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

From: Randy Dunlap <[email-masked]>
Date: Mon, 16 Nov 2020 17:39:51 -0800

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 <[email-masked]>
Signed-off-by: Randy Dunlap <[email-masked]>
Acked-by: Arvind Sankar <[email-masked]>
Signed-off-by: Palmer Dabbelt <[email-masked]>
Reviewed-by: Nick Desaulniers <[email-masked]>
Signed-off-by: Palmer Dabbelt <[email-masked]>
[sudip: change in old path]
Signed-off-by: Sudip Mukherjee <[email-masked]>
---
 arch/riscv/include/asm/processor.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index c23578a37b44..fdcc34b4f65b 100644
--- 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;
 
-- 
2.30.2