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 *
__bitops_word(unsigned long nr,const volatile unsigned long * ptr)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 
__bitops_mask(unsigned long nr)53 static inline unsigned long __bitops_mask(unsigned long nr)
54 {
55 	return 1UL << (nr & (BITS_PER_LONG - 1));
56 }
57 
arch_set_bit(unsigned long nr,volatile unsigned long * ptr)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 
arch_clear_bit(unsigned long nr,volatile unsigned long * ptr)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 
arch_change_bit(unsigned long nr,volatile unsigned long * ptr)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 
arch_test_and_set_bit(unsigned long nr,volatile unsigned long * ptr)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 
arch_test_and_clear_bit(unsigned long nr,volatile unsigned long * ptr)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 
arch_test_and_change_bit(unsigned long nr,volatile unsigned long * ptr)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
arch___set_bit(unsigned long nr,volatile unsigned long * addr)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
arch___clear_bit(unsigned long nr,volatile unsigned long * addr)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
arch___change_bit(unsigned long nr,volatile unsigned long * addr)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
arch___test_and_set_bit(unsigned long nr,volatile unsigned long * addr)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
arch___test_and_clear_bit(unsigned long nr,volatile unsigned long * addr)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
arch___test_and_change_bit(unsigned long nr,volatile unsigned long * addr)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 
arch_test_and_set_bit_lock(unsigned long nr,volatile unsigned long * ptr)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 
arch_clear_bit_unlock(unsigned long nr,volatile unsigned long * ptr)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 
arch___clear_bit_unlock(unsigned long nr,volatile unsigned long * ptr)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 #include <asm-generic/bitops/instrumented-atomic.h>
205 #include <asm-generic/bitops/instrumented-non-atomic.h>
206 #include <asm-generic/bitops/instrumented-lock.h>
207 
208 /*
209  * Functions which use MSB0 bit numbering.
210  * The bits are numbered:
211  *   |0..............63|64............127|128...........191|192...........255|
212  */
213 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
214 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
215 				unsigned long offset);
216 
217 #define for_each_set_bit_inv(bit, addr, size)				\
218 	for ((bit) = find_first_bit_inv((addr), (size));		\
219 	     (bit) < (size);						\
220 	     (bit) = find_next_bit_inv((addr), (size), (bit) + 1))
221 
set_bit_inv(unsigned long nr,volatile unsigned long * ptr)222 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
223 {
224 	return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
225 }
226 
clear_bit_inv(unsigned long nr,volatile unsigned long * ptr)227 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
228 {
229 	return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
230 }
231 
test_and_clear_bit_inv(unsigned long nr,volatile unsigned long * ptr)232 static inline bool test_and_clear_bit_inv(unsigned long nr,
233 					  volatile unsigned long *ptr)
234 {
235 	return test_and_clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
236 }
237 
__set_bit_inv(unsigned long nr,volatile unsigned long * ptr)238 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
239 {
240 	return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
241 }
242 
__clear_bit_inv(unsigned long nr,volatile unsigned long * ptr)243 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
244 {
245 	return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
246 }
247 
test_bit_inv(unsigned long nr,const volatile unsigned long * ptr)248 static inline bool test_bit_inv(unsigned long nr,
249 				const volatile unsigned long *ptr)
250 {
251 	return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
252 }
253 
254 /**
255  * __flogr - find leftmost one
256  * @word - The word to search
257  *
258  * Returns the bit number of the most significant bit set,
259  * where the most significant bit has bit number 0.
260  * If no bit is set this function returns 64.
261  */
__flogr(unsigned long word)262 static inline unsigned char __flogr(unsigned long word)
263 {
264 	if (__builtin_constant_p(word)) {
265 		unsigned long bit = 0;
266 
267 		if (!word)
268 			return 64;
269 		if (!(word & 0xffffffff00000000UL)) {
270 			word <<= 32;
271 			bit += 32;
272 		}
273 		if (!(word & 0xffff000000000000UL)) {
274 			word <<= 16;
275 			bit += 16;
276 		}
277 		if (!(word & 0xff00000000000000UL)) {
278 			word <<= 8;
279 			bit += 8;
280 		}
281 		if (!(word & 0xf000000000000000UL)) {
282 			word <<= 4;
283 			bit += 4;
284 		}
285 		if (!(word & 0xc000000000000000UL)) {
286 			word <<= 2;
287 			bit += 2;
288 		}
289 		if (!(word & 0x8000000000000000UL)) {
290 			word <<= 1;
291 			bit += 1;
292 		}
293 		return bit;
294 	} else {
295 		union register_pair rp;
296 
297 		rp.even = word;
298 		asm volatile(
299 			"       flogr   %[rp],%[rp]\n"
300 			: [rp] "+d" (rp.pair) : : "cc");
301 		return rp.even;
302 	}
303 }
304 
305 /**
306  * __ffs - find first bit in word.
307  * @word: The word to search
308  *
309  * Undefined if no bit exists, so code should check against 0 first.
310  */
__ffs(unsigned long word)311 static inline unsigned long __ffs(unsigned long word)
312 {
313 	return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
314 }
315 
316 /**
317  * ffs - find first bit set
318  * @word: the word to search
319  *
320  * This is defined the same way as the libc and
321  * compiler builtin ffs routines (man ffs).
322  */
ffs(int word)323 static inline int ffs(int word)
324 {
325 	unsigned long mask = 2 * BITS_PER_LONG - 1;
326 	unsigned int val = (unsigned int)word;
327 
328 	return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
329 }
330 
331 /**
332  * __fls - find last (most-significant) set bit in a long word
333  * @word: the word to search
334  *
335  * Undefined if no set bit exists, so code should check against 0 first.
336  */
__fls(unsigned long word)337 static inline unsigned long __fls(unsigned long word)
338 {
339 	return __flogr(word) ^ (BITS_PER_LONG - 1);
340 }
341 
342 /**
343  * fls64 - find last set bit in a 64-bit word
344  * @word: the word to search
345  *
346  * This is defined in a similar way as the libc and compiler builtin
347  * ffsll, but returns the position of the most significant set bit.
348  *
349  * fls64(value) returns 0 if value is 0 or the position of the last
350  * set bit if value is nonzero. The last (most significant) bit is
351  * at position 64.
352  */
fls64(unsigned long word)353 static inline int fls64(unsigned long word)
354 {
355 	unsigned long mask = 2 * BITS_PER_LONG - 1;
356 
357 	return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
358 }
359 
360 /**
361  * fls - find last (most-significant) bit set
362  * @word: the word to search
363  *
364  * This is defined the same way as ffs.
365  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
366  */
fls(unsigned int word)367 static inline int fls(unsigned int word)
368 {
369 	return fls64(word);
370 }
371 
372 #include <asm-generic/bitops/ffz.h>
373 #include <asm-generic/bitops/hweight.h>
374 #include <asm-generic/bitops/sched.h>
375 #include <asm-generic/bitops/le.h>
376 #include <asm-generic/bitops/ext2-atomic-setbit.h>
377 
378 #endif /* _S390_BITOPS_H */
379