summaryrefslogtreecommitdiffstats
path: root/arch/um/kernel/time.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/um/kernel/time.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/um/kernel/time.c')
-rw-r--r--arch/um/kernel/time.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
new file mode 100644
index 000000000..0c572a481
--- /dev/null
+++ b/arch/um/kernel/time.c
@@ -0,0 +1,136 @@
+/*
+ * 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_possible_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_clock64(struct timespec64 *ts)
+{
+ long long nsecs = os_persistent_clock_emulation();
+
+ set_normalized_timespec64(ts, nsecs / NSEC_PER_SEC,
+ nsecs % NSEC_PER_SEC);
+}
+
+void __init time_init(void)
+{
+ timer_set_signal_handler();
+ late_time_init = um_timer_setup;
+}