freebsd-dev/sys/amd64/include/clock.h
Andriy Gapon 279be68bfd re-synchronize TSC-s on SMP systems after resume, if necessary
The TSC-s are checked and synchronized only if they were good
originally.  That is, invariant, synchronized, etc.

This is necessary on an AMD-based system where after a wakeup from STR I
see that BSP clock differs from AP clocks by a count that roughly
corresponds to one second.  The APs are in sync with each other.  Not
sure if this is a hardware quirk or a firmware bug.

This is what I see after a resume with this change:
    SMP: passed TSC synchronization test after adjustment
    acpi_timer0: restoring timecounter, ACPI-fast -> TSC-low

Reviewed by:	kib
MFC after:	3 weeks
Differential Revision: https://reviews.freebsd.org/D15551
2018-05-25 07:33:20 +00:00

47 lines
891 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);
/*
* Driver to clock driver interface.
*/
void startrtclock(void);
void init_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_ */