drivers/scsi/sym53c8xx_2/sym_misc.h

   1 /*
   2  * Device driver for the SYMBIOS/LSILOGIC 53C8XX and 53C1010 family
   3  * of PCI-SCSI IO processors.
   4  *
   5  * Copyright (C) 1999-2001  Gerard Roudier <groudier@free.fr>
   6  *
   7  * This driver is derived from the Linux sym53c8xx driver.
   8  * Copyright (C) 1998-2000  Gerard Roudier
   9  *
  10  * The sym53c8xx driver is derived from the ncr53c8xx driver that had been
  11  * a port of the FreeBSD ncr driver to Linux-1.2.13.
  12  *
  13  * The original ncr driver has been written for 386bsd and FreeBSD by
  14  *         Wolfgang Stanglmeier        <wolf@cologne.de>
  15  *         Stefan Esser                <se@mi.Uni-Koeln.de>
  16  * Copyright (C) 1994  Wolfgang Stanglmeier
  17  *
  18  * Other major contributions:
  19  *
  20  * NVRAM detection and reading.
  21  * Copyright (C) 1997 Richard Waltham <dormouse@farsrobt.demon.co.uk>
  22  *
  23  *-----------------------------------------------------------------------------
  24  *
  25  * This program is free software; you can redistribute it and/or modify
  26  * it under the terms of the GNU General Public License as published by
  27  * the Free Software Foundation; either version 2 of the License, or
  28  * (at your option) any later version.
  29  *
  30  * This program is distributed in the hope that it will be useful,
  31  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  33  * GNU General Public License for more details.
  34  *
  35  * You should have received a copy of the GNU General Public License
  36  * along with this program; if not, write to the Free Software
  37  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  38  */
  39
  40 #ifndef SYM_MISC_H
  41 #define SYM_MISC_H
  42
  43 /*
  44  *  A la VMS/CAM-3 queue management.
  45  */
  46 typedef struct sym_quehead {
  47         struct sym_quehead *flink;      /* Forward  pointer */
  48         struct sym_quehead *blink;      /* Backward pointer */
  49 } SYM_QUEHEAD;
  50
  51 #define sym_que_init(ptr) do { \
  52         (ptr)->flink = (ptr); (ptr)->blink = (ptr); \
  53 } while (0)
  54
  55 static inline struct sym_quehead *sym_que_first(struct sym_quehead *head)
  56 {
  57         return (head->flink == head) ? 0 : head->flink;
  58 }
  59
  60 static inline struct sym_quehead *sym_que_last(struct sym_quehead *head)
  61 {
  62         return (head->blink == head) ? 0 : head->blink;
  63 }
  64
  65 static inline void __sym_que_add(struct sym_quehead * new,
  66         struct sym_quehead * blink,
  67         struct sym_quehead * flink)
  68 {
  69         flink->blink    = new;
  70         new->flink      = flink;
  71         new->blink      = blink;
  72         blink->flink    = new;
  73 }
  74
  75 static inline void __sym_que_del(struct sym_quehead * blink,
  76         struct sym_quehead * flink)
  77 {
  78         flink->blink = blink;
  79         blink->flink = flink;
  80 }
  81
  82 static inline int sym_que_empty(struct sym_quehead *head)
  83 {
  84         return head->flink == head;
  85 }
  86
  87 static inline void sym_que_splice(struct sym_quehead *list,
  88         struct sym_quehead *head)
  89 {
  90         struct sym_quehead *first = list->flink;
  91
  92         if (first != list) {
  93                 struct sym_quehead *last = list->blink;
  94                 struct sym_quehead *at   = head->flink;
  95
  96                 first->blink = head;
  97                 head->flink  = first;
  98
  99                 last->flink = at;
 100                 at->blink   = last;
 101         }
 102 }
 103
 104 static inline void sym_que_move(struct sym_quehead *orig,
 105         struct sym_quehead *dest)
 106 {
 107         struct sym_quehead *first, *last;
 108
 109         first = orig->flink;
 110         if (first != orig) {
 111                 first->blink = dest;
 112                 dest->flink  = first;
 113                 last = orig->blink;
 114                 last->flink  = dest;
 115                 dest->blink  = last;
 116                 orig->flink  = orig;
 117                 orig->blink  = orig;
 118         } else {
 119                 dest->flink  = dest;
 120                 dest->blink  = dest;
 121         }
 122 }
 123
 124 #define sym_que_entry(ptr, type, member) container_of(ptr, type, member)
 125
 126 #define sym_insque(new, pos)            __sym_que_add(new, pos, (pos)->flink)
 127
 128 #define sym_remque(el)                  __sym_que_del((el)->blink, (el)->flink)
 129
 130 #define sym_insque_head(new, head)      __sym_que_add(new, head, (head)->flink)
 131
 132 static inline struct sym_quehead *sym_remque_head(struct sym_quehead *head)
 133 {
 134         struct sym_quehead *elem = head->flink;
 135
 136         if (elem != head)
 137                 __sym_que_del(head, elem->flink);
 138         else
 139                 elem = NULL;
 140         return elem;
 141 }
 142
 143 #define sym_insque_tail(new, head)      __sym_que_add(new, (head)->blink, head)
 144
 145 static inline struct sym_quehead *sym_remque_tail(struct sym_quehead *head)
 146 {
 147         struct sym_quehead *elem = head->blink;
 148
 149         if (elem != head)
 150                 __sym_que_del(elem->blink, head);
 151         else
 152                 elem = 0;
 153         return elem;
 154 }
 155
 156 /*
 157  *  This one may be useful.
 158  */
 159 #define FOR_EACH_QUEUED_ELEMENT(head, qp) \
 160         for (qp = (head)->flink; qp != (head); qp = qp->flink)
 161 /*
 162  *  FreeBSD does not offer our kind of queue in the CAM CCB.
 163  *  So, we have to cast.
 164  */
 165 #define sym_qptr(p)     ((struct sym_quehead *) (p))
 166
 167 /*
 168  *  Simple bitmap operations.
 169  */
 170 #define sym_set_bit(p, n)       (((u32 *)(p))[(n)>>5] |=  (1<<((n)&0x1f)))
 171 #define sym_clr_bit(p, n)       (((u32 *)(p))[(n)>>5] &= ~(1<<((n)&0x1f)))
 172 #define sym_is_bit(p, n)        (((u32 *)(p))[(n)>>5] &   (1<<((n)&0x1f)))
 173
 174 /*
 175  * The below round up/down macros are to be used with a constant
 176  * as argument (sizeof(...) for example), for the compiler to
 177  * optimize the whole thing.
 178  */
 179 #define _U_(a,m)        (a)<=(1<<m)?m:
 180
 181 /*
 182  * Round up logarithm to base 2 of a 16 bit constant.
 183  */
 184 #define _LGRU16_(a) \
 185 ( \
 186  _U_(a, 0)_U_(a, 1)_U_(a, 2)_U_(a, 3)_U_(a, 4)_U_(a, 5)_U_(a, 6)_U_(a, 7) \
 187  _U_(a, 8)_U_(a, 9)_U_(a,10)_U_(a,11)_U_(a,12)_U_(a,13)_U_(a,14)_U_(a,15) \
 188  16)
 189
 190 #endif /* SYM_MISC_H */