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
6 * Copyright (c) 1994 - 1997, 99, 2000, 06, 07 Ralf Baechle (ralf@linux-mips.org)
7 * Copyright (c) 1999, 2000 Silicon Graphics, Inc.
12 #ifndef _LINUX_BITOPS_H
13 #error only <linux/bitops.h> can be included directly
16 #include <linux/compiler.h>
17 #include <linux/irqflags.h>
18 #include <linux/types.h>
19 #include <asm/barrier.h>
21 #include <asm/byteorder.h> /* sigh ... */
22 #include <asm/cpu-features.h>
23 #include <asm/sgidefs.h>
26 #if _MIPS_SZLONG == 32
28 #define SZLONG_MASK 31UL
33 #elif _MIPS_SZLONG == 64
35 #define SZLONG_MASK 63UL
43 * clear_bit() doesn't provide any barrier for the compiler.
45 #define smp_mb__before_clear_bit() smp_mb__before_llsc()
46 #define smp_mb__after_clear_bit() smp_llsc_mb()
49 * set_bit - Atomically set a bit in memory
51 * @addr: the address to start counting from
53 * This function is atomic and may not be reordered. See __set_bit()
54 * if you do not require the atomic guarantees.
55 * Note that @nr may be almost arbitrarily large; this function is not
56 * restricted to acting on a single-word quantity.
58 static inline void set_bit(unsigned long nr
, volatile unsigned long *addr
)
60 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
61 unsigned short bit
= nr
& SZLONG_MASK
;
64 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
67 "1: " __LL
"%0, %1 # set_bit \n"
72 : "=&r" (temp
), "=m" (*m
)
73 : "ir" (1UL << bit
), "m" (*m
));
74 #ifdef CONFIG_CPU_MIPSR2
75 } else if (kernel_uses_llsc
&& __builtin_constant_p(bit
)) {
78 " " __LL
"%0, %1 # set_bit \n"
79 " " __INS
"%0, %3, %2, 1 \n"
81 : "=&r" (temp
), "+m" (*m
)
82 : "ir" (bit
), "r" (~0));
83 } while (unlikely(!temp
));
84 #endif /* CONFIG_CPU_MIPSR2 */
85 } else if (kernel_uses_llsc
) {
89 " " __LL
"%0, %1 # set_bit \n"
93 : "=&r" (temp
), "+m" (*m
)
95 } while (unlikely(!temp
));
97 volatile unsigned long *a
= addr
;
101 a
+= nr
>> SZLONG_LOG
;
103 raw_local_irq_save(flags
);
105 raw_local_irq_restore(flags
);
110 * clear_bit - Clears a bit in memory
112 * @addr: Address to start counting from
114 * clear_bit() is atomic and may not be reordered. However, it does
115 * not contain a memory barrier, so if it is used for locking purposes,
116 * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
117 * in order to ensure changes are visible on other processors.
119 static inline void clear_bit(unsigned long nr
, volatile unsigned long *addr
)
121 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
122 unsigned short bit
= nr
& SZLONG_MASK
;
125 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
126 __asm__
__volatile__(
128 "1: " __LL
"%0, %1 # clear_bit \n"
133 : "=&r" (temp
), "+m" (*m
)
134 : "ir" (~(1UL << bit
)));
135 #ifdef CONFIG_CPU_MIPSR2
136 } else if (kernel_uses_llsc
&& __builtin_constant_p(bit
)) {
138 __asm__
__volatile__(
139 " " __LL
"%0, %1 # clear_bit \n"
140 " " __INS
"%0, $0, %2, 1 \n"
142 : "=&r" (temp
), "+m" (*m
)
144 } while (unlikely(!temp
));
145 #endif /* CONFIG_CPU_MIPSR2 */
146 } else if (kernel_uses_llsc
) {
148 __asm__
__volatile__(
150 " " __LL
"%0, %1 # clear_bit \n"
154 : "=&r" (temp
), "+m" (*m
)
155 : "ir" (~(1UL << bit
)));
156 } while (unlikely(!temp
));
158 volatile unsigned long *a
= addr
;
162 a
+= nr
>> SZLONG_LOG
;
164 raw_local_irq_save(flags
);
166 raw_local_irq_restore(flags
);
171 * clear_bit_unlock - Clears a bit in memory
173 * @addr: Address to start counting from
175 * clear_bit() is atomic and implies release semantics before the memory
176 * operation. It can be used for an unlock.
178 static inline void clear_bit_unlock(unsigned long nr
, volatile unsigned long *addr
)
180 smp_mb__before_clear_bit();
185 * change_bit - Toggle a bit in memory
187 * @addr: Address to start counting from
189 * change_bit() is atomic and may not be reordered.
190 * Note that @nr may be almost arbitrarily large; this function is not
191 * restricted to acting on a single-word quantity.
193 static inline void change_bit(unsigned long nr
, volatile unsigned long *addr
)
195 unsigned short bit
= nr
& SZLONG_MASK
;
197 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
198 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
201 __asm__
__volatile__(
203 "1: " __LL
"%0, %1 # change_bit \n"
208 : "=&r" (temp
), "+m" (*m
)
209 : "ir" (1UL << bit
));
210 } else if (kernel_uses_llsc
) {
211 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
215 __asm__
__volatile__(
217 " " __LL
"%0, %1 # change_bit \n"
221 : "=&r" (temp
), "+m" (*m
)
222 : "ir" (1UL << bit
));
223 } while (unlikely(!temp
));
225 volatile unsigned long *a
= addr
;
229 a
+= nr
>> SZLONG_LOG
;
231 raw_local_irq_save(flags
);
233 raw_local_irq_restore(flags
);
238 * test_and_set_bit - Set a bit and return its old value
240 * @addr: Address to count from
242 * This operation is atomic and cannot be reordered.
243 * It also implies a memory barrier.
245 static inline int test_and_set_bit(unsigned long nr
,
246 volatile unsigned long *addr
)
248 unsigned short bit
= nr
& SZLONG_MASK
;
251 smp_mb__before_llsc();
253 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
254 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
257 __asm__
__volatile__(
259 "1: " __LL
"%0, %1 # test_and_set_bit \n"
265 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
268 } else if (kernel_uses_llsc
) {
269 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
273 __asm__
__volatile__(
275 " " __LL
"%0, %1 # test_and_set_bit \n"
279 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
282 } while (unlikely(!res
));
284 res
= temp
& (1UL << bit
);
286 volatile unsigned long *a
= addr
;
290 a
+= nr
>> SZLONG_LOG
;
292 raw_local_irq_save(flags
);
295 raw_local_irq_restore(flags
);
304 * test_and_set_bit_lock - Set a bit and return its old value
306 * @addr: Address to count from
308 * This operation is atomic and implies acquire ordering semantics
309 * after the memory operation.
311 static inline int test_and_set_bit_lock(unsigned long nr
,
312 volatile unsigned long *addr
)
314 unsigned short bit
= nr
& SZLONG_MASK
;
317 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
318 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
321 __asm__
__volatile__(
323 "1: " __LL
"%0, %1 # test_and_set_bit \n"
329 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
332 } else if (kernel_uses_llsc
) {
333 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
337 __asm__
__volatile__(
339 " " __LL
"%0, %1 # test_and_set_bit \n"
343 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
346 } while (unlikely(!res
));
348 res
= temp
& (1UL << bit
);
350 volatile unsigned long *a
= addr
;
354 a
+= nr
>> SZLONG_LOG
;
356 raw_local_irq_save(flags
);
359 raw_local_irq_restore(flags
);
367 * test_and_clear_bit - Clear a bit and return its old value
369 * @addr: Address to count from
371 * This operation is atomic and cannot be reordered.
372 * It also implies a memory barrier.
374 static inline int test_and_clear_bit(unsigned long nr
,
375 volatile unsigned long *addr
)
377 unsigned short bit
= nr
& SZLONG_MASK
;
380 smp_mb__before_llsc();
382 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
383 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
386 __asm__
__volatile__(
388 "1: " __LL
"%0, %1 # test_and_clear_bit \n"
395 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
398 #ifdef CONFIG_CPU_MIPSR2
399 } else if (kernel_uses_llsc
&& __builtin_constant_p(nr
)) {
400 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
404 __asm__
__volatile__(
405 " " __LL
"%0, %1 # test_and_clear_bit \n"
406 " " __EXT
"%2, %0, %3, 1 \n"
407 " " __INS
"%0, $0, %3, 1 \n"
409 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
412 } while (unlikely(!temp
));
414 } else if (kernel_uses_llsc
) {
415 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
419 __asm__
__volatile__(
421 " " __LL
"%0, %1 # test_and_clear_bit \n"
426 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
429 } while (unlikely(!res
));
431 res
= temp
& (1UL << bit
);
433 volatile unsigned long *a
= addr
;
437 a
+= nr
>> SZLONG_LOG
;
439 raw_local_irq_save(flags
);
442 raw_local_irq_restore(flags
);
451 * test_and_change_bit - Change a bit and return its old value
453 * @addr: Address to count from
455 * This operation is atomic and cannot be reordered.
456 * It also implies a memory barrier.
458 static inline int test_and_change_bit(unsigned long nr
,
459 volatile unsigned long *addr
)
461 unsigned short bit
= nr
& SZLONG_MASK
;
464 smp_mb__before_llsc();
466 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
467 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
470 __asm__
__volatile__(
472 "1: " __LL
"%0, %1 # test_and_change_bit \n"
478 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
481 } else if (kernel_uses_llsc
) {
482 unsigned long *m
= ((unsigned long *) addr
) + (nr
>> SZLONG_LOG
);
486 __asm__
__volatile__(
488 " " __LL
"%0, %1 # test_and_change_bit \n"
490 " " __SC
"\t%2, %1 \n"
492 : "=&r" (temp
), "+m" (*m
), "=&r" (res
)
495 } while (unlikely(!res
));
497 res
= temp
& (1UL << bit
);
499 volatile unsigned long *a
= addr
;
503 a
+= nr
>> SZLONG_LOG
;
505 raw_local_irq_save(flags
);
508 raw_local_irq_restore(flags
);
516 #include <asm-generic/bitops/non-atomic.h>
519 * __clear_bit_unlock - Clears a bit in memory
521 * @addr: Address to start counting from
523 * __clear_bit() is non-atomic and implies release semantics before the memory
524 * operation. It can be used for an unlock if no other CPUs can concurrently
525 * modify other bits in the word.
527 static inline void __clear_bit_unlock(unsigned long nr
, volatile unsigned long *addr
)
530 __clear_bit(nr
, addr
);
534 * Return the bit position (0..63) of the most significant 1 bit in a word
535 * Returns -1 if no 1 bit exists
537 static inline unsigned long __fls(unsigned long word
)
541 if (BITS_PER_LONG
== 32 &&
542 __builtin_constant_p(cpu_has_clo_clz
) && cpu_has_clo_clz
) {
554 if (BITS_PER_LONG
== 64 &&
555 __builtin_constant_p(cpu_has_mips64
) && cpu_has_mips64
) {
567 num
= BITS_PER_LONG
- 1;
569 #if BITS_PER_LONG == 64
570 if (!(word
& (~0ul << 32))) {
575 if (!(word
& (~0ul << (BITS_PER_LONG
-16)))) {
579 if (!(word
& (~0ul << (BITS_PER_LONG
-8)))) {
583 if (!(word
& (~0ul << (BITS_PER_LONG
-4)))) {
587 if (!(word
& (~0ul << (BITS_PER_LONG
-2)))) {
591 if (!(word
& (~0ul << (BITS_PER_LONG
-1))))
597 * __ffs - find first bit in word.
598 * @word: The word to search
600 * Returns 0..SZLONG-1
601 * Undefined if no bit exists, so code should check against 0 first.
603 static inline unsigned long __ffs(unsigned long word
)
605 return __fls(word
& -word
);
609 * fls - find last bit set.
610 * @word: The word to search
612 * This is defined the same way as ffs.
613 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
615 static inline int fls(int x
)
619 if (__builtin_constant_p(cpu_has_clo_clz
) && cpu_has_clo_clz
) {
620 __asm__("clz %0, %1" : "=r" (x
) : "r" (x
));
628 if (!(x
& 0xffff0000u
)) {
632 if (!(x
& 0xff000000u
)) {
636 if (!(x
& 0xf0000000u
)) {
640 if (!(x
& 0xc0000000u
)) {
644 if (!(x
& 0x80000000u
)) {
651 #include <asm-generic/bitops/fls64.h>
654 * ffs - find first bit set.
655 * @word: The word to search
657 * This is defined the same way as
658 * the libc and compiler builtin ffs routines, therefore
659 * differs in spirit from the above ffz (man ffs).
661 static inline int ffs(int word
)
666 return fls(word
& -word
);
669 #include <asm-generic/bitops/ffz.h>
670 #include <asm-generic/bitops/find.h>
674 #include <asm-generic/bitops/sched.h>
676 #include <asm/arch_hweight.h>
677 #include <asm-generic/bitops/const_hweight.h>
679 #include <asm-generic/bitops/le.h>
680 #include <asm-generic/bitops/ext2-atomic.h>
682 #endif /* __KERNEL__ */
684 #endif /* _ASM_BITOPS_H */