[PATCH 3/4] ArmVirtPkg/PlatformPeiLib: implement Reset2 PPI based on PSCI

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

Extend the existing DT traversal routine in PlatformPeiLib with
discovery of the PSCI method, and expose an implementation of the
Reset2 PPI based on the method found.

This satisfies a dependency of Tcg2Pei, which needs to reset the
platform in some cases. Since there are no other uses for system
reset in PEI on ArmVirtQemu, simply expose the PPI directly rather
than using the generic ResetSystemPei and the associated plumbing.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf |   3 +
 ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c   | 123 ++++++++++++++++++++
 2 files changed, 126 insertions(+)

diff --git a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
index c41ee22c9767..72ed2413a768 100644
--- a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
+++ b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
@@ -28,6 +28,8 @@ [Packages]
   SecurityPkg/SecurityPkg.dec
 
 [LibraryClasses]
+  ArmSmcLib
+  ArmHvcLib
   DebugLib
   HobLib
   FdtLib
@@ -44,6 +46,7 @@ [Pcd]
   gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress         ## SOMETIMES_PRODUCES
 
 [Ppis]
+  gEfiPeiReset2PpiGuid                                    ## SOMETIMES_PRODUCES
   gOvmfTpmDiscoveredPpiGuid                               ## SOMETIMES_PRODUCES
 
 [Guids]
diff --git a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
index 249e45c04624..7af351eda003 100644
--- a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
+++ b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
@@ -9,6 +9,8 @@
 
 #include <PiPei.h>
 
+#include <Library/ArmHvcLib.h>
+#include <Library/ArmSmcLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/DebugLib.h>
 #include <Library/HobLib.h>
@@ -16,15 +18,113 @@
 #include <Library/PeiServicesLib.h>
 #include <libfdt.h>
 
+#include <IndustryStandard/ArmStdSmc.h>
+
 #include <Guid/EarlyPL011BaseAddress.h>
 #include <Guid/FdtHob.h>
 
+#include <Ppi/Reset2.h>
+
 STATIC CONST EFI_PEI_PPI_DESCRIPTOR mTpm2DiscoveredPpi = {
   EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
   &gOvmfTpmDiscoveredPpiGuid,
   NULL
 };
 
+/**
+  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.
+**/
+STATIC
+VOID
+EFIAPI
+ResetSystemHvc (
+  IN EFI_RESET_TYPE               ResetType,
+  IN EFI_STATUS                   ResetStatus,
+  IN UINTN                        DataSize,
+  IN VOID                         *ResetData OPTIONAL
+  )
+{
+  ARM_HVC_ARGS  ArmHvcArgs;
+
+  switch (ResetType) {
+  case EfiResetWarm:
+  case EfiResetCold:
+  case EfiResetPlatformSpecific:
+    // Send a PSCI 0.2 SYSTEM_RESET command
+    ArmHvcArgs.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_RESET;
+    break;
+
+  case EfiResetShutdown:
+    // Send a PSCI 0.2 SYSTEM_OFF command
+    ArmHvcArgs.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_OFF;
+    break;
+
+  default:
+    ASSERT (FALSE);
+    return;
+  }
+  ArmCallHvc (&ArmHvcArgs);
+}
+
+STATIC
+VOID
+EFIAPI
+ResetSystemSmc (
+  IN EFI_RESET_TYPE               ResetType,
+  IN EFI_STATUS                   ResetStatus,
+  IN UINTN                        DataSize,
+  IN VOID                         *ResetData OPTIONAL
+  )
+{
+  ARM_SMC_ARGS  ArmSmcArgs;
+
+  switch (ResetType) {
+  case EfiResetWarm:
+  case EfiResetCold:
+  case EfiResetPlatformSpecific:
+    // Send a PSCI 0.2 SYSTEM_RESET command
+    ArmSmcArgs.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_RESET;
+    break;
+
+  case EfiResetShutdown:
+    // Send a PSCI 0.2 SYSTEM_OFF command
+    ArmSmcArgs.Arg0 = ARM_SMC_ID_PSCI_SYSTEM_OFF;
+    break;
+
+  default:
+    ASSERT (FALSE);
+    return;
+  }
+  ArmCallSmc (&ArmSmcArgs);
+}
+
+STATIC CONST EFI_PEI_RESET2_PPI mPpiReset[] = {
+  { ResetSystemHvc },
+  { ResetSystemSmc },
+};
+
+STATIC CONST EFI_PEI_PPI_DESCRIPTOR mPlatformHvcResetPpi = {
+  EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
+  &gEfiPeiReset2PpiGuid,
+  (EFI_PEI_RESET2_PPI *)&mPpiReset[0]
+};
+
+STATIC CONST EFI_PEI_PPI_DESCRIPTOR mPlatformSmcResetPpi = {
+  EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
+  &gEfiPeiReset2PpiGuid,
+  (EFI_PEI_RESET2_PPI *)&mPpiReset[1]
+};
+
 EFI_STATUS
 EFIAPI
 PlatformPeim (
@@ -47,6 +147,7 @@ PlatformPeim (
   INT32              StatusLen;
   CONST UINT64       *RegProp;
   CONST UINT32       *RangesProp;
+  CONST VOID         *MethodProp;
   UINT64             UartBase;
   UINT64             TpmBase;
   EFI_STATUS         Status;
@@ -155,6 +256,28 @@ PlatformPeim (
         Status = PeiServicesInstallPpi (&mTpm2DiscoveredPpi);
         ASSERT_EFI_ERROR (Status);
         break;
+      } else if (AsciiStrCmp (CompItem, "arm,psci-0.2") == 0) {
+        MethodProp = fdt_getprop (Base, Node, "method", &Len);
+        if (MethodProp == NULL) {
+          DEBUG ((DEBUG_ERROR, "%a: Missing PSCI method property\n",
+            __FUNCTION__));
+          break;
+        }
+
+        if (AsciiStrnCmp (MethodProp, "hvc", 3) == 0) {
+          Status = PeiServicesInstallPpi (&mPlatformHvcResetPpi);
+          ASSERT_EFI_ERROR (Status);
+        } else if (AsciiStrnCmp (MethodProp, "smc", 3) == 0) {
+          Status = PeiServicesInstallPpi (&mPlatformSmcResetPpi);
+          ASSERT_EFI_ERROR (Status);
+        } else {
+          DEBUG ((DEBUG_ERROR, "%a: Unknown PSCI method \"%a\"\n", __FUNCTION__,
+            MethodProp));
+          break;
+        }
+        DEBUG ((DEBUG_INFO, "%a: Detected PSCI method \"%a\"\n", __FUNCTION__,
+          MethodProp));
+        break;
       }
     }
   }
-- 
2.20.1