xref: /xnu-11215/osfmk/kern/timer.c (revision 5c2921b0)
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  [email protected]
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 #include <machine/config.h>
66 
67 void
timer_init(timer_t timer)68 timer_init(timer_t timer)
69 {
70 	memset(timer, 0, sizeof(*timer));
71 }
72 
73 static void
timer_advance(timer_t timer,uint64_t delta)74 timer_advance(timer_t timer, uint64_t delta)
75 {
76 #if defined(__LP64__)
77 	timer->all_bits += delta;
78 #else /* defined(__LP64__) */
79 	extern void timer_advance_internal_32(timer_t timer, uint32_t high,
80 	    uint32_t low);
81 	uint64_t low = delta + timer->low_bits;
82 	if (low >> 32) {
83 		timer_advance_internal_32(timer,
84 		    (uint32_t)(timer->high_bits + (low >> 32)), (uint32_t)low);
85 	} else {
86 		timer->low_bits = (uint32_t)low;
87 	}
88 #endif /* defined(__LP64__) */
89 }
90 
91 void
timer_start(timer_t timer,uint64_t tstamp)92 timer_start(timer_t timer, uint64_t tstamp)
93 {
94 	timer->tstamp = tstamp;
95 }
96 
97 void
timer_stop(timer_t timer,uint64_t tstamp)98 timer_stop(timer_t timer, uint64_t tstamp)
99 {
100 	timer_advance(timer, tstamp - timer->tstamp);
101 }
102 
103 void
timer_update(timer_t timer,uint64_t tstamp)104 timer_update(timer_t timer, uint64_t tstamp)
105 {
106 	timer_advance(timer, tstamp - timer->tstamp);
107 	timer->tstamp = tstamp;
108 }
109