1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2020 ARM Ltd.
*/
#ifndef __ASM_VDSO_PROCESSOR_H
#define __ASM_VDSO_PROCESSOR_H
#ifndef __ASSEMBLER__
#ifdef CONFIG_CPU_LOONGSON64
/*
* Loongson-3's SFB (Store-Fill-Buffer) may buffer writes indefinitely when a
* tight read loop is executed, because reads take priority over writes & the
* hardware (incorrectly) doesn't ensure that writes will eventually occur.
*
* Since spin loops of any kind should have a cpu_relax() in them, force an SFB
* flush from cpu_relax() such that any pending writes will become visible as
* expected.
*/
#define cpu_relax() smp_mb()
#else
#define cpu_relax() barrier()
#endif
#endif /* __ASSEMBLER__ */
#endif /* __ASM_VDSO_PROCESSOR_H */
|
