diff options
| -rw-r--r-- | lib/find_bit.c | 49 |
1 files changed, 24 insertions, 25 deletions
diff --git a/lib/find_bit.c b/lib/find_bit.c index 1b8e4b2a9cba..894b656f6836 100644 --- a/lib/find_bit.c +++ b/lib/find_bit.c @@ -19,6 +19,27 @@ #include <linux/minmax.h> #include <linux/swab.h> +/* + * Common helper for find_bit() function family + * @FETCH: The expression that fetches and pre-processes each word of bitmap(s) + * @MUNGE: The expression that post-processes a word containing found bit (may be empty) + * @size: The bitmap size in bits + */ +#define FIND_FIRST_BIT(FETCH, MUNGE, size) \ +({ \ + unsigned long idx, val, sz = (size); \ + \ + for (idx = 0; idx * BITS_PER_LONG < sz; idx++) { \ + val = (FETCH); \ + if (val) { \ + sz = min(idx * BITS_PER_LONG + __ffs(MUNGE(val)), sz); \ + break; \ + } \ + } \ + \ + sz; \ +}) + #if !defined(find_next_bit) || !defined(find_next_zero_bit) || \ !defined(find_next_bit_le) || !defined(find_next_zero_bit_le) || \ !defined(find_next_and_bit) @@ -77,14 +98,7 @@ EXPORT_SYMBOL(_find_next_bit); */ 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; + return FIND_FIRST_BIT(addr[idx], /* nop */, size); } EXPORT_SYMBOL(_find_first_bit); #endif @@ -97,15 +111,7 @@ unsigned long _find_first_and_bit(const unsigned long *addr1, const unsigned long *addr2, unsigned long size) { - unsigned long idx, val; - - for (idx = 0; idx * BITS_PER_LONG < size; idx++) { - val = addr1[idx] & addr2[idx]; - if (val) - return min(idx * BITS_PER_LONG + __ffs(val), size); - } - - return size; + return FIND_FIRST_BIT(addr1[idx] & addr2[idx], /* nop */, size); } EXPORT_SYMBOL(_find_first_and_bit); #endif @@ -116,14 +122,7 @@ EXPORT_SYMBOL(_find_first_and_bit); */ 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; + return FIND_FIRST_BIT(~addr[idx], /* nop */, size); } EXPORT_SYMBOL(_find_first_zero_bit); #endif |