[PATCH 06/13] lib: extend the scope of small_const_nbits() macro
From: Yury Norov <yury.norov@gmail.com>
Date: 2021-03-16 01:55:41
Also in:
linux-m68k, linux-sh, lkml
Subsystem:
bitmap api, generic include/asm header files, the rest · Maintainers:
Yury Norov, Arnd Bergmann, Linus Torvalds
find_bit would also benefit from small_const_nbits() optimizations. Signed-off-by: Yury Norov <yury.norov@gmail.com> --- include/asm-generic/bitsperlong.h | 9 +++++++++ include/linux/bitmap.h | 3 --- 2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/include/asm-generic/bitsperlong.h b/include/asm-generic/bitsperlong.h
index 3905c1c93dc2..96032f4f908f 100644
--- a/include/asm-generic/bitsperlong.h
+++ b/include/asm-generic/bitsperlong.h@@ -23,4 +23,13 @@ #define BITS_PER_LONG_LONG 64 #endif +#define SMALL_CONST(n) (__builtin_constant_p(n) && (unsigned long)(n) < BITS_PER_LONG) + +/* + * The valid number of bits for a bitmap to be small enough, or in other words, + * fit into a single machine word is 1 to BITS_PER_LONG inclusively. 0 is not a + * valid number for size, and most probably a sing of error. + */ +#define small_const_nbits(n) SMALL_CONST((n) - 1) + #endif /* __ASM_GENERIC_BITS_PER_LONG */
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index adf7bd9f0467..bc13a890ecc1 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h@@ -224,9 +224,6 @@ extern int bitmap_print_to_pagebuf(bool list, char *buf, * so make such users (should any ever turn up) call the out-of-line * versions. */ -#define small_const_nbits(nbits) \ - (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0) - static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) { unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
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2.25.1