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/atomic_ops.h>
40 #include <asm/barrier.h>
41
42 #define __BITOPS_WORDS(bits) (((bits) + BITS_PER_LONG - 1) / BITS_PER_LONG)
43
44 static inline unsigned long *
45 __bitops_word(unsigned long nr, const volatile unsigned long *ptr)
46 {
47 unsigned long addr;
48
49 addr = (unsigned long)ptr + ((nr ^ (nr & (BITS_PER_LONG - 1))) >> 3);
50 return (unsigned long *)addr;
51 }
52
53 static inline unsigned long __bitops_mask(unsigned long nr)
54 {
55 return 1UL << (nr & (BITS_PER_LONG - 1));
56 }
57
58 static __always_inline void arch_set_bit(unsigned long nr, volatile unsigned long *ptr)
59 {
60 unsigned long *addr = __bitops_word(nr, ptr);
61 unsigned long mask = __bitops_mask(nr);
62
63 __atomic64_or(mask, (long *)addr);
64 }
65
66 static __always_inline void arch_clear_bit(unsigned long nr, volatile unsigned long *ptr)
67 {
68 unsigned long *addr = __bitops_word(nr, ptr);
69 unsigned long mask = __bitops_mask(nr);
70
71 __atomic64_and(~mask, (long *)addr);
72 }
73
74 static __always_inline void arch_change_bit(unsigned long nr,
75 volatile unsigned long *ptr)
76 {
77 unsigned long *addr = __bitops_word(nr, ptr);
78 unsigned long mask = __bitops_mask(nr);
79
80 __atomic64_xor(mask, (long *)addr);
81 }
82
83 static inline bool arch_test_and_set_bit(unsigned long nr,
84 volatile unsigned long *ptr)
85 {
86 unsigned long *addr = __bitops_word(nr, ptr);
87 unsigned long mask = __bitops_mask(nr);
88 unsigned long old;
89
90 old = __atomic64_or_barrier(mask, (long *)addr);
91 return old & mask;
92 }
93
94 static inline bool arch_test_and_clear_bit(unsigned long nr,
95 volatile unsigned long *ptr)
96 {
97 unsigned long *addr = __bitops_word(nr, ptr);
98 unsigned long mask = __bitops_mask(nr);
99 unsigned long old;
100
101 old = __atomic64_and_barrier(~mask, (long *)addr);
102 return old & mask;
103 }
104
105 static inline bool arch_test_and_change_bit(unsigned long nr,
106 volatile unsigned long *ptr)
107 {
108 unsigned long *addr = __bitops_word(nr, ptr);
109 unsigned long mask = __bitops_mask(nr);
110 unsigned long old;
111
112 old = __atomic64_xor_barrier(mask, (long *)addr);
113 return old & mask;
114 }
115
116 static __always_inline void
117 arch___set_bit(unsigned long nr, volatile unsigned long *addr)
118 {
119 unsigned long *p = __bitops_word(nr, addr);
120 unsigned long mask = __bitops_mask(nr);
121
122 *p |= mask;
123 }
124
125 static __always_inline void
126 arch___clear_bit(unsigned long nr, volatile unsigned long *addr)
127 {
128 unsigned long *p = __bitops_word(nr, addr);
129 unsigned long mask = __bitops_mask(nr);
130
131 *p &= ~mask;
132 }
133
134 static __always_inline void
135 arch___change_bit(unsigned long nr, volatile unsigned long *addr)
136 {
137 unsigned long *p = __bitops_word(nr, addr);
138 unsigned long mask = __bitops_mask(nr);
139
140 *p ^= mask;
141 }
142
143 static __always_inline bool
144 arch___test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
145 {
146 unsigned long *p = __bitops_word(nr, addr);
147 unsigned long mask = __bitops_mask(nr);
148 unsigned long old;
149
150 old = *p;
151 *p |= mask;
152 return old & mask;
153 }
154
155 static __always_inline bool
156 arch___test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
157 {
158 unsigned long *p = __bitops_word(nr, addr);
159 unsigned long mask = __bitops_mask(nr);
160 unsigned long old;
161
162 old = *p;
163 *p &= ~mask;
164 return old & mask;
165 }
166
167 static __always_inline bool
168 arch___test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
169 {
170 unsigned long *p = __bitops_word(nr, addr);
171 unsigned long mask = __bitops_mask(nr);
172 unsigned long old;
173
174 old = *p;
175 *p ^= mask;
176 return old & mask;
177 }
178
179 #define arch_test_bit generic_test_bit
180 #define arch_test_bit_acquire generic_test_bit_acquire
181
182 static inline bool arch_test_and_set_bit_lock(unsigned long nr,
183 volatile unsigned long *ptr)
184 {
185 if (arch_test_bit(nr, ptr))
186 return true;
187 return arch_test_and_set_bit(nr, ptr);
188 }
189
190 static inline void arch_clear_bit_unlock(unsigned long nr,
191 volatile unsigned long *ptr)
192 {
193 smp_mb__before_atomic();
194 arch_clear_bit(nr, ptr);
195 }
196
197 static inline void arch___clear_bit_unlock(unsigned long nr,
198 volatile unsigned long *ptr)
199 {
200 smp_mb();
201 arch___clear_bit(nr, ptr);
202 }
203
204 static inline bool arch_xor_unlock_is_negative_byte(unsigned long mask,
205 volatile unsigned long *ptr)
206 {
207 unsigned long old;
208
209 old = __atomic64_xor_barrier(mask, (long *)ptr);
210 return old & BIT(7);
211 }
212 #define arch_xor_unlock_is_negative_byte arch_xor_unlock_is_negative_byte
213
214 #include <asm-generic/bitops/instrumented-atomic.h>
215 #include <asm-generic/bitops/instrumented-non-atomic.h>
216 #include <asm-generic/bitops/instrumented-lock.h>
217
218 /*
219 * Functions which use MSB0 bit numbering.
220 * The bits are numbered:
221 * |0..............63|64............127|128...........191|192...........255|
222 */
223 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
224 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
225 unsigned long offset);
226
227 #define for_each_set_bit_inv(bit, addr, size) \
228 for ((bit) = find_first_bit_inv((addr), (size)); \
229 (bit) < (size); \
230 (bit) = find_next_bit_inv((addr), (size), (bit) + 1))
231
232 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
233 {
234 return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
235 }
236
237 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
238 {
239 return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
240 }
241
242 static inline bool test_and_clear_bit_inv(unsigned long nr,
243 volatile unsigned long *ptr)
244 {
245 return test_and_clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
246 }
247
248 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
249 {
250 return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
251 }
252
253 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
254 {
255 return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
256 }
257
258 static inline bool test_bit_inv(unsigned long nr,
259 const volatile unsigned long *ptr)
260 {
261 return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
262 }
263
264 /**
265 * __flogr - find leftmost one
266 * @word - The word to search
267 *
268 * Returns the bit number of the most significant bit set,
269 * where the most significant bit has bit number 0.
270 * If no bit is set this function returns 64.
271 */
272 static inline unsigned char __flogr(unsigned long word)
273 {
274 if (__builtin_constant_p(word)) {
275 unsigned long bit = 0;
276
277 if (!word)
278 return 64;
279 if (!(word & 0xffffffff00000000UL)) {
280 word <<= 32;
281 bit += 32;
282 }
283 if (!(word & 0xffff000000000000UL)) {
284 word <<= 16;
285 bit += 16;
286 }
287 if (!(word & 0xff00000000000000UL)) {
288 word <<= 8;
289 bit += 8;
290 }
291 if (!(word & 0xf000000000000000UL)) {
292 word <<= 4;
293 bit += 4;
294 }
295 if (!(word & 0xc000000000000000UL)) {
296 word <<= 2;
297 bit += 2;
298 }
299 if (!(word & 0x8000000000000000UL)) {
300 word <<= 1;
301 bit += 1;
302 }
303 return bit;
304 } else {
305 union register_pair rp;
306
307 rp.even = word;
308 asm volatile(
309 " flogr %[rp],%[rp]\n"
310 : [rp] "+d" (rp.pair) : : "cc");
311 return rp.even;
312 }
313 }
314
315 /**
316 * __ffs - find first bit in word.
317 * @word: The word to search
318 *
319 * Undefined if no bit exists, so code should check against 0 first.
320 */
321 static inline unsigned long __ffs(unsigned long word)
322 {
323 return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
324 }
325
326 /**
327 * ffs - find first bit set
328 * @word: the word to search
329 *
330 * This is defined the same way as the libc and
331 * compiler builtin ffs routines (man ffs).
332 */
333 static inline int ffs(int word)
334 {
335 unsigned long mask = 2 * BITS_PER_LONG - 1;
336 unsigned int val = (unsigned int)word;
337
338 return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
339 }
340
341 /**
342 * __fls - find last (most-significant) set bit in a long word
343 * @word: the word to search
344 *
345 * Undefined if no set bit exists, so code should check against 0 first.
346 */
347 static inline unsigned long __fls(unsigned long word)
348 {
349 return __flogr(word) ^ (BITS_PER_LONG - 1);
350 }
351
352 /**
353 * fls64 - find last set bit in a 64-bit word
354 * @word: the word to search
355 *
356 * This is defined in a similar way as the libc and compiler builtin
357 * ffsll, but returns the position of the most significant set bit.
358 *
359 * fls64(value) returns 0 if value is 0 or the position of the last
360 * set bit if value is nonzero. The last (most significant) bit is
361 * at position 64.
362 */
363 static inline int fls64(unsigned long word)
364 {
365 unsigned long mask = 2 * BITS_PER_LONG - 1;
366
367 return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
368 }
369
370 /**
371 * fls - find last (most-significant) bit set
372 * @word: the word to search
373 *
374 * This is defined the same way as ffs.
375 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
376 */
377 static inline int fls(unsigned int word)
378 {
379 return fls64(word);
380 }
381
382 #include <asm/arch_hweight.h>
383 #include <asm-generic/bitops/const_hweight.h>
384 #include <asm-generic/bitops/ffz.h>
385 #include <asm-generic/bitops/sched.h>
386 #include <asm-generic/bitops/le.h>
387 #include <asm-generic/bitops/ext2-atomic-setbit.h>
388
389 #endif /* _S390_BITOPS_H */
390
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