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#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);

#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 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 */