/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) 1994 - 1997, 1999, 2000  Ralf Baechle (ralf@gnu.org)
 * Copyright (c) 2000  Silicon Graphics, Inc.
 */
#ifndef _ASM_BITOPS_H
#define _ASM_BITOPS_H

#include <linux/types.h>
#include <asm/byteorder.h>              /* sigh ... */

#ifdef __KERNEL__

#include <asm/sgidefs.h>
#include <asm/system.h>
#include <linux/config.h>

/*
 * clear_bit() doesn't provide any barrier for the compiler.
 */
#define smp_mb__before_clear_bit()      barrier()
#define smp_mb__after_clear_bit()       barrier()

/*
 * Only disable interrupt for kernel mode stuff to keep usermode stuff
 * that dares to use kernel include files alive.
 */
#define __bi_flags unsigned long flags
#define __bi_cli() __cli()
#define __bi_save_flags(x) __save_flags(x)
#define __bi_save_and_cli(x) __save_and_cli(x)
#define __bi_restore_flags(x) __restore_flags(x)
#else
#define __bi_flags
#define __bi_cli()
#define __bi_save_flags(x)
#define __bi_save_and_cli(x)
#define __bi_restore_flags(x)
#endif /* __KERNEL__ */

#ifdef CONFIG_CPU_HAS_LLSC

#include <asm/mipsregs.h>

/*
 * These functions for MIPS ISA > 1 are interrupt and SMP proof and
 * interrupt friendly
 */

/*
 * 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)
{
        unsigned long *m = ((unsigned long *) addr) + (nr >> 5);
        unsigned long temp;

        __asm__ __volatile__(
                "1:\tll\t%0, %1\t\t# set_bit\n\t"
                "or\t%0, %2\n\t"
                "sc\t%0, %1\n\t"
                "beqz\t%0, 1b"
                : "=&r" (temp), "=m" (*m)
                : "ir" (1UL << (nr & 0x1f)), "m" (*m));
}

/*
 * __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)
{
        unsigned long * m = ((unsigned long *) addr) + (nr >> 5);

        *m |= 1UL << (nr & 31);
}
#define PLATFORM__SET_BIT

/*
 * 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)
{
        unsigned long *m = ((unsigned long *) addr) + (nr >> 5);
        unsigned long temp;

        __asm__ __volatile__(
                "1:\tll\t%0, %1\t\t# clear_bit\n\t"
                "and\t%0, %2\n\t"
                "sc\t%0, %1\n\t"
                "beqz\t%0, 1b\n\t"
                : "=&r" (temp), "=m" (*m)
                : "ir" (~(1UL << (nr & 0x1f))), "m" (*m));
}

/*
 * 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)
{
        unsigned long *m = ((unsigned long *) addr) + (nr >> 5);
        unsigned long temp;

        __asm__ __volatile__(
                "1:\tll\t%0, %1\t\t# change_bit\n\t"
                "xor\t%0, %2\n\t"
                "sc\t%0, %1\n\t"
                "beqz\t%0, 1b"
                : "=&r" (temp), "=m" (*m)
                : "ir" (1UL << (nr & 0x1f)), "m" (*m));
}

/*
 * __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)
{
        unsigned long * m = ((unsigned long *) addr) + (nr >> 5);

        *m ^= 1UL << (nr & 31);
}

/*
 * 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)
{
        unsigned long *m = ((unsigned long *) addr) + (nr >> 5);
        unsigned long temp, res;

        __asm__ __volatile__(
                ".set\tnoreorder\t\t# test_and_set_bit\n"
                "1:\tll\t%0, %1\n\t"
                "or\t%2, %0, %3\n\t"
                "sc\t%2, %1\n\t"
                "beqz\t%2, 1b\n\t"
                " and\t%2, %0, %3\n\t"
                ".set\treorder"
                : "=&r" (temp), "=m" (*m), "=&r" (res)
                : "r" (1UL << (nr & 0x1f)), "m" (*m)
                : "memory");

        return res != 0;
}

/*
 * __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 mask, retval;
        volatile int *a = addr;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        retval = (mask & *a) != 0;
        *a |= mask;

        return retval;
}

/*
 * 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)
{
        unsigned long *m = ((unsigned long *) addr) + (nr >> 5);
        unsigned long temp, res;

        __asm__ __volatile__(
                ".set\tnoreorder\t\t# test_and_clear_bit\n"
                "1:\tll\t%0, %1\n\t"
                "or\t%2, %0, %3\n\t"
                "xor\t%2, %3\n\t"
                "sc\t%2, %1\n\t"
                "beqz\t%2, 1b\n\t"
                " and\t%2, %0, %3\n\t"
                ".set\treorder"
                : "=&r" (temp), "=m" (*m), "=&r" (res)
                : "r" (1UL << (nr & 0x1f)), "m" (*m)
                : "memory");

        return res != 0;
}

/*
 * __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     mask, retval;
        volatile int    *a = addr;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        retval = (mask & *a) != 0;
        *a &= ~mask;

        return retval;
}

/*
 * 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)
{
        unsigned long *m = ((unsigned long *) addr) + (nr >> 5);
        unsigned long temp, res;

        __asm__ __volatile__(
                ".set\tnoreorder\t\t# test_and_change_bit\n"
                "1:\tll\t%0, %1\n\t"
                "xor\t%2, %0, %3\n\t"
                "sc\t%2, %1\n\t"
                "beqz\t%2, 1b\n\t"
                " and\t%2, %0, %3\n\t"
                ".set\treorder"
                : "=&r" (temp), "=m" (*m), "=&r" (res)
                : "r" (1UL << (nr & 0x1f)), "m" (*m)
                : "memory");

        return res != 0;
}

/*
 * __test_and_change_bit - Change 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_change_bit(int nr, volatile void * addr)
{
        int     mask, retval;
        volatile int    *a = addr;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        retval = (mask & *a) != 0;
        *a ^= mask;

        return retval;
}

#else /* MIPS I */

/*
 * 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)
{
        int     mask;
        volatile int    *a = addr;
        __bi_flags;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        __bi_save_and_cli(flags);
        *a |= mask;
        __bi_restore_flags(flags);
}

/*
 * __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)
{
        int     mask;
        volatile int    *a = addr;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        *a |= mask;
}

/*
 * 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)
{
        int     mask;
        volatile int    *a = addr;
        __bi_flags;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        __bi_save_and_cli(flags);
        *a &= ~mask;
        __bi_restore_flags(flags);
}

/*
 * 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)
{
        int     mask;
        volatile int    *a = addr;
        __bi_flags;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        __bi_save_and_cli(flags);
        *a ^= mask;
        __bi_restore_flags(flags);
}

/*
 * __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)
{
        unsigned long * m = ((unsigned long *) addr) + (nr >> 5);

        *m ^= 1UL << (nr & 31);
}

/*
 * 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     mask, retval;
        volatile int    *a = addr;
        __bi_flags;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        __bi_save_and_cli(flags);
        retval = (mask & *a) != 0;
        *a |= mask;
        __bi_restore_flags(flags);

        return retval;
}

/*
 * __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     mask, retval;
        volatile int    *a = addr;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        retval = (mask & *a) != 0;
        *a |= mask;

        return retval;
}

/*
 * 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     mask, retval;
        volatile int    *a = addr;
        __bi_flags;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        __bi_save_and_cli(flags);
        retval = (mask & *a) != 0;
        *a &= ~mask;
        __bi_restore_flags(flags);

        return retval;
}

/*
 * __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     mask, retval;
        volatile int    *a = addr;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        retval = (mask & *a) != 0;
        *a &= ~mask;

        return retval;
}

/*
 * 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     mask, retval;
        volatile int    *a = addr;
        __bi_flags;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        __bi_save_and_cli(flags);
        retval = (mask & *a) != 0;
        *a ^= mask;
        __bi_restore_flags(flags);

        return retval;
}

/*
 * __test_and_change_bit - Change 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_change_bit(int nr, volatile void * addr)
{
        int     mask, retval;
        volatile int    *a = addr;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        retval = (mask & *a) != 0;
        *a ^= mask;

        return retval;
}

#undef __bi_flags
#undef __bi_cli
#undef __bi_save_flags
#undef __bi_restore_flags

#endif /* MIPS I */

/*
 * test_bit - Determine whether a bit is set
 * @nr: bit number to test
 * @addr: Address to start counting from
 */
static __inline__ int test_bit(int nr, volatile void *addr)
{
        return ((1UL << (nr & 31)) & (((const unsigned int *) addr)[nr >> 5])) != 0;
}

#ifndef __MIPSEB__

/* Little endian versions. */

/*
 * 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)
{
        unsigned long dummy;
        int res;

        if (!size)
                return 0;

        __asm__ (".set\tnoreorder\n\t"
                ".set\tnoat\n"
                "1:\tsubu\t$1,%6,%0\n\t"
                "blez\t$1,2f\n\t"
                "lw\t$1,(%5)\n\t"
                "addiu\t%5,4\n\t"
#if (_MIPS_ISA == _MIPS_ISA_MIPS2 ) || (_MIPS_ISA == _MIPS_ISA_MIPS3 ) || \
    (_MIPS_ISA == _MIPS_ISA_MIPS4 ) || (_MIPS_ISA == _MIPS_ISA_MIPS5 ) || \
    (_MIPS_ISA == _MIPS_ISA_MIPS32) || (_MIPS_ISA == _MIPS_ISA_MIPS64)
                "beql\t%1,$1,1b\n\t"
                "addiu\t%0,32\n\t"
#else
                "addiu\t%0,32\n\t"
                "beq\t%1,$1,1b\n\t"
                "nop\n\t"
                "subu\t%0,32\n\t"
#endif
#ifdef __MIPSEB__
#error "Fix this for big endian"
#endif /* __MIPSEB__ */
                "li\t%1,1\n"
                "1:\tand\t%2,$1,%1\n\t"
                "beqz\t%2,2f\n\t"
                "sll\t%1,%1,1\n\t"
                "bnez\t%1,1b\n\t"
                "add\t%0,%0,1\n\t"
                ".set\tat\n\t"
                ".set\treorder\n"
                "2:"
                : "=r" (res), "=r" (dummy), "=r" (addr)
                : "0" ((signed int) 0), "1" ((unsigned int) 0xffffffff),
                  "2" (addr), "r" (size)
                : "$1");

        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 int *p = ((unsigned int *) addr) + (offset >> 5);
        int set = 0, bit = offset & 31, res;
        unsigned long dummy;

        if (bit) {
                /*
                 * Look for zero in first byte
                 */
#ifdef __MIPSEB__
#error "Fix this for big endian byte order"
#endif
                __asm__(".set\tnoreorder\n\t"
                        ".set\tnoat\n"
                        "1:\tand\t$1,%4,%1\n\t"
                        "beqz\t$1,1f\n\t"
                        "sll\t%1,%1,1\n\t"
                        "bnez\t%1,1b\n\t"
                        "addiu\t%0,1\n\t"
                        ".set\tat\n\t"
                        ".set\treorder\n"
                        "1:"
                        : "=r" (set), "=r" (dummy)
                        : "0" (0), "1" (1 << bit), "r" (*p)
                        : "$1");
                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 int *) addr));
        return offset + set + res;
}

#endif /* !(__MIPSEB__) */

/*
 * 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)
{
        unsigned int    __res;
        unsigned int    mask = 1;

        __asm__ (
                ".set\tnoreorder\n\t"
                ".set\tnoat\n\t"
                "move\t%0,$0\n"
                "1:\tand\t$1,%2,%1\n\t"
                "beqz\t$1,2f\n\t"
                "sll\t%1,1\n\t"
                "bnez\t%1,1b\n\t"
                "addiu\t%0,1\n\t"
                ".set\tat\n\t"
                ".set\treorder\n"
                "2:\n\t"
                : "=&r" (__res), "=r" (mask)
                : "r" (word), "1" (mask)
                : "$1");

        return __res;
}

#ifdef __KERNEL__

/*
 * 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 __MIPSEB__
/*
 * 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);
        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.
 */

#if 0 /* Fool kernel-doc since it doesn't do macros yet */
/*
 * 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 int find_first_zero_bit (void *addr, unsigned size);
#endif

#define find_first_zero_bit(addr, size) \
        find_next_zero_bit((addr), (size), 0)

#endif /* (__MIPSEB__) */

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

#ifdef __MIPSEB__
static __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_and_cli(flags);
        retval = (mask & *ADDR) != 0;
        *ADDR |= mask;
        restore_flags(flags);
        return retval;
}

static __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_and_cli(flags);
        retval = (mask & *ADDR) != 0;
        *ADDR &= ~mask;
        restore_flags(flags);
        return retval;
}

static __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)

static __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) {
                /* We hold the little endian value in tmp, but then the
                 * shift is illegal. So we could keep a big endian value
                 * in tmp, like this:
                 *
                 * tmp = __swab32(*(p++));
                 * tmp |= ~0UL >> (32-offset);
                 *
                 * but this would decrease preformance, so we change the
                 * shift:
                 */
                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:
        /* tmp is little endian, so we would have to swab the shift,
         * see above. But then we have to swab tmp below for ffz, so
         * we might as well do this here.
         */
        return result + ffz(__swab32(tmp) | (~0UL << size));
found_middle:
        return result + ffz(__swab32(tmp));
}
#else /* !(__MIPSEB__) */

/* Native ext2 byte ordering, just collapse using defines. */
#define ext2_set_bit(nr, addr) test_and_set_bit((nr), (addr))
#define ext2_clear_bit(nr, addr) test_and_clear_bit((nr), (addr))
#define ext2_test_bit(nr, addr) test_bit((nr), (addr))
#define ext2_find_first_zero_bit(addr, size) find_first_zero_bit((addr), (size))
#define ext2_find_next_zero_bit(addr, size, offset) \
                find_next_zero_bit((addr), (size), (offset))

#endif /* !(__MIPSEB__) */

/*
 * Bitmap functions for the minix filesystem.
 * FIXME: These assume that Minix uses the native byte/bitorder.
 * This limits the Minix filesystem's value for data exchange very much.
 */
#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 /* _ASM_BITOPS_H */