[edk2-devel] [edk2-platforms PATCH 2/7] LoongArchQemuPkg/LsRealTimeClockLib: remove superfluous instance init steps

["Laszlo Ersek" <lersek@redhat.com>]

RealTimeClockLib instances are consumed by edk2's
EmbeddedPkg/RealTimeClockRuntimeDxe driver. In its entry point function
InitializeRealTimeClock(), the driver:

(1) calls LibRtcInitialize(),

(2) sets the GetTime(), SetTime(), GetWakeupTime() and SetWakeupTime()
    runtime services to its own similarly-named functions -- where those
    functions wrap the corresponding RealTimeClockLib APIs,

(3) installs EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL with a NULL protocol
    interface.

Steps (2) and (3) conform to PI v1.8 sections II-9.7.2.4 through
II-9.7.2.7.

However, this means that LibRtcInitialize() (of any RealTimeClockLib
instance) should not itself (a) set the GetTime(), SetTime(),
GetWakeupTime() and SetWakeupTime() runtime services, nor (b) install
EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL. The runtime service pointers will be
overwritten in step (2) anyway, and step (3) will uselessly install a
second (NULL-interface) EFI_REAL_TIME_CLOCK_ARCH_PROTOCOL instance in the
protocol database. (The protocol only serves to notify the DXE Foundation
about said runtime services being available.)

Clean up LoongArchQemuPkg/LsRealTimeClockLib accordingly.

(Note that the lib instance INF file already does not list
UefiRuntimeServicesTableLib.)

Build-tested only (with "Loongson.dsc").

Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Chao Li <lichao@loongson.cn>
Cc: Xianglai li <lixianglai@loongson.cn>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4565
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---

Notes:
    context:-W

 Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.inf |  3 ---
 Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.c   | 16 ----------------
 2 files changed, 19 deletions(-)

diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.inf b/Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.inf
index 5aa95650f8ba..c5ab1a702167 100644
--- a/Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.inf
+++ b/Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.inf
@@ -40,8 +40,5 @@ [Pcd]
 [Guids]
   gEfiEventVirtualAddressChangeGuid
 
-[Protocols]
-  gEfiRealTimeClockArchProtocolGuid             # PROTOCOL ALWAYS_PRODUCED
-
 [Depex]
   TRUE
diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.c b/Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.c
index eeac011a9400..954589ecb328 100644
--- a/Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.c
+++ b/Platform/Loongson/LoongArchQemuPkg/Library/LsRealTimeClockLib/LsRealTimeClockLib.c
@@ -1,30 +1,28 @@
 /** @file
   Implement EFI RealTimeClock runtime services via RTC Lib.
 
   Copyright (c) 2022, Loongson Limited. All rights reserved.
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
 #include <Uefi.h>
 #include <PiDxe.h>
 
 #include <Guid/EventGroup.h>
 #include <Guid/GlobalVariable.h>
 
 #include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
 #include <Library/DxeServicesTableLib.h>
 #include <Library/IoLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/PcdLib.h>
 #include <Library/RealTimeClockLib.h>
 #include <Library/TimeBaseLib.h>
 #include <Library/UefiBootServicesTableLib.h>
-#include <Library/UefiRuntimeServicesTableLib.h>
 #include <Library/UefiRuntimeLib.h>
-#include <Protocol/RealTimeClock.h>
 #include "LsRealTimeClock.h"
 
 STATIC BOOLEAN                mInitialized = FALSE;
@@ -291,46 +289,32 @@ EFIAPI
 LibRtcInitialize (
   IN EFI_HANDLE                            ImageHandle,
   IN EFI_SYSTEM_TABLE                      *SystemTable
   )
 {
   EFI_STATUS    Status;
-  EFI_HANDLE    Handle;
 
   InitRtc ();
   Status = KvmtoolRtcMapMemory (ImageHandle, (mRtcBase & ~EFI_PAGE_MASK));
   if (EFI_ERROR (Status)) {
     DEBUG ((
       DEBUG_ERROR,
       "Failed to map memory for loongson 7A RTC. Status = %r\n",
       Status
       ));
     return Status;
   }
 
-  // Setup the setters and getters
-  gRT->GetTime       = LibGetTime;
-  gRT->SetTime       = LibSetTime;
-
-  // Install the protocol
-  Handle = NULL;
-  Status = gBS->InstallMultipleProtocolInterfaces (
-                  &Handle,
-                  &gEfiRealTimeClockArchProtocolGuid,  NULL,
-                  NULL
-                 );
-  ASSERT_EFI_ERROR (Status);
-
   //
   // Register for the virtual address change event
   //
   Status = gBS->CreateEventEx (
                   EVT_NOTIFY_SIGNAL,
                   TPL_NOTIFY,
                   VirtualNotifyEvent,
                   NULL,
                   &gEfiEventVirtualAddressChangeGuid,
                   &mRtcVirtualAddrChangeEvent
                   );
   ASSERT_EFI_ERROR (Status);
   return Status;
 }



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