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Diffstat (limited to 'lib/find_next_bit.c')
| -rw-r--r-- | lib/find_next_bit.c | 193 |
1 files changed, 0 insertions, 193 deletions
diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c deleted file mode 100644 index 18072ea9c20e..000000000000 --- a/lib/find_next_bit.c +++ /dev/null @@ -1,193 +0,0 @@ -/* 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. - * - * 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/bitmap.h> -#include <linux/export.h> -#include <linux/kernel.h> - -#if !defined(find_next_bit) || !defined(find_next_zero_bit) - -/* - * This is a common helper function for find_next_bit and - * find_next_zero_bit. The difference is the "invert" argument, which - * is XORed with each fetched word before searching it for one bits. - */ -static unsigned long _find_next_bit(const unsigned long *addr, - unsigned long nbits, unsigned long start, unsigned long invert) -{ - unsigned long tmp; - - if (!nbits || start >= nbits) - return nbits; - - tmp = addr[start / BITS_PER_LONG] ^ invert; - - /* Handle 1st word. */ - tmp &= BITMAP_FIRST_WORD_MASK(start); - start = round_down(start, BITS_PER_LONG); - - while (!tmp) { - start += BITS_PER_LONG; - if (start >= nbits) - return nbits; - - tmp = addr[start / BITS_PER_LONG] ^ invert; - } - - return min(start + __ffs(tmp), nbits); -} -#endif - -#ifndef find_next_bit -/* - * Find the next set bit in a memory region. - */ -unsigned long find_next_bit(const unsigned long *addr, unsigned long size, - unsigned long offset) -{ - return _find_next_bit(addr, size, offset, 0UL); -} -EXPORT_SYMBOL(find_next_bit); -#endif - -#ifndef find_next_zero_bit -unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, - unsigned long offset) -{ - return _find_next_bit(addr, size, offset, ~0UL); -} -EXPORT_SYMBOL(find_next_zero_bit); -#endif - -#ifndef find_first_bit -/* - * Find the first set bit in a memory region. - */ -unsigned long find_first_bit(const unsigned long *addr, unsigned long size) -{ - unsigned long idx; - - for (idx = 0; idx * BITS_PER_LONG < size; idx++) { - if (addr[idx]) - return min(idx * BITS_PER_LONG + __ffs(addr[idx]), size); - } - - return size; -} -EXPORT_SYMBOL(find_first_bit); -#endif - -#ifndef find_first_zero_bit -/* - * Find the first cleared bit in a memory region. - */ -unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) -{ - unsigned long idx; - - for (idx = 0; idx * BITS_PER_LONG < size; idx++) { - if (addr[idx] != ~0UL) - return min(idx * BITS_PER_LONG + ffz(addr[idx]), size); - } - - return 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 = BITMAP_LAST_WORD_MASK(size); - 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 */ -static inline unsigned long ext2_swab(const unsigned long y) -{ -#if BITS_PER_LONG == 64 - return (unsigned long) __swab64((u64) y); -#elif BITS_PER_LONG == 32 - return (unsigned long) __swab32((u32) y); -#else -#error BITS_PER_LONG not defined -#endif -} - -#if !defined(find_next_bit_le) || !defined(find_next_zero_bit_le) -static unsigned long _find_next_bit_le(const unsigned long *addr, - unsigned long nbits, unsigned long start, unsigned long invert) -{ - unsigned long tmp; - - if (!nbits || start >= nbits) - return nbits; - - tmp = addr[start / BITS_PER_LONG] ^ invert; - - /* Handle 1st word. */ - tmp &= ext2_swab(BITMAP_FIRST_WORD_MASK(start)); - start = round_down(start, BITS_PER_LONG); - - while (!tmp) { - start += BITS_PER_LONG; - if (start >= nbits) - return nbits; - - tmp = addr[start / BITS_PER_LONG] ^ invert; - } - - return min(start + __ffs(ext2_swab(tmp)), nbits); -} -#endif - -#ifndef find_next_zero_bit_le -unsigned long find_next_zero_bit_le(const void *addr, unsigned - long size, unsigned long offset) -{ - return _find_next_bit_le(addr, size, offset, ~0UL); -} -EXPORT_SYMBOL(find_next_zero_bit_le); -#endif - -#ifndef find_next_bit_le -unsigned long find_next_bit_le(const void *addr, unsigned - long size, unsigned long offset) -{ - return _find_next_bit_le(addr, size, offset, 0UL); -} -EXPORT_SYMBOL(find_next_bit_le); -#endif - -#endif /* __BIG_ENDIAN */ |