sys/sys/ccbque.h

   1 /*
   2  * [NetBSD for NEC PC98 series]
   3  *  Copyright (c) 1994, 1995, 1996 NetBSD/pc98 porting staff.
   4  *  All rights reserved.
   5  *
   6  *  Redistribution and use in source and binary forms, with or without
   7  *  modification, are permitted provided that the following conditions
   8  *  are met:
   9  *  1. Redistributions of source code must retain the above copyright
  10  *     notice, this list of conditions and the following disclaimer.
  11  *  2. Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  *  3. The name of the author may not be used to endorse or promote products
  15  *     derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  26  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27  * POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  * $NetBSD$
  30  * $FreeBSD: src/sys/i386/isa/ccbque.h,v 1.3.6.2 2000/10/21 07:44:24 nyan Exp $
  31  * $DragonFly: src/sys/sys/ccbque.h,v 1.11 2008/01/05 14:02:41 swildner Exp $
  32  */
  33 /*
  34  * Common command control queue funcs.
  35  * Written by N. Honda.
  36  */
  37
  38 #ifndef _SYS_CCBQUE_H_
  39 #define _SYS_CCBQUE_H_
  40
  41 #define CCB_MWANTED 0x01
  42
  43 /* (I)  structure and prototype */
  44 #define GENERIC_CCB_ASSERT(DEV, CCBTYPE)                                \
  45 TAILQ_HEAD(CCBTYPE##tab, CCBTYPE);                                      \
  46 struct CCBTYPE##que {                                                   \
  47         struct CCBTYPE##tab CCBTYPE##tab;                               \
  48         int count;                                                      \
  49         int maxccb;                                                     \
  50         u_int flags;                                                    \
  51 };                                                                      \
  52                                                                         \
  53 void DEV##_init_ccbque (int);                                   \
  54 struct CCBTYPE *DEV##_get_ccb (void);                           \
  55 void DEV##_free_ccb (struct CCBTYPE *);
  56
  57 /* (II)  static allocated memory */
  58 #define GENERIC_CCB_STATIC_ALLOC(DEV, CCBTYPE)                          \
  59 static struct CCBTYPE##que CCBTYPE##que;
  60
  61 /* (III)  functions */
  62 #define GENERIC_CCB(DEV, CCBTYPE, CHAIN)                                \
  63                                                                         \
  64 void                                                                    \
  65 DEV##_init_ccbque(int count)                                            \
  66 {                                                                       \
  67         if (CCBTYPE##que.maxccb == 0)                                   \
  68                 TAILQ_INIT(&CCBTYPE##que.CCBTYPE##tab);                 \
  69         CCBTYPE##que.maxccb += count;                                   \
  70 }                                                                       \
  71                                                                         \
  72 struct CCBTYPE *                                                        \
  73 DEV##_get_ccb(void)                                                             \
  74 {                                                                       \
  75         struct CCBTYPE *cb;                                             \
  76                                                                         \
  77         crit_enter();                                                   \
  78                                                                         \
  79         if (CCBTYPE##que.count < CCBTYPE##que.maxccb)                   \
  80         {                                                               \
  81                 CCBTYPE##que.count ++;                                  \
  82                 cb = TAILQ_FIRST(&CCBTYPE##que.CCBTYPE##tab);           \
  83                 if (cb != NULL)                                         \
  84                 {                                                       \
  85                         TAILQ_REMOVE(&CCBTYPE##que.CCBTYPE##tab, cb, CHAIN);\
  86                         goto out;                                       \
  87                 }                                                       \
  88                 else                                                    \
  89                 {                                                       \
  90                         cb = kmalloc(sizeof(*cb), M_DEVBUF, M_INTWAIT|M_ZERO);\
  91                         if (cb != NULL)                                 \
  92                                 goto out;                               \
  93                 }                                                       \
  94                 CCBTYPE##que.count --;                                  \
  95         }                                                               \
  96                                                                         \
  97         cb = NULL;                                                      \
  98                                                                         \
  99 out:                                                                    \
 100         crit_exit();                                                    \
 101         return cb;                                                      \
 102 }                                                                       \
 103                                                                         \
 104 void                                                                    \
 105 DEV##_free_ccb(struct CCBTYPE *cb)                                                      \
 106 {                                                                       \
 107         crit_enter();                                                   \
 108                                                                         \
 109         TAILQ_INSERT_TAIL(&CCBTYPE##que.CCBTYPE##tab, cb, CHAIN);       \
 110         CCBTYPE##que.count --;                                          \
 111                                                                         \
 112         if (CCBTYPE##que.flags & CCB_MWANTED)                           \
 113         {                                                               \
 114                 CCBTYPE##que.flags &= ~CCB_MWANTED;                     \
 115                 wakeup ((caddr_t) &CCBTYPE##que.count);                 \
 116         }                                                               \
 117         crit_exit();                                                    \
 118 }
 119 #endif  /* !_SYS_CCBQUE_H_ */