Re: [PATCH] UefiCpuPkg: Restore HpetTimer after CpuExceptionHandlerLib test

["Ni, Ray" <ray.ni@intel.com>]

Reviewed-by: Ray Ni <ray.ni@intel.com>

> -----Original Message-----
> From: Tan, Dun <dun.tan@intel.com>
> Sent: Thursday, October 20, 2022 11:01 AM
> To: devel@edk2.groups.io
> Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar,
> Rahul R <rahul.r.kumar@intel.com>
> Subject: [PATCH] UefiCpuPkg: Restore HpetTimer after
> CpuExceptionHandlerLib test
> 
> Disable/Restore HpetTimer before and after running the Dxe
> CpuExceptionHandlerLib unit test module. During the UnitTest, a
> new Idt is initialized for the test. There is no handler for timer
> intrrupt in this new idt. After the test module, HpetTimer does
> not work any more since the comparator value register and main
> counter value register for timer does not match. To fix this issue,
> disable/restore HpetTimer before and after Unit Test if HpetTimer
> driver has been dispatched. Besides, send Apic EOI before restore
> HpetTimer.
> 
> Signed-off-by: Dun Tan <dun.tan@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Rahul Kumar <rahul1.kumar@intel.com>
> ---
> 
> UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionHan
> dlerLibUnitTest.inf |  2 ++
> 
> UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionHan
> dlerUnitTest.c      | 33 ++++++++++++++++++++++++++++++++-
>  2 files changed, 34 insertions(+), 1 deletion(-)
> 
> diff --git
> a/UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionH
> andlerLibUnitTest.inf
> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionH
> andlerLibUnitTest.inf
> index e3dbe7b9ab..24f905936c 100644
> ---
> a/UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionH
> andlerLibUnitTest.inf
> +++
> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionH
> andlerLibUnitTest.inf
> @@ -43,6 +43,7 @@
>    HobLib
>    UefiBootServicesTableLib
>    CpuPageTableLib
> +  LocalApicLib
> 
>  [Guids]
>    gEfiHobMemoryAllocStackGuid
> @@ -53,6 +54,7 @@
> 
>  [Protocols]
>    gEfiMpServiceProtocolGuid
> +  gEfiTimerArchProtocolGuid
> 
>  [Depex]
>    gEfiMpServiceProtocolGuid
> diff --git
> a/UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionH
> andlerUnitTest.c
> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionH
> andlerUnitTest.c
> index 917fc549bf..045f39fa00 100644
> ---
> a/UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionH
> andlerUnitTest.c
> +++
> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/UnitTest/DxeCpuExceptionH
> andlerUnitTest.c
> @@ -8,6 +8,8 @@
> 
>  #include "CpuExceptionHandlerTest.h"
>  #include <Library/UefiBootServicesTableLib.h>
> +#include <Library/LocalApicLib.h>
> +#include <Protocol/Timer.h>
> 
>  /**
>    Initialize Bsp Idt with a new Idt table and return the IA32_DESCRIPTOR
> buffer.
> @@ -162,8 +164,12 @@ CpuExceptionHandlerTestEntry (
>  {
>    EFI_STATUS                  Status;
>    UNIT_TEST_FRAMEWORK_HANDLE  Framework;
> +  EFI_TIMER_ARCH_PROTOCOL     *TimerArchProtocol;
> +  UINT64                      TimerPeriod;
> 
> -  Framework = NULL;
> +  Framework         = NULL;
> +  TimerArchProtocol = NULL;
> +  TimerPeriod       = 0;
> 
>    DEBUG ((DEBUG_INFO, "%a v%a\n", UNIT_TEST_APP_NAME,
> UNIT_TEST_APP_VERSION));
> 
> @@ -182,11 +188,36 @@ CpuExceptionHandlerTestEntry (
>      goto EXIT;
>    }
> 
> +  //
> +  // If HpetTimer driver has been dispatched, disable HpetTimer before Unit
> Test.
> +  //
> +  gBS->LocateProtocol (&gEfiTimerArchProtocolGuid, NULL, (VOID
> **)&TimerArchProtocol);
> +  if (TimerArchProtocol != NULL) {
> +    Status = TimerArchProtocol->GetTimerPeriod (TimerArchProtocol,
> &TimerPeriod);
> +    ASSERT_EFI_ERROR (Status);
> +    if (TimerPeriod > 0) {
> +      DEBUG ((DEBUG_INFO, "HpetTimer has been dispatched. Disable
> HpetTimer.\n"));
> +      Status = TimerArchProtocol->SetTimerPeriod (TimerArchProtocol, 0);
> +      ASSERT_EFI_ERROR (Status);
> +    }
> +  }
> +
>    //
>    // Execute the tests.
>    //
>    Status = RunAllTestSuites (Framework);
> 
> +  //
> +  // Restore HpetTimer after Unit Test.
> +  // Send APIC EOI before SetTimerPeriod.
> +  //
> +  if ((TimerArchProtocol != NULL) && (TimerPeriod > 0)) {
> +    DEBUG ((DEBUG_INFO, "Restore HpetTimer after
> DxeCpuExceptionHandlerLib UnitTest.\n"));
> +    SendApicEoi ();
> +    Status = TimerArchProtocol->SetTimerPeriod (TimerArchProtocol,
> TimerPeriod);
> +    ASSERT_EFI_ERROR (Status);
> +  }
> +
>  EXIT:
>    if (Framework) {
>      FreeUnitTestFramework (Framework);
> --
> 2.31.1.windows.1