xref: /illumos-gate/usr/src/uts/intel/sys/polled_io.h (revision 88f8b78a88cbdc6d8c1af5c3e54bc49d25095c98)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 1998-1999 by Sun Microsystems, Inc.
24  * All rights reserved.
25  */
26 
27 #ifndef _SYS_POLLED_IO_H
28 #define	_SYS_POLLED_IO_H
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #ifdef	__cplusplus
33 extern "C" {
34 #endif
35 
36 typedef struct polled_device {
37 	/*
38 	 * This lock is only used to lock writing from
39 	 * the fields on the structure.  The values in the
40 	 * structure can be read under obp, so the lock
41 	 * isn't valid then.
42 	 */
43 	kmutex_t	polled_device_lock;
44 
45 	/*
46 	 * When we switch over the console, this is the old value
47 	 * so that we can restore it later.
48 	 */
49 	uint64_t	polled_old_handle;
50 
51 	/*
52 	 * Pointer to registerd polled I/O callbacks.
53 	 */
54 	cons_polledio_t	*polled_io;
55 
56 } polled_device_t;
57 
58 _NOTE(MUTEX_PROTECTS_DATA(polled_device_t::polled_device_lock,
59 	polled_device_t))
60 
61 /*
62  * The lower layers did not find any characters.
63  */
64 #define	CIF_NO_CHARACTERS	((uint_t)-2)
65 
66 /*
67  * Every CIF has at least 3 arguments:  0 (name), 1 (in args), and 2 (out args).
68  */
69 #define	CIF_MIN_SIZE		3
70 
71 #define	CIF_NAME		0	/* name of function */
72 #define	CIF_NUMBER_IN_ARGS	1	/* number of arguments passed in */
73 #define	CIF_NUMBER_OUT_ARGS	2	/* number of arguments for return */
74 #define	CIF_BUFFER_ADDRESS	3	/* address to write data */
75 #define	CIF_BUFFER_LENGTH	4	/* length of BUFFER_ADDRESS */
76 #define	CIF_RETURN_VALUE	5	/* return status of operation */
77 
78 
79 /*
80  * This is the size of the structure that we are expecting to be passed
81  * in.  This is based on CIF_MIN_SIZE + address + length + value (see above)
82  */
83 #define	CIF_SIZE		6	/* size of cif structure */
84 
85 /*
86  * These are the types of polled I/O that this module handles.
87  */
88 typedef enum polled_io_console_type {
89 	POLLED_IO_CONSOLE_INPUT = 0,
90 	POLLED_IO_CONSOLE_OUTPUT = 1
91 } polled_io_console_type_t;
92 
93 /*
94  * Initialize the polled I/O kernel structures
95  */
96 void	polled_io_init(void);
97 
98 /*
99  * De-initialize the polled I/O kernel structures
100  */
101 void	polled_io_fini(void);
102 
103 /*
104  * Register a device to be used as a console for OBP.
105  */
106 int	polled_io_register_callbacks(cons_polledio_t *, int);
107 
108 /*
109  * Unregister a device to be used as a console for OBP.
110  */
111 int	polled_io_unregister_callbacks(cons_polledio_t *, int);
112 
113 #ifdef	__cplusplus
114 }
115 #endif
116 
117 #endif	/* _SYS_POLLED_IO_H */
118