audk/MdePkg/Library/BaseLib/Ia32/FlushCacheLine.c
Michael D Kinney 9344f09215 MdePkg: Replace BSD License with BSD+Patent License
https://bugzilla.tianocore.org/show_bug.cgi?id=1373

Replace BSD 2-Clause License with BSD+Patent License.  This change is
based on the following emails:

  https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html
  https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html

RFCs with detailed process for the license change:

  V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html
  V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html
  V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
2019-04-09 10:58:13 -07:00

53 lines
1.2 KiB
C

/** @file
AsmFlushCacheLine function
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
/**
Flushes a cache line from all the instruction and data caches within the
coherency domain of the CPU.
Flushed the cache line specified by LinearAddress, and returns LinearAddress.
This function is only available on IA-32 and x64.
@param LinearAddress The address of the cache line to flush. If the CPU is
in a physical addressing mode, then LinearAddress is a
physical address. If the CPU is in a virtual
addressing mode, then LinearAddress is a virtual
address.
@return LinearAddress
**/
VOID *
EFIAPI
AsmFlushCacheLine (
IN VOID *LinearAddress
)
{
//
// If the CPU does not support CLFLUSH instruction,
// then promote flush range to flush entire cache.
//
_asm {
mov eax, 1
cpuid
test edx, BIT19
jz NoClflush
mov eax, dword ptr [LinearAddress]
clflush [eax]
jmp Done
NoClflush:
wbinvd
Done:
}
return LinearAddress;
}