************************************************************/
  63 acpi_status
  64 acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,
  65                                union acpi_operand_object *target_desc)
  66 {
  67         u32 length;
  68         u8 *buffer;
  69
  70         ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);
  71
  72         /* We know that source_desc is a buffer by now */
  73
  74         buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
  75         length = source_desc->buffer.length;
  76
  77         /*
  78          * If target is a buffer of length zero or is a static buffer,
  79          * allocate a new buffer of the proper length
  80          */
  81         if ((target_desc->buffer.length == 0) ||
  82             (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
  83                 target_desc->buffer.pointer = ACPI_ALLOCATE(length);
  84                 if (!target_desc->buffer.pointer) {
  85                         return_ACPI_STATUS(AE_NO_MEMORY);
  86                 }
  87
  88                 target_desc->buffer.length = length;
  89         }
  90
  91         /* Copy source buffer to target buffer */
  92
  93         if (length <= target_desc->buffer.length) {
  94
  95                 /* Clear existing buffer and copy in the new one */
  96
  97                 ACPI_MEMSET(target_desc->buffer.pointer, 0,
  98                             target_desc->buffer.length);
  99                 ACPI_MEMCPY(target_desc->buffer.pointer, buffer, length);
 100
 101 #ifdef ACPI_OBSOLETE_BEHAVIOR
 102                 /*
 103                  * NOTE: ACPI versions up to 3.0 specified that the buffer must be
 104                  * truncated if the string is smaller than the buffer.  However, "other"
 105                  * implementations of ACPI never did this and thus became the defacto
 106                  * standard. ACPI 3.0_a changes this behavior such that the buffer
 107                  * is no longer truncated.
 108                  */
 109
 110                 /*
 111                  * OBSOLETE BEHAVIOR:
 112                  * If the original source was a string, we must truncate the buffer,
 113                  * according to the ACPI spec.  Integer-to-Buffer and Buffer-to-Buffer
 114                  * copy must not truncate the original buffer.
 115                  */
 116                 if (original_src_type == ACPI_TYPE_STRING) {
 117
 118                         /* Set the new length of the target */
 119
 120                         target_desc->buffer.length = length;
 121                 }
 122 #endif
 123         } else {
 124                 /* Truncate the source, copy only what will fit */
 125
 126                 ACPI_MEMCPY(target_desc->buffer.pointer, buffer,
 127                             target_desc->buffer.length);
 128
 129                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 130                                   "Truncating source buffer from %X to %X\n",
 131                                   length, target_desc->buffer.length));
 132         }
 133
 134         /* Copy flags */
 135
 136         target_desc->buffer.flags = source_desc->buffer.flags;
 137         target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
 138         return_ACPI_STATUS(AE_OK);
 139 }
 140
 141 /*******************************************************************************
 142  *
 143  * FUNCTION:    acpi_ex_store_string_to_string
 144  *
 145  * PARAMETERS:  source_desc         - Source object to copy
 146  *              target_desc         - Destination object of the copy
 147  *
 148  * RETURN:      Status
 149  *
 150  * DESCRIPTION: Copy a String object to another String object
 151  *
 152  ******************************************************************************/
 153
 154 acpi_status
 155 acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
 156                                union acpi_operand_object *target_desc)
 157 {
 158         u32 length;
 159         u8 *buffer;
 160
 161         ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
 162
 163         /* We know that source_desc is a string by now */
 164
 165         buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
 166         length = source_desc->string.length;
 167
 168         /*
 169          * Replace existing string value if it will fit and the string
 170          * pointer is not a static pointer (part of an ACPI table)
 171          */
 172         if ((length < target_desc->string.length) &&
 173             (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
 174                 /*
 175                  * String will fit in existing non-static buffer.
 176                  * Clear old string and copy in the new one
 177                  */
 178                 ACPI_MEMSET(target_desc->string.pointer, 0,
 179                             (acpi_size) target_desc->string.length + 1);
 180                 ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
 181         } else {
 182                 /*
 183                  * Free the current buffer, then allocate a new buffer
 184                  * large enough to hold the value
 185                  */
 186                 if (target_desc->string.pointer &&
 187                     (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
 188
 189                         /* Only free if not a pointer into the DSDT */
 190
 191                         ACPI_FREE(target_desc->string.pointer);
 192                 }
 193
 194                 target_desc->string.pointer = ACPI_ALLOCATE_ZEROED((acpi_size)
 195                                                                    length + 1);
 196                 if (!target_desc->string.pointer) {
 197                         return_ACPI_STATUS(AE_NO_MEMORY);
 198                 }
 199
 200                 target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
 201                 ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
 202         }
 203
 204         /* Set the new target length */
 205
 206         target_desc->string.length = length;
 207         return_ACPI_STATUS(AE_OK);
 208 }