Annotation of sys/sys/timetc.h, Revision 1.1.1.1
1.1 nbrk 1: /*-
2: * ----------------------------------------------------------------------------
3: * "THE BEER-WARE LICENSE" (Revision 42):
4: * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
5: * can do whatever you want with this stuff. If we meet some day, and you think
6: * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
7: * ----------------------------------------------------------------------------
8: *
9: * $OpenBSD: timetc.h,v 1.2 2006/10/30 20:19:33 otto Exp $
10: * $FreeBSD: src/sys/sys/timetc.h,v 1.57 2003/04/10 23:07:24 des Exp $
11: */
12:
13: #ifndef _SYS_TIMETC_H_
14: #define _SYS_TIMETC_H_
15:
16: #ifndef _KERNEL
17: #error "no user-serviceable parts inside"
18: #endif
19:
20: /*-
21: * `struct timecounter' is the interface between the hardware which implements
22: * a timecounter and the MI code which uses this to keep track of time.
23: *
24: * A timecounter is a binary counter which has two properties:
25: * * it runs at a fixed, known frequency.
26: * * it has sufficient bits to not roll over in less than approximately
27: * max(2 msec, 2/HZ seconds). (The value 2 here is really 1 + delta,
28: * for some indeterminate value of delta.)
29: */
30:
31: struct timecounter;
32: typedef u_int timecounter_get_t(struct timecounter *);
33: typedef void timecounter_pps_t(struct timecounter *);
34:
35: struct timecounter {
36: timecounter_get_t *tc_get_timecount;
37: /*
38: * This function reads the counter. It is not required to
39: * mask any unimplemented bits out, as long as they are
40: * constant.
41: */
42: timecounter_pps_t *tc_poll_pps;
43: /*
44: * This function is optional. It will be called whenever the
45: * timecounter is rewound, and is intended to check for PPS
46: * events. Normal hardware does not need it but timecounters
47: * which latch PPS in hardware (like sys/pci/xrpu.c) do.
48: */
49: u_int tc_counter_mask;
50: /* This mask should mask off any unimplemented bits. */
51: u_int64_t tc_frequency;
52: /* Frequency of the counter in Hz. */
53: char *tc_name;
54: /* Name of the timecounter. */
55: int tc_quality;
56: /*
57: * Used to determine if this timecounter is better than
58: * another timecounter higher means better. Negative
59: * means "only use at explicit request".
60: */
61: void *tc_priv;
62: /* Pointer to the timecounter's private parts. */
63: struct timecounter *tc_next;
64: /* Pointer to the next timecounter. */
65: int64_t tc_freq_adj;
66: /* Current frequency adjustment. */
67: };
68:
69: extern struct timecounter *timecounter;
70:
71: u_int64_t tc_getfrequency(void);
72: void tc_init(struct timecounter *tc);
73: void tc_setclock(struct timespec *ts);
74: void tc_ticktock(void);
75: void inittimecounter(void);
76: int sysctl_tc(int *, u_int, void *, size_t *, void *, size_t);
77: int tc_adjfreq(int64_t *, int64_t *);
78:
79: #endif /* !_SYS_TIMETC_H_ */
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