[RFC PATCH 11/17] MdePkg/Library: Add ResetSystemLib library

["Sunil V L" <sunilvl@ventanamicro.com>]

This library implements system reset interfaces like cold reboot,
warm reboot etc. On RISC-V platforms, these are implemented using
SBI calls.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
 .../Library/ResetSystemLib/ResetSystemLib.inf |  35 +++++
 .../ResetSystemLib/RiscV64/ResetSystemLib.c   | 128 ++++++++++++++++++
 2 files changed, 163 insertions(+)
 create mode 100644 MdePkg/Library/ResetSystemLib/ResetSystemLib.inf
 create mode 100644 MdePkg/Library/ResetSystemLib/RiscV64/ResetSystemLib.c

diff --git a/MdePkg/Library/ResetSystemLib/ResetSystemLib.inf b/MdePkg/Library/ResetSystemLib/ResetSystemLib.inf
new file mode 100644
index 0000000000..7c8a7d1142
--- /dev/null
+++ b/MdePkg/Library/ResetSystemLib/ResetSystemLib.inf
@@ -0,0 +1,35 @@
+## @file
+#  Library instance for ResetSystem library class
+#
+#  Copyright (c) 2021, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+#  Copyright (c) 2022, Ventana Micro Systems Inc. All rights reserved.<BR>
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = ResetSystemLib
+  FILE_GUID                      = 425DC96A-BF26-4684-90F9-1B5FF43BE927
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ResetSystemLib
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = RISCV64
+#
+
+[Sources.RISCV64]
+  RiscV64/ResetSystemLib.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  UefiCpuPkg/UefiCpuPkg.dec
+
+[LibraryClasses]
+  DebugLib
+
+[LibraryClasses.RISCV64]
+  RiscVSbiLib
diff --git a/MdePkg/Library/ResetSystemLib/RiscV64/ResetSystemLib.c b/MdePkg/Library/ResetSystemLib/RiscV64/ResetSystemLib.c
new file mode 100644
index 0000000000..c077ef6ac7
--- /dev/null
+++ b/MdePkg/Library/ResetSystemLib/RiscV64/ResetSystemLib.c
@@ -0,0 +1,128 @@
+/** @file
+  Reset System Library functions for RISC-V
+
+  Copyright (c) 2021, Hewlett Packard Development LP. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/ResetSystemLib.h>
+#include <Library/RiscVSbiLib.h>
+
+/**
+  This function causes a system-wide reset (cold reset), in which
+  all circuitry within the system returns to its initial state. This type of reset
+  is asynchronous to system operation and operates without regard to
+  cycle boundaries.
+
+  If this function returns, it means that the system does not support cold reset.
+**/
+VOID
+EFIAPI
+ResetCold (
+  VOID
+  )
+{
+  // Warm Reset via SBI ecall
+  SbiSystemReset (SBI_SRST_RESET_TYPE_COLD_REBOOT, SBI_SRST_RESET_REASON_NONE);
+}
+
+/**
+  This function causes a system-wide initialization (warm reset), in which all processors
+  are set to their initial state. Pending cycles are not corrupted.
+
+  If this function returns, it means that the system does not support warm reset.
+**/
+VOID
+EFIAPI
+ResetWarm (
+  VOID
+  )
+{
+  // Warm Reset via SBI ecall
+  SbiSystemReset (SBI_SRST_RESET_TYPE_WARM_REBOOT, SBI_SRST_RESET_REASON_NONE);
+}
+
+/**
+  This function causes the system to enter a power state equivalent
+  to the ACPI G2/S5 or G3 states.
+
+  If this function returns, it means that the system does not support shutdown reset.
+**/
+VOID
+EFIAPI
+ResetShutdown (
+  VOID
+  )
+{
+  // Shut down via SBI ecall
+  SbiSystemReset (SBI_SRST_RESET_TYPE_SHUTDOWN, SBI_SRST_RESET_REASON_NONE);
+}
+
+/**
+  This function causes a systemwide reset. The exact type of the reset is
+  defined by the EFI_GUID that follows the Null-terminated Unicode string passed
+  into ResetData. If the platform does not recognize the EFI_GUID in ResetData
+  the platform must pick a supported reset type to perform. The platform may
+  optionally log the parameters from any non-normal reset that occurs.
+
+  @param[in]  DataSize   The size, in bytes, of ResetData.
+  @param[in]  ResetData  The data buffer starts with a Null-terminated string,
+                         followed by the EFI_GUID.
+**/
+VOID
+EFIAPI
+ResetPlatformSpecific (
+  IN UINTN  DataSize,
+  IN VOID   *ResetData
+  )
+{
+  //
+  // Can map to OpenSBI vendor or platform specific reset type.
+  //
+  return;
+}
+
+/**
+  The ResetSystem function resets the entire platform.
+
+  @param[in] ResetType      The type of reset to perform.
+  @param[in] ResetStatus    The status code for the reset.
+  @param[in] DataSize       The size, in bytes, of ResetData.
+  @param[in] ResetData      For a ResetType of EfiResetCold, EfiResetWarm, or EfiResetShutdown
+                            the data buffer starts with a Null-terminated string, optionally
+                            followed by additional binary data. The string is a description
+                            that the caller may use to further indicate the reason for the
+                            system reset.
+**/
+VOID
+EFIAPI
+ResetSystem (
+  IN EFI_RESET_TYPE  ResetType,
+  IN EFI_STATUS      ResetStatus,
+  IN UINTN           DataSize,
+  IN VOID            *ResetData OPTIONAL
+  )
+{
+  switch (ResetType) {
+    case EfiResetWarm:
+      ResetWarm ();
+      break;
+
+    case EfiResetCold:
+      ResetCold ();
+      break;
+
+    case EfiResetShutdown:
+      ResetShutdown ();
+      return;
+
+    case EfiResetPlatformSpecific:
+      ResetPlatformSpecific (DataSize, ResetData);
+      return;
+
+    default:
+      return;
+  }
+}
-- 
2.25.1