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linux-next/arch/arm/kernel/time.c
Xunlei Pang cb850717b0 ARM, clocksource/drivers: Provide read_boot_clock64() and read_persistent_clock64() and use them
As part of addressing "y2038 problem" for in-kernel uses, this
patch converts read_boot_clock() to read_boot_clock64() and
read_persistent_clock() to read_persistent_clock64() using
timespec64 by converting clock_access_fn to use timespec64.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Thierry Reding <treding@nvidia.com> (for tegra part)
Cc: Russell King <rmk@dyn-67.arm.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-7-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 08:18:23 +02:00

126 lines
2.8 KiB
C

/*
* linux/arch/arm/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
* Modifications for ARM (C) 1994-2001 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This file contains the ARM-specific time handling details:
* reading the RTC at bootup, etc...
*/
#include <linux/clk-provider.h>
#include <linux/clocksource.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/profile.h>
#include <linux/sched.h>
#include <linux/sched_clock.h>
#include <linux/smp.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/timer.h>
#include <asm/mach/arch.h>
#include <asm/mach/time.h>
#include <asm/stacktrace.h>
#include <asm/thread_info.h>
#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
/* this needs a better home */
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
#endif /* pc-style 'CMOS' RTC support */
/* change this if you have some constant time drift */
#define USECS_PER_JIFFY (1000000/HZ)
#ifdef CONFIG_SMP
unsigned long profile_pc(struct pt_regs *regs)
{
struct stackframe frame;
if (!in_lock_functions(regs->ARM_pc))
return regs->ARM_pc;
arm_get_current_stackframe(regs, &frame);
do {
int ret = unwind_frame(&frame);
if (ret < 0)
return 0;
} while (in_lock_functions(frame.pc));
return frame.pc;
}
EXPORT_SYMBOL(profile_pc);
#endif
#ifndef CONFIG_GENERIC_CLOCKEVENTS
/*
* Kernel system timer support.
*/
void timer_tick(void)
{
profile_tick(CPU_PROFILING);
xtime_update(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
}
#endif
static void dummy_clock_access(struct timespec64 *ts)
{
ts->tv_sec = 0;
ts->tv_nsec = 0;
}
static clock_access_fn __read_persistent_clock = dummy_clock_access;
static clock_access_fn __read_boot_clock = dummy_clock_access;;
void read_persistent_clock64(struct timespec64 *ts)
{
__read_persistent_clock(ts);
}
void read_boot_clock64(struct timespec64 *ts)
{
__read_boot_clock(ts);
}
int __init register_persistent_clock(clock_access_fn read_boot,
clock_access_fn read_persistent)
{
/* Only allow the clockaccess functions to be registered once */
if (__read_persistent_clock == dummy_clock_access &&
__read_boot_clock == dummy_clock_access) {
if (read_boot)
__read_boot_clock = read_boot;
if (read_persistent)
__read_persistent_clock = read_persistent;
return 0;
}
return -EINVAL;
}
void __init time_init(void)
{
if (machine_desc->init_time) {
machine_desc->init_time();
} else {
#ifdef CONFIG_COMMON_CLK
of_clk_init(NULL);
#endif
clocksource_of_init();
}
}