1/*
2 * Copyright (c) 1998-2016 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
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16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
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23 * Please see the License for the specific language governing rights and
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27 */
28/*
29Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
30
31HISTORY
32 1999-4-15 Godfrey van der Linden(gvdl)
33 Created.
34*/
35#ifndef _IOKIT_IOFILTERINTERRUPTEVENTSOURCE_H
36#define _IOKIT_IOFILTERINTERRUPTEVENTSOURCE_H
37
38#include <IOKit/IOInterruptEventSource.h>
39
40class IOService;
41
42/*! @class IOFilterInterruptEventSource : public IOInterruptEventSource
43 @abstract Filtering varient of the $link IOInterruptEventSource.
44 @discussion An interrupt event source that calls the client to determine if a interrupt event needs to be scheduled on the work loop. A filter interrupt event source call's the client in the primary interrupt context, the client can then interrogate its hardware and determine if the interrupt needs to be processed yet.
45<br><br>
46 As the routine is called in the primary interrupt context great care must be taken in the writing of this routine. In general none of the generic IOKit environment is safe to call in this context. We intend this routine to be used by hardware that can interrogate its registers without destroying state. Primarily this variant of event sources will be used by drivers that share interrupts. The filter routine will determine if the interrupt is a real interrupt or a ghost and thus optimise the work thread context switch away.
47<br><br>
48If you are implementing 'SoftDMA' (or pseudo-DMA), you may not want the I/O Kit to automatically start your interrupt handler routine on your work loop when your filter routine returns true. In this case, you may choose to have your filter routine schedule the work on the work loop itself and then return false. If you do this, the interrupt will not be disabled in hardware and you could receive additional primary interrupts before your work loop–level service routine completes. Because this scheme has implications for synchronization between your filter routine and your interrupt service routine, you should avoid doing this unless your driver requires SoftDMA.
49<br><br>
50CAUTION: Called in primary interrupt context, if you need to disable interrupt to guard you registers against an unexpected call then it is better to use a straight IOInterruptEventSource and its secondary interrupt delivery mechanism.
51*/
52class IOFilterInterruptEventSource : public IOInterruptEventSource
53{
54 OSDeclareDefaultStructors(IOFilterInterruptEventSource)
55
56public:
57/*!
58 @typedef Filter
59 @discussion C Function pointer to a routine to call when an interrupt occurs.
60 @param owner Pointer to the owning/client instance.
61 @param sender Where is the interrupt comming from.
62 @result false if this interrupt can be ignored. */
63 typedef bool (*Filter)(OSObject *owner, IOFilterInterruptEventSource *sender);
64
65/*! @defined IOFilterInterruptAction
66 @discussion Backward compatibilty define for the old non-class scoped type definition. See $link IOFilterInterruptSource::Filter */
67#define IOFilterInterruptAction IOFilterInterruptEventSource::Filter
68
69#ifdef __BLOCKS__
70 typedef bool (^FilterBlock)(IOFilterInterruptEventSource *sender);
71#endif /* __BLOCKS__ */
72
73private:
74 // Hide the superclass initializers
75 virtual bool init(OSObject *inOwner,
76 IOInterruptEventSource::Action inAction = 0,
77 IOService *inProvider = 0,
78 int inIntIndex = 0) APPLE_KEXT_OVERRIDE;
79
80 static IOInterruptEventSource *
81 interruptEventSource(OSObject *inOwner,
82 IOInterruptEventSource::Action inAction = 0,
83 IOService *inProvider = 0,
84 int inIntIndex = 0);
85
86protected:
87/*! @var filterAction Filter callout */
88
89#if XNU_KERNEL_PRIVATE
90 union { Filter filterAction; FilterBlock filterActionBlock; };
91#else /* XNU_KERNEL_PRIVATE */
92 Filter filterAction;
93#endif /* !XNU_KERNEL_PRIVATE */
94
95/*! @struct ExpansionData
96 @discussion This structure will be used to expand the capablilties of the IOWorkLoop in the future.
97 */
98 struct ExpansionData { };
99
100/*! @var reserved
101 Reserved for future use. (Internal use only) */
102 APPLE_KEXT_WSHADOW_PUSH;
103 ExpansionData *reserved;
104 APPLE_KEXT_WSHADOW_POP;
105
106public:
107/*! @function filterInterruptEventSource
108 @abstract Factor method to create and initialise an IOFilterInterruptEventSource. See $link init.
109 @param owner Owner/client of this event source.
110 @param action 'C' Function to call when something happens.
111 @param filter 'C' Function to call when interrupt occurs.
112 @param provider Service that provides interrupts.
113 @param intIndex Defaults to 0.
114 @result a new event source if succesful, 0 otherwise. */
115 static IOFilterInterruptEventSource *
116 filterInterruptEventSource(OSObject *owner,
117 IOInterruptEventSource::Action action,
118 Filter filter,
119 IOService *provider,
120 int intIndex = 0);
121
122#ifdef __BLOCKS__
123/*! @function filterInterruptEventSource
124 @abstract Factor method to create and initialise an IOFilterInterruptEventSource. See $link init.
125 @param owner Owner/client of this event source.
126 @param provider Service that provides interrupts.
127 @param intIndex The index of the interrupt within the provider's interrupt sources.
128 @param action Block for the callout routine of this event source.
129 @param filter Block to invoke when HW interrupt occurs.
130 @result a new event source if succesful, 0 otherwise. */
131 static IOFilterInterruptEventSource *
132 filterInterruptEventSource(OSObject *owner,
133 IOService *provider,
134 int intIndex,
135 IOInterruptEventSource::ActionBlock action,
136 FilterBlock filter);
137#endif /* __BLOCKS__ */
138
139#if XNU_KERNEL_PRIVATE
140 enum
141 {
142 kFilterBlock = kSubClass0,
143 };
144#endif
145
146/*! @function init
147 @abstract Primary initialiser for the IOFilterInterruptEventSource class.
148 @param owner Owner/client of this event source.
149 @param action 'C' Function to call when something happens.
150 @param filter 'C' Function to call in primary interrupt context.
151 @param provider Service that provides interrupts.
152 @param intIndex Interrupt source within provider. Defaults to 0.
153 @result true if the inherited classes and this instance initialise
154successfully. */
155 virtual bool init(OSObject *owner,
156 IOInterruptEventSource::Action action,
157 Filter filter,
158 IOService *provider,
159 int intIndex = 0);
160
161 virtual void free( void ) APPLE_KEXT_OVERRIDE;
162
163/*! @function signalInterrupt
164 @abstract Cause the work loop to schedule the action.
165 @discussion Cause the work loop to schedule the interrupt action even if the filter routine returns 'false'. Note well the interrupting condition MUST be cleared from the hardware otherwise an infinite process interrupt loop will occur. Use this function when SoftDMA is desired. See $link IOFilterInterruptSource::Filter */
166 virtual void signalInterrupt();
167
168/*! @function getFilterAction
169 @abstract Get'ter for filterAction variable.
170 @result value of filterAction. */
171 virtual Filter getFilterAction() const;
172
173#ifdef __BLOCKS__
174/*! @function getFilterActionBlock
175 @abstract Get'ter for filterAction variable.
176 @result value of filterAction. */
177 FilterBlock getFilterActionBlock() const;
178#endif /* __BLOCKS__ */
179
180/*! @function normalInterruptOccurred
181 @abstract Override $link IOInterruptEventSource::normalInterruptOccured to make a filter callout. */
182 virtual void normalInterruptOccurred(void *self, IOService *prov, int ind) APPLE_KEXT_OVERRIDE;
183
184/*! @function disableInterruptOccurred
185 @abstract Override $link IOInterruptEventSource::disableInterruptOccurred to make a filter callout. */
186 virtual void disableInterruptOccurred(void *self, IOService *prov, int ind) APPLE_KEXT_OVERRIDE;
187
188private:
189 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 0);
190 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 1);
191 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 2);
192 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 3);
193 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 4);
194 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 5);
195 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 6);
196 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 7);
197};
198
199#endif /* !_IOKIT_IOFILTERINTERRUPTEVENTSOURCE_H */
200