MdePkg/Library/BaseLib/Ia32/ReadTsc.c

   1 /** @file
   2   AsmReadTsc function
   3
   4   Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9
  10
  11
  12 /**
  13   Reads the current value of Time Stamp Counter (TSC).
  14
  15   Reads and returns the current value of TSC. This function is only available
  16   on IA-32 and x64.
  17
  18   @return The current value of TSC
  19
  20 **/
  21 UINT64
  22 EFIAPI
  23 AsmReadTsc (
  24   VOID
  25   )
  26 {
  27   _asm {
  28     rdtsc
  29   }
  30 }
  31