tools/power/acpi/common/cmfsize.c

   1 /******************************************************************************
   2  *
   3  * Module Name: cfsize - Common get file size function
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2014, 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/acpi.h>
  45 #include "accommon.h"
  46 #include "acapps.h"
  47 #include <stdio.h>
  48
  49 #define _COMPONENT          ACPI_TOOLS
  50 ACPI_MODULE_NAME("cmfsize")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    cm_get_file_size
  55  *
  56  * PARAMETERS:  file                    - Open file descriptor
  57  *
  58  * RETURN:      File Size. On error, -1 (ACPI_UINT32_MAX)
  59  *
  60  * DESCRIPTION: Get the size of a file. Uses seek-to-EOF. File must be open.
  61  *              Does not disturb the current file pointer.
  62  *
  63  ******************************************************************************/
  64 u32 cm_get_file_size(ACPI_FILE file)
  65 {
  66         long file_size;
  67         long current_offset;
  68         acpi_status status;
  69
  70         /* Save the current file pointer, seek to EOF to obtain file size */
  71
  72         current_offset = acpi_os_get_file_offset(file);
  73         if (current_offset < 0) {
  74                 goto offset_error;
  75         }
  76
  77         status = acpi_os_set_file_offset(file, 0, ACPI_FILE_END);
  78         if (ACPI_FAILURE(status)) {
  79                 goto seek_error;
  80         }
  81
  82         file_size = acpi_os_get_file_offset(file);
  83         if (file_size < 0) {
  84                 goto offset_error;
  85         }
  86
  87         /* Restore original file pointer */
  88
  89         status = acpi_os_set_file_offset(file, current_offset, ACPI_FILE_BEGIN);
  90         if (ACPI_FAILURE(status)) {
  91                 goto seek_error;
  92         }
  93
  94         return ((u32)file_size);
  95
  96 offset_error:
  97         acpi_log_error("Could not get file offset");
  98         return (ACPI_UINT32_MAX);
  99
 100 seek_error:
 101         acpi_log_error("Could not set file offset");
 102         return (ACPI_UINT32_MAX);
 103 }