linux-sg2042/arch/um/kernel/time.c

137 lines
3.2 KiB
C

/*
* Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2012-2014 Cisco Systems
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
#include <asm/irq.h>
#include <asm/param.h>
#include <kern_util.h>
#include <os.h>
#include <timer-internal.h>
void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
{
unsigned long flags;
local_irq_save(flags);
do_IRQ(TIMER_IRQ, regs);
local_irq_restore(flags);
}
static int itimer_shutdown(struct clock_event_device *evt)
{
os_timer_disable();
return 0;
}
static int itimer_set_periodic(struct clock_event_device *evt)
{
os_timer_set_interval(NULL, NULL);
return 0;
}
static int itimer_next_event(unsigned long delta,
struct clock_event_device *evt)
{
return os_timer_one_shot(delta);
}
static int itimer_one_shot(struct clock_event_device *evt)
{
os_timer_one_shot(1);
return 0;
}
static struct clock_event_device timer_clockevent = {
.name = "posix-timer",
.rating = 250,
.cpumask = cpu_all_mask,
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = itimer_shutdown,
.set_state_periodic = itimer_set_periodic,
.set_state_oneshot = itimer_one_shot,
.set_next_event = itimer_next_event,
.shift = 0,
.max_delta_ns = 0xffffffff,
.max_delta_ticks = 0xffffffff,
.min_delta_ns = TIMER_MIN_DELTA,
.min_delta_ticks = TIMER_MIN_DELTA, // microsecond resolution should be enough for anyone, same as 640K RAM
.irq = 0,
.mult = 1,
};
static irqreturn_t um_timer(int irq, void *dev)
{
if (get_current()->mm != NULL)
{
/* userspace - relay signal, results in correct userspace timers */
os_alarm_process(get_current()->mm->context.id.u.pid);
}
(*timer_clockevent.event_handler)(&timer_clockevent);
return IRQ_HANDLED;
}
static u64 timer_read(struct clocksource *cs)
{
return os_nsecs() / TIMER_MULTIPLIER;
}
static struct clocksource timer_clocksource = {
.name = "timer",
.rating = 300,
.read = timer_read,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static void __init um_timer_setup(void)
{
int err;
err = request_irq(TIMER_IRQ, um_timer, IRQF_TIMER, "hr timer", NULL);
if (err != 0)
printk(KERN_ERR "register_timer : request_irq failed - "
"errno = %d\n", -err);
err = os_timer_create(NULL);
if (err != 0) {
printk(KERN_ERR "creation of timer failed - errno = %d\n", -err);
return;
}
err = clocksource_register_hz(&timer_clocksource, NSEC_PER_SEC/TIMER_MULTIPLIER);
if (err) {
printk(KERN_ERR "clocksource_register_hz returned %d\n", err);
return;
}
clockevents_register_device(&timer_clockevent);
}
void read_persistent_clock(struct timespec *ts)
{
long long nsecs = os_persistent_clock_emulation();
set_normalized_timespec(ts, nsecs / NSEC_PER_SEC,
nsecs % NSEC_PER_SEC);
}
void __init time_init(void)
{
timer_set_signal_handler();
late_time_init = um_timer_setup;
}