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Subject[PATCH v4 2/3] lib: move find_last_bit to lib/find_next_bit.c
Date
Currently all 'find_*_bit' family is located in lib/find_next_bit.c,
except 'find_last_bit', which is in lib/find_last_bit.c. It seems,
there's no major benefit to have it separated.
---
lib/Makefile | 2 +-
lib/find_last_bit.c | 42 ------------------------------------------
lib/find_next_bit.c | 27 ++++++++++++++++++++++++++-
3 files changed, 27 insertions(+), 44 deletions(-)
delete mode 100644 lib/find_last_bit.c

diff --git a/lib/Makefile b/lib/Makefile
index 87eb3bf..9dafcd5 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -25,7 +25,7 @@ obj-y += lockref.o
obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \
gcd.o lcm.o list_sort.o uuid.o flex_array.o clz_ctz.o \
- bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o \
+ bsearch.o find_next_bit.o llist.o memweight.o kfifo.o \
percpu-refcount.o percpu_ida.o rhashtable.o reciprocal_div.o
obj-y += string_helpers.o
obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
diff --git a/lib/find_last_bit.c b/lib/find_last_bit.c
deleted file mode 100644
index edbb281..0000000
--- a/lib/find_last_bit.c
+++ /dev/null
@@ -1,42 +0,0 @@
-/* find_last_bit.c: fallback find next bit implementation
- *
- * Copyright (C) 2008 IBM Corporation
- * Written by Rusty Russell <rusty@rustcorp.com.au>
- * (Inspired by David Howell's find_next_bit implementation)
- *
- * Rewritten by Yury Norov <yury.norov@gmail.com> to decrease
- * size and improve performance, 2015.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/bitops.h>
-#include <linux/export.h>
-#include <linux/kernel.h>
-
-#define LOW_BITS_MASK(nr) (~0UL >> -(nr))
-
-#ifndef find_last_bit
-
-unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
-{
- if (size) {
- unsigned long val = LOW_BITS_MASK(size % BITS_PER_LONG);
- unsigned long idx = (size-1) / BITS_PER_LONG;
-
- do {
- val &= addr[idx];
- if (val)
- return idx * BITS_PER_LONG + __fls(val);
-
- val = ~0ul;
- } while (idx--);
- }
- return size;
-}
-EXPORT_SYMBOL(find_last_bit);
-
-#endif
diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c
index 1f5f108..627d0ec 100644
--- a/lib/find_next_bit.c
+++ b/lib/find_next_bit.c
@@ -1,8 +1,12 @@
-/* find_next_bit.c: fallback find next bit implementation
+/* bit search implementation
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
+ * Copyright (C) 2008 IBM Corporation
+ * 'find_last_bit' is written by Rusty Russell <rusty@rustcorp.com.au>
+ * (Inspired by David Howell's find_next_bit implementation)
+ *
* Rewritten by Yury Norov <yury.norov@gmail.com> to decrease
* size and improve performance, 2015.
*
@@ -17,6 +21,7 @@
#include <linux/kernel.h>

#define HIGH_BITS_MASK(nr) (~0UL << (nr))
+#define LOW_BITS_MASK(nr) (~0UL >> -(nr))

#if !defined(find_next_bit) || !defined(find_next_zero_bit)

@@ -108,6 +113,26 @@ unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
EXPORT_SYMBOL(find_first_zero_bit);
#endif

+#ifndef find_last_bit
+unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
+{
+ if (size) {
+ unsigned long val = LOW_BITS_MASK(size % BITS_PER_LONG);
+ unsigned long idx = (size-1) / BITS_PER_LONG;
+
+ do {
+ val &= addr[idx];
+ if (val)
+ return idx * BITS_PER_LONG + __fls(val);
+
+ val = ~0ul;
+ } while (idx--);
+ }
+ return size;
+}
+EXPORT_SYMBOL(find_last_bit);
+#endif
+
#ifdef __BIG_ENDIAN

/* include/linux/byteorder does not support "unsigned long" type */
--
2.1.0


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