1/*
2 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
49 *  School of Computer Science
50 *  Carnegie Mellon University
51 *  Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56/*
57 */
58
59#ifndef	_KERN_TIMER_H_
60#define _KERN_TIMER_H_
61
62#include <stat_time.h>
63
64#include <kern/kern_types.h>
65
66/*
67 *	Definitions for high resolution timers.  A check
68 *	word on the high portion allows atomic updates.
69 */
70
71struct timer {
72#if	!STAT_TIME
73	uint64_t	tstamp;
74#endif	/* STAT_TIME */
75	uint32_t	low_bits;
76	uint32_t	high_bits;
77	uint32_t	high_bits_check;
78};
79
80typedef struct timer	timer_data_t, *timer_t;
81
82/*
83 *	Exported kernel interface to timers
84 */
85
86#if	STAT_TIME
87
88#include <kern/macro_help.h>
89
90/* Advance a timer by a 32 bit value */
91#define TIMER_BUMP(timer, ticks)								\
92MACRO_BEGIN														\
93	uint32_t	old_low, low;									\
94																\
95	old_low = (timer)->low_bits;								\
96	low = old_low + (ticks);									\
97	if (low < old_low)											\
98		timer_update((timer), (timer)->high_bits + 1, low);		\
99	else														\
100		(timer)->low_bits = low;								\
101MACRO_END
102
103#define timer_start(timer, tstamp)
104#define timer_stop(timer, tstamp)
105#define timer_switch(timer, tstamp, new_timer)
106#define thread_timer_event(tstamp, new_timer)
107
108#else	/* STAT_TIME */
109
110#define	TIMER_BUMP(timer, ticks)
111
112/* Start a timer by setting the timestamp */
113extern void		timer_start(
114					timer_t		timer,
115					uint64_t	tstamp);
116
117/* Stop a timer by updating from the timestamp */
118extern void		timer_stop(
119					timer_t		timer,
120					uint64_t	tstamp);
121
122/* Update the timer and start a new one */
123extern void		timer_switch(
124					timer_t		timer,
125					uint64_t	tstamp,
126					timer_t		new_timer);
127
128/* Update the thread timer at an event */
129extern void		thread_timer_event(
130					uint64_t	tstamp,
131					timer_t		new_timer);
132
133#endif	/* STAT_TIME */
134
135/* Initialize a timer */
136extern void		timer_init(
137					timer_t		timer);
138
139/* Update a saved timer value and return delta to current value */
140extern uint64_t	timer_delta(
141					timer_t		timer,
142					uint64_t	*save);
143
144/* Advance a timer by a 64 bit value */
145extern void		timer_advance(
146					timer_t		timer,
147					uint64_t	delta);
148
149/*
150 *	Exported hardware interface to timers
151 */
152
153/* Read timer value */
154extern uint64_t	timer_grab(
155					timer_t		timer);
156
157/* Update timer value */
158extern void		timer_update(
159					timer_t		timer,
160					uint32_t	new_high,
161					uint32_t	new_low);
162
163#endif	/* _KERN_TIMER_H_ */
164