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2456e85535
ktime is a union because the initial implementation stored the time in scalar nanoseconds on 64 bit machine and in a endianess optimized timespec variant for 32bit machines. The Y2038 cleanup removed the timespec variant and switched everything to scalar nanoseconds. The union remained, but become completely pointless. Get rid of the union and just keep ktime_t as simple typedef of type s64. The conversion was done with coccinelle and some manual mopping up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
133 lines
3.2 KiB
C
133 lines
3.2 KiB
C
/*
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* linux/kernel/time/tick-oneshot.c
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*
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* This file contains functions which manage high resolution tick
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* related events.
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*
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* Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
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* Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
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* Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
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*
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* This code is licenced under the GPL version 2. For details see
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* kernel-base/COPYING.
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*/
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#include <linux/cpu.h>
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#include <linux/err.h>
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#include <linux/hrtimer.h>
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#include <linux/interrupt.h>
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#include <linux/percpu.h>
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#include <linux/profile.h>
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#include <linux/sched.h>
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#include "tick-internal.h"
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/**
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* tick_program_event
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*/
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int tick_program_event(ktime_t expires, int force)
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{
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struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
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if (unlikely(expires == KTIME_MAX)) {
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/*
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* We don't need the clock event device any more, stop it.
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*/
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clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT_STOPPED);
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return 0;
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}
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if (unlikely(clockevent_state_oneshot_stopped(dev))) {
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/*
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* We need the clock event again, configure it in ONESHOT mode
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* before using it.
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*/
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clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
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}
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return clockevents_program_event(dev, expires, force);
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}
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/**
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* tick_resume_onshot - resume oneshot mode
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*/
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void tick_resume_oneshot(void)
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{
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struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
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clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
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clockevents_program_event(dev, ktime_get(), true);
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}
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/**
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* tick_setup_oneshot - setup the event device for oneshot mode (hres or nohz)
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*/
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void tick_setup_oneshot(struct clock_event_device *newdev,
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void (*handler)(struct clock_event_device *),
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ktime_t next_event)
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{
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newdev->event_handler = handler;
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clockevents_switch_state(newdev, CLOCK_EVT_STATE_ONESHOT);
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clockevents_program_event(newdev, next_event, true);
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}
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/**
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* tick_switch_to_oneshot - switch to oneshot mode
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*/
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int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
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{
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struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
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struct clock_event_device *dev = td->evtdev;
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if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
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!tick_device_is_functional(dev)) {
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printk(KERN_INFO "Clockevents: "
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"could not switch to one-shot mode:");
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if (!dev) {
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printk(" no tick device\n");
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} else {
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if (!tick_device_is_functional(dev))
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printk(" %s is not functional.\n", dev->name);
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else
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printk(" %s does not support one-shot mode.\n",
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dev->name);
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}
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return -EINVAL;
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}
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td->mode = TICKDEV_MODE_ONESHOT;
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dev->event_handler = handler;
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clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
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tick_broadcast_switch_to_oneshot();
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return 0;
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}
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/**
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* tick_check_oneshot_mode - check whether the system is in oneshot mode
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*
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* returns 1 when either nohz or highres are enabled. otherwise 0.
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*/
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int tick_oneshot_mode_active(void)
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{
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unsigned long flags;
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int ret;
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local_irq_save(flags);
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ret = __this_cpu_read(tick_cpu_device.mode) == TICKDEV_MODE_ONESHOT;
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local_irq_restore(flags);
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return ret;
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}
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#ifdef CONFIG_HIGH_RES_TIMERS
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/**
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* tick_init_highres - switch to high resolution mode
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*
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* Called with interrupts disabled.
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*/
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int tick_init_highres(void)
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{
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return tick_switch_to_oneshot(hrtimer_interrupt);
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}
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#endif
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