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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright IBM Corp. 1999,2013
4 *
5 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
6 *
7 * The description below was taken in large parts from the powerpc
8 * bitops header file:
9 * Within a word, bits are numbered LSB first. Lot's of places make
10 * this assumption by directly testing bits with (val & (1<<nr)).
11 * This can cause confusion for large (> 1 word) bitmaps on a
12 * big-endian system because, unlike little endian, the number of each
13 * bit depends on the word size.
14 *
15 * The bitop functions are defined to work on unsigned longs, so the bits
16 * end up numbered:
17 * |63..............0|127............64|191...........128|255...........192|
18 *
19 * We also have special functions which work with an MSB0 encoding.
20 * The bits are numbered:
21 * |0..............63|64............127|128...........191|192...........255|
22 *
23 * The main difference is that bit 0-63 in the bit number field needs to be
24 * reversed compared to the LSB0 encoded bit fields. This can be achieved by
25 * XOR with 0x3f.
26 *
27 */
28
29#ifndef _S390_BITOPS_H
30#define _S390_BITOPS_H
31
32#ifndef _LINUX_BITOPS_H
33#error only <linux/bitops.h> can be included directly
34#endif
35
36#include <linux/typecheck.h>
37#include <linux/compiler.h>
38#include <linux/types.h>
39#include <asm/asm.h>
40
41#define arch___set_bit generic___set_bit
42#define arch___clear_bit generic___clear_bit
43#define arch___change_bit generic___change_bit
44#define arch___test_and_set_bit generic___test_and_set_bit
45#define arch___test_and_clear_bit generic___test_and_clear_bit
46#define arch___test_and_change_bit generic___test_and_change_bit
47#define arch_test_bit_acquire generic_test_bit_acquire
48
49static __always_inline bool arch_test_bit(unsigned long nr, const volatile unsigned long *ptr)
50{
51#ifdef __HAVE_ASM_FLAG_OUTPUTS__
52 const volatile unsigned char *addr;
53 unsigned long mask;
54 int cc;
55
56 /*
57 * With CONFIG_PROFILE_ALL_BRANCHES enabled gcc fails to
58 * handle __builtin_constant_p() in some cases.
59 */
60 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && __builtin_constant_p(nr)) {
61 addr = (const volatile unsigned char *)ptr;
62 addr += (nr ^ (BITS_PER_LONG - BITS_PER_BYTE)) / BITS_PER_BYTE;
63 mask = 1UL << (nr & (BITS_PER_BYTE - 1));
64 asm volatile(
65 " tm %[addr],%[mask]"
66 : "=@cc" (cc)
67 : [addr] "Q" (*addr), [mask] "I" (mask)
68 );
69 return cc == 3;
70 }
71#endif
72 return generic_test_bit(nr, ptr);
73}
74
75#include <asm-generic/bitops/atomic.h>
76#include <asm-generic/bitops/non-instrumented-non-atomic.h>
77#include <asm-generic/bitops/lock.h>
78
79/*
80 * Functions which use MSB0 bit numbering.
81 * The bits are numbered:
82 * |0..............63|64............127|128...........191|192...........255|
83 */
84unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
85unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
86 unsigned long offset);
87
88#define for_each_set_bit_inv(bit, addr, size) \
89 for ((bit) = find_first_bit_inv((addr), (size)); \
90 (bit) < (size); \
91 (bit) = find_next_bit_inv((addr), (size), (bit) + 1))
92
93static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
94{
95 return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
96}
97
98static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
99{
100 return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
101}
102
103static inline bool test_and_clear_bit_inv(unsigned long nr,
104 volatile unsigned long *ptr)
105{
106 return test_and_clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
107}
108
109static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
110{
111 return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
112}
113
114static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
115{
116 return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
117}
118
119static inline bool test_bit_inv(unsigned long nr,
120 const volatile unsigned long *ptr)
121{
122 return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
123}
124
125#ifndef CONFIG_CC_HAS_BUILTIN_FFS
126
127/**
128 * __flogr - find leftmost one
129 * @word - The word to search
130 *
131 * Returns the bit number of the most significant bit set,
132 * where the most significant bit has bit number 0.
133 * If no bit is set this function returns 64.
134 */
135static __always_inline __attribute_const__ unsigned long __flogr(unsigned long word)
136{
137 unsigned long bit;
138
139 if (__builtin_constant_p(word)) {
140 bit = 0;
141 if (!word)
142 return 64;
143 if (!(word & 0xffffffff00000000UL)) {
144 word <<= 32;
145 bit += 32;
146 }
147 if (!(word & 0xffff000000000000UL)) {
148 word <<= 16;
149 bit += 16;
150 }
151 if (!(word & 0xff00000000000000UL)) {
152 word <<= 8;
153 bit += 8;
154 }
155 if (!(word & 0xf000000000000000UL)) {
156 word <<= 4;
157 bit += 4;
158 }
159 if (!(word & 0xc000000000000000UL)) {
160 word <<= 2;
161 bit += 2;
162 }
163 if (!(word & 0x8000000000000000UL)) {
164 word <<= 1;
165 bit += 1;
166 }
167 return bit;
168 } else {
169 union register_pair rp __uninitialized;
170
171 rp.even = word;
172 asm("flogr %[rp],%[rp]"
173 : [rp] "+d" (rp.pair) : : "cc");
174 bit = rp.even;
175 /*
176 * The result of the flogr instruction is a value in the range
177 * of 0..64. Let the compiler know that the AND operation can
178 * be optimized away.
179 */
180 __assume(bit <= 64);
181 return bit & 127;
182 }
183}
184
185/**
186 * ffs - find first bit set
187 * @word: the word to search
188 *
189 * This is defined the same way as the libc and
190 * compiler builtin ffs routines (man ffs).
191 */
192static __always_inline __flatten __attribute_const__ int ffs(int word)
193{
194 unsigned int val = (unsigned int)word;
195
196 return BITS_PER_LONG - __flogr(-val & val);
197}
198
199#else /* CONFIG_CC_HAS_BUILTIN_FFS */
200
201#include <asm-generic/bitops/builtin-ffs.h>
202
203#endif /* CONFIG_CC_HAS_BUILTIN_FFS */
204
205#include <asm-generic/bitops/builtin-__ffs.h>
206#include <asm-generic/bitops/ffz.h>
207#include <asm-generic/bitops/builtin-__fls.h>
208#include <asm-generic/bitops/builtin-fls.h>
209#include <asm-generic/bitops/fls64.h>
210#include <asm/arch_hweight.h>
211#include <asm-generic/bitops/const_hweight.h>
212#include <asm-generic/bitops/sched.h>
213#include <asm-generic/bitops/le.h>
214#include <asm-generic/bitops/ext2-atomic-setbit.h>
215
216#endif /* _S390_BITOPS_H */
217

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source code of linux/arch/s390/include/asm/bitops.h