[PATCH 5.0 025/139] parisc: Add memory barrier to asm pdc and sync instructions

[Greg Kroah-Hartman]

From: Helge Deller <deller@xxxxxx>

commit 2d94a832e246ac00fd32eec241e6f1aa6fbc5700 upstream.

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

Cc: stable@xxxxxxxxxxxxxxx # v4.20+
Fixes: 3847dab77421 ("parisc: Add alternative coding infrastructure")
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 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__ */