ccbque.h revision 331722 
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 * $FreeBSD: stable/11/sys/i386/isa/ccbque.h 331722 2018-03-29 02:50:57Z eadler $
31 */
32/*
33 * Common command control queue funcs.
34 * Written by N. Honda.
35 */
36
37#ifndef	_CCBQUE_H_
38#define	_CCBQUE_H_
39
40#define	CCB_MWANTED 0x01
41
42/* (I)  structure and prototype */
43#define GENERIC_CCB_ASSERT(DEV, CCBTYPE)				\
44TAILQ_HEAD(CCBTYPE##tab, CCBTYPE);					\
45struct CCBTYPE##que {							\
46	struct CCBTYPE##tab CCBTYPE##tab;				\
47	int count;							\
48	int maxccb;							\
49	u_int flags;							\
50};									\
51									\
52void DEV##_init_ccbque(int);					\
53struct CCBTYPE *DEV##_get_ccb(void);				\
54void DEV##_free_ccb(struct CCBTYPE *);
55
56/* (II)  static allocated memory */
57#define GENERIC_CCB_STATIC_ALLOC(DEV, CCBTYPE)				\
58static struct CCBTYPE##que CCBTYPE##que;
59
60/* (III)  functions */
61#define GENERIC_CCB(DEV, CCBTYPE, CHAIN)				\
62									\
63void									\
64DEV##_init_ccbque(count)						\
65	int count;							\
66{									\
67	if (CCBTYPE##que.maxccb == 0)					\
68		TAILQ_INIT(&CCBTYPE##que.CCBTYPE##tab);			\
69	CCBTYPE##que.maxccb += count;					\
70}									\
71									\
72struct CCBTYPE *							\
73DEV##_get_ccb()								\
74{									\
75	struct CCBTYPE *cb;						\
76	int s = splcam();						\
77									\
78	if (CCBTYPE##que.count < CCBTYPE##que.maxccb)			\
79	{								\
80		CCBTYPE##que.count ++;					\
81		cb = TAILQ_FIRST(&(CCBTYPE##que.CCBTYPE##tab));		\
82		if (cb != NULL)						\
83		{							\
84			TAILQ_REMOVE(&CCBTYPE##que.CCBTYPE##tab, cb, CHAIN);\
85			goto out;					\
86		}							\
87		else							\
88		{							\
89			cb = malloc(sizeof(*cb), M_DEVBUF, M_NOWAIT);	\
90			if (cb != NULL)					\
91			{						\
92				bzero(cb, sizeof(*cb));			\
93				goto out;				\
94			}						\
95		}							\
96		CCBTYPE##que.count --;					\
97	}								\
98									\
99	cb = NULL;							\
100									\
101out:									\
102	splx(s);							\
103	return cb;							\
104}									\
105									\
106void									\
107DEV##_free_ccb(cb)							\
108	struct CCBTYPE *cb;						\
109{									\
110	int s = splcam();						\
111									\
112	TAILQ_INSERT_TAIL(&CCBTYPE##que.CCBTYPE##tab, cb, CHAIN);	\
113	CCBTYPE##que.count --;						\
114									\
115	if (CCBTYPE##que.flags & CCB_MWANTED)				\
116	{								\
117		CCBTYPE##que.flags &= ~CCB_MWANTED;			\
118		wakeup ((caddr_t) &CCBTYPE##que.count);			\
119	}								\
120	splx(s);							\
121}
122#endif	/* !_CCBQUE_H_ */
123