UefiCpuPkg: Move AsmRelocateApLoopStart from Mpfuncs.nasm to AmdSev.nasm

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / FlushCacheLine.c

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