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
44static 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
53static inline unsigned long __bitops_mask(unsigned long nr)
54{
55	return 1UL << (nr & (BITS_PER_LONG - 1));
56}
57
58static __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
66static __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
74static __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
83static 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
94static 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
105static 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
116static __always_inline void
117arch___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
125static __always_inline void
126arch___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
134static __always_inline void
135arch___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
143static __always_inline bool
144arch___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
155static __always_inline bool
156arch___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
167static __always_inline bool
168arch___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
182static 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
190static 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
197static 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
204static 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 */
223unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
224unsigned 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
232static 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
237static 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
242static 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
248static 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
253static 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
258static 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 */
272static 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 */
321static 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 */
333static 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 */
347static 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 */
363static 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 */
377static inline int fls(unsigned int word)
378{
379	return fls64(word);
380}
381
382#include <asm-generic/bitops/ffz.h>
383#include <asm-generic/bitops/hweight.h>
384#include <asm-generic/bitops/sched.h>
385#include <asm-generic/bitops/le.h>
386#include <asm-generic/bitops/ext2-atomic-setbit.h>
387
388#endif /* _S390_BITOPS_H */
389