clock.h revision 7090 
1/*
2 * Kernel interface to machine-dependent clock driver.
3 * Garrett Wollman, September 1994.
4 * This file is in the public domain.
5 */
6
7#ifndef _MACHINE_CLOCK_H_
8#define	_MACHINE_CLOCK_H_
9
10#ifdef I586_CPU
11	/*
12	 * This resets the CPU cycle counter to zero, to make our
13	 * job easier in microtime().  Some fancy ifdefs could speed
14	 * this up for Pentium-only kernels.
15	 * We want this to be done as close as possible to the actual
16	 * timer incrementing in hardclock(), because there is a window
17	 * between the two where the value is no longer valid.  Experimentation
18	 * may reveal a good precompensation to apply in microtime().
19	 */
20#define CPU_CLOCKUPDATE(otime, ntime) \
21	do { \
22	if(pentium_mhz) { \
23		__asm __volatile("cli\n" \
24				 "movl (%2),%%eax\n" \
25				 "movl %%eax,(%1)\n" \
26				 "movl 4(%2),%%eax\n" \
27				 "movl %%eax,4(%1)\n" \
28				 "movl $0x10,%%ecx\n" \
29				 "xorl %%eax,%%eax\n" \
30				 "movl %%eax,%%edx\n" \
31				 ".byte 0x0f, 0x30\n" \
32				 "sti\n" \
33				 "#%0%1%2" \
34				 : "=m"(*otime)	/* no outputs */ \
35				 : "c"(otime), "b"(ntime) /* fake input */ \
36				 : "ax", "cx", "dx"); \
37	} else { \
38		*(otime) = *(ntime); \
39	} \
40	} while(0)
41
42#else
43#define CPU_CLOCKUPDATE(otime, ntime) \
44		(*(otime) = *(ntime))
45#endif
46
47#if defined(KERNEL) && !defined(LOCORE)
48#include <sys/cdefs.h>
49#include <machine/frame.h>
50
51/*
52 * i386 to clock driver interface.
53 * XXX almost all of it is misplaced.  i586 stuff is done in isa/clock.c
54 * and isa stuff is done in i386/microtime.s and i386/support.s.
55 */
56extern int	adjkerntz;
57extern int	disable_rtc_set;
58#ifdef I586_CPU
59extern int	pentium_mhz;
60#endif
61extern int 	timer0_max_count;
62extern u_int 	timer0_overflow_threshold;
63extern u_int 	timer0_prescaler_count;
64
65#ifdef I586_CPU
66void	calibrate_cyclecounter __P((void));
67#endif
68void	clkintr __P((struct clockframe frame));
69void	rtcintr __P((struct clockframe frame));
70
71/*
72 * Driver to clock driver interface.
73 */
74void	DELAY __P((int usec));
75int	acquire_timer0 __P((int rate,
76			    void (*function)(struct clockframe *frame)));
77int	acquire_timer2 __P((int mode));
78int	release_timer0 __P((void));
79int	release_timer2 __P((void));
80int	sysbeep __P((int pitch, int period));
81
82#endif /* KERNEL && !LOCORE */
83
84#endif /* !_MACHINE_CLOCK_H_ */
85