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#include <mach/kern_return.h>
60#include <mach/port.h>
61#include <kern/queue.h>
62#include <kern/processor.h>
63#include <kern/thread.h>
64#include <kern/sched_prim.h>
65#include <kern/timer.h>
66
67int precise_user_kernel_time = 1;
68
69/*
70 *	timer_init initializes a timer.
71 */
72void
73timer_init(
74	timer_t		timer)
75{
76	timer->tstamp = 0;
77#if	defined(__LP64__)
78	timer->all_bits = 0;
79#else
80	timer->low_bits = 0;
81	timer->high_bits = 0;
82	timer->high_bits_check = 0;
83#endif	/* defined(__LP64__) */
84}
85
86/*
87 *	Calculate the difference between a timer
88 *	and saved value, and update the saved value.
89 */
90uint64_t
91timer_delta(
92	timer_t		timer,
93	uint64_t	*save)
94{
95	uint64_t	new, old = *save;
96
97	*save = new = timer_grab(timer);
98
99	return (new - old);
100}
101
102void
103timer_advance(
104	timer_t		timer,
105	uint64_t	delta)
106{
107#if	defined(__LP64__)
108	timer->all_bits += delta;
109#else
110	uint64_t	low;
111
112	low = delta + timer->low_bits;
113	if (low >> 32)
114		timer_update(timer, (uint32_t)(timer->high_bits + (low >> 32)), (uint32_t)low);
115	else
116		timer->low_bits = (uint32_t)low;
117#endif 	/* defined(__LP64__) */
118}
119
120void
121timer_start(
122	timer_t		timer,
123	uint64_t	tstamp)
124{
125	timer->tstamp = tstamp;
126}
127
128void
129timer_stop(
130	timer_t		timer,
131	uint64_t	tstamp)
132{
133	timer_advance(timer, tstamp - timer->tstamp);
134}
135
136/*
137 *	Update the timer and start a new one.
138 */
139void
140timer_switch(
141	timer_t			timer,
142	uint64_t		tstamp,
143	timer_t			new_timer)
144{
145	timer_advance(timer, tstamp - timer->tstamp);
146	new_timer->tstamp = tstamp;
147}
148
149/*
150 *	Update the current thread timer and
151 *	start the new timer.  Requires a current
152 *	and new timer.
153 *
154 *	Called with interrupts disabled.
155 */
156void
157thread_timer_event(
158	uint64_t		tstamp,
159	timer_t			new_timer)
160{
161	processor_t		processor = current_processor();
162	timer_t			timer;
163
164	/*
165	 *	Update current timer.
166	 */
167	timer = PROCESSOR_DATA(processor, thread_timer);
168	timer_advance(timer, tstamp - timer->tstamp);
169
170	/*
171	 *	Start new timer.
172	 */
173	PROCESSOR_DATA(processor, thread_timer) = new_timer;
174	new_timer->tstamp = tstamp;
175}
176