1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Device driver for the SYMBIOS/LSILOGIC 53C8XX and 53C1010 family
4  * of PCI-SCSI IO processors.
5  *
6  * Copyright (C) 1999-2001  Gerard Roudier <groudier@free.fr>
7  *
8  * This driver is derived from the Linux sym53c8xx driver.
9  * Copyright (C) 1998-2000  Gerard Roudier
10  *
11  * The sym53c8xx driver is derived from the ncr53c8xx driver that had been
12  * a port of the FreeBSD ncr driver to Linux-1.2.13.
13  *
14  * The original ncr driver has been written for 386bsd and FreeBSD by
15  *         Wolfgang Stanglmeier        <wolf@cologne.de>
16  *         Stefan Esser                <se@mi.Uni-Koeln.de>
17  * Copyright (C) 1994  Wolfgang Stanglmeier
18  *
19  * Other major contributions:
20  *
21  * NVRAM detection and reading.
22  * Copyright (C) 1997 Richard Waltham <dormouse@farsrobt.demon.co.uk>
23  *
24  *-----------------------------------------------------------------------------
25  */
26 
27 #ifndef SYM_MISC_H
28 #define SYM_MISC_H
29 
30 /*
31  *  A la VMS/CAM-3 queue management.
32  */
33 typedef struct sym_quehead {
34 	struct sym_quehead *flink;	/* Forward  pointer */
35 	struct sym_quehead *blink;	/* Backward pointer */
36 } SYM_QUEHEAD;
37 
38 #define sym_que_init(ptr) do { \
39 	(ptr)->flink = (ptr); (ptr)->blink = (ptr); \
40 } while (0)
41 
42 static inline struct sym_quehead *sym_que_first(struct sym_quehead *head)
43 {
44 	return (head->flink == head) ? 0 : head->flink;
45 }
46 
47 static inline struct sym_quehead *sym_que_last(struct sym_quehead *head)
48 {
49 	return (head->blink == head) ? 0 : head->blink;
50 }
51 
52 static inline void __sym_que_add(struct sym_quehead * new,
53 	struct sym_quehead * blink,
54 	struct sym_quehead * flink)
55 {
56 	flink->blink	= new;
57 	new->flink	= flink;
58 	new->blink	= blink;
59 	blink->flink	= new;
60 }
61 
62 static inline void __sym_que_del(struct sym_quehead * blink,
63 	struct sym_quehead * flink)
64 {
65 	flink->blink = blink;
66 	blink->flink = flink;
67 }
68 
69 static inline int sym_que_empty(struct sym_quehead *head)
70 {
71 	return head->flink == head;
72 }
73 
74 static inline void sym_que_splice(struct sym_quehead *list,
75 	struct sym_quehead *head)
76 {
77 	struct sym_quehead *first = list->flink;
78 
79 	if (first != list) {
80 		struct sym_quehead *last = list->blink;
81 		struct sym_quehead *at   = head->flink;
82 
83 		first->blink = head;
84 		head->flink  = first;
85 
86 		last->flink = at;
87 		at->blink   = last;
88 	}
89 }
90 
91 static inline void sym_que_move(struct sym_quehead *orig,
92 	struct sym_quehead *dest)
93 {
94 	struct sym_quehead *first, *last;
95 
96 	first = orig->flink;
97 	if (first != orig) {
98 		first->blink = dest;
99 		dest->flink  = first;
100 		last = orig->blink;
101 		last->flink  = dest;
102 		dest->blink  = last;
103 		orig->flink  = orig;
104 		orig->blink  = orig;
105 	} else {
106 		dest->flink  = dest;
107 		dest->blink  = dest;
108 	}
109 }
110 
111 #define sym_que_entry(ptr, type, member) container_of(ptr, type, member)
112 
113 #define sym_insque(new, pos)		__sym_que_add(new, pos, (pos)->flink)
114 
115 #define sym_remque(el)			__sym_que_del((el)->blink, (el)->flink)
116 
117 #define sym_insque_head(new, head)	__sym_que_add(new, head, (head)->flink)
118 
119 static inline struct sym_quehead *sym_remque_head(struct sym_quehead *head)
120 {
121 	struct sym_quehead *elem = head->flink;
122 
123 	if (elem != head)
124 		__sym_que_del(head, elem->flink);
125 	else
126 		elem = NULL;
127 	return elem;
128 }
129 
130 #define sym_insque_tail(new, head)	__sym_que_add(new, (head)->blink, head)
131 
132 static inline struct sym_quehead *sym_remque_tail(struct sym_quehead *head)
133 {
134 	struct sym_quehead *elem = head->blink;
135 
136 	if (elem != head)
137 		__sym_que_del(elem->blink, head);
138 	else
139 		elem = 0;
140 	return elem;
141 }
142 
143 /*
144  *  This one may be useful.
145  */
146 #define FOR_EACH_QUEUED_ELEMENT(head, qp) \
147 	for (qp = (head)->flink; qp != (head); qp = qp->flink)
148 /*
149  *  FreeBSD does not offer our kind of queue in the CAM CCB.
150  *  So, we have to cast.
151  */
152 #define sym_qptr(p)	((struct sym_quehead *) (p))
153 
154 /*
155  *  Simple bitmap operations.
156  */
157 #define sym_set_bit(p, n)	(((u32 *)(p))[(n)>>5] |=  (1<<((n)&0x1f)))
158 #define sym_clr_bit(p, n)	(((u32 *)(p))[(n)>>5] &= ~(1<<((n)&0x1f)))
159 #define sym_is_bit(p, n)	(((u32 *)(p))[(n)>>5] &   (1<<((n)&0x1f)))
160 
161 /*
162  * The below round up/down macros are to be used with a constant
163  * as argument (sizeof(...) for example), for the compiler to
164  * optimize the whole thing.
165  */
166 #define _U_(a,m)	(a)<=(1<<m)?m:
167 
168 /*
169  * Round up logarithm to base 2 of a 16 bit constant.
170  */
171 #define _LGRU16_(a) \
172 ( \
173  _U_(a, 0)_U_(a, 1)_U_(a, 2)_U_(a, 3)_U_(a, 4)_U_(a, 5)_U_(a, 6)_U_(a, 7) \
174  _U_(a, 8)_U_(a, 9)_U_(a,10)_U_(a,11)_U_(a,12)_U_(a,13)_U_(a,14)_U_(a,15) \
175  16)
176 
177 #endif /* SYM_MISC_H */
178