[linux-block.git] / tools / testing / radix-tree / bitmap.c

/* lib/bitmap.c pulls in at least two other files. */

#include <linux/bitmap.h>

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

	while (len - bits_to_clear >= 0) {
		*p &= ~mask_to_clear;
		len -= bits_to_clear;
		bits_to_clear = BITS_PER_LONG;
		mask_to_clear = ~0UL;
		p++;
	}
	if (len) {
		mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
		*p &= ~mask_to_clear;
	}
}
Commit	Line	Data
58d6ea30 MW	1	/* lib/bitmap.c pulls in at least two other files. */
	2
	3	#include <linux/bitmap.h>
	4
	5	void bitmap_clear(unsigned long *map, unsigned int start, int len)
	6	{
	7	unsigned long *p = map + BIT_WORD(start);
	8	const unsigned int size = start + len;
	9	int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
	10	unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
	11
	12	while (len - bits_to_clear >= 0) {
	13	*p &= ~mask_to_clear;
	14	len -= bits_to_clear;
	15	bits_to_clear = BITS_PER_LONG;
	16	mask_to_clear = ~0UL;
	17	p++;
	18	}
	19	if (len) {
	20	mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
	21	*p &= ~mask_to_clear;
	22	}
	23	}