Hi Ray,

I updated the file names as suggested on the previous round. Do you have any further comments/feedback?

Thanks,

Kun

From: Kun Qin
Sent: Thursday, January 14, 2021 14:37
To: devel@edk2.groups.io
Cc: Ray Ni
Subject: [edk2-devel] [PATCH v3 12/18] PcAtChipsetPkg: AcpiTimerLib: Added StandaloneMm instance of AcpiTimerLib

This change added a new instance of AcpiTimerLib for StandaloneMm core
and drivers. It centralizes the common routines into shared files and
abstract the library constructor into corresponding files to accommodate
each constructor function prototypes.

Cc: Ray Ni <ray.ni@intel.com>

Signed-off-by: Kun Qin <kun.q@outlook.com>
---

Notes:
    v3:
    - Renamed "CommonAcpiTimerLib" to "DxeStandaloneMmAcpiTimerLib" to
    avoid confusion [Ray]
    - Renamed BASE NAME (and file name) to StandaloneMmAcpiTimerLib [Ray]

    v2:
    - Removed "EFIAPI" for internal functions.

 PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c                                     | 81 +-------------------
 PcAtChipsetPkg/Library/AcpiTimerLib/{DxeAcpiTimerLib.c => DxeStandaloneMmAcpiTimerLib.c}  |  9 +--
 PcAtChipsetPkg/Library/AcpiTimerLib/StandaloneMmAcpiTimerLib.c                            | 31 ++++++++
 PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf                                   |  2 +
 PcAtChipsetPkg/Library/AcpiTimerLib/DxeStandaloneMmAcpiTimerLib.h                         | 24 ++++++
 PcAtChipsetPkg/Library/AcpiTimerLib/{DxeAcpiTimerLib.inf => StandaloneMmAcpiTimerLib.inf} | 19 +++--
 PcAtChipsetPkg/PcAtChipsetPkg.dsc                                                         |  1 +
 7 files changed, 74 insertions(+), 93 deletions(-)

diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
index 3ad831b15e8a..9ac2a446e365 100644
--- a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
@@ -2,72 +2,14 @@
   ACPI Timer implements one instance of Timer Library.

   Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) Microsoft Corporation.
   SPDX-License-Identifier: BSD-2-Clause-Patent

 **/

 #include <PiDxe.h>
-#include <Library/TimerLib.h>
-#include <Library/BaseLib.h>
-#include <Library/HobLib.h>

-extern GUID mFrequencyHobGuid;
-
-/**
-  The constructor function enables ACPI IO space.
-
-  If ACPI I/O space not enabled, this function will enable it.
-  It will always return RETURN_SUCCESS.
-
-  @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
-
-**/
-RETURN_STATUS
-EFIAPI
-AcpiTimerLibConstructor (
-  VOID
-  );
-
-/**
-  Calculate TSC frequency.
-
-  The TSC counting frequency is determined by comparing how far it counts
-  during a 101.4 us period as determined by the ACPI timer.
-  The ACPI timer is used because it counts at a known frequency.
-  The TSC is sampled, followed by waiting 363 counts of the ACPI timer,
-  or 101.4 us. The TSC is then sampled again. The difference multiplied by
-  9861 is the TSC frequency. There will be a small error because of the
-  overhead of reading the ACPI timer. An attempt is made to determine and
-  compensate for this error.
-
-  @return The number of TSC counts per second.
-
-**/
-UINT64
-InternalCalculateTscFrequency (
-  VOID
-  );
-
-//
-// Cached performance counter frequency
-//
-UINT64  mPerformanceCounterFrequency = 0;
-
-/**
-  Internal function to retrieves the 64-bit frequency in Hz.
-
-  Internal function to retrieves the 64-bit frequency in Hz.
-
-  @return The frequency in Hz.
-
-**/
-UINT64
-InternalGetPerformanceCounterFrequency (
-  VOID
-  )
-{
-  return  mPerformanceCounterFrequency;
-}
+#include "DxeStandaloneMmAcpiTimerLib.h"

 /**
   The constructor function enables ACPI IO space, and caches PerformanceCounterFrequency.
@@ -85,22 +27,5 @@ DxeAcpiTimerLibConstructor (
   IN EFI_SYSTEM_TABLE  *SystemTable
   )
 {
-  EFI_HOB_GUID_TYPE   *GuidHob;
-
-  //
-  // Enable ACPI IO space.
-  //
-  AcpiTimerLibConstructor ();
-
-  //
-  // Initialize PerformanceCounterFrequency
-  //
-  GuidHob = GetFirstGuidHob (&mFrequencyHobGuid);
-  if (GuidHob != NULL) {
-    mPerformanceCounterFrequency = *(UINT64*)GET_GUID_HOB_DATA (GuidHob);
-  } else {
-    mPerformanceCounterFrequency = InternalCalculateTscFrequency ();
-  }
-
-  return EFI_SUCCESS;
+  return CommonAcpiTimerLibConstructor ();
 }
diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeStandaloneMmAcpiTimerLib.c
similarity index 86%
copy from PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
copy to PcAtChipsetPkg/Library/AcpiTimerLib/DxeStandaloneMmAcpiTimerLib.c
index 3ad831b15e8a..0e401194d01d 100644
--- a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeStandaloneMmAcpiTimerLib.c
@@ -72,17 +72,12 @@ InternalGetPerformanceCounterFrequency (
 /**
   The constructor function enables ACPI IO space, and caches PerformanceCounterFrequency.

-  @param  ImageHandle   The firmware allocated handle for the EFI image.
-  @param  SystemTable   A pointer to the EFI System Table.
-
   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.

 **/
 EFI_STATUS
-EFIAPI
-DxeAcpiTimerLibConstructor (
-  IN EFI_HANDLE        ImageHandle,
-  IN EFI_SYSTEM_TABLE  *SystemTable
+CommonAcpiTimerLibConstructor (
+  VOID
   )
 {
   EFI_HOB_GUID_TYPE   *GuidHob;
diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/StandaloneMmAcpiTimerLib.c b/PcAtChipsetPkg/Library/AcpiTimerLib/StandaloneMmAcpiTimerLib.c
new file mode 100644
index 000000000000..97aca5606905
--- /dev/null
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/StandaloneMmAcpiTimerLib.c
@@ -0,0 +1,31 @@
+/** @file
+  ACPI Timer implements one instance of Timer Library.
+
+  Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiMm.h>
+
+#include "DxeStandaloneMmAcpiTimerLib.h"
+
+/**
+  The constructor function enables ACPI IO space, and caches PerformanceCounterFrequency.
+
+  @param  ImageHandle   The firmware allocated handle for the EFI image.
+  @param  SystemTable   A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
+
+**/
+EFI_STATUS
+EFIAPI
+StandaloneMmAcpiTimerLibConstructor (
+  IN EFI_HANDLE           ImageHandle,
+  IN EFI_MM_SYSTEM_TABLE  *SystemTable
+  )
+{
+  return CommonAcpiTimerLibConstructor ();
+}
diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
index d86356f4ff17..93972e53c9c5 100644
--- a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
@@ -25,6 +25,8 @@ [Defines]
 [Sources]
   AcpiTimerLib.c
   DxeAcpiTimerLib.c
+  DxeStandaloneMmAcpiTimerLib.c
+  DxeStandaloneMmAcpiTimerLib.h

 [Packages]
   MdePkg/MdePkg.dec
diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeStandaloneMmAcpiTimerLib.h b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeStandaloneMmAcpiTimerLib.h
new file mode 100644
index 000000000000..6015d684e5bd
--- /dev/null
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeStandaloneMmAcpiTimerLib.h
@@ -0,0 +1,24 @@
+/** @file
+  Header file internal to ACPI TimerLib.
+
+Copyright (c) Microsoft Corporation.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#ifndef _DXE_STANDALONE_MM_ACPI_TIMER_LIB_H_
+#define _DXE_STANDALONE_MM_ACPI_TIMER_LIB_H_
+
+/**
+  The constructor function enables ACPI IO space, and caches PerformanceCounterFrequency.
+
+  @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
+
+**/
+EFI_STATUS
+CommonAcpiTimerLibConstructor (
+  VOID
+  );
+
+#endif
diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf b/PcAtChipsetPkg/Library/AcpiTimerLib/StandaloneMmAcpiTimerLib.inf
similarity index 70%
copy from PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
copy to PcAtChipsetPkg/Library/AcpiTimerLib/StandaloneMmAcpiTimerLib.inf
index d86356f4ff17..c5efdd145d19 100644
--- a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/StandaloneMmAcpiTimerLib.inf
@@ -1,5 +1,5 @@
 ## @file
-#  DXE ACPI Timer Library
+#  Standalone MM ACPI Timer Library
 #
 #  Provides basic timer support using the ACPI timer hardware.  The performance
 #  counter features are provided by the processors time stamp counter.
@@ -8,23 +8,26 @@
 #  is compatible with both 24-bit and 32-bit ACPI timers.
 #
 #  Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) Microsoft Corporation.
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
 ##

 [Defines]
   INF_VERSION                    = 0x00010005
-  BASE_NAME                      = DxeAcpiTimerLib
-  FILE_GUID                      = E624B98C-845A-4b94-9B50-B20475D552B9
-  MODULE_TYPE                    = DXE_DRIVER
+  BASE_NAME                      = StandaloneMmAcpiTimerLib
+  FILE_GUID                      = C771858D-AF09-4D1A-B2F3-C7F081C3F076
+  MODULE_TYPE                    = MM_STANDALONE
   VERSION_STRING                 = 1.0
-  LIBRARY_CLASS                  = TimerLib|DXE_CORE DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SMM_DRIVER UEFI_APPLICATION UEFI_DRIVER SMM_CORE
-  CONSTRUCTOR                    = DxeAcpiTimerLibConstructor
-  MODULE_UNI_FILE                = DxeAcpiTimerLib.uni
+  PI_SPECIFICATION_VERSION       = 0x00010032
+  LIBRARY_CLASS                  = TimerLib|MM_CORE_STANDALONE MM_STANDALONE
+  CONSTRUCTOR                    = StandaloneMmAcpiTimerLibConstructor

 [Sources]
   AcpiTimerLib.c
-  DxeAcpiTimerLib.c
+  StandaloneMmAcpiTimerLib.c
+  DxeStandaloneMmAcpiTimerLib.c
+  DxeStandaloneMmAcpiTimerLib.h

 [Packages]
   MdePkg/MdePkg.dec
diff --git a/PcAtChipsetPkg/PcAtChipsetPkg.dsc b/PcAtChipsetPkg/PcAtChipsetPkg.dsc
index b61b7d1f528e..3d1fb816f54f 100644
--- a/PcAtChipsetPkg/PcAtChipsetPkg.dsc
+++ b/PcAtChipsetPkg/PcAtChipsetPkg.dsc
@@ -53,6 +53,7 @@ [Components]
   PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
   PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
   PcAtChipsetPkg/Library/AcpiTimerLib/PeiAcpiTimerLib.inf
+  PcAtChipsetPkg/Library/AcpiTimerLib/StandaloneMmAcpiTimerLib.inf
   PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntimeDxe.inf

 [BuildOptions]
--
2.30.0.windows.1