kernel_optimize_test/arch/sh/kernel/time.c
Martin Schwidefsky d4f587c67f timekeeping: Increase granularity of read_persistent_clock()
The persistent clock of some architectures (e.g. s390) have a
better granularity than seconds. To reduce the delta between the
host clock and the guest clock in a virtualized system change the 
read_persistent_clock function to return a struct timespec.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
LKML-Reference: <20090814134811.013873340@de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-15 10:55:46 +02:00

119 lines
2.7 KiB
C

/*
* arch/sh/kernel/time.c
*
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 2002 - 2009 Paul Mundt
* Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/profile.h>
#include <linux/timex.h>
#include <linux/sched.h>
#include <linux/clockchips.h>
#include <linux/platform_device.h>
#include <linux/smp.h>
#include <linux/rtc.h>
#include <asm/clock.h>
#include <asm/rtc.h>
/* Dummy RTC ops */
static void null_rtc_get_time(struct timespec *tv)
{
tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
tv->tv_nsec = 0;
}
static int null_rtc_set_time(const time_t secs)
{
return 0;
}
void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time;
int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
#ifdef CONFIG_GENERIC_CMOS_UPDATE
void read_persistent_clock(struct timespec *ts)
{
rtc_sh_get_time(&ts);
}
int update_persistent_clock(struct timespec now)
{
return rtc_sh_set_time(now.tv_sec);
}
#endif
unsigned int get_rtc_time(struct rtc_time *tm)
{
if (rtc_sh_get_time != null_rtc_get_time) {
struct timespec tv;
rtc_sh_get_time(&tv);
rtc_time_to_tm(tv.tv_sec, tm);
}
return RTC_24H;
}
EXPORT_SYMBOL(get_rtc_time);
int set_rtc_time(struct rtc_time *tm)
{
unsigned long secs;
rtc_tm_to_time(tm, &secs);
return rtc_sh_set_time(secs);
}
EXPORT_SYMBOL(set_rtc_time);
static int __init rtc_generic_init(void)
{
struct platform_device *pdev;
if (rtc_sh_get_time == null_rtc_get_time)
return -ENODEV;
pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
return 0;
}
module_init(rtc_generic_init);
void (*board_time_init)(void);
void __init time_init(void)
{
if (board_time_init)
board_time_init();
clk_init();
rtc_sh_get_time(&xtime);
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
local_timer_setup(smp_processor_id());
#endif
/*
* Make sure all compiled-in early timers register themselves.
*
* Run probe() for two "earlytimer" devices, these will be the
* clockevents and clocksource devices respectively. In the event
* that only a clockevents device is available, we -ENODEV on the
* clocksource and the jiffies clocksource is used transparently
* instead. No error handling is necessary here.
*/
early_platform_driver_register_all("earlytimer");
early_platform_driver_probe("earlytimer", 2, 0);
}