.. | .. |
---|
| 1 | +/* SPDX-License-Identifier: GPL-2.0-only */ |
---|
1 | 2 | /* |
---|
2 | 3 | * X86 specific ACPICA environments and implementation |
---|
3 | 4 | * |
---|
4 | 5 | * Copyright (C) 2014, Intel Corporation |
---|
5 | 6 | * Author: Lv Zheng <lv.zheng@intel.com> |
---|
6 | | - * |
---|
7 | | - * This program is free software; you can redistribute it and/or modify |
---|
8 | | - * it under the terms of the GNU General Public License version 2 as |
---|
9 | | - * published by the Free Software Foundation. |
---|
10 | 7 | */ |
---|
11 | 8 | |
---|
12 | 9 | #ifndef _ASM_X86_ACENV_H |
---|
.. | .. |
---|
16 | 13 | |
---|
17 | 14 | /* Asm macros */ |
---|
18 | 15 | |
---|
19 | | -#define ACPI_FLUSH_CPU_CACHE() wbinvd() |
---|
| 16 | +/* |
---|
| 17 | + * ACPI_FLUSH_CPU_CACHE() flushes caches on entering sleep states. |
---|
| 18 | + * It is required to prevent data loss. |
---|
| 19 | + * |
---|
| 20 | + * While running inside virtual machine, the kernel can bypass cache flushing. |
---|
| 21 | + * Changing sleep state in a virtual machine doesn't affect the host system |
---|
| 22 | + * sleep state and cannot lead to data loss. |
---|
| 23 | + */ |
---|
| 24 | +#define ACPI_FLUSH_CPU_CACHE() \ |
---|
| 25 | +do { \ |
---|
| 26 | + if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR)) \ |
---|
| 27 | + wbinvd(); \ |
---|
| 28 | +} while (0) |
---|
20 | 29 | |
---|
21 | 30 | int __acpi_acquire_global_lock(unsigned int *lock); |
---|
22 | 31 | int __acpi_release_global_lock(unsigned int *lock); |
---|