2 * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
3 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
4 * Copyright (C) 2012-2014 Cisco Systems
5 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 * Licensed under the GPL
9 #include <linux/clockchips.h>
10 #include <linux/init.h>
11 #include <linux/interrupt.h>
12 #include <linux/jiffies.h>
14 #include <linux/sched.h>
15 #include <linux/spinlock.h>
16 #include <linux/threads.h>
18 #include <asm/param.h>
19 #include <kern_util.h>
21 #include <timer-internal.h>
23 void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
27 local_irq_save(flags);
28 do_IRQ(TIMER_IRQ, regs);
29 local_irq_restore(flags);
32 static int itimer_shutdown(struct clock_event_device *evt)
38 static int itimer_set_periodic(struct clock_event_device *evt)
40 os_timer_set_interval(NSEC_PER_SEC / HZ);
44 static int itimer_next_event(unsigned long delta,
45 struct clock_event_device *evt)
47 return os_timer_one_shot(delta + 1);
50 static int itimer_one_shot(struct clock_event_device *evt)
56 static struct clock_event_device timer_clockevent = {
57 .name = "posix-timer",
59 .cpumask = cpu_possible_mask,
60 .features = CLOCK_EVT_FEAT_PERIODIC |
61 CLOCK_EVT_FEAT_ONESHOT,
62 .set_state_shutdown = itimer_shutdown,
63 .set_state_periodic = itimer_set_periodic,
64 .set_state_oneshot = itimer_one_shot,
65 .set_next_event = itimer_next_event,
67 .max_delta_ns = 0xffffffff,
68 .max_delta_ticks = 0xffffffff,
69 .min_delta_ns = TIMER_MIN_DELTA,
70 .min_delta_ticks = TIMER_MIN_DELTA, // microsecond resolution should be enough for anyone, same as 640K RAM
75 static irqreturn_t um_timer(int irq, void *dev)
77 if (get_current()->mm != NULL)
79 /* userspace - relay signal, results in correct userspace timers */
80 os_alarm_process(get_current()->mm->context.id.u.pid);
83 (*timer_clockevent.event_handler)(&timer_clockevent);
88 static u64 timer_read(struct clocksource *cs)
90 return os_nsecs() / TIMER_MULTIPLIER;
93 static struct clocksource timer_clocksource = {
97 .mask = CLOCKSOURCE_MASK(64),
98 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
101 static void __init um_timer_setup(void)
105 err = request_irq(TIMER_IRQ, um_timer, IRQF_TIMER, "hr timer", NULL);
107 printk(KERN_ERR "register_timer : request_irq failed - "
108 "errno = %d\n", -err);
110 err = os_timer_create();
112 printk(KERN_ERR "creation of timer failed - errno = %d\n", -err);
116 err = clocksource_register_hz(&timer_clocksource, NSEC_PER_SEC/TIMER_MULTIPLIER);
118 printk(KERN_ERR "clocksource_register_hz returned %d\n", err);
121 clockevents_register_device(&timer_clockevent);
124 void read_persistent_clock64(struct timespec64 *ts)
126 long long nsecs = os_persistent_clock_emulation();
128 set_normalized_timespec64(ts, nsecs / NSEC_PER_SEC,
129 nsecs % NSEC_PER_SEC);
132 void __init time_init(void)
134 timer_set_signal_handler();
135 late_time_init = um_timer_setup;