1 /* 2 * Copyright (c) 1998-2000 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 /* 29 Copyright (c) 1998 Apple Computer, Inc. All rights reserved. 30 31 HISTORY 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 43 class IOService; 44 45 /*! @class IOInterruptEventSource : public IOEventSource 46 @abstract Event source for interrupt delivery to work-loop based drivers. 47 @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. 48 <br><br> 49 When 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. 50 <br><br> 51 In 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. 52 <br><br> 53 An 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. 54 <br><br> 55 Saying 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. 56 <br><br> 57 Warning: All IOInterruptEventSources are created in the disabled state. If you want to actually schedule interrupt delivery do not forget to enable the source. 58 */ 59 class IOInterruptEventSource : public IOEventSource 60 { 61 OSDeclareDefaultStructors(IOInterruptEventSource) 62 63 public: 64 /*! @typedef Action 65 @discussion 'C' pointer prototype of functions that are called in a single threaded context when an interrupt occurs. 66 @param owner Pointer to client instance. 67 @param sender Pointer to generation interrupt event source. 68 @param count Number of interrupts seen before delivery. */ 69 typedef void (*Action)(OSObject *, IOInterruptEventSource *, int count); 70 71 /*! @defined IOInterruptEventAction 72 @discussion Backward compatibilty define for the old non-class scoped type definition. See $link IOInterruptEventSource::Action */ 73 #define IOInterruptEventAction IOInterruptEventSource::Action 74 75 protected: 76 /*! @var provider IOService that provides interrupts for delivery. */ 77 IOService *provider; 78 79 /*! @var intIndex */ 80 int intIndex; 81 82 /*! @var producerCount 83 Current count of produced interrupts that have been received. */ 84 volatile unsigned int producerCount; 85 86 /*! @var consumerCount 87 Current count of produced interrupts that the owner has been informed of. */ 88 unsigned int consumerCount; 89 90 /*! @var autoDisable Do we need to automatically disable the interrupt source when we take an interrupt, i.e. we are level triggered. */ 91 bool autoDisable; 92 93 /*! @var explicitDisable Has the user expicitly disabled this event source, if so then do not overide their request when returning from the callout */ 94 bool explicitDisable; 95 96 /*! @struct ExpansionData 97 @discussion This structure will be used to expand the capablilties of the IOWorkLoop in the future. 98 */ 99 struct ExpansionData { }; 100 101 /*! @var reserved 102 Reserved for future use. (Internal use only) */ 103 ExpansionData *reserved; 104 105 /*! @function free 106 @abstract Sub-class implementation of free method, disconnects from the interrupt source. */ 107 virtual void free(); 108 109 /*! @function checkForWork 110 @abstract Pure Virtual member function used by IOWorkLoop for issueing a client calls. 111 @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. 112 @result Return true if this function needs to be called again before all its outstanding events have been processed. */ 113 virtual bool checkForWork(); 114 115 /*! @function setWorkLoop 116 @abstract Sub-class implementation of setWorkLoop method. */ 117 virtual void setWorkLoop(IOWorkLoop *inWorkLoop); 118 119 public: 120 121 /*! @function interruptEventSource 122 @abstract Factory function for IOInterruptEventSources creation and initialisation. 123 @param owner Owning client of the new event source. 124 @param action 'C' Function to call when something happens. 125 @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. 126 @param intIndex The index of the interrupt within the provider's interrupt sources. Defaults to 0, i.e. the first interrupt in the provider. 127 @result A new interrupt event source if successfully created and initialised, 0 otherwise. */ 128 static IOInterruptEventSource * 129 interruptEventSource(OSObject *owner, 130 Action action, 131 IOService *provider = 0, 132 int intIndex = 0); 133 134 /*! @function init 135 @abstract Primary initialiser for the IOInterruptEventSource class. 136 @param owner Owning client of the new event source. 137 @param action 'C' Function to call when something happens. 138 @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. 139 @param intIndex The index of the interrupt within the provider's interrupt sources. Defaults to 0, i.e. the first interrupt in the provider. 140 @result true if the inherited classes and this instance initialise 141 successfully. */ 142 virtual bool init(OSObject *owner, 143 Action action, 144 IOService *provider = 0, 145 int intIndex = 0); 146 147 /*! @function enable 148 @abstract Enable event source. 149 @discussion A subclass implementation is expected to respect the enabled 150 state when checkForWork is called. Calling this function will cause the 151 work-loop to be signalled so that a checkForWork is performed. */ 152 virtual void enable(); 153 154 /*! @function disable 155 @abstract Disable event source. 156 @discussion A subclass implementation is expected to respect the enabled 157 state when checkForWork is called. */ 158 virtual void disable(); 159 160 /*! @function getProvider 161 @abstract Get'ter for $link provider variable. 162 @result value of provider. */ 163 virtual const IOService *getProvider() const; 164 165 /*! @function getIntIndex 166 @abstract Get'ter for $link intIndex interrupt index variable. 167 @result value of intIndex. */ 168 virtual int getIntIndex() const; 169 170 /*! @function getAutoDisable 171 @abstract Get'ter for $link autoDisable variable. 172 @result value of autoDisable. */ 173 virtual bool getAutoDisable() const; 174 175 /*! @function interruptOccurred 176 @abstract Functions that get called by the interrupt controller. See $link IOService::registerInterrupt 177 @param nub Where did the interrupt originate from 178 @param ind What is this interrupts index within 'nub'. */ 179 virtual void interruptOccurred(void *, IOService *nub, int ind); 180 181 /*! @function normalInterruptOccurred 182 @abstract Functions that get called by the interrupt controller.See $link IOService::registerInterrupt 183 @param nub Where did the interrupt originate from 184 @param ind What is this interrupts index within 'nub'. */ 185 virtual void normalInterruptOccurred(void *, IOService *nub, int ind); 186 187 /*! @function disableInterruptOccurred 188 @abstract Functions that get called by the interrupt controller.See $link IOService::registerInterrupt 189 @param nub Where did the interrupt originate from 190 @param ind What is this interrupts index within 'nub'. */ 191 virtual void disableInterruptOccurred(void *, IOService *nub, int ind); 192 193 /*! @function warmCPU 194 @abstract Tries to reduce latency for an interrupt which will be received near a specified time. 195 @discussion Warms up a CPU in advance of an interrupt so that the interrupt may be serviced with predictable latency. 196 The warm-up is not periodic; callers should call warmCPU once in advance of each interrupt. It is recommended that 197 requests be issues in serial (i.e. each after the target for the previous call has elapsed), as there is a systemwide 198 cap on the number of outstanding requests. This routine may be disruptive to the system if used with very small intervals 199 between requests; it should be used only in cases where interrupt latency is absolutely critical, and tens or hundreds of 200 milliseconds between targets is the expected time scale. NOTE: it is not safe to call this method with interrupts disabled. 201 @param abstime Time at which interrupt is expected. */ 202 IOReturn warmCPU(uint64_t abstime); 203 204 private: 205 IOReturn registerInterruptHandler(IOService *inProvider, int inIntIndex); 206 207 private: 208 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 0); 209 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 1); 210 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 2); 211 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 3); 212 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 4); 213 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 5); 214 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 6); 215 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 7); 216 }; 217 218 #endif /* !_IOKIT_IOINTERRUPTEVENTSOURCE_H */ 219