android_kernel_xiaomi_sm8350/arch/xtensa/kernel/time.c
Atsushi Nemoto 8ef386092d [PATCH] kill wall_jiffies
With 2.6.18-rc4-mm2, now wall_jiffies will always be the same as jiffies.
So we can kill wall_jiffies completely.

This is just a cleanup and logically should not change any real behavior
except for one thing: RTC updating code in (old) ppc and xtensa use a
condition "jiffies - wall_jiffies == 1".  This condition is never met so I
suppose it is just a bug.  I just remove that condition only instead of
kill the whole "if" block.

[heiko.carstens@de.ibm.com: s390 build fix and cleanup]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:27 -07:00

214 lines
4.8 KiB
C

/*
* arch/xtensa/kernel/time.c
*
* Timer and clock support.
*
* 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.
*
* Copyright (C) 2005 Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
*/
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/profile.h>
#include <linux/delay.h>
#include <asm/timex.h>
#include <asm/platform.h>
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
unsigned long ccount_per_jiffy; /* per 1/HZ */
unsigned long ccount_nsec; /* nsec per ccount increment */
#endif
unsigned int last_ccount_stamp;
static long last_rtc_update = 0;
/*
* Scheduler clock - returns current tim in nanosec units.
*/
unsigned long long sched_clock(void)
{
return (unsigned long long)jiffies * (1000000000 / HZ);
}
static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs);
static struct irqaction timer_irqaction = {
.handler = timer_interrupt,
.flags = IRQF_DISABLED,
.name = "timer",
};
void __init time_init(void)
{
time_t sec_o, sec_n = 0;
/* The platform must provide a function to calibrate the processor
* speed for the CALIBRATE.
*/
#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
printk("Calibrating CPU frequency ");
platform_calibrate_ccount();
printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ),
(int)(ccount_per_jiffy/(10000/HZ))%100);
#endif
/* Set time from RTC (if provided) */
if (platform_get_rtc_time(&sec_o) == 0)
while (platform_get_rtc_time(&sec_n))
if (sec_o != sec_n)
break;
xtime.tv_nsec = 0;
last_rtc_update = xtime.tv_sec = sec_n;
last_ccount_stamp = get_ccount();
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
/* Initialize the linux timer interrupt. */
setup_irq(LINUX_TIMER_INT, &timer_irqaction);
set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY);
}
int do_settimeofday(struct timespec *tv)
{
time_t wtm_sec, sec = tv->tv_sec;
long wtm_nsec, nsec = tv->tv_nsec;
unsigned long ccount;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irq(&xtime_lock);
/* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
* wall time. Discover what correction gettimeofday() would have
* made, and then undo it!
*/
ccount = get_ccount();
nsec -= (ccount - last_ccount_stamp) * CCOUNT_NSEC;
wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
set_normalized_timespec(&xtime, sec, nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
ntp_clear();
write_sequnlock_irq(&xtime_lock);
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long sec, usec, delta, seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
delta = get_ccount() - last_ccount_stamp;
sec = xtime.tv_sec;
usec = (xtime.tv_nsec / NSEC_PER_USEC);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
usec += (delta * CCOUNT_NSEC) / NSEC_PER_USEC;
for (; usec >= 1000000; sec++, usec -= 1000000)
;
tv->tv_sec = sec;
tv->tv_usec = usec;
}
EXPORT_SYMBOL(do_gettimeofday);
/*
* The timer interrupt is called HZ times per second.
*/
irqreturn_t timer_interrupt (int irq, void *dev_id, struct pt_regs *regs)
{
unsigned long next;
next = get_linux_timer();
again:
while ((signed long)(get_ccount() - next) > 0) {
profile_tick(CPU_PROFILING, regs);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
write_seqlock(&xtime_lock);
last_ccount_stamp = next;
next += CCOUNT_PER_JIFFY;
do_timer (1); /* Linux handler in kernel/timer.c */
if (ntp_synced() &&
xtime.tv_sec - last_rtc_update >= 659 &&
abs((xtime.tv_nsec/1000)-(1000000-1000000/HZ))<5000000/HZ) {
if (platform_set_rtc_time(xtime.tv_sec+1) == 0)
last_rtc_update = xtime.tv_sec+1;
else
/* Do it again in 60 s */
last_rtc_update += 60;
}
write_sequnlock(&xtime_lock);
}
/* NOTE: writing CCOMPAREn clears the interrupt. */
set_linux_timer (next);
/* Make sure we didn't miss any tick... */
if ((signed long)(get_ccount() - next) > 0)
goto again;
/* Allow platform to do something useful (Wdog). */
platform_heartbeat();
return IRQ_HANDLED;
}
#ifndef CONFIG_GENERIC_CALIBRATE_DELAY
void __devinit calibrate_delay(void)
{
loops_per_jiffy = CCOUNT_PER_JIFFY;
printk("Calibrating delay loop (skipped)... "
"%lu.%02lu BogoMIPS preset\n",
loops_per_jiffy/(1000000/HZ),
(loops_per_jiffy/(10000/HZ)) % 100);
}
#endif