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#ifndef _ALPHA_BITOPS_H

#define _ALPHA_BITOPS_H

/*

 * Copyright 1994, 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 64 is the LSB of (addr+1).

 */

extern __inline__ unsigned long set_bit(unsigned long nr, void * addr)

{

        unsigned long oldbit;

        unsigned long temp;

        unsigned int * m = ((unsigned int *) addr) + (nr >> 5);

        __asm__ __volatile__(

                "\n1:\t"

                "ldl_l %0,%1\n\t"

                "and %0,%3,%2\n\t"

                "bne %2,2f\n\t"

                "xor %0,%3,%0\n\t"

                "stl_c %0,%1\n\t"

                "beq %0,1b\n"

                "2:"

                :"=&r" (temp),

                 "=m" (*m),

                 "=&r" (oldbit)

                :"Ir" (1UL << (nr & 31)),

                 "m" (*m));

        return oldbit != 0;

}

extern __inline__ unsigned long clear_bit(unsigned long nr, void * addr)

{

        unsigned long oldbit;

        unsigned long temp;

        unsigned int * m = ((unsigned int *) addr) + (nr >> 5);

        __asm__ __volatile__(

                "\n1:\t"

                "ldl_l %0,%1\n\t"

                "and %0,%3,%2\n\t"

                "beq %2,2f\n\t"

                "xor %0,%3,%0\n\t"

                "stl_c %0,%1\n\t"

                "beq %0,1b\n"

                "2:"

                :"=&r" (temp),

                 "=m" (*m),

                 "=&r" (oldbit)

                :"Ir" (1UL << (nr & 31)),

                 "m" (*m));

        return oldbit != 0;

}

extern __inline__ unsigned long change_bit(unsigned long nr, void * addr)

{

        unsigned long oldbit;

        unsigned long temp;

        unsigned int * m = ((unsigned int *) addr) + (nr >> 5);

        __asm__ __volatile__(

                "\n1:\t"

                "ldl_l %0,%1\n\t"

                "and %0,%3,%2\n\t"

                "xor %0,%3,%0\n\t"

                "stl_c %0,%1\n\t"

                "beq %0,1b\n"

                :"=&r" (temp),

                 "=m" (*m),

                 "=&r" (oldbit)

                :"Ir" (1UL << (nr & 31)),

                 "m" (*m));

        return oldbit != 0;

}

extern __inline__ unsigned long test_bit(int nr, const void * addr)

{

        return 1UL & (((const int *) addr)[nr >> 5] >> (nr & 31));

}

/*

 * ffz = Find First Zero in word. Undefined if no zero exists,

 * so code should check against ~0UL first..

 *

 * Do a binary search on the bits.  Due to the nature of large

 * constants on the alpha, it is worthwhile to split the search.

 */

extern inline unsigned long ffz_b(unsigned long x)

{

        unsigned long sum = 0;

        x = ~x & -~x;           /* set first 0 bit, clear others */

        if (x & 0xF0) sum += 4;

        if (x & 0xCC) sum += 2;

        if (x & 0xAA) sum += 1;

        return sum;

}

extern inline unsigned long ffz(unsigned long word)

{

        unsigned long bits, qofs, bofs;

        __asm__("cmpbge %1,%2,%0" : "=r"(bits) : "r"(word), "r"(~0UL));

        qofs = ffz_b(bits);

        __asm__("extbl %1,%2,%0" : "=r"(bits) : "r"(word), "r"(qofs));

        bofs = ffz_b(bits);

        return qofs*8 + bofs;

}

/*

 * Find next zero bit in a bitmap reasonably efficiently..

 */

extern inline unsigned long find_next_zero_bit(void * addr, unsigned long size, unsigned long offset)

{

        unsigned long * p = ((unsigned long *) addr) + (offset >> 6);

        unsigned long result = offset & ~63UL;

        unsigned long tmp;

        if (offset >= size)

                return size;

        size -= result;

        offset &= 63UL;

        if (offset) {

                tmp = *(p++);

                tmp |= ~0UL >> (64-offset);

                if (size < 64)

                        goto found_first;

                if (~tmp)

                        goto found_middle;

                size -= 64;

                result += 64;

        }

        while (size & ~63UL) {

                if (~(tmp = *(p++)))

                        goto found_middle;

                result += 64;

                size -= 64;

        }

        if (!size)

                return result;

        tmp = *p;

found_first:

        tmp |= ~0UL << size;

found_middle:

        return result + ffz(tmp);

}

/*

 * The optimizer actually does good code for this case..

 */

#define find_first_zero_bit(addr, size) \

        find_next_zero_bit((addr), (size), 0)

#endif /* _ALPHA_BITOPS_H */