summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/include/asm/bitops.h
blob: bd3bd573d0aeef4e402f3458757362b2a5c67dfc (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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
/*
 * PowerPC atomic bit operations.
 *
 * Merged version by David Gibson <david@gibson.dropbear.id.au>.
 * Based on ppc64 versions by: Dave Engebretsen, Todd Inglett, Don
 * Reed, Pat McCarthy, Peter Bergner, Anton Blanchard.  They
 * originally took it from the ppc32 code.
 *
 * Within a word, bits are numbered LSB first.  Lot's of places make
 * this assumption by directly testing bits with (val & (1<<nr)).
 * This can cause confusion for large (> 1 word) bitmaps on a
 * big-endian system because, unlike little endian, the number of each
 * bit depends on the word size.
 *
 * The bitop functions are defined to work on unsigned longs, so for a
 * ppc64 system the bits end up numbered:
 *   |63..............0|127............64|191...........128|255...........196|
 * and on ppc32:
 *   |31.....0|63....31|95....64|127...96|159..128|191..160|223..192|255..224|
 *
 * There are a few little-endian macros used mostly for filesystem
 * bitmaps, these work on similar bit arrays layouts, but
 * byte-oriented:
 *   |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
 *
 * The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit
 * number field needs to be reversed compared to the big-endian bit
 * fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b).
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#ifndef _ASM_POWERPC_BITOPS_H
#define _ASM_POWERPC_BITOPS_H

#ifdef __KERNEL__

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

#include <linux/compiler.h>
#include <asm/asm-compat.h>
#include <asm/synch.h>

/* PPC bit number conversion */
#define PPC_BITLSHIFT(be)	(BITS_PER_LONG - 1 - (be))
#define PPC_BIT(bit)		(1UL << PPC_BITLSHIFT(bit))
#define PPC_BITMASK(bs, be)	((PPC_BIT(bs) - PPC_BIT(be)) | PPC_BIT(bs))

#include <asm/barrier.h>

/* Macro for generating the ***_bits() functions */
#define DEFINE_BITOP(fn, op, prefix)		\
static __inline__ void fn(unsigned long mask,	\
		volatile unsigned long *_p)	\
{						\
	unsigned long old;			\
	unsigned long *p = (unsigned long *)_p;	\
	__asm__ __volatile__ (			\
	prefix					\
"1:"	PPC_LLARX(%0,0,%3,0) "\n"		\
	stringify_in_c(op) "%0,%0,%2\n"		\
	PPC405_ERR77(0,%3)			\
	PPC_STLCX "%0,0,%3\n"			\
	"bne- 1b\n"				\
	: "=&r" (old), "+m" (*p)		\
	: "r" (mask), "r" (p)			\
	: "cc", "memory");			\
}

DEFINE_BITOP(set_bits, or, "")
DEFINE_BITOP(clear_bits, andc, "")
DEFINE_BITOP(clear_bits_unlock, andc, PPC_RELEASE_BARRIER)
DEFINE_BITOP(change_bits, xor, "")

static __inline__ void set_bit(int nr, volatile unsigned long *addr)
{
	set_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}

static __inline__ void clear_bit(int nr, volatile unsigned long *addr)
{
	clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}

static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr)
{
	clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr));
}

static __inline__ void change_bit(int nr, volatile unsigned long *addr)
{
	change_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}

/* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output
 * operands. */
#define DEFINE_TESTOP(fn, op, prefix, postfix, eh)	\
static __inline__ unsigned long fn(			\
		unsigned long mask,			\
		volatile unsigned long *_p)		\
{							\
	unsigned long old, t;				\
	unsigned long *p = (unsigned long *)_p;		\
	__asm__ __volatile__ (				\
	prefix						\
"1:"	PPC_LLARX(%0,0,%3,eh) "\n"			\
	stringify_in_c(op) "%1,%0,%2\n"			\
	PPC405_ERR77(0,%3)				\
	PPC_STLCX "%1,0,%3\n"				\
	"bne- 1b\n"					\
	postfix						\
	: "=&r" (old), "=&r" (t)			\
	: "r" (mask), "r" (p)				\
	: "cc", "memory");				\
	return (old & mask);				\
}

DEFINE_TESTOP(test_and_set_bits, or, PPC_ATOMIC_ENTRY_BARRIER,
	      PPC_ATOMIC_EXIT_BARRIER, 0)
DEFINE_TESTOP(test_and_set_bits_lock, or, "",
	      PPC_ACQUIRE_BARRIER, 1)
DEFINE_TESTOP(test_and_clear_bits, andc, PPC_ATOMIC_ENTRY_BARRIER,
	      PPC_ATOMIC_EXIT_BARRIER, 0)
DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER,
	      PPC_ATOMIC_EXIT_BARRIER, 0)

static __inline__ int test_and_set_bit(unsigned long nr,
				       volatile unsigned long *addr)
{
	return test_and_set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}

static __inline__ int test_and_set_bit_lock(unsigned long nr,
				       volatile unsigned long *addr)
{
	return test_and_set_bits_lock(BIT_MASK(nr),
				addr + BIT_WORD(nr)) != 0;
}

static __inline__ int test_and_clear_bit(unsigned long nr,
					 volatile unsigned long *addr)
{
	return test_and_clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}

static __inline__ int test_and_change_bit(unsigned long nr,
					  volatile unsigned long *addr)
{
	return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}

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

static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
{
	__asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory");
	__clear_bit(nr, addr);
}

/*
 * Return the zero-based bit position (LE, not IBM bit numbering) of
 * the most significant 1-bit in a double word.
 */
static __inline__ __attribute__((const))
int __ilog2(unsigned long x)
{
	int lz;

	asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x));
	return BITS_PER_LONG - 1 - lz;
}

static inline __attribute__((const))
int __ilog2_u32(u32 n)
{
	int bit;
	asm ("cntlzw %0,%1" : "=r" (bit) : "r" (n));
	return 31 - bit;
}

#ifdef __powerpc64__
static inline __attribute__((const))
int __ilog2_u64(u64 n)
{
	int bit;
	asm ("cntlzd %0,%1" : "=r" (bit) : "r" (n));
	return 63 - bit;
}
#endif

/*
 * Determines the bit position of the least significant 0 bit in the
 * specified double word. The returned bit position will be
 * zero-based, starting from the right side (63/31 - 0).
 */
static __inline__ unsigned long ffz(unsigned long x)
{
	/* no zero exists anywhere in the 8 byte area. */
	if ((x = ~x) == 0)
		return BITS_PER_LONG;

	/*
	 * Calculate the bit position of the least significant '1' bit in x
	 * (since x has been changed this will actually be the least significant
	 * '0' bit in * the original x).  Note: (x & -x) gives us a mask that
	 * is the least significant * (RIGHT-most) 1-bit of the value in x.
	 */
	return __ilog2(x & -x);
}

static __inline__ int __ffs(unsigned long x)
{
	return __ilog2(x & -x);
}

/*
 * ffs: find first bit 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)
{
	unsigned long i = (unsigned long)x;
	return __ilog2(i & -i) + 1;
}

/*
 * fls: find last (most-significant) bit set.
 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 */
static __inline__ int fls(unsigned int x)
{
	int lz;

	asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
	return 32 - lz;
}

static __inline__ unsigned long __fls(unsigned long x)
{
	return __ilog2(x);
}

/*
 * 64-bit can do this using one cntlzd (count leading zeroes doubleword)
 * instruction; for 32-bit we use the generic version, which does two
 * 32-bit fls calls.
 */
#ifdef __powerpc64__
static __inline__ int fls64(__u64 x)
{
	int lz;

	asm ("cntlzd %0,%1" : "=r" (lz) : "r" (x));
	return 64 - lz;
}
#else
#include <asm-generic/bitops/fls64.h>
#endif /* __powerpc64__ */

#ifdef CONFIG_PPC64
unsigned int __arch_hweight8(unsigned int w);
unsigned int __arch_hweight16(unsigned int w);
unsigned int __arch_hweight32(unsigned int w);
unsigned long __arch_hweight64(__u64 w);
#include <asm-generic/bitops/const_hweight.h>
#else
#include <asm-generic/bitops/hweight.h>
#endif

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

/* Little-endian versions */
#include <asm-generic/bitops/le.h>

/* Bitmap functions for the ext2 filesystem */

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

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

#endif /* __KERNEL__ */

#endif /* _ASM_POWERPC_BITOPS_H */