diff options
Diffstat (limited to 'lib/find_next_bit.c')
| -rw-r--r-- | lib/find_next_bit.c | 95 |
1 files changed, 78 insertions, 17 deletions
diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c index 78ccd73a884..0cbfc0b4398 100644 --- a/lib/find_next_bit.c +++ b/lib/find_next_bit.c @@ -10,20 +10,18 @@ */ #include <linux/bitops.h> -#include <linux/module.h> +#include <linux/export.h> #include <asm/types.h> #include <asm/byteorder.h> #define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) -/** - * find_next_bit - find the next set bit in a memory region - * @addr: The address to base the search on - * @offset: The bitnumber to start searching at - * @size: The maximum size to search +#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) + unsigned long offset) { const unsigned long *p = addr + BITOP_WORD(offset); unsigned long result = offset & ~(BITS_PER_LONG-1); @@ -60,15 +58,16 @@ found_first: found_middle: return result + __ffs(tmp); } - EXPORT_SYMBOL(find_next_bit); +#endif +#ifndef find_next_zero_bit /* * This implementation of find_{first,next}_zero_bit was stolen from * Linus' asm-alpha/bitops.h. */ unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, - unsigned long offset) + unsigned long offset) { const unsigned long *p = addr + BITOP_WORD(offset); unsigned long result = offset & ~(BITS_PER_LONG-1); @@ -105,8 +104,64 @@ found_first: found_middle: return result + ffz(tmp); } - 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) +{ + const unsigned long *p = addr; + unsigned long result = 0; + unsigned long tmp; + + while (size & ~(BITS_PER_LONG-1)) { + if ((tmp = *(p++))) + goto found; + result += BITS_PER_LONG; + size -= BITS_PER_LONG; + } + if (!size) + return result; + + tmp = (*p) & (~0UL >> (BITS_PER_LONG - size)); + if (tmp == 0UL) /* Are any bits set? */ + return result + size; /* Nope. */ +found: + return result + __ffs(tmp); +} +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) +{ + const unsigned long *p = addr; + unsigned long result = 0; + unsigned long tmp; + + while (size & ~(BITS_PER_LONG-1)) { + if (~(tmp = *(p++))) + goto found; + result += BITS_PER_LONG; + size -= BITS_PER_LONG; + } + if (!size) + return result; + + tmp = (*p) | (~0UL << size); + if (tmp == ~0UL) /* Are any bits zero? */ + return result + size; /* Nope. */ +found: + return result + ffz(tmp); +} +EXPORT_SYMBOL(find_first_zero_bit); +#endif #ifdef __BIG_ENDIAN @@ -134,15 +189,17 @@ static inline unsigned long ext2_swab(const unsigned long y) #endif } -unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, unsigned +#ifndef find_next_zero_bit_le +unsigned long find_next_zero_bit_le(const void *addr, unsigned long size, unsigned long offset) { - const unsigned long *p = addr + BITOP_WORD(offset); + const unsigned long *p = addr; unsigned long result = offset & ~(BITS_PER_LONG - 1); unsigned long tmp; if (offset >= size) return size; + p += BITOP_WORD(offset); size -= result; offset &= (BITS_PER_LONG - 1UL); if (offset) { @@ -175,18 +232,20 @@ found_middle: found_middle_swap: return result + ffz(ext2_swab(tmp)); } +EXPORT_SYMBOL(find_next_zero_bit_le); +#endif -EXPORT_SYMBOL(generic_find_next_zero_le_bit); - -unsigned long generic_find_next_le_bit(const unsigned long *addr, unsigned +#ifndef find_next_bit_le +unsigned long find_next_bit_le(const void *addr, unsigned long size, unsigned long offset) { - const unsigned long *p = addr + BITOP_WORD(offset); + const unsigned long *p = addr; unsigned long result = offset & ~(BITS_PER_LONG - 1); unsigned long tmp; if (offset >= size) return size; + p += BITOP_WORD(offset); size -= result; offset &= (BITS_PER_LONG - 1UL); if (offset) { @@ -220,5 +279,7 @@ found_middle: found_middle_swap: return result + __ffs(ext2_swab(tmp)); } -EXPORT_SYMBOL(generic_find_next_le_bit); +EXPORT_SYMBOL(find_next_bit_le); +#endif + #endif /* __BIG_ENDIAN */ |