Commit 07a262cc authored by Peter Xu's avatar Peter Xu Committed by Paolo Bonzini
Browse files

tools: introduce test_and_clear_bit 



We have test_and_set_bit but not test_and_clear_bit.  Add it.

Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 024d83ca

tools/include/linux/bitmap.h

+17 −0
Original line number Diff line number Diff line
@@ -96,6 +96,23 @@ static inline int test_and_set_bit(int nr, unsigned long *addr) 
	return (old & mask) != 0;

}



/**

 * test_and_clear_bit - Clear a bit and return its old value

 * @nr: Bit to clear

 * @addr: Address to count from

 */

static inline int test_and_clear_bit(int nr, unsigned long *addr)

{

	unsigned long mask = BIT_MASK(nr);

	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);

	unsigned long old;



	old = *p;

	*p = old & ~mask;



	return (old & mask) != 0;

}



/**

 * bitmap_alloc - Allocate bitmap

 * @nbits: Number of bits