#ifndef _I386_BITOPS_H#define _I386_BITOPS_H/* * Copyright 1992, Linus Torvalds. *//* * 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). */#ifdef CONFIG_SMP#define LOCK_PREFIX "lock ; "#else#define LOCK_PREFIX ""#endif#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 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"		:"=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 void * 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 void * addr){	__asm__ __volatile__( LOCK_PREFIX		"btrl %1,%0"		:"=m" (ADDR)		:"Ir" (nr));}#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 set * @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"		:"=m" (ADDR)		:"Ir" (nr));}/** * change_bit - Toggle a bit in memory * @nr: Bit to clear * @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"		:"=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 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),"=m" (ADDR)		:"Ir" (nr) : "memory");	return oldbit;}/** * __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),"=m" (ADDR)		:"Ir" (nr));	return oldbit;}/** * test_and_clear_bit - Clear 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_clear_bit(int nr, volatile void * 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 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_clear_bit(int nr, volatile void * 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 void * 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 new 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_change_bit(int nr, volatile void * 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);#endifstatic __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 void * 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)))/** * 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 * containing a bit. */static __inline__ int find_first_zero_bit(void * addr, unsigned size){	int d0, d1, d2;	int res;	if (!size)		return 0;	/* This looks at memory. Mark it volatile to tell gcc not to move it around */	__asm__ __volatile__(		"movl $-1,%%eax\n\t"		"xorl %%edx,%%edx\n\t"		"repe; scasl\n\t"		"je 1f\n\t"		"xorl -4(%%edi),%%eax\n\t"		"subl $4,%%edi\n\t"		"bsfl %%eax,%%edx\n"		"1:\tsubl %%ebx,%%edi\n\t"		"shll $3,%%edi\n\t"		"addl %%edi,%%edx"		:"=d" (res), "=&c" (d0), "=&D" (d1), "=&a" (d2)		:"1" ((size + 31) >> 5), "2" (addr), "b" (addr));	return res;}/** * 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 * @size: The maximum size to search */static __inline__ int find_next_zero_bit (void * addr, int size, int offset){	unsigned long * p = ((unsigned long *) addr) + (offset >> 5);	int set = 0, bit = offset & 31, res;	if (bit) {		/*		 * Look for zero in first byte		 */		__asm__("bsfl %1,%0\n\t"			"jne 1f\n\t"			"movl $32, %0\n"			"1:"			: "=r" (set)			: "r" (~(*p >> bit)));		if (set < (32 - bit))			return set + offset;		set = 32 - bit;		p++;	}	/*	 * No zero yet, search remaining full bytes for a zero	 */	res = find_first_zero_bit (p, size - 32 * (p - (unsigned long *) addr));	return (offset + set + res);}/** * ffz - find first zero in word. * @word: The word to search * * Undefined if no zero exists, so code should check against ~0UL first. */static __inline__ unsigned long ffz(unsigned long word){	__asm__("bsfl %1,%0"		:"=r" (word)		:"r" (~word));	return word;}#ifdef __KERNEL__/** * ffs - find first bit set * @x: the word to search * * This is defined the same way as * the libc and compiler builtin ffs routines, therefore * differs in spirit from the above ffz (man ffs). */static __inline__ int ffs(int x){	int r;	__asm__("bsfl %1,%0\n\t"		"jnz 1f\n\t"		"movl $-1,%0\n"		"1:" : "=r" (r) : "g" (x));	return r+1;}/** * hweightN - returns the hamming weight of a N-bit word * @x: the word to weigh * * The Hamming Weight of a number is the total number of bits set in it. */#define hweight32(x) generic_hweight32(x)#define hweight16(x) generic_hweight16(x)#define hweight8(x) generic_hweight8(x)#endif /* __KERNEL__ */#ifdef __KERNEL__#define ext2_set_bit                 __test_and_set_bit#define ext2_clear_bit               __test_and_clear_bit#define ext2_test_bit                test_bit#define ext2_find_first_zero_bit     find_first_zero_bit#define ext2_find_next_zero_bit      find_next_zero_bit/* Bitmap functions for the minix filesystem.  */#define minix_test_and_set_bit(nr,addr) __test_and_set_bit(nr,addr)#define minix_set_bit(nr,addr) __set_bit(nr,addr)#define minix_test_and_clear_bit(nr,addr) __test_and_clear_bit(nr,addr)#define minix_test_bit(nr,addr) test_bit(nr,addr)#define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size)#endif /* __KERNEL__ */#endif /* _I386_BITOPS_H */