xref: /xnu-8019.80.24/iokit/DriverKit/IOInterruptDispatchSource.iig (revision a325d9c4a84054e40bbe985afedcb50ab80993ea)

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#ifndef _IOKIT_UIOINTERRUPTDISPATCHSOURCE_H
#define _IOKIT_UIOINTERRUPTDISPATCHSOURCE_H

#include <DriverKit/IODispatchQueue.iig>
#include <DriverKit/IOService.iig>

struct IOInterruptDispatchSourcePayload {
	uint64_t time;
	uint64_t count;
};

enum {
	kIOInterruptDispatchSourceTypeEdge  = 0x00000000,
	kIOInterruptDispatchSourceTypeLevel = 0x00000001
};

enum {
	kIOInterruptSourceIndexMask      = 0x0000FFFF,
	kIOInterruptSourceAbsoluteTime   = 0x00000000,
	kIOInterruptSourceContinuousTime = 0x00010000
};

/*!
 * @class IOInterruptDispatchSource
 *
 * @abstract
 * IOInterruptDispatchSource delivers interrupts to a handler block on a dispatch queue.
 *
 * @discussion
 * A driver can run code in response to an interrupt from a device, specified as an IOService
 * and index. The code runs at normal thread level, but is notified with the mach_absolute_time
 * the primary interrupt fired. For IOPCIDevices, only MSI interrupt sources are supported.
 */

class NATIVE KERNEL IOInterruptDispatchSource : public IODispatchSource
{
public:

    /*!
     * @brief       Create an IOInterruptDispatchSource for an interrupt by index from an IOService provider.
     * @param       provider The IOService object representing the HW device producing the interrupt.
     * @param       index Index for the interrupt, optionally or'ed with one of the following constants:
                    kIOInterruptSourceContinuousTime time values sent to the InterruptOccurred() method will be in mach_continuous_time() units.
     * @param       queue Target queue to run the handler block.
     * @param       source Created source with +1 retain count to be released by the caller.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */
	static kern_return_t
	Create(IOService * provider,
	    uint32_t index,
	    IODispatchQueue * queue,
	    IOInterruptDispatchSource ** source) LOCAL;

    /*!
     * @brief       Returns the type of interrupt used for a device supplying hardware interrupts, by index from an IOService provider.
     * @param       provider The IOService object representing the HW device producing the interrupt.
     * @param       index Index for the interrupt.
     * @param 		interruptType The interrupt type for the interrupt source will be stored here.
     *              kIOInterruptTypeEdge will be returned for edge-trigggered sources.
     *              kIOInterruptTypeLevel will be returned for level-trigggered sources.
     *              Other flags may be returned depending on the provider, for example PCI flags for messaged interrupts.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */

	static kern_return_t
	GetInterruptType(IOService * provider,
	    uint32_t index,
	    uint64_t * interruptType);

	virtual bool
	init() override;

	virtual void
	free() override;

    /*!
     * @brief       Set the handler block to run when the interupt fires.
     * @param       action OSAction instance specifying the callback method. The OSAction object will be retained
     *              until SetHandler is called again or the event source is cancelled.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */
	virtual kern_return_t
	    SetHandler(
		OSAction * action TYPE(InterruptOccurred)) LOCAL;

    /*!
     * @brief       Control the enable state of the interrupt source.
     * @param       enable Pass true to enable the source or false to disable.
     * @param       handler Optional block to be executed after the interrupt has been disabled and any pending
     *              interrupt handlers completed.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */
	virtual kern_return_t
	SetEnableWithCompletion(
		bool enable,
		IODispatchSourceCancelHandler handler) override LOCAL;

    /*!
     * @brief       Cancel all callbacks from the event source.
     * @discussion  After cancellation, the source can only be freed. It cannot be reactivated.
     * @param       handler Handler block to be invoked after any callbacks have completed.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */
	virtual kern_return_t
	Cancel(IODispatchSourceCancelHandler handler) override LOCAL;

private:
	virtual kern_return_t
	CheckForWork(bool synchronous) override LOCAL;

	virtual void
	InterruptOccurred(
		OSAction * action TARGET,
		uint64_t   count,
		uint64_t   time) REPLY LOCAL;
};

#endif /* ! _IOKIT_UIOINTERRUPTDISPATCHSOURCE_H */