acpi-fpdt.c revision cf0fbc49e67b55f8d346fc94de28c90113505297
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Kay Sievers
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "acpi-fpdt.h"
#include "alloc-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "time-util.h"
#include "util.h"
struct acpi_table_header {
char signature[4];
uint32_t length;
uint8_t revision;
uint8_t checksum;
char oem_id[6];
char oem_table_id[8];
uint32_t oem_revision;
char asl_compiler_id[4];
uint32_t asl_compiler_revision;
};
enum {
ACPI_FPDT_TYPE_BOOT = 0,
ACPI_FPDT_TYPE_S3PERF = 1,
};
struct acpi_fpdt_header {
uint16_t type;
uint8_t length;
uint8_t revision;
uint8_t reserved[4];
uint64_t ptr;
};
struct acpi_fpdt_boot_header {
char signature[4];
uint32_t length;
};
enum {
ACPI_FPDT_S3PERF_RESUME_REC = 0,
ACPI_FPDT_S3PERF_SUSPEND_REC = 1,
ACPI_FPDT_BOOT_REC = 2,
};
struct acpi_fpdt_boot {
uint16_t type;
uint8_t length;
uint8_t revision;
uint8_t reserved[4];
uint64_t reset_end;
uint64_t load_start;
uint64_t startup_start;
uint64_t exit_services_entry;
uint64_t exit_services_exit;
};
int acpi_get_boot_usec(usec_t *loader_start, usec_t *loader_exit) {
_cleanup_free_ char *buf = NULL;
struct acpi_table_header *tbl;
size_t l = 0;
struct acpi_fpdt_header *rec;
int r;
uint64_t ptr = 0;
_cleanup_close_ int fd = -1;
struct acpi_fpdt_boot_header hbrec;
struct acpi_fpdt_boot brec;
r = read_full_file("/sys/firmware/acpi/tables/FPDT", &buf, &l);
if (r < 0)
return r;
if (l < sizeof(struct acpi_table_header) + sizeof(struct acpi_fpdt_header))
return -EINVAL;
tbl = (struct acpi_table_header *)buf;
if (l != tbl->length)
return -EINVAL;
if (memcmp(tbl->signature, "FPDT", 4) != 0)
return -EINVAL;
/* find Firmware Basic Boot Performance Pointer Record */
for (rec = (struct acpi_fpdt_header *)(buf + sizeof(struct acpi_table_header));
(char *)rec < buf + l;
rec = (struct acpi_fpdt_header *)((char *)rec + rec->length)) {
if (rec->length <= 0)
break;
if (rec->type != ACPI_FPDT_TYPE_BOOT)
continue;
if (rec->length != sizeof(struct acpi_fpdt_header))
continue;
ptr = rec->ptr;
break;
}
if (ptr == 0)
return -EINVAL;
/* read Firmware Basic Boot Performance Data Record */
fd = open("/dev/mem", O_CLOEXEC|O_RDONLY);
if (fd < 0)
return -errno;
l = pread(fd, &hbrec, sizeof(struct acpi_fpdt_boot_header), ptr);
if (l != sizeof(struct acpi_fpdt_boot_header))
return -EINVAL;
if (memcmp(hbrec.signature, "FBPT", 4) != 0)
return -EINVAL;
if (hbrec.length < sizeof(struct acpi_fpdt_boot_header) + sizeof(struct acpi_fpdt_boot))
return -EINVAL;
l = pread(fd, &brec, sizeof(struct acpi_fpdt_boot), ptr + sizeof(struct acpi_fpdt_boot_header));
if (l != sizeof(struct acpi_fpdt_boot))
return -EINVAL;
if (brec.length != sizeof(struct acpi_fpdt_boot))
return -EINVAL;
if (brec.type != ACPI_FPDT_BOOT_REC)
return -EINVAL;
if (brec.startup_start == 0 || brec.exit_services_exit < brec.startup_start)
return -EINVAL;
if (brec.exit_services_exit > NSEC_PER_HOUR)
return -EINVAL;
if (loader_start)
*loader_start = brec.startup_start / 1000;
if (loader_exit)
*loader_exit = brec.exit_services_exit / 1000;
return 0;
}