sym_misc.h

  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 */
 33typedef 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
 42static inline struct sym_quehead *sym_que_first(struct sym_quehead *head)
 43{
 44	return (head->flink == head) ? 0 : head->flink;
 45}
 46
 47static inline struct sym_quehead *sym_que_last(struct sym_quehead *head)
 48{
 49	return (head->blink == head) ? 0 : head->blink;
 50}
 51
 52static 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
 62static 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
 69static inline int sym_que_empty(struct sym_quehead *head)
 70{
 71	return head->flink == head;
 72}
 73
 74static 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
 91static 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
119static 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
132static 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 */