xref: /linux/drivers/scsi/sym53c8xx_2/sym_misc.h (revision 75bf465f0bc33e9b776a46d6a1b9b990f5fb7c37)
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