LXR linux/tools/power/acpi/os_specific/service

   1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2/******************************************************************************
   3 *
   4 * Module Name: osunixmap - Unix OSL for file mappings
   5 *
   6 * Copyright (C) 2000 - 2021, Intel Corp.
   7 *
   8 *****************************************************************************/
   9
  10#include "acpidump.h"
  11#include <unistd.h>
  12#include <sys/mman.h>
  13#ifdef _free_BSD
  14#include <sys/param.h>
  15#endif
  16
  17#define _COMPONENT          ACPI_OS_SERVICES
  18ACPI_MODULE_NAME("osunixmap")
  19
  20#ifndef O_BINARY
  21#define O_BINARY 0
  22#endif
  23#if defined(_dragon_fly) || defined(_free_BSD) || defined(_QNX)
  24#define MMAP_FLAGS          MAP_SHARED
  25#else
  26#define MMAP_FLAGS          MAP_PRIVATE
  27#endif
  28#define SYSTEM_MEMORY       "/dev/mem"
  29/*******************************************************************************
  30 *
  31 * FUNCTION:    acpi_os_get_page_size
  32 *
  33 * PARAMETERS:  None
  34 *
  35 * RETURN:      Page size of the platform.
  36 *
  37 * DESCRIPTION: Obtain page size of the platform.
  38 *
  39 ******************************************************************************/
  40static acpi_size acpi_os_get_page_size(void)
  41{
  42
  43#ifdef PAGE_SIZE
  44        return PAGE_SIZE;
  45#else
  46        return sysconf(_SC_PAGESIZE);
  47#endif
  48}
  49
  50/******************************************************************************
  51 *
  52 * FUNCTION:    acpi_os_map_memory
  53 *
  54 * PARAMETERS:  where               - Physical address of memory to be mapped
  55 *              length              - How much memory to map
  56 *
  57 * RETURN:      Pointer to mapped memory. Null on error.
  58 *
  59 * DESCRIPTION: Map physical memory into local address space.
  60 *
  61 *****************************************************************************/
  62
  63void *acpi_os_map_memory(acpi_physical_address where, acpi_size length)
  64{
  65        u8 *mapped_memory;
  66        acpi_physical_address offset;
  67        acpi_size page_size;
  68        int fd;
  69
  70        fd = open(SYSTEM_MEMORY, O_RDONLY | O_BINARY);
  71        if (fd < 0) {
  72                fprintf(stderr, "Cannot open %s\n", SYSTEM_MEMORY);
  73                return (NULL);
  74        }
  75
  76        /* Align the offset to use mmap */
  77
  78        page_size = acpi_os_get_page_size();
  79        offset = where % page_size;
  80
  81        /* Map the table header to get the length of the full table */
  82
  83        mapped_memory = mmap(NULL, (length + offset), PROT_READ, MMAP_FLAGS,
  84                             fd, (where - offset));
  85        if (mapped_memory == MAP_FAILED) {
  86                fprintf(stderr, "Cannot map %s\n", SYSTEM_MEMORY);
  87                close(fd);
  88                return (NULL);
  89        }
  90
  91        close(fd);
  92        return (ACPI_CAST8(mapped_memory + offset));
  93}
  94
  95/******************************************************************************
  96 *
  97 * FUNCTION:    acpi_os_unmap_memory
  98 *
  99 * PARAMETERS:  where               - Logical address of memory to be unmapped
 100 *              length              - How much memory to unmap
 101 *
 102 * RETURN:      None.
 103 *
 104 * DESCRIPTION: Delete a previously created mapping. Where and Length must
 105 *              correspond to a previous mapping exactly.
 106 *
 107 *****************************************************************************/
 108
 109void acpi_os_unmap_memory(void *where, acpi_size length)
 110{
 111        acpi_physical_address offset;
 112        acpi_size page_size;
 113
 114        page_size = acpi_os_get_page_size();
 115        offset = ACPI_TO_INTEGER(where) % page_size;
 116        munmap((u8 *)where - offset, (length + offset));
 117}
 118