diff options
Diffstat (limited to 'include/asm-x86/bitops.h')
| -rw-r--r-- | include/asm-x86/bitops.h | 70 |
1 files changed, 48 insertions, 22 deletions
diff --git a/include/asm-x86/bitops.h b/include/asm-x86/bitops.h index ee4b3ead6a4..cfb2b64f76e 100644 --- a/include/asm-x86/bitops.h +++ b/include/asm-x86/bitops.h @@ -23,11 +23,21 @@ #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1) /* Technically wrong, but this avoids compilation errors on some gcc versions. */ -#define ADDR "=m" (*(volatile long *) addr) +#define BITOP_ADDR(x) "=m" (*(volatile long *) (x)) #else -#define ADDR "+m" (*(volatile long *) addr) +#define BITOP_ADDR(x) "+m" (*(volatile long *) (x)) #endif +#define ADDR BITOP_ADDR(addr) + +/* + * We do the locked ops that don't return the old value as + * a mask operation on a byte. + */ +#define IS_IMMEDIATE(nr) (__builtin_constant_p(nr)) +#define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3)) +#define CONST_MASK(nr) (1 << ((nr) & 7)) + /** * set_bit - Atomically set a bit in memory * @nr: the bit to set @@ -43,9 +53,17 @@ * Note that @nr may be almost arbitrarily large; this function is not * restricted to acting on a single-word quantity. */ -static inline void set_bit(int nr, volatile void *addr) +static inline void set_bit(unsigned int nr, volatile unsigned long *addr) { - asm volatile(LOCK_PREFIX "bts %1,%0" : ADDR : "Ir" (nr) : "memory"); + if (IS_IMMEDIATE(nr)) { + asm volatile(LOCK_PREFIX "orb %1,%0" + : CONST_MASK_ADDR(nr, addr) + : "iq" ((u8)CONST_MASK(nr)) + : "memory"); + } else { + asm volatile(LOCK_PREFIX "bts %1,%0" + : BITOP_ADDR(addr) : "Ir" (nr) : "memory"); + } } /** @@ -57,7 +75,7 @@ static inline void set_bit(int nr, volatile void *addr) * If it's called on the same region of memory simultaneously, the effect * may be that only one operation succeeds. */ -static inline void __set_bit(int nr, volatile void *addr) +static inline void __set_bit(int nr, volatile unsigned long *addr) { asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory"); } @@ -72,9 +90,17 @@ static inline void __set_bit(int nr, volatile void *addr) * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() * in order to ensure changes are visible on other processors. */ -static inline void clear_bit(int nr, volatile void *addr) +static inline void clear_bit(int nr, volatile unsigned long *addr) { - asm volatile(LOCK_PREFIX "btr %1,%0" : ADDR : "Ir" (nr)); + if (IS_IMMEDIATE(nr)) { + asm volatile(LOCK_PREFIX "andb %1,%0" + : CONST_MASK_ADDR(nr, addr) + : "iq" ((u8)~CONST_MASK(nr))); + } else { + asm volatile(LOCK_PREFIX "btr %1,%0" + : BITOP_ADDR(addr) + : "Ir" (nr)); + } } /* @@ -85,13 +111,13 @@ static inline void clear_bit(int nr, volatile void *addr) * clear_bit() is atomic and implies release semantics before the memory * operation. It can be used for an unlock. */ -static inline void clear_bit_unlock(unsigned nr, volatile void *addr) +static inline void clear_bit_unlock(unsigned nr, volatile unsigned long *addr) { barrier(); clear_bit(nr, addr); } -static inline void __clear_bit(int nr, volatile void *addr) +static inline void __clear_bit(int nr, volatile unsigned long *addr) { asm volatile("btr %1,%0" : ADDR : "Ir" (nr)); } @@ -108,7 +134,7 @@ static inline void __clear_bit(int nr, volatile void *addr) * No memory barrier is required here, because x86 cannot reorder stores past * older loads. Same principle as spin_unlock. */ -static inline void __clear_bit_unlock(unsigned nr, volatile void *addr) +static inline void __clear_bit_unlock(unsigned nr, volatile unsigned long *addr) { barrier(); __clear_bit(nr, addr); @@ -126,7 +152,7 @@ static inline void __clear_bit_unlock(unsigned nr, volatile void *addr) * If it's called on the same region of memory simultaneously, the effect * may be that only one operation succeeds. */ -static inline void __change_bit(int nr, volatile void *addr) +static inline void __change_bit(int nr, volatile unsigned long *addr) { asm volatile("btc %1,%0" : ADDR : "Ir" (nr)); } @@ -140,7 +166,7 @@ static inline void __change_bit(int nr, volatile void *addr) * Note that @nr may be almost arbitrarily large; this function is not * restricted to acting on a single-word quantity. */ -static inline void change_bit(int nr, volatile void *addr) +static inline void change_bit(int nr, volatile unsigned long *addr) { asm volatile(LOCK_PREFIX "btc %1,%0" : ADDR : "Ir" (nr)); } @@ -153,7 +179,7 @@ static inline void change_bit(int nr, volatile void *addr) * This operation is atomic and cannot be reordered. * It also implies a memory barrier. */ -static inline int test_and_set_bit(int nr, volatile void *addr) +static inline int test_and_set_bit(int nr, volatile unsigned long *addr) { int oldbit; @@ -170,7 +196,7 @@ static inline int test_and_set_bit(int nr, volatile void *addr) * * This is the same as test_and_set_bit on x86. */ -static inline int test_and_set_bit_lock(int nr, volatile void *addr) +static inline int test_and_set_bit_lock(int nr, volatile unsigned long *addr) { return test_and_set_bit(nr, addr); } @@ -184,7 +210,7 @@ static inline int test_and_set_bit_lock(int nr, volatile void *addr) * If two examples of this operation race, one can appear to succeed * but actually fail. You must protect multiple accesses with a lock. */ -static inline int __test_and_set_bit(int nr, volatile void *addr) +static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) { int oldbit; @@ -203,7 +229,7 @@ static inline int __test_and_set_bit(int nr, volatile void *addr) * This operation is atomic and cannot be reordered. * It also implies a memory barrier. */ -static inline int test_and_clear_bit(int nr, volatile void *addr) +static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) { int oldbit; @@ -223,7 +249,7 @@ static inline int test_and_clear_bit(int nr, volatile void *addr) * If two examples of this operation race, one can appear to succeed * but actually fail. You must protect multiple accesses with a lock. */ -static inline int __test_and_clear_bit(int nr, volatile void *addr) +static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) { int oldbit; @@ -235,7 +261,7 @@ static inline int __test_and_clear_bit(int nr, volatile void *addr) } /* WARNING: non atomic and it can be reordered! */ -static inline int __test_and_change_bit(int nr, volatile void *addr) +static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) { int oldbit; @@ -255,7 +281,7 @@ static inline int __test_and_change_bit(int nr, volatile void *addr) * This operation is atomic and cannot be reordered. * It also implies a memory barrier. */ -static inline int test_and_change_bit(int nr, volatile void *addr) +static inline int test_and_change_bit(int nr, volatile unsigned long *addr) { int oldbit; @@ -266,13 +292,13 @@ static inline int test_and_change_bit(int nr, volatile void *addr) return oldbit; } -static inline int constant_test_bit(int nr, const volatile void *addr) +static inline int constant_test_bit(int nr, const volatile unsigned long *addr) { return ((1UL << (nr % BITS_PER_LONG)) & (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0; } -static inline int variable_test_bit(int nr, volatile const void *addr) +static inline int variable_test_bit(int nr, volatile const unsigned long *addr) { int oldbit; @@ -330,7 +356,7 @@ static inline unsigned long ffz(unsigned long word) * __fls: find last set bit in word * @word: The word to search * - * Undefined if no zero exists, so code should check against ~0UL first. + * Undefined if no set bit exists, so code should check against 0 first. */ static inline unsigned long __fls(unsigned long word) { |