1/*
2 * Copyright (c) 2000-2018 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#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#if CONFIG_EMBEDDED
66int precise_user_kernel_time = 0;
67#else
68int precise_user_kernel_time = 1;
69#endif
70
71void
72timer_init(timer_t timer)
73{
74 memset(timer, 0, sizeof(*timer));
75}
76
77uint64_t
78timer_delta(timer_t timer, uint64_t *prev_in_cur_out)
79{
80 uint64_t old = *prev_in_cur_out;
81 uint64_t new = *prev_in_cur_out = timer_grab(timer);
82 return (new - old);
83}
84
85static void
86timer_advance(timer_t timer, uint64_t delta)
87{
88#if defined(__LP64__)
89 timer->all_bits += delta;
90#else /* defined(__LP64__) */
91 extern void timer_advance_internal_32(timer_t timer, uint32_t high,
92 uint32_t low);
93 uint64_t low = delta + timer->low_bits;
94 if (low >> 32) {
95 timer_advance_internal_32(timer,
96 (uint32_t)(timer->high_bits + (low >> 32)), (uint32_t)low);
97 } else {
98 timer->low_bits = (uint32_t)low;
99 }
100#endif /* defined(__LP64__) */
101}
102
103void
104timer_start(timer_t timer, uint64_t tstamp)
105{
106 timer->tstamp = tstamp;
107}
108
109void
110timer_stop(timer_t timer, uint64_t tstamp)
111{
112 timer_advance(timer, tstamp - timer->tstamp);
113}
114
115void
116timer_update(timer_t timer, uint64_t tstamp)
117{
118 timer_advance(timer, tstamp - timer->tstamp);
119 timer->tstamp = tstamp;
120}
121
122void
123timer_switch(timer_t timer, uint64_t tstamp, timer_t new_timer)
124{
125 timer_advance(timer, tstamp - timer->tstamp);
126 new_timer->tstamp = tstamp;
127}
128
129/*
130 * Update the current processor's thread timer with `tstamp` and switch the
131 * processor's thread timer to `new_timer`.
132 *
133 * Called with interrupts disabled.
134 */
135void
136processor_timer_switch_thread(uint64_t tstamp, timer_t new_timer)
137{
138 processor_t processor = current_processor();
139 timer_t timer;
140
141 /* Update current timer. */
142 timer = PROCESSOR_DATA(processor, thread_timer);
143 timer_advance(timer, tstamp - timer->tstamp);
144
145 /* Start new timer. */
146 PROCESSOR_DATA(processor, thread_timer) = new_timer;
147 new_timer->tstamp = tstamp;
148}
149