[PATCH 4.19 223/234] RISC-V: fix barrier() use in <vdso/processor.h>

[Greg Kroah-Hartman]

From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

commit 30aca1bacb398dec6c1ed5eeca33f355bd7b6203 upstream.

riscv's <vdso/processor.h> uses barrier() so it should include
<asm/barrier.h>

Fixes this build error:
  CC [M]  drivers/net/ethernet/emulex/benet/be_main.o
In file included from ./include/vdso/processor.h:10,
                 from ./arch/riscv/include/asm/processor.h:11,
                 from ./include/linux/prefetch.h:15,
                 from drivers/net/ethernet/emulex/benet/be_main.c:14:
./arch/riscv/include/asm/vdso/processor.h: In function 'cpu_relax':
./arch/riscv/include/asm/vdso/processor.h:14:2: error: implicit declaration of function 'barrier' [-Werror=implicit-function-declaration]
   14 |  barrier();

This happens with a total of 5 networking drivers -- they all use
<linux/prefetch.h>.

rv64 allmodconfig now builds cleanly after this patch.

Fixes fallout from:
815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive")

Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Reported-by: Andreas Schwab <schwab@xxxxxxxxxxxxxx>
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Acked-by: Arvind Sankar <nivedita@xxxxxxxxxxxx>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
[sudip: change in old path]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/riscv/include/asm/processor.h |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -30,6 +30,8 @@
 
 #ifndef __ASSEMBLY__
 
+#include <asm/barrier.h>
+
 struct task_struct;
 struct pt_regs;