1/*
2 * Copyright (c) 1998-2019 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
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27 */
28/*
29 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
30 *
31 * HISTORY
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 <libkern/c++/OSPtr.h>
39#include <IOKit/IOInterruptEventSource.h>
40#include <libkern/c++/OSPtr.h>
41
42class IOService;
43
44/*! @class IOFilterInterruptEventSource : public IOInterruptEventSource
45 * @abstract Filtering varient of the $link IOInterruptEventSource.
46 * @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.
47 * <br><br>
48 * 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.
49 * <br><br>
50 * If 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.
51 * <br><br>
52 * CAUTION: 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.
53 */
54class IOFilterInterruptEventSource : public IOInterruptEventSource
55{
56 OSDeclareDefaultStructors(IOFilterInterruptEventSource);
57
58public:
59/*!
60 * @typedef Filter
61 * @discussion C Function pointer to a routine to call when an interrupt occurs.
62 * @param owner Pointer to the owning/client instance.
63 * @param sender Where is the interrupt comming from.
64 * @result false if this interrupt can be ignored. */
65 typedef bool (*Filter)(OSObject *owner, IOFilterInterruptEventSource *sender);
66
67/*! @defined IOFilterInterruptAction
68 * @discussion Backward compatibilty define for the old non-class scoped type definition. See $link IOFilterInterruptSource::Filter */
69#define IOFilterInterruptAction IOFilterInterruptEventSource::Filter
70
71#ifdef __BLOCKS__
72 typedef bool (^FilterBlock)(IOFilterInterruptEventSource *sender);
73#endif /* __BLOCKS__ */
74
75private:
76// Hide the superclass initializers
77 virtual bool init(OSObject *inOwner,
78 IOInterruptEventSource::Action inAction = NULL,
79 IOService *inProvider = NULL,
80 int inIntIndex = 0) APPLE_KEXT_OVERRIDE;
81
82 static OSPtr<IOInterruptEventSource>
83 interruptEventSource(OSObject *inOwner,
84 IOInterruptEventSource::Action inAction = NULL,
85 IOService *inProvider = NULL,
86 int inIntIndex = 0);
87
88protected:
89/*! @var filterAction Filter callout */
90
91#if XNU_KERNEL_PRIVATE
92 union { Filter filterAction; FilterBlock filterActionBlock; };
93#else /* XNU_KERNEL_PRIVATE */
94 Filter filterAction;
95#endif /* !XNU_KERNEL_PRIVATE */
96
97/*! @struct ExpansionData
98 * @discussion This structure will be used to expand the capablilties of the IOWorkLoop in the future.
99 */
100 struct ExpansionData { };
101
102/*! @var reserved
103 * Reserved for future use. (Internal use only) */
104 APPLE_KEXT_WSHADOW_PUSH;
105 ExpansionData *reserved;
106 APPLE_KEXT_WSHADOW_POP;
107
108public:
109/*! @function filterInterruptEventSource
110 * @abstract Factor method to create and initialise an IOFilterInterruptEventSource. See $link init.
111 * @param owner Owner/client of this event source.
112 * @param action 'C' Function to call when something happens.
113 * @param filter 'C' Function to call when interrupt occurs.
114 * @param provider Service that provides interrupts.
115 * @param intIndex Defaults to 0.
116 * @result a new event source if succesful, 0 otherwise. */
117 static OSPtr<IOFilterInterruptEventSource>
118 filterInterruptEventSource(OSObject *owner,
119 IOInterruptEventSource::Action action,
120 Filter filter,
121 IOService *provider,
122 int intIndex = 0);
123
124#ifdef __BLOCKS__
125/*! @function filterInterruptEventSource
126 * @abstract Factor method to create and initialise an IOFilterInterruptEventSource. See $link init.
127 * @param owner Owner/client of this event source.
128 * @param provider Service that provides interrupts.
129 * @param intIndex The index of the interrupt within the provider's interrupt sources.
130 * @param action Block for the callout routine of this event source.
131 * @param filter Block to invoke when HW interrupt occurs.
132 * @result a new event source if succesful, 0 otherwise. */
133 static OSPtr<IOFilterInterruptEventSource>
134 filterInterruptEventSource(OSObject *owner,
135 IOService *provider,
136 int intIndex,
137 IOInterruptEventSource::ActionBlock action,
138 FilterBlock filter);
139#endif /* __BLOCKS__ */
140
141#if XNU_KERNEL_PRIVATE
142 enum{
143 kFilterBlock = kSubClass0,
144 };
145#endif
146
147/*! @function init
148 * @abstract Primary initialiser for the IOFilterInterruptEventSource class.
149 * @param owner Owner/client of this event source.
150 * @param action 'C' Function to call when something happens.
151 * @param filter 'C' Function to call in primary interrupt context.
152 * @param provider Service that provides interrupts.
153 * @param intIndex Interrupt source within provider. Defaults to 0.
154 * @result true if the inherited classes and this instance initialise
155 * successfully. */
156 virtual bool init(OSObject *owner,
157 IOInterruptEventSource::Action action,
158 Filter filter,
159 IOService *provider,
160 int intIndex = 0);
161
162 virtual void free( void ) APPLE_KEXT_OVERRIDE;
163
164/*! @function signalInterrupt
165 * @abstract Cause the work loop to schedule the action.
166 * @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 */
167 virtual void signalInterrupt();
168
169/*! @function getFilterAction
170 * @abstract Get'ter for filterAction variable.
171 * @result value of filterAction. */
172 virtual Filter getFilterAction() const;
173
174#ifdef __BLOCKS__
175/*! @function getFilterActionBlock
176 * @abstract Get'ter for filterAction variable.
177 * @result value of filterAction. */
178 FilterBlock getFilterActionBlock() const;
179#endif /* __BLOCKS__ */
180
181/*! @function normalInterruptOccurred
182 * @abstract Override $link IOInterruptEventSource::normalInterruptOccured to make a filter callout. */
183 virtual void normalInterruptOccurred(void *self, IOService *prov, int ind) APPLE_KEXT_OVERRIDE;
184
185/*! @function disableInterruptOccurred
186 * @abstract Override $link IOInterruptEventSource::disableInterruptOccurred to make a filter callout. */
187 virtual void disableInterruptOccurred(void *self, IOService *prov, int ind) APPLE_KEXT_OVERRIDE;
188
189private:
190 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 0);
191 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 1);
192 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 2);
193 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 3);
194 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 4);
195 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 5);
196 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 6);
197 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 7);
198};
199
200#endif /* !_IOKIT_IOFILTERINTERRUPTEVENTSOURCE_H */
201