thermal: fix Mediatek thermal controller build
[linux/fpc-iii.git] / arch / x86 / include / asm / bitops.h
blob7766d1cf096e80d56562d63876f8ca65df869199
1 #ifndef _ASM_X86_BITOPS_H
2 #define _ASM_X86_BITOPS_H
4 /*
5 * Copyright 1992, Linus Torvalds.
7 * Note: inlines with more than a single statement should be marked
8 * __always_inline to avoid problems with older gcc's inlining heuristics.
9 */
11 #ifndef _LINUX_BITOPS_H
12 #error only <linux/bitops.h> can be included directly
13 #endif
15 #include <linux/compiler.h>
16 #include <asm/alternative.h>
17 #include <asm/rmwcc.h>
18 #include <asm/barrier.h>
20 #if BITS_PER_LONG == 32
21 # define _BITOPS_LONG_SHIFT 5
22 #elif BITS_PER_LONG == 64
23 # define _BITOPS_LONG_SHIFT 6
24 #else
25 # error "Unexpected BITS_PER_LONG"
26 #endif
28 #define BIT_64(n) (U64_C(1) << (n))
31 * These have to be done with inline assembly: that way the bit-setting
32 * is guaranteed to be atomic. All bit operations return 0 if the bit
33 * was cleared before the operation and != 0 if it was not.
35 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
38 #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
39 /* Technically wrong, but this avoids compilation errors on some gcc
40 versions. */
41 #define BITOP_ADDR(x) "=m" (*(volatile long *) (x))
42 #else
43 #define BITOP_ADDR(x) "+m" (*(volatile long *) (x))
44 #endif
46 #define ADDR BITOP_ADDR(addr)
49 * We do the locked ops that don't return the old value as
50 * a mask operation on a byte.
52 #define IS_IMMEDIATE(nr) (__builtin_constant_p(nr))
53 #define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3))
54 #define CONST_MASK(nr) (1 << ((nr) & 7))
56 /**
57 * set_bit - Atomically set a bit in memory
58 * @nr: the bit to set
59 * @addr: the address to start counting from
61 * This function is atomic and may not be reordered. See __set_bit()
62 * if you do not require the atomic guarantees.
64 * Note: there are no guarantees that this function will not be reordered
65 * on non x86 architectures, so if you are writing portable code,
66 * make sure not to rely on its reordering guarantees.
68 * Note that @nr may be almost arbitrarily large; this function is not
69 * restricted to acting on a single-word quantity.
71 static __always_inline void
72 set_bit(long nr, volatile unsigned long *addr)
74 if (IS_IMMEDIATE(nr)) {
75 asm volatile(LOCK_PREFIX "orb %1,%0"
76 : CONST_MASK_ADDR(nr, addr)
77 : "iq" ((u8)CONST_MASK(nr))
78 : "memory");
79 } else {
80 asm volatile(LOCK_PREFIX "bts %1,%0"
81 : BITOP_ADDR(addr) : "Ir" (nr) : "memory");
85 /**
86 * __set_bit - Set a bit in memory
87 * @nr: the bit to set
88 * @addr: the address to start counting from
90 * Unlike set_bit(), this function is non-atomic and may be reordered.
91 * If it's called on the same region of memory simultaneously, the effect
92 * may be that only one operation succeeds.
94 static __always_inline void __set_bit(long nr, volatile unsigned long *addr)
96 asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory");
99 /**
100 * clear_bit - Clears a bit in memory
101 * @nr: Bit to clear
102 * @addr: Address to start counting from
104 * clear_bit() is atomic and may not be reordered. However, it does
105 * not contain a memory barrier, so if it is used for locking purposes,
106 * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
107 * in order to ensure changes are visible on other processors.
109 static __always_inline void
110 clear_bit(long nr, volatile unsigned long *addr)
112 if (IS_IMMEDIATE(nr)) {
113 asm volatile(LOCK_PREFIX "andb %1,%0"
114 : CONST_MASK_ADDR(nr, addr)
115 : "iq" ((u8)~CONST_MASK(nr)));
116 } else {
117 asm volatile(LOCK_PREFIX "btr %1,%0"
118 : BITOP_ADDR(addr)
119 : "Ir" (nr));
124 * clear_bit_unlock - Clears a bit in memory
125 * @nr: Bit to clear
126 * @addr: Address to start counting from
128 * clear_bit() is atomic and implies release semantics before the memory
129 * operation. It can be used for an unlock.
131 static __always_inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
133 barrier();
134 clear_bit(nr, addr);
137 static __always_inline void __clear_bit(long nr, volatile unsigned long *addr)
139 asm volatile("btr %1,%0" : ADDR : "Ir" (nr));
143 * __clear_bit_unlock - Clears a bit in memory
144 * @nr: Bit to clear
145 * @addr: Address to start counting from
147 * __clear_bit() is non-atomic and implies release semantics before the memory
148 * operation. It can be used for an unlock if no other CPUs can concurrently
149 * modify other bits in the word.
151 * No memory barrier is required here, because x86 cannot reorder stores past
152 * older loads. Same principle as spin_unlock.
154 static __always_inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
156 barrier();
157 __clear_bit(nr, addr);
161 * __change_bit - Toggle a bit in memory
162 * @nr: the bit to change
163 * @addr: the address to start counting from
165 * Unlike change_bit(), this function is non-atomic and may be reordered.
166 * If it's called on the same region of memory simultaneously, the effect
167 * may be that only one operation succeeds.
169 static __always_inline void __change_bit(long nr, volatile unsigned long *addr)
171 asm volatile("btc %1,%0" : ADDR : "Ir" (nr));
175 * change_bit - Toggle a bit in memory
176 * @nr: Bit to change
177 * @addr: Address to start counting from
179 * change_bit() is atomic and may not be reordered.
180 * Note that @nr may be almost arbitrarily large; this function is not
181 * restricted to acting on a single-word quantity.
183 static __always_inline void change_bit(long nr, volatile unsigned long *addr)
185 if (IS_IMMEDIATE(nr)) {
186 asm volatile(LOCK_PREFIX "xorb %1,%0"
187 : CONST_MASK_ADDR(nr, addr)
188 : "iq" ((u8)CONST_MASK(nr)));
189 } else {
190 asm volatile(LOCK_PREFIX "btc %1,%0"
191 : BITOP_ADDR(addr)
192 : "Ir" (nr));
197 * test_and_set_bit - Set a bit and return its old value
198 * @nr: Bit to set
199 * @addr: Address to count from
201 * This operation is atomic and cannot be reordered.
202 * It also implies a memory barrier.
204 static __always_inline int test_and_set_bit(long nr, volatile unsigned long *addr)
206 GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, "Ir", nr, "%0", "c");
210 * test_and_set_bit_lock - Set a bit and return its old value for lock
211 * @nr: Bit to set
212 * @addr: Address to count from
214 * This is the same as test_and_set_bit on x86.
216 static __always_inline int
217 test_and_set_bit_lock(long nr, volatile unsigned long *addr)
219 return test_and_set_bit(nr, addr);
223 * __test_and_set_bit - Set a bit and return its old value
224 * @nr: Bit to set
225 * @addr: Address to count from
227 * This operation is non-atomic and can be reordered.
228 * If two examples of this operation race, one can appear to succeed
229 * but actually fail. You must protect multiple accesses with a lock.
231 static __always_inline int __test_and_set_bit(long nr, volatile unsigned long *addr)
233 int oldbit;
235 asm("bts %2,%1\n\t"
236 "sbb %0,%0"
237 : "=r" (oldbit), ADDR
238 : "Ir" (nr));
239 return oldbit;
243 * test_and_clear_bit - Clear a bit and return its old value
244 * @nr: Bit to clear
245 * @addr: Address to count from
247 * This operation is atomic and cannot be reordered.
248 * It also implies a memory barrier.
250 static __always_inline int test_and_clear_bit(long nr, volatile unsigned long *addr)
252 GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, "Ir", nr, "%0", "c");
256 * __test_and_clear_bit - Clear a bit and return its old value
257 * @nr: Bit to clear
258 * @addr: Address to count from
260 * This operation is non-atomic and can be reordered.
261 * If two examples of this operation race, one can appear to succeed
262 * but actually fail. You must protect multiple accesses with a lock.
264 * Note: the operation is performed atomically with respect to
265 * the local CPU, but not other CPUs. Portable code should not
266 * rely on this behaviour.
267 * KVM relies on this behaviour on x86 for modifying memory that is also
268 * accessed from a hypervisor on the same CPU if running in a VM: don't change
269 * this without also updating arch/x86/kernel/kvm.c
271 static __always_inline int __test_and_clear_bit(long nr, volatile unsigned long *addr)
273 int oldbit;
275 asm volatile("btr %2,%1\n\t"
276 "sbb %0,%0"
277 : "=r" (oldbit), ADDR
278 : "Ir" (nr));
279 return oldbit;
282 /* WARNING: non atomic and it can be reordered! */
283 static __always_inline int __test_and_change_bit(long nr, volatile unsigned long *addr)
285 int oldbit;
287 asm volatile("btc %2,%1\n\t"
288 "sbb %0,%0"
289 : "=r" (oldbit), ADDR
290 : "Ir" (nr) : "memory");
292 return oldbit;
296 * test_and_change_bit - Change a bit and return its old value
297 * @nr: Bit to change
298 * @addr: Address to count from
300 * This operation is atomic and cannot be reordered.
301 * It also implies a memory barrier.
303 static __always_inline int test_and_change_bit(long nr, volatile unsigned long *addr)
305 GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, "Ir", nr, "%0", "c");
308 static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr)
310 return ((1UL << (nr & (BITS_PER_LONG-1))) &
311 (addr[nr >> _BITOPS_LONG_SHIFT])) != 0;
314 static __always_inline int variable_test_bit(long nr, volatile const unsigned long *addr)
316 int oldbit;
318 asm volatile("bt %2,%1\n\t"
319 "sbb %0,%0"
320 : "=r" (oldbit)
321 : "m" (*(unsigned long *)addr), "Ir" (nr));
323 return oldbit;
326 #if 0 /* Fool kernel-doc since it doesn't do macros yet */
328 * test_bit - Determine whether a bit is set
329 * @nr: bit number to test
330 * @addr: Address to start counting from
332 static int test_bit(int nr, const volatile unsigned long *addr);
333 #endif
335 #define test_bit(nr, addr) \
336 (__builtin_constant_p((nr)) \
337 ? constant_test_bit((nr), (addr)) \
338 : variable_test_bit((nr), (addr)))
341 * __ffs - find first set bit in word
342 * @word: The word to search
344 * Undefined if no bit exists, so code should check against 0 first.
346 static __always_inline unsigned long __ffs(unsigned long word)
348 asm("rep; bsf %1,%0"
349 : "=r" (word)
350 : "rm" (word));
351 return word;
355 * ffz - find first zero bit in word
356 * @word: The word to search
358 * Undefined if no zero exists, so code should check against ~0UL first.
360 static __always_inline unsigned long ffz(unsigned long word)
362 asm("rep; bsf %1,%0"
363 : "=r" (word)
364 : "r" (~word));
365 return word;
369 * __fls: find last set bit in word
370 * @word: The word to search
372 * Undefined if no set bit exists, so code should check against 0 first.
374 static __always_inline unsigned long __fls(unsigned long word)
376 asm("bsr %1,%0"
377 : "=r" (word)
378 : "rm" (word));
379 return word;
382 #undef ADDR
384 #ifdef __KERNEL__
386 * ffs - find first set bit in word
387 * @x: the word to search
389 * This is defined the same way as the libc and compiler builtin ffs
390 * routines, therefore differs in spirit from the other bitops.
392 * ffs(value) returns 0 if value is 0 or the position of the first
393 * set bit if value is nonzero. The first (least significant) bit
394 * is at position 1.
396 static __always_inline int ffs(int x)
398 int r;
400 #ifdef CONFIG_X86_64
402 * AMD64 says BSFL won't clobber the dest reg if x==0; Intel64 says the
403 * dest reg is undefined if x==0, but their CPU architect says its
404 * value is written to set it to the same as before, except that the
405 * top 32 bits will be cleared.
407 * We cannot do this on 32 bits because at the very least some
408 * 486 CPUs did not behave this way.
410 asm("bsfl %1,%0"
411 : "=r" (r)
412 : "rm" (x), "0" (-1));
413 #elif defined(CONFIG_X86_CMOV)
414 asm("bsfl %1,%0\n\t"
415 "cmovzl %2,%0"
416 : "=&r" (r) : "rm" (x), "r" (-1));
417 #else
418 asm("bsfl %1,%0\n\t"
419 "jnz 1f\n\t"
420 "movl $-1,%0\n"
421 "1:" : "=r" (r) : "rm" (x));
422 #endif
423 return r + 1;
427 * fls - find last set bit in word
428 * @x: the word to search
430 * This is defined in a similar way as the libc and compiler builtin
431 * ffs, but returns the position of the most significant set bit.
433 * fls(value) returns 0 if value is 0 or the position of the last
434 * set bit if value is nonzero. The last (most significant) bit is
435 * at position 32.
437 static __always_inline int fls(int x)
439 int r;
441 #ifdef CONFIG_X86_64
443 * AMD64 says BSRL won't clobber the dest reg if x==0; Intel64 says the
444 * dest reg is undefined if x==0, but their CPU architect says its
445 * value is written to set it to the same as before, except that the
446 * top 32 bits will be cleared.
448 * We cannot do this on 32 bits because at the very least some
449 * 486 CPUs did not behave this way.
451 asm("bsrl %1,%0"
452 : "=r" (r)
453 : "rm" (x), "0" (-1));
454 #elif defined(CONFIG_X86_CMOV)
455 asm("bsrl %1,%0\n\t"
456 "cmovzl %2,%0"
457 : "=&r" (r) : "rm" (x), "rm" (-1));
458 #else
459 asm("bsrl %1,%0\n\t"
460 "jnz 1f\n\t"
461 "movl $-1,%0\n"
462 "1:" : "=r" (r) : "rm" (x));
463 #endif
464 return r + 1;
468 * fls64 - find last set bit in a 64-bit word
469 * @x: the word to search
471 * This is defined in a similar way as the libc and compiler builtin
472 * ffsll, but returns the position of the most significant set bit.
474 * fls64(value) returns 0 if value is 0 or the position of the last
475 * set bit if value is nonzero. The last (most significant) bit is
476 * at position 64.
478 #ifdef CONFIG_X86_64
479 static __always_inline int fls64(__u64 x)
481 int bitpos = -1;
483 * AMD64 says BSRQ won't clobber the dest reg if x==0; Intel64 says the
484 * dest reg is undefined if x==0, but their CPU architect says its
485 * value is written to set it to the same as before.
487 asm("bsrq %1,%q0"
488 : "+r" (bitpos)
489 : "rm" (x));
490 return bitpos + 1;
492 #else
493 #include <asm-generic/bitops/fls64.h>
494 #endif
496 #include <asm-generic/bitops/find.h>
498 #include <asm-generic/bitops/sched.h>
500 #include <asm/arch_hweight.h>
502 #include <asm-generic/bitops/const_hweight.h>
504 #include <asm-generic/bitops/le.h>
506 #include <asm-generic/bitops/ext2-atomic-setbit.h>
508 #endif /* __KERNEL__ */
509 #endif /* _ASM_X86_BITOPS_H */