[PATCH 5.1 029/122] parisc: Add memory barrier to asm pdc and sync instructions

Greg Kroah-Hartman
2019-05-23T19:27:40Z

From: Helge Deller <deller@gmx.de>

commit 2d94a832e246ac00fd32eec241e6f1aa6fbc5700 upstream.

Add compiler memory barriers to ensure the compiler doesn't reorder memory
operations around these instructions.

Cc: stable@vger.kernel.org # v4.20+
Fixes: 3847dab77421 ("parisc: Add alternative coding infrastructure")
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/parisc/include/asm/cache.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/parisc/include/asm/cache.h
+++ b/arch/parisc/include/asm/cache.h
@@ -56,10 +56,10 @@ void parisc_setup_cache_timing(void);
#define asm_io_fdc(addr) asm volatile("fdc %%r0(%0)" \
ALTERNATIVE(ALT_COND_NO_DCACHE, INSN_NOP) \
ALTERNATIVE(ALT_COND_NO_IOC_FDC, INSN_NOP) \
- : : "r" (addr))
+ : : "r" (addr) : "memory")
#define asm_io_sync() asm volatile("sync" \
ALTERNATIVE(ALT_COND_NO_DCACHE, INSN_NOP) \
- ALTERNATIVE(ALT_COND_NO_IOC_FDC, INSN_NOP) :: )
+ ALTERNATIVE(ALT_COND_NO_IOC_FDC, INSN_NOP) :::"memory")

#endif /* ! __ASSEMBLY__ */