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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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8ab3a284a6
In preparation for making the clockevents core NTP correction aware, all clockevent device drivers must set ->min_delta_ticks and ->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a clockevent device's rate is going to change dynamically and thus, the ratio of ns to ticks ceases to stay invariant. Make the uml arch's clockevent driver initialize these fields properly. This patch alone doesn't introduce any change in functionality as the clockevents core still looks exclusively at the (untouched) ->min_delta_ns and ->max_delta_ns. As soon as this has changed, a followup patch will purge the initialization of ->min_delta_ns and ->max_delta_ns from this driver. Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Jeff Dike <jdike@addtoit.com> Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
136 lines
3.2 KiB
C
136 lines
3.2 KiB
C
/*
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* Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
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* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
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* Copyright (C) 2012-2014 Cisco Systems
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*/
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#include <linux/clockchips.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/jiffies.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/spinlock.h>
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#include <linux/threads.h>
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#include <asm/irq.h>
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#include <asm/param.h>
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#include <kern_util.h>
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#include <os.h>
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#include <timer-internal.h>
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void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
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{
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unsigned long flags;
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local_irq_save(flags);
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do_IRQ(TIMER_IRQ, regs);
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local_irq_restore(flags);
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}
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static int itimer_shutdown(struct clock_event_device *evt)
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{
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os_timer_disable();
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return 0;
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}
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static int itimer_set_periodic(struct clock_event_device *evt)
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{
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os_timer_set_interval(NULL, NULL);
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return 0;
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}
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static int itimer_next_event(unsigned long delta,
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struct clock_event_device *evt)
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{
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return os_timer_one_shot(delta);
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}
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static int itimer_one_shot(struct clock_event_device *evt)
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{
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os_timer_one_shot(1);
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return 0;
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}
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static struct clock_event_device timer_clockevent = {
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.name = "posix-timer",
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.rating = 250,
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.cpumask = cpu_all_mask,
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.features = CLOCK_EVT_FEAT_PERIODIC |
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CLOCK_EVT_FEAT_ONESHOT,
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.set_state_shutdown = itimer_shutdown,
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.set_state_periodic = itimer_set_periodic,
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.set_state_oneshot = itimer_one_shot,
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.set_next_event = itimer_next_event,
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.shift = 0,
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.max_delta_ns = 0xffffffff,
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.max_delta_ticks = 0xffffffff,
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.min_delta_ns = TIMER_MIN_DELTA,
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.min_delta_ticks = TIMER_MIN_DELTA, // microsecond resolution should be enough for anyone, same as 640K RAM
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.irq = 0,
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.mult = 1,
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};
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static irqreturn_t um_timer(int irq, void *dev)
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{
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if (get_current()->mm != NULL)
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{
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/* userspace - relay signal, results in correct userspace timers */
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os_alarm_process(get_current()->mm->context.id.u.pid);
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}
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(*timer_clockevent.event_handler)(&timer_clockevent);
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return IRQ_HANDLED;
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}
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static u64 timer_read(struct clocksource *cs)
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{
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return os_nsecs() / TIMER_MULTIPLIER;
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}
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static struct clocksource timer_clocksource = {
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.name = "timer",
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.rating = 300,
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.read = timer_read,
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.mask = CLOCKSOURCE_MASK(64),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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static void __init timer_setup(void)
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{
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int err;
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err = request_irq(TIMER_IRQ, um_timer, IRQF_TIMER, "hr timer", NULL);
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if (err != 0)
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printk(KERN_ERR "register_timer : request_irq failed - "
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"errno = %d\n", -err);
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err = os_timer_create(NULL);
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if (err != 0) {
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printk(KERN_ERR "creation of timer failed - errno = %d\n", -err);
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return;
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}
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err = clocksource_register_hz(&timer_clocksource, NSEC_PER_SEC/TIMER_MULTIPLIER);
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if (err) {
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printk(KERN_ERR "clocksource_register_hz returned %d\n", err);
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return;
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}
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clockevents_register_device(&timer_clockevent);
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}
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void read_persistent_clock(struct timespec *ts)
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{
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long long nsecs = os_persistent_clock_emulation();
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set_normalized_timespec(ts, nsecs / NSEC_PER_SEC,
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nsecs % NSEC_PER_SEC);
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}
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void __init time_init(void)
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{
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timer_set_signal_handler();
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late_time_init = timer_setup;
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}
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