projects/linux·blob master · refs

199 lines · 3.8 KiB

1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6#ifndef _ASM_BITOPS_H
7#define _ASM_BITOPS_H
8
9#ifndef _LINUX_BITOPS_H
10#error only <linux/bitops.h> can be included directly
11#endif
12
13#ifndef __ASSEMBLER__
14
15#include <linux/types.h>
16#include <linux/compiler.h>
17
18#ifdef CONFIG_ISA_ARCOMPACT
19
20/*
21 * Count the number of zeros, starting from MSB
22 * Helper for fls( ) friends
23 * This is a pure count, so (1-32) or (0-31) doesn't apply
24 * It could be 0 to 32, based on num of 0's in there
25 * clz(0x8000_0000) = 0, clz(0xFFFF_FFFF)=0, clz(0) = 32, clz(1) = 31
26 */
27static inline __attribute__ ((const)) int clz(unsigned int x)
28{
29 unsigned int res;
30
31 __asm__ __volatile__(
32 " norm.f %0, %1 \n"
33 " mov.n %0, 0 \n"
34 " add.p %0, %0, 1 \n"
35 : "=r"(res)
36 : "r"(x)
37 : "cc");
38
39 return res;
40}
41
42static inline int constant_fls(unsigned int x)
43{
44 int r = 32;
45
46 if (!x)
47 return 0;
48 if (!(x & 0xffff0000u)) {
49 x <<= 16;
50 r -= 16;
51 }
52 if (!(x & 0xff000000u)) {
53 x <<= 8;
54 r -= 8;
55 }
56 if (!(x & 0xf0000000u)) {
57 x <<= 4;
58 r -= 4;
59 }
60 if (!(x & 0xc0000000u)) {
61 x <<= 2;
62 r -= 2;
63 }
64 if (!(x & 0x80000000u))
65 r -= 1;
66 return r;
67}
68
69/*
70 * fls = Find Last Set in word
71 * @result: [1-32]
72 * fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0
73 */
74static inline __attribute__ ((const)) int fls(unsigned int x)
75{
76 if (__builtin_constant_p(x))
77 return constant_fls(x);
78
79 return 32 - clz(x);
80}
81
82/*
83 * __fls: Similar to fls, but zero based (0-31)
84 */
85static inline __attribute__ ((const)) unsigned long __fls(unsigned long x)
86{
87 if (!x)
88 return 0;
89 else
90 return fls(x) - 1;
91}
92
93/*
94 * ffs = Find First Set in word (LSB to MSB)
95 * @result: [1-32], 0 if all 0's
96 */
97#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); })
98
99/*
100 * __ffs: Similar to ffs, but zero based (0-31)
101 */
102static inline __attribute__ ((const)) unsigned long __ffs(unsigned long word)
103{
104 if (!word)
105 return word;
106
107 return ffs(word) - 1;
108}
109
110#else /* CONFIG_ISA_ARCV2 */
111
112/*
113 * fls = Find Last Set in word
114 * @result: [1-32]
115 * fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0
116 */
117static inline __attribute__ ((const)) int fls(unsigned int x)
118{
119 int n;
120
121 asm volatile(
122 " fls.f %0, %1 \n" /* 0:31; 0(Z) if src 0 */
123 " add.nz %0, %0, 1 \n" /* 0:31 -> 1:32 */
124 : "=r"(n) /* Early clobber not needed */
125 : "r"(x)
126 : "cc");
127
128 return n;
129}
130
131/*
132 * __fls: Similar to fls, but zero based (0-31). Also 0 if no bit set
133 */
134static inline __attribute__ ((const)) unsigned long __fls(unsigned long x)
135{
136 if (__builtin_constant_p(x))
137 return x ? BITS_PER_LONG - 1 - __builtin_clzl(x) : 0;
138 /* FLS insn has exactly same semantics as the API */
139 return __builtin_arc_fls(x);
140}
141
142/*
143 * ffs = Find First Set in word (LSB to MSB)
144 * @result: [1-32], 0 if all 0's
145 */
146static inline __attribute__ ((const)) int ffs(unsigned int x)
147{
148 int n;
149
150 asm volatile(
151 " ffs.f %0, %1 \n" /* 0:31; 31(Z) if src 0 */
152 " add.nz %0, %0, 1 \n" /* 0:31 -> 1:32 */
153 " mov.z %0, 0 \n" /* 31(Z)-> 0 */
154 : "=r"(n) /* Early clobber not needed */
155 : "r"(x)
156 : "cc");
157
158 return n;
159}
160
161/*
162 * __ffs: Similar to ffs, but zero based (0-31)
163 */
164static inline __attribute__ ((const)) unsigned long __ffs(unsigned long x)
165{
166 unsigned long n;
167
168 asm volatile(
169 " ffs.f %0, %1 \n" /* 0:31; 31(Z) if src 0 */
170 " mov.z %0, 0 \n" /* 31(Z)-> 0 */
171 : "=r"(n)
172 : "r"(x)
173 : "cc");
174
175 return n;
176
177}
178
179#endif /* CONFIG_ISA_ARCOMPACT */
180
181/*
182 * ffz = Find First Zero in word.
183 * @return:[0-31], 32 if all 1's
184 */
185#define ffz(x) __ffs(~(x))
186
187#include <asm-generic/bitops/hweight.h>
188#include <asm-generic/bitops/fls64.h>
189#include <asm-generic/bitops/sched.h>
190#include <asm-generic/bitops/lock.h>
191#include <asm-generic/bitops/atomic.h>
192#include <asm-generic/bitops/non-atomic.h>
193
194#include <asm-generic/bitops/le.h>
195#include <asm-generic/bitops/ext2-atomic-setbit.h>
196
197#endif /* !__ASSEMBLER__ */
198
199#endif