xref: /openbmc/linux/arch/mips/include/asm/bitops.h (revision 8684014d)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (c) 1994 - 1997, 99, 2000, 06, 07  Ralf Baechle (ralf@linux-mips.org)
7  * Copyright (c) 1999, 2000  Silicon Graphics, Inc.
8  */
9 #ifndef _ASM_BITOPS_H
10 #define _ASM_BITOPS_H
11 
12 #ifndef _LINUX_BITOPS_H
13 #error only <linux/bitops.h> can be included directly
14 #endif
15 
16 #include <linux/compiler.h>
17 #include <linux/types.h>
18 #include <asm/barrier.h>
19 #include <asm/byteorder.h>		/* sigh ... */
20 #include <asm/compiler.h>
21 #include <asm/cpu-features.h>
22 #include <asm/sgidefs.h>
23 #include <asm/war.h>
24 
25 #if _MIPS_SZLONG == 32
26 #define SZLONG_LOG 5
27 #define SZLONG_MASK 31UL
28 #define __LL		"ll	"
29 #define __SC		"sc	"
30 #define __INS		"ins	"
31 #define __EXT		"ext	"
32 #elif _MIPS_SZLONG == 64
33 #define SZLONG_LOG 6
34 #define SZLONG_MASK 63UL
35 #define __LL		"lld	"
36 #define __SC		"scd	"
37 #define __INS		"dins	 "
38 #define __EXT		"dext	 "
39 #endif
40 
41 /*
42  * These are the "slower" versions of the functions and are in bitops.c.
43  * These functions call raw_local_irq_{save,restore}().
44  */
45 void __mips_set_bit(unsigned long nr, volatile unsigned long *addr);
46 void __mips_clear_bit(unsigned long nr, volatile unsigned long *addr);
47 void __mips_change_bit(unsigned long nr, volatile unsigned long *addr);
48 int __mips_test_and_set_bit(unsigned long nr,
49 			    volatile unsigned long *addr);
50 int __mips_test_and_set_bit_lock(unsigned long nr,
51 				 volatile unsigned long *addr);
52 int __mips_test_and_clear_bit(unsigned long nr,
53 			      volatile unsigned long *addr);
54 int __mips_test_and_change_bit(unsigned long nr,
55 			       volatile unsigned long *addr);
56 
57 
58 /*
59  * set_bit - Atomically set a bit in memory
60  * @nr: the bit to set
61  * @addr: the address to start counting from
62  *
63  * This function is atomic and may not be reordered.  See __set_bit()
64  * if you do not require the atomic guarantees.
65  * Note that @nr may be almost arbitrarily large; this function is not
66  * restricted to acting on a single-word quantity.
67  */
68 static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
69 {
70 	unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
71 	int bit = nr & SZLONG_MASK;
72 	unsigned long temp;
73 
74 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
75 		__asm__ __volatile__(
76 		"	.set	arch=r4000				\n"
77 		"1:	" __LL "%0, %1			# set_bit	\n"
78 		"	or	%0, %2					\n"
79 		"	" __SC	"%0, %1					\n"
80 		"	beqzl	%0, 1b					\n"
81 		"	.set	mips0					\n"
82 		: "=&r" (temp), "=" GCC_OFF12_ASM() (*m)
83 		: "ir" (1UL << bit), GCC_OFF12_ASM() (*m));
84 #ifdef CONFIG_CPU_MIPSR2
85 	} else if (kernel_uses_llsc && __builtin_constant_p(bit)) {
86 		do {
87 			__asm__ __volatile__(
88 			"	" __LL "%0, %1		# set_bit	\n"
89 			"	" __INS "%0, %3, %2, 1			\n"
90 			"	" __SC "%0, %1				\n"
91 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m)
92 			: "ir" (bit), "r" (~0));
93 		} while (unlikely(!temp));
94 #endif /* CONFIG_CPU_MIPSR2 */
95 	} else if (kernel_uses_llsc) {
96 		do {
97 			__asm__ __volatile__(
98 			"	.set	arch=r4000			\n"
99 			"	" __LL "%0, %1		# set_bit	\n"
100 			"	or	%0, %2				\n"
101 			"	" __SC	"%0, %1				\n"
102 			"	.set	mips0				\n"
103 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m)
104 			: "ir" (1UL << bit));
105 		} while (unlikely(!temp));
106 	} else
107 		__mips_set_bit(nr, addr);
108 }
109 
110 /*
111  * clear_bit - Clears a bit in memory
112  * @nr: Bit to clear
113  * @addr: Address to start counting from
114  *
115  * clear_bit() is atomic and may not be reordered.  However, it does
116  * not contain a memory barrier, so if it is used for locking purposes,
117  * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
118  * in order to ensure changes are visible on other processors.
119  */
120 static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
121 {
122 	unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
123 	int bit = nr & SZLONG_MASK;
124 	unsigned long temp;
125 
126 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
127 		__asm__ __volatile__(
128 		"	.set	arch=r4000				\n"
129 		"1:	" __LL "%0, %1			# clear_bit	\n"
130 		"	and	%0, %2					\n"
131 		"	" __SC "%0, %1					\n"
132 		"	beqzl	%0, 1b					\n"
133 		"	.set	mips0					\n"
134 		: "=&r" (temp), "+" GCC_OFF12_ASM() (*m)
135 		: "ir" (~(1UL << bit)));
136 #ifdef CONFIG_CPU_MIPSR2
137 	} else if (kernel_uses_llsc && __builtin_constant_p(bit)) {
138 		do {
139 			__asm__ __volatile__(
140 			"	" __LL "%0, %1		# clear_bit	\n"
141 			"	" __INS "%0, $0, %2, 1			\n"
142 			"	" __SC "%0, %1				\n"
143 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m)
144 			: "ir" (bit));
145 		} while (unlikely(!temp));
146 #endif /* CONFIG_CPU_MIPSR2 */
147 	} else if (kernel_uses_llsc) {
148 		do {
149 			__asm__ __volatile__(
150 			"	.set	arch=r4000			\n"
151 			"	" __LL "%0, %1		# clear_bit	\n"
152 			"	and	%0, %2				\n"
153 			"	" __SC "%0, %1				\n"
154 			"	.set	mips0				\n"
155 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m)
156 			: "ir" (~(1UL << bit)));
157 		} while (unlikely(!temp));
158 	} else
159 		__mips_clear_bit(nr, addr);
160 }
161 
162 /*
163  * clear_bit_unlock - Clears a bit in memory
164  * @nr: Bit to clear
165  * @addr: Address to start counting from
166  *
167  * clear_bit() is atomic and implies release semantics before the memory
168  * operation. It can be used for an unlock.
169  */
170 static inline void clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
171 {
172 	smp_mb__before_atomic();
173 	clear_bit(nr, addr);
174 }
175 
176 /*
177  * change_bit - Toggle a bit in memory
178  * @nr: Bit to change
179  * @addr: Address to start counting from
180  *
181  * change_bit() is atomic and may not be reordered.
182  * Note that @nr may be almost arbitrarily large; this function is not
183  * restricted to acting on a single-word quantity.
184  */
185 static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
186 {
187 	int bit = nr & SZLONG_MASK;
188 
189 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
190 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
191 		unsigned long temp;
192 
193 		__asm__ __volatile__(
194 		"	.set	arch=r4000			\n"
195 		"1:	" __LL "%0, %1		# change_bit	\n"
196 		"	xor	%0, %2				\n"
197 		"	" __SC	"%0, %1				\n"
198 		"	beqzl	%0, 1b				\n"
199 		"	.set	mips0				\n"
200 		: "=&r" (temp), "+" GCC_OFF12_ASM() (*m)
201 		: "ir" (1UL << bit));
202 	} else if (kernel_uses_llsc) {
203 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
204 		unsigned long temp;
205 
206 		do {
207 			__asm__ __volatile__(
208 			"	.set	arch=r4000			\n"
209 			"	" __LL "%0, %1		# change_bit	\n"
210 			"	xor	%0, %2				\n"
211 			"	" __SC	"%0, %1				\n"
212 			"	.set	mips0				\n"
213 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m)
214 			: "ir" (1UL << bit));
215 		} while (unlikely(!temp));
216 	} else
217 		__mips_change_bit(nr, addr);
218 }
219 
220 /*
221  * test_and_set_bit - Set a bit and return its old value
222  * @nr: Bit to set
223  * @addr: Address to count from
224  *
225  * This operation is atomic and cannot be reordered.
226  * It also implies a memory barrier.
227  */
228 static inline int test_and_set_bit(unsigned long nr,
229 	volatile unsigned long *addr)
230 {
231 	int bit = nr & SZLONG_MASK;
232 	unsigned long res;
233 
234 	smp_mb__before_llsc();
235 
236 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
237 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
238 		unsigned long temp;
239 
240 		__asm__ __volatile__(
241 		"	.set	arch=r4000				\n"
242 		"1:	" __LL "%0, %1		# test_and_set_bit	\n"
243 		"	or	%2, %0, %3				\n"
244 		"	" __SC	"%2, %1					\n"
245 		"	beqzl	%2, 1b					\n"
246 		"	and	%2, %0, %3				\n"
247 		"	.set	mips0					\n"
248 		: "=&r" (temp), "+" GCC_OFF12_ASM() (*m), "=&r" (res)
249 		: "r" (1UL << bit)
250 		: "memory");
251 	} else if (kernel_uses_llsc) {
252 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
253 		unsigned long temp;
254 
255 		do {
256 			__asm__ __volatile__(
257 			"	.set	arch=r4000			\n"
258 			"	" __LL "%0, %1	# test_and_set_bit	\n"
259 			"	or	%2, %0, %3			\n"
260 			"	" __SC	"%2, %1				\n"
261 			"	.set	mips0				\n"
262 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m), "=&r" (res)
263 			: "r" (1UL << bit)
264 			: "memory");
265 		} while (unlikely(!res));
266 
267 		res = temp & (1UL << bit);
268 	} else
269 		res = __mips_test_and_set_bit(nr, addr);
270 
271 	smp_llsc_mb();
272 
273 	return res != 0;
274 }
275 
276 /*
277  * test_and_set_bit_lock - Set a bit and return its old value
278  * @nr: Bit to set
279  * @addr: Address to count from
280  *
281  * This operation is atomic and implies acquire ordering semantics
282  * after the memory operation.
283  */
284 static inline int test_and_set_bit_lock(unsigned long nr,
285 	volatile unsigned long *addr)
286 {
287 	int bit = nr & SZLONG_MASK;
288 	unsigned long res;
289 
290 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
291 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
292 		unsigned long temp;
293 
294 		__asm__ __volatile__(
295 		"	.set	arch=r4000				\n"
296 		"1:	" __LL "%0, %1		# test_and_set_bit	\n"
297 		"	or	%2, %0, %3				\n"
298 		"	" __SC	"%2, %1					\n"
299 		"	beqzl	%2, 1b					\n"
300 		"	and	%2, %0, %3				\n"
301 		"	.set	mips0					\n"
302 		: "=&r" (temp), "+m" (*m), "=&r" (res)
303 		: "r" (1UL << bit)
304 		: "memory");
305 	} else if (kernel_uses_llsc) {
306 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
307 		unsigned long temp;
308 
309 		do {
310 			__asm__ __volatile__(
311 			"	.set	arch=r4000			\n"
312 			"	" __LL "%0, %1	# test_and_set_bit	\n"
313 			"	or	%2, %0, %3			\n"
314 			"	" __SC	"%2, %1				\n"
315 			"	.set	mips0				\n"
316 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m), "=&r" (res)
317 			: "r" (1UL << bit)
318 			: "memory");
319 		} while (unlikely(!res));
320 
321 		res = temp & (1UL << bit);
322 	} else
323 		res = __mips_test_and_set_bit_lock(nr, addr);
324 
325 	smp_llsc_mb();
326 
327 	return res != 0;
328 }
329 /*
330  * test_and_clear_bit - Clear a bit and return its old value
331  * @nr: Bit to clear
332  * @addr: Address to count from
333  *
334  * This operation is atomic and cannot be reordered.
335  * It also implies a memory barrier.
336  */
337 static inline int test_and_clear_bit(unsigned long nr,
338 	volatile unsigned long *addr)
339 {
340 	int bit = nr & SZLONG_MASK;
341 	unsigned long res;
342 
343 	smp_mb__before_llsc();
344 
345 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
346 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
347 		unsigned long temp;
348 
349 		__asm__ __volatile__(
350 		"	.set	arch=r4000				\n"
351 		"1:	" __LL	"%0, %1		# test_and_clear_bit	\n"
352 		"	or	%2, %0, %3				\n"
353 		"	xor	%2, %3					\n"
354 		"	" __SC	"%2, %1					\n"
355 		"	beqzl	%2, 1b					\n"
356 		"	and	%2, %0, %3				\n"
357 		"	.set	mips0					\n"
358 		: "=&r" (temp), "+" GCC_OFF12_ASM() (*m), "=&r" (res)
359 		: "r" (1UL << bit)
360 		: "memory");
361 #ifdef CONFIG_CPU_MIPSR2
362 	} else if (kernel_uses_llsc && __builtin_constant_p(nr)) {
363 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
364 		unsigned long temp;
365 
366 		do {
367 			__asm__ __volatile__(
368 			"	" __LL	"%0, %1 # test_and_clear_bit	\n"
369 			"	" __EXT "%2, %0, %3, 1			\n"
370 			"	" __INS "%0, $0, %3, 1			\n"
371 			"	" __SC	"%0, %1				\n"
372 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m), "=&r" (res)
373 			: "ir" (bit)
374 			: "memory");
375 		} while (unlikely(!temp));
376 #endif
377 	} else if (kernel_uses_llsc) {
378 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
379 		unsigned long temp;
380 
381 		do {
382 			__asm__ __volatile__(
383 			"	.set	arch=r4000			\n"
384 			"	" __LL	"%0, %1 # test_and_clear_bit	\n"
385 			"	or	%2, %0, %3			\n"
386 			"	xor	%2, %3				\n"
387 			"	" __SC	"%2, %1				\n"
388 			"	.set	mips0				\n"
389 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m), "=&r" (res)
390 			: "r" (1UL << bit)
391 			: "memory");
392 		} while (unlikely(!res));
393 
394 		res = temp & (1UL << bit);
395 	} else
396 		res = __mips_test_and_clear_bit(nr, addr);
397 
398 	smp_llsc_mb();
399 
400 	return res != 0;
401 }
402 
403 /*
404  * test_and_change_bit - Change a bit and return its old value
405  * @nr: Bit to change
406  * @addr: Address to count from
407  *
408  * This operation is atomic and cannot be reordered.
409  * It also implies a memory barrier.
410  */
411 static inline int test_and_change_bit(unsigned long nr,
412 	volatile unsigned long *addr)
413 {
414 	int bit = nr & SZLONG_MASK;
415 	unsigned long res;
416 
417 	smp_mb__before_llsc();
418 
419 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
420 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
421 		unsigned long temp;
422 
423 		__asm__ __volatile__(
424 		"	.set	arch=r4000				\n"
425 		"1:	" __LL	"%0, %1		# test_and_change_bit	\n"
426 		"	xor	%2, %0, %3				\n"
427 		"	" __SC	"%2, %1					\n"
428 		"	beqzl	%2, 1b					\n"
429 		"	and	%2, %0, %3				\n"
430 		"	.set	mips0					\n"
431 		: "=&r" (temp), "+" GCC_OFF12_ASM() (*m), "=&r" (res)
432 		: "r" (1UL << bit)
433 		: "memory");
434 	} else if (kernel_uses_llsc) {
435 		unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
436 		unsigned long temp;
437 
438 		do {
439 			__asm__ __volatile__(
440 			"	.set	arch=r4000			\n"
441 			"	" __LL	"%0, %1 # test_and_change_bit	\n"
442 			"	xor	%2, %0, %3			\n"
443 			"	" __SC	"\t%2, %1			\n"
444 			"	.set	mips0				\n"
445 			: "=&r" (temp), "+" GCC_OFF12_ASM() (*m), "=&r" (res)
446 			: "r" (1UL << bit)
447 			: "memory");
448 		} while (unlikely(!res));
449 
450 		res = temp & (1UL << bit);
451 	} else
452 		res = __mips_test_and_change_bit(nr, addr);
453 
454 	smp_llsc_mb();
455 
456 	return res != 0;
457 }
458 
459 #include <asm-generic/bitops/non-atomic.h>
460 
461 /*
462  * __clear_bit_unlock - Clears a bit in memory
463  * @nr: Bit to clear
464  * @addr: Address to start counting from
465  *
466  * __clear_bit() is non-atomic and implies release semantics before the memory
467  * operation. It can be used for an unlock if no other CPUs can concurrently
468  * modify other bits in the word.
469  */
470 static inline void __clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
471 {
472 	smp_mb();
473 	__clear_bit(nr, addr);
474 }
475 
476 /*
477  * Return the bit position (0..63) of the most significant 1 bit in a word
478  * Returns -1 if no 1 bit exists
479  */
480 static inline unsigned long __fls(unsigned long word)
481 {
482 	int num;
483 
484 	if (BITS_PER_LONG == 32 &&
485 	    __builtin_constant_p(cpu_has_clo_clz) && cpu_has_clo_clz) {
486 		__asm__(
487 		"	.set	push					\n"
488 		"	.set	mips32					\n"
489 		"	clz	%0, %1					\n"
490 		"	.set	pop					\n"
491 		: "=r" (num)
492 		: "r" (word));
493 
494 		return 31 - num;
495 	}
496 
497 	if (BITS_PER_LONG == 64 &&
498 	    __builtin_constant_p(cpu_has_mips64) && cpu_has_mips64) {
499 		__asm__(
500 		"	.set	push					\n"
501 		"	.set	mips64					\n"
502 		"	dclz	%0, %1					\n"
503 		"	.set	pop					\n"
504 		: "=r" (num)
505 		: "r" (word));
506 
507 		return 63 - num;
508 	}
509 
510 	num = BITS_PER_LONG - 1;
511 
512 #if BITS_PER_LONG == 64
513 	if (!(word & (~0ul << 32))) {
514 		num -= 32;
515 		word <<= 32;
516 	}
517 #endif
518 	if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
519 		num -= 16;
520 		word <<= 16;
521 	}
522 	if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
523 		num -= 8;
524 		word <<= 8;
525 	}
526 	if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
527 		num -= 4;
528 		word <<= 4;
529 	}
530 	if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
531 		num -= 2;
532 		word <<= 2;
533 	}
534 	if (!(word & (~0ul << (BITS_PER_LONG-1))))
535 		num -= 1;
536 	return num;
537 }
538 
539 /*
540  * __ffs - find first bit in word.
541  * @word: The word to search
542  *
543  * Returns 0..SZLONG-1
544  * Undefined if no bit exists, so code should check against 0 first.
545  */
546 static inline unsigned long __ffs(unsigned long word)
547 {
548 	return __fls(word & -word);
549 }
550 
551 /*
552  * fls - find last bit set.
553  * @word: The word to search
554  *
555  * This is defined the same way as ffs.
556  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
557  */
558 static inline int fls(int x)
559 {
560 	int r;
561 
562 	if (__builtin_constant_p(cpu_has_clo_clz) && cpu_has_clo_clz) {
563 		__asm__(
564 		"	.set	push					\n"
565 		"	.set	mips32					\n"
566 		"	clz	%0, %1					\n"
567 		"	.set	pop					\n"
568 		: "=r" (x)
569 		: "r" (x));
570 
571 		return 32 - x;
572 	}
573 
574 	r = 32;
575 	if (!x)
576 		return 0;
577 	if (!(x & 0xffff0000u)) {
578 		x <<= 16;
579 		r -= 16;
580 	}
581 	if (!(x & 0xff000000u)) {
582 		x <<= 8;
583 		r -= 8;
584 	}
585 	if (!(x & 0xf0000000u)) {
586 		x <<= 4;
587 		r -= 4;
588 	}
589 	if (!(x & 0xc0000000u)) {
590 		x <<= 2;
591 		r -= 2;
592 	}
593 	if (!(x & 0x80000000u)) {
594 		x <<= 1;
595 		r -= 1;
596 	}
597 	return r;
598 }
599 
600 #include <asm-generic/bitops/fls64.h>
601 
602 /*
603  * ffs - find first bit set.
604  * @word: The word to search
605  *
606  * This is defined the same way as
607  * the libc and compiler builtin ffs routines, therefore
608  * differs in spirit from the above ffz (man ffs).
609  */
610 static inline int ffs(int word)
611 {
612 	if (!word)
613 		return 0;
614 
615 	return fls(word & -word);
616 }
617 
618 #include <asm-generic/bitops/ffz.h>
619 #include <asm-generic/bitops/find.h>
620 
621 #ifdef __KERNEL__
622 
623 #include <asm-generic/bitops/sched.h>
624 
625 #include <asm/arch_hweight.h>
626 #include <asm-generic/bitops/const_hweight.h>
627 
628 #include <asm-generic/bitops/le.h>
629 #include <asm-generic/bitops/ext2-atomic.h>
630 
631 #endif /* __KERNEL__ */
632 
633 #endif /* _ASM_BITOPS_H */
634