aboutsummaryrefslogtreecommitdiffstats
path: root/arch/parisc/include/asm/bitops.h
blob: 4e833aa05a442bc3054ce0159968101af0c808a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
#ifndef _PARISC_BITOPS_H
#define _PARISC_BITOPS_H

#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif

#include <linux/compiler.h>
#include <asm/types.h>		/* for BITS_PER_LONG/SHIFT_PER_LONG */
#include <asm/byteorder.h>
#include <asm/atomic.h>

/*
 * HP-PARISC specific bit operations
 * for a detailed description of the functions please refer
 * to include/asm-i386/bitops.h or kerneldoc
 */

#define CHOP_SHIFTCOUNT(x) (((unsigned long) (x)) & (BITS_PER_LONG - 1))


#define smp_mb__before_clear_bit()      smp_mb()
#define smp_mb__after_clear_bit()       smp_mb()

/* See http://marc.theaimsgroup.com/?t=108826637900003 for discussion
 * on use of volatile and __*_bit() (set/clear/change):
 *	*_bit() want use of volatile.
 *	__*_bit() are "relaxed" and don't use spinlock or volatile.
 */

static __inline__ void set_bit(int nr, volatile unsigned long * addr)
{
	unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
	unsigned long flags;

	addr += (nr >> SHIFT_PER_LONG);
	_atomic_spin_lock_irqsave(addr, flags);
	*addr |= mask;
	_atomic_spin_unlock_irqrestore(addr, flags);
}

static __inline__ void clear_bit(int nr, volatile unsigned long * addr)
{
	unsigned long mask = ~(1UL << CHOP_SHIFTCOUNT(nr));
	unsigned long flags;

	addr += (nr >> SHIFT_PER_LONG);
	_atomic_spin_lock_irqsave(addr, flags);
	*addr &= mask;
	_atomic_spin_unlock_irqrestore(addr, flags);
}

static __inline__ void change_bit(int nr, volatile unsigned long * addr)
{
	unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
	unsigned long flags;

	addr += (nr >> SHIFT_PER_LONG);
	_atomic_spin_lock_irqsave(addr, flags);
	*addr ^= mask;
	_atomic_spin_unlock_irqrestore(addr, flags);
}

static __inline__ int test_and_set_bit(int nr, volatile unsigned long * addr)
{
	unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
	unsigned long old;
	unsigned long flags;
	int set;

	addr += (nr >> SHIFT_PER_LONG);
	_atomic_spin_lock_irqsave(addr, flags);
	old = *addr;
	set = (old & mask) ? 1 : 0;
	if (!set)
		*addr = old | mask;
	_atomic_spin_unlock_irqrestore(addr, flags);

	return set;
}

static __inline__ int test_and_clear_bit(int nr, volatile unsigned long * addr)
{
	unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
	unsigned long old;
	unsigned long flags;
	int set;

	addr += (nr >> SHIFT_PER_LONG);
	_atomic_spin_lock_irqsave(addr, flags);
	old = *addr;
	set = (old & mask) ? 1 : 0;
	if (set)
		*addr = old & ~mask;
	_atomic_spin_unlock_irqrestore(addr, flags);

	return set;
}

static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)
{
	unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
	unsigned long oldbit;
	unsigned long flags;

	addr += (nr >> SHIFT_PER_LONG);
	_atomic_spin_lock_irqsave(addr, flags);
	oldbit = *addr;
	*addr = oldbit ^ mask;
	_atomic_spin_unlock_irqrestore(addr, flags);

	return (oldbit & mask) ? 1 : 0;
}

#include <asm-generic/bitops/non-atomic.h>

#ifdef __KERNEL__

/**
 * __ffs - find first bit in word. returns 0 to "BITS_PER_LONG-1".
 * @word: The word to search
 *
 * __ffs() return is undefined if no bit is set.
 *
 * 32-bit fast __ffs by LaMont Jones "lamont At hp com".
 * 64-bit enhancement by Grant Grundler "grundler At parisc-linux org".
 * (with help from willy/jejb to get the semantics right)
 *
 * This algorithm avoids branches by making use of nullification.
 * One side effect of "extr" instructions is it sets PSW[N] bit.
 * How PSW[N] (nullify next insn) gets set is determined by the 
 * "condition" field (eg "<>" or "TR" below) in the extr* insn.
 * Only the 1st and one of either the 2cd or 3rd insn will get executed.
 * Each set of 3 insn will get executed in 2 cycles on PA8x00 vs 16 or so
 * cycles for each mispredicted branch.
 */

static __inline__ unsigned long __ffs(unsigned long x)
{
	unsigned long ret;

	__asm__(
#ifdef CONFIG_64BIT
		" ldi       63,%1\n"
		" extrd,u,*<>  %0,63,32,%%r0\n"
		" extrd,u,*TR  %0,31,32,%0\n"	/* move top 32-bits down */
		" addi    -32,%1,%1\n"
#else
		" ldi       31,%1\n"
#endif
		" extru,<>  %0,31,16,%%r0\n"
		" extru,TR  %0,15,16,%0\n"	/* xxxx0000 -> 0000xxxx */
		" addi    -16,%1,%1\n"
		" extru,<>  %0,31,8,%%r0\n"
		" extru,TR  %0,23,8,%0\n"	/* 0000xx00 -> 000000xx */
		" addi    -8,%1,%1\n"
		" extru,<>  %0,31,4,%%r0\n"
		" extru,TR  %0,27,4,%0\n"	/* 000000x0 -> 0000000x */
		" addi    -4,%1,%1\n"
		" extru,<>  %0,31,2,%%r0\n"
		" extru,TR  %0,29,2,%0\n"	/* 0000000y, 1100b -> 0011b */
		" addi    -2,%1,%1\n"
		" extru,=  %0,31,1,%%r0\n"	/* check last bit */
		" addi    -1,%1,%1\n"
			: "+r" (x), "=r" (ret) );
	return ret;
}

#include <asm-generic/bitops/ffz.h>

/*
 * ffs: find first bit set. returns 1 to BITS_PER_LONG or 0 (if none set)
 * This is defined the same way as the libc and compiler builtin
 * ffs routines, therefore differs in spirit from the above ffz (man ffs).
 */
static __inline__ int ffs(int x)
{
	return x ? (__ffs((unsigned long)x) + 1) : 0;
}

/*
 * fls: find last (most significant) bit set.
 * fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 */

static __inline__ int fls(int x)
{
	int ret;
	if (!x)
		return 0;

	__asm__(
	"	ldi		1,%1\n"
	"	extru,<>	%0,15,16,%%r0\n"
	"	zdep,TR		%0,15,16,%0\n"		/* xxxx0000 */
	"	addi		16,%1,%1\n"
	"	extru,<>	%0,7,8,%%r0\n"
	"	zdep,TR		%0,23,24,%0\n"		/* xx000000 */
	"	addi		8,%1,%1\n"
	"	extru,<>	%0,3,4,%%r0\n"
	"	zdep,TR		%0,27,28,%0\n"		/* x0000000 */
	"	addi		4,%1,%1\n"
	"	extru,<>	%0,1,2,%%r0\n"
	"	zdep,TR		%0,29,30,%0\n"		/* y0000000 (y&3 = 0) */
	"	addi		2,%1,%1\n"
	"	extru,=		%0,0,1,%%r0\n"
	"	addi		1,%1,%1\n"		/* if y & 8, add 1 */
		: "+r" (x), "=r" (ret) );

	return ret;
}

#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
#include <asm-generic/bitops/sched.h>

#endif /* __KERNEL__ */

#include <asm-generic/bitops/find.h>

#ifdef __KERNEL__

#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic-setbit.h>

#endif	/* __KERNEL__ */

#endif /* _PARISC_BITOPS_H */

Privacy Policy