diff options
Diffstat (limited to 'include/asm-x86/bitops_32.h')
| -rw-r--r-- | include/asm-x86/bitops_32.h | 324 |
1 files changed, 8 insertions, 316 deletions
diff --git a/include/asm-x86/bitops_32.h b/include/asm-x86/bitops_32.h index 0b40f6d..e4d75fc 100644 --- a/include/asm-x86/bitops_32.h +++ b/include/asm-x86/bitops_32.h @@ -5,320 +5,12 @@ * 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 * @size: The maximum size to search * - * Returns the bit-number of the first zero bit, not the number of the byte + * Returns the bit number of the first zero bit, not the number of the byte * containing a bit. */ static inline int find_first_zero_bit(const unsigned long *addr, unsigned size) @@ -348,7 +40,7 @@ static inline int find_first_zero_bit(const unsigned long *addr, unsigned size) /** * find_next_zero_bit - find the first zero bit in a memory region * @addr: The address to base the search on - * @offset: The bitnumber to start searching at + * @offset: The bit number to start searching at * @size: The maximum size to search */ int find_next_zero_bit(const unsigned long *addr, int size, int offset); @@ -372,7 +64,7 @@ static inline unsigned long __ffs(unsigned long word) * @addr: The address to start the search at * @size: The maximum size to search * - * Returns the bit-number of the first set bit, not the number of the byte + * Returns the bit number of the first set bit, not the number of the byte * containing a bit. */ static inline unsigned find_first_bit(const unsigned long *addr, unsigned size) @@ -391,7 +83,7 @@ static inline unsigned find_first_bit(const unsigned long *addr, unsigned size) /** * find_next_bit - find the first set bit in a memory region * @addr: The address to base the search on - * @offset: The bitnumber to start searching at + * @offset: The bit number to start searching at * @size: The maximum size to search */ int find_next_bit(const unsigned long *addr, int size, int offset); @@ -460,10 +152,10 @@ static inline int fls(int x) #include <asm-generic/bitops/ext2-non-atomic.h> -#define ext2_set_bit_atomic(lock,nr,addr) \ - test_and_set_bit((nr),(unsigned long*)addr) -#define ext2_clear_bit_atomic(lock,nr, addr) \ - test_and_clear_bit((nr),(unsigned long*)addr) +#define ext2_set_bit_atomic(lock, nr, addr) \ + test_and_set_bit((nr), (unsigned long *)addr) +#define ext2_clear_bit_atomic(lock, nr, addr) \ + test_and_clear_bit((nr), (unsigned long *)addr) #include <asm-generic/bitops/minix.h> |
