bitmap.c

Go to the documentation of this file.

/*
 * lib/bitmap.c
 * Helper functions for bitmap.h.
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */
#include <linux/export.h>
#include <linux/thread_info.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <asm/uaccess.h>

/*
 * bitmaps provide an array of bits, implemented using an an
 * array of unsigned longs.  The number of valid bits in a
 * given bitmap does _not_ need to be an exact multiple of
 * BITS_PER_LONG.
 *
 * The possible unused bits in the last, partially used word
 * of a bitmap are 'don't care'.  The implementation makes
 * no particular effort to keep them zero.  It ensures that
 * their value will not affect the results of any operation.
 * The bitmap operations that return Boolean (bitmap_empty,
 * for example) or scalar (bitmap_weight, for example) results
 * carefully filter out these unused bits from impacting their
 * results.
 *
 * These operations actually hold to a slightly stronger rule:
 * if you don't input any bitmaps to these ops that have some
 * unused bits set, then they won't output any set unused bits
 * in output bitmaps.
 *
 * The byte ordering of bitmaps is more natural on little
 * endian architectures.  See the big-endian headers
 * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
 * for the best explanations of this ordering.
 */

int __bitmap_empty(const unsigned long *bitmap, int bits)
{
    int k, lim = bits/BITS_PER_LONG;
    for (k = 0; k < lim; ++k)
        if (bitmap[k])
            return 0;

    if (bits % BITS_PER_LONG)
        if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
            return 0;

    return 1;
}
EXPORT_SYMBOL(__bitmap_empty);

int __bitmap_full(const unsigned long *bitmap, int bits)
{
    int k, lim = bits/BITS_PER_LONG;
    for (k = 0; k < lim; ++k)
        if (~bitmap[k])
            return 0;

    if (bits % BITS_PER_LONG)
        if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
            return 0;

    return 1;
}
EXPORT_SYMBOL(__bitmap_full);

int __bitmap_equal(const unsigned long *bitmap1,
        const unsigned long *bitmap2, int bits)
{
    int k, lim = bits/BITS_PER_LONG;
    for (k = 0; k < lim; ++k)
        if (bitmap1[k] != bitmap2[k])
            return 0;

    if (bits % BITS_PER_LONG)
        if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
            return 0;

    return 1;
}
EXPORT_SYMBOL(__bitmap_equal);

void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits)
{
    int k, lim = bits/BITS_PER_LONG;
    for (k = 0; k < lim; ++k)
        dst[k] = ~src[k];

    if (bits % BITS_PER_LONG)
        dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits);
}
EXPORT_SYMBOL(__bitmap_complement);

void __bitmap_shift_right(unsigned long *dst,
            const unsigned long *src, int shift, int bits)
{
    int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
    int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
    unsigned long mask = (1UL << left) - 1;
    for (k = 0; off + k < lim; ++k) {
        unsigned long upper, lower;

        /*
         * If shift is not word aligned, take lower rem bits of
         * word above and make them the top rem bits of result.
         */
        if (!rem || off + k + 1 >= lim)
            upper = 0;
        else {
            upper = src[off + k + 1];
            if (off + k + 1 == lim - 1 && left)
                upper &= mask;
        }
        lower = src[off + k];
        if (left && off + k == lim - 1)
            lower &= mask;
        dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem;
        if (left && k == lim - 1)
            dst[k] &= mask;
    }
    if (off)
        memset(&dst[lim - off], 0, off*sizeof(unsigned long));
}
EXPORT_SYMBOL(__bitmap_shift_right);


void __bitmap_shift_left(unsigned long *dst,
            const unsigned long *src, int shift, int bits)
{
    int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
    int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
    for (k = lim - off - 1; k >= 0; --k) {
        unsigned long upper, lower;

        /*
         * If shift is not word aligned, take upper rem bits of
         * word below and make them the bottom rem bits of result.
         */
        if (rem && k > 0)
            lower = src[k - 1];
        else
            lower = 0;
        upper = src[k];
        if (left && k == lim - 1)
            upper &= (1UL << left) - 1;
        dst[k + off] = lower  >> (BITS_PER_LONG - rem) | upper << rem;
        if (left && k + off == lim - 1)
            dst[k + off] &= (1UL << left) - 1;
    }
    if (off)
        memset(dst, 0, off*sizeof(unsigned long));
}
EXPORT_SYMBOL(__bitmap_shift_left);

int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
                const unsigned long *bitmap2, int bits)
{
    int k;
    int nr = BITS_TO_LONGS(bits);
    unsigned long result = 0;

    for (k = 0; k < nr; k++)
        result |= (dst[k] = bitmap1[k] & bitmap2[k]);
    return result != 0;
}
EXPORT_SYMBOL(__bitmap_and);

void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
                const unsigned long *bitmap2, int bits)
{
    int k;
    int nr = BITS_TO_LONGS(bits);

    for (k = 0; k < nr; k++)
        dst[k] = bitmap1[k] | bitmap2[k];
}
EXPORT_SYMBOL(__bitmap_or);

void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
                const unsigned long *bitmap2, int bits)
{
    int k;
    int nr = BITS_TO_LONGS(bits);

    for (k = 0; k < nr; k++)
        dst[k] = bitmap1[k] ^ bitmap2[k];
}
EXPORT_SYMBOL(__bitmap_xor);

int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
                const unsigned long *bitmap2, int bits)
{
    int k;
    int nr = BITS_TO_LONGS(bits);
    unsigned long result = 0;

    for (k = 0; k < nr; k++)
        result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
    return result != 0;
}
EXPORT_SYMBOL(__bitmap_andnot);

int __bitmap_intersects(const unsigned long *bitmap1,
                const unsigned long *bitmap2, int bits)
{
    int k, lim = bits/BITS_PER_LONG;
    for (k = 0; k < lim; ++k)
        if (bitmap1[k] & bitmap2[k])
            return 1;

    if (bits % BITS_PER_LONG)
        if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
            return 1;
    return 0;
}
EXPORT_SYMBOL(__bitmap_intersects);

int __bitmap_subset(const unsigned long *bitmap1,
                const unsigned long *bitmap2, int bits)
{
    int k, lim = bits/BITS_PER_LONG;
    for (k = 0; k < lim; ++k)
        if (bitmap1[k] & ~bitmap2[k])
            return 0;

    if (bits % BITS_PER_LONG)
        if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
            return 0;
    return 1;
}
EXPORT_SYMBOL(__bitmap_subset);

int __bitmap_weight(const unsigned long *bitmap, int bits)
{
    int k, w = 0, lim = bits/BITS_PER_LONG;

    for (k = 0; k < lim; k++)
        w += hweight_long(bitmap[k]);

    if (bits % BITS_PER_LONG)
        w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));

    return w;
}
EXPORT_SYMBOL(__bitmap_weight);

void bitmap_set(unsigned long *map, int start, int nr)
{
    unsigned long *p = map + BIT_WORD(start);
    const int size = start + nr;
    int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
    unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);

    while (nr - bits_to_set >= 0) {
        *p |= mask_to_set;
        nr -= bits_to_set;
        bits_to_set = BITS_PER_LONG;
        mask_to_set = ~0UL;
        p++;
    }
    if (nr) {
        mask_to_set &= BITMAP_LAST_WORD_MASK(size);
        *p |= mask_to_set;
    }
}
EXPORT_SYMBOL(bitmap_set);

void bitmap_clear(unsigned long *map, int start, int nr)
{
    unsigned long *p = map + BIT_WORD(start);
    const int size = start + nr;
    int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
    unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);

    while (nr - bits_to_clear >= 0) {
        *p &= ~mask_to_clear;
        nr -= bits_to_clear;
        bits_to_clear = BITS_PER_LONG;
        mask_to_clear = ~0UL;
        p++;
    }
    if (nr) {
        mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
        *p &= ~mask_to_clear;
    }
}
EXPORT_SYMBOL(bitmap_clear);

/*
 * bitmap_find_next_zero_area - find a contiguous aligned zero area
 * @map: The address to base the search on
 * @size: The bitmap size in bits
 * @start: The bitnumber to start searching at
 * @nr: The number of zeroed bits we're looking for
 * @align_mask: Alignment mask for zero area
 *
 * The @align_mask should be one less than a power of 2; the effect is that
 * the bit offset of all zero areas this function finds is multiples of that
 * power of 2. A @align_mask of 0 means no alignment is required.
 */
unsigned long bitmap_find_next_zero_area(unsigned long *map,
                     unsigned long size,
                     unsigned long start,
                     unsigned int nr,
                     unsigned long align_mask)
{
    unsigned long index, end, i;
again:
    index = find_next_zero_bit(map, size, start);

    /* Align allocation */
    index = __ALIGN_MASK(index, align_mask);

    end = index + nr;
    if (end > size)
        return end;
    i = find_next_bit(map, end, index);
    if (i < end) {
        start = i + 1;
        goto again;
    }
    return index;
}
EXPORT_SYMBOL(bitmap_find_next_zero_area);

/*
 * Bitmap printing & parsing functions: first version by Bill Irwin,
 * second version by Paul Jackson, third by Joe Korty.
 */

#define CHUNKSZ             32
#define nbits_to_hold_value(val)    fls(val)
#define BASEDEC 10      /* fancier cpuset lists input in decimal */

int bitmap_scnprintf(char *buf, unsigned int buflen,
    const unsigned long *maskp, int nmaskbits)
{
    int i, word, bit, len = 0;
    unsigned long val;
    const char *sep = "";
    int chunksz;
    u32 chunkmask;

    chunksz = nmaskbits & (CHUNKSZ - 1);
    if (chunksz == 0)
        chunksz = CHUNKSZ;

    i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ;
    for (; i >= 0; i -= CHUNKSZ) {
        chunkmask = ((1ULL << chunksz) - 1);
        word = i / BITS_PER_LONG;
        bit = i % BITS_PER_LONG;
        val = (maskp[word] >> bit) & chunkmask;
        len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep,
            (chunksz+3)/4, val);
        chunksz = CHUNKSZ;
        sep = ",";
    }
    return len;
}
EXPORT_SYMBOL(bitmap_scnprintf);

int __bitmap_parse(const char *buf, unsigned int buflen,
        int is_user, unsigned long *maskp,
        int nmaskbits)
{
    int c, old_c, totaldigits, ndigits, nchunks, nbits;
    u32 chunk;
    const char __user __force *ubuf = (const char __user __force *)buf;

    bitmap_zero(maskp, nmaskbits);

    nchunks = nbits = totaldigits = c = 0;
    do {
        chunk = ndigits = 0;

        /* Get the next chunk of the bitmap */
        while (buflen) {
            old_c = c;
            if (is_user) {
                if (__get_user(c, ubuf++))
                    return -EFAULT;
            }
            else
                c = *buf++;
            buflen--;
            if (isspace(c))
                continue;

            /*
             * If the last character was a space and the current
             * character isn't '\0', we've got embedded whitespace.
             * This is a no-no, so throw an error.
             */
            if (totaldigits && c && isspace(old_c))
                return -EINVAL;

            /* A '\0' or a ',' signal the end of the chunk */
            if (c == '\0' || c == ',')
                break;

            if (!isxdigit(c))
                return -EINVAL;

            /*
             * Make sure there are at least 4 free bits in 'chunk'.
             * If not, this hexdigit will overflow 'chunk', so
             * throw an error.
             */
            if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
                return -EOVERFLOW;

            chunk = (chunk << 4) | hex_to_bin(c);
            ndigits++; totaldigits++;
        }
        if (ndigits == 0)
            return -EINVAL;
        if (nchunks == 0 && chunk == 0)
            continue;

        __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
        *maskp |= chunk;
        nchunks++;
        nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
        if (nbits > nmaskbits)
            return -EOVERFLOW;
    } while (buflen && c == ',');

    return 0;
}
EXPORT_SYMBOL(__bitmap_parse);

int bitmap_parse_user(const char __user *ubuf,
            unsigned int ulen, unsigned long *maskp,
            int nmaskbits)
{
    if (!access_ok(VERIFY_READ, ubuf, ulen))
        return -EFAULT;
    return __bitmap_parse((const char __force *)ubuf,
                ulen, 1, maskp, nmaskbits);

}
EXPORT_SYMBOL(bitmap_parse_user);

/*
 * bscnl_emit(buf, buflen, rbot, rtop, bp)
 *
 * Helper routine for bitmap_scnlistprintf().  Write decimal number
 * or range to buf, suppressing output past buf+buflen, with optional
 * comma-prefix.  Return len of what was written to *buf, excluding the
 * trailing \0.
 */
static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
{
    if (len > 0)
        len += scnprintf(buf + len, buflen - len, ",");
    if (rbot == rtop)
        len += scnprintf(buf + len, buflen - len, "%d", rbot);
    else
        len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop);
    return len;
}

int bitmap_scnlistprintf(char *buf, unsigned int buflen,
    const unsigned long *maskp, int nmaskbits)
{
    int len = 0;
    /* current bit is 'cur', most recently seen range is [rbot, rtop] */
    int cur, rbot, rtop;

    if (buflen == 0)
        return 0;
    buf[0] = 0;

    rbot = cur = find_first_bit(maskp, nmaskbits);
    while (cur < nmaskbits) {
        rtop = cur;
        cur = find_next_bit(maskp, nmaskbits, cur+1);
        if (cur >= nmaskbits || cur > rtop + 1) {
            len = bscnl_emit(buf, buflen, rbot, rtop, len);
            rbot = cur;
        }
    }
    return len;
}
EXPORT_SYMBOL(bitmap_scnlistprintf);

static int __bitmap_parselist(const char *buf, unsigned int buflen,
        int is_user, unsigned long *maskp,
        int nmaskbits)
{
    unsigned a, b;
    int c, old_c, totaldigits;
    const char __user __force *ubuf = (const char __user __force *)buf;
    int exp_digit, in_range;

    totaldigits = c = 0;
    bitmap_zero(maskp, nmaskbits);
    do {
        exp_digit = 1;
        in_range = 0;
        a = b = 0;

        /* Get the next cpu# or a range of cpu#'s */
        while (buflen) {
            old_c = c;
            if (is_user) {
                if (__get_user(c, ubuf++))
                    return -EFAULT;
            } else
                c = *buf++;
            buflen--;
            if (isspace(c))
                continue;

            /*
             * If the last character was a space and the current
             * character isn't '\0', we've got embedded whitespace.
             * This is a no-no, so throw an error.
             */
            if (totaldigits && c && isspace(old_c))
                return -EINVAL;

            /* A '\0' or a ',' signal the end of a cpu# or range */
            if (c == '\0' || c == ',')
                break;

            if (c == '-') {
                if (exp_digit || in_range)
                    return -EINVAL;
                b = 0;
                in_range = 1;
                exp_digit = 1;
                continue;
            }

            if (!isdigit(c))
                return -EINVAL;

            b = b * 10 + (c - '0');
            if (!in_range)
                a = b;
            exp_digit = 0;
            totaldigits++;
        }
        if (!(a <= b))
            return -EINVAL;
        if (b >= nmaskbits)
            return -ERANGE;
        while (a <= b) {
            set_bit(a, maskp);
            a++;
        }
    } while (buflen && c == ',');
    return 0;
}

int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
{
    char *nl  = strchr(bp, '\n');
    int len;

    if (nl)
        len = nl - bp;
    else
        len = strlen(bp);

    return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
}
EXPORT_SYMBOL(bitmap_parselist);


int bitmap_parselist_user(const char __user *ubuf,
            unsigned int ulen, unsigned long *maskp,
            int nmaskbits)
{
    if (!access_ok(VERIFY_READ, ubuf, ulen))
        return -EFAULT;
    return __bitmap_parselist((const char __force *)ubuf,
                    ulen, 1, maskp, nmaskbits);
}
EXPORT_SYMBOL(bitmap_parselist_user);


static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits)
{
    int i, ord;

    if (pos < 0 || pos >= bits || !test_bit(pos, buf))
        return -1;

    i = find_first_bit(buf, bits);
    ord = 0;
    while (i < pos) {
        i = find_next_bit(buf, bits, i + 1);
            ord++;
    }
    BUG_ON(i != pos);

    return ord;
}

int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits)
{
    int pos = 0;

    if (ord >= 0 && ord < bits) {
        int i;

        for (i = find_first_bit(buf, bits);
             i < bits && ord > 0;
             i = find_next_bit(buf, bits, i + 1))
                ord--;
        if (i < bits && ord == 0)
            pos = i;
    }

    return pos;
}

void bitmap_remap(unsigned long *dst, const unsigned long *src,
        const unsigned long *old, const unsigned long *new,
        int bits)
{
    int oldbit, w;

    if (dst == src)     /* following doesn't handle inplace remaps */
        return;
    bitmap_zero(dst, bits);

    w = bitmap_weight(new, bits);
    for_each_set_bit(oldbit, src, bits) {
            int n = bitmap_pos_to_ord(old, oldbit, bits);

        if (n < 0 || w == 0)
            set_bit(oldbit, dst);   /* identity map */
        else
            set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
    }
}
EXPORT_SYMBOL(bitmap_remap);

int bitmap_bitremap(int oldbit, const unsigned long *old,
                const unsigned long *new, int bits)
{
    int w = bitmap_weight(new, bits);
    int n = bitmap_pos_to_ord(old, oldbit, bits);
    if (n < 0 || w == 0)
        return oldbit;
    else
        return bitmap_ord_to_pos(new, n % w, bits);
}
EXPORT_SYMBOL(bitmap_bitremap);

void bitmap_onto(unsigned long *dst, const unsigned long *orig,
            const unsigned long *relmap, int bits)
{
    int n, m;           /* same meaning as in above comment */

    if (dst == orig)    /* following doesn't handle inplace mappings */
        return;
    bitmap_zero(dst, bits);

    /*
     * The following code is a more efficient, but less
     * obvious, equivalent to the loop:
     *  for (m = 0; m < bitmap_weight(relmap, bits); m++) {
     *      n = bitmap_ord_to_pos(orig, m, bits);
     *      if (test_bit(m, orig))
     *          set_bit(n, dst);
     *  }
     */

    m = 0;
    for_each_set_bit(n, relmap, bits) {
        /* m == bitmap_pos_to_ord(relmap, n, bits) */
        if (test_bit(m, orig))
            set_bit(n, dst);
        m++;
    }
}
EXPORT_SYMBOL(bitmap_onto);

void bitmap_fold(unsigned long *dst, const unsigned long *orig,
            int sz, int bits)
{
    int oldbit;

    if (dst == orig)    /* following doesn't handle inplace mappings */
        return;
    bitmap_zero(dst, bits);

    for_each_set_bit(oldbit, orig, bits)
        set_bit(oldbit % sz, dst);
}
EXPORT_SYMBOL(bitmap_fold);

/*
 * Common code for bitmap_*_region() routines.
 *  bitmap: array of unsigned longs corresponding to the bitmap
 *  pos: the beginning of the region
 *  order: region size (log base 2 of number of bits)
 *  reg_op: operation(s) to perform on that region of bitmap
 *
 * Can set, verify and/or release a region of bits in a bitmap,
 * depending on which combination of REG_OP_* flag bits is set.
 *
 * A region of a bitmap is a sequence of bits in the bitmap, of
 * some size '1 << order' (a power of two), aligned to that same
 * '1 << order' power of two.
 *
 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
 * Returns 0 in all other cases and reg_ops.
 */

enum {
    REG_OP_ISFREE,      /* true if region is all zero bits */
    REG_OP_ALLOC,       /* set all bits in region */
    REG_OP_RELEASE,     /* clear all bits in region */
};

static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op)
{
    int nbits_reg;      /* number of bits in region */
    int index;      /* index first long of region in bitmap */
    int offset;     /* bit offset region in bitmap[index] */
    int nlongs_reg;     /* num longs spanned by region in bitmap */
    int nbitsinlong;    /* num bits of region in each spanned long */
    unsigned long mask; /* bitmask for one long of region */
    int i;          /* scans bitmap by longs */
    int ret = 0;        /* return value */

    /*
     * Either nlongs_reg == 1 (for small orders that fit in one long)
     * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
     */
    nbits_reg = 1 << order;
    index = pos / BITS_PER_LONG;
    offset = pos - (index * BITS_PER_LONG);
    nlongs_reg = BITS_TO_LONGS(nbits_reg);
    nbitsinlong = min(nbits_reg,  BITS_PER_LONG);

    /*
     * Can't do "mask = (1UL << nbitsinlong) - 1", as that
     * overflows if nbitsinlong == BITS_PER_LONG.
     */
    mask = (1UL << (nbitsinlong - 1));
    mask += mask - 1;
    mask <<= offset;

    switch (reg_op) {
    case REG_OP_ISFREE:
        for (i = 0; i < nlongs_reg; i++) {
            if (bitmap[index + i] & mask)
                goto done;
        }
        ret = 1;    /* all bits in region free (zero) */
        break;

    case REG_OP_ALLOC:
        for (i = 0; i < nlongs_reg; i++)
            bitmap[index + i] |= mask;
        break;

    case REG_OP_RELEASE:
        for (i = 0; i < nlongs_reg; i++)
            bitmap[index + i] &= ~mask;
        break;
    }
done:
    return ret;
}

int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
{
    int pos, end;       /* scans bitmap by regions of size order */

    for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) {
        if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
            continue;
        __reg_op(bitmap, pos, order, REG_OP_ALLOC);
        return pos;
    }
    return -ENOMEM;
}
EXPORT_SYMBOL(bitmap_find_free_region);

void bitmap_release_region(unsigned long *bitmap, int pos, int order)
{
    __reg_op(bitmap, pos, order, REG_OP_RELEASE);
}
EXPORT_SYMBOL(bitmap_release_region);

int bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
{
    if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
        return -EBUSY;
    __reg_op(bitmap, pos, order, REG_OP_ALLOC);
    return 0;
}
EXPORT_SYMBOL(bitmap_allocate_region);

void bitmap_copy_le(void *dst, const unsigned long *src, int nbits)
{
    unsigned long *d = dst;
    int i;

    for (i = 0; i < nbits/BITS_PER_LONG; i++) {
        if (BITS_PER_LONG == 64)
            d[i] = cpu_to_le64(src[i]);
        else
            d[i] = cpu_to_le32(src[i]);
    }
}
EXPORT_SYMBOL(bitmap_copy_le);