Reviewed-by: Chao Li <lichao@loongson.cn>

Thanks,
Chao
--------

On 11月 11 2022, at 5:12 下午, xianglai li <lixianglai@loongson.cn> wrote:
> Use a register to save PeiServicesTable pointer,
>
> This lib Provides PeiServicesTable pointer saving
> and retrieval services.
>
>
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4054
>
>
> Cc: Bibo Mao <maobibo@loongson.cn>
> Cc: Chao Li <lichao@loongson.cn>
> Cc: Leif Lindholm <quic_llindhol@quicinc.com>
> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Signed-off-by: xianglai li <lixianglai@loongson.cn>
> ---
> .../PeiServicesTablePointer.c | 79 +++++++++++++++++++
> .../PeiServicesTablePointer.h | 39 +++++++++
> .../PeiServicesTablePointerLib.S | 40 ++++++++++
> .../PeiServicesTablePointerLib.inf | 32 ++++++++
> 4 files changed, 190 insertions(+)
> create mode 100644 Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c
> create mode 100644 Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.h
> create mode 100644 Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.S
> create mode 100644 Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.inf
>
>
> diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c b/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c
> new file mode 100644
> index 0000000000..204def3bde
> --- /dev/null
> +++ b/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.c
> @@ -0,0 +1,79 @@
> +/** @file
> + PEI Services Table Pointer Library.
> +
> + Copyright (c) 2022 Loongson Technology Corporation Limited. All rights reserved.<BR>
> +
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <PiPei.h>
> +#include <Library/PeiServicesTablePointerLib.h>
> +#include <Library/DebugLib.h>
> +#include "Library/Cpu.h"
> +#include "PeiServicesTablePointer.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
> + )
> +{
> + LoongarchWriteqKs0 ((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
> + )
> +{
> + UINTN val;
> +
> + LoongarchReadqKs0 (&val);
> +
> + return (CONST EFI_PEI_SERVICES **)val;
> +}
> +
> +/**
> +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 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.
> +*/
> +VOID
> +EFIAPI
> +MigratePeiServicesTablePointer (
> +VOID
> +)
> +{
> + return;
> +}
> diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.h b/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.h
> new file mode 100644
> index 0000000000..5bcbc810d0
> --- /dev/null
> +++ b/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointer.h
> @@ -0,0 +1,39 @@
> +/** @file
> + PeiServicesTablePointer
> +
> + Copyright (c) 2022 Loongson Technology Corporation Limited. All rights reserved.<BR>
> +
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#ifndef PEISERVICESTABLEPOINTER_H_
> +#define PEISERVICESTABLEPOINTER_H_
> +
> +/**
> + Write Csr KS0 register.
> +
> + @param A0 The value used to write to the KS0 register
> +
> + @retval none
> +**/
> +extern
> +VOID
> +LoongarchWriteqKs0 (
> + IN UINT64 Val
> + );
> +
> +/**
> + Read Csr KS0 register.
> +
> + @param Val Pointer to the variable used to store the KS0 register value
> +
> + @retval none
> +**/
> +extern
> +VOID
> +LoongarchReadqKs0 (
> + IN UINT64 *Val
> + );
> +
> +#endif // PEISERVICESTABLEPOINTER_H_
> diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.S b/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.S
> new file mode 100644
> index 0000000000..7c6170c5d6
> --- /dev/null
> +++ b/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.S
> @@ -0,0 +1,40 @@
> +#------------------------------------------------------------------------------
> +#
> +# Timer Cfg for LoongArch
> +#
> +# Copyright (c) 2022 Loongson Technology Corporation Limited. All rights reserved.<BR>
> +#
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +#------------------------------------------------------------------------------
> +
> +#ifndef __ASSEMBLY__
> +#define __ASSEMBLY__
> +#endif
> +
> +#include "Library/Cpu.h"
> +
> +ASM_GLOBAL ASM_PFX(LoongarchWriteqKs0)
> +ASM_GLOBAL ASM_PFX(LoongarchReadqKs0)
> +
> +#
> +# Write Csr KS0 register.
> +# @param A0 The value used to write to the KS0 register
> +# @retval none
> +#
> +
> +ASM_PFX(LoongarchWriteqKs0):
> + csrwr A0, LOONGARCH_CSR_KS0
> + jirl ZERO, RA,0
> +
> +#
> +# Write Csr KS0 register.
> +# @param A0 Pointer to the variable used to store the KS0 register value
> +# @retval none
> +#
> +
> +ASM_PFX(LoongarchReadqKs0):
> + csrrd T0, LOONGARCH_CSR_KS0
> + stptr.d T0, A0, 0
> + jirl ZERO, RA,0
> + jirl ZERO, RA,0
> diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.inf b/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.inf
> new file mode 100644
> index 0000000000..2ab0d53d4c
> --- /dev/null
> +++ b/Platform/Loongson/LoongArchQemuPkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.inf
> @@ -0,0 +1,32 @@
> +## @file
> +# PEI Services Table Pointer Library.
> +#
> +# Copyright (c) 2022 Loongson Technology Corporation Limited. All rights reserved.<BR>
> +#
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +[Defines]
> + INF_VERSION = 0x00010005
> + BASE_NAME = PeiServicesTablePointerLib
> + FILE_GUID = C3C9C4ED-EB8A-4548-BE1B-ABB0B6F35B1E
> + MODULE_TYPE = PEIM
> + VERSION_STRING = 1.0
> + LIBRARY_CLASS = PeiServicesTablePointerLib|PEIM PEI_CORE SEC
> +
> +#
> +# VALID_ARCHITECTURES = LOONGARCH64
> +#
> +
> +[Sources]
> + PeiServicesTablePointer.c
> + PeiServicesTablePointerLib.S
> +
> +[Packages]
> + Platform/Loongson/LoongArchQemuPkg/Loongson.dec
> + MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> + DebugLib
> +
> +[Pcd]
> --
> 2.31.1