ccbque.h revision 28861 
1/*	$NetBSD$	*/
2/*
3 * [NetBSD for NEC PC98 series]
4 *  Copyright (c) 1994, 1995, 1996 NetBSD/pc98 porting staff.
5 *  All rights reserved.
6 *
7 *  Redistribution and use in source and binary forms, with or without
8 *  modification, are permitted provided that the following conditions
9 *  are met:
10 *  1. Redistributions of source code must retain the above copyright
11 *     notice, this list of conditions and the following disclaimer.
12 *  2. Redistributions in binary form must reproduce the above copyright
13 *     notice, this list of conditions and the following disclaimer in the
14 *     documentation and/or other materials provided with the distribution.
15 *  3. The name of the author may not be used to endorse or promote products
16 *     derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
22 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
27 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30/*
31 * Common command control queue funcs.
32 * Written by N. Honda.
33 */
34
35#ifndef	_CCBQUE_H_
36#define	_CCBQUE_H_
37
38#define	CCB_MWANTED 0x01
39#define	CCB_WOK(fl) (((fl) == 0) ? M_WAITOK : M_NOWAIT)
40
41/* (I)  structure and prototype */
42#define GENERIC_CCB_ASSERT(DEV, CCBTYPE)				\
43TAILQ_HEAD(CCBTYPE##tab, CCBTYPE);					\
44struct CCBTYPE##que {							\
45	struct CCBTYPE##tab CCBTYPE##tab;				\
46	int count;							\
47	int maxccb;							\
48	u_int flags;							\
49};									\
50									\
51void DEV##_init_ccbque __P((int));					\
52struct CCBTYPE *DEV##_get_ccb __P((int));				\
53void DEV##_free_ccb __P((register struct CCBTYPE *));
54
55/* (II)  static allocated memory */
56#define GENERIC_CCB_STATIC_ALLOC(DEV, CCBTYPE)				\
57static struct CCBTYPE##que CCBTYPE##que;
58
59/* (III)  functions */
60#define GENERIC_CCB(DEV, CCBTYPE, CHAIN)				\
61									\
62void									\
63DEV##_init_ccbque(count)						\
64	int count;							\
65{									\
66	if (CCBTYPE##que.maxccb == 0)					\
67		TAILQ_INIT(&CCBTYPE##que.CCBTYPE##tab)			\
68	CCBTYPE##que.maxccb += count;					\
69}									\
70									\
71struct CCBTYPE *							\
72DEV##_get_ccb(flags)							\
73	int flags;							\
74{									\
75	register struct CCBTYPE *cb;					\
76	int s = splbio();						\
77									\
78again:									\
79	if (CCBTYPE##que.count < CCBTYPE##que.maxccb)			\
80	{								\
81		CCBTYPE##que.count ++;					\
82		cb = CCBTYPE##que.CCBTYPE##tab.tqh_first;		\
83		if (cb != NULL)						\
84		{							\
85			TAILQ_REMOVE(&CCBTYPE##que.CCBTYPE##tab, cb, CHAIN)\
86			goto out;					\
87		}							\
88		else							\
89		{							\
90			cb = malloc(sizeof(*cb), M_DEVBUF, CCB_WOK(flags));\
91			if (cb != NULL)					\
92			{						\
93				bzero(cb, sizeof(*cb));			\
94				goto out;				\
95			}						\
96		}							\
97		CCBTYPE##que.count --;					\
98	}								\
99									\
100	if (flags == 0)							\
101	{ 								\
102		CCBTYPE##que.flags |= CCB_MWANTED;			\
103		tsleep((caddr_t) &CCBTYPE##que.count, PRIBIO, "ccbwait", 0);\
104		goto again;						\
105	}								\
106	cb = NULL;							\
107									\
108out:									\
109	splx(s);							\
110	return cb;							\
111}									\
112									\
113void									\
114DEV##_free_ccb(cb)							\
115	register struct CCBTYPE *cb;					\
116{									\
117	int s = splbio();						\
118									\
119	TAILQ_INSERT_TAIL(&CCBTYPE##que.CCBTYPE##tab, cb, CHAIN)	\
120	CCBTYPE##que.count --;						\
121									\
122	if (CCBTYPE##que.flags & CCB_MWANTED)				\
123	{								\
124		CCBTYPE##que.flags &= ~CCB_MWANTED;			\
125		wakeup ((caddr_t) &CCBTYPE##que.count);			\
126	}								\
127	splx(s);							\
128}
129#endif	/* !_CCBQUE_H_ */
130