X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=lib%2Fbitmap.c;h=35a1f7ff414988d86c6c081d7bbf3671733a15d6;hb=4c60117811171d867d4f27f17ea07d7419d45dae;hp=23d3b1147fe93aa282a2d772493c64dde9d4dd50;hpb=fb5eeeee44edb248b4837416966f19731f497f79;p=safe%2Fjmp%2Flinux-2.6 diff --git a/lib/bitmap.c b/lib/bitmap.c index 23d3b11..35a1f7f 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -95,12 +95,12 @@ void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits) } EXPORT_SYMBOL(__bitmap_complement); -/* +/** * __bitmap_shift_right - logical right shift of the bits in a bitmap - * @dst - destination bitmap - * @src - source bitmap - * @nbits - shift by this many bits - * @bits - bitmap size, in bits + * @dst : destination bitmap + * @src : source bitmap + * @shift : shift by this many bits + * @bits : bitmap size, in bits * * Shifting right (dividing) means moving bits in the MS -> LS bit * direction. Zeros are fed into the vacated MS positions and the @@ -139,12 +139,12 @@ void __bitmap_shift_right(unsigned long *dst, EXPORT_SYMBOL(__bitmap_shift_right); -/* +/** * __bitmap_shift_left - logical left shift of the bits in a bitmap - * @dst - destination bitmap - * @src - source bitmap - * @nbits - shift by this many bits - * @bits - bitmap size, in bits + * @dst : destination bitmap + * @src : source bitmap + * @shift : shift by this many bits + * @bits : bitmap size, in bits * * Shifting left (multiplying) means moving bits in the LS -> MS * direction. Zeros are fed into the vacated LS bit positions @@ -253,33 +253,18 @@ int __bitmap_subset(const unsigned long *bitmap1, } EXPORT_SYMBOL(__bitmap_subset); -#if BITS_PER_LONG == 32 -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 += hweight32(bitmap[k]); - - if (bits % BITS_PER_LONG) - w += hweight32(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); - - return w; -} -#else 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 += hweight64(bitmap[k]); + w += hweight_long(bitmap[k]); if (bits % BITS_PER_LONG) - w += hweight64(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); + w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); return w; } -#endif EXPORT_SYMBOL(__bitmap_weight); /* @@ -331,25 +316,28 @@ int bitmap_scnprintf(char *buf, unsigned int buflen, EXPORT_SYMBOL(bitmap_scnprintf); /** - * bitmap_parse - convert an ASCII hex string into a bitmap. - * @buf: pointer to buffer in user space containing string. + * __bitmap_parse - convert an ASCII hex string into a bitmap. + * @buf: pointer to buffer containing string. * @buflen: buffer size in bytes. If string is smaller than this * then it must be terminated with a \0. + * @is_user: location of buffer, 0 indicates kernel space * @maskp: pointer to bitmap array that will contain result. * @nmaskbits: size of bitmap, in bits. * * Commas group hex digits into chunks. Each chunk defines exactly 32 * bits of the resultant bitmask. No chunk may specify a value larger - * than 32 bits (-EOVERFLOW), and if a chunk specifies a smaller value - * then leading 0-bits are prepended. -EINVAL is returned for illegal + * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value + * then leading 0-bits are prepended. %-EINVAL is returned for illegal * characters and for grouping errors such as "1,,5", ",44", "," and "". * Leading and trailing whitespace accepted, but not embedded whitespace. */ -int bitmap_parse(const char __user *ubuf, unsigned int ubuflen, - unsigned long *maskp, int nmaskbits) +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 *ubuf = buf; bitmap_zero(maskp, nmaskbits); @@ -358,11 +346,15 @@ int bitmap_parse(const char __user *ubuf, unsigned int ubuflen, chunk = ndigits = 0; /* Get the next chunk of the bitmap */ - while (ubuflen) { + while (buflen) { old_c = c; - if (get_user(c, ubuf++)) - return -EFAULT; - ubuflen--; + if (is_user) { + if (__get_user(c, ubuf++)) + return -EFAULT; + } + else + c = *buf++; + buflen--; if (isspace(c)) continue; @@ -403,11 +395,36 @@ int bitmap_parse(const char __user *ubuf, unsigned int ubuflen, nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; if (nbits > nmaskbits) return -EOVERFLOW; - } while (ubuflen && c == ','); + } while (buflen && c == ','); return 0; } -EXPORT_SYMBOL(bitmap_parse); +EXPORT_SYMBOL(__bitmap_parse); + +/** + * bitmap_parse_user() + * + * @ubuf: pointer to user buffer containing string. + * @ulen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + * + * Wrapper for __bitmap_parse(), providing it with user buffer. + * + * We cannot have this as an inline function in bitmap.h because it needs + * linux/uaccess.h to get the access_ok() declaration and this causes + * cyclic dependencies. + */ +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 *)ubuf, ulen, 1, maskp, nmaskbits); +} +EXPORT_SYMBOL(bitmap_parse_user); /* * bscnl_emit(buf, buflen, rbot, rtop, bp) @@ -452,6 +469,10 @@ int bitmap_scnlistprintf(char *buf, unsigned int buflen, /* 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; @@ -467,8 +488,8 @@ EXPORT_SYMBOL(bitmap_scnlistprintf); /** * bitmap_parselist - convert list format ASCII string to bitmap - * @buf: read nul-terminated user string from this buffer - * @mask: write resulting mask here + * @bp: read nul-terminated user string from this buffer + * @maskp: write resulting mask here * @nmaskbits: number of bits in mask to be written * * Input format is a comma-separated list of decimal numbers and @@ -476,10 +497,11 @@ EXPORT_SYMBOL(bitmap_scnlistprintf); * decimal numbers, the smallest and largest bit numbers set in * the range. * - * Returns 0 on success, -errno on invalid input strings: - * -EINVAL: second number in range smaller than first - * -EINVAL: invalid character in string - * -ERANGE: bit number specified too large for mask + * Returns 0 on success, -errno on invalid input strings. + * Error values: + * %-EINVAL: second number in range smaller than first + * %-EINVAL: invalid character in string + * %-ERANGE: bit number specified too large for mask */ int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) { @@ -511,7 +533,7 @@ int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) } EXPORT_SYMBOL(bitmap_parselist); -/* +/** * bitmap_pos_to_ord(buf, pos, bits) * @buf: pointer to a bitmap * @pos: a bit position in @buf (0 <= @pos < @bits) @@ -519,7 +541,7 @@ EXPORT_SYMBOL(bitmap_parselist); * * Map the bit at position @pos in @buf (of length @bits) to the * ordinal of which set bit it is. If it is not set or if @pos - * is not a valid bit position, map to zero (0). + * is not a valid bit position, map to -1. * * If for example, just bits 4 through 7 are set in @buf, then @pos * values 4 through 7 will get mapped to 0 through 3, respectively, @@ -531,18 +553,19 @@ EXPORT_SYMBOL(bitmap_parselist); */ static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) { - int ord = 0; + int i, ord; - if (pos >= 0 && pos < bits) { - int i; + if (pos < 0 || pos >= bits || !test_bit(pos, buf)) + return -1; - for (i = find_first_bit(buf, bits); - i < pos; - i = find_next_bit(buf, bits, i + 1)) - ord++; - if (i > pos) - ord = 0; + 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; } @@ -553,11 +576,12 @@ static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) * @bits: number of valid bit positions in @buf * * Map the ordinal offset of bit @ord in @buf to its position in @buf. - * If @ord is not the ordinal offset of a set bit in @buf, map to zero (0). + * Value of @ord should be in range 0 <= @ord < weight(buf), else + * results are undefined. * * If for example, just bits 4 through 7 are set in @buf, then @ord * values 0 through 3 will get mapped to 4 through 7, respectively, - * and all other @ord valuds will get mapped to 0. When @ord value 3 + * and all other @ord values return undefined values. When @ord value 3 * gets mapped to (returns) @pos value 7 in this example, that means * that the 3rd set bit (starting with 0th) is at position 7 in @buf. * @@ -583,8 +607,8 @@ static int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) /** * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap - * @src: subset to be remapped * @dst: remapped result + * @src: subset to be remapped * @old: defines domain of map * @new: defines range of map * @bits: number of bits in each of these bitmaps @@ -596,59 +620,52 @@ static int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) * weight of @old, map the position of the n-th set bit in @old to * the position of the m-th set bit in @new, where m == n % w. * - * If either of the @old and @new bitmaps are empty, or if@src and @dst - * point to the same location, then this routine does nothing. + * If either of the @old and @new bitmaps are empty, or if @src and + * @dst point to the same location, then this routine copies @src + * to @dst. * - * The positions of unset bits in @old are mapped to the position of - * the first set bit in @new. + * The positions of unset bits in @old are mapped to themselves + * (the identify map). * * Apply the above specified mapping to @src, placing the result in * @dst, clearing any bits previously set in @dst. * - * The resulting value of @dst will have either the same weight as - * @src, or less weight in the general case that the mapping wasn't - * injective due to the weight of @new being less than that of @old. - * The resulting value of @dst will never have greater weight than - * that of @src, except perhaps in the case that one of the above - * conditions was not met and this routine just returned. - * * For example, lets say that @old has bits 4 through 7 set, and * @new has bits 12 through 15 set. This defines the mapping of bit * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other - * bit positions to 12 (the first set bit in @new. So if say @src - * comes into this routine with bits 1, 5 and 7 set, then @dst should - * leave with bits 12, 13 and 15 set. + * bit positions unchanged. So if say @src comes into this routine + * with bits 1, 5 and 7 set, then @dst should leave with bits 1, + * 13 and 15 set. */ void bitmap_remap(unsigned long *dst, const unsigned long *src, const unsigned long *old, const unsigned long *new, int bits) { - int s; + int oldbit, w; - if (bitmap_weight(old, bits) == 0) - return; - if (bitmap_weight(new, bits) == 0) - return; if (dst == src) /* following doesn't handle inplace remaps */ return; - bitmap_zero(dst, bits); - for (s = find_first_bit(src, bits); - s < bits; - s = find_next_bit(src, bits, s + 1)) { - int x = bitmap_pos_to_ord(old, s, bits); - int y = bitmap_ord_to_pos(new, x, bits); - set_bit(y, dst); + + w = bitmap_weight(new, bits); + for (oldbit = find_first_bit(src, bits); + oldbit < bits; + oldbit = find_next_bit(src, bits, oldbit + 1)) { + 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); /** * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit - * @oldbit - bit position to be mapped - * @old: defines domain of map - * @new: defines range of map - * @bits: number of bits in each of these bitmaps + * @oldbit: bit position to be mapped + * @old: defines domain of map + * @new: defines range of map + * @bits: number of bits in each of these bitmaps * * Let @old and @new define a mapping of bit positions, such that * whatever position is held by the n-th set bit in @old is mapped @@ -657,8 +674,8 @@ EXPORT_SYMBOL(bitmap_remap); * weight of @old, map the position of the n-th set bit in @old to * the position of the m-th set bit in @new, where m == n % w. * - * The positions of unset bits in @old are mapped to the position of - * the first set bit in @new. + * The positions of unset bits in @old are mapped to themselves + * (the identify map). * * Apply the above specified mapping to bit position @oldbit, returning * the new bit position. @@ -666,95 +683,338 @@ EXPORT_SYMBOL(bitmap_remap); * For example, lets say that @old has bits 4 through 7 set, and * @new has bits 12 through 15 set. This defines the mapping of bit * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other - * bit positions to 12 (the first set bit in @new. So if say @oldbit - * is 5, then this routine returns 13. + * bit positions unchanged. So if say @oldbit is 5, then this routine + * returns 13. */ int bitmap_bitremap(int oldbit, const unsigned long *old, const unsigned long *new, int bits) { - int x = bitmap_pos_to_ord(old, oldbit, bits); - return bitmap_ord_to_pos(new, x, 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); /** - * bitmap_find_free_region - find a contiguous aligned mem region - * @bitmap: an array of unsigned longs corresponding to the bitmap - * @bits: number of bits in the bitmap - * @order: region size to find (size is actually 1< | the n-th bit of @relmap is the + * m-th set bit of @relmap }. + * + * Any set bits in @orig above bit number W, where W is the + * weight of (number of set bits in) @relmap are mapped nowhere. + * In particular, if for all bits m set in @orig, m >= W, then + * @dst will end up empty. In situations where the possibility + * of such an empty result is not desired, one way to avoid it is + * to use the bitmap_fold() operator, below, to first fold the + * @orig bitmap over itself so that all its set bits x are in the + * range 0 <= x < W. The bitmap_fold() operator does this by + * setting the bit (m % W) in @dst, for each bit (m) set in @orig. + * + * Example [1] for bitmap_onto(): + * Let's say @relmap has bits 30-39 set, and @orig has bits + * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, + * @dst will have bits 31, 33, 35, 37 and 39 set. + * + * When bit 0 is set in @orig, it means turn on the bit in + * @dst corresponding to whatever is the first bit (if any) + * that is turned on in @relmap. Since bit 0 was off in the + * above example, we leave off that bit (bit 30) in @dst. + * + * When bit 1 is set in @orig (as in the above example), it + * means turn on the bit in @dst corresponding to whatever + * is the second bit that is turned on in @relmap. The second + * bit in @relmap that was turned on in the above example was + * bit 31, so we turned on bit 31 in @dst. + * + * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, + * because they were the 4th, 6th, 8th and 10th set bits + * set in @relmap, and the 4th, 6th, 8th and 10th bits of + * @orig (i.e. bits 3, 5, 7 and 9) were also set. + * + * When bit 11 is set in @orig, it means turn on the bit in + * @dst corresponding to whatever is the twelth bit that is + * turned on in @relmap. In the above example, there were + * only ten bits turned on in @relmap (30..39), so that bit + * 11 was set in @orig had no affect on @dst. + * + * Example [2] for bitmap_fold() + bitmap_onto(): + * Let's say @relmap has these ten bits set: + * 40 41 42 43 45 48 53 61 74 95 + * (for the curious, that's 40 plus the first ten terms of the + * Fibonacci sequence.) + * + * Further lets say we use the following code, invoking + * bitmap_fold() then bitmap_onto, as suggested above to + * avoid the possitility of an empty @dst result: + * + * unsigned long *tmp; // a temporary bitmap's bits + * + * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); + * bitmap_onto(dst, tmp, relmap, bits); + * + * Then this table shows what various values of @dst would be, for + * various @orig's. I list the zero-based positions of each set bit. + * The tmp column shows the intermediate result, as computed by + * using bitmap_fold() to fold the @orig bitmap modulo ten + * (the weight of @relmap). + * + * @orig tmp @dst + * 0 0 40 + * 1 1 41 + * 9 9 95 + * 10 0 40 (*) + * 1 3 5 7 1 3 5 7 41 43 48 61 + * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 + * 0 9 18 27 0 9 8 7 40 61 74 95 + * 0 10 20 30 0 40 + * 0 11 22 33 0 1 2 3 40 41 42 43 + * 0 12 24 36 0 2 4 6 40 42 45 53 + * 78 102 211 1 2 8 41 42 74 (*) + * + * (*) For these marked lines, if we hadn't first done bitmap_fold() + * into tmp, then the @dst result would have been empty. + * + * If either of @orig or @relmap is empty (no set bits), then @dst + * will be returned empty. + * + * If (as explained above) the only set bits in @orig are in positions + * m where m >= W, (where W is the weight of @relmap) then @dst will + * once again be returned empty. + * + * All bits in @dst not set by the above rule are cleared. + */ +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 (n = find_first_bit(relmap, bits); + n < bits; + n = find_next_bit(relmap, bits, n + 1)) { + /* m == bitmap_pos_to_ord(relmap, n, bits) */ + if (test_bit(m, orig)) + set_bit(n, dst); + m++; + } +} +EXPORT_SYMBOL(bitmap_onto); + +/** + * bitmap_fold - fold larger bitmap into smaller, modulo specified size + * @dst: resulting smaller bitmap + * @orig: original larger bitmap + * @sz: specified size + * @bits: number of bits in each of these bitmaps * - * Returns either beginning of region or negative error + * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. + * Clear all other bits in @dst. See further the comment and + * Example [2] for bitmap_onto() for why and how to use this. */ -int bitmap_find_free_region(unsigned long *bitmap, int bits, int order) +void bitmap_fold(unsigned long *dst, const unsigned long *orig, + int sz, int bits) { - unsigned long mask; - int pages = 1 << order; - int i; + int oldbit; + + if (dst == orig) /* following doesn't handle inplace mappings */ + return; + bitmap_zero(dst, bits); - if(pages > BITS_PER_LONG) - return -EINVAL; + for (oldbit = find_first_bit(orig, bits); + oldbit < bits; + oldbit = find_next_bit(orig, bits, oldbit + 1)) + set_bit(oldbit % sz, dst); +} +EXPORT_SYMBOL(bitmap_fold); - /* make a mask of the order */ - mask = (1ul << (pages - 1)); +/* + * 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; - /* run up the bitmap pages bits at a time */ - for (i = 0; i < bits; i += pages) { - int index = i/BITS_PER_LONG; - int offset = i - (index * BITS_PER_LONG); - if((bitmap[index] & (mask << offset)) == 0) { - /* set region in bimap */ - bitmap[index] |= (mask << offset); - return i; + 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; +} + +/** + * bitmap_find_free_region - find a contiguous aligned mem region + * @bitmap: array of unsigned longs corresponding to the bitmap + * @bits: number of bits in the bitmap + * @order: region size (log base 2 of number of bits) to find + * + * Find a region of free (zero) bits in a @bitmap of @bits bits and + * allocate them (set them to one). Only consider regions of length + * a power (@order) of two, aligned to that power of two, which + * makes the search algorithm much faster. + * + * Return the bit offset in bitmap of the allocated region, + * or -errno on failure. + */ +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); /** - * bitmap_release_region - release allocated bitmap region - * @bitmap: a pointer to the bitmap - * @pos: the beginning of the region - * @order: the order of the bits to release (number is 1< BITS_PER_LONG. The - * algorithm would be a simple look for multiple zeros in the - * array, but there's no driver today that needs this. If you - * trip this BUG(), you get to code it... */ - BUG_ON(pages > BITS_PER_LONG); - mask += mask - 1; - if (bitmap[index] & (mask << offset)) + if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) return -EBUSY; - bitmap[index] |= (mask << offset); + __reg_op(bitmap, pos, order, REG_OP_ALLOC); return 0; } EXPORT_SYMBOL(bitmap_allocate_region); + +/** + * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. + * @dst: destination buffer + * @src: bitmap to copy + * @nbits: number of bits in the bitmap + * + * Require nbits % BITS_PER_LONG == 0. + */ +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);