From: Vivian Wang Date: Tue, 18 Nov 2025 04:19:23 +0000 (-0700) Subject: riscv: cmpxchg: Use riscv_has_extension_likely X-Git-Tag: v6.19-rc1~105^2~11 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=724c69447975e1e0854082c324b6871c8e2214f8;p=thirdparty%2Fkernel%2Flinux.git riscv: cmpxchg: Use riscv_has_extension_likely Use riscv_has_extension_likely() to check for RISCV_ISA_EXT_ZAWRS, replacing the use of asm goto with ALTERNATIVE. The "likely" variant is used to match the behavior of the original implementation using ALTERNATIVE("j %l[no_zawrs]", "nop", ...). Signed-off-by: Vivian Wang Link: https://patch.msgid.link/20251020-riscv-altn-helper-wip-v4-5-ef941c87669a@iscas.ac.cn Signed-off-by: Paul Walmsley --- diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index 122e1485d39a0..8712cf9c69dcb 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -373,9 +373,10 @@ static __always_inline void __cmpwait(volatile void *ptr, u32 *__ptr32b; ulong __s, __val, __mask; - asm goto(ALTERNATIVE("j %l[no_zawrs]", "nop", - 0, RISCV_ISA_EXT_ZAWRS, 1) - : : : : no_zawrs); + if (!riscv_has_extension_likely(RISCV_ISA_EXT_ZAWRS)) { + ALT_RISCV_PAUSE(); + return; + } switch (size) { case 1: @@ -437,11 +438,6 @@ static __always_inline void __cmpwait(volatile void *ptr, default: BUILD_BUG(); } - - return; - -no_zawrs: - ALT_RISCV_PAUSE(); } #define __cmpwait_relaxed(ptr, val) \