drivers/bus/acpi/acpica/executer/exstorob.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exstorob - AML object store support, store to object
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2018, 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.h"
  45 #include "accommon.h"
  46 #include "acinterp.h"
  47
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50         ACPI_MODULE_NAME    ("exstorob")
  51
  52
  53 /*******************************************************************************
  54  *
  55  * FUNCTION:    AcpiExStoreBufferToBuffer
  56  *
  57  * PARAMETERS:  SourceDesc          - Source object to copy
  58  *              TargetDesc          - Destination object of the copy
  59  *
  60  * RETURN:      Status
  61  *
  62  * DESCRIPTION: Copy a buffer object to another buffer object.
  63  *
  64  ******************************************************************************/
  65
  66 ACPI_STATUS
  67 AcpiExStoreBufferToBuffer (
  68     ACPI_OPERAND_OBJECT     *SourceDesc,
  69     ACPI_OPERAND_OBJECT     *TargetDesc)
  70 {
  71     UINT32                  Length;
  72     UINT8                   *Buffer;
  73
  74
  75     ACPI_FUNCTION_TRACE_PTR (ExStoreBufferToBuffer, SourceDesc);
  76
  77
  78     /* If Source and Target are the same, just return */
  79
  80     if (SourceDesc == TargetDesc)
  81     {
  82         return_ACPI_STATUS (AE_OK);
  83     }
  84
  85     /* We know that SourceDesc is a buffer by now */
  86
  87     Buffer = ACPI_CAST_PTR (UINT8, SourceDesc->Buffer.Pointer);
  88     Length = SourceDesc->Buffer.Length;
  89
  90     /*
  91      * If target is a buffer of length zero or is a static buffer,
  92      * allocate a new buffer of the proper length
  93      */
  94     if ((TargetDesc->Buffer.Length == 0) ||
  95         (TargetDesc->Common.Flags & AOPOBJ_STATIC_POINTER))
  96     {
  97         TargetDesc->Buffer.Pointer = ACPI_ALLOCATE (Length);
  98         if (!TargetDesc->Buffer.Pointer)
  99         {
 100             return_ACPI_STATUS (AE_NO_MEMORY);
 101         }
 102
 103         TargetDesc->Buffer.Length = Length;
 104     }
 105
 106     /* Copy source buffer to target buffer */
 107
 108     if (Length <= TargetDesc->Buffer.Length)
 109     {
 110         /* Clear existing buffer and copy in the new one */
 111
 112         memset (TargetDesc->Buffer.Pointer, 0, TargetDesc->Buffer.Length);
 113         memcpy (TargetDesc->Buffer.Pointer, Buffer, Length);
 114
 115 #ifdef ACPI_OBSOLETE_BEHAVIOR
 116         /*
 117          * NOTE: ACPI versions up to 3.0 specified that the buffer must be
 118          * truncated if the string is smaller than the buffer. However, "other"
 119          * implementations of ACPI never did this and thus became the defacto
 120          * standard. ACPI 3.0A changes this behavior such that the buffer
 121          * is no longer truncated.
 122          */
 123
 124         /*
 125          * OBSOLETE BEHAVIOR:
 126          * If the original source was a string, we must truncate the buffer,
 127          * according to the ACPI spec. Integer-to-Buffer and Buffer-to-Buffer
 128          * copy must not truncate the original buffer.
 129          */
 130         if (OriginalSrcType == ACPI_TYPE_STRING)
 131         {
 132             /* Set the new length of the target */
 133
 134             TargetDesc->Buffer.Length = Length;
 135         }
 136 #endif
 137     }
 138     else
 139     {
 140         /* Truncate the source, copy only what will fit */
 141
 142         memcpy (TargetDesc->Buffer.Pointer, Buffer,
 143             TargetDesc->Buffer.Length);
 144
 145         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 146             "Truncating source buffer from %X to %X\n",
 147             Length, TargetDesc->Buffer.Length));
 148     }
 149
 150     /* Copy flags */
 151
 152     TargetDesc->Buffer.Flags = SourceDesc->Buffer.Flags;
 153     TargetDesc->Common.Flags &= ~AOPOBJ_STATIC_POINTER;
 154     return_ACPI_STATUS (AE_OK);
 155 }
 156
 157
 158 /*******************************************************************************
 159  *
 160  * FUNCTION:    AcpiExStoreStringToString
 161  *
 162  * PARAMETERS:  SourceDesc          - Source object to copy
 163  *              TargetDesc          - Destination object of the copy
 164  *
 165  * RETURN:      Status
 166  *
 167  * DESCRIPTION: Copy a String object to another String object
 168  *
 169  ******************************************************************************/
 170
 171 ACPI_STATUS
 172 AcpiExStoreStringToString (
 173     ACPI_OPERAND_OBJECT     *SourceDesc,
 174     ACPI_OPERAND_OBJECT     *TargetDesc)
 175 {
 176     UINT32                  Length;
 177     UINT8                   *Buffer;
 178
 179
 180     ACPI_FUNCTION_TRACE_PTR (ExStoreStringToString, SourceDesc);
 181
 182
 183     /* If Source and Target are the same, just return */
 184
 185     if (SourceDesc == TargetDesc)
 186     {
 187         return_ACPI_STATUS (AE_OK);
 188     }
 189
 190     /* We know that SourceDesc is a string by now */
 191
 192     Buffer = ACPI_CAST_PTR (UINT8, SourceDesc->String.Pointer);
 193     Length = SourceDesc->String.Length;
 194
 195     /*
 196      * Replace existing string value if it will fit and the string
 197      * pointer is not a static pointer (part of an ACPI table)
 198      */
 199     if ((Length < TargetDesc->String.Length) &&
 200        (!(TargetDesc->Common.Flags & AOPOBJ_STATIC_POINTER)))
 201     {
 202         /*
 203          * String will fit in existing non-static buffer.
 204          * Clear old string and copy in the new one
 205          */
 206         memset (TargetDesc->String.Pointer, 0,
 207             (ACPI_SIZE) TargetDesc->String.Length + 1);
 208         memcpy (TargetDesc->String.Pointer, Buffer, Length);
 209     }
 210     else
 211     {
 212         /*
 213          * Free the current buffer, then allocate a new buffer
 214          * large enough to hold the value
 215          */
 216         if (TargetDesc->String.Pointer &&
 217            (!(TargetDesc->Common.Flags & AOPOBJ_STATIC_POINTER)))
 218         {
 219             /* Only free if not a pointer into the DSDT */
 220
 221             ACPI_FREE (TargetDesc->String.Pointer);
 222         }
 223
 224         TargetDesc->String.Pointer =
 225             ACPI_ALLOCATE_ZEROED ((ACPI_SIZE) Length + 1);
 226
 227         if (!TargetDesc->String.Pointer)
 228         {
 229             return_ACPI_STATUS (AE_NO_MEMORY);
 230         }
 231
 232         TargetDesc->Common.Flags &= ~AOPOBJ_STATIC_POINTER;
 233         memcpy (TargetDesc->String.Pointer, Buffer, Length);
 234     }
 235
 236     /* Set the new target length */
 237
 238     TargetDesc->String.Length = Length;
 239     return_ACPI_STATUS (AE_OK);
 240 }