linux-master/lib/bitmap.c

86  *   @nbits : bitmap size, in bits
93 			unsigned shift, unsigned nbits)
95 	unsigned k, lim = BITS_TO_LONGS(nbits);
97 	unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
130  *   @nbits : bitmap size, in bits
138 			unsigned int shift, unsigned int nbits)
141 	unsigned int lim = BITS_TO_LONGS(nbits);
168  * @nbits: bitmap size, in bits
172  * m such that @first <= n < nbits, and m = n + @cut.
200 		unsigned int first, unsigned int cut, unsigned int nbits)
202 	unsigned int len = BITS_TO_LONGS(nbits);
285 		      const unsigned long *mask, unsigned int nbits)
288 	unsigned int nr = BITS_TO_LONGS(nbits);
442  *	@pos: a bit position in @buf (0 <= @pos < @nbits)
443  *	@nbits: number of valid bit positions in @buf
445  * Map the bit at position @pos in @buf (of length @nbits) to the
457 static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
459 	if (pos >= nbits || !test_bit(pos, buf))
471  *	@nbits: number of bits in each of these bitmaps
499 		unsigned int nbits)
505 	bitmap_zero(dst, nbits);
507 	w = bitmap_weight(new, nbits);
508 	for_each_set_bit(oldbit, src, nbits) {
509 		int n = bitmap_pos_to_ord(old, oldbit, nbits);
514 			set_bit(find_nth_bit(new, nbits, n % w), dst);
697  *	@nbits: number of bits in each of these bitmaps
704 			unsigned int sz, unsigned int nbits)
710 	bitmap_zero(dst, nbits);
712 	for_each_set_bit(oldbit, orig, nbits)
717 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
719 	return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
724 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
726 	return bitmap_alloc(nbits, flags | __GFP_ZERO);
730 unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node)
732 	return kmalloc_array_node(BITS_TO_LONGS(nbits), sizeof(unsigned long),
737 unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node)
739 	return bitmap_alloc_node(nbits, flags | __GFP_ZERO, node);
757 				 unsigned int nbits, gfp_t flags)
762 	bitmap = bitmap_alloc(nbits, flags);
775 				  unsigned int nbits, gfp_t flags)
777 	return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO);
786  *	@nbits: number of bits in @bitmap
788 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
792 	halfwords = DIV_ROUND_UP(nbits, 32);
799 	/* Clear tail bits in last word beyond nbits. */
800 	if (nbits % BITS_PER_LONG)
801 		bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
809  *	@nbits: number of bits in @bitmap
811 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
815 	halfwords = DIV_ROUND_UP(nbits, 32);
822 	/* Clear tail bits in last element of array beyond nbits. */
823 	if (nbits % BITS_PER_LONG)
824 		buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
834  *	@nbits: number of bits in @bitmap
836 void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits)
840 	for (n = nbits; n > 0; n -= 64) {
849 	 * Clear tail bits in the last word beyond nbits.
852 	 * to the last word of the bitmap, except for nbits == 0, which
855 	if (nbits % BITS_PER_LONG)
856 		bitmap[-1] &= BITMAP_LAST_WORD_MASK(nbits);
864  *	@nbits: number of bits in @bitmap
866 void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits)
868 	const unsigned long *end = bitmap + BITS_TO_LONGS(nbits);
877 	/* Clear tail bits in the last element of array beyond nbits. */
878 	if (nbits % 64)
879 		buf[-1] &= GENMASK_ULL((nbits - 1) % 64, 0);