Re: [edk2-devel] [PATCH v2 4/5] ArmVirtPkg: implement ArmVirtPsciResetSystemPeiLib

["Laszlo Ersek" <lersek@redhat.com>]

On 02/25/20 11:44, Ard Biesheuvel wrote:
> Implement a ArmVirtPkg specific version of the PSCI ResetSystemLib that
> is usable in the PEI phase, as the existing one relies on the FDT client
> protocol, making it unsuitable.
> 
> Note that accessing the device tree passed by QEMU via its initial base
> address is guaranteed to be safe at any time during the PEI phase, so we
> can defer discovery of the PSCI method until the time the reset library
> is actually invoked (which is rarely)
> 
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.c   | 232 ++++++++++++++++++++
>  ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.inf |  39 ++++
>  2 files changed, 271 insertions(+)
> 
> diff --git a/ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.c b/ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.c
> new file mode 100644
> index 000000000000..394a04e3c384
> --- /dev/null
> +++ b/ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.c
> @@ -0,0 +1,232 @@
> +/** @file
> +  Reset System lib using PSCI hypervisor or secure monitor calls
> +
> +  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
> +  Copyright (c) 2013, ARM Ltd. All rights reserved.<BR>
> +  Copyright (c) 2014-2020, Linaro Ltd. All rights reserved.<BR>
> +  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <PiPei.h>
> +
> +#include <libfdt.h>
> +#include <Library/ArmHvcLib.h>
> +#include <Library/ArmSmcLib.h>
> +#include <Library/BaseLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/HobLib.h>
> +#include <Library/ResetSystemLib.h>
> +
> +#include <IndustryStandard/ArmStdSmc.h>
> +
> +typedef enum {
> +  PsciMethodUnknown,
> +  PsciMethodSmc,
> +  PsciMethodHvc,
> +} PSCI_METHOD;
> +
> +STATIC
> +PSCI_METHOD
> +DiscoverPsciMethod (
> +  VOID
> +  )
> +{
> +  VOID                            *DeviceTreeBase;
> +  INT32                           Node, Prev;
> +  INT32                           Len;
> +  CONST CHAR8                     *Compatible;
> +  CONST CHAR8                     *CompatibleItem;
> +  CONST VOID                      *Prop;
> +
> +  DeviceTreeBase = (VOID*)(UINTN)PcdGet64 (PcdDeviceTreeInitialBaseAddress);
> +  ASSERT (fdt_check_header (DeviceTreeBase) == 0);
> +
> +  //
> +  // Enumerate all FDT nodes looking for the PSCI node and capture the method
> +  //
> +  for (Prev = 0;; Prev = Node) {
> +    Node = fdt_next_node (DeviceTreeBase, Prev, NULL);
> +    if (Node < 0) {
> +      break;
> +    }
> +
> +    Compatible = fdt_getprop (DeviceTreeBase, Node, "compatible", &Len);
> +    if (Compatible == NULL) {
> +      continue;
> +    }
> +
> +    //
> +    // Iterate over the NULL-separated items in the compatible string
> +    //
> +    for (CompatibleItem = Compatible; CompatibleItem < Compatible + Len;
> +      CompatibleItem += 1 + AsciiStrLen (CompatibleItem)) {
> +
> +      if (AsciiStrCmp (CompatibleItem, "arm,psci-0.2") != 0) {
> +        continue;
> +      }
> +
> +      Prop = fdt_getprop (DeviceTreeBase, Node, "method", NULL);
> +      if (!Prop) {
> +        DEBUG ((DEBUG_ERROR, "%a: Missing PSCI method property\n",
> +          __FUNCTION__));
> +        return PsciMethodUnknown;
> +      }
> +
> +      if (AsciiStrnCmp (Prop, "hvc", 3) == 0) {
> +        return PsciMethodHvc;
> +      } else if (AsciiStrnCmp (Prop, "smc", 3) == 0) {
> +        return PsciMethodSmc;
> +      } else {
> +        DEBUG ((DEBUG_ERROR, "%a: Unknown PSCI method \"%a\"\n", __FUNCTION__,
> +          Prop));
> +        return PsciMethodUnknown;
> +      }
> +    }
> +  }
> +  return PsciMethodUnknown;
> +}
> +
> +STATIC
> +VOID
> +PerformPsciAction (
> +  IN  UINTN     Arg0
> +  )
> +{
> +  ARM_SMC_ARGS ArmSmcArgs;
> +  ARM_HVC_ARGS ArmHvcArgs;
> +
> +  ArmSmcArgs.Arg0 = Arg0;
> +  ArmHvcArgs.Arg0 = Arg0;
> +
> +  switch (DiscoverPsciMethod ()) {
> +  case PsciMethodHvc:
> +    ArmCallHvc (&ArmHvcArgs);
> +    break;
> +
> +  case PsciMethodSmc:
> +    ArmCallSmc (&ArmSmcArgs);
> +    break;
> +
> +  default:
> +    DEBUG ((DEBUG_ERROR, "%a: no PSCI method defined\n", __FUNCTION__));
> +    ASSERT (FALSE);
> +  }
> +}
> +
> +/**
> +  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
> +  )
> +{
> +  // Send a PSCI 0.2 SYSTEM_RESET command
> +  PerformPsciAction (ARM_SMC_ID_PSCI_SYSTEM_RESET);
> +}
> +
> +/**
> +  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
> +  )
> +{
> +  // Send a PSCI 0.2 SYSTEM_OFF command
> +  PerformPsciAction (ARM_SMC_ID_PSCI_SYSTEM_OFF);
> +}
> +
> +/**
> +  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;
> +  }
> +}
> diff --git a/ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.inf b/ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.inf
> new file mode 100644
> index 000000000000..3a65706e8dc6
> --- /dev/null
> +++ b/ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.inf
> @@ -0,0 +1,39 @@
> +#/** @file
> +# Reset System lib using PSCI hypervisor or secure monitor calls
> +#
> +# Copyright (c) 2008, Apple Inc. All rights reserved.<BR>
> +# Copyright (c) 2014-2020, Linaro Ltd. All rights reserved.<BR>
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +#
> +#**/
> +
> +[Defines]
> +  INF_VERSION                    = 1.27
> +  BASE_NAME                      = ArmVirtPsciResetSystemPeiLib
> +  FILE_GUID                      = 551cfb98-c185-41a3-86bf-8cdb7e2a530c
> +  MODULE_TYPE                    = BASE
> +  VERSION_STRING                 = 1.0
> +  LIBRARY_CLASS                  = ResetSystemLib|PEIM
> +
> +[Sources]
> +  ArmVirtPsciResetSystemPeiLib.c
> +
> +[Packages]
> +  ArmPkg/ArmPkg.dec
> +  ArmVirtPkg/ArmVirtPkg.dec
> +  EmbeddedPkg/EmbeddedPkg.dec
> +  MdeModulePkg/MdeModulePkg.dec
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  ArmSmcLib
> +  ArmHvcLib
> +  BaseLib
> +  DebugLib
> +  FdtLib
> +  HobLib
> +
> +[Pcd]
> +  gArmVirtTokenSpaceGuid.PcdDeviceTreeInitialBaseAddress
> 

Acked-by: Laszlo Ersek <lersek@redhat.com>