ArmVirtPkg: reinstate timer unmask quirk for Xen

[mirror_edk2.git] / ArmVirtPkg / Library / XenArmGenericTimerVirtCounterLib / XenArmGenericTimerVirtCounterLib.c

/** @file\r
\r
  Copyright (c) 2011 - 2014, ARM Ltd. All rights reserved.<BR>\r
  Copyright (c) 2014 - 2018, Linaro Ltd. All rights reserved.<BR>\r
\r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include <Library/ArmGenericTimerCounterLib.h>\r
#include <Library/ArmLib.h>\r
\r
VOID\r
EFIAPI\r
ArmGenericTimerEnableTimer (\r
  VOID\r
  )\r
{\r
  UINTN TimerCtrlReg;\r
\r
  TimerCtrlReg = ArmReadCntvCtl ();\r
  TimerCtrlReg |= ARM_ARCH_TIMER_ENABLE;\r
  ArmWriteCntvCtl (TimerCtrlReg);\r
}\r
\r
VOID\r
EFIAPI\r
ArmGenericTimerReenableTimer (\r
  VOID\r
  )\r
{\r
  UINTN TimerCtrlReg;\r
\r
  TimerCtrlReg = ArmReadCntvCtl ();\r
  TimerCtrlReg |= ARM_ARCH_TIMER_ENABLE;\r
\r
  //\r
  // When running under Xen, we need to unmask the interrupt on the timer side\r
  // as Xen will mask it when servicing the interrupt at the hypervisor level\r
  // and delivering the virtual timer interrupt to the guest. Otherwise, the\r
  // interrupt will fire again, trapping into the hypervisor again, etc. etc.\r
  //\r
  TimerCtrlReg &= ~ARM_ARCH_TIMER_IMASK;\r
  ArmWriteCntvCtl (TimerCtrlReg);\r
}\r
\r
VOID\r
EFIAPI\r
ArmGenericTimerDisableTimer (\r
  VOID\r
  )\r
{\r
  UINTN TimerCtrlReg;\r
\r
  TimerCtrlReg = ArmReadCntvCtl ();\r
  TimerCtrlReg &= ~ARM_ARCH_TIMER_ENABLE;\r
  ArmWriteCntvCtl (TimerCtrlReg);\r
}\r
\r
VOID\r
EFIAPI\r
ArmGenericTimerSetTimerFreq (\r
  IN   UINTN  FreqInHz\r
  )\r
{\r
  ArmWriteCntFrq (FreqInHz);\r
}\r
\r
UINTN\r
EFIAPI\r
ArmGenericTimerGetTimerFreq (\r
  VOID\r
  )\r
{\r
  return ArmReadCntFrq ();\r
}\r
\r
UINTN\r
EFIAPI\r
ArmGenericTimerGetTimerVal (\r
  VOID\r
  )\r
{\r
  return ArmReadCntvTval ();\r
}\r
\r
\r
VOID\r
EFIAPI\r
ArmGenericTimerSetTimerVal (\r
  IN   UINTN   Value\r
  )\r
{\r
  ArmWriteCntvTval (Value);\r
}\r
\r
UINT64\r
EFIAPI\r
ArmGenericTimerGetSystemCount (\r
  VOID\r
  )\r
{\r
  return ArmReadCntvCt ();\r
}\r
\r
UINTN\r
EFIAPI\r
ArmGenericTimerGetTimerCtrlReg (\r
  VOID\r
  )\r
{\r
  return ArmReadCntvCtl ();\r
}\r
\r
VOID\r
EFIAPI\r
ArmGenericTimerSetTimerCtrlReg (\r
  UINTN Value\r
  )\r
{\r
  ArmWriteCntvCtl (Value);\r
}\r
\r
UINT64\r
EFIAPI\r
ArmGenericTimerGetCompareVal (\r
  VOID\r
  )\r
{\r
  return ArmReadCntvCval ();\r
}\r
\r
VOID\r
EFIAPI\r
ArmGenericTimerSetCompareVal (\r
  IN   UINT64   Value\r
  )\r
{\r
  ArmWriteCntvCval (Value);\r
}\r