1 /* 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
__clear_bit(unsigned long nr,volatile void * addr)60 static inline void __clear_bit(unsigned long 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 */
test_bit(unsigned long nr,const volatile void * addr)73 static inline int test_bit(unsigned long nr, const volatile void *addr)
74 {
75 return 1UL & (((const volatile unsigned int *) addr)[nr >> 5] >> (nr & 31));
76 }
77
78 /*
79 * change bit
80 */
__change_bit(unsigned long nr,volatile void * addr)81 static inline void __change_bit(unsigned long 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
91 extern void change_bit(unsigned long 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 */
__test_and_change_bit(unsigned long nr,volatile void * addr)138 static inline int __test_and_change_bit(unsigned long 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
151 extern int test_and_change_bit(unsigned long 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 */
164 static inline __attribute__((const))
__ffs(unsigned long x)165 unsigned long __ffs(unsigned long x)
166 {
167 int bit;
168 asm("bsch %2,%0" : "=r"(bit) : "0"(0), "r"(x & -x) : "cc");
169 return bit;
170 }
171
172 /*
173 * special slimline version of fls() for calculating ilog2_u32()
174 * - note: no protection against n == 0
175 */
176 static inline __attribute__((const))
__ilog2_u32(u32 n)177 int __ilog2_u32(u32 n)
178 {
179 int bit;
180 asm("bsch %2,%0" : "=r"(bit) : "0"(0), "r"(n) : "cc");
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 */
192 static inline __attribute__((const))
fls(int x)193 int fls(int x)
194 {
195 return (x != 0) ? __ilog2_u32(x) + 1 : 0;
196 }
197
198 /**
199 * __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 */
__fls(unsigned long word)204 static inline unsigned long __fls(unsigned long word)
205 {
206 return __ilog2_u32(word);
207 }
208
209 /**
210 * 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 */
216 static inline __attribute__((const))
ffs(int x)217 int 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 #include <asm-generic/bitops/ext2-atomic-setbit.h>
231 #include <asm-generic/bitops/le.h>
232
233 #endif /* __KERNEL__ */
234 #endif /* __ASM_BITOPS_H */
235