xref: /openbmc/linux/arch/s390/include/asm/bitops.h (revision e3b9f1e8)
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 <asm/atomic_ops.h>
39 #include <asm/barrier.h>
40 
41 #define __BITOPS_WORDS(bits) (((bits) + BITS_PER_LONG - 1) / BITS_PER_LONG)
42 
43 static inline unsigned long *
44 __bitops_word(unsigned long nr, volatile unsigned long *ptr)
45 {
46 	unsigned long addr;
47 
48 	addr = (unsigned long)ptr + ((nr ^ (nr & (BITS_PER_LONG - 1))) >> 3);
49 	return (unsigned long *)addr;
50 }
51 
52 static inline unsigned char *
53 __bitops_byte(unsigned long nr, volatile unsigned long *ptr)
54 {
55 	return ((unsigned char *)ptr) + ((nr ^ (BITS_PER_LONG - 8)) >> 3);
56 }
57 
58 static inline void set_bit(unsigned long nr, volatile unsigned long *ptr)
59 {
60 	unsigned long *addr = __bitops_word(nr, ptr);
61 	unsigned long mask;
62 
63 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
64 	if (__builtin_constant_p(nr)) {
65 		unsigned char *caddr = __bitops_byte(nr, ptr);
66 
67 		asm volatile(
68 			"oi	%0,%b1\n"
69 			: "+Q" (*caddr)
70 			: "i" (1 << (nr & 7))
71 			: "cc", "memory");
72 		return;
73 	}
74 #endif
75 	mask = 1UL << (nr & (BITS_PER_LONG - 1));
76 	__atomic64_or(mask, addr);
77 }
78 
79 static inline void clear_bit(unsigned long nr, volatile unsigned long *ptr)
80 {
81 	unsigned long *addr = __bitops_word(nr, ptr);
82 	unsigned long mask;
83 
84 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
85 	if (__builtin_constant_p(nr)) {
86 		unsigned char *caddr = __bitops_byte(nr, ptr);
87 
88 		asm volatile(
89 			"ni	%0,%b1\n"
90 			: "+Q" (*caddr)
91 			: "i" (~(1 << (nr & 7)))
92 			: "cc", "memory");
93 		return;
94 	}
95 #endif
96 	mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
97 	__atomic64_and(mask, addr);
98 }
99 
100 static inline void change_bit(unsigned long nr, volatile unsigned long *ptr)
101 {
102 	unsigned long *addr = __bitops_word(nr, ptr);
103 	unsigned long mask;
104 
105 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
106 	if (__builtin_constant_p(nr)) {
107 		unsigned char *caddr = __bitops_byte(nr, ptr);
108 
109 		asm volatile(
110 			"xi	%0,%b1\n"
111 			: "+Q" (*caddr)
112 			: "i" (1 << (nr & 7))
113 			: "cc", "memory");
114 		return;
115 	}
116 #endif
117 	mask = 1UL << (nr & (BITS_PER_LONG - 1));
118 	__atomic64_xor(mask, addr);
119 }
120 
121 static inline int
122 test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
123 {
124 	unsigned long *addr = __bitops_word(nr, ptr);
125 	unsigned long old, mask;
126 
127 	mask = 1UL << (nr & (BITS_PER_LONG - 1));
128 	old = __atomic64_or_barrier(mask, addr);
129 	return (old & mask) != 0;
130 }
131 
132 static inline int
133 test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
134 {
135 	unsigned long *addr = __bitops_word(nr, ptr);
136 	unsigned long old, mask;
137 
138 	mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
139 	old = __atomic64_and_barrier(mask, addr);
140 	return (old & ~mask) != 0;
141 }
142 
143 static inline int
144 test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
145 {
146 	unsigned long *addr = __bitops_word(nr, ptr);
147 	unsigned long old, mask;
148 
149 	mask = 1UL << (nr & (BITS_PER_LONG - 1));
150 	old = __atomic64_xor_barrier(mask, addr);
151 	return (old & mask) != 0;
152 }
153 
154 static inline void __set_bit(unsigned long nr, volatile unsigned long *ptr)
155 {
156 	unsigned char *addr = __bitops_byte(nr, ptr);
157 
158 	*addr |= 1 << (nr & 7);
159 }
160 
161 static inline void
162 __clear_bit(unsigned long nr, volatile unsigned long *ptr)
163 {
164 	unsigned char *addr = __bitops_byte(nr, ptr);
165 
166 	*addr &= ~(1 << (nr & 7));
167 }
168 
169 static inline void __change_bit(unsigned long nr, volatile unsigned long *ptr)
170 {
171 	unsigned char *addr = __bitops_byte(nr, ptr);
172 
173 	*addr ^= 1 << (nr & 7);
174 }
175 
176 static inline int
177 __test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
178 {
179 	unsigned char *addr = __bitops_byte(nr, ptr);
180 	unsigned char ch;
181 
182 	ch = *addr;
183 	*addr |= 1 << (nr & 7);
184 	return (ch >> (nr & 7)) & 1;
185 }
186 
187 static inline int
188 __test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
189 {
190 	unsigned char *addr = __bitops_byte(nr, ptr);
191 	unsigned char ch;
192 
193 	ch = *addr;
194 	*addr &= ~(1 << (nr & 7));
195 	return (ch >> (nr & 7)) & 1;
196 }
197 
198 static inline int
199 __test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
200 {
201 	unsigned char *addr = __bitops_byte(nr, ptr);
202 	unsigned char ch;
203 
204 	ch = *addr;
205 	*addr ^= 1 << (nr & 7);
206 	return (ch >> (nr & 7)) & 1;
207 }
208 
209 static inline int test_bit(unsigned long nr, const volatile unsigned long *ptr)
210 {
211 	const volatile unsigned char *addr;
212 
213 	addr = ((const volatile unsigned char *)ptr);
214 	addr += (nr ^ (BITS_PER_LONG - 8)) >> 3;
215 	return (*addr >> (nr & 7)) & 1;
216 }
217 
218 static inline int test_and_set_bit_lock(unsigned long nr,
219 					volatile unsigned long *ptr)
220 {
221 	if (test_bit(nr, ptr))
222 		return 1;
223 	return test_and_set_bit(nr, ptr);
224 }
225 
226 static inline void clear_bit_unlock(unsigned long nr,
227 				    volatile unsigned long *ptr)
228 {
229 	smp_mb__before_atomic();
230 	clear_bit(nr, ptr);
231 }
232 
233 static inline void __clear_bit_unlock(unsigned long nr,
234 				      volatile unsigned long *ptr)
235 {
236 	smp_mb();
237 	__clear_bit(nr, ptr);
238 }
239 
240 /*
241  * Functions which use MSB0 bit numbering.
242  * The bits are numbered:
243  *   |0..............63|64............127|128...........191|192...........255|
244  */
245 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
246 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
247 				unsigned long offset);
248 
249 #define for_each_set_bit_inv(bit, addr, size)				\
250 	for ((bit) = find_first_bit_inv((addr), (size));		\
251 	     (bit) < (size);						\
252 	     (bit) = find_next_bit_inv((addr), (size), (bit) + 1))
253 
254 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
255 {
256 	return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
257 }
258 
259 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
260 {
261 	return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
262 }
263 
264 static inline int test_and_clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
265 {
266 	return test_and_clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
267 }
268 
269 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
270 {
271 	return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
272 }
273 
274 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
275 {
276 	return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
277 }
278 
279 static inline int test_bit_inv(unsigned long nr,
280 			       const volatile unsigned long *ptr)
281 {
282 	return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
283 }
284 
285 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
286 
287 /**
288  * __flogr - find leftmost one
289  * @word - The word to search
290  *
291  * Returns the bit number of the most significant bit set,
292  * where the most significant bit has bit number 0.
293  * If no bit is set this function returns 64.
294  */
295 static inline unsigned char __flogr(unsigned long word)
296 {
297 	if (__builtin_constant_p(word)) {
298 		unsigned long bit = 0;
299 
300 		if (!word)
301 			return 64;
302 		if (!(word & 0xffffffff00000000UL)) {
303 			word <<= 32;
304 			bit += 32;
305 		}
306 		if (!(word & 0xffff000000000000UL)) {
307 			word <<= 16;
308 			bit += 16;
309 		}
310 		if (!(word & 0xff00000000000000UL)) {
311 			word <<= 8;
312 			bit += 8;
313 		}
314 		if (!(word & 0xf000000000000000UL)) {
315 			word <<= 4;
316 			bit += 4;
317 		}
318 		if (!(word & 0xc000000000000000UL)) {
319 			word <<= 2;
320 			bit += 2;
321 		}
322 		if (!(word & 0x8000000000000000UL)) {
323 			word <<= 1;
324 			bit += 1;
325 		}
326 		return bit;
327 	} else {
328 		register unsigned long bit asm("4") = word;
329 		register unsigned long out asm("5");
330 
331 		asm volatile(
332 			"       flogr   %[bit],%[bit]\n"
333 			: [bit] "+d" (bit), [out] "=d" (out) : : "cc");
334 		return bit;
335 	}
336 }
337 
338 /**
339  * __ffs - find first bit in word.
340  * @word: The word to search
341  *
342  * Undefined if no bit exists, so code should check against 0 first.
343  */
344 static inline unsigned long __ffs(unsigned long word)
345 {
346 	return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
347 }
348 
349 /**
350  * ffs - find first bit set
351  * @word: the word to search
352  *
353  * This is defined the same way as the libc and
354  * compiler builtin ffs routines (man ffs).
355  */
356 static inline int ffs(int word)
357 {
358 	unsigned long mask = 2 * BITS_PER_LONG - 1;
359 	unsigned int val = (unsigned int)word;
360 
361 	return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
362 }
363 
364 /**
365  * __fls - find last (most-significant) set bit in a long word
366  * @word: the word to search
367  *
368  * Undefined if no set bit exists, so code should check against 0 first.
369  */
370 static inline unsigned long __fls(unsigned long word)
371 {
372 	return __flogr(word) ^ (BITS_PER_LONG - 1);
373 }
374 
375 /**
376  * fls64 - find last set bit in a 64-bit word
377  * @word: the word to search
378  *
379  * This is defined in a similar way as the libc and compiler builtin
380  * ffsll, but returns the position of the most significant set bit.
381  *
382  * fls64(value) returns 0 if value is 0 or the position of the last
383  * set bit if value is nonzero. The last (most significant) bit is
384  * at position 64.
385  */
386 static inline int fls64(unsigned long word)
387 {
388 	unsigned long mask = 2 * BITS_PER_LONG - 1;
389 
390 	return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
391 }
392 
393 /**
394  * fls - find last (most-significant) bit set
395  * @word: the word to search
396  *
397  * This is defined the same way as ffs.
398  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
399  */
400 static inline int fls(int word)
401 {
402 	return fls64((unsigned int)word);
403 }
404 
405 #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
406 
407 #include <asm-generic/bitops/__ffs.h>
408 #include <asm-generic/bitops/ffs.h>
409 #include <asm-generic/bitops/__fls.h>
410 #include <asm-generic/bitops/fls.h>
411 #include <asm-generic/bitops/fls64.h>
412 
413 #endif /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
414 
415 #include <asm-generic/bitops/ffz.h>
416 #include <asm-generic/bitops/find.h>
417 #include <asm-generic/bitops/hweight.h>
418 #include <asm-generic/bitops/sched.h>
419 #include <asm-generic/bitops/le.h>
420 #include <asm-generic/bitops/ext2-atomic-setbit.h>
421 
422 #endif /* _S390_BITOPS_H */
423