1 /* $OpenBSD: timetc.h,v 1.14 2023/02/04 19:19:35 cheloha Exp $ */ 2 3 /* 4 * Copyright (c) 2000 Poul-Henning Kamp <phk@FreeBSD.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 /* 20 * If we meet some day, and you think this stuff is worth it, you 21 * can buy me a beer in return. Poul-Henning Kamp 22 */ 23 24 #ifndef _SYS_TIMETC_H_ 25 #define _SYS_TIMETC_H_ 26 27 #if !defined(_KERNEL) && !defined(_LIBC) 28 #error "no user-serviceable parts inside" 29 #endif 30 31 #include <machine/timetc.h> 32 #include <sys/queue.h> 33 34 /*- 35 * `struct timecounter' is the interface between the hardware which implements 36 * a timecounter and the MI code which uses this to keep track of time. 37 * 38 * A timecounter is a binary counter which has two properties: 39 * * it runs at a fixed, known frequency. 40 * * it has sufficient bits to not roll over in less than approximately 41 * max(2 msec, 2/HZ seconds). (The value 2 here is really 1 + delta, 42 * for some indeterminate value of delta.) 43 */ 44 45 struct timecounter; 46 typedef u_int timecounter_get_t(struct timecounter *); 47 48 /* 49 * Locks used to protect struct members in this file: 50 * I immutable after initialization 51 * T tc_lock 52 * W windup_mtx 53 */ 54 55 struct timecounter { 56 timecounter_get_t *tc_get_timecount; /* [I] */ 57 /* 58 * This function reads the counter. It is not required to 59 * mask any unimplemented bits out, as long as they are 60 * constant. 61 */ 62 u_int tc_counter_mask; /* [I] */ 63 /* This mask should mask off any unimplemented bits. */ 64 u_int64_t tc_frequency; /* [I] */ 65 /* Frequency of the counter in Hz. */ 66 char *tc_name; /* [I] */ 67 /* Name of the timecounter. */ 68 int tc_quality; /* [I] */ 69 /* 70 * Used to determine if this timecounter is better than 71 * another timecounter higher means better. Negative 72 * means "only use at explicit request". 73 */ 74 void *tc_priv; /* [I] */ 75 /* Pointer to the timecounter's private parts. */ 76 int tc_user; /* [I] */ 77 /* Expose this timecounter to userland. */ 78 SLIST_ENTRY(timecounter) tc_next; /* [I] */ 79 /* Pointer to the next timecounter. */ 80 int64_t tc_freq_adj; /* [T,W] */ 81 /* Current frequency adjustment. */ 82 u_int64_t tc_precision; /* [I] */ 83 /* Precision of the counter. Computed in tc_init(). */ 84 }; 85 86 struct timekeep { 87 /* set at initialization */ 88 uint32_t tk_version; /* version number */ 89 90 /* timehands members */ 91 uint64_t tk_scale; 92 u_int tk_offset_count; 93 struct bintime tk_offset; 94 struct bintime tk_naptime; 95 struct bintime tk_boottime; 96 volatile u_int tk_generation; 97 98 /* timecounter members */ 99 int tk_user; 100 u_int tk_counter_mask; 101 }; 102 #define TK_VERSION 0 103 104 struct rwlock; 105 extern struct rwlock tc_lock; 106 107 extern struct timecounter *timecounter; 108 109 extern struct uvm_object *timekeep_object; 110 extern struct timekeep *timekeep; 111 112 u_int64_t tc_getfrequency(void); 113 u_int64_t tc_getprecision(void); 114 void tc_init(struct timecounter *tc); 115 void tc_reset_quality(struct timecounter *, int); 116 void tc_setclock(const struct timespec *ts); 117 void tc_setrealtimeclock(const struct timespec *ts); 118 void tc_ticktock(void); 119 void inittimecounter(void); 120 int sysctl_tc(int *, u_int, void *, size_t *, void *, size_t); 121 void tc_adjfreq(int64_t *, int64_t *); 122 void tc_adjtime(int64_t *, int64_t *); 123 124 #endif /* !_SYS_TIMETC_H_ */ 125