xref: /xnu-10002.81.5/iokit/IOKit/IOCommand.h (revision 5e3eaea39dcf651e66cb99ba7d70e32cc4a99587)
1*5e3eaea3SApple OSS Distributions /*
2*5e3eaea3SApple OSS Distributions  * Copyright (c) 2019 Apple Inc. All rights reserved.
3*5e3eaea3SApple OSS Distributions  *
4*5e3eaea3SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*5e3eaea3SApple OSS Distributions  *
6*5e3eaea3SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*5e3eaea3SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*5e3eaea3SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*5e3eaea3SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*5e3eaea3SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*5e3eaea3SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*5e3eaea3SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
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14*5e3eaea3SApple OSS Distributions  *
15*5e3eaea3SApple OSS Distributions  * Please obtain a copy of the License at
16*5e3eaea3SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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19*5e3eaea3SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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27*5e3eaea3SApple OSS Distributions  */
28*5e3eaea3SApple OSS Distributions 
29*5e3eaea3SApple OSS Distributions /*
30*5e3eaea3SApple OSS Distributions  *
31*5e3eaea3SApple OSS Distributions  *	Copyright (c) 2000 Apple Computer, Inc.  All rights reserved.
32*5e3eaea3SApple OSS Distributions  *
33*5e3eaea3SApple OSS Distributions  *	HISTORY
34*5e3eaea3SApple OSS Distributions  *
35*5e3eaea3SApple OSS Distributions  *	2001-01-18 gvdl	Made the primary queue pointer public, to be used when
36*5e3eaea3SApple OSS Distributions  *			Ownership is clear.
37*5e3eaea3SApple OSS Distributions  *	11/13/2000 CJS	Created IOCommand class and implementation
38*5e3eaea3SApple OSS Distributions  *
39*5e3eaea3SApple OSS Distributions  */
40*5e3eaea3SApple OSS Distributions 
41*5e3eaea3SApple OSS Distributions /*!
42*5e3eaea3SApple OSS Distributions  * @header IOCommand
43*5e3eaea3SApple OSS Distributions  * @abstract
44*5e3eaea3SApple OSS Distributions  * This header contains the IOCommand class definition.
45*5e3eaea3SApple OSS Distributions  */
46*5e3eaea3SApple OSS Distributions 
47*5e3eaea3SApple OSS Distributions #ifndef _IOKIT_IO_COMMAND_H_
48*5e3eaea3SApple OSS Distributions #define _IOKIT_IO_COMMAND_H_
49*5e3eaea3SApple OSS Distributions 
50*5e3eaea3SApple OSS Distributions /*
51*5e3eaea3SApple OSS Distributions  * Kernel
52*5e3eaea3SApple OSS Distributions  */
53*5e3eaea3SApple OSS Distributions 
54*5e3eaea3SApple OSS Distributions #if defined(KERNEL) && defined(__cplusplus)
55*5e3eaea3SApple OSS Distributions 
56*5e3eaea3SApple OSS Distributions #include <kern/queue.h>
57*5e3eaea3SApple OSS Distributions #include <libkern/c++/OSObject.h>
58*5e3eaea3SApple OSS Distributions 
59*5e3eaea3SApple OSS Distributions /*!
60*5e3eaea3SApple OSS Distributions  * @class IOCommand
61*5e3eaea3SApple OSS Distributions  * @abstract
62*5e3eaea3SApple OSS Distributions  * This class is an abstract class which represents an I/O command.
63*5e3eaea3SApple OSS Distributions  * @discussion
64*5e3eaea3SApple OSS Distributions  * This class is an abstract class which represents an I/O command passed
65*5e3eaea3SApple OSS Distributions  * from a device driver to a controller. All controller commands (e.g. IOATACommand)
66*5e3eaea3SApple OSS Distributions  * should inherit from this class.
67*5e3eaea3SApple OSS Distributions  */
68*5e3eaea3SApple OSS Distributions 
69*5e3eaea3SApple OSS Distributions class IOCommand : public OSObject
70*5e3eaea3SApple OSS Distributions {
71*5e3eaea3SApple OSS Distributions 	OSDeclareDefaultStructors(IOCommand);
72*5e3eaea3SApple OSS Distributions 
73*5e3eaea3SApple OSS Distributions public:
74*5e3eaea3SApple OSS Distributions 	virtual bool init(void) APPLE_KEXT_OVERRIDE;
75*5e3eaea3SApple OSS Distributions 
76*5e3eaea3SApple OSS Distributions /*! @var fCommandChain
77*5e3eaea3SApple OSS Distributions  *   This variable is used by the current 'owner' to queue the command.  During the life cycle of a command it moves through a series of queues.  This is the queue pointer for it.  Only valid while 'ownership' is clear.  For instance a IOCommandPool uses this pointer to maintain its list of free commands.  May be manipulated using the kern/queue.h macros */
78*5e3eaea3SApple OSS Distributions 	queue_chain_t fCommandChain;    /* used to queue commands */
79*5e3eaea3SApple OSS Distributions };
80*5e3eaea3SApple OSS Distributions 
81*5e3eaea3SApple OSS Distributions #endif /* defined(KERNEL) && defined(__cplusplus) */
82*5e3eaea3SApple OSS Distributions 
83*5e3eaea3SApple OSS Distributions #endif  /* _IOKIT_IO_COMMAND_H_ */
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