On Tue, Apr 06, 2021 at 09:03:27AM -0700, Guenter Roeck wrote:
On Mon, Mar 15, 2021 at 06:54:22PM -0700, Yury Norov wrote:Similarly to bitmap functions, users would benefit if we'll handle a case of small-size bitmaps that fit into a single word. While here, move the find_last_bit() declaration to bitops/find.h where other find_*_bit() functions sit. Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx> --- include/asm-generic/bitops/find.h | 50 ++++++++++++++++++++++++++++--- include/linux/bitops.h | 12 -------- lib/find_bit.c | 12 ++++---- 3 files changed, 52 insertions(+), 22 deletions(-) diff --git a/include/asm-generic/bitops/find.h b/include/asm-generic/bitops/find.h index 4148c74a1e4d..8d818b304869 100644 --- a/include/asm-generic/bitops/find.h +++ b/include/asm-generic/bitops/find.h @@ -5,6 +5,9 @@ extern unsigned long _find_next_bit(const unsigned long *addr1, const unsigned long *addr2, unsigned long nbits, unsigned long start, unsigned long invert, unsigned long le); +extern unsigned long _find_first_bit(const unsigned long *addr, unsigned long size); +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); #ifndef find_next_bit /** @@ -102,8 +105,17 @@ unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, * Returns the bit number of the first set bit. * If no bits are set, returns @size. */ -extern unsigned long find_first_bit(const unsigned long *addr, - unsigned long size); +static inline +unsigned long find_first_bit(const unsigned long *addr, unsigned long size) +{ + if (small_const_nbits(size)) { + unsigned long val = *addr & BITS_FIRST(size - 1); + + return val ? __ffs(val) : size;This patch results in: include/asm-generic/bitops/find.h: In function 'find_last_bit': include/asm-generic/bitops/find.h:164:16: error: implicit declaration of function '__fls'; did you mean '__ffs'? and: ./include/asm-generic/bitops/__fls.h: At top level: ./include/asm-generic/bitops/__fls.h:13:38: error: conflicting types for '__fls' when building scripts/mod/devicetable-offsets.o. Seen with h8300 builds. Guenter
The patch is here: https://lkml.org/lkml/2021/4/1/1184 Yury
