diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-x86/bitops.h | 315 | ||||
| -rw-r--r-- | include/asm-x86/bitops_32.h | 308 | ||||
| -rw-r--r-- | include/asm-x86/bitops_64.h | 297 |
3 files changed, 315 insertions, 605 deletions
diff --git a/include/asm-x86/bitops.h b/include/asm-x86/bitops.h index 07e3f6d..c6dd7e2 100644 --- a/include/asm-x86/bitops.h +++ b/include/asm-x86/bitops.h @@ -1,5 +1,320 @@ +#ifndef _ASM_X86_BITOPS_H +#define _ASM_X86_BITOPS_H + +/* + * Copyright 1992, Linus Torvalds. + */ + +#ifndef _LINUX_BITOPS_H +#error only <linux/bitops.h> can be included directly +#endif + +#include <linux/compiler.h> +#include <asm/alternative.h> + +/* + * These have to be done with inline assembly: that way the bit-setting + * is guaranteed to be atomic. All bit operations return 0 if the bit + * was cleared before the operation and != 0 if it was not. + * + * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). + */ + +#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) +#else +#define ADDR "+m" (*(volatile long *) addr) +#endif + +/** + * set_bit - Atomically set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * This function is atomic and may not be reordered. See __set_bit() + * if you do not require the atomic guarantees. + * + * Note: there are no guarantees that this function will not be reordered + * on non x86 architectures, so if you are writing portable code, + * make sure not to rely on its reordering guarantees. + * + * 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 unsigned long *addr) +{ + asm volatile(LOCK_PREFIX "bts %1,%0" + : ADDR + : "Ir" (nr) : "memory"); +} + +/** + * __set_bit - Set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * Unlike set_bit(), this function is non-atomic and may be reordered. + * 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 unsigned long *addr) +{ + asm volatile("bts %1,%0" + : ADDR + : "Ir" (nr) : "memory"); +} + + +/** + * clear_bit - Clears a bit in memory + * @nr: Bit to clear + * @addr: Address to start counting from + * + * clear_bit() is atomic and may not be reordered. However, it does + * not contain a memory barrier, so if it is used for locking purposes, + * 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 unsigned long *addr) +{ + asm volatile(LOCK_PREFIX "btr %1,%0" + : ADDR + : "Ir" (nr)); +} + +/* + * clear_bit_unlock - Clears a bit in memory + * @nr: Bit to clear + * @addr: Address to start counting from + * + * 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 unsigned long *addr) +{ + barrier(); + clear_bit(nr, addr); +} + +static inline void __clear_bit(int nr, volatile unsigned long *addr) +{ + asm volatile("btr %1,%0" : ADDR : "Ir" (nr)); +} + +/* + * __clear_bit_unlock - Clears a bit in memory + * @nr: Bit to clear + * @addr: Address to start counting from + * + * __clear_bit() is non-atomic and implies release semantics before the memory + * operation. It can be used for an unlock if no other CPUs can concurrently + * modify other bits in the word. + * + * 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 unsigned long *addr) +{ + barrier(); + __clear_bit(nr, addr); +} + +#define smp_mb__before_clear_bit() barrier() +#define smp_mb__after_clear_bit() barrier() + +/** + * __change_bit - Toggle a bit in memory + * @nr: the bit to change + * @addr: the address to start counting from + * + * Unlike change_bit(), this function is non-atomic and may be reordered. + * 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 unsigned long *addr) +{ + asm volatile("btc %1,%0" : ADDR : "Ir" (nr)); +} + +/** + * change_bit - Toggle a bit in memory + * @nr: Bit to change + * @addr: Address to start counting from + * + * change_bit() is atomic and may not be reordered. + * 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 unsigned long *addr) +{ + asm volatile(LOCK_PREFIX "btc %1,%0" + : ADDR : "Ir" (nr)); +} + +/** + * test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is atomic and cannot be reordered. + * It also implies a memory barrier. + */ +static inline int test_and_set_bit(int nr, volatile unsigned long *addr) +{ + int oldbit; + + asm volatile(LOCK_PREFIX "bts %2,%1\n\t" + "sbb %0,%0" + : "=r" (oldbit), ADDR + : "Ir" (nr) : "memory"); + + return oldbit; +} + +/** + * test_and_set_bit_lock - Set a bit and return its old value for lock + * @nr: Bit to set + * @addr: Address to count from + * + * This is the same as test_and_set_bit on x86. + */ +static inline int test_and_set_bit_lock(int nr, volatile unsigned long *addr) +{ + return test_and_set_bit(nr, addr); +} + +/** + * __test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * 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 unsigned long *addr) +{ + int oldbit; + + asm("bts %2,%1\n\t" + "sbb %0,%0" + : "=r" (oldbit), ADDR + : "Ir" (nr)); + return oldbit; +} + +/** + * test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This operation is atomic and cannot be reordered. + * It also implies a memory barrier. + */ +static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) +{ + int oldbit; + + asm volatile(LOCK_PREFIX "btr %2,%1\n\t" + "sbb %0,%0" + : "=r" (oldbit), ADDR + : "Ir" (nr) : "memory"); + + return oldbit; +} + +/** + * __test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * 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 unsigned long *addr) +{ + int oldbit; + + asm volatile("btr %2,%1\n\t" + "sbb %0,%0" + : "=r" (oldbit), ADDR + : "Ir" (nr)); + return oldbit; +} + +/* WARNING: non atomic and it can be reordered! */ +static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) +{ + int oldbit; + + asm volatile("btc %2,%1\n\t" + "sbb %0,%0" + : "=r" (oldbit), ADDR + : "Ir" (nr) : "memory"); + + return oldbit; +} + +/** + * test_and_change_bit - Change a bit and return its old value + * @nr: Bit to change + * @addr: Address to count from + * + * This operation is atomic and cannot be reordered. + * It also implies a memory barrier. + */ +static inline int test_and_change_bit(int nr, volatile unsigned long *addr) +{ + int oldbit; + + asm volatile(LOCK_PREFIX "btc %2,%1\n\t" + "sbb %0,%0" + : "=r" (oldbit), ADDR + : "Ir" (nr) : "memory"); + + return oldbit; +} + +static inline int constant_test_bit(int nr, const volatile unsigned long *addr) +{ + return ((1UL << (nr % BITS_PER_LONG)) & (addr[nr / BITS_PER_LONG])) != 0; +} + +static inline int variable_test_bit(int nr, volatile const unsigned long *addr) +{ + int oldbit; + + asm volatile("bt %2,%1\n\t" + "sbb %0,%0" + : "=r" (oldbit) + : "m" (*addr), "Ir" (nr)); + + return oldbit; +} + +#if 0 /* Fool kernel-doc since it doesn't do macros yet */ +/** + * test_bit - Determine whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + */ +static int test_bit(int nr, const volatile unsigned long *addr); +#endif + +#define test_bit(nr,addr) \ + (__builtin_constant_p(nr) ? \ + constant_test_bit((nr),(addr)) : \ + variable_test_bit((nr),(addr))) + +#undef ADDR + #ifdef CONFIG_X86_32 # include "bitops_32.h" #else # include "bitops_64.h" #endif + +#endif /* _ASM_X86_BITOPS_H */ diff --git a/include/asm-x86/bitops_32.h b/include/asm-x86/bitops_32.h index 5a29cce..e4d75fc 100644 --- a/include/asm-x86/bitops_32.h +++ b/include/asm-x86/bitops_32.h @@ -5,314 +5,6 @@ * Copyright 1992, Linus Torvalds. */ -#ifndef _LINUX_BITOPS_H -#error only <linux/bitops.h> can be included directly -#endif - -#include <linux/compiler.h> -#include <asm/alternative.h> - -/* - * These have to be done with inline assembly: that way the bit-setting - * is guaranteed to be atomic. All bit operations return 0 if the bit - * was cleared before the operation and != 0 if it was not. - * - * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). - */ - -#define ADDR (*(volatile long *) addr) - -/** - * set_bit - Atomically set a bit in memory - * @nr: the bit to set - * @addr: the address to start counting from - * - * This function is atomic and may not be reordered. See __set_bit() - * if you do not require the atomic guarantees. - * - * Note: there are no guarantees that this function will not be reordered - * on non x86 architectures, so if you are writing portable code, - * make sure not to rely on its reordering guarantees. - * - * 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 unsigned long *addr) -{ - __asm__ __volatile__( LOCK_PREFIX - "btsl %1,%0" - :"+m" (ADDR) - :"Ir" (nr)); -} - -/** - * __set_bit - Set a bit in memory - * @nr: the bit to set - * @addr: the address to start counting from - * - * Unlike set_bit(), this function is non-atomic and may be reordered. - * 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 unsigned long *addr) -{ - __asm__( - "btsl %1,%0" - :"+m" (ADDR) - :"Ir" (nr)); -} - -/** - * clear_bit - Clears a bit in memory - * @nr: Bit to clear - * @addr: Address to start counting from - * - * clear_bit() is atomic and may not be reordered. However, it does - * not contain a memory barrier, so if it is used for locking purposes, - * 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 unsigned long *addr) -{ - __asm__ __volatile__( LOCK_PREFIX - "btrl %1,%0" - :"+m" (ADDR) - :"Ir" (nr)); -} - -/* - * clear_bit_unlock - Clears a bit in memory - * @nr: Bit to clear - * @addr: Address to start counting from - * - * 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 long nr, volatile unsigned long *addr) -{ - barrier(); - clear_bit(nr, addr); -} - -static inline void __clear_bit(int nr, volatile unsigned long *addr) -{ - __asm__ __volatile__( - "btrl %1,%0" - :"+m" (ADDR) - :"Ir" (nr)); -} - -/* - * __clear_bit_unlock - Clears a bit in memory - * @nr: Bit to clear - * @addr: Address to start counting from - * - * __clear_bit() is non-atomic and implies release semantics before the memory - * operation. It can be used for an unlock if no other CPUs can concurrently - * modify other bits in the word. - * - * 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 long nr, volatile unsigned long *addr) -{ - barrier(); - __clear_bit(nr, addr); -} - -#define smp_mb__before_clear_bit() barrier() -#define smp_mb__after_clear_bit() barrier() - -/** - * __change_bit - Toggle a bit in memory - * @nr: the bit to change - * @addr: the address to start counting from - * - * Unlike change_bit(), this function is non-atomic and may be reordered. - * 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 unsigned long *addr) -{ - __asm__ __volatile__( - "btcl %1,%0" - :"+m" (ADDR) - :"Ir" (nr)); -} - -/** - * change_bit - Toggle a bit in memory - * @nr: Bit to change - * @addr: Address to start counting from - * - * change_bit() is atomic and may not be reordered. It may be - * reordered on other architectures than x86. - * 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 unsigned long *addr) -{ - __asm__ __volatile__( LOCK_PREFIX - "btcl %1,%0" - :"+m" (ADDR) - :"Ir" (nr)); -} - -/** - * test_and_set_bit - Set a bit and return its old value - * @nr: Bit to set - * @addr: Address to count from - * - * This operation is atomic and cannot be reordered. - * It may be reordered on other architectures than x86. - * It also implies a memory barrier. - */ -static inline int test_and_set_bit(int nr, volatile unsigned long *addr) -{ - int oldbit; - - __asm__ __volatile__( LOCK_PREFIX - "btsl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),"+m" (ADDR) - :"Ir" (nr) : "memory"); - return oldbit; -} - -/** - * test_and_set_bit_lock - Set a bit and return its old value for lock - * @nr: Bit to set - * @addr: Address to count from - * - * This is the same as test_and_set_bit on x86. - */ -static inline int test_and_set_bit_lock(int nr, volatile unsigned long *addr) -{ - return test_and_set_bit(nr, addr); -} - -/** - * __test_and_set_bit - Set a bit and return its old value - * @nr: Bit to set - * @addr: Address to count from - * - * This operation is non-atomic and can be reordered. - * 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 unsigned long *addr) -{ - int oldbit; - - __asm__( - "btsl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),"+m" (ADDR) - :"Ir" (nr)); - return oldbit; -} - -/** - * test_and_clear_bit - Clear a bit and return its old value - * @nr: Bit to clear - * @addr: Address to count from - * - * This operation is atomic and cannot be reordered. - * It can be reorderdered on other architectures other than x86. - * It also implies a memory barrier. - */ -static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) -{ - int oldbit; - - __asm__ __volatile__( LOCK_PREFIX - "btrl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),"+m" (ADDR) - :"Ir" (nr) : "memory"); - return oldbit; -} - -/** - * __test_and_clear_bit - Clear a bit and return its old value - * @nr: Bit to clear - * @addr: Address to count from - * - * This operation is non-atomic and can be reordered. - * 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 unsigned long *addr) -{ - int oldbit; - - __asm__( - "btrl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),"+m" (ADDR) - :"Ir" (nr)); - return oldbit; -} - -/* WARNING: non atomic and it can be reordered! */ -static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) -{ - int oldbit; - - __asm__ __volatile__( - "btcl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),"+m" (ADDR) - :"Ir" (nr) : "memory"); - return oldbit; -} - -/** - * test_and_change_bit - Change a bit and return its old value - * @nr: Bit to change - * @addr: Address to count from - * - * This operation is atomic and cannot be reordered. - * It also implies a memory barrier. - */ -static inline int test_and_change_bit(int nr, volatile unsigned long *addr) -{ - int oldbit; - - __asm__ __volatile__( LOCK_PREFIX - "btcl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),"+m" (ADDR) - :"Ir" (nr) : "memory"); - return oldbit; -} - -#if 0 /* Fool kernel-doc since it doesn't do macros yet */ -/** - * test_bit - Determine whether a bit is set - * @nr: bit number to test - * @addr: Address to start counting from - */ -static int test_bit(int nr, const volatile void *addr); -#endif - -static __always_inline int constant_test_bit(int nr, const volatile unsigned long *addr) -{ - return ((1UL << (nr & 31)) & (addr[nr >> 5])) != 0; -} - -static inline int variable_test_bit(int nr, const volatile unsigned long *addr) -{ - int oldbit; - - __asm__ __volatile__( - "btl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit) - :"m" (ADDR),"Ir" (nr)); - return oldbit; -} - -#define test_bit(nr, addr) \ - (__builtin_constant_p(nr) ? \ - constant_test_bit((nr), (addr)) : \ - variable_test_bit((nr), (addr))) - -#undef ADDR - /** * find_first_zero_bit - find the first zero bit in a memory region * @addr: The address to start the search at diff --git a/include/asm-x86/bitops_64.h b/include/asm-x86/bitops_64.h index 766bcc0..48adbf5 100644 --- a/include/asm-x86/bitops_64.h +++ b/include/asm-x86/bitops_64.h @@ -5,303 +5,6 @@ * Copyright 1992, Linus Torvalds. */ -#ifndef _LINUX_BITOPS_H -#error only <linux/bitops.h> can be included directly -#endif - -#include <asm/alternative.h> - -#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) -#else -#define ADDR "+m" (*(volatile long *) addr) -#endif - -/** - * set_bit - Atomically set a bit in memory - * @nr: the bit to set - * @addr: the address to start counting from - * - * This function is atomic and may not be reordered. See __set_bit() - * if you do not require the atomic guarantees. - * 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) -{ - __asm__ __volatile__( LOCK_PREFIX - "btsl %1,%0" - :ADDR - :"dIr" (nr) : "memory"); -} - -/** - * __set_bit - Set a bit in memory - * @nr: the bit to set - * @addr: the address to start counting from - * - * Unlike set_bit(), this function is non-atomic and may be reordered. - * 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) -{ - __asm__ volatile( - "btsl %1,%0" - :ADDR - :"dIr" (nr) : "memory"); -} - -/** - * clear_bit - Clears a bit in memory - * @nr: Bit to clear - * @addr: Address to start counting from - * - * clear_bit() is atomic and may not be reordered. However, it does - * not contain a memory barrier, so if it is used for locking purposes, - * 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) -{ - __asm__ __volatile__( LOCK_PREFIX - "btrl %1,%0" - :ADDR - :"dIr" (nr)); -} - -/* - * clear_bit_unlock - Clears a bit in memory - * @nr: Bit to clear - * @addr: Address to start counting from - * - * 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 long nr, volatile unsigned long *addr) -{ - barrier(); - clear_bit(nr, addr); -} - -static inline void __clear_bit(int nr, volatile void *addr) -{ - __asm__ __volatile__( - "btrl %1,%0" - :ADDR - :"dIr" (nr)); -} - -/* - * __clear_bit_unlock - Clears a bit in memory - * @nr: Bit to clear - * @addr: Address to start counting from - * - * __clear_bit() is non-atomic and implies release semantics before the memory - * operation. It can be used for an unlock if no other CPUs can concurrently - * modify other bits in the word. - * - * 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 long nr, volatile unsigned long *addr) -{ - barrier(); - __clear_bit(nr, addr); -} - -#define smp_mb__before_clear_bit() barrier() -#define smp_mb__after_clear_bit() barrier() - -/** - * __change_bit - Toggle a bit in memory - * @nr: the bit to change - * @addr: the address to start counting from - * - * Unlike change_bit(), this function is non-atomic and may be reordered. - * 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) -{ - __asm__ __volatile__( - "btcl %1,%0" - :ADDR - :"dIr" (nr)); -} - -/** - * change_bit - Toggle a bit in memory - * @nr: Bit to change - * @addr: Address to start counting from - * - * change_bit() is atomic and may not be reordered. - * 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) -{ - __asm__ __volatile__( LOCK_PREFIX - "btcl %1,%0" - :ADDR - :"dIr" (nr)); -} - -/** - * test_and_set_bit - Set a bit and return its old value - * @nr: Bit to set - * @addr: Address to count from - * - * 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) -{ - int oldbit; - - __asm__ __volatile__( LOCK_PREFIX - "btsl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),ADDR - :"dIr" (nr) : "memory"); - return oldbit; -} - -/** - * test_and_set_bit_lock - Set a bit and return its old value for lock - * @nr: Bit to set - * @addr: Address to count from - * - * This is the same as test_and_set_bit on x86. - */ -static inline int test_and_set_bit_lock(int nr, volatile void *addr) -{ - return test_and_set_bit(nr, addr); -} - -/** - * __test_and_set_bit - Set a bit and return its old value - * @nr: Bit to set - * @addr: Address to count from - * - * This operation is non-atomic and can be reordered. - * 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) -{ - int oldbit; - - __asm__( - "btsl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),ADDR - :"dIr" (nr)); - return oldbit; -} - -/** - * test_and_clear_bit - Clear a bit and return its old value - * @nr: Bit to clear - * @addr: Address to count from - * - * 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) -{ - int oldbit; - - __asm__ __volatile__( LOCK_PREFIX - "btrl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),ADDR - :"dIr" (nr) : "memory"); - return oldbit; -} - -/** - * __test_and_clear_bit - Clear a bit and return its old value - * @nr: Bit to clear - * @addr: Address to count from - * - * This operation is non-atomic and can be reordered. - * 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) -{ - int oldbit; - - __asm__( - "btrl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),ADDR - :"dIr" (nr)); - return oldbit; -} - -/* WARNING: non atomic and it can be reordered! */ -static inline int __test_and_change_bit(int nr, volatile void *addr) -{ - int oldbit; - - __asm__ __volatile__( - "btcl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),ADDR - :"dIr" (nr) : "memory"); - return oldbit; -} - -/** - * test_and_change_bit - Change a bit and return its old value - * @nr: Bit to change - * @addr: Address to count from - * - * 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) -{ - int oldbit; - - __asm__ __volatile__( LOCK_PREFIX - "btcl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit),ADDR - :"dIr" (nr) : "memory"); - return oldbit; -} - -#if 0 /* Fool kernel-doc since it doesn't do macros yet */ -/** - * test_bit - Determine whether a bit is set - * @nr: bit number to test - * @addr: Address to start counting from - */ -static int test_bit(int nr, const volatile void *addr); -#endif - -static inline int constant_test_bit(int nr, const volatile void *addr) -{ - return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0; -} - -static inline int variable_test_bit(int nr, volatile const void *addr) -{ - int oldbit; - - __asm__ __volatile__( - "btl %2,%1\n\tsbbl %0,%0" - :"=r" (oldbit) - :"m" (*(volatile long *)addr),"dIr" (nr)); - return oldbit; -} - -#define test_bit(nr,addr) \ -(__builtin_constant_p(nr) ? \ - constant_test_bit((nr),(addr)) : \ - variable_test_bit((nr),(addr))) - -#undef ADDR - extern long find_first_zero_bit(const unsigned long *addr, unsigned long size); extern long find_next_zero_bit(const unsigned long *addr, long size, long offset); extern long find_first_bit(const unsigned long *addr, unsigned long size); |
