[RFC PATCH edk2-platforms] Silicon/SynQuacer: add special ResetSystemLib that implements warm reboot

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

This is a clone of the generic PSCI/SMC based ResetSystemLib from ArmPkg,
with an implementation of EnterS3WithImmediateWake () added that simply
disables interrupts, disables the MMU and jumps back to the PEI entry
point when called at boot time. This is sufficiently close to an
architected warm reboot to support capsules that persist across reset,
but is otherwise a bit of a hack.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 Silicon/Socionext/SynQuacer/Library/SynQuacerResetSystemLib/SynQuacerResetSystemLib.c   | 132 ++++++++++++++++++++
 Silicon/Socionext/SynQuacer/Library/SynQuacerResetSystemLib/SynQuacerResetSystemLib.inf |  41 ++++++
 2 files changed, 173 insertions(+)

diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerResetSystemLib/SynQuacerResetSystemLib.c b/Silicon/Socionext/SynQuacer/Library/SynQuacerResetSystemLib/SynQuacerResetSystemLib.c
new file mode 100644
index 000000000000..a4c0c18abd76
--- /dev/null
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerResetSystemLib/SynQuacerResetSystemLib.c
@@ -0,0 +1,132 @@
+/** @file
+  ResetSystemLib implementation for SynQuacer using PSCI calls
+
+  Copyright (c) 2018, 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/ArmMmuLib.h>
+#include <Library/ArmSmcLib.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/ResetSystemLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeLib.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
+  )
+{
+  VOID (*Reset)(VOID);
+
+  if (!EfiAtRuntime ()) {
+    //
+    // At boot time, we are the only core running, so we can implement the
+    // immediate wake (which is used by capsule update) by disabling the MMU
+    // and interrupts, and jumping to the PEI entry point.
+    //
+    Reset = (VOID *)(UINTN)FixedPcdGet64 (PcdFvBaseAddress);
+
+    gBS->RaiseTPL (TPL_HIGH_LEVEL);
+    ArmDisableMmu ();
+    Reset ();
+  }
+  ResetWarm ();
+}
+
+/**
+  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/Silicon/Socionext/SynQuacer/Library/SynQuacerResetSystemLib/SynQuacerResetSystemLib.inf b/Silicon/Socionext/SynQuacer/Library/SynQuacerResetSystemLib/SynQuacerResetSystemLib.inf
new file mode 100644
index 000000000000..0952f6a8f108
--- /dev/null
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerResetSystemLib/SynQuacerResetSystemLib.inf
@@ -0,0 +1,41 @@
+#/** @file
+#  ResetSystemLib implementation for SynQuacer using PSCI calls
+#
+#  Copyright (c) 2018, 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                    = 0x0001001A
+  BASE_NAME                      = SynQuacerResetSystemLib
+  FILE_GUID                      = 6dd8d2f7-08b2-439b-99dd-28247ecd831c
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ResetSystemLib|DXE_RUNTIME_DRIVER
+
+[Sources]
+  SynQuacerResetSystemLib.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  ArmMmuLib
+  ArmSmcLib
+  BaseLib
+  DebugLib
+  UefiBootServicesTableLib
+  UefiRuntimeLib
+
+[FixedPcd]
+  gArmTokenSpaceGuid.PcdFvBaseAddress
-- 
2.17.0