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

152 lines
4.8 KiB
C

/******************************************************************************
*
* Module Name: osunixmap - Unix OSL for file mappings
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2014, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#include "acpidump.h"
#include <unistd.h>
#include <sys/mman.h>
#ifdef _free_BSD
#include <sys/param.h>
#endif
#define _COMPONENT ACPI_OS_SERVICES
ACPI_MODULE_NAME("osunixmap")
#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifdef _free_BSD
#define MMAP_FLAGS MAP_SHARED
#else
#define MMAP_FLAGS MAP_PRIVATE
#endif
#define SYSTEM_MEMORY "/dev/mem"
/*******************************************************************************
*
* FUNCTION: acpi_os_get_page_size
*
* PARAMETERS: None
*
* RETURN: Page size of the platform.
*
* DESCRIPTION: Obtain page size of the platform.
*
******************************************************************************/
static acpi_size acpi_os_get_page_size(void)
{
#ifdef PAGE_SIZE
return PAGE_SIZE;
#else
return sysconf(_SC_PAGESIZE);
#endif
}
/******************************************************************************
*
* FUNCTION: acpi_os_map_memory
*
* PARAMETERS: where - Physical address of memory to be mapped
* length - How much memory to map
*
* RETURN: Pointer to mapped memory. Null on error.
*
* DESCRIPTION: Map physical memory into local address space.
*
*****************************************************************************/
void *acpi_os_map_memory(acpi_physical_address where, acpi_size length)
{
u8 *mapped_memory;
acpi_physical_address offset;
acpi_size page_size;
int fd;
fd = open(SYSTEM_MEMORY, O_RDONLY | O_BINARY);
if (fd < 0) {
fprintf(stderr, "Cannot open %s\n", SYSTEM_MEMORY);
return (NULL);
}
/* Align the offset to use mmap */
page_size = acpi_os_get_page_size();
offset = where % page_size;
/* Map the table header to get the length of the full table */
mapped_memory = mmap(NULL, (length + offset), PROT_READ, MMAP_FLAGS,
fd, (where - offset));
if (mapped_memory == MAP_FAILED) {
fprintf(stderr, "Cannot map %s\n", SYSTEM_MEMORY);
close(fd);
return (NULL);
}
close(fd);
return (ACPI_CAST8(mapped_memory + offset));
}
/******************************************************************************
*
* FUNCTION: acpi_os_unmap_memory
*
* PARAMETERS: where - Logical address of memory to be unmapped
* length - How much memory to unmap
*
* RETURN: None.
*
* DESCRIPTION: Delete a previously created mapping. Where and Length must
* correspond to a previous mapping exactly.
*
*****************************************************************************/
void acpi_os_unmap_memory(void *where, acpi_size length)
{
acpi_physical_address offset;
acpi_size page_size;
page_size = acpi_os_get_page_size();
offset = (acpi_physical_address) where % page_size;
munmap((u8 *)where - offset, (length + offset));
}