1 // SPDX-License-Identifier: GPL-2.0
3  * This file contains functions which emulate a local clock-event
4  * device via a broadcast event source.
6  * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
7  * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
8  * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
20 #include "tick-internal.h"
79 	if ((newdev->features & CLOCK_EVT_FEAT_DUMMY) ||  in tick_check_broadcast_device()
80 	    (newdev->features & CLOCK_EVT_FEAT_PERCPU) ||  in tick_check_broadcast_device()
81 	    (newdev->features & CLOCK_EVT_FEAT_C3STOP))  in tick_check_broadcast_device()
85 	    !(newdev->features & CLOCK_EVT_FEAT_ONESHOT))  in tick_check_broadcast_device()
88 	return !curdev || newdev->rating > curdev->rating;  in tick_check_broadcast_device()
101 	if (!try_module_get(dev->owner))  in tick_install_broadcast_device()
106 		cur->event_handler = clockevents_handle_noop;  in tick_install_broadcast_device()
118 	if (dev->features & CLOCK_EVT_FEAT_ONESHOT)  in tick_install_broadcast_device()
132 	int ret = -ENODEV;  in tick_broadcast_update_freq()
150 	if (!dev->broadcast)  in tick_device_setup_broadcast_func()
151 		dev->broadcast = tick_broadcast;  in tick_device_setup_broadcast_func()
152 	if (!dev->broadcast) {  in tick_device_setup_broadcast_func()
154 			     dev->name);  in tick_device_setup_broadcast_func()
155 		dev->broadcast = err_broadcast;  in tick_device_setup_broadcast_func()
178 		dev->event_handler = tick_handle_periodic;  in tick_device_uses_broadcast()
191 		if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))  in tick_device_uses_broadcast()
233 			if (bc && !(bc->features & CLOCK_EVT_FEAT_HRTIMER))  in tick_device_uses_broadcast()
248 	struct clock_event_device *evt = td->evtdev;  in tick_receive_broadcast()
251 		return -ENODEV;  in tick_receive_broadcast()
253 	if (!evt->event_handler)  in tick_receive_broadcast()
254 		return -EINVAL;  in tick_receive_broadcast()
256 	evt->event_handler(evt);  in tick_receive_broadcast()
262  * Broadcast the event to the cpus, which are set in the mask (mangled).
289 		local = !(bc->features & CLOCK_EVT_FEAT_HRTIMER);  in tick_do_broadcast()
300 		td->evtdev->broadcast(mask);  in tick_do_broadcast()
307  * - invoke the broadcast handlers
316  * Event handler for periodic broadcast ticks
334 		ktime_t next = ktime_add(dev->next_event, tick_period);  in tick_handle_periodic_broadcast()
346 		td->evtdev->event_handler(td->evtdev);  in tick_handle_periodic_broadcast()
350  * tick_broadcast_control - Enable/disable or force broadcast mode
366 	dev = td->evtdev;  in tick_broadcast_control()
371 	if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP))  in tick_broadcast_control()
391 			 * - the broadcast device exists  in tick_broadcast_control()
392 			 * - the broadcast device is not a hrtimer based one  in tick_broadcast_control()
393 			 * - the broadcast device is in periodic mode to  in tick_broadcast_control()
396 			if (bc && !(bc->features & CLOCK_EVT_FEAT_HRTIMER) &&  in tick_broadcast_control()
436 		dev->event_handler = tick_handle_periodic;  in tick_set_periodic_handler()
438 		dev->event_handler = tick_handle_periodic_broadcast;  in tick_set_periodic_handler()
539  * broadcast event from the other core is about to happen. We detected
541  * to avoid a deep idle transition as we are about to get the
555 	if (!(bc->features & CLOCK_EVT_FEAT_DYNIRQ))  in tick_broadcast_set_affinity()
558 	if (cpumask_equal(bc->cpumask, cpumask))  in tick_broadcast_set_affinity()
561 	bc->cpumask = cpumask;  in tick_broadcast_set_affinity()
562 	irq_set_affinity(bc->irq, bc->cpumask);  in tick_broadcast_set_affinity()
594 		if (td->mode == TICKDEV_MODE_ONESHOT) {  in tick_check_oneshot_broadcast_this_cpu()
595 			clockevents_switch_state(td->evtdev,  in tick_check_oneshot_broadcast_this_cpu()
612 	dev->next_event = KTIME_MAX;  in tick_handle_oneshot_broadcast()
627 		if (td->evtdev->next_event <= now) {  in tick_handle_oneshot_broadcast()
635 		} else if (td->evtdev->next_event < next_event) {  in tick_handle_oneshot_broadcast()
636 			next_event = td->evtdev->next_event;  in tick_handle_oneshot_broadcast()
642 	 * Remove the current cpu from the pending mask. The event is  in tick_handle_oneshot_broadcast()
659 	 * Wakeup the cpus which have an expired event.  in tick_handle_oneshot_broadcast()
666 	 * - The global event did not expire any CPU local  in tick_handle_oneshot_broadcast()
670 	 * - There are pending events on sleeping CPUs which were not  in tick_handle_oneshot_broadcast()
671 	 * in the event mask  in tick_handle_oneshot_broadcast()
680 		td->evtdev->event_handler(td->evtdev);  in tick_handle_oneshot_broadcast()
686 	if (!(bc->features & CLOCK_EVT_FEAT_HRTIMER))  in broadcast_needs_cpu()
688 	if (bc->next_event == KTIME_MAX)  in broadcast_needs_cpu()
690 	return bc->bound_on == cpu ? -EBUSY : 0;  in broadcast_needs_cpu()
698 	 * local device if our own event is the first one to expire or  in broadcast_shutdown_local()
701 	if (bc->features & CLOCK_EVT_FEAT_HRTIMER) {  in broadcast_shutdown_local()
704 		if (dev->next_event < bc->next_event)  in broadcast_shutdown_local()
718 	 * into deep idle.  in __tick_broadcast_oneshot_control()
721 		return -EBUSY;  in __tick_broadcast_oneshot_control()
723 	dev = this_cpu_ptr(&tick_cpu_device)->evtdev;  in __tick_broadcast_oneshot_control()
732 		 * mechanism, it cannot go deep idle and we do not add  in __tick_broadcast_oneshot_control()
747 			if (bc->features & CLOCK_EVT_FEAT_HRTIMER)  in __tick_broadcast_oneshot_control()
748 				ret = -EBUSY;  in __tick_broadcast_oneshot_control()
761 			 * if the cpu local event is earlier than the  in __tick_broadcast_oneshot_control()
762 			 * broadcast event. If the current CPU is in  in __tick_broadcast_oneshot_control()
765 			 * busy, so the CPU does not try to go deep  in __tick_broadcast_oneshot_control()
769 				ret = -EBUSY;  in __tick_broadcast_oneshot_control()
770 			} else if (dev->next_event < bc->next_event) {  in __tick_broadcast_oneshot_control()
771 				tick_broadcast_set_event(bc, cpu, dev->next_event);  in __tick_broadcast_oneshot_control()
794 			 * event anyway via the broadcast IPI  in __tick_broadcast_oneshot_control()
796 			 * with an already expired event.  in __tick_broadcast_oneshot_control()
803 			 * Bail out if there is no next event.  in __tick_broadcast_oneshot_control()
805 			if (dev->next_event == KTIME_MAX)  in __tick_broadcast_oneshot_control()
815 			 * timer with an already expired event.  in __tick_broadcast_oneshot_control()
817 			 * This can lead to a ping-pong when we return  in __tick_broadcast_oneshot_control()
821 			 * reprogramming makes sure that the event  in __tick_broadcast_oneshot_control()
824 			 * enough out that the ping-pong starts.  in __tick_broadcast_oneshot_control()
840 			if (dev->next_event <= now) {  in __tick_broadcast_oneshot_control()
848 			tick_program_event(dev->next_event, 1);  in __tick_broadcast_oneshot_control()
875 		if (td->evtdev)  in tick_broadcast_init_next_event()
876 			td->evtdev->next_event = expires;  in tick_broadcast_init_next_event()
881  * tick_broadcast_setup_oneshot - setup the broadcast device
891 	if (bc->event_handler != tick_handle_oneshot_broadcast) {  in tick_broadcast_setup_oneshot()
894 		bc->event_handler = tick_handle_oneshot_broadcast;  in tick_broadcast_setup_oneshot()
913 			bc->next_event = KTIME_MAX;  in tick_broadcast_setup_oneshot()
955 		clockevents_program_event(bc, bc->next_event, 1);  in hotplug_cpu__broadcast_tick_pull()
990 	return bc ? bc->features & CLOCK_EVT_FEAT_ONESHOT : false;  in tick_broadcast_oneshot_available()
998 	if (!bc || (bc->features & CLOCK_EVT_FEAT_HRTIMER))  in __tick_broadcast_oneshot_control()
999 		return -EBUSY;  in __tick_broadcast_oneshot_control()