| | 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 | #ifndef _KERN_TIMER_H_ |
| | 60 | #define _KERN_TIMER_H_ |
| | 61 | |
| | 62 | #include <kern/kern_types.h> |
| | 63 | |
| | 64 | /* |
| | 65 | * Some platforms have very expensive timebase routines. An optimization |
| | 66 | * is to avoid switching timers on kernel exit/entry, which results in all |
| | 67 | * time billed to the system timer. However, when exposed to userspace, |
| | 68 | * we report as user time to indicate that work was done on behalf of |
| | 69 | * userspace. |
| | 70 | * |
| | 71 | * Although this policy is implemented as a global variable, we snapshot it |
| | 72 | * at key points in the thread structure (when the thread is locked and |
| | 73 | * executing in the kernel) to avoid imbalances. |
| | 74 | */ |
| | 75 | extern int precise_user_kernel_time; |
| | 76 | |
| | 77 | /* |
| | 78 | * thread must be locked, or be the current executing thread, so that |
| | 79 | * it doesn't transition from user to kernel while updating the |
| | 80 | * thread-local value (or in kernel debugger context). In the future, |
| | 81 | * we make take into account task-level or thread-level policy. |
| | 82 | */ |
| | 83 | #define use_precise_user_kernel_time(thread) ( precise_user_kernel_time ) |
| | 84 | |
| | 85 | /* |
| | 86 | * Definitions for high resolution timers. A check |
| | 87 | * word on the high portion allows atomic updates. |
| | 88 | */ |
| | 89 | |
| | 90 | struct timer { |
| | 91 | uint64_t tstamp; |
| | 92 | #if defined(__LP64__) |
| | 93 | uint64_t all_bits; |
| | 94 | #else |
| | 95 | uint32_t low_bits; |
| | 96 | uint32_t high_bits; |
| | 97 | uint32_t high_bits_check; |
| | 98 | #endif |
| | 99 | }; |
| | 100 | |
| | 101 | typedef struct timer timer_data_t, *timer_t; |
| | 102 | |
| | 103 | /* |
| | 104 | * Exported kernel interface to timers |
| | 105 | */ |
| | 106 | |
| | 107 | /* Start a timer by setting the timestamp */ |
| | 108 | extern void timer_start( |
| | 109 | timer_t timer, |
| | 110 | uint64_t tstamp); |
| | 111 | |
| | 112 | /* Stop a timer by updating from the timestamp */ |
| | 113 | extern void timer_stop( |
| | 114 | timer_t timer, |
| | 115 | uint64_t tstamp); |
| | 116 | |
| | 117 | /* Update the timer and start a new one */ |
| | 118 | extern void timer_switch( |
| | 119 | timer_t timer, |
| | 120 | uint64_t tstamp, |
| | 121 | timer_t new_timer); |
| | 122 | |
| | 123 | /* Update the thread timer at an event */ |
| | 124 | extern void thread_timer_event( |
| | 125 | uint64_t tstamp, |
| | 126 | timer_t new_timer); |
| | 127 | |
| | 128 | /* Initialize a timer */ |
| | 129 | extern void timer_init( |
| | 130 | timer_t timer); |
| | 131 | |
| | 132 | /* Update a saved timer value and return delta to current value */ |
| | 133 | extern uint64_t timer_delta( |
| | 134 | timer_t timer, |
| | 135 | uint64_t *save); |
| | 136 | |
| | 137 | /* Advance a timer by a 64 bit value */ |
| | 138 | extern void timer_advance( |
| | 139 | timer_t timer, |
| | 140 | uint64_t delta); |
| | 141 | |
| | 142 | /* |
| | 143 | * Exported hardware interface to timers |
| | 144 | */ |
| | 145 | |
| | 146 | /* Read timer value */ |
| | 147 | #if defined(__LP64__) |
| | 148 | static inline uint64_t timer_grab( |
| | 149 | timer_t timer) |
| | 150 | { |
| | 151 | return timer->all_bits; |
| | 152 | } |
| | 153 | #else |
| | 154 | extern uint64_t timer_grab( |
| | 155 | timer_t timer); |
| | 156 | |
| | 157 | /* Update timer value */ |
| | 158 | extern void timer_update( |
| | 159 | timer_t timer, |
| | 160 | uint32_t new_high, |
| | 161 | uint32_t new_low); |
| | 162 | #endif /* defined(__LP64__) */ |
| | 163 | |
| | 164 | #endif /* _KERN_TIMER_H_ */ |
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