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David Howellsb920de12008-02-08 04:19:31 -08001/* MN10300 bit operations
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 *
11 * These have to be done with inline assembly: that way the bit-setting
12 * is guaranteed to be atomic. All bit operations return 0 if the bit
13 * was cleared before the operation and != 0 if it was not.
14 *
15 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
16 */
17#ifndef __ASM_BITOPS_H
18#define __ASM_BITOPS_H
19
20#include <asm/cpu-regs.h>
21
22#define smp_mb__before_clear_bit() barrier()
23#define smp_mb__after_clear_bit() barrier()
24
25/*
26 * set bit
27 */
28#define __set_bit(nr, addr) \
29({ \
30 volatile unsigned char *_a = (unsigned char *)(addr); \
31 const unsigned shift = (nr) & 7; \
32 _a += (nr) >> 3; \
33 \
34 asm volatile("bset %2,(%1) # set_bit reg" \
35 : "=m"(*_a) \
36 : "a"(_a), "d"(1 << shift), "m"(*_a) \
37 : "memory", "cc"); \
38})
39
40#define set_bit(nr, addr) __set_bit((nr), (addr))
41
42/*
43 * clear bit
44 */
45#define ___clear_bit(nr, addr) \
46({ \
47 volatile unsigned char *_a = (unsigned char *)(addr); \
48 const unsigned shift = (nr) & 7; \
49 _a += (nr) >> 3; \
50 \
51 asm volatile("bclr %2,(%1) # clear_bit reg" \
52 : "=m"(*_a) \
53 : "a"(_a), "d"(1 << shift), "m"(*_a) \
54 : "memory", "cc"); \
55})
56
57#define clear_bit(nr, addr) ___clear_bit((nr), (addr))
58
59
60static inline void __clear_bit(int nr, volatile void *addr)
61{
62 unsigned int *a = (unsigned int *) addr;
63 int mask;
64
65 a += nr >> 5;
66 mask = 1 << (nr & 0x1f);
67 *a &= ~mask;
68}
69
70/*
71 * test bit
72 */
73static inline int test_bit(int nr, const volatile void *addr)
74{
75 return 1UL & (((const unsigned int *) addr)[nr >> 5] >> (nr & 31));
76}
77
78/*
79 * change bit
80 */
81static inline void __change_bit(int nr, volatile void *addr)
82{
83 int mask;
84 unsigned int *a = (unsigned int *) addr;
85
86 a += nr >> 5;
87 mask = 1 << (nr & 0x1f);
88 *a ^= mask;
89}
90
91extern void change_bit(int nr, volatile void *addr);
92
93/*
94 * test and set bit
95 */
96#define __test_and_set_bit(nr,addr) \
97({ \
98 volatile unsigned char *_a = (unsigned char *)(addr); \
99 const unsigned shift = (nr) & 7; \
100 unsigned epsw; \
101 _a += (nr) >> 3; \
102 \
103 asm volatile("bset %3,(%2) # test_set_bit reg\n" \
104 "mov epsw,%1" \
105 : "=m"(*_a), "=d"(epsw) \
106 : "a"(_a), "d"(1 << shift), "m"(*_a) \
107 : "memory", "cc"); \
108 \
109 !(epsw & EPSW_FLAG_Z); \
110})
111
112#define test_and_set_bit(nr, addr) __test_and_set_bit((nr), (addr))
113
114/*
115 * test and clear bit
116 */
117#define __test_and_clear_bit(nr, addr) \
118({ \
119 volatile unsigned char *_a = (unsigned char *)(addr); \
120 const unsigned shift = (nr) & 7; \
121 unsigned epsw; \
122 _a += (nr) >> 3; \
123 \
124 asm volatile("bclr %3,(%2) # test_clear_bit reg\n" \
125 "mov epsw,%1" \
126 : "=m"(*_a), "=d"(epsw) \
127 : "a"(_a), "d"(1 << shift), "m"(*_a) \
128 : "memory", "cc"); \
129 \
130 !(epsw & EPSW_FLAG_Z); \
131})
132
133#define test_and_clear_bit(nr, addr) __test_and_clear_bit((nr), (addr))
134
135/*
136 * test and change bit
137 */
138static inline int __test_and_change_bit(int nr, volatile void *addr)
139{
140 int mask, retval;
141 unsigned int *a = (unsigned int *)addr;
142
143 a += nr >> 5;
144 mask = 1 << (nr & 0x1f);
145 retval = (mask & *a) != 0;
146 *a ^= mask;
147
148 return retval;
149}
150
151extern int test_and_change_bit(int nr, volatile void *addr);
152
153#include <asm-generic/bitops/lock.h>
154
155#ifdef __KERNEL__
156
157/**
158 * __ffs - find first bit set
159 * @x: the word to search
160 *
161 * - return 31..0 to indicate bit 31..0 most least significant bit set
162 * - if no bits are set in x, the result is undefined
163 */
164static inline __attribute__((const))
165unsigned long __ffs(unsigned long x)
166{
167 int bit;
168 asm("bsch %2,%0" : "=r"(bit) : "0"(0), "r"(x & -x));
169 return bit;
170}
171
172/*
173 * special slimline version of fls() for calculating ilog2_u32()
174 * - note: no protection against n == 0
175 */
176static inline __attribute__((const))
177int __ilog2_u32(u32 n)
178{
179 int bit;
180 asm("bsch %2,%0" : "=r"(bit) : "0"(0), "r"(n));
181 return bit;
182}
183
184/**
185 * fls - find last bit set
186 * @x: the word to search
187 *
188 * This is defined the same way as ffs:
189 * - return 32..1 to indicate bit 31..0 most significant bit set
190 * - return 0 to indicate no bits set
191 */
192static inline __attribute__((const))
193int fls(int x)
194{
195 return (x != 0) ? __ilog2_u32(x) + 1 : 0;
196}
197
198/**
Rusty Russell5c134da2009-01-03 16:19:03 +1030199 * __fls - find last (most-significant) set bit in a long word
200 * @word: the word to search
201 *
202 * Undefined if no set bit exists, so code should check against 0 first.
203 */
204static inline unsigned long __fls(unsigned long word)
205{
206 return __ilog2_u32(word);
207}
208
209/**
David Howellsb920de12008-02-08 04:19:31 -0800210 * ffs - find first bit set
211 * @x: the word to search
212 *
213 * - return 32..1 to indicate bit 31..0 most least significant bit set
214 * - return 0 to indicate no bits set
215 */
216static inline __attribute__((const))
217int ffs(int x)
218{
219 /* Note: (x & -x) gives us a mask that is the least significant
220 * (rightmost) 1-bit of the value in x.
221 */
222 return fls(x & -x);
223}
224
225#include <asm-generic/bitops/ffz.h>
226#include <asm-generic/bitops/fls64.h>
227#include <asm-generic/bitops/find.h>
228#include <asm-generic/bitops/sched.h>
229#include <asm-generic/bitops/hweight.h>
230
231#define ext2_set_bit_atomic(lock, nr, addr) \
232 test_and_set_bit((nr) ^ 0x18, (addr))
233#define ext2_clear_bit_atomic(lock, nr, addr) \
234 test_and_clear_bit((nr) ^ 0x18, (addr))
235
236#include <asm-generic/bitops/ext2-non-atomic.h>
237#include <asm-generic/bitops/minix-le.h>
238
239#endif /* __KERNEL__ */
240#endif /* __ASM_BITOPS_H */