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#ifndef _ASM_GENERIC_BITOPS_H_

#define _ASM_GENERIC_BITOPS_H_

#ifdef __KERNEL__

#include <asm/system.h>

#endif

/*

 * For the benefit of those who are trying to port Linux to another

 * architecture, here are some C-language equivalents.  You should

 * recode these in the native assembly language, if at all possible.

 * To guarantee atomicity, these routines call cli() and sti() to

 * disable interrupts while they operate.  (You have to provide inline

 * routines to cli() and sti().)

 *

 * Also note, these routines assume that you have 32 bit integers.

 * You will have to change this if you are trying to port Linux to the

 * Alpha architecture or to a Cray.  :-)

 *

 * C language equivalents written by Theodore Ts'o, 9/26/92

 */

extern __inline__ int set_bit(int nr, void * a)

{

        int     * addr = a;

        int     mask, retval;

        unsigned long flags;

        addr += nr >> 5;

        mask = 1 << (nr & 0x1f);

        save_flags(flags); cli();

        retval = (mask & *addr) != 0;

        *addr |= mask;

        restore_flags(flags);

        return retval;

}

extern __inline__ int clear_bit(int nr, void * a)

{

        int     * addr = a;

        int     mask, retval;

        unsigned long flags;

        addr += nr >> 5;

        mask = 1 << (nr & 0x1f);

        save_flags(flags); cli();

        retval = (mask & *addr) != 0;

        *addr &= ~mask;

        restore_flags(flags);

        return retval;

}

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

{

        int mask, flags;

        unsigned long *ADDR = (unsigned long *) addr;

        unsigned long oldbit;

        ADDR += nr >> 5;

        mask = 1 << (nr & 31);

        save_flags(flags); cli();

        oldbit = (mask & *ADDR);

        *ADDR ^= mask;

        restore_flags(flags);

        return oldbit != 0;

}

extern __inline__ int test_bit(int nr, void * a)

{

        int     * addr = a;

        int     mask;

        addr += nr >> 5;

        mask = 1 << (nr & 0x1f);

        return ((mask & *addr) != 0);

}

/* The easy/cheese version for now. */

extern __inline__ unsigned long ffz(unsigned long word)

{

        unsigned long result = 0;

        while(word & 1) {

                result++;

                word >>= 1;

        }

        return result;

}

/* find_next_zero_bit() finds the first zero bit in a bit string of length

 * 'size' bits, starting the search at bit 'offset'. This is largely based

 * on Linus's ALPHA routines, which are pretty portable BTW.

 */

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

{

        unsigned long *p = ((unsigned long *) addr) + (offset >> 5);

        unsigned long result = offset & ~31UL;

        unsigned long tmp;

        if (offset >= size)

                return size;

        size -= result;

        offset &= 31UL;

        if (offset) {

                tmp = *(p++);

                tmp |= ~0UL >> (32-offset);

                if (size < 32)

                        goto found_first;

                if (~tmp)

                        goto found_middle;

                size -= 32;

                result += 32;

        }

        while (size & ~31UL) {

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

                        goto found_middle;

                result += 32;

                size -= 32;

        }

        if (!size)

                return result;

        tmp = *p;

found_first:

        tmp |= ~0UL >> size;

found_middle:

        return result + ffz(tmp);

}

/* Linus sez that gcc can optimize the following correctly, we'll see if this

 * holds on the Sparc as it does for the ALPHA.

 */

#define find_first_zero_bit(addr, size) \

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

/* Now for the ext2 filesystem bit operations and helper routines. */

extern __inline__ int ext2_set_bit(int nr,void * addr)

{

        int             mask, retval, flags;

        unsigned char   *ADDR = (unsigned char *) addr;

        ADDR += nr >> 3;

        mask = 1 << (nr & 0x07);

        save_flags(flags); cli();

        retval = (mask & *ADDR) != 0;

        *ADDR |= mask;

        restore_flags(flags);

        return retval;

}

extern __inline__ int ext2_clear_bit(int nr, void * addr)

{

        int             mask, retval, flags;

        unsigned char   *ADDR = (unsigned char *) addr;

        ADDR += nr >> 3;

        mask = 1 << (nr & 0x07);

        save_flags(flags); cli();

        retval = (mask & *ADDR) != 0;

        *ADDR &= ~mask;

        restore_flags(flags);

        return retval;

}

extern __inline__ int ext2_test_bit(int nr, const void * addr)

{

        int                     mask;

        const unsigned char     *ADDR = (const unsigned char *) addr;

        ADDR += nr >> 3;

        mask = 1 << (nr & 0x07);

        return ((mask & *ADDR) != 0);

}

#define ext2_find_first_zero_bit(addr, size) \

        ext2_find_next_zero_bit((addr), (size), 0)

extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)

{

        unsigned long *p = ((unsigned long *) addr) + (offset >> 5);

        unsigned long result = offset & ~31UL;

        unsigned long tmp;

        if (offset >= size)

                return size;

        size -= result;

        offset &= 31UL;

        if(offset) {

                tmp = *(p++);

                tmp |= ~0UL << (32-offset);

                if(size < 32)

                        goto found_first;

                if(~tmp)

                        goto found_middle;

                size -= 32;

                result += 32;

        }

        while(size & ~31UL) {

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

                        goto found_middle;

                result += 32;

                size -= 32;

        }

        if(!size)

                return result;

        tmp = *p;

found_first:

        tmp |= ~0UL << size;

found_middle:

        tmp = ((tmp>>24) | ((tmp>>8)&0xff00) | ((tmp<<8)&0xff0000) | (tmp<<24));

        return result + ffz(tmp);

}

#define __ext2_set_bit ext2_set_bit

#define __ext2_clear_bit ext2_clear_bit

extern __inline__ int __ext2_test_bit(int nr, __const__ void * addr)

{

        int                     mask;

        __const__ unsigned char *ADDR = (__const__ unsigned char *) addr;

        ADDR += nr >> 3;

        mask = 1 << (nr & 0x07);

        return ((mask & *ADDR) != 0);

}

extern __inline__ unsigned short __swab16(unsigned short value)

{

        return ((value >> 8) | (value << 8));

}

extern __inline__ unsigned long __swab32(unsigned long value)

{

        return ((value >> 24) | ((value >> 8) & 0xff00) |

               ((value << 8) & 0xff0000) | (value << 24));

}

#define __ext2_find_first_zero_bit(addr, size) \

        __ext2_find_next_zero_bit((addr), (size), 0)

extern __inline__ unsigned long __ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)

{

        unsigned long *p = ((unsigned long *) addr) + (offset >> 5);

        unsigned long result = offset & ~31UL;

        unsigned long tmp;

        if (offset >= size)

                return size;

        size -= result;

        offset &= 31UL;

        if(offset) {

                tmp = *(p++);

                tmp |= __swab32(~0UL >> (32-offset));

                if(size < 32)

                        goto found_first;

                if(~tmp)

                        goto found_middle;

                size -= 32;

                result += 32;

        }

        while(size & ~31UL) {

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

                        goto found_middle;

                result += 32;

                size -= 32;

        }

        if(!size)

                return result;

        tmp = *p;

found_first:

        return result + ffz(__swab32(tmp) | (~0UL << size));

found_middle:

        return result + ffz(__swab32(tmp));

}

#endif /* _ASM_GENERIC_BITOPS_H */