Subject: [PATCH v6 7/9] sparc: qspinlock: Add ARCH_USE_QUEUED_SPINLOCKS_XCHG32

From: [email-masked]
Date: Wed, 31 Mar 2021 14:30:38 +0000

From: Guo Ren <[email-masked]>

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.

Signed-off-by: Guo Ren <[email-masked]>
Cc: Arnd Bergmann <[email-masked]>
Cc: David S. Miller <[email-masked]>
Cc: Rob Gardner <[email-masked]>
---
 arch/sparc/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 164a5254c91c..1079fe3f058c 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -91,6 +91,7 @@ config SPARC64
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_USE_QUEUED_SPINLOCKS
+	select ARCH_USE_QUEUED_SPINLOCKS_XCHG32
 	select GENERIC_TIME_VSYSCALL
 	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_PTE_SPECIAL
-- 
2.17.1