kernel_optimize_test/arch/m68k/kernel/time.c
Stephen Warren 7b1f62076b time: convert arch_gettimeoffset to a pointer
Currently, whenever CONFIG_ARCH_USES_GETTIMEOFFSET is enabled, each
arch core provides a single implementation of arch_gettimeoffset(). In
many cases, different sub-architectures, different machines, or
different timer providers exist, and so the arch ends up implementing
arch_gettimeoffset() as a call-through-pointer anyway. Examples are
ARM, Cris, M68K, and it's arguable that the remaining architectures,
M32R and Blackfin, should be doing this anyway.

Modify arch_gettimeoffset so that it itself is a function pointer, which
the arch initializes. This will allow later changes to move the
initialization of this function into individual machine support or timer
drivers. This is particularly useful for code in drivers/clocksource
which should rely on an arch-independant mechanism to register their
implementation of arch_gettimeoffset().

This patch also converts the Cris architecture to set arch_gettimeoffset
directly to the final implementation in time_init(), because Cris already
had separate time_init() functions per sub-architecture. M68K and ARM
are converted to set arch_gettimeoffset to the final implementation in
later patches, because they already have function pointers in place for
this purpose.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2012-12-24 09:36:07 -07:00

113 lines
2.6 KiB
C

/*
* linux/arch/m68k/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
*
* This file contains the m68k-specific time handling details.
* Most of the stuff is located in the machine specific files.
*
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/irq_regs.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/profile.h>
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "xtime_update()" routine every clocktick
*/
static irqreturn_t timer_interrupt(int irq, void *dummy)
{
xtime_update(1);
update_process_times(user_mode(get_irq_regs()));
profile_tick(CPU_PROFILING);
#ifdef CONFIG_HEARTBEAT
/* use power LED as a heartbeat instead -- much more useful
for debugging -- based on the version for PReP by Cort */
/* acts like an actual heart beat -- ie thump-thump-pause... */
if (mach_heartbeat) {
static unsigned cnt = 0, period = 0, dist = 0;
if (cnt == 0 || cnt == dist)
mach_heartbeat( 1 );
else if (cnt == 7 || cnt == dist+7)
mach_heartbeat( 0 );
if (++cnt > period) {
cnt = 0;
/* The hyperbolic function below modifies the heartbeat period
* length in dependency of the current (5min) load. It goes
* through the points f(0)=126, f(1)=86, f(5)=51,
* f(inf)->30. */
period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
dist = period / 4;
}
}
#endif /* CONFIG_HEARTBEAT */
return IRQ_HANDLED;
}
void read_persistent_clock(struct timespec *ts)
{
struct rtc_time time;
ts->tv_sec = 0;
ts->tv_nsec = 0;
if (mach_hwclk) {
mach_hwclk(0, &time);
if ((time.tm_year += 1900) < 1970)
time.tm_year += 100;
ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
time.tm_hour, time.tm_min, time.tm_sec);
}
}
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
static u32 m68k_gettimeoffset(void)
{
return mach_gettimeoffset() * 1000;
}
static int __init rtc_init(void)
{
struct platform_device *pdev;
if (!mach_hwclk)
return -ENODEV;
pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
return PTR_RET(pdev);
}
module_init(rtc_init);
#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
void __init time_init(void)
{
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
arch_gettimeoffset = m68k_gettimeoffset;
#endif
mach_sched_init(timer_interrupt);
}