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 - 2008, 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 <acpi/accommon.h>
  47 #include <acpi/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         /* We know that source_desc is a buffer by now */
  74
  75         buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
  76         length = source_desc->buffer.length;
  77
  78         /*
  79          * If target is a buffer of length zero or is a static buffer,
  80          * allocate a new buffer of the proper length
  81          */
  82         if ((target_desc->buffer.length == 0) ||
  83             (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
  84                 target_desc->buffer.pointer = ACPI_ALLOCATE(length);
  85                 if (!target_desc->buffer.pointer) {
  86                         return_ACPI_STATUS(AE_NO_MEMORY);
  87                 }
  88
  89                 target_desc->buffer.length = length;
  90         }
  91
  92         /* Copy source buffer to target buffer */
  93
  94         if (length <= target_desc->buffer.length) {
  95
  96                 /* Clear existing buffer and copy in the new one */
  97
  98                 ACPI_MEMSET(target_desc->buffer.pointer, 0,
  99                             target_desc->buffer.length);
 100                 ACPI_MEMCPY(target_desc->buffer.pointer, buffer, length);
 101
 102 #ifdef ACPI_OBSOLETE_BEHAVIOR
 103                 /*
 104                  * NOTE: ACPI versions up to 3.0 specified that the buffer must be
 105                  * truncated if the string is smaller than the buffer.  However, "other"
 106                  * implementations of ACPI never did this and thus became the defacto
 107                  * standard. ACPI 3.0_a changes this behavior such that the buffer
 108                  * is no longer truncated.
 109                  */
 110
 111                 /*
 112                  * OBSOLETE BEHAVIOR:
 113                  * If the original source was a string, we must truncate the buffer,
 114                  * according to the ACPI spec.  Integer-to-Buffer and Buffer-to-Buffer
 115                  * copy must not truncate the original buffer.
 116                  */
 117                 if (original_src_type == ACPI_TYPE_STRING) {
 118
 119                         /* Set the new length of the target */
 120
 121                         target_desc->buffer.length = length;
 122                 }
 123 #endif
 124         } else {
 125                 /* Truncate the source, copy only what will fit */
 126
 127                 ACPI_MEMCPY(target_desc->buffer.pointer, buffer,
 128                             target_desc->buffer.length);
 129
 130                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 131                                   "Truncating source buffer from %X to %X\n",
 132                                   length, target_desc->buffer.length));
 133         }
 134
 135         /* Copy flags */
 136
 137         target_desc->buffer.flags = source_desc->buffer.flags;
 138         target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
 139         return_ACPI_STATUS(AE_OK);
 140 }
 141
 142 /*******************************************************************************
 143  *
 144  * FUNCTION:    acpi_ex_store_string_to_string
 145  *
 146  * PARAMETERS:  source_desc         - Source object to copy
 147  *              target_desc         - Destination object of the copy
 148  *
 149  * RETURN:      Status
 150  *
 151  * DESCRIPTION: Copy a String object to another String object
 152  *
 153  ******************************************************************************/
 154
 155 acpi_status
 156 acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
 157                                union acpi_operand_object *target_desc)
 158 {
 159         u32 length;
 160         u8 *buffer;
 161
 162         ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
 163
 164         /* We know that source_desc is a string by now */
 165
 166         buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
 167         length = source_desc->string.length;
 168
 169         /*
 170          * Replace existing string value if it will fit and the string
 171          * pointer is not a static pointer (part of an ACPI table)
 172          */
 173         if ((length < target_desc->string.length) &&
 174             (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
 175                 /*
 176                  * String will fit in existing non-static buffer.
 177                  * Clear old string and copy in the new one
 178                  */
 179                 ACPI_MEMSET(target_desc->string.pointer, 0,
 180                             (acpi_size) target_desc->string.length + 1);
 181                 ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
 182         } else {
 183                 /*
 184                  * Free the current buffer, then allocate a new buffer
 185                  * large enough to hold the value
 186                  */
 187                 if (target_desc->string.pointer &&
 188                     (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
 189
 190                         /* Only free if not a pointer into the DSDT */
 191
 192                         ACPI_FREE(target_desc->string.pointer);
 193                 }
 194
 195                 target_desc->string.pointer = ACPI_ALLOCATE_ZEROED((acpi_size)
 196                                                                    length + 1);
 197                 if (!target_desc->string.pointer) {
 198                         return_ACPI_STATUS(AE_NO_MEMORY);
 199                 }
 200
 201                 target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
 202                 ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
 203         }
 204
 205         /* Set the new target length */
 206
 207         target_desc->string.length = length;
 208         return_ACPI_STATUS(AE_OK);
 209 }