xref: /openbmc/linux/arch/riscv/include/asm/barrier.h (revision bbecb07f)
1 /*
2  * Based on arch/arm/include/asm/barrier.h
3  *
4  * Copyright (C) 2012 ARM Ltd.
5  * Copyright (C) 2013 Regents of the University of California
6  * Copyright (C) 2017 SiFive
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #ifndef _ASM_RISCV_BARRIER_H
22 #define _ASM_RISCV_BARRIER_H
23 
24 #ifndef __ASSEMBLY__
25 
26 #define nop()		__asm__ __volatile__ ("nop")
27 
28 #define RISCV_FENCE(p, s) \
29 	__asm__ __volatile__ ("fence " #p "," #s : : : "memory")
30 
31 /* These barriers need to enforce ordering on both devices or memory. */
32 #define mb()		RISCV_FENCE(iorw,iorw)
33 #define rmb()		RISCV_FENCE(ir,ir)
34 #define wmb()		RISCV_FENCE(ow,ow)
35 
36 /* These barriers do not need to enforce ordering on devices, just memory. */
37 #define smp_mb()	RISCV_FENCE(rw,rw)
38 #define smp_rmb()	RISCV_FENCE(r,r)
39 #define smp_wmb()	RISCV_FENCE(w,w)
40 
41 #include <asm-generic/barrier.h>
42 
43 #endif /* __ASSEMBLY__ */
44 
45 #endif /* _ASM_RISCV_BARRIER_H */
46