freebsd-skq/sys/amd64/include/clock.h
Neel Natu 1472b87f2f Unsynchronized TSCs on the host require special handling in bhyve:
- use clock_gettime(2) as the time base for the emulated ACPI timer instead
  of directly using rdtsc().

- don't advertise the invariant TSC capability to the guest to discourage it
  from using the TSC as its time base.

Discussed with:	jhb@ (about making 'smp_tsc' a global)
Reported by:	Dan Mack on freebsd-virtualization@
Obtained from:	NetApp
2013-04-10 05:59:07 +00:00

44 lines
822 B
C

/*-
* Kernel interface to machine-dependent clock driver.
* Garrett Wollman, September 1994.
* This file is in the public domain.
*
* $FreeBSD$
*/
#ifndef _MACHINE_CLOCK_H_
#define _MACHINE_CLOCK_H_
#ifdef _KERNEL
/*
* i386 to clock driver interface.
* XXX large parts of the driver and its interface are misplaced.
*/
extern int clkintr_pending;
extern u_int i8254_freq;
extern int i8254_max_count;
extern uint64_t tsc_freq;
extern int tsc_is_invariant;
extern int tsc_perf_stat;
#ifdef SMP
extern int smp_tsc;
#endif
void i8254_init(void);
/*
* Driver to clock driver interface.
*/
void startrtclock(void);
void init_TSC(void);
#define HAS_TIMER_SPKR 1
int timer_spkr_acquire(void);
int timer_spkr_release(void);
void timer_spkr_setfreq(int freq);
#endif /* _KERNEL */
#endif /* !_MACHINE_CLOCK_H_ */