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linux-next/arch/arm64/kernel/time.c
Stephen Boyd 65cd4f6c99 arch_timer: Move to generic sched_clock framework
Register with the generic sched_clock framework now that it
supports 64 bits. This fixes two problems with the current
sched_clock support for machines using the architected timers.
First off, we don't subtract the start value from subsequent
sched_clock calls so we can potentially start off with
sched_clock returning gigantic numbers. Second, there is no
support for suspend/resume handling so problems such as discussed
in 6a4dae5 (ARM: 7565/1: sched: stop sched_clock() during
suspend, 2012-10-23) can happen without this patch. Finally, it
allows us to move the sched_clock setup into drivers clocksource
out of the arch ports.

Cc: Christopher Covington <cov@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-10-09 16:54:10 -07:00

77 lines
1.9 KiB
C

/*
* Based on arch/arm/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
* Modifications for ARM (C) 1994-2001 Russell King
* Copyright (C) 2012 ARM Ltd.
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/timex.h>
#include <linux/errno.h>
#include <linux/profile.h>
#include <linux/syscore_ops.h>
#include <linux/timer.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/clocksource.h>
#include <clocksource/arm_arch_timer.h>
#include <asm/thread_info.h>
#include <asm/stacktrace.h>
#ifdef CONFIG_SMP
unsigned long profile_pc(struct pt_regs *regs)
{
struct stackframe frame;
if (!in_lock_functions(regs->pc))
return regs->pc;
frame.fp = regs->regs[29];
frame.sp = regs->sp;
frame.pc = regs->pc;
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
void __init time_init(void)
{
u32 arch_timer_rate;
clocksource_of_init();
arch_timer_rate = arch_timer_get_rate();
if (!arch_timer_rate)
panic("Unable to initialise architected timer.\n");
/* Calibrate the delay loop directly */
lpj_fine = arch_timer_rate / HZ;
}