1/*
2 * Copyright (c) 2014 Apple Computer, 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
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27 */
28
29#ifndef __IOKIT_IOINTERRUPTACCOUNTING_H
30#define __IOKIT_IOINTERRUPTACCOUNTING_H
31
32#include <IOKit/IOReportTypes.h>
33
34/*
35 * This header contains definitions that will be needed by userspace clients of the interrupt accounting
36 * mechanisms.
37 */
38
39#define IA_INDEX_MAX (255)
40#define IA_INDEX_MASK (0xFFULL)
41#define IA_STATISTIC_INDEX_SHIFT (0ULL)
42#define IA_INTERRUPT_INDEX_SHIFT (16ULL)
43
44/*
45 * For the moment, the indices aren't preprocessor visible, so any changes to this code will need to be
46 * careful to ensure that the defined number of statistics matches (or is greater than) the actual number
47 * of statistics, to avoid channel ID collisions... because that would be bad.
48 */
49#define IA_NUM_INTERRUPT_ACCOUNTING_STATISTICS (10)
50
51/*
52 * Channel ID related definitions. These serve to denote the namespace of interrupt accounting in the
53 * context of IOReporter-based clients. Interrupt accounting distinguishes between interrupts based on
54 * the nub the interrupt was registered relative to, and the nub relative interrupt index (i.e, the
55 * namespace for interrupt accounting is {nub ID, interrupt index}). IOReporting already knows about
56 * nubs (in the context of IOService), however it has no built in knowledge of interrupt accounting.
57 * As a result of this, it is the responsibility of the IOReporting client to request any desired
58 * statistics on a per-index basis (i.e, if you want to get the first level interrupt count for all
59 * interrupts, you must express an interest in the first level interrupt count statistic for index 0, 1,
60 * 2, and so on, to a reasonable maximum).
61 */
62
63/*
64 * These delimit the channel ID namespace for interrupt accounting.
65 */
66#define IA_BASE_CHANNEL_ID IOREPORT_MAKEID('I', 'n', 't', 'r', 0, 0, 0, 0) /* First valid channel ID */
67#define IA_MAX_CHANNEL_ID IOREPORT_MAKEID('I', 'n', 't', 'r', 0xFF, 0xFF, 0xFF, 0xFF) /* Last valid channel ID */
68
69/*
70 * Given a nub-relative interrupt index (an index into the interrupt specifiers), and the index of a
71 * interrupt accounting statistic, returns the channel id for that statistic.
72 */
73#define IA_GET_CHANNEL_ID(interruptIndex, statisticIndex) \
74 ((IA_BASE_CHANNEL_ID) + \
75 ((interruptIndex % IA_INDEX_MASK) << IA_INTERRUPT_INDEX_SHIFT) + \
76 ((statisticIndex % IA_INDEX_MASK) << IA_STATISTIC_INDEX_SHIFT))
77
78/*
79 * Extracts the interrupt index, given a channel ID.
80 */
81#define IA_GET_INTERRUPT_INDEX(channelID) \
82 (((channelID - IA_BASE_CHANNEL_ID) >> IA_INTERRUPT_INDEX_SHIFT) % IA_INDEX_MASK)
83
84/*
85 * Extracts the statistic index, given a channel ID.
86 */
87#define IA_GET_STATISTIC_INDEX(channelID) \
88 (((channelID - IA_BASE_CHANNEL_ID) >> IA_STATISTIC_INDEX_SHIFT) % IA_INDEX_MASK)
89
90/*
91 * This enum defines the basic statistics we gather for each interrupt. Currently, the information
92 * we gather falls into roughly three buckets: interrupt related (counts, times), scheduler related
93 * (thread wakeups), and power related (package/cpu state changes).
94 *
95 * First Level Count: This represents the number of times that this interrupt has fired (more
96 * specifically, the number of times we have run the handler we expect to run in interrupt context).
97 *
98 * Second Level Count: This represents the number of times we have run any second level handler for
99 * this interrupt (more specifically, the handler we expect to be run in the regular kernel context).
100 *
101 * First Level Time: This represents the aggregate time spent running the first level handler. For
102 * some interrupts, this value will be 0, as this is not meant to track time spent running generic
103 * IOKit code for the interrupt (i.e, IOInterruptEventSource code), but instead any custom code run
104 * at the interrupt context (i.e, the filter installed for an IOFilterInterruptEventSource).
105 *
106 * Second Level CPU Time: This represents the aggregate time spent actually running the second level
107 * handler on the CPU. As the second level handler may block or be preempted, it is meaningful to
108 * distinguish this from the system time spent handling the interrupt. As was the case for the
109 * first level handler, this does not attempt to track the time spent running generic IOKit code
110 * (i.e, IOInterruptEventSource code or IOWorkLoop code), but instead attempts to track the time
111 * spent running the handler that was installed.
112 *
113 * Second Level System Time: This represents the aggregate time spent in the second level handler;
114 * this will include time where the handler was blocked or had been preempted. This should equate
115 * to the wall time spent handling an interrupt (as long as we don't allow the system to go to
116 * sleep while a second level handler is running).
117 *
118 * No Thread Wakeups: The number of times that the interrupt did not attempt to wake up a thread
119 * (typically the work loop for the interrupt source is woken up).
120 *
121 * Total Thread Wakeups: The aggregate number of threads (non-unique) woken up by the interrupt.
122 * If no threads were actually woken up for an interrupt (i.e, the work loop thread was already
123 * runnable), this value will not change.
124 *
125 * Package Wakeups: The number of times that this interrupt woke up the package (as defined by the
126 * scheduler).
127 *
128 * CPU Wakeups: The number of times that this interrupt woke up a CPU (forcing it to go through the
129 * reset path).
130 *
131 * Idle Exits: The number of times that this interrupt forced a CPU out of the idle loop (the CPU
132 * had to exit an idle state to handle the interrupt, but it did not need to go through the reset
133 * path).
134 */
135enum {
136 kInterruptAccountingFirstLevelCountIndex = 0, /* Number of times we invoked the top level handler */
137 kInterruptAccountingSecondLevelCountIndex, /* Number of times we invoked the workloop action */
138 kInterruptAccountingFirstLevelTimeIndex, /* Time spent in the top level handler, if one was installed */
139 kInterruptAccountingSecondLevelCPUTimeIndex, /* CPU time spent in the workloop action */
140 kInterruptAccountingSecondLevelSystemTimeIndex, /* System time spent in the workloop action */
141 kInterruptAccountingNoThreadWakeupsIndex, /* Number of first level (filter) invocations that did not wake up a thread */
142 kInterruptAccountingTotalThreadWakeupsIndex, /* Number of actual thread wakeups caused by this interrupt */
143 kInterruptAccountingPackageWakeupsIndex, /* Number of times this interrupt woke up the package */
144 kInterruptAccountingCPUWakeupsIndex, /* Number of times this interrupt woke up a CPU */
145 kInterruptAccountingIdleExitsIndex, /* Number of times this interrupt forced a CPU out of the idle loop */
146 kInterruptAccountingInvalidStatisticIndex /* Sentinel value for checking for a nonsensical index */
147};
148
149/*
150 * IOReporting group name; exposed publicly for the purpose of getting channels by group
151 * name; other strings (subgroup names, statistic names) are not exposed, as we may want
152 * to change them in the future.
153 */
154#define kInterruptAccountingGroupName "Interrupt Statistics (by index)"
155
156#endif /* __IOKIT_IOINTERRUPTACCOUNTING_PRIVATE_H */
157