sys/sys/ccbque.h

   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: 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 1.7 2005/06/03 17:14:51 dillon Exp $
  32  */
  33 /*
  34  * Common command control queue funcs.
  35  * Written by N. Honda.
  36  */
  37
  38 #ifndef _CCBQUE_H_
  39 #define _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(count)                                                \
  66         int count;                                                      \
  67 {                                                                       \
  68         if (CCBTYPE##que.maxccb == 0)                                   \
  69                 TAILQ_INIT(&CCBTYPE##que.CCBTYPE##tab);                 \
  70         CCBTYPE##que.maxccb += count;                                   \
  71 }                                                                       \
  72                                                                         \
  73 struct CCBTYPE *                                                        \
  74 DEV##_get_ccb()                                                         \
  75 {                                                                       \
  76         struct CCBTYPE *cb;                                             \
  77                                                                         \
  78         crit_enter();                                                   \
  79                                                                         \
  80         if (CCBTYPE##que.count < CCBTYPE##que.maxccb)                   \
  81         {                                                               \
  82                 CCBTYPE##que.count ++;                                  \
  83                 cb = TAILQ_FIRST(&CCBTYPE##que.CCBTYPE##tab);           \
  84                 if (cb != NULL)                                         \
  85                 {                                                       \
  86                         TAILQ_REMOVE(&CCBTYPE##que.CCBTYPE##tab, cb, CHAIN);\
  87                         goto out;                                       \
  88                 }                                                       \
  89                 else                                                    \
  90                 {                                                       \
  91                         cb = malloc(sizeof(*cb), M_DEVBUF, M_INTWAIT);  \
  92                         if (cb != NULL)                                 \
  93                         {                                               \
  94                                 bzero(cb, sizeof(*cb));                 \
  95                                 goto out;                               \
  96                         }                                               \
  97                 }                                                       \
  98                 CCBTYPE##que.count --;                                  \
  99         }                                                               \
 100                                                                         \
 101         cb = NULL;                                                      \
 102                                                                         \
 103 out:                                                                    \
 104         crit_exit();                                                    \
 105         return cb;                                                      \
 106 }                                                                       \
 107                                                                         \
 108 void                                                                    \
 109 DEV##_free_ccb(cb)                                                      \
 110         struct CCBTYPE *cb;                                     \
 111 {                                                                       \
 112         crit_enter();                                                   \
 113                                                                         \
 114         TAILQ_INSERT_TAIL(&CCBTYPE##que.CCBTYPE##tab, cb, CHAIN);       \
 115         CCBTYPE##que.count --;                                          \
 116                                                                         \
 117         if (CCBTYPE##que.flags & CCB_MWANTED)                           \
 118         {                                                               \
 119                 CCBTYPE##que.flags &= ~CCB_MWANTED;                     \
 120                 wakeup ((caddr_t) &CCBTYPE##que.count);                 \
 121         }                                                               \
 122         crit_exit();                                                    \
 123 }
 124 #endif  /* !_CCBQUE_H_ */