diff options
Diffstat (limited to 'include/linux/log2.h')
| -rw-r--r-- | include/linux/log2.h | 42 |
1 files changed, 23 insertions, 19 deletions
diff --git a/include/linux/log2.h b/include/linux/log2.h index c373295f359f..41a1ae010993 100644 --- a/include/linux/log2.h +++ b/include/linux/log2.h @@ -37,19 +37,23 @@ int __ilog2_u64(u64 n) } #endif -/* - * Determine whether some value is a power of two, where zero is +/** + * is_power_of_2() - check if a value is a power of two + * @n: the value to check + * + * Determine whether some value is a power of two, where zero is * *not* considered a power of two. + * Return: true if @n is a power of 2, otherwise false. */ - static inline __attribute__((const)) bool is_power_of_2(unsigned long n) { return (n != 0 && ((n & (n - 1)) == 0)); } -/* - * round up to nearest power of two +/** + * __roundup_pow_of_two() - round up to nearest power of two + * @n: value to round up */ static inline __attribute__((const)) unsigned long __roundup_pow_of_two(unsigned long n) @@ -57,8 +61,9 @@ unsigned long __roundup_pow_of_two(unsigned long n) return 1UL << fls_long(n - 1); } -/* - * round down to nearest power of two +/** + * __rounddown_pow_of_two() - round down to nearest power of two + * @n: value to round down */ static inline __attribute__((const)) unsigned long __rounddown_pow_of_two(unsigned long n) @@ -67,12 +72,12 @@ unsigned long __rounddown_pow_of_two(unsigned long n) } /** - * ilog2 - log of base 2 of 32-bit or a 64-bit unsigned value - * @n - parameter + * ilog2 - log base 2 of 32-bit or a 64-bit unsigned value + * @n: parameter * * constant-capable log of base 2 calculation * - this can be used to initialise global variables from constant data, hence - * the massive ternary operator construction + * the massive ternary operator construction * * selects the appropriately-sized optimised version depending on sizeof(n) */ @@ -150,7 +155,7 @@ unsigned long __rounddown_pow_of_two(unsigned long n) /** * roundup_pow_of_two - round the given value up to nearest power of two - * @n - parameter + * @n: parameter * * round the given value up to the nearest power of two * - the result is undefined when n == 0 @@ -167,7 +172,7 @@ unsigned long __rounddown_pow_of_two(unsigned long n) /** * rounddown_pow_of_two - round the given value down to nearest power of two - * @n - parameter + * @n: parameter * * round the given value down to the nearest power of two * - the result is undefined when n == 0 @@ -180,6 +185,12 @@ unsigned long __rounddown_pow_of_two(unsigned long n) __rounddown_pow_of_two(n) \ ) +static inline __attribute_const__ +int __order_base_2(unsigned long n) +{ + return n > 1 ? ilog2(n - 1) + 1 : 0; +} + /** * order_base_2 - calculate the (rounded up) base 2 order of the argument * @n: parameter @@ -193,13 +204,6 @@ unsigned long __rounddown_pow_of_two(unsigned long n) * ob2(5) = 3 * ... and so on. */ - -static inline __attribute_const__ -int __order_base_2(unsigned long n) -{ - return n > 1 ? ilog2(n - 1) + 1 : 0; -} - #define order_base_2(n) \ ( \ __builtin_constant_p(n) ? ( \ |