linux/arch/ia64/sn/kernel/sn2/timer.c
Andy Lutomirski 574c44fa8f ia64: Replace clocksource.fsys_mmio with generic arch data
Now that clocksource.archdata is available, use it for ia64-specific
code.

Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: linux-ia64@vger.kernel.org
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/d31de0ee0842a0e322fb6441571c2b0adb323fa2.1310563276.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-14 17:57:09 -07:00

62 lines
1.5 KiB
C

/*
* linux/arch/ia64/sn/kernel/sn2/timer.c
*
* Copyright (C) 2003 Silicon Graphics, Inc.
* Copyright (C) 2003 Hewlett-Packard Co
* David Mosberger <davidm@hpl.hp.com>: updated for new timer-interpolation infrastructure
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/clocksource.h>
#include <asm/hw_irq.h>
#include <asm/system.h>
#include <asm/timex.h>
#include <asm/sn/leds.h>
#include <asm/sn/shub_mmr.h>
#include <asm/sn/clksupport.h>
extern unsigned long sn_rtc_cycles_per_second;
static cycle_t read_sn2(struct clocksource *cs)
{
return (cycle_t)readq(RTC_COUNTER_ADDR);
}
static struct clocksource clocksource_sn2 = {
.name = "sn2_rtc",
.rating = 450,
.read = read_sn2,
.mask = (1LL << 55) - 1,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
/*
* sn udelay uses the RTC instead of the ITC because the ITC is not
* synchronized across all CPUs, and the thread may migrate to another CPU
* if preemption is enabled.
*/
static void
ia64_sn_udelay (unsigned long usecs)
{
unsigned long start = rtc_time();
unsigned long end = start +
usecs * sn_rtc_cycles_per_second / 1000000;
while (time_before((unsigned long)rtc_time(), end))
cpu_relax();
}
void __init sn_timer_init(void)
{
clocksource_sn2.archdata.fsys_mmio = RTC_COUNTER_ADDR;
clocksource_register_hz(&clocksource_sn2, sn_rtc_cycles_per_second);
ia64_udelay = &ia64_sn_udelay;
}