clock.h revision 12724 
1/*
2 * Kernel interface to machine-dependent clock driver.
3 * Garrett Wollman, September 1994.
4 * This file is in the public domain.
5 *
6 *	$Id: clock.h,v 1.6 1995/11/29 19:57:16 wollman Exp $
7 */
8
9#ifndef _MACHINE_CLOCK_H_
10#define	_MACHINE_CLOCK_H_
11
12#ifdef I586_CPU
13
14#define I586_CYCLECTR(x) \
15	__asm __volatile(".byte 0x0f, 0x31" : "=A" (x))
16
17/*
18 * When we update the clock, we also update this bias value which is
19 * automatically subtracted in microtime().  We assume that CPU_THISTICKLEN()
20 * has been called at some point in the past, so that an appropriate value is
21 * set up in i586_last_tick.  (This works even if we are not being called
22 * from hardclock because hardclock will have run before and will made the
23 * call.)
24 */
25#define CPU_CLOCKUPDATE(otime, ntime) \
26	do { \
27	if(i586_ctr_rate) { \
28		disable_intr(); \
29		i586_ctr_bias = i586_last_tick; \
30		*(otime) = *(ntime); \
31		enable_intr(); \
32	} else { \
33		*(otime) = *(ntime); \
34	} \
35	} while(0)
36
37#define	CPU_THISTICKLEN(dflt) cpu_thisticklen(dflt)
38#else
39#define CPU_CLOCKUPDATE(otime, ntime) \
40		(*(otime) = *(ntime))
41#define CPU_THISTICKLEN(dflt) dflt
42#endif
43
44#define		I586_CTR_RATE_SHIFT	8
45
46#if defined(KERNEL) && !defined(LOCORE)
47#include <sys/cdefs.h>
48#include <machine/frame.h>
49
50/*
51 * i386 to clock driver interface.
52 * XXX almost all of it is misplaced.  i586 stuff is done in isa/clock.c
53 * and isa stuff is done in i386/microtime.s and i386/support.s.
54 */
55extern int	adjkerntz;
56extern int	disable_rtc_set;
57#ifdef I586_CPU
58extern unsigned	i586_ctr_rate;	/* fixed point */
59extern long long i586_last_tick;
60extern long long i586_ctr_bias;
61#endif
62extern int 	timer0_max_count;
63extern u_int 	timer0_overflow_threshold;
64extern u_int 	timer0_prescaler_count;
65
66#ifdef I586_CPU
67void	calibrate_cyclecounter __P((void));
68#endif
69
70#ifdef I586_CPU
71static __inline u_long
72cpu_thisticklen(u_long dflt)
73{
74	long long old;
75	long rv;
76
77	if (i586_ctr_rate) {
78		old = i586_last_tick;
79		I586_CYCLECTR(i586_last_tick);
80		rv = ((i586_last_tick - old) << I586_CTR_RATE_SHIFT)
81			/ i586_ctr_rate;
82	} else {
83		rv = dflt;
84	}
85	return rv;
86}
87#endif
88
89/*
90 * Driver to clock driver interface.
91 */
92void	DELAY __P((int usec));
93int	acquire_timer0 __P((int rate,
94			    void (*function)(struct clockframe *frame)));
95int	acquire_timer2 __P((int mode));
96int	release_timer0 __P((void));
97int	release_timer2 __P((void));
98int	sysbeep __P((int pitch, int period));
99
100#endif /* KERNEL && !LOCORE */
101
102#endif /* !_MACHINE_CLOCK_H_ */
103