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 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) 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 42 class 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 */ 54 class IOFilterInterruptEventSource : public IOInterruptEventSource 55 { 56 OSDeclareDefaultStructors(IOFilterInterruptEventSource); 57 58 public: 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 75 private: 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 88 protected: 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; 107 108 public: 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; 188 189 private: 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