riscv does not have lr instructions on byte and halfword but the qspinlock implementation actually uses such atomics provided by the Zabha extension, so those sizes are legitimate. Then instead of failing to build, just fallback to the !Zawrs path. Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx> --- arch/riscv/include/asm/cmpxchg.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index ebbce134917c..9ba497ea18a5 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -268,7 +268,8 @@ static __always_inline void __cmpwait(volatile void *ptr, break; #endif default: - BUILD_BUG(); + /* RISC-V doesn't have lr instructions on byte and half-word. */ + goto no_zawrs; } return; -- 2.39.2
