From: Guo Ren <guo...@linux.alibaba.com> We don't have native hw xchg16 instruction, so let qspinlock generic code to deal with it.
Using the full-word atomic xchg instructions implement xchg16 has the semantic risk for atomic operations. This patch cancels the dependency of on qspinlock generic code on architecture's xchg16. Also no need when PPC_LBARX_LWARX is enabled, see the link below. Signed-off-by: Guo Ren <guo...@linux.alibaba.com> Link: https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20201107032328.2454582-1-npig...@gmail.com/ Cc: Christophe Leroy <christophe.le...@csgroup.eu> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Paul Mackerras <pau...@samba.org> --- arch/powerpc/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 386ae12d8523..6133ad51690e 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -151,6 +151,7 @@ config PPC select ARCH_USE_CMPXCHG_LOCKREF if PPC64 select ARCH_USE_QUEUED_RWLOCKS if PPC_QUEUED_SPINLOCKS select ARCH_USE_QUEUED_SPINLOCKS if PPC_QUEUED_SPINLOCKS + select ARCH_USE_QUEUED_SPINLOCKS_XCHG32 if PPC_QUEUED_SPINLOCKS && !PPC_LBARX_LWARX select ARCH_WANT_IPC_PARSE_VERSION select ARCH_WANT_IRQS_OFF_ACTIVATE_MM select ARCH_WANT_LD_ORPHAN_WARN -- 2.17.1
