xref: /openbmc/linux/arch/s390/include/asm/bitops.h (revision d3964221)
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 void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
265 {
266 	return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
267 }
268 
269 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
270 {
271 	return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
272 }
273 
274 static inline int test_bit_inv(unsigned long nr,
275 			       const volatile unsigned long *ptr)
276 {
277 	return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
278 }
279 
280 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
281 
282 /**
283  * __flogr - find leftmost one
284  * @word - The word to search
285  *
286  * Returns the bit number of the most significant bit set,
287  * where the most significant bit has bit number 0.
288  * If no bit is set this function returns 64.
289  */
290 static inline unsigned char __flogr(unsigned long word)
291 {
292 	if (__builtin_constant_p(word)) {
293 		unsigned long bit = 0;
294 
295 		if (!word)
296 			return 64;
297 		if (!(word & 0xffffffff00000000UL)) {
298 			word <<= 32;
299 			bit += 32;
300 		}
301 		if (!(word & 0xffff000000000000UL)) {
302 			word <<= 16;
303 			bit += 16;
304 		}
305 		if (!(word & 0xff00000000000000UL)) {
306 			word <<= 8;
307 			bit += 8;
308 		}
309 		if (!(word & 0xf000000000000000UL)) {
310 			word <<= 4;
311 			bit += 4;
312 		}
313 		if (!(word & 0xc000000000000000UL)) {
314 			word <<= 2;
315 			bit += 2;
316 		}
317 		if (!(word & 0x8000000000000000UL)) {
318 			word <<= 1;
319 			bit += 1;
320 		}
321 		return bit;
322 	} else {
323 		register unsigned long bit asm("4") = word;
324 		register unsigned long out asm("5");
325 
326 		asm volatile(
327 			"       flogr   %[bit],%[bit]\n"
328 			: [bit] "+d" (bit), [out] "=d" (out) : : "cc");
329 		return bit;
330 	}
331 }
332 
333 /**
334  * __ffs - find first bit in word.
335  * @word: The word to search
336  *
337  * Undefined if no bit exists, so code should check against 0 first.
338  */
339 static inline unsigned long __ffs(unsigned long word)
340 {
341 	return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
342 }
343 
344 /**
345  * ffs - find first bit set
346  * @word: the word to search
347  *
348  * This is defined the same way as the libc and
349  * compiler builtin ffs routines (man ffs).
350  */
351 static inline int ffs(int word)
352 {
353 	unsigned long mask = 2 * BITS_PER_LONG - 1;
354 	unsigned int val = (unsigned int)word;
355 
356 	return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
357 }
358 
359 /**
360  * __fls - find last (most-significant) set bit in a long word
361  * @word: the word to search
362  *
363  * Undefined if no set bit exists, so code should check against 0 first.
364  */
365 static inline unsigned long __fls(unsigned long word)
366 {
367 	return __flogr(word) ^ (BITS_PER_LONG - 1);
368 }
369 
370 /**
371  * fls64 - find last set bit in a 64-bit word
372  * @word: the word to search
373  *
374  * This is defined in a similar way as the libc and compiler builtin
375  * ffsll, but returns the position of the most significant set bit.
376  *
377  * fls64(value) returns 0 if value is 0 or the position of the last
378  * set bit if value is nonzero. The last (most significant) bit is
379  * at position 64.
380  */
381 static inline int fls64(unsigned long word)
382 {
383 	unsigned long mask = 2 * BITS_PER_LONG - 1;
384 
385 	return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
386 }
387 
388 /**
389  * fls - find last (most-significant) bit set
390  * @word: the word to search
391  *
392  * This is defined the same way as ffs.
393  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
394  */
395 static inline int fls(int word)
396 {
397 	return fls64((unsigned int)word);
398 }
399 
400 #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
401 
402 #include <asm-generic/bitops/__ffs.h>
403 #include <asm-generic/bitops/ffs.h>
404 #include <asm-generic/bitops/__fls.h>
405 #include <asm-generic/bitops/fls.h>
406 #include <asm-generic/bitops/fls64.h>
407 
408 #endif /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
409 
410 #include <asm-generic/bitops/ffz.h>
411 #include <asm-generic/bitops/find.h>
412 #include <asm-generic/bitops/hweight.h>
413 #include <asm-generic/bitops/sched.h>
414 #include <asm-generic/bitops/le.h>
415 #include <asm-generic/bitops/ext2-atomic-setbit.h>
416 
417 #endif /* _S390_BITOPS_H */
418