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 <machine_timer_routines.h>
60
61#include <mach/kern_return.h>
62#include <mach/port.h>
63#include <kern/queue.h>
64#include <kern/processor.h>
65#include <kern/thread.h>
66#include <kern/sched_prim.h>
67#include <kern/timer.h>
68
69#if CONFIG_EMBEDDED
70int precise_user_kernel_time = 0;
71#else
72int precise_user_kernel_time = 1;
73#endif
74
75/*
76 *	timer_init initializes a timer.
77 */
78void
79timer_init(
80	timer_t		timer)
81{
82	timer->tstamp = 0;
83#if	defined(__LP64__)
84	timer->all_bits = 0;
85#else
86	timer->low_bits = 0;
87	timer->high_bits = 0;
88	timer->high_bits_check = 0;
89#endif	/* defined(__LP64__) */
90}
91
92/*
93 *	Calculate the difference between a timer
94 *	and saved value, and update the saved value.
95 */
96uint64_t
97timer_delta(
98	timer_t		timer,
99	uint64_t	*save)
100{
101	uint64_t	new, old = *save;
102
103	*save = new = timer_grab(timer);
104
105	return (new - old);
106}
107
108void
109timer_advance(
110	timer_t		timer,
111	uint64_t	delta)
112{
113#if	defined(__LP64__)
114	timer->all_bits += delta;
115#else
116	uint64_t	low;
117
118	low = delta + timer->low_bits;
119	if (low >> 32)
120		timer_update(timer, (uint32_t)(timer->high_bits + (low >> 32)), (uint32_t)low);
121	else
122		timer->low_bits = (uint32_t)low;
123#endif 	/* defined(__LP64__) */
124}
125
126void
127timer_start(
128	timer_t		timer,
129	uint64_t	tstamp)
130{
131	timer->tstamp = tstamp;
132}
133
134void
135timer_stop(
136	timer_t		timer,
137	uint64_t	tstamp)
138{
139	timer_advance(timer, tstamp - timer->tstamp);
140}
141
142/*
143 *	Update the timer and start a new one.
144 */
145void
146timer_switch(
147	timer_t			timer,
148	uint64_t		tstamp,
149	timer_t			new_timer)
150{
151	timer_advance(timer, tstamp - timer->tstamp);
152	new_timer->tstamp = tstamp;
153}
154
155#if	MACHINE_TIMER_ROUTINES
156
157/*
158 *	Machine-dependent code implements the timer event routine.
159 */
160
161#else	/* MACHINE_TIMER_ROUTINES */
162
163/*
164 *	Update the current thread timer and
165 *	start the new timer.  Requires a current
166 *	and new timer.
167 *
168 *	Called with interrupts disabled.
169 */
170void
171thread_timer_event(
172	uint64_t		tstamp,
173	timer_t			new_timer)
174{
175	processor_t		processor = current_processor();
176	timer_t			timer;
177
178	/*
179	 *	Update current timer.
180	 */
181	timer = PROCESSOR_DATA(processor, thread_timer);
182	timer_advance(timer, tstamp - timer->tstamp);
183
184	/*
185	 *	Start new timer.
186	 */
187	PROCESSOR_DATA(processor, thread_timer) = new_timer;
188	new_timer->tstamp = tstamp;
189}
190
191#endif	/* MACHINE_TIMER_ROUTINES */
192