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

[mirror_edk2.git] / UefiCpuPkg / PiSmmCpuDxeSmm / SyncTimer.c

/** @file\r
SMM Timer feature support\r
\r
Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "PiSmmCpuDxeSmm.h"\r
\r
UINT64  mTimeoutTicker = 0;\r
//\r
//  Number of counts in a roll-over cycle of the performance counter.\r
//\r
UINT64  mCycle = 0;\r
//\r
// Flag to indicate the performance counter is count-up or count-down.\r
//\r
BOOLEAN  mCountDown;\r
\r
/**\r
  Initialize Timer for SMM AP Sync.\r
\r
**/\r
VOID\r
InitializeSmmTimer (\r
  VOID\r
  )\r
{\r
  UINT64  TimerFrequency;\r
  UINT64  Start;\r
  UINT64  End;\r
\r
  TimerFrequency = GetPerformanceCounterProperties (&Start, &End);\r
  mTimeoutTicker = DivU64x32 (\r
                     MultU64x64 (TimerFrequency, PcdGet64 (PcdCpuSmmApSyncTimeout)),\r
                     1000 * 1000\r
                     );\r
  if (End < Start) {\r
    mCountDown = TRUE;\r
    mCycle     = Start - End;\r
  } else {\r
    mCountDown = FALSE;\r
    mCycle     = End - Start;\r
  }\r
}\r
\r
/**\r
  Start Timer for SMM AP Sync.\r
\r
**/\r
UINT64\r
EFIAPI\r
StartSyncTimer (\r
  VOID\r
  )\r
{\r
  return GetPerformanceCounter ();\r
}\r
\r
/**\r
  Check if the SMM AP Sync timer is timeout.\r
\r
  @param Timer  The start timer from the begin.\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
IsSyncTimerTimeout (\r
  IN      UINT64  Timer\r
  )\r
{\r
  UINT64  CurrentTimer;\r
  UINT64  Delta;\r
\r
  CurrentTimer = GetPerformanceCounter ();\r
  //\r
  // We need to consider the case that CurrentTimer is equal to Timer\r
  // when some timer runs too slow and CPU runs fast. We think roll over\r
  // condition does not happen on this case.\r
  //\r
  if (mCountDown) {\r
    //\r
    // The performance counter counts down.  Check for roll over condition.\r
    //\r
    if (CurrentTimer <= Timer) {\r
      Delta = Timer - CurrentTimer;\r
    } else {\r
      //\r
      // Handle one roll-over.\r
      //\r
      Delta = mCycle - (CurrentTimer - Timer) + 1;\r
    }\r
  } else {\r
    //\r
    // The performance counter counts up.  Check for roll over condition.\r
    //\r
    if (CurrentTimer >= Timer) {\r
      Delta = CurrentTimer - Timer;\r
    } else {\r
      //\r
      // Handle one roll-over.\r
      //\r
      Delta = mCycle - (Timer - CurrentTimer) + 1;\r
    }\r
  }\r
\r
  return (BOOLEAN)(Delta >= mTimeoutTicker);\r
}\r