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