linux-stable/arch/arc/include/asm/barrier.h
Vineet Gupta dd7c7ab01a ARC: [plat-eznps]: Drop support for EZChip NPS platform
NPS customers are no longer doing active development, as evident from
rand config build failures reported in recent times, so drop support
for NPS platform.

Tested-by: kernel test robot <lkp@intel.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2020-10-05 21:02:29 -07:00

44 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
*/
#ifndef __ASM_BARRIER_H
#define __ASM_BARRIER_H
#ifdef CONFIG_ISA_ARCV2
/*
* ARCv2 based HS38 cores are in-order issue, but still weakly ordered
* due to micro-arch buffering/queuing of load/store, cache hit vs. miss ...
*
* Explicit barrier provided by DMB instruction
* - Operand supports fine grained load/store/load+store semantics
* - Ensures that selected memory operation issued before it will complete
* before any subsequent memory operation of same type
* - DMB guarantees SMP as well as local barrier semantics
* (asm-generic/barrier.h ensures sane smp_*mb if not defined here, i.e.
* UP: barrier(), SMP: smp_*mb == *mb)
* - DSYNC provides DMB+completion_of_cache_bpu_maintenance_ops hence not needed
* in the general case. Plus it only provides full barrier.
*/
#define mb() asm volatile("dmb 3\n" : : : "memory")
#define rmb() asm volatile("dmb 1\n" : : : "memory")
#define wmb() asm volatile("dmb 2\n" : : : "memory")
#else
/*
* ARCompact based cores (ARC700) only have SYNC instruction which is super
* heavy weight as it flushes the pipeline as well.
* There are no real SMP implementations of such cores.
*/
#define mb() asm volatile("sync\n" : : : "memory")
#endif
#include <asm-generic/barrier.h>
#endif