ArmPkg: Introduce ResetSystemLib implementation based on ArmMonitorLib

The ARM SMCCC specification stipulates that the conduit for ARM monitor
calls can be determined by taking the conduit for PSCI calls. The
converse is also true, and so we can implement ResetSystemLib for PSCI
using ArmMonitorLib to choose between SMC and HVC instructions.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

ArmPkg/ArmPkg.dsc

@@ -109,6 +109,7 @@
 [Components.common]
   ArmPkg/Library/ArmCacheMaintenanceLib/ArmCacheMaintenanceLib.inf
   ArmPkg/Library/ArmDisassemblerLib/ArmDisassemblerLib.inf
+  ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.inf
   ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
   ArmPkg/Library/DebugAgentSymbolsBaseLib/DebugAgentSymbolsBaseLib.inf
   ArmPkg/Library/DebugPeCoffExtraActionLib/DebugPeCoffExtraActionLib.inf

ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.c

@@ -0,0 +1,176 @@
+/** @file
+  Support ResetSystem Runtime call using PSCI calls
+
+  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+  Copyright (c) 2013, ARM Ltd. All rights reserved.<BR>
+  Copyright (c) 2014, Linaro Ltd. All rights reserved.<BR>
+  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2024, Google Llc. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiDxe.h>
+
+#include <IndustryStandard/ArmStdSmc.h>
+
+#include <Library/ArmMonitorLib.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/ResetSystemLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+/**
+  Library constructor. This function does nothing, but this library may depend
+  on other libraries that do have a non-trivial constructor, which the
+  BaseToools fail to account for if a library has no constructor at all.
+ **/
+RETURN_STATUS
+EFIAPI
+ArmPsciResetSystemLibConstructor (
+  VOID
+  )
+{
+  return EFI_SUCCESS;
+}
+
+/**
+  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
+  )
+{
+  ARM_MONITOR_ARGS  Args;
+
+  // Send a PSCI 0.2 SYSTEM_RESET command
+  Args.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_RESET;
+
+  ArmMonitorCall (&Args);
+}
+
+/**
+  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
+  )
+{
+  ARM_MONITOR_ARGS  Args;
+
+  Args.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_RESET2_AARCH64;
+
+  // Is SYSTEM_RESET2 supported?
+  ArmMonitorCall (&Args);
+  if (Args.Arg0 == ARM_SMC_PSCI_RET_SUCCESS) {
+    // Send PSCI SYSTEM_RESET2 command
+    Args.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_RESET2_AARCH64;
+
+    ArmMonitorCall (&Args);
+  } else {
+    // Map a warm reset into a cold reset
+    DEBUG ((
+      DEBUG_INFO,
+      "Warm reboot not supported by platform, issuing cold reboot\n"
+      ));
+    ResetCold ();
+  }
+}
+
+/**
+  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
+  )
+{
+  ARM_MONITOR_ARGS  Args;
+
+  // Send a PSCI 0.2 SYSTEM_RESET command
+  Args.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_OFF;
+
+  ArmMonitorCall (&Args);
+}
+
+/**
+  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
+  )
+{
+  // Map the platform specific reset as reboot
+  ResetCold ();
+}
+
+/**
+  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;
+  }
+}

ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.inf

@@ -0,0 +1,32 @@
+## @file
+#  Reset System lib using PSCI hypervisor or secure monitor calls
+#
+#  Copyright (c) 2008, Apple Inc. All rights reserved.<BR>
+#  Copyright (c) 2014, Linaro Ltd. All rights reserved.<BR>
+#  Copyright (c) 2024, Google Llc. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 1.29
+  BASE_NAME                      = ArmPsciResetSystemLib
+  FILE_GUID                      = 31db596f-cc80-47fd-849f-e6be5e9f7560
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ResetSystemLib
+  CONSTRUCTOR                    = ArmPsciResetSystemLibConstructor
+
+[Sources]
+  ArmPsciResetSystemLib.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  ArmMonitorLib
+  BaseLib
+  DebugLib