x86/locking: Use sfence for wmb() if SSE is available

When adding cc clobber to wmb()'s definition, the alternative()
condition to use sfence was incorrectly raised from X86_FEATURE_XMM to
X86_FEATURE_XMM2.

Restore the correct constraint for potential better performance on
machines without SSE2.

Fixes: bd922477d9 ("locking/x86: Add cc clobber for ADDL")
Signed-off-by: Yao Zi <me@ziyao.cc>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260801182953.15069-1-me@ziyao.cc
This commit is contained in:
Yao Zi 2026-08-01 18:29:53 +00:00 • committed by Peter Zijlstra
commit d824ed1307