sys/bus/cam/cam_queue.h

   1 /*
   2  * CAM request queue management definitions.
   3  *
   4  * Copyright (c) 1997 Justin T. Gibbs.
   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  *    without modification, immediately at the beginning of the file.
  13  * 2. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $FreeBSD: src/sys/cam/cam_queue.h,v 1.6 1999/12/29 04:54:26 peter Exp $
  29  * $DragonFly: src/sys/bus/cam/cam_queue.h,v 1.3 2004/03/15 01:10:30 dillon Exp $
  30  */
  31
  32 #ifndef _CAM_CAM_QUEUE_H
  33 #define _CAM_CAM_QUEUE_H 1
  34
  35 #ifdef _KERNEL
  36
  37 #include <sys/queue.h>
  38
  39 /*
  40  * This structure implements a heap based priority queue.  The queue
  41  * assumes that the objects stored in it begin with a cam_qentry
  42  * structure holding the priority information used to sort the objects.
  43  * This structure is opaque to clients (outside of the XPT layer) to allow
  44  * the implementation to change without affecting them.
  45  */
  46 struct camq {
  47         cam_pinfo **queue_array;
  48         int        array_size;
  49         int        entries;
  50         u_int32_t  generation;
  51         u_int32_t  qfrozen_cnt;
  52 };
  53
  54 TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr);
  55 LIST_HEAD(ccb_hdr_list, ccb_hdr);
  56 SLIST_HEAD(ccb_hdr_slist, ccb_hdr);
  57
  58 struct cam_ccbq {
  59         struct  camq queue;
  60         int     devq_openings;
  61         int     dev_openings;
  62         int     dev_active;
  63         int     held;
  64         struct  ccb_hdr_tailq active_ccbs;
  65 };
  66
  67 struct cam_ed;
  68
  69 struct cam_devq {
  70         struct  camq alloc_queue;
  71         struct  camq send_queue;
  72         struct  cam_ed *active_dev;
  73         int     alloc_openings;
  74         int     alloc_active;
  75         int     send_openings;
  76         int     send_active;
  77         int     refcount;
  78         int     max_openings;
  79 };
  80
  81
  82 struct cam_devq *cam_devq_alloc(int devices, int openings);
  83
  84 int              cam_devq_init(struct cam_devq *devq, int devices,
  85                                int openings);
  86 void             cam_devq_reference(struct cam_devq *devq);
  87 void             cam_devq_release(struct cam_devq *devq);
  88 u_int32_t        cam_devq_resize(struct cam_devq *camq, int openings);
  89 void             cam_devq_set_openings(struct cam_devq *devq, int openings);
  90
  91
  92 /*
  93  * Allocate a cam_ccb_queue structure and initialize it.
  94  */
  95 struct cam_ccbq *cam_ccbq_alloc(int openings);
  96
  97 u_int32_t       cam_ccbq_resize(struct cam_ccbq *ccbq, int devices);
  98
  99 int             cam_ccbq_init(struct cam_ccbq *ccbq, int openings);
 100
 101 void            cam_ccbq_free(struct cam_ccbq *ccbq);
 102
 103 void            cam_ccbq_fini(struct cam_ccbq *ccbq);
 104
 105 /*
 106  * Allocate and initialize a cam_queue structure.
 107  */
 108 struct camq     *camq_alloc(int size);
 109
 110 /*
 111  * Resize a cam queue
 112  */
 113 u_int32_t       camq_resize(struct camq *queue, int new_size);
 114
 115 /*
 116  * Initialize a camq structure.  Return 0 on success, 1 on failure.
 117  */
 118 int             camq_init(struct camq *camq, int size);
 119
 120 /*
 121  * Free a cam_queue structure.  This should only be called if a controller
 122  * driver failes somehow during its attach routine or is unloaded and has
 123  * obtained a cam_queue structure.
 124  */
 125 void            camq_free(struct camq *queue);
 126
 127 /*
 128  * Finialize any internal storage or state of a cam_queue.
 129  */
 130 void            camq_fini(struct camq *queue);
 131
 132 /*
 133  * cam_queue_insert: Given a CAM queue with at least one open spot,
 134  * insert the new entry maintaining order.
 135  */
 136 void            camq_insert(struct camq *queue, cam_pinfo *new_entry);
 137
 138 /*
 139  * camq_remove: Remove and arbitrary entry from the queue maintaining
 140  * queue order.
 141  */
 142 cam_pinfo       *camq_remove(struct camq *queue, int index);
 143 #define CAMQ_HEAD 1     /* Head of queue index */
 144
 145 /* Index the first element in the heap */
 146 #define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD])
 147
 148 /*
 149  * camq_change_priority: Raise or lower the priority of an entry
 150  * maintaining queue order.
 151  */
 152 void            camq_change_priority(struct camq *queue, int index,
 153                                      u_int32_t new_priority);
 154
 155 static __inline int
 156 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq);
 157
 158 static __inline void
 159 cam_ccbq_take_opening(struct cam_ccbq *ccbq);
 160
 161 static __inline void
 162 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb);
 163
 164 static __inline void
 165 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb);
 166
 167 static __inline union ccb *
 168 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index);
 169
 170 static __inline void
 171 cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb);
 172
 173 static __inline void
 174 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb);
 175
 176 static __inline void
 177 cam_ccbq_release_opening(struct cam_ccbq *ccbq);
 178
 179
 180 static __inline int
 181 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq)
 182 {
 183         return (ccbq->queue.entries);
 184 }
 185
 186 static __inline void
 187 cam_ccbq_take_opening(struct cam_ccbq *ccbq)
 188 {
 189         ccbq->devq_openings--;
 190         ccbq->held++;
 191 }
 192
 193 static __inline void
 194 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb)
 195 {
 196         ccbq->held--;
 197         camq_insert(&ccbq->queue, &new_ccb->ccb_h.pinfo);
 198 }
 199
 200 static __inline void
 201 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb)
 202 {
 203         camq_remove(&ccbq->queue, ccb->ccb_h.pinfo.index);
 204 }
 205
 206 static __inline union ccb *
 207 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index)
 208 {
 209         return((union ccb *)ccbq->queue.queue_array[index]);
 210 }
 211
 212 static __inline void
 213 cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb)
 214 {
 215
 216         TAILQ_INSERT_TAIL(&ccbq->active_ccbs,
 217                           &(send_ccb->ccb_h),
 218                           xpt_links.tqe);
 219         send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX;
 220         ccbq->dev_active++;
 221         ccbq->dev_openings--;
 222 }
 223
 224 static __inline void
 225 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb)
 226 {
 227         TAILQ_REMOVE(&ccbq->active_ccbs, &done_ccb->ccb_h,
 228                      xpt_links.tqe);
 229         ccbq->dev_active--;
 230         ccbq->dev_openings++;
 231         ccbq->held++;
 232 }
 233
 234 static __inline void
 235 cam_ccbq_release_opening(struct cam_ccbq *ccbq)
 236 {
 237         ccbq->held--;
 238         ccbq->devq_openings++;
 239 }
 240
 241 #endif /* _KERNEL */
 242 #endif  /* _CAM_CAM_QUEUE_H */