freebsd-dev/sys/x86/include/clock.h
Mark Johnston 84369dd523 x86: Probe the TSC frequency earlier
This lets us use the TSC to implement early DELAY, limiting the use of
the sometimes-unreliable 8254 PIT.

PR:		262155
Reviewed by:	emaste
Tested by:	emaste, mike tancsa <mike@sentex.net>, Stefan Hegnauer <stefan.hegnauer@gmx.ch>
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D34367
2022-03-01 09:39:35 -05:00

50 lines
967 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);
void i8254_delay(int);
void clock_init(void);
void lapic_calibrate(void);
void tsc_init(void);
void tsc_calibrate(void);
/*
* Driver to clock driver interface.
*/
void startrtclock(void);
void start_TSC(void);
void resume_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_ */