[PATCH net-next v5 13/21] bitmap: make bitmap_{get,set}_value8() use bitmap_{read,write}()

Alexander Lobakin
2024-02-01T12:24:39Z

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: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
include/linux/bitmap.h | 38 +++++---------------------------------
1 file changed, 5 insertions(+), 33 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 9a6a27a7f675..f80e116b8f60 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -609,39 +609,6 @@ 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
@@ -715,6 +682,11 @@ 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 */
--
2.43.0