xref: /openbmc/linux/arch/arc/include/asm/bitops.h (revision 20e8ef5c)
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 __ASSEMBLY__
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  */
27 static 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 
42 static 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  */
74 static 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  */
85 static inline __attribute__ ((const)) int __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  */
102 static 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  */
117 static 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  */
134 static inline __attribute__ ((const)) int __fls(unsigned long x)
135 {
136 	/* FLS insn has exactly same semantics as the API */
137 	return	__builtin_arc_fls(x);
138 }
139 
140 /*
141  * ffs = Find First Set in word (LSB to MSB)
142  * @result: [1-32], 0 if all 0's
143  */
144 static inline __attribute__ ((const)) int ffs(unsigned int x)
145 {
146 	int n;
147 
148 	asm volatile(
149 	"	ffs.f	%0, %1		\n"  /* 0:31; 31(Z) if src 0 */
150 	"	add.nz	%0, %0, 1	\n"  /* 0:31 -> 1:32 */
151 	"	mov.z	%0, 0		\n"  /* 31(Z)-> 0 */
152 	: "=r"(n)	/* Early clobber not needed */
153 	: "r"(x)
154 	: "cc");
155 
156 	return n;
157 }
158 
159 /*
160  * __ffs: Similar to ffs, but zero based (0-31)
161  */
162 static inline __attribute__ ((const)) unsigned long __ffs(unsigned long x)
163 {
164 	unsigned long n;
165 
166 	asm volatile(
167 	"	ffs.f	%0, %1		\n"  /* 0:31; 31(Z) if src 0 */
168 	"	mov.z	%0, 0		\n"  /* 31(Z)-> 0 */
169 	: "=r"(n)
170 	: "r"(x)
171 	: "cc");
172 
173 	return n;
174 
175 }
176 
177 #endif	/* CONFIG_ISA_ARCOMPACT */
178 
179 /*
180  * ffz = Find First Zero in word.
181  * @return:[0-31], 32 if all 1's
182  */
183 #define ffz(x)	__ffs(~(x))
184 
185 #include <asm-generic/bitops/hweight.h>
186 #include <asm-generic/bitops/fls64.h>
187 #include <asm-generic/bitops/sched.h>
188 #include <asm-generic/bitops/lock.h>
189 #include <asm-generic/bitops/atomic.h>
190 #include <asm-generic/bitops/non-atomic.h>
191 
192 #include <asm-generic/bitops/le.h>
193 #include <asm-generic/bitops/ext2-atomic-setbit.h>
194 
195 #endif /* !__ASSEMBLY__ */
196 
197 #endif
198