4b786e24ca
Instead of tracking all the various timer configurations, modify the time-travel mode to have an event scheduler and use a timer event on the scheduler to handle the different timer configurations. This doesn't change the function right now, but it prepares the code for having different kinds of events in the future (i.e. interrupts coming from other devices that are part of co-simulation.) While at it, also move time_travel_sleep() to time.c to reduce the externally visible API surface. Also, we really should mark time-travel as incompatible with SMP, even if UML doesn't support SMP yet. Finally, I noticed a bug while developing this - if we move time forward due to consuming time while reading the clock, we might move across the next event and that would cause us to go backward in time when we then handle that event. Fix that by invoking the whole event machine in this case, but in order to simplify this, make reading the clock only cost something when interrupts are not disabled. Otherwise, we'd have to hook into the interrupt delivery machinery etc. and that's somewhat intrusive. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Copyright (C) 2012 - 2014 Cisco Systems
|
|
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
|
|
*/
|
|
|
|
#ifndef __TIMER_INTERNAL_H__
|
|
#define __TIMER_INTERNAL_H__
|
|
#include <linux/list.h>
|
|
|
|
#define TIMER_MULTIPLIER 256
|
|
#define TIMER_MIN_DELTA 500
|
|
|
|
enum time_travel_mode {
|
|
TT_MODE_OFF,
|
|
TT_MODE_BASIC,
|
|
TT_MODE_INFCPU,
|
|
};
|
|
|
|
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
|
|
struct time_travel_event {
|
|
unsigned long long time;
|
|
void (*fn)(struct time_travel_event *d);
|
|
struct list_head list;
|
|
bool pending, onstack;
|
|
};
|
|
|
|
extern enum time_travel_mode time_travel_mode;
|
|
|
|
void time_travel_sleep(unsigned long long duration);
|
|
|
|
static inline void
|
|
time_travel_set_event_fn(struct time_travel_event *e,
|
|
void (*fn)(struct time_travel_event *d))
|
|
{
|
|
e->fn = fn;
|
|
}
|
|
#else
|
|
struct time_travel_event {
|
|
};
|
|
|
|
#define time_travel_mode TT_MODE_OFF
|
|
|
|
static inline void time_travel_sleep(unsigned long long duration)
|
|
{
|
|
}
|
|
|
|
/* this is a macro so the event/function need not exist */
|
|
#define time_travel_set_event_fn(e, fn) do {} while (0)
|
|
#endif /* CONFIG_UML_TIME_TRAVEL_SUPPORT */
|
|
#endif /* __TIMER_INTERNAL_H__ */
|