MdePkg/Library/BaseS3StallLib/S3StallLib.c

   1 /** @file
   2   Stall Services that do stall and also enable the Stall operatation
   3   to be replayed during an S3 resume. This library class maps directly on top
   4   of the Timer class.
   5
   6   Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved.<BR>
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include <Base.h>
  13
  14 #include <Library/TimerLib.h>
  15 #include <Library/DebugLib.h>
  16 #include <Library/S3BootScriptLib.h>
  17 #include <Library/S3StallLib.h>
  18
  19
  20 /**
  21   Stalls the CPU for at least the given number of microseconds and and saves
  22   the value in the S3 script to be replayed on S3 resume.
  23
  24   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  25
  26   @param  MicroSeconds  The minimum number of microseconds to delay.
  27
  28   @return MicroSeconds
  29
  30 **/
  31 UINTN
  32 EFIAPI
  33 S3Stall (
  34   IN UINTN                     MicroSeconds
  35   )
  36 {
  37   RETURN_STATUS    Status;
  38
  39   Status = S3BootScriptSaveStall (MicroSecondDelay (MicroSeconds));
  40   ASSERT (Status == RETURN_SUCCESS);
  41
  42   return MicroSeconds;
  43 }
  44
  45