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1 /*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_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. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23 /*
24 * @OSF_COPYRIGHT@
25 */
26 /*
27 * Mach Operating System
28 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
29 * All Rights Reserved.
30 *
31 * Permission to use, copy, modify and distribute this software and its
32 * documentation is hereby granted, provided that both the copyright
33 * notice and this permission notice appear in all copies of the
34 * software, derivative works or modified versions, and any portions
35 * thereof, and that both notices appear in supporting documentation.
36 *
37 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
38 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
39 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
40 *
41 * Carnegie Mellon requests users of this software to return to
42 *
43 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
44 * School of Computer Science
45 * Carnegie Mellon University
46 * Pittsburgh PA 15213-3890
47 *
48 * any improvements or extensions that they make and grant Carnegie Mellon
49 * the rights to redistribute these changes.
50 */
51 /*
52 */
53
54 #include <stat_time.h>
55 #include <machine_timer_routines.h>
56
57 #include <mach/kern_return.h>
58 #include <mach/port.h>
59 #include <kern/queue.h>
60 #include <kern/processor.h>
61 #include <kern/thread.h>
62 #include <kern/sched_prim.h>
63 #include <kern/timer.h>
64
65 /*
66 * timer_init initializes a timer.
67 */
68 void
69 timer_init(
70 timer_t timer)
71 {
72 timer->low_bits = 0;
73 timer->high_bits = 0;
74 timer->high_bits_check = 0;
75 #if !STAT_TIME
76 timer->tstamp = 0;
77 #endif /* STAT_TIME */
78 }
79
80 /*
81 * Calculate the difference between a timer
82 * and saved value, and update the saved value.
83 */
84 uint64_t
85 timer_delta(
86 timer_t timer,
87 uint64_t *save)
88 {
89 uint64_t new, old = *save;
90
91 *save = new = timer_grab(timer);
92
93 return (new - old);
94 }
95
96 #if !STAT_TIME
97
98 /*
99 * Update the current timer (if any)
100 * and start the new timer, which
101 * could be either the same or NULL.
102 *
103 * Called with interrupts disabled.
104 */
105 void
106 timer_switch(
107 uint32_t tstamp,
108 timer_t new_timer)
109 {
110 processor_t processor = current_processor();
111 timer_t timer;
112 uint32_t old_low, low;
113
114 /*
115 * Update current timer.
116 */
117 timer = PROCESSOR_DATA(processor, current_timer);
118 if (timer != NULL) {
119 old_low = timer->low_bits;
120 low = old_low + tstamp - timer->tstamp;
121 if (low < old_low)
122 timer_update(timer, timer->high_bits + 1, low);
123 else
124 timer->low_bits = low;
125 }
126
127 /*
128 * Start new timer.
129 */
130 PROCESSOR_DATA(processor, current_timer) = new_timer;
131 if (new_timer != NULL)
132 new_timer->tstamp = tstamp;
133 }
134
135 #if MACHINE_TIMER_ROUTINES
136
137 /*
138 * Machine-dependent code implements the timer event routine.
139 */
140
141 #else /* MACHINE_TIMER_ROUTINES */
142
143 /*
144 * Update the current timer and start
145 * the new timer. Requires a current
146 * and new timer.
147 *
148 * Called with interrupts disabled.
149 */
150 void
151 timer_event(
152 uint32_t tstamp,
153 timer_t new_timer)
154 {
155 processor_t processor = current_processor();
156 timer_t timer;
157 uint32_t old_low, low;
158
159 /*
160 * Update current timer.
161 */
162 timer = PROCESSOR_DATA(processor, current_timer);
163 old_low = timer->low_bits;
164 low = old_low + tstamp - timer->tstamp;
165 if (low < old_low)
166 timer_update(timer, timer->high_bits + 1, low);
167 else
168 timer->low_bits = low;
169
170 /*
171 * Start new timer.
172 */
173 PROCESSOR_DATA(processor, current_timer) = new_timer;
174 new_timer->tstamp = tstamp;
175 }
176
177 #endif /* MACHINE_TIMER_ROUTINES */
178
179 #endif /* STAT_TIME */