1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
 
 
 
 
 4 */
 5
 6#ifndef __ASM_BARRIER_H
 7#define __ASM_BARRIER_H
 8
 9#ifdef CONFIG_ISA_ARCV2
10
11/*
12 * ARCv2 based HS38 cores are in-order issue, but still weakly ordered
13 * due to micro-arch buffering/queuing of load/store, cache hit vs. miss ...
14 *
15 * Explicit barrier provided by DMB instruction
16 *  - Operand supports fine grained load/store/load+store semantics
17 *  - Ensures that selected memory operation issued before it will complete
18 *    before any subsequent memory operation of same type
19 *  - DMB guarantees SMP as well as local barrier semantics
20 *    (asm-generic/barrier.h ensures sane smp_*mb if not defined here, i.e.
21 *    UP: barrier(), SMP: smp_*mb == *mb)
22 *  - DSYNC provides DMB+completion_of_cache_bpu_maintenance_ops hence not needed
23 *    in the general case. Plus it only provides full barrier.
24 */
25
26#define mb()	asm volatile("dmb 3\n" : : : "memory")
27#define rmb()	asm volatile("dmb 1\n" : : : "memory")
28#define wmb()	asm volatile("dmb 2\n" : : : "memory")
29
30#else
 
 
31
32/*
33 * ARCompact based cores (ARC700) only have SYNC instruction which is super
34 * heavy weight as it flushes the pipeline as well.
35 * There are no real SMP implementations of such cores.
36 */
37
38#define mb()	asm volatile("sync\n" : : : "memory")
39
40#endif
41
42#include <asm-generic/barrier.h>
43
44#endif

 
 1/*
 2 * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
 3 *
 4 * This program is free software; you can redistribute it and/or modify
 5 * it under the terms of the GNU General Public License version 2 as
 6 * published by the Free Software Foundation.
 7 */
 8
 9#ifndef __ASM_BARRIER_H
10#define __ASM_BARRIER_H
11
12#ifdef CONFIG_ISA_ARCV2
13
14/*
15 * ARCv2 based HS38 cores are in-order issue, but still weakly ordered
16 * due to micro-arch buffering/queuing of load/store, cache hit vs. miss ...
17 *
18 * Explicit barrier provided by DMB instruction
19 *  - Operand supports fine grained load/store/load+store semantics
20 *  - Ensures that selected memory operation issued before it will complete
21 *    before any subsequent memory operation of same type
22 *  - DMB guarantees SMP as well as local barrier semantics
23 *    (asm-generic/barrier.h ensures sane smp_*mb if not defined here, i.e.
24 *    UP: barrier(), SMP: smp_*mb == *mb)
25 *  - DSYNC provides DMB+completion_of_cache_bpu_maintenance_ops hence not needed
26 *    in the general case. Plus it only provides full barrier.
27 */
28
29#define mb()	asm volatile("dmb 3\n" : : : "memory")
30#define rmb()	asm volatile("dmb 1\n" : : : "memory")
31#define wmb()	asm volatile("dmb 2\n" : : : "memory")
32
33#endif
34
35#ifdef CONFIG_ISA_ARCOMPACT
36
37/*
38 * ARCompact based cores (ARC700) only have SYNC instruction which is super
39 * heavy weight as it flushes the pipeline as well.
40 * There are no real SMP implementations of such cores.
41 */
42
43#define mb()	asm volatile("sync\n" : : : "memory")
 
44#endif
45
46#include <asm-generic/barrier.h>
47
48#endif