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sym_misc.h
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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 <[email protected]>
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 <[email protected]>
15  * Stefan Esser <[email protected]>
16  * Copyright (C) 1994 Wolfgang Stanglmeier
17  *
18  * Other major contributions:
19  *
20  * NVRAM detection and reading.
21  * Copyright (C) 1997 Richard Waltham <[email protected]>
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 */