Commit 14a99e13 authored by Yury Norov's avatar Yury Norov
Browse files

lib/find_bit: create find_first_zero_bit_le() 



find_first_zero_bit_le() is an alias to find_next_zero_bit_le(),
despite that 'next' is known to be slower than 'first' version.

Now that we have common FIND_FIRST_BIT() macro helper, it's trivial
to implement find_first_zero_bit_le() as a real function.

Reviewed-by: default avatarValentin Schneider <vschneid@redhat.com>
Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
parent 58414bbb

include/linux/find.h

+18 −5
Original line number Diff line number Diff line
@@ -17,6 +17,10 @@ extern unsigned long _find_first_and_bit(const unsigned long *addr1, 
extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size);

extern unsigned long _find_last_bit(const unsigned long *addr, unsigned long size);



#ifdef __BIG_ENDIAN

unsigned long _find_first_zero_bit_le(const unsigned long *addr, unsigned long size);

#endif



#ifndef find_next_bit

/**

 * find_next_bit - find the next set bit in a memory region
@@ -251,6 +255,20 @@ unsigned long find_next_zero_bit_le(const void *addr, unsigned 
}

#endif



#ifndef find_first_zero_bit_le

static inline

unsigned long find_first_zero_bit_le(const void *addr, unsigned long size)

{

	if (small_const_nbits(size)) {

		unsigned long val = swab(*(const unsigned long *)addr) | ~GENMASK(size - 1, 0);



		return val == ~0UL ? size : ffz(val);

	}



	return _find_first_zero_bit_le(addr, size);

}

#endif



#ifndef find_next_bit_le

static inline

unsigned long find_next_bit_le(const void *addr, unsigned
@@ -270,11 +288,6 @@ unsigned long find_next_bit_le(const void *addr, unsigned 
}

#endif



#ifndef find_first_zero_bit_le

#define find_first_zero_bit_le(addr, size) \

	find_next_zero_bit_le((addr), (size), 0)

#endif



#else

#error "Please fix <asm/byteorder.h>"

#endif

lib/find_bit.c

+16 −0
Original line number Diff line number Diff line
@@ -160,3 +160,19 @@ unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr, 
	return offset;

}

EXPORT_SYMBOL(find_next_clump8);



#ifdef __BIG_ENDIAN



#ifndef find_first_zero_bit_le

/*

 * Find the first cleared bit in an LE memory region.

 */

unsigned long _find_first_zero_bit_le(const unsigned long *addr, unsigned long size)

{

	return FIND_FIRST_BIT(~addr[idx], swab, size);

}

EXPORT_SYMBOL(_find_first_zero_bit_le);



#endif



#endif /* __BIG_ENDIAN */