[PATCH] ArmPkg: implement ResetSystemLib using PSCI 0.2 calls

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

This adds an implementation of the ResetSystemLib library class as
defined in MdeModulePkg. It is used as the platform glue by the generic
ResetSystemRuntimeDxe which lives in the same package.

This implementation is intended to replace the EfiResetSystemLib based
implementation that is deprecated now that we have decided that there is
no longer a reason to keep a different ResetSystem() implementation
under EmbeddedPkg.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.c   | 115 ++++++++++++++++++++
 ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.inf |  35 ++++++
 2 files changed, 150 insertions(+)

diff --git a/ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.c b/ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.c
new file mode 100644
index 000000000000..d6d26bce5009
--- /dev/null
+++ b/ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.c
@@ -0,0 +1,115 @@
+/** @file
+  ResetSystemLib implementation using PSCI calls
+
+  Copyright (c) 2017, Linaro Ltd. All rights reserved.<BR>
+
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution. The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <PiDxe.h>
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/ResetSystemLib.h>
+#include <Library/ArmSmcLib.h>
+
+#include <IndustryStandard/ArmStdSmc.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
+  )
+{
+  ARM_SMC_ARGS ArmSmcArgs;
+
+  // Send a PSCI 0.2 SYSTEM_RESET command
+  ArmSmcArgs.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_RESET;
+  ArmCallSmc (&ArmSmcArgs);
+}
+
+/**
+  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
+  )
+{
+  // Map a warm reset into a cold reset
+  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_SMC_ARGS ArmSmcArgs;
+
+  // Send a PSCI 0.2 SYSTEM_OFF command
+  ArmSmcArgs.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_OFF;
+  ArmCallSmc (&ArmSmcArgs);
+}
+
+/**
+  This function causes the system to enter S3 and then wake up immediately.
+
+  If this function returns, it means that the system does not support S3 feature.
+**/
+VOID
+EFIAPI
+EnterS3WithImmediateWake (
+  VOID
+  )
+{
+  // Not implemented
+}
+
+/**
+  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 ();
+}
diff --git a/ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.inf b/ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.inf
new file mode 100644
index 000000000000..3e66f75a3498
--- /dev/null
+++ b/ArmPkg/Library/ArmSmcPsciResetSystemLib/ArmSmcPsciResetSystemLib.inf
@@ -0,0 +1,35 @@
+#/** @file
+#  ResetSystemLib implementation using PSCI calls
+#
+#  Copyright (c) 2017, Linaro Ltd. All rights reserved.<BR>
+#
+#  This program and the accompanying materials
+#  are licensed and made available under the terms and conditions of the BSD License
+#  which accompanies this distribution. The full text of the license may be found at
+#  http://opensource.org/licenses/bsd-license.php
+#
+#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 0x00010019
+  BASE_NAME                      = ArmPsciResetSystemLib
+  FILE_GUID                      = 18B12C83-7718-4D83-ADA4-87F2FE698DD4
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ResetSystemLib
+
+[Sources]
+  ArmSmcPsciResetSystemLib.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  ArmSmcLib
+  BaseLib
+  DebugLib
-- 
2.9.3