MdePkg: Add BaseRiscVSbiLib Library for RISC-V

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4076

This library is required to make SBI ecalls from the S-mode EDK2.
This is mostly copied from
edk2-platforms/Silicon/RISC-V/ProcessorPkg/Library/RiscVEdk2SbiLib

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Abner Chang <abner.chang@amd.com>
Reviewed-by: Andrei Warkentin <andrei.warkentin@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>

MdePkg/Include/Library/BaseRiscVSbiLib.h

@@ -0,0 +1,154 @@
+/** @file
+  Library to call the RISC-V SBI ecalls
+
+  Copyright (c) 2021-2022, Hewlett Packard Development LP. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Glossary:
+    - Hart - Hardware Thread, similar to a CPU core
+
+  Currently, EDK2 needs to call SBI only to set the time and to do system reset.
+
+**/
+
+#ifndef RISCV_SBI_LIB_H_
+#define RISCV_SBI_LIB_H_
+
+#include <Uefi.h>
+
+/* SBI Extension IDs */
+#define SBI_EXT_TIME  0x54494D45
+#define SBI_EXT_SRST  0x53525354
+
+/* SBI function IDs for TIME extension*/
+#define SBI_EXT_TIME_SET_TIMER  0x0
+
+/* SBI function IDs for SRST extension */
+#define SBI_EXT_SRST_RESET  0x0
+
+#define SBI_SRST_RESET_TYPE_SHUTDOWN     0x0
+#define SBI_SRST_RESET_TYPE_COLD_REBOOT  0x1
+#define SBI_SRST_RESET_TYPE_WARM_REBOOT  0x2
+
+#define SBI_SRST_RESET_REASON_NONE     0x0
+#define SBI_SRST_RESET_REASON_SYSFAIL  0x1
+
+/* SBI return error codes */
+#define SBI_SUCCESS                0
+#define SBI_ERR_FAILED             -1
+#define SBI_ERR_NOT_SUPPORTED      -2
+#define SBI_ERR_INVALID_PARAM      -3
+#define SBI_ERR_DENIED             -4
+#define SBI_ERR_INVALID_ADDRESS    -5
+#define SBI_ERR_ALREADY_AVAILABLE  -6
+#define SBI_ERR_ALREADY_STARTED    -7
+#define SBI_ERR_ALREADY_STOPPED    -8
+
+#define SBI_LAST_ERR  SBI_ERR_ALREADY_STOPPED
+
+typedef struct {
+  UINT64    BootHartId;
+  VOID      *PeiServiceTable;    // PEI Service table
+  VOID      *PrePiHobList;       // Pre PI Hob List
+  UINT64    FlattenedDeviceTree; // Pointer to Flattened Device tree
+} EFI_RISCV_FIRMWARE_CONTEXT;
+
+//
+// EDK2 OpenSBI firmware extension return status.
+//
+typedef struct {
+  UINTN    Error; ///< SBI status code
+  UINTN    Value; ///< Value returned
+} SBI_RET;
+
+VOID
+EFIAPI
+SbiSetTimer (
+  IN  UINT64  Time
+  );
+
+EFI_STATUS
+EFIAPI
+SbiSystemReset (
+  IN  UINTN  ResetType,
+  IN  UINTN  ResetReason
+  );
+
+/**
+  Get firmware context of the calling hart.
+
+  @param[out] FirmwareContext      The firmware context pointer.
+**/
+VOID
+EFIAPI
+GetFirmwareContext (
+  OUT EFI_RISCV_FIRMWARE_CONTEXT  **FirmwareContext
+  );
+
+/**
+  Set firmware context of the calling hart.
+
+  @param[in] FirmwareContext       The firmware context pointer.
+**/
+VOID
+EFIAPI
+SetFirmwareContext (
+  IN EFI_RISCV_FIRMWARE_CONTEXT  *FirmwareContext
+  );
+
+/**
+  Get pointer to OpenSBI Firmware Context
+
+  Get the pointer of firmware context.
+
+  @param    FirmwareContextPtr   Pointer to retrieve pointer to the
+                                 Firmware Context.
+**/
+VOID
+EFIAPI
+GetFirmwareContextPointer (
+  IN OUT EFI_RISCV_FIRMWARE_CONTEXT  **FirmwareContextPtr
+  );
+
+/**
+  Set pointer to OpenSBI Firmware Context
+
+  Set the pointer of firmware context.
+
+  @param    FirmwareContextPtr   Pointer to Firmware Context.
+**/
+VOID
+EFIAPI
+SetFirmwareContextPointer (
+  IN EFI_RISCV_FIRMWARE_CONTEXT  *FirmwareContextPtr
+  );
+
+/**
+  Make ECALL in assembly
+
+  Switch to M-mode
+
+  @param[in,out]   Arg0
+  @param[in,out]   Arg1
+  @param[in]       Arg2
+  @param[in]       Arg3
+  @param[in]       Arg4
+  @param[in]       Arg5
+  @param[in]       FID
+  @param[in]       EXT
+**/
+VOID
+EFIAPI
+RiscVSbiEcall (
+  IN OUT UINTN  *Arg0,
+  IN OUT UINTN  *Arg1,
+  IN UINTN      Arg2,
+  IN UINTN      Arg3,
+  IN UINTN      Arg4,
+  IN UINTN      Arg5,
+  IN UINTN      Fid,
+  IN UINTN      Ext
+  );
+
+#endif