drivers/scsi/bfa/include/cs/bfa_q.h

   1 /*
   2  * Copyright (c) 2005-2009 Brocade Communications Systems, Inc.
   3  * All rights reserved
   4  * www.brocade.com
   5  *
   6  * Linux driver for Brocade Fibre Channel Host Bus Adapter.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License (GPL) Version 2 as
  10  * published by the Free Software Foundation
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  */
  17
  18 /**
  19  *  bfa_q.h Circular queue definitions.
  20  */
  21
  22 #ifndef __BFA_Q_H__
  23 #define __BFA_Q_H__
  24
  25 #define bfa_q_first(_q) ((void *)(((struct list_head *) (_q))->next))
  26 #define bfa_q_next(_qe) (((struct list_head *) (_qe))->next)
  27 #define bfa_q_prev(_qe) (((struct list_head *) (_qe))->prev)
  28
  29 /*
  30  * bfa_q_qe_init - to initialize a queue element
  31  */
  32 #define bfa_q_qe_init(_qe) {                                            \
  33         bfa_q_next(_qe) = (struct list_head *) NULL;                    \
  34         bfa_q_prev(_qe) = (struct list_head *) NULL;                    \
  35 }
  36
  37 /*
  38  * bfa_q_deq - dequeue an element from head of the queue
  39  */
  40 #define bfa_q_deq(_q, _qe) {                                            \
  41         if (!list_empty(_q)) {                                  \
  42                 (*((struct list_head **) (_qe))) = bfa_q_next(_q);      \
  43                 bfa_q_prev(bfa_q_next(*((struct list_head **) _qe))) =  \
  44                                                 (struct list_head *) (_q); \
  45                 bfa_q_next(_q) = bfa_q_next(*((struct list_head **) _qe)); \
  46                 BFA_Q_DBG_INIT(*((struct list_head **) _qe));           \
  47         } else {                                                        \
  48                 *((struct list_head **) (_qe)) = (struct list_head *) NULL; \
  49         }                                                               \
  50 }
  51
  52 /*
  53  * bfa_q_deq_tail - dequeue an element from tail of the queue
  54  */
  55 #define bfa_q_deq_tail(_q, _qe) {                                           \
  56         if (!list_empty(_q)) {                                              \
  57                 *((struct list_head **) (_qe)) = bfa_q_prev(_q);            \
  58                 bfa_q_next(bfa_q_prev(*((struct list_head **) _qe))) =      \
  59                                                 (struct list_head *) (_q);  \
  60                 bfa_q_prev(_q) = bfa_q_prev(*(struct list_head **) _qe);    \
  61                 BFA_Q_DBG_INIT(*((struct list_head **) _qe));               \
  62         } else {                                                            \
  63                 *((struct list_head **) (_qe)) = (struct list_head *) NULL; \
  64         }                                                                   \
  65 }
  66
  67 /*
  68  * #ifdef BFA_DEBUG (Using bfa_assert to check for debug_build is not
  69  * consistent across modules)
  70  */
  71 #ifndef BFA_PERF_BUILD
  72 #define BFA_Q_DBG_INIT(_qe)     bfa_q_qe_init(_qe)
  73 #else
  74 #define BFA_Q_DBG_INIT(_qe)
  75 #endif
  76
  77 #define bfa_q_is_on_q(_q, _qe)          \
  78         bfa_q_is_on_q_func(_q, (struct list_head *)(_qe))
  79 extern int bfa_q_is_on_q_func(struct list_head *q, struct list_head *qe);
  80
  81 #endif