[PATCH 4.0 17/72] MIPS: asm: spinlock: Fix addiu instruction for R10000_LLSC_WAR case

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.0-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Markos Chandras <markos.chandras@imgtec.com>

Commit 518222161d4a2d3f3b2700098563b62383f83878 upstream.

Commit 5753762cbd1c("MIPS: asm: spinlock: Replace "sub" instruction
with "addiu") replaced the "sub" instruction with addiu but it did
not update the immediate value in the R10000_LLSC_WAR case.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Fixes: 5753762cbd1c("MIPS: asm: spinlock: Replace "sub" instruction with "addiu"")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9385/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/mips/include/asm/spinlock.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/include/asm/spinlock.h
+++ b/arch/mips/include/asm/spinlock.h
@@ -263,7 +263,7 @@ static inline void arch_read_unlock(arch
 	if (R10000_LLSC_WAR) {
 		__asm__ __volatile__(
 		"1:	ll	%1, %2		# arch_read_unlock	\n"
-		"	addiu	%1, 1					\n"
+		"	addiu	%1, -1					\n"
 		"	sc	%1, %0					\n"
 		"	beqzl	%1, 1b					\n"
 		: "=" GCC_OFF_SMALL_ASM() (rw->lock), "=&r" (tmp)