diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h index fae152ea0508..c6bd3d8354a9 100644 --- a/arch/riscv/include/asm/bitops.h +++ b/arch/riscv/include/asm/bitops.h @@ -228,7 +228,7 @@ static __always_inline int variable_fls(unsigned int x) * * This operation may be reordered on other architectures than x86. */ -static inline int arch_test_and_set_bit(int nr, volatile unsigned long *addr) +static __always_inline int arch_test_and_set_bit(int nr, volatile unsigned long *addr) { return __test_and_op_bit(or, __NOP, nr, addr); } @@ -240,7 +240,7 @@ static inline int arch_test_and_set_bit(int nr, volatile unsigned long *addr) * * This operation can be reordered on other architectures other than x86. */ -static inline int arch_test_and_clear_bit(int nr, volatile unsigned long *addr) +static __always_inline int arch_test_and_clear_bit(int nr, volatile unsigned long *addr) { return __test_and_op_bit(and, __NOT, nr, addr); } @@ -253,7 +253,7 @@ static inline int arch_test_and_clear_bit(int nr, volatile unsigned long *addr) * This operation is atomic and cannot be reordered. * It also implies a memory barrier. */ -static inline int arch_test_and_change_bit(int nr, volatile unsigned long *addr) +static __always_inline int arch_test_and_change_bit(int nr, volatile unsigned long *addr) { return __test_and_op_bit(xor, __NOP, nr, addr); } @@ -270,7 +270,7 @@ static inline int arch_test_and_change_bit(int nr, volatile unsigned long *addr) * Note that @nr may be almost arbitrarily large; this function is not * restricted to acting on a single-word quantity. */ -static inline void arch_set_bit(int nr, volatile unsigned long *addr) +static __always_inline void arch_set_bit(int nr, volatile unsigned long *addr) { __op_bit(or, __NOP, nr, addr); } @@ -284,7 +284,7 @@ static inline void arch_set_bit(int nr, volatile unsigned long *addr) * on non x86 architectures, so if you are writing portable code, * make sure not to rely on its reordering guarantees. */ -static inline void arch_clear_bit(int nr, volatile unsigned long *addr) +static __always_inline void arch_clear_bit(int nr, volatile unsigned long *addr) { __op_bit(and, __NOT, nr, addr); } @@ -298,7 +298,7 @@ static inline void arch_clear_bit(int nr, volatile unsigned long *addr) * Note that @nr may be almost arbitrarily large; this function is not * restricted to acting on a single-word quantity. */ -static inline void arch_change_bit(int nr, volatile unsigned long *addr) +static __always_inline void arch_change_bit(int nr, volatile unsigned long *addr) { __op_bit(xor, __NOP, nr, addr); } @@ -311,7 +311,7 @@ static inline void arch_change_bit(int nr, volatile unsigned long *addr) * This operation is atomic and provides acquire barrier semantics. * It can be used to implement bit locks. */ -static inline int arch_test_and_set_bit_lock( +static __always_inline int arch_test_and_set_bit_lock( unsigned long nr, volatile unsigned long *addr) { return __test_and_op_bit_ord(or, __NOP, nr, addr, .aq); @@ -324,7 +324,7 @@ static inline int arch_test_and_set_bit_lock( * * This operation is atomic and provides release barrier semantics. */ -static inline void arch_clear_bit_unlock( +static __always_inline void arch_clear_bit_unlock( unsigned long nr, volatile unsigned long *addr) { __op_bit_ord(and, __NOT, nr, addr, .rl); @@ -345,13 +345,13 @@ static inline void arch_clear_bit_unlock( * non-atomic property here: it's a lot more instructions and we still have to * provide release semantics anyway. */ -static inline void arch___clear_bit_unlock( +static __always_inline void arch___clear_bit_unlock( unsigned long nr, volatile unsigned long *addr) { arch_clear_bit_unlock(nr, addr); } -static inline bool arch_xor_unlock_is_negative_byte(unsigned long mask, +static __always_inline bool arch_xor_unlock_is_negative_byte(unsigned long mask, volatile unsigned long *addr) { unsigned long res; diff --git a/include/linux/bits.h b/include/linux/bits.h index 60044b608817..61a75d3f294b 100644 --- a/include/linux/bits.h +++ b/include/linux/bits.h @@ -20,9 +20,8 @@ */ #if !defined(__ASSEMBLY__) #include -#define GENMASK_INPUT_CHECK(h, l) \ - (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \ - __is_constexpr((l) > (h)), (l) > (h), 0))) +#include +#define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h))) #else /* * BUILD_BUG_ON_ZERO is not available in h files included from asm files, diff --git a/include/linux/compiler.h b/include/linux/compiler.h index eac58025ecfc..b408ba81d01a 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -307,6 +307,28 @@ static inline void *offset_to_ptr(const int *off) */ #define statically_true(x) (__builtin_constant_p(x) && (x)) +/* + * Similar to statically_true() but produces a constant expression + * + * To be used in conjunction with macros, such as BUILD_BUG_ON_ZERO(), + * which require their input to be a constant expression and for which + * statically_true() would otherwise fail. + * + * This is a trade-off: const_true() requires all its operands to be + * compile time constants. Else, it would always returns false even on + * the most trivial cases like: + * + * true || non_const_var + * + * On the opposite, statically_true() is able to fold more complex + * tautologies and will return true on expressions such as: + * + * !(non_const_var * 8 % 4) + * + * For the general case, statically_true() is better. + */ +#define const_true(x) __builtin_choose_expr(__is_constexpr(x), x, false) + /* * This is needed in functions which generate the stack canary, see * arch/x86/kernel/smpboot.c::start_secondary() for an example.