tools/power/acpi/os_specific/service_layers/osunixmap.c

   1 /******************************************************************************
   2  *
   3  * Module Name: osunixmap - Unix OSL for file mappings
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2015, 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 "acpidump.h"
  45 #include <unistd.h>
  46 #include <sys/mman.h>
  47 #ifdef _free_BSD
  48 #include <sys/param.h>
  49 #endif
  50
  51 #define _COMPONENT          ACPI_OS_SERVICES
  52 ACPI_MODULE_NAME("osunixmap")
  53
  54 #ifndef O_BINARY
  55 #define O_BINARY 0
  56 #endif
  57 #ifdef _free_BSD
  58 #define MMAP_FLAGS          MAP_SHARED
  59 #else
  60 #define MMAP_FLAGS          MAP_PRIVATE
  61 #endif
  62 #define SYSTEM_MEMORY       "/dev/mem"
  63 /*******************************************************************************
  64  *
  65  * FUNCTION:    acpi_os_get_page_size
  66  *
  67  * PARAMETERS:  None
  68  *
  69  * RETURN:      Page size of the platform.
  70  *
  71  * DESCRIPTION: Obtain page size of the platform.
  72  *
  73  ******************************************************************************/
  74 static acpi_size acpi_os_get_page_size(void)
  75 {
  76
  77 #ifdef PAGE_SIZE
  78         return PAGE_SIZE;
  79 #else
  80         return sysconf(_SC_PAGESIZE);
  81 #endif
  82 }
  83
  84 /******************************************************************************
  85  *
  86  * FUNCTION:    acpi_os_map_memory
  87  *
  88  * PARAMETERS:  where               - Physical address of memory to be mapped
  89  *              length              - How much memory to map
  90  *
  91  * RETURN:      Pointer to mapped memory. Null on error.
  92  *
  93  * DESCRIPTION: Map physical memory into local address space.
  94  *
  95  *****************************************************************************/
  96
  97 void *acpi_os_map_memory(acpi_physical_address where, acpi_size length)
  98 {
  99         u8 *mapped_memory;
 100         acpi_physical_address offset;
 101         acpi_size page_size;
 102         int fd;
 103
 104         fd = open(SYSTEM_MEMORY, O_RDONLY | O_BINARY);
 105         if (fd < 0) {
 106                 fprintf(stderr, "Cannot open %s\n", SYSTEM_MEMORY);
 107                 return (NULL);
 108         }
 109
 110         /* Align the offset to use mmap */
 111
 112         page_size = acpi_os_get_page_size();
 113         offset = where % page_size;
 114
 115         /* Map the table header to get the length of the full table */
 116
 117         mapped_memory = mmap(NULL, (length + offset), PROT_READ, MMAP_FLAGS,
 118                              fd, (where - offset));
 119         if (mapped_memory == MAP_FAILED) {
 120                 fprintf(stderr, "Cannot map %s\n", SYSTEM_MEMORY);
 121                 close(fd);
 122                 return (NULL);
 123         }
 124
 125         close(fd);
 126         return (ACPI_CAST8(mapped_memory + offset));
 127 }
 128
 129 /******************************************************************************
 130  *
 131  * FUNCTION:    acpi_os_unmap_memory
 132  *
 133  * PARAMETERS:  where               - Logical address of memory to be unmapped
 134  *              length              - How much memory to unmap
 135  *
 136  * RETURN:      None.
 137  *
 138  * DESCRIPTION: Delete a previously created mapping. Where and Length must
 139  *              correspond to a previous mapping exactly.
 140  *
 141  *****************************************************************************/
 142
 143 void acpi_os_unmap_memory(void *where, acpi_size length)
 144 {
 145         acpi_physical_address offset;
 146         acpi_size page_size;
 147
 148         page_size = acpi_os_get_page_size();
 149         offset = (acpi_physical_address) where % page_size;
 150         munmap((u8 *)where - offset, (length + offset));
 151 }