linux-brain/arch/arc/include/asm/barrier.h
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

52 lines
1.6 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")
#elif !defined(CONFIG_ARC_PLAT_EZNPS) /* CONFIG_ISA_ARCOMPACT */
/*
* 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")
#else /* CONFIG_ARC_PLAT_EZNPS */
#include <plat/ctop.h>
#define mb() asm volatile (".word %0" : : "i"(CTOP_INST_SCHD_RW) : "memory")
#define rmb() asm volatile (".word %0" : : "i"(CTOP_INST_SCHD_RD) : "memory")
#endif
#include <asm-generic/barrier.h>
#endif