target_firmware/wlan/queue.h

   1 /*
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
  30  * $FreeBSD: src/sys/sys/queue.h,v 1.58 2004/04/07 04:19:49 imp Exp $
  31  * $Id: //depot/sw/branches/fusion_usb/target_firmware/wlan/target/madwifi/include/sys/queue.h#1 $
  32  */
  33
  34 #ifndef _SYS_QUEUE_H_
  35 #define _SYS_QUEUE_H_
  36
  37 /*
  38  * This file defines four types of data structures: singly-linked lists,
  39  * singly-linked tail queues, lists and tail queues.
  40  *
  41  * A singly-linked list is headed by a single forward pointer. The elements
  42  * are singly linked for minimum space and pointer manipulation overhead at
  43  * the expense of O(n) removal for arbitrary elements. New elements can be
  44  * added to the list after an existing element or at the head of the list.
  45  * Elements being removed from the head of the list should use the explicit
  46  * macro for this purpose for optimum efficiency. A singly-linked list may
  47  * only be traversed in the forward direction.  Singly-linked lists are ideal
  48  * for applications with large datasets and few or no removals or for
  49  * implementing a LIFO queue.
  50  *
  51  * A singly-linked tail queue is headed by a pair of pointers, one to the
  52  * head of the list and the other to the tail of the list. The elements are
  53  * singly linked for minimum space and pointer manipulation overhead at the
  54  * expense of O(n) removal for arbitrary elements. New elements can be added
  55  * to the list after an existing element, at the head of the list, or at the
  56  * end of the list. Elements being removed from the head of the tail queue
  57  * should use the explicit macro for this purpose for optimum efficiency.
  58  * A singly-linked tail queue may only be traversed in the forward direction.
  59  * Singly-linked tail queues are ideal for applications with large datasets
  60  * and few or no removals or for implementing a FIFO queue.
  61  *
  62  * A list is headed by a single forward pointer (or an array of forward
  63  * pointers for a hash table header). The elements are doubly linked
  64  * so that an arbitrary element can be removed without a need to
  65  * traverse the list. New elements can be added to the list before
  66  * or after an existing element or at the head of the list. A list
  67  * may only be traversed in the forward direction.
  68  *
  69  * A tail queue is headed by a pair of pointers, one to the head of the
  70  * list and the other to the tail of the list. The elements are doubly
  71  * linked so that an arbitrary element can be removed without a need to
  72  * traverse the list. New elements can be added to the list before or
  73  * after an existing element, at the head of the list, or at the end of
  74  * the list. A tail queue may be traversed in either direction.
  75  *
  76  * For details on the use of these macros, see the queue(3) manual page.
  77  *
  78  *
  79  *                              SLIST   LIST    STAILQ  TAILQ
  80  * _HEAD                        +       +       +       +
  81  * _HEAD_INITIALIZER            +       +       +       +
  82  * _ENTRY                       +       +       +       +
  83  * _INIT                        +       +       +       +
  84  * _EMPTY                       +       +       +       +
  85  * _FIRST                       +       +       +       +
  86  * _NEXT                        +       +       +       +
  87  * _PREV                        -       -       -       +
  88  * _LAST                        -       -       +       +
  89  * _FOREACH                     +       +       +       +
  90  * _FOREACH_SAFE                +       +       +       +
  91  * _FOREACH_REVERSE             -       -       -       +
  92  * _FOREACH_REVERSE_SAFE        -       -       -       +
  93  * _INSERT_HEAD                 +       +       +       +
  94  * _INSERT_BEFORE               -       +       -       +
  95  * _INSERT_AFTER                +       +       +       +
  96  * _INSERT_TAIL                 -       -       +       +
  97  * _CONCAT                      -       -       +       +
  98  * _REMOVE_HEAD                 +       -       +       -
  99  * _REMOVE                      +       +       +       +
 100  *
 101  */
 102 #define QUEUE_MACRO_DEBUG 0
 103 #if QUEUE_MACRO_DEBUG
 104 /* Store the last 2 places the queue element or head was altered */
 105 struct qm_trace {
 106         char * lastfile;
 107         a_int32_t lastline;
 108         char * prevfile;
 109         a_int32_t prevline;
 110 };
 111
 112 #define TRACEBUF        struct qm_trace trace;
 113 #define TRASHIT(x)      do {(x) = (void *)-1;} while (0)
 114
 115 #define QMD_TRACE_HEAD(head) do {                                       \
 116         (head)->trace.prevline = (head)->trace.lastline;                \
 117         (head)->trace.prevfile = (head)->trace.lastfile;                \
 118         (head)->trace.lastline = __LINE__;                              \
 119         (head)->trace.lastfile = __FILE__;                              \
 120 } while (0)
 121
 122 #define QMD_TRACE_ELEM(elem) do {                                       \
 123         (elem)->trace.prevline = (elem)->trace.lastline;                \
 124         (elem)->trace.prevfile = (elem)->trace.lastfile;                \
 125         (elem)->trace.lastline = __LINE__;                              \
 126         (elem)->trace.lastfile = __FILE__;                              \
 127 } while (0)
 128
 129 #else
 130 #define QMD_TRACE_ELEM(elem)
 131 #define QMD_TRACE_HEAD(head)
 132 #define TRACEBUF
 133 #define TRASHIT(x)
 134 #endif  /* QUEUE_MACRO_DEBUG */
 135
 136 /*
 137  * Singly-linked List declarations.
 138  */
 139 #define SLIST_HEAD(name, type)                                          \
 140 struct name {                                                           \
 141         struct type *slh_first; /* first element */                     \
 142 }
 143
 144 #define SLIST_HEAD_INITIALIZER(head)                                    \
 145         { NULL }
 146
 147 #define SLIST_ENTRY(type)                                               \
 148 struct {                                                                \
 149         struct type *sle_next;  /* next element */                      \
 150 }
 151
 152 /*
 153  * Singly-linked List functions.
 154  */
 155 #define SLIST_EMPTY(head)       ((head)->slh_first == NULL)
 156
 157 #define SLIST_FIRST(head)       ((head)->slh_first)
 158
 159 #define SLIST_FOREACH(var, head, field)                                 \
 160         for ((var) = SLIST_FIRST((head));                               \
 161             (var);                                                      \
 162             (var) = SLIST_NEXT((var), field))
 163
 164 #define SLIST_FOREACH_SAFE(var, head, field, tvar)                      \
 165         for ((var) = SLIST_FIRST((head));                               \
 166             (var) && ((tvar) = SLIST_NEXT((var), field), 1);            \
 167             (var) = (tvar))
 168
 169 #define SLIST_FOREACH_PREVPTR(var, varp, head, field)                   \
 170         for ((varp) = &SLIST_FIRST((head));                             \
 171             ((var) = *(varp)) != NULL;                                  \
 172             (varp) = &SLIST_NEXT((var), field))
 173
 174 #define SLIST_INIT(head) do {                                           \
 175         SLIST_FIRST((head)) = NULL;                                     \
 176 } while (0)
 177
 178 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
 179         SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);       \
 180         SLIST_NEXT((slistelm), field) = (elm);                          \
 181 } while (0)
 182
 183 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
 184         SLIST_NEXT((elm), field) = SLIST_FIRST((head));                 \
 185         SLIST_FIRST((head)) = (elm);                                    \
 186 } while (0)
 187
 188 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
 189
 190 #define SLIST_REMOVE(head, elm, type, field) do {                       \
 191         if (SLIST_FIRST((head)) == (elm)) {                             \
 192                 SLIST_REMOVE_HEAD((head), field);                       \
 193         }                                                               \
 194         else {                                                          \
 195                 struct type *curelm = SLIST_FIRST((head));              \
 196                 while (SLIST_NEXT(curelm, field) != (elm))              \
 197                         curelm = SLIST_NEXT(curelm, field);             \
 198                 SLIST_NEXT(curelm, field) =                             \
 199                     SLIST_NEXT(SLIST_NEXT(curelm, field), field);       \
 200         }                                                               \
 201 } while (0)
 202
 203 #define SLIST_REMOVE_HEAD(head, field) do {                             \
 204         SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);   \
 205 } while (0)
 206
 207 /*
 208  * Singly-linked Tail queue declarations.
 209  */
 210 #define STAILQ_HEAD(name, type)                                         \
 211 struct name {                                                           \
 212         struct type *stqh_first;/* first element */                     \
 213         struct type **stqh_last;/* addr of last next element */         \
 214 }
 215
 216 #define STAILQ_HEAD_INITIALIZER(head)                                   \
 217         { NULL, &(head).stqh_first }
 218
 219 #define STAILQ_ENTRY(type)                                              \
 220 struct {                                                                \
 221         struct type *stqe_next; /* next element */                      \
 222 }
 223
 224 /*
 225  * Singly-linked Tail queue functions.
 226  */
 227 #define STAILQ_CONCAT(head1, head2) do {                                \
 228         if (!STAILQ_EMPTY((head2))) {                                   \
 229                 *(head1)->stqh_last = (head2)->stqh_first;              \
 230                 (head1)->stqh_last = (head2)->stqh_last;                \
 231                 STAILQ_INIT((head2));                                   \
 232         }                                                               \
 233 } while (0)
 234
 235 #define STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
 236
 237 #define STAILQ_FIRST(head)      ((head)->stqh_first)
 238
 239 #define STAILQ_FOREACH(var, head, field)                                \
 240         for((var) = STAILQ_FIRST((head));                               \
 241            (var);                                                       \
 242            (var) = STAILQ_NEXT((var), field))
 243
 244
 245 #define STAILQ_FOREACH_SAFE(var, head, field, tvar)                     \
 246         for ((var) = STAILQ_FIRST((head));                              \
 247             (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
 248             (var) = (tvar))
 249
 250 #define STAILQ_INIT(head) do {                                          \
 251         STAILQ_FIRST((head)) = NULL;                                    \
 252         (head)->stqh_last = &STAILQ_FIRST((head));                      \
 253 } while (0)
 254
 255 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
 256         if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
 257                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
 258         STAILQ_NEXT((tqelm), field) = (elm);                            \
 259 } while (0)
 260
 261 #define STAILQ_INSERT_HEAD(head, elm, field) do {                       \
 262         if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
 263                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
 264         STAILQ_FIRST((head)) = (elm);                                   \
 265 } while (0)
 266
 267 #define STAILQ_INSERT_TAIL(head, elm, field) do {                       \
 268         STAILQ_NEXT((elm), field) = NULL;                               \
 269         *(head)->stqh_last = (elm);                                     \
 270         (head)->stqh_last = &STAILQ_NEXT((elm), field);                 \
 271 } while (0)
 272
 273 #define STAILQ_LAST(head, type, field)                                  \
 274         (STAILQ_EMPTY((head)) ?                                         \
 275                 NULL :                                                  \
 276                 ((struct type *)                                        \
 277                 ((char *)((head)->stqh_last) - asf_offsetof(struct type, field))))
 278
 279 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
 280
 281 #define STAILQ_REMOVE(head, elm, type, field) do {                      \
 282         if (STAILQ_FIRST((head)) == (elm)) {                            \
 283                 STAILQ_REMOVE_HEAD((head), field);                      \
 284         }                                                               \
 285         else {                                                          \
 286                 struct type *curelm = STAILQ_FIRST((head));             \
 287                 while (STAILQ_NEXT(curelm, field) != (elm))             \
 288                         curelm = STAILQ_NEXT(curelm, field);            \
 289                 if ((STAILQ_NEXT(curelm, field) =                       \
 290                      STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\
 291                         (head)->stqh_last = &STAILQ_NEXT((curelm), field);\
 292         }                                                               \
 293 } while (0)
 294
 295
 296 #define STAILQ_REMOVE_AFTER(head, elm, field) do {                      \
 297         if (STAILQ_NEXT(elm, field)) {          \
 298                 if ((STAILQ_NEXT(elm, field) =                  \
 299                     STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL)\
 300                         (head)->stqh_last = &STAILQ_NEXT((elm), field); \
 301         }                                                               \
 302 } while (0)
 303
 304
 305 #define STAILQ_REMOVE_HEAD(head, field) do {                            \
 306         if ((STAILQ_FIRST((head)) =                                     \
 307              STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)         \
 308                 (head)->stqh_last = &STAILQ_FIRST((head));              \
 309 } while (0)
 310
 311 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do {                 \
 312         if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \
 313                 (head)->stqh_last = &STAILQ_FIRST((head));              \
 314 } while (0)
 315
 316 /*
 317  * List declarations.
 318  */
 319 #define LIST_HEAD(name, type)                                           \
 320 struct name {                                                           \
 321         struct type *lh_first;  /* first element */                     \
 322 }
 323
 324 #define ATH_LIST_HEAD(name, type)                                       \
 325 struct name {                                                           \
 326         struct type *lh_first;  /* first element */                     \
 327 }
 328
 329 #define LIST_HEAD_INITIALIZER(head)                                     \
 330         { NULL }
 331
 332 #define LIST_ENTRY(type)                                                \
 333 struct {                                                                \
 334         struct type *le_next;   /* next element */                      \
 335         struct type **le_prev;  /* address of previous next element */  \
 336 }
 337
 338 /*
 339  * List functions.
 340  */
 341
 342 #define LIST_EMPTY(head)        ((head)->lh_first == NULL)
 343
 344 #define LIST_FIRST(head)        ((head)->lh_first)
 345
 346 #define LIST_FOREACH(var, head, field)                                  \
 347         for ((var) = LIST_FIRST((head));                                \
 348             (var);                                                      \
 349             (var) = LIST_NEXT((var), field))
 350
 351 #define LIST_FOREACH_SAFE(var, head, field, tvar)                       \
 352         for ((var) = LIST_FIRST((head));                                \
 353             (var) && ((tvar) = LIST_NEXT((var), field), 1);             \
 354             (var) = (tvar))
 355
 356 #define LIST_INIT(head) do {                                            \
 357         LIST_FIRST((head)) = NULL;                                      \
 358 } while (0)
 359
 360 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
 361         if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
 362                 LIST_NEXT((listelm), field)->field.le_prev =            \
 363                     &LIST_NEXT((elm), field);                           \
 364         LIST_NEXT((listelm), field) = (elm);                            \
 365         (elm)->field.le_prev = &LIST_NEXT((listelm), field);            \
 366 } while (0)
 367
 368 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
 369         (elm)->field.le_prev = (listelm)->field.le_prev;                \
 370         LIST_NEXT((elm), field) = (listelm);                            \
 371         *(listelm)->field.le_prev = (elm);                              \
 372         (listelm)->field.le_prev = &LIST_NEXT((elm), field);            \
 373 } while (0)
 374
 375 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
 376         if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)     \
 377                 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
 378         LIST_FIRST((head)) = (elm);                                     \
 379         (elm)->field.le_prev = &LIST_FIRST((head));                     \
 380 } while (0)
 381
 382 #define LIST_NEXT(elm, field)   ((elm)->field.le_next)
 383
 384 #define LIST_REMOVE(elm, field) do {                                    \
 385         if (LIST_NEXT((elm), field) != NULL)                            \
 386                 LIST_NEXT((elm), field)->field.le_prev =                \
 387                     (elm)->field.le_prev;                               \
 388         *(elm)->field.le_prev = LIST_NEXT((elm), field);                \
 389 } while (0)
 390
 391 /*
 392  * Tail queue declarations.
 393  */
 394 #define TAILQ_HEAD(name, type)                                          \
 395 struct name {                                                           \
 396         struct type *tqh_first; /* first element */                     \
 397         struct type **tqh_last; /* addr of last next element */         \
 398         TRACEBUF                                                        \
 399 }
 400
 401 #define TAILQ_HEAD_INITIALIZER(head)                                    \
 402         { NULL, &(head).tqh_first }
 403
 404 #define TAILQ_ENTRY(type)                                               \
 405 struct {                                                                \
 406         struct type *tqe_next;  /* next element */                      \
 407         struct type **tqe_prev; /* address of previous next element */  \
 408         TRACEBUF                                                        \
 409 }
 410
 411 /*
 412  * Tail queue functions.
 413  */
 414 #define TAILQ_CONCAT(head1, head2, field) do {                          \
 415         if (!TAILQ_EMPTY(head2)) {                                      \
 416                 *(head1)->tqh_last = (head2)->tqh_first;                \
 417                 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
 418                 (head1)->tqh_last = (head2)->tqh_last;                  \
 419                 TAILQ_INIT((head2));                                    \
 420                 QMD_TRACE_HEAD(head);                                   \
 421                 QMD_TRACE_HEAD(head2);                                  \
 422         }                                                               \
 423 } while (0)
 424
 425 #define TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
 426
 427 #define TAILQ_FIRST(head)       ((head)->tqh_first)
 428
 429 #define TAILQ_FOREACH(var, head, field)                                 \
 430         for ((var) = TAILQ_FIRST((head));                               \
 431             (var);                                                      \
 432             (var) = TAILQ_NEXT((var), field))
 433
 434 #define TAILQ_FOREACH_SAFE(var, head, field, tvar)                      \
 435         for ((var) = TAILQ_FIRST((head));                               \
 436             (var) && ((tvar) = TAILQ_NEXT((var), field), 1);            \
 437             (var) = (tvar))
 438
 439 #define TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
 440         for ((var) = TAILQ_LAST((head), headname);                      \
 441             (var);                                                      \
 442             (var) = TAILQ_PREV((var), headname, field))
 443
 444 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)    \
 445         for ((var) = TAILQ_LAST((head), headname);                      \
 446             (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
 447             (var) = (tvar))
 448
 449 #define TAILQ_INIT(head) do {                                           \
 450         TAILQ_FIRST((head)) = NULL;                                     \
 451         (head)->tqh_last = &TAILQ_FIRST((head));                        \
 452         QMD_TRACE_HEAD(head);                                           \
 453 } while (0)
 454
 455 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
 456         if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
 457                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
 458                     &TAILQ_NEXT((elm), field);                          \
 459         else {                                                          \
 460                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
 461                 QMD_TRACE_HEAD(head);                                   \
 462         }                                                               \
 463         TAILQ_NEXT((listelm), field) = (elm);                           \
 464         (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);          \
 465         QMD_TRACE_ELEM(&(elm)->field);                                  \
 466         QMD_TRACE_ELEM(&listelm->field);                                \
 467 } while (0)
 468
 469 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
 470         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
 471         TAILQ_NEXT((elm), field) = (listelm);                           \
 472         *(listelm)->field.tqe_prev = (elm);                             \
 473         (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);          \
 474         QMD_TRACE_ELEM(&(elm)->field);                                  \
 475         QMD_TRACE_ELEM(&listelm->field);                                \
 476 } while (0)
 477
 478 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
 479         if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)   \
 480                 TAILQ_FIRST((head))->field.tqe_prev =                   \
 481                     &TAILQ_NEXT((elm), field);                          \
 482         else                                                            \
 483                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
 484         TAILQ_FIRST((head)) = (elm);                                    \
 485         (elm)->field.tqe_prev = &TAILQ_FIRST((head));                   \
 486         QMD_TRACE_HEAD(head);                                           \
 487         QMD_TRACE_ELEM(&(elm)->field);                                  \
 488 } while (0)
 489
 490 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
 491         TAILQ_NEXT((elm), field) = NULL;                                \
 492         (elm)->field.tqe_prev = (head)->tqh_last;                       \
 493         *(head)->tqh_last = (elm);                                      \
 494         (head)->tqh_last = &TAILQ_NEXT((elm), field);                   \
 495         QMD_TRACE_HEAD(head);                                           \
 496         QMD_TRACE_ELEM(&(elm)->field);                                  \
 497 } while (0)
 498
 499 #define TAILQ_LAST(head, headname)                                      \
 500         (*(((struct headname *)((head)->tqh_last))->tqh_last))
 501
 502 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
 503
 504 #define TAILQ_PREV(elm, headname, field)                                \
 505         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
 506
 507 #define TAILQ_REMOVE(head, elm, field) do {                             \
 508         if ((TAILQ_NEXT((elm), field)) != NULL)                         \
 509                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
 510                     (elm)->field.tqe_prev;                              \
 511         else {                                                          \
 512                 (head)->tqh_last = (elm)->field.tqe_prev;               \
 513                 QMD_TRACE_HEAD(head);                                   \
 514         }                                                               \
 515         *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);              \
 516         TRASHIT((elm)->field.tqe_next);                                 \
 517         TRASHIT((elm)->field.tqe_prev);                                 \
 518         QMD_TRACE_ELEM(&(elm)->field);                                  \
 519 } while (0)
 520
 521
 522 #ifdef _KERNEL
 523
 524 /*
 525  * XXX insque() and remque() are an old way of handling certain queues.
 526  * They bogusly assumes that all queue heads look alike.
 527  */
 528
 529 struct quehead {
 530         struct quehead *qh_link;
 531         struct quehead *qh_rlink;
 532 };
 533
 534 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
 535
 536 static __inline void
 537 insque(void *a, void *b)
 538 {
 539         struct quehead *element = (struct quehead *)a,
 540                  *head = (struct quehead *)b;
 541
 542         element->qh_link = head->qh_link;
 543         element->qh_rlink = head;
 544         head->qh_link = element;
 545         element->qh_link->qh_rlink = element;
 546 }
 547
 548 static __inline void
 549 remque(void *a)
 550 {
 551         struct quehead *element = (struct quehead *)a;
 552
 553         element->qh_link->qh_rlink = element->qh_rlink;
 554         element->qh_rlink->qh_link = element->qh_link;
 555         element->qh_rlink = 0;
 556 }
 557
 558 #else /* !(__GNUC__ || __INTEL_COMPILER) */
 559
 560 void    insque(void *a, void *b);
 561 void    remque(void *a);
 562
 563 #endif /* __GNUC__ || __INTEL_COMPILER */
 564
 565 #endif /* _KERNEL */
 566
 567 #endif /* !_SYS_QUEUE_H_ */