Commit b4475970 authored by Alexander Lobakin's avatar Alexander Lobakin Committed by David S. Miller
Browse files

bitmap: make bitmap_{get,set}_value8() use bitmap_{read,write}() 



Now that we have generic bitmap_read() and bitmap_write(), which are
inline and try to take care of non-bound-crossing and aligned cases
to keep them optimized, collapse bitmap_{get,set}_value8() into
simple wrappers around the former ones.
bloat-o-meter shows no difference in vmlinux and -2 bytes for
gpio-pca953x.ko, which says the optimization didn't suffer due to
that change. The converted helpers have the value width embedded
and always compile-time constant and that helps a lot.

Suggested-by: default avatarYury Norov <yury.norov@gmail.com>
Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
Signed-off-by: default avatarAlexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a37fbe66

include/linux/bitmap.h

+5 −33
Original line number Diff line number Diff line
@@ -727,39 +727,6 @@ static inline void bitmap_from_u64(unsigned long *dst, u64 mask) 
	bitmap_from_arr64(dst, &mask, 64);

}



/**

 * bitmap_get_value8 - get an 8-bit value within a memory region

 * @map: address to the bitmap memory region

 * @start: bit offset of the 8-bit value; must be a multiple of 8

 *

 * Returns the 8-bit value located at the @start bit offset within the @src

 * memory region.

 */

static inline unsigned long bitmap_get_value8(const unsigned long *map,

					      unsigned long start)

{

	const size_t index = BIT_WORD(start);

	const unsigned long offset = start % BITS_PER_LONG;



	return (map[index] >> offset) & 0xFF;

}



/**

 * bitmap_set_value8 - set an 8-bit value within a memory region

 * @map: address to the bitmap memory region

 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap

 * @start: bit offset of the 8-bit value; must be a multiple of 8

 */

static inline void bitmap_set_value8(unsigned long *map, unsigned long value,

				     unsigned long start)

{

	const size_t index = BIT_WORD(start);

	const unsigned long offset = start % BITS_PER_LONG;



	map[index] &= ~(0xFFUL << offset);

	map[index] |= value << offset;

}



/**

 * bitmap_read - read a value of n-bits from the memory region

 * @map: address to the bitmap memory region
@@ -833,6 +800,11 @@ static inline void bitmap_write(unsigned long *map, unsigned long value, 
	map[index + 1] |= (value >> space);

}



#define bitmap_get_value8(map, start)			\

	bitmap_read(map, start, BITS_PER_BYTE)

#define bitmap_set_value8(map, value, start)		\

	bitmap_write(map, value, start, BITS_PER_BYTE)



#endif /* __ASSEMBLY__ */



#endif /* __LINUX_BITMAP_H */