Even though the static inline functions are __attribute__((const)) you can't use them in constant expressions. Make is_power_of_2() a constant expression if possible. Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Christian König <christian.koenig@xxxxxxx> Cc: David Gow <davidgow@xxxxxxxxxx> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> --- include/linux/log2.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/include/linux/log2.h b/include/linux/log2.h index 4027d1eecd7f..447a85102de0 100644 --- a/include/linux/log2.h +++ b/include/linux/log2.h @@ -56,9 +56,11 @@ bool __is_power_of_2(unsigned long n) * Return: true if @n is a power of 2, otherwise false. */ #define is_power_of_2(n) \ - __builtin_choose_expr(sizeof(n) > sizeof(unsigned long), \ - __is_power_of_2_ull(n), \ - __is_power_of_2(n)) + __builtin_choose_expr(__is_constexpr(n), \ + __IS_POWER_OF_2(n), \ + __builtin_choose_expr(sizeof(n) > sizeof(unsigned long), \ + __is_power_of_2_ull(n), \ + __is_power_of_2(n))) /** * __roundup_pow_of_two() - round up to nearest power of two -- 2.39.2
