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Diffstat (limited to 'sys/sys/timetc.h')
| -rw-r--r-- | sys/sys/timetc.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/sys/sys/timetc.h b/sys/sys/timetc.h new file mode 100644 index 0000000..ce81c34 --- /dev/null +++ b/sys/sys/timetc.h @@ -0,0 +1,107 @@ +/* $OpenBSD: timetc.h,v 1.10 2019/10/26 21:16:38 cheloha Exp $ */ + +/* + * Copyright (c) 2000 Poul-Henning Kamp <phk@FreeBSD.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* + * If we meet some day, and you think this stuff is worth it, you + * can buy me a beer in return. Poul-Henning Kamp + */ + +#ifndef _SYS_TIMETC_H_ +#define _SYS_TIMETC_H_ + +#ifndef _KERNEL +#error "no user-serviceable parts inside" +#endif + +#include <sys/queue.h> + +/*- + * `struct timecounter' is the interface between the hardware which implements + * a timecounter and the MI code which uses this to keep track of time. + * + * A timecounter is a binary counter which has two properties: + * * it runs at a fixed, known frequency. + * * it has sufficient bits to not roll over in less than approximately + * max(2 msec, 2/HZ seconds). (The value 2 here is really 1 + delta, + * for some indeterminate value of delta.) + */ + +struct timecounter; +typedef u_int timecounter_get_t(struct timecounter *); +typedef void timecounter_pps_t(struct timecounter *); + +/* + * Locks used to protect struct members in this file: + * I immutable after initialization + * t tc_lock + * w windup_mtx + */ + +struct timecounter { + timecounter_get_t *tc_get_timecount; /* [I] */ + /* + * This function reads the counter. It is not required to + * mask any unimplemented bits out, as long as they are + * constant. + */ + timecounter_pps_t *tc_poll_pps; /* [I] */ + /* + * This function is optional. It will be called whenever the + * timecounter is rewound, and is intended to check for PPS + * events. Normal hardware does not need it but timecounters + * which latch PPS in hardware (like sys/pci/xrpu.c) do. + */ + u_int tc_counter_mask; /* [I] */ + /* This mask should mask off any unimplemented bits. */ + u_int64_t tc_frequency; /* [I] */ + /* Frequency of the counter in Hz. */ + char *tc_name; /* [I] */ + /* Name of the timecounter. */ + int tc_quality; /* [I] */ + /* + * Used to determine if this timecounter is better than + * another timecounter higher means better. Negative + * means "only use at explicit request". + */ + void *tc_priv; /* [I] */ + /* Pointer to the timecounter's private parts. */ + SLIST_ENTRY(timecounter) tc_next; /* [I] */ + /* Pointer to the next timecounter. */ + int64_t tc_freq_adj; /* [tw] */ + /* Current frequency adjustment. */ + u_int64_t tc_precision; /* [I] */ + /* Precision of the counter. Computed in tc_init(). */ +}; + +struct rwlock; +extern struct rwlock tc_lock; + +extern struct timecounter *timecounter; + +u_int64_t tc_getfrequency(void); +u_int64_t tc_getprecision(void); +void tc_init(struct timecounter *tc); +void tc_setclock(const struct timespec *ts); +void tc_setrealtimeclock(const struct timespec *ts); +void tc_ticktock(void); +void inittimecounter(void); +int sysctl_tc(int *, u_int, void *, size_t *, void *, size_t); +void tc_adjfreq(int64_t *, int64_t *); +void tc_adjtime(int64_t *, int64_t *); + +#endif /* !_SYS_TIMETC_H_ */ |