diff options
Diffstat (limited to 'lib/find_bit.c')
| -rw-r--r-- | lib/find_bit.c | 59 |
1 files changed, 43 insertions, 16 deletions
diff --git a/lib/find_bit.c b/lib/find_bit.c index 6ed74f78380c..ee3df93ba69a 100644 --- a/lib/find_bit.c +++ b/lib/find_bit.c @@ -21,22 +21,29 @@ #include <linux/export.h> #include <linux/kernel.h> -#if !defined(find_next_bit) || !defined(find_next_zero_bit) +#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \ + !defined(find_next_and_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. + * This is a common helper function for find_next_bit, find_next_zero_bit, and + * find_next_and_bit. The differences are: + * - The "invert" argument, which is XORed with each fetched word before + * searching it for one bits. + * - The optional "addr2", which is anded with "addr1" if present. */ -static unsigned long _find_next_bit(const unsigned long *addr, - unsigned long nbits, unsigned long start, unsigned long invert) +static inline unsigned long _find_next_bit(const unsigned long *addr1, + const unsigned long *addr2, unsigned long nbits, + unsigned long start, unsigned long invert) { unsigned long tmp; if (unlikely(start >= nbits)) return nbits; - tmp = addr[start / BITS_PER_LONG] ^ invert; + tmp = addr1[start / BITS_PER_LONG]; + if (addr2) + tmp &= addr2[start / BITS_PER_LONG]; + tmp ^= invert; /* Handle 1st word. */ tmp &= BITMAP_FIRST_WORD_MASK(start); @@ -47,7 +54,10 @@ static unsigned long _find_next_bit(const unsigned long *addr, if (start >= nbits) return nbits; - tmp = addr[start / BITS_PER_LONG] ^ invert; + tmp = addr1[start / BITS_PER_LONG]; + if (addr2) + tmp &= addr2[start / BITS_PER_LONG]; + tmp ^= invert; } return min(start + __ffs(tmp), nbits); @@ -61,7 +71,7 @@ static unsigned long _find_next_bit(const unsigned long *addr, unsigned long find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset) { - return _find_next_bit(addr, size, offset, 0UL); + return _find_next_bit(addr, NULL, size, offset, 0UL); } EXPORT_SYMBOL(find_next_bit); #endif @@ -70,11 +80,21 @@ EXPORT_SYMBOL(find_next_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); + return _find_next_bit(addr, NULL, size, offset, ~0UL); } EXPORT_SYMBOL(find_next_zero_bit); #endif +#if !defined(find_next_and_bit) +unsigned long find_next_and_bit(const unsigned long *addr1, + const unsigned long *addr2, unsigned long size, + unsigned long offset) +{ + return _find_next_bit(addr1, addr2, size, offset, 0UL); +} +EXPORT_SYMBOL(find_next_and_bit); +#endif + #ifndef find_first_bit /* * Find the first set bit in a memory region. @@ -146,15 +166,19 @@ static inline unsigned long ext2_swab(const unsigned long y) } #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) +static inline unsigned long _find_next_bit_le(const unsigned long *addr1, + const unsigned long *addr2, unsigned long nbits, + unsigned long start, unsigned long invert) { unsigned long tmp; if (unlikely(start >= nbits)) return nbits; - tmp = addr[start / BITS_PER_LONG] ^ invert; + tmp = addr1[start / BITS_PER_LONG]; + if (addr2) + tmp &= addr2[start / BITS_PER_LONG]; + tmp ^= invert; /* Handle 1st word. */ tmp &= ext2_swab(BITMAP_FIRST_WORD_MASK(start)); @@ -165,7 +189,10 @@ static unsigned long _find_next_bit_le(const unsigned long *addr, if (start >= nbits) return nbits; - tmp = addr[start / BITS_PER_LONG] ^ invert; + tmp = addr1[start / BITS_PER_LONG]; + if (addr2) + tmp &= addr2[start / BITS_PER_LONG]; + tmp ^= invert; } return min(start + __ffs(ext2_swab(tmp)), nbits); @@ -176,7 +203,7 @@ static unsigned long _find_next_bit_le(const unsigned long *addr, 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); + return _find_next_bit_le(addr, NULL, size, offset, ~0UL); } EXPORT_SYMBOL(find_next_zero_bit_le); #endif @@ -185,7 +212,7 @@ EXPORT_SYMBOL(find_next_zero_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); + return _find_next_bit_le(addr, NULL, size, offset, 0UL); } EXPORT_SYMBOL(find_next_bit_le); #endif |