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![Yury Norov](/assets/img/avatar_default.png)
Similarly to cpumask_weight_and(), cpumask_weight_andnot() is a handy helper that may help to avoid creating an intermediate mask just to calculate number of bits that set in a 1st given mask, and clear in 2nd one. Signed-off-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
883 lines
27 KiB
C
883 lines
27 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* lib/bitmap.c
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* Helper functions for bitmap.h.
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*/
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#include <linux/bitmap.h>
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#include <linux/bitops.h>
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#include <linux/ctype.h>
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#include <linux/device.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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/**
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* DOC: bitmap introduction
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*
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* bitmaps provide an array of bits, implemented using an
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* array of unsigned longs. The number of valid bits in a
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* given bitmap does _not_ need to be an exact multiple of
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* BITS_PER_LONG.
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*
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* The possible unused bits in the last, partially used word
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* of a bitmap are 'don't care'. The implementation makes
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* no particular effort to keep them zero. It ensures that
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* their value will not affect the results of any operation.
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* The bitmap operations that return Boolean (bitmap_empty,
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* for example) or scalar (bitmap_weight, for example) results
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* carefully filter out these unused bits from impacting their
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* results.
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*
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* The byte ordering of bitmaps is more natural on little
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* endian architectures. See the big-endian headers
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* include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
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* for the best explanations of this ordering.
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*/
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bool __bitmap_equal(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k, lim = bits/BITS_PER_LONG;
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for (k = 0; k < lim; ++k)
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if (bitmap1[k] != bitmap2[k])
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return false;
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if (bits % BITS_PER_LONG)
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if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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return false;
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return true;
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}
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EXPORT_SYMBOL(__bitmap_equal);
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bool __bitmap_or_equal(const unsigned long *bitmap1,
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const unsigned long *bitmap2,
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const unsigned long *bitmap3,
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unsigned int bits)
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{
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unsigned int k, lim = bits / BITS_PER_LONG;
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unsigned long tmp;
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for (k = 0; k < lim; ++k) {
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if ((bitmap1[k] | bitmap2[k]) != bitmap3[k])
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return false;
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}
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if (!(bits % BITS_PER_LONG))
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return true;
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tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k];
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return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0;
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}
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void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
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{
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unsigned int k, lim = BITS_TO_LONGS(bits);
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for (k = 0; k < lim; ++k)
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dst[k] = ~src[k];
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}
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EXPORT_SYMBOL(__bitmap_complement);
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/**
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* __bitmap_shift_right - logical right shift of the bits in a bitmap
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* @dst : destination bitmap
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* @src : source bitmap
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* @shift : shift by this many bits
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* @nbits : bitmap size, in bits
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*
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* Shifting right (dividing) means moving bits in the MS -> LS bit
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* direction. Zeros are fed into the vacated MS positions and the
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* LS bits shifted off the bottom are lost.
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*/
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void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
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unsigned shift, unsigned nbits)
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{
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unsigned k, lim = BITS_TO_LONGS(nbits);
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unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
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for (k = 0; off + k < lim; ++k) {
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unsigned long upper, lower;
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/*
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* If shift is not word aligned, take lower rem bits of
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* word above and make them the top rem bits of result.
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*/
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if (!rem || off + k + 1 >= lim)
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upper = 0;
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else {
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upper = src[off + k + 1];
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if (off + k + 1 == lim - 1)
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upper &= mask;
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upper <<= (BITS_PER_LONG - rem);
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}
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lower = src[off + k];
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if (off + k == lim - 1)
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lower &= mask;
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lower >>= rem;
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dst[k] = lower | upper;
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}
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if (off)
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memset(&dst[lim - off], 0, off*sizeof(unsigned long));
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}
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EXPORT_SYMBOL(__bitmap_shift_right);
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/**
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* __bitmap_shift_left - logical left shift of the bits in a bitmap
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* @dst : destination bitmap
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* @src : source bitmap
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* @shift : shift by this many bits
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* @nbits : bitmap size, in bits
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*
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* Shifting left (multiplying) means moving bits in the LS -> MS
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* direction. Zeros are fed into the vacated LS bit positions
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* and those MS bits shifted off the top are lost.
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*/
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void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
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unsigned int shift, unsigned int nbits)
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{
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int k;
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unsigned int lim = BITS_TO_LONGS(nbits);
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unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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for (k = lim - off - 1; k >= 0; --k) {
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unsigned long upper, lower;
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/*
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* If shift is not word aligned, take upper rem bits of
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* word below and make them the bottom rem bits of result.
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*/
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if (rem && k > 0)
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lower = src[k - 1] >> (BITS_PER_LONG - rem);
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else
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lower = 0;
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upper = src[k] << rem;
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dst[k + off] = lower | upper;
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}
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if (off)
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memset(dst, 0, off*sizeof(unsigned long));
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}
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EXPORT_SYMBOL(__bitmap_shift_left);
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/**
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* bitmap_cut() - remove bit region from bitmap and right shift remaining bits
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* @dst: destination bitmap, might overlap with src
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* @src: source bitmap
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* @first: start bit of region to be removed
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* @cut: number of bits to remove
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* @nbits: bitmap size, in bits
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*
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* Set the n-th bit of @dst iff the n-th bit of @src is set and
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* n is less than @first, or the m-th bit of @src is set for any
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* m such that @first <= n < nbits, and m = n + @cut.
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*
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* In pictures, example for a big-endian 32-bit architecture:
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*
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* The @src bitmap is::
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*
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* 31 63
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* | |
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* 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101
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* | | | |
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* 16 14 0 32
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*
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* if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is::
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*
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* 31 63
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* | |
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* 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010
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* | | |
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* 14 (bit 17 0 32
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* from @src)
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*
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* Note that @dst and @src might overlap partially or entirely.
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*
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* This is implemented in the obvious way, with a shift and carry
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* step for each moved bit. Optimisation is left as an exercise
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* for the compiler.
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*/
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void bitmap_cut(unsigned long *dst, const unsigned long *src,
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unsigned int first, unsigned int cut, unsigned int nbits)
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{
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unsigned int len = BITS_TO_LONGS(nbits);
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unsigned long keep = 0, carry;
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int i;
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if (first % BITS_PER_LONG) {
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keep = src[first / BITS_PER_LONG] &
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(~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG));
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}
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memmove(dst, src, len * sizeof(*dst));
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while (cut--) {
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for (i = first / BITS_PER_LONG; i < len; i++) {
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if (i < len - 1)
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carry = dst[i + 1] & 1UL;
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else
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carry = 0;
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dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1));
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}
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}
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dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG);
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dst[first / BITS_PER_LONG] |= keep;
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}
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EXPORT_SYMBOL(bitmap_cut);
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bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int lim = bits/BITS_PER_LONG;
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unsigned long result = 0;
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for (k = 0; k < lim; k++)
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result |= (dst[k] = bitmap1[k] & bitmap2[k]);
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if (bits % BITS_PER_LONG)
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result |= (dst[k] = bitmap1[k] & bitmap2[k] &
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BITMAP_LAST_WORD_MASK(bits));
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return result != 0;
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}
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EXPORT_SYMBOL(__bitmap_and);
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void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int nr = BITS_TO_LONGS(bits);
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for (k = 0; k < nr; k++)
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dst[k] = bitmap1[k] | bitmap2[k];
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}
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EXPORT_SYMBOL(__bitmap_or);
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void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int nr = BITS_TO_LONGS(bits);
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for (k = 0; k < nr; k++)
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dst[k] = bitmap1[k] ^ bitmap2[k];
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}
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EXPORT_SYMBOL(__bitmap_xor);
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bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int lim = bits/BITS_PER_LONG;
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unsigned long result = 0;
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for (k = 0; k < lim; k++)
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result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
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if (bits % BITS_PER_LONG)
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result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
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BITMAP_LAST_WORD_MASK(bits));
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return result != 0;
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}
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EXPORT_SYMBOL(__bitmap_andnot);
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void __bitmap_replace(unsigned long *dst,
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const unsigned long *old, const unsigned long *new,
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const unsigned long *mask, unsigned int nbits)
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{
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unsigned int k;
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unsigned int nr = BITS_TO_LONGS(nbits);
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for (k = 0; k < nr; k++)
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dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
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}
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EXPORT_SYMBOL(__bitmap_replace);
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bool __bitmap_intersects(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k, lim = bits/BITS_PER_LONG;
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for (k = 0; k < lim; ++k)
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if (bitmap1[k] & bitmap2[k])
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return true;
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if (bits % BITS_PER_LONG)
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if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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return true;
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return false;
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}
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EXPORT_SYMBOL(__bitmap_intersects);
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bool __bitmap_subset(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k, lim = bits/BITS_PER_LONG;
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for (k = 0; k < lim; ++k)
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if (bitmap1[k] & ~bitmap2[k])
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return false;
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if (bits % BITS_PER_LONG)
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if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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return false;
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return true;
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}
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EXPORT_SYMBOL(__bitmap_subset);
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#define BITMAP_WEIGHT(FETCH, bits) \
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({ \
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unsigned int __bits = (bits), idx, w = 0; \
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\
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for (idx = 0; idx < __bits / BITS_PER_LONG; idx++) \
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w += hweight_long(FETCH); \
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\
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if (__bits % BITS_PER_LONG) \
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w += hweight_long((FETCH) & BITMAP_LAST_WORD_MASK(__bits)); \
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\
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w; \
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})
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unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
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{
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return BITMAP_WEIGHT(bitmap[idx], bits);
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}
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EXPORT_SYMBOL(__bitmap_weight);
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unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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return BITMAP_WEIGHT(bitmap1[idx] & bitmap2[idx], bits);
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}
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EXPORT_SYMBOL(__bitmap_weight_and);
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unsigned int __bitmap_weight_andnot(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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return BITMAP_WEIGHT(bitmap1[idx] & ~bitmap2[idx], bits);
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}
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EXPORT_SYMBOL(__bitmap_weight_andnot);
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void __bitmap_set(unsigned long *map, unsigned int start, int len)
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{
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unsigned long *p = map + BIT_WORD(start);
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const unsigned int size = start + len;
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int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
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unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
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while (len - bits_to_set >= 0) {
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*p |= mask_to_set;
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len -= bits_to_set;
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bits_to_set = BITS_PER_LONG;
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mask_to_set = ~0UL;
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p++;
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}
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if (len) {
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mask_to_set &= BITMAP_LAST_WORD_MASK(size);
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*p |= mask_to_set;
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}
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}
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EXPORT_SYMBOL(__bitmap_set);
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void __bitmap_clear(unsigned long *map, unsigned int start, int len)
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{
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unsigned long *p = map + BIT_WORD(start);
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const unsigned int size = start + len;
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int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
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unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
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while (len - bits_to_clear >= 0) {
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*p &= ~mask_to_clear;
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len -= bits_to_clear;
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bits_to_clear = BITS_PER_LONG;
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mask_to_clear = ~0UL;
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p++;
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}
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if (len) {
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mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
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*p &= ~mask_to_clear;
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}
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}
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EXPORT_SYMBOL(__bitmap_clear);
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/**
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* bitmap_find_next_zero_area_off - find a contiguous aligned zero area
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* @map: The address to base the search on
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* @size: The bitmap size in bits
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* @start: The bitnumber to start searching at
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* @nr: The number of zeroed bits we're looking for
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* @align_mask: Alignment mask for zero area
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* @align_offset: Alignment offset for zero area.
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*
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* The @align_mask should be one less than a power of 2; the effect is that
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* the bit offset of all zero areas this function finds plus @align_offset
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* is multiple of that power of 2.
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*/
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unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
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unsigned long size,
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unsigned long start,
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unsigned int nr,
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unsigned long align_mask,
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unsigned long align_offset)
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{
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unsigned long index, end, i;
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again:
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index = find_next_zero_bit(map, size, start);
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/* Align allocation */
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index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
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end = index + nr;
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if (end > size)
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return end;
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i = find_next_bit(map, end, index);
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if (i < end) {
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start = i + 1;
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goto again;
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}
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return index;
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}
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EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
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/**
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* bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
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* @buf: pointer to a bitmap
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* @pos: a bit position in @buf (0 <= @pos < @nbits)
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* @nbits: number of valid bit positions in @buf
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*
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* Map the bit at position @pos in @buf (of length @nbits) to the
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* ordinal of which set bit it is. If it is not set or if @pos
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* is not a valid bit position, map to -1.
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*
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* If for example, just bits 4 through 7 are set in @buf, then @pos
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* values 4 through 7 will get mapped to 0 through 3, respectively,
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* and other @pos values will get mapped to -1. When @pos value 7
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* gets mapped to (returns) @ord value 3 in this example, that means
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* that bit 7 is the 3rd (starting with 0th) set bit in @buf.
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*
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* The bit positions 0 through @bits are valid positions in @buf.
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*/
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static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
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{
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if (pos >= nbits || !test_bit(pos, buf))
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return -1;
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return bitmap_weight(buf, pos);
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}
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/**
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* bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
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* @dst: remapped result
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* @src: subset to be remapped
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* @old: defines domain of map
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* @new: defines range of map
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* @nbits: number of bits in each of these bitmaps
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*
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* Let @old and @new define a mapping of bit positions, such that
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* whatever position is held by the n-th set bit in @old is mapped
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* to the n-th set bit in @new. In the more general case, allowing
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* for the possibility that the weight 'w' of @new is less than the
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* weight of @old, map the position of the n-th set bit in @old to
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* the position of the m-th set bit in @new, where m == n % w.
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*
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* If either of the @old and @new bitmaps are empty, or if @src and
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* @dst point to the same location, then this routine copies @src
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* to @dst.
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*
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* The positions of unset bits in @old are mapped to themselves
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* (the identity map).
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*
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* Apply the above specified mapping to @src, placing the result in
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* @dst, clearing any bits previously set in @dst.
|
|
*
|
|
* 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 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,
|
|
unsigned int nbits)
|
|
{
|
|
unsigned int oldbit, w;
|
|
|
|
if (dst == src) /* following doesn't handle inplace remaps */
|
|
return;
|
|
bitmap_zero(dst, nbits);
|
|
|
|
w = bitmap_weight(new, nbits);
|
|
for_each_set_bit(oldbit, src, nbits) {
|
|
int n = bitmap_pos_to_ord(old, oldbit, nbits);
|
|
|
|
if (n < 0 || w == 0)
|
|
set_bit(oldbit, dst); /* identity map */
|
|
else
|
|
set_bit(find_nth_bit(new, nbits, n % w), 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
|
|
*
|
|
* 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
|
|
* to the n-th set bit in @new. In the more general case, allowing
|
|
* for the possibility that the weight 'w' of @new is less than the
|
|
* 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 themselves
|
|
* (the identity map).
|
|
*
|
|
* Apply the above specified mapping to bit position @oldbit, returning
|
|
* the new bit position.
|
|
*
|
|
* 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 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 w = bitmap_weight(new, bits);
|
|
int n = bitmap_pos_to_ord(old, oldbit, bits);
|
|
if (n < 0 || w == 0)
|
|
return oldbit;
|
|
else
|
|
return find_nth_bit(new, bits, n % w);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_bitremap);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/**
|
|
* bitmap_onto - translate one bitmap relative to another
|
|
* @dst: resulting translated bitmap
|
|
* @orig: original untranslated bitmap
|
|
* @relmap: bitmap relative to which translated
|
|
* @bits: number of bits in each of these bitmaps
|
|
*
|
|
* Set the n-th bit of @dst iff there exists some m such that the
|
|
* n-th bit of @relmap is set, the m-th bit of @orig is set, and
|
|
* the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
|
|
* (If you understood the previous sentence the first time your
|
|
* read it, you're overqualified for your current job.)
|
|
*
|
|
* In other words, @orig is mapped onto (surjectively) @dst,
|
|
* using the map { <n, m> | 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 twelfth 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 possibility 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 [#f1]_
|
|
* 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 [#f1]_
|
|
* =============== ============== =================
|
|
*
|
|
* .. [#f1]
|
|
*
|
|
* 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, unsigned int bits)
|
|
{
|
|
unsigned 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 = find_nth_bit(orig, bits, m);
|
|
* 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++;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* bitmap_fold - fold larger bitmap into smaller, modulo specified size
|
|
* @dst: resulting smaller bitmap
|
|
* @orig: original larger bitmap
|
|
* @sz: specified size
|
|
* @nbits: number of bits in each of these bitmaps
|
|
*
|
|
* 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.
|
|
*/
|
|
void bitmap_fold(unsigned long *dst, const unsigned long *orig,
|
|
unsigned int sz, unsigned int nbits)
|
|
{
|
|
unsigned int oldbit;
|
|
|
|
if (dst == orig) /* following doesn't handle inplace mappings */
|
|
return;
|
|
bitmap_zero(dst, nbits);
|
|
|
|
for_each_set_bit(oldbit, orig, nbits)
|
|
set_bit(oldbit % sz, dst);
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
|
|
{
|
|
return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
|
|
flags);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_alloc);
|
|
|
|
unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
|
|
{
|
|
return bitmap_alloc(nbits, flags | __GFP_ZERO);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_zalloc);
|
|
|
|
unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node)
|
|
{
|
|
return kmalloc_array_node(BITS_TO_LONGS(nbits), sizeof(unsigned long),
|
|
flags, node);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_alloc_node);
|
|
|
|
unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node)
|
|
{
|
|
return bitmap_alloc_node(nbits, flags | __GFP_ZERO, node);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_zalloc_node);
|
|
|
|
void bitmap_free(const unsigned long *bitmap)
|
|
{
|
|
kfree(bitmap);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_free);
|
|
|
|
static void devm_bitmap_free(void *data)
|
|
{
|
|
unsigned long *bitmap = data;
|
|
|
|
bitmap_free(bitmap);
|
|
}
|
|
|
|
unsigned long *devm_bitmap_alloc(struct device *dev,
|
|
unsigned int nbits, gfp_t flags)
|
|
{
|
|
unsigned long *bitmap;
|
|
int ret;
|
|
|
|
bitmap = bitmap_alloc(nbits, flags);
|
|
if (!bitmap)
|
|
return NULL;
|
|
|
|
ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap);
|
|
if (ret)
|
|
return NULL;
|
|
|
|
return bitmap;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_bitmap_alloc);
|
|
|
|
unsigned long *devm_bitmap_zalloc(struct device *dev,
|
|
unsigned int nbits, gfp_t flags)
|
|
{
|
|
return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO);
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_bitmap_zalloc);
|
|
|
|
#if BITS_PER_LONG == 64
|
|
/**
|
|
* bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
|
|
* @bitmap: array of unsigned longs, the destination bitmap
|
|
* @buf: array of u32 (in host byte order), the source bitmap
|
|
* @nbits: number of bits in @bitmap
|
|
*/
|
|
void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
|
|
{
|
|
unsigned int i, halfwords;
|
|
|
|
halfwords = DIV_ROUND_UP(nbits, 32);
|
|
for (i = 0; i < halfwords; i++) {
|
|
bitmap[i/2] = (unsigned long) buf[i];
|
|
if (++i < halfwords)
|
|
bitmap[i/2] |= ((unsigned long) buf[i]) << 32;
|
|
}
|
|
|
|
/* Clear tail bits in last word beyond nbits. */
|
|
if (nbits % BITS_PER_LONG)
|
|
bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_from_arr32);
|
|
|
|
/**
|
|
* bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits
|
|
* @buf: array of u32 (in host byte order), the dest bitmap
|
|
* @bitmap: array of unsigned longs, the source bitmap
|
|
* @nbits: number of bits in @bitmap
|
|
*/
|
|
void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
|
|
{
|
|
unsigned int i, halfwords;
|
|
|
|
halfwords = DIV_ROUND_UP(nbits, 32);
|
|
for (i = 0; i < halfwords; i++) {
|
|
buf[i] = (u32) (bitmap[i/2] & UINT_MAX);
|
|
if (++i < halfwords)
|
|
buf[i] = (u32) (bitmap[i/2] >> 32);
|
|
}
|
|
|
|
/* Clear tail bits in last element of array beyond nbits. */
|
|
if (nbits % BITS_PER_LONG)
|
|
buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
|
|
}
|
|
EXPORT_SYMBOL(bitmap_to_arr32);
|
|
#endif
|
|
|
|
#if BITS_PER_LONG == 32
|
|
/**
|
|
* bitmap_from_arr64 - copy the contents of u64 array of bits to bitmap
|
|
* @bitmap: array of unsigned longs, the destination bitmap
|
|
* @buf: array of u64 (in host byte order), the source bitmap
|
|
* @nbits: number of bits in @bitmap
|
|
*/
|
|
void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits)
|
|
{
|
|
int n;
|
|
|
|
for (n = nbits; n > 0; n -= 64) {
|
|
u64 val = *buf++;
|
|
|
|
*bitmap++ = val;
|
|
if (n > 32)
|
|
*bitmap++ = val >> 32;
|
|
}
|
|
|
|
/*
|
|
* Clear tail bits in the last word beyond nbits.
|
|
*
|
|
* Negative index is OK because here we point to the word next
|
|
* to the last word of the bitmap, except for nbits == 0, which
|
|
* is tested implicitly.
|
|
*/
|
|
if (nbits % BITS_PER_LONG)
|
|
bitmap[-1] &= BITMAP_LAST_WORD_MASK(nbits);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_from_arr64);
|
|
|
|
/**
|
|
* bitmap_to_arr64 - copy the contents of bitmap to a u64 array of bits
|
|
* @buf: array of u64 (in host byte order), the dest bitmap
|
|
* @bitmap: array of unsigned longs, the source bitmap
|
|
* @nbits: number of bits in @bitmap
|
|
*/
|
|
void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits)
|
|
{
|
|
const unsigned long *end = bitmap + BITS_TO_LONGS(nbits);
|
|
|
|
while (bitmap < end) {
|
|
*buf = *bitmap++;
|
|
if (bitmap < end)
|
|
*buf |= (u64)(*bitmap++) << 32;
|
|
buf++;
|
|
}
|
|
|
|
/* Clear tail bits in the last element of array beyond nbits. */
|
|
if (nbits % 64)
|
|
buf[-1] &= GENMASK_ULL((nbits - 1) % 64, 0);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_to_arr64);
|
|
#endif
|