1/* 2 * Copyright (c) 1998-2014 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 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* 29Copyright (c) 1998 Apple Computer, Inc. All rights reserved. 30 31HISTORY 32 1998-7-13 Godfrey van der Linden(gvdl) 33 Created. 34 1998-10-30 Godfrey van der Linden(gvdl) 35 Converted to C++ 36*/ 37 38#ifndef _IOKIT_IOINTERRUPTEVENTSOURCE_H 39#define _IOKIT_IOINTERRUPTEVENTSOURCE_H 40 41#include <IOKit/IOEventSource.h> 42 43class IOService; 44 45struct IOInterruptAccountingData; 46 47/*! @class IOInterruptEventSource : public IOEventSource 48 @abstract Event source for interrupt delivery to work-loop based drivers. 49 @discussion The IOInterruptEventSource is a generic object that delivers calls interrupt routines in it's client in a guaranteed single-threaded manner. IOInterruptEventSource is part of the IOKit $link IOWorkLoop infrastructure where the semantic that one and only one action method is executing within a work-loops event chain. 50<br><br> 51When the action method is called in the client member function will receive 2 arguments, (IOEventSource *) sender and (int) count, See $link IOInterruptEventSource::Action. Where sender will be reference to the interrupt that occurred and the count will be computed by the difference between the $link producerCount and $link consumerCount. This number may not be reliable as no attempt is made to adjust for around the world type problems but is provided for general information and statistic gathering. 52<br><br> 53In general a client will use the factory member function to create and initialise the event source and then add it to their work-loop. It is the work loop's responsiblity to maintain the new event source in it's event chain. See $link IOWorkLoop. 54<br><br> 55An interrupt event source attaches itself to the given provider's interrupt source at initialisation time. At this time it determines if it is connected to a level or edge triggered interrupt. If the interrupt is an level triggered interrupt the event source automatically disables the interrupt source at primary interrupt time and after it call's the client it automatically reenables the interrupt. This action is fairly expensive but it is 100% safe and defaults sensibly so that the driver writer does not have to implement type dependant interrupt routines. So to repeat, the driver writer does not have to be concerned by the actual underlying interrupt mechanism as the event source hides the complexity. 56<br><br> 57Saying this if the hardware is a multi-device card, for instance a 4 port NIC, where all of the devices are sharing one level triggered interrupt AND it is possible to determine each port's interrupt state non-destructively then the $link IOFilterInterruptEventSource would be a better choice. 58<br><br> 59Warning: All IOInterruptEventSources are created in the disabled state. If you want to actually schedule interrupt delivery do not forget to enable the source. 60*/ 61class IOInterruptEventSource : public IOEventSource 62{ 63 OSDeclareDefaultStructors(IOInterruptEventSource) 64 65public: 66/*! @typedef Action 67 @discussion 'C' pointer prototype of functions that are called in a single threaded context when an interrupt occurs. 68 @param owner Pointer to client instance. 69 @param sender Pointer to generation interrupt event source. 70 @param count Number of interrupts seen before delivery. */ 71 typedef void (*Action)(OSObject *, IOInterruptEventSource *, int count); 72 73/*! @defined IOInterruptEventAction 74 @discussion Backward compatibilty define for the old non-class scoped type definition. See $link IOInterruptEventSource::Action */ 75#define IOInterruptEventAction IOInterruptEventSource::Action 76 77protected: 78/*! @var provider IOService that provides interrupts for delivery. */ 79 IOService *provider; 80 81/*! @var intIndex */ 82 int intIndex; 83 84/*! @var producerCount 85 Current count of produced interrupts that have been received. */ 86 volatile unsigned int producerCount; 87 88/*! @var consumerCount 89 Current count of produced interrupts that the owner has been informed of. */ 90 unsigned int consumerCount; 91 92/*! @var autoDisable Do we need to automatically disable the interrupt source when we take an interrupt, i.e. we are level triggered. */ 93 bool autoDisable; 94 95/*! @var explicitDisable Has the user expicitly disabled this event source, if so then do not overide their request when returning from the callout */ 96 bool explicitDisable; 97 98/*! @struct ExpansionData 99 @discussion This structure will be used to expand the capablilties of the IOWorkLoop in the future. 100 */ 101 struct ExpansionData { 102 IOInterruptAccountingData * statistics; 103 }; 104 105/*! @var reserved 106 Reserved for future use. (Internal use only) */ 107 ExpansionData *reserved; 108 109/*! @function free 110 @abstract Sub-class implementation of free method, disconnects from the interrupt source. */ 111 virtual void free(); 112 113/*! @function checkForWork 114 @abstract Pure Virtual member function used by IOWorkLoop for issueing a client calls. 115 @discussion This function called when the work-loop is ready to check for any work to do and then to call out the owner/action. 116 @result Return true if this function needs to be called again before all its outstanding events have been processed. */ 117 virtual bool checkForWork(); 118 119/*! @function setWorkLoop 120 @abstract Sub-class implementation of setWorkLoop method. */ 121 virtual void setWorkLoop(IOWorkLoop *inWorkLoop); 122 123public: 124 125/*! @function interruptEventSource 126 @abstract Factory function for IOInterruptEventSources creation and initialisation. 127 @param owner Owning client of the new event source. 128 @param action 'C' Function to call when something happens. 129 @param provider IOService that represents the interrupt source. Defaults to 0. When no provider is defined the event source assumes that the client will in some manner call the interruptOccured method explicitly. This will start the ball rolling for safe delivery of asynchronous event's into the driver. 130 @param intIndex The index of the interrupt within the provider's interrupt sources. Defaults to 0, i.e. the first interrupt in the provider. 131 @result A new interrupt event source if successfully created and initialised, 0 otherwise. */ 132 static IOInterruptEventSource * 133 interruptEventSource(OSObject *owner, 134 Action action, 135 IOService *provider = 0, 136 int intIndex = 0); 137 138/*! @function init 139 @abstract Primary initialiser for the IOInterruptEventSource class. 140 @param owner Owning client of the new event source. 141 @param action 'C' Function to call when something happens. 142 @param provider IOService that represents the interrupt source. Defaults to 0. When no provider is defined the event source assumes that the client will in some manner call the interruptOccured method explicitly. This will start the ball rolling for safe delivery of asynchronous event's into the driver. 143 @param intIndex The index of the interrupt within the provider's interrupt sources. Defaults to 0, i.e. the first interrupt in the provider. 144 @result true if the inherited classes and this instance initialise 145successfully. */ 146 virtual bool init(OSObject *owner, 147 Action action, 148 IOService *provider = 0, 149 int intIndex = 0); 150 151/*! @function enable 152 @abstract Enable event source. 153 @discussion A subclass implementation is expected to respect the enabled 154state when checkForWork is called. Calling this function will cause the 155work-loop to be signalled so that a checkForWork is performed. */ 156 virtual void enable(); 157 158/*! @function disable 159 @abstract Disable event source. 160 @discussion A subclass implementation is expected to respect the enabled 161state when checkForWork is called. */ 162 virtual void disable(); 163 164/*! @function getProvider 165 @abstract Get'ter for $link provider variable. 166 @result value of provider. */ 167 virtual const IOService *getProvider() const; 168 169/*! @function getIntIndex 170 @abstract Get'ter for $link intIndex interrupt index variable. 171 @result value of intIndex. */ 172 virtual int getIntIndex() const; 173 174/*! @function getAutoDisable 175 @abstract Get'ter for $link autoDisable variable. 176 @result value of autoDisable. */ 177 virtual bool getAutoDisable() const; 178 179/*! @function interruptOccurred 180 @abstract Functions that get called by the interrupt controller. See $link IOService::registerInterrupt 181 @param nub Where did the interrupt originate from 182 @param ind What is this interrupts index within 'nub'. */ 183 virtual void interruptOccurred(void *, IOService *nub, int ind); 184 185/*! @function normalInterruptOccurred 186 @abstract Functions that get called by the interrupt controller.See $link IOService::registerInterrupt 187 @param nub Where did the interrupt originate from 188 @param ind What is this interrupts index within 'nub'. */ 189 virtual void normalInterruptOccurred(void *, IOService *nub, int ind); 190 191/*! @function disableInterruptOccurred 192 @abstract Functions that get called by the interrupt controller.See $link IOService::registerInterrupt 193 @param nub Where did the interrupt originate from 194 @param ind What is this interrupts index within 'nub'. */ 195 virtual void disableInterruptOccurred(void *, IOService *nub, int ind); 196 197/*! @function warmCPU 198 @abstract Tries to reduce latency for an interrupt which will be received near a specified time. 199 @discussion Warms up a CPU in advance of an interrupt so that the interrupt may be serviced with predictable latency. 200 The warm-up is not periodic; callers should call warmCPU once in advance of each interrupt. It is recommended that 201 requests be issues in serial (i.e. each after the target for the previous call has elapsed), as there is a systemwide 202 cap on the number of outstanding requests. This routine may be disruptive to the system if used with very small intervals 203 between requests; it should be used only in cases where interrupt latency is absolutely critical, and tens or hundreds of 204 milliseconds between targets is the expected time scale. NOTE: it is not safe to call this method with interrupts disabled. 205 @param abstime Time at which interrupt is expected. */ 206 IOReturn warmCPU(uint64_t abstime); 207 208private: 209 IOReturn registerInterruptHandler(IOService *inProvider, int inIntIndex); 210 void unregisterInterruptHandler(IOService *inProvider, int inIntIndex); 211 212private: 213 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 0); 214 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 1); 215 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 2); 216 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 3); 217 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 4); 218 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 5); 219 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 6); 220 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 7); 221}; 222 223#endif /* !_IOKIT_IOINTERRUPTEVENTSOURCE_H */ 224