acrn-kernel/tools/power/acpi/os_specific/service_layers/osunixmap.c

118 lines
3.1 KiB
C

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: osunixmap - Unix OSL for file mappings
*
* Copyright (C) 2000 - 2021, Intel Corp.
*
*****************************************************************************/
#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
#if defined(_dragon_fly) || defined(_free_BSD) || defined(_QNX)
#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_TO_INTEGER(where) % page_size;
munmap((u8 *)where - offset, (length + offset));
}