[PATCH 6.18 253/752] openrisc: define arch-specific version of nop()

Sasha Levin
2026-02-28T17:51:41Z

From: Brian Masney <bmasney@redhat.com>

[ Upstream commit 0dfffa5479d6260d04d021f69203b1926f73d889 ]

When compiling a driver written for MIPS on OpenRISC that uses the nop()
function, it fails due to the following error:

drivers/watchdog/pic32-wdt.c: Assembler messages:
drivers/watchdog/pic32-wdt.c:125: Error: unrecognized instruction `nop'

The driver currently uses the generic version of nop() from
include/asm-generic/barrier.h:

#ifndef nop
#define nop() asm volatile ("nop")
#endif

Let's fix this on OpenRISC by defining an architecture-specific version
of nop().

This was tested by performing an allmodconfig openrisc cross compile on
an aarch64 host.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202601180236.BVy480We-lkp@intel.com/
Signed-off-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/openrisc/include/asm/barrier.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/openrisc/include/asm/barrier.h b/arch/openrisc/include/asm/barrier.h
index 7538294721bed..8e592c9909023 100644
--- a/arch/openrisc/include/asm/barrier.h
+++ b/arch/openrisc/include/asm/barrier.h
@@ -4,6 +4,8 @@

#define mb() asm volatile ("l.msync" ::: "memory")

+#define nop() asm volatile ("l.nop")
+
#include <asm-generic/barrier.h>

#endif /* __ASM_BARRIER_H */
--
2.51.0