Commit 9c82de55 authored by Tiwei Bie's avatar Tiwei Bie Committed by Johannes Berg
Browse files

um: Define timers on a per-CPU basis 



Define timers on a per-CPU basis to enable each CPU to have its
own timer. This is a preparation for adding SMP support.

Signed-off-by: default avatarTiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20251027001815.1666872-5-tiwei.bie@linux.dev


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 2670917c

arch/um/include/linux/time-internal.h

+3 −0
Original line number Diff line number Diff line
@@ -90,4 +90,7 @@ extern unsigned long tt_extra_sched_jiffies; 
 * which is intentional since we really shouldn't link it in that case.

 */

void time_travel_ndelay(unsigned long nsec);



int um_setup_timer(void);



#endif /* __TIMER_INTERNAL_H__ */

arch/um/include/shared/os.h

+3 −3
Original line number Diff line number Diff line
@@ -269,9 +269,9 @@ extern void os_warn(const char *fmt, ...) 
/* time.c */

extern void os_idle_sleep(void);

extern int os_timer_create(void);

extern int os_timer_set_interval(unsigned long long nsecs);

extern int os_timer_one_shot(unsigned long long nsecs);

extern void os_timer_disable(void);

extern int os_timer_set_interval(int cpu, unsigned long long nsecs);

extern int os_timer_one_shot(int cpu, unsigned long long nsecs);

extern void os_timer_disable(int cpu);

extern long long os_persistent_clock_emulation(void);

extern long long os_nsecs(void);

arch/um/kernel/irq.c

+1 −1
Original line number Diff line number Diff line
@@ -683,7 +683,7 @@ void __init init_IRQ(void) 
{

	int i;



	irq_set_chip_and_handler(TIMER_IRQ, &alarm_irq_type, handle_edge_irq);

	irq_set_chip_and_handler(TIMER_IRQ, &alarm_irq_type, handle_percpu_irq);



	for (i = 1; i < UM_LAST_SIGNAL_IRQ; i++)

		irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq);

arch/um/kernel/time.c

+41 −17
Original line number Diff line number Diff line
@@ -625,9 +625,10 @@ void time_travel_sleep(void) 
	 * controller application.

	 */

	unsigned long long next = S64_MAX;

	int cpu = raw_smp_processor_id();



	if (time_travel_mode == TT_MODE_BASIC)

		os_timer_disable();

		os_timer_disable(cpu);



	time_travel_update_time(next, true);
@@ -638,9 +639,9 @@ void time_travel_sleep(void) 
			 * This is somewhat wrong - we should get the first

			 * one sooner like the os_timer_one_shot() below...

			 */

			os_timer_set_interval(time_travel_timer_interval);

			os_timer_set_interval(cpu, time_travel_timer_interval);

		} else {

			os_timer_one_shot(time_travel_timer_event.time - next);

			os_timer_one_shot(cpu, time_travel_timer_event.time - next);

		}

	}

}
@@ -758,6 +759,8 @@ extern u64 time_travel_ext_req(u32 op, u64 time); 
#define time_travel_del_event(e) do { } while (0)

#endif



static struct clock_event_device timer_clockevent[NR_CPUS];



void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)

{

	unsigned long flags;
@@ -780,12 +783,14 @@ void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) 


static int itimer_shutdown(struct clock_event_device *evt)

{

	int cpu = evt - &timer_clockevent[0];



	if (time_travel_mode != TT_MODE_OFF)

		time_travel_del_event(&time_travel_timer_event);



	if (time_travel_mode != TT_MODE_INFCPU &&

	    time_travel_mode != TT_MODE_EXTERNAL)

		os_timer_disable();

		os_timer_disable(cpu);



	return 0;

}
@@ -793,6 +798,7 @@ static int itimer_shutdown(struct clock_event_device *evt) 
static int itimer_set_periodic(struct clock_event_device *evt)

{

	unsigned long long interval = NSEC_PER_SEC / HZ;

	int cpu = evt - &timer_clockevent[0];



	if (time_travel_mode != TT_MODE_OFF) {

		time_travel_del_event(&time_travel_timer_event);
@@ -805,7 +811,7 @@ static int itimer_set_periodic(struct clock_event_device *evt) 


	if (time_travel_mode != TT_MODE_INFCPU &&

	    time_travel_mode != TT_MODE_EXTERNAL)

		os_timer_set_interval(interval);

		os_timer_set_interval(cpu, interval);



	return 0;

}
@@ -825,7 +831,7 @@ static int itimer_next_event(unsigned long delta, 


	if (time_travel_mode != TT_MODE_INFCPU &&

	    time_travel_mode != TT_MODE_EXTERNAL)

		return os_timer_one_shot(delta);

		return os_timer_one_shot(raw_smp_processor_id(), delta);



	return 0;

}
@@ -835,10 +841,9 @@ static int itimer_one_shot(struct clock_event_device *evt) 
	return itimer_next_event(0, evt);

}



static struct clock_event_device timer_clockevent = {

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,
@@ -856,6 +861,9 @@ static struct clock_event_device timer_clockevent = { 


static irqreturn_t um_timer(int irq, void *dev)

{

	int cpu = raw_smp_processor_id();

	struct clock_event_device *evt = &timer_clockevent[cpu];



	/*

	 * Interrupt the (possibly) running userspace process, technically this

	 * should only happen if userspace is currently executing.
@@ -867,7 +875,7 @@ static irqreturn_t um_timer(int irq, void *dev) 
	    get_current()->mm)

		os_alarm_process(get_current()->mm->context.id.pid);



	(*timer_clockevent.event_handler)(&timer_clockevent);

	evt->event_handler(evt);



	return IRQ_HANDLED;

}
@@ -904,7 +912,24 @@ static struct clocksource timer_clocksource = { 
	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,

};



static void __init um_timer_setup(void)

int um_setup_timer(void)

{

	int cpu = raw_smp_processor_id();

	struct clock_event_device *evt = &timer_clockevent[cpu];

	int err;



	err = os_timer_create();

	if (err)

		return err;



	memcpy(evt, &_timer_clockevent, sizeof(*evt));

	evt->cpumask = cpumask_of(cpu);

	clockevents_register_device(evt);



	return 0;

}



static void __init um_timer_init(void)

{

	int err;
@@ -913,8 +938,8 @@ static void __init um_timer_setup(void) 
		printk(KERN_ERR "register_timer : request_irq failed - "

		       "errno = %d\n", -err);



	err = os_timer_create();

	if (err != 0) {

	err = um_setup_timer();

	if (err) {

		printk(KERN_ERR "creation of timer failed - errno = %d\n", -err);

		return;

	}
@@ -924,7 +949,6 @@ static void __init um_timer_setup(void) 
		printk(KERN_ERR "clocksource_register_hz returned %d\n", err);

		return;

	}

	clockevents_register_device(&timer_clockevent);

}



void read_persistent_clock64(struct timespec64 *ts)
@@ -945,7 +969,7 @@ void read_persistent_clock64(struct timespec64 *ts) 
void __init time_init(void)

{

	timer_set_signal_handler();

	late_time_init = um_timer_setup;

	late_time_init = um_timer_init;

}



#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
@@ -961,21 +985,21 @@ static int setup_time_travel(char *str) 
{

	if (strcmp(str, "=inf-cpu") == 0) {

		time_travel_mode = TT_MODE_INFCPU;

		timer_clockevent.name = "time-travel-timer-infcpu";

		_timer_clockevent.name = "time-travel-timer-infcpu";

		timer_clocksource.name = "time-travel-clock";

		return 1;

	}



	if (strncmp(str, "=ext:", 5) == 0) {

		time_travel_mode = TT_MODE_EXTERNAL;

		timer_clockevent.name = "time-travel-timer-external";

		_timer_clockevent.name = "time-travel-timer-external";

		timer_clocksource.name = "time-travel-clock-external";

		return time_travel_connect_external(str + 5);

	}



	if (!*str) {

		time_travel_mode = TT_MODE_BASIC;

		timer_clockevent.name = "time-travel-timer";

		_timer_clockevent.name = "time-travel-timer";

		timer_clocksource.name = "time-travel-clock";

		return 1;

	}

arch/um/os-Linux/main.c

+1 −1
Original line number Diff line number Diff line
@@ -171,7 +171,7 @@ int __init main(int argc, char **argv, char **envp) 
	 */



	/* stop timers and set timer signal to be ignored */

	os_timer_disable();

	os_timer_disable(0);



	/* disable SIGIO for the fds and set SIGIO to be ignored */

	err = deactivate_all_fds();