diff options
Diffstat (limited to 'arch/ia64/lib/bitop.c')
-rw-r--r-- | arch/ia64/lib/bitop.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/ia64/lib/bitop.c b/arch/ia64/lib/bitop.c new file mode 100644 index 00000000000..82e299c8464 --- /dev/null +++ b/arch/ia64/lib/bitop.c @@ -0,0 +1,88 @@ +#include <linux/compiler.h> +#include <linux/types.h> +#include <asm/intrinsics.h> +#include <linux/module.h> +#include <linux/bitops.h> + +/* + * Find next zero bit in a bitmap reasonably efficiently.. + */ + +int __find_next_zero_bit (const void *addr, unsigned long size, unsigned long offset) +{ + unsigned long *p = ((unsigned long *) addr) + (offset >> 6); + unsigned long result = offset & ~63UL; + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 63UL; + if (offset) { + tmp = *(p++); + tmp |= ~0UL >> (64-offset); + if (size < 64) + goto found_first; + if (~tmp) + goto found_middle; + size -= 64; + result += 64; + } + while (size & ~63UL) { + if (~(tmp = *(p++))) + goto found_middle; + result += 64; + size -= 64; + } + if (!size) + return result; + tmp = *p; +found_first: + tmp |= ~0UL << size; + if (tmp == ~0UL) /* any bits zero? */ + return result + size; /* nope */ +found_middle: + return result + ffz(tmp); +} +EXPORT_SYMBOL(__find_next_zero_bit); + +/* + * Find next bit in a bitmap reasonably efficiently.. + */ +int __find_next_bit(const void *addr, unsigned long size, unsigned long offset) +{ + unsigned long *p = ((unsigned long *) addr) + (offset >> 6); + unsigned long result = offset & ~63UL; + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 63UL; + if (offset) { + tmp = *(p++); + tmp &= ~0UL << offset; + if (size < 64) + goto found_first; + if (tmp) + goto found_middle; + size -= 64; + result += 64; + } + while (size & ~63UL) { + if ((tmp = *(p++))) + goto found_middle; + result += 64; + size -= 64; + } + if (!size) + return result; + tmp = *p; + found_first: + tmp &= ~0UL >> (64-size); + if (tmp == 0UL) /* Are any bits set? */ + return result + size; /* Nope. */ + found_middle: + return result + __ffs(tmp); +} +EXPORT_SYMBOL(__find_next_bit); |