MdePkg: Add a new library named PeiServicesTablePointerLibKs0

Adding PeiServicesTablePointerLibKs0 for LoongArch64, which provides
setting and getting the PEI service table pointer through the CSR KS0
register.

The idea of this library is derived from
ArmPkg/Library/PeiServicesTablePointerLib/

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4584

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Chao Li <lichao@loongson.cn>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

MdePkg/Include/Library/PeiServicesTablePointerLib.h

@@ -52,10 +52,11 @@ SetPeiServicesTablePointer (
   immediately preceding the Interrupt Descriptor Table (IDT) in memory.
   For X64 CPUs, the PEI Services Table pointer is stored in the 8 bytes
   immediately preceding the Interrupt Descriptor Table (IDT) in memory.
-  For Itanium and ARM CPUs, a the PEI Services Table Pointer is stored in
-  a dedicated CPU register.  This means that there is no memory storage
-  associated with storing the PEI Services Table pointer, so no additional
-  migration actions are required for Itanium or ARM CPUs.
+  For Itanium, ARM and LoongArch CPUs, a the PEI Services Table Pointer
+  is stored in a dedicated CPU register.  This means that there is no
+  memory storage associated with storing the PEI Services Table pointer,
+  so no additional migration actions are required for Itanium, ARM and
+  LoongArch CPUs.
 
 **/
 VOID

MdePkg/Library/PeiServicesTablePointerLibKs0/PeiServicesTablePointer.c

@@ -0,0 +1,87 @@
+/** @file
+  PEI Services Table Pointer Library For Reigseter Mechanism.
+
+  This library is used for PEIM which does executed from flash device directly but
+  executed in memory.
+
+  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2011 Hewlett-Packard Corporation. All rights reserved.<BR>
+  Copyright (c) 2024 Loongson Technology Corporation Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiPei.h>
+#include <Library/DebugLib.h>
+#include <Library/PeiServicesTablePointerLib.h>
+#include <Register/LoongArch64/Csr.h>
+
+/**
+  Caches a pointer PEI Services Table.
+
+  Caches the pointer to the PEI Services Table specified by PeiServicesTablePointer
+  in a platform specific manner.
+
+  If PeiServicesTablePointer is NULL, then ASSERT().
+
+  @param    PeiServicesTablePointer   The address of PeiServices pointer.
+**/
+VOID
+EFIAPI
+SetPeiServicesTablePointer (
+  IN CONST EFI_PEI_SERVICES  **PeiServicesTablePointer
+  )
+{
+  ASSERT (PeiServicesTablePointer != NULL);
+  CsrWrite (LOONGARCH_CSR_KS0, (UINTN)PeiServicesTablePointer);
+}
+
+/**
+  Retrieves the cached value of the PEI Services Table pointer.
+
+  Returns the cached value of the PEI Services Table pointer in a CPU specific manner
+  as specified in the CPU binding section of the Platform Initialization Pre-EFI
+  Initialization Core Interface Specification.
+
+  If the cached PEI Services Table pointer is NULL, then ASSERT().
+
+  @return  The pointer to PeiServices.
+
+**/
+CONST EFI_PEI_SERVICES **
+EFIAPI
+GetPeiServicesTablePointer (
+  VOID
+  )
+{
+  CONST EFI_PEI_SERVICES  **PeiServices;
+
+  PeiServices = (CONST EFI_PEI_SERVICES **)(CsrRead (LOONGARCH_CSR_KS0));
+  ASSERT (PeiServices != NULL);
+  return PeiServices;
+}
+
+/**
+  Perform CPU specific actions required to migrate the PEI Services Table
+  pointer from temporary RAM to permanent RAM.
+
+  For IA32 CPUs, the PEI Services Table pointer is stored in the 4 bytes
+  immediately preceding the Interrupt Descriptor Table (IDT) in memory.
+  For X64 CPUs, the PEI Services Table pointer is stored in the 8 bytes
+  immediately preceding the Interrupt Descriptor Table (IDT) in memory.
+  For Itanium, ARM and LoongArch CPUs, a the PEI Services Table Pointer
+  is stored in a dedicated CPU register.  This means that there is no
+  memory storage associated with storing the PEI Services Table pointer,
+  so no additional migration actions are required for Itanium, ARM and
+  LoongArch CPUs.
+
+**/
+VOID
+EFIAPI
+MigratePeiServicesTablePointer (
+  VOID
+  )
+{
+  return;
+}

MdePkg/Library/PeiServicesTablePointerLibKs0/PeiServicesTablePointerLibKs0.inf

@@ -0,0 +1,37 @@
+## @file
+# Instance of PEI Services Table Pointer Library using register CSR KS0 for the table pointer.
+#
+# PEI Services Table Pointer Library implementation that retrieves a pointer to the
+# PEI Services Table from a CPU register. Applies to modules that execute from
+# read-only memory.
+#
+# Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2011 Hewlett-Packard Corporation. All rights reserved.<BR>
+# Copyright (c) 2024 Loongson Technology Corporation Limited. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+  INF_VERSION                    = 1.29
+  BASE_NAME                      = PeiServicesTablePointerLib
+  MODULE_UNI_FILE                = PeiServicesTablePointerLibKs0.uni
+  FILE_GUID                      = 619950D1-7C5F-EA1B-D6DD-2FF7B0A4A2B7
+  MODULE_TYPE                    = PEIM
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = PeiServicesTablePointerLib|PEIM PEI_CORE SEC
+
+#
+#  VALID_ARCHITECTURES           = LOONGARCH64
+#
+
+[Sources]
+  PeiServicesTablePointer.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  DebugLib

MdePkg/Library/PeiServicesTablePointerLibKs0/PeiServicesTablePointerLibKs0.uni

@@ -0,0 +1,20 @@
+// /** @file
+// Instance of PEI Services Table Pointer Library using register CSR KS0 for the table pointer.
+//
+// PEI Services Table Pointer Library implementation that retrieves a pointer to the
+// PEI Services Table from a CPU register. Applies to modules that execute from
+// read-only memory.
+//
+// Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved.<BR>
+// Copyright (c) 2011 Hewlett-Packard Corporation. All rights reserved.<BR>
+// Copyright (c) 2024 Loongson Technology Corporation Limited. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT             #language en-US "Instance of PEI Services Table Pointer Library using CPU register for the table pointer"
+
+#string STR_MODULE_DESCRIPTION          #language en-US "The PEI Services Table Pointer Library implementation that retrieves a pointer to the PEI Services Table from a CPU register. Applies to modules that execute from read-only memory."
+

MdePkg/MdePkg.dsc

@@ -200,4 +200,7 @@
   MdePkg/Library/BaseSerialPortLibRiscVSbiLib/BaseSerialPortLibRiscVSbiLib.inf
   MdePkg/Library/BaseSerialPortLibRiscVSbiLib/BaseSerialPortLibRiscVSbiLibRam.inf
 
+[Components.LOONGARCH64]
+  MdePkg/Library/PeiServicesTablePointerLibKs0/PeiServicesTablePointerLibKs0.inf
+
 [BuildOptions]