[PATCH v2 3/5] ArmVirtPkg/PlatformPeiLib: discover the TPM base address from the DT

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

Introduce a boolean PCD that tells us whether TPM support is enabled
in the build, and if it is, record the TPM base address in the existing
routine that traverses the device tree in the platform PEIM.

If a TPM is found, install the gOvmfTpmDiscoveredPpiGuid signalling PPI
that will unlock the dispatch of OvmfPkg's Tcg2ConfigPei. If TPM2
support is enabled in the build but no TPM2 device is found, install the
gPeiTpmInitializationDonePpiGuid PPI, which is normally installed by
Tcg2ConfigPei if no TPM2 is found, but in our case Tcg2ConfigPei will
never run so let's do it here instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmVirtPkg/ArmVirt.dsc.inc                           |   6 ++
 ArmVirtPkg/ArmVirtPkg.dec                            |   6 ++
 ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c   | 101 ++++++++++++++++++--
 ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf |  19 +++-
 4 files changed, 118 insertions(+), 14 deletions(-)

diff --git a/ArmVirtPkg/ArmVirt.dsc.inc b/ArmVirtPkg/ArmVirt.dsc.inc
index 10037c938eb8..abb253fdf76a 100644
--- a/ArmVirtPkg/ArmVirt.dsc.inc
+++ b/ArmVirtPkg/ArmVirt.dsc.inc
@@ -366,6 +366,12 @@ [PcdsFixedAtBuild.common]
   #
   gEfiMdeModulePkgTokenSpaceGuid.PcdDxeNxMemoryProtectionPolicy|0xC000000000007FD1
 
+[PcdsPatchableInModule]
+  # we need a default resolution for this PCD that supports PcdSet64(),
+  # even though any actual calls will be compiled out on builds that have
+  # gArmVirtTokenSpaceGuid.PcdTpm2SupportEnabled == FALSE
+  gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress|0x0
+
 [Components.common]
   #
   # Ramdisk support
diff --git a/ArmVirtPkg/ArmVirtPkg.dec b/ArmVirtPkg/ArmVirtPkg.dec
index a019cc269d10..08ddd68a863e 100644
--- a/ArmVirtPkg/ArmVirtPkg.dec
+++ b/ArmVirtPkg/ArmVirtPkg.dec
@@ -36,6 +36,12 @@ [Guids.common]
 [Protocols]
   gFdtClientProtocolGuid = { 0xE11FACA0, 0x4710, 0x4C8E, { 0xA7, 0xA2, 0x01, 0xBA, 0xA2, 0x59, 0x1B, 0x4C } }
 
+[PcdsFeatureFlag]
+  #
+  # Feature Flag PCD that defines whether TPM2 support is enabled
+  #
+  gArmVirtTokenSpaceGuid.PcdTpm2SupportEnabled|FALSE|BOOLEAN|0x00000004
+
 [PcdsFixedAtBuild, PcdsPatchableInModule]
   #
   # This is the physical address where the device tree is expected to be stored
diff --git a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
index 0a1469550db0..8b5b3dd5dc1c 100644
--- a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
+++ b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
@@ -1,7 +1,7 @@
 /** @file
 *
 *  Copyright (c) 2011-2014, ARM Limited. All rights reserved.
-*  Copyright (c) 2014, Linaro Limited. All rights reserved.
+*  Copyright (c) 2014-2020, Linaro Limited. All rights reserved.
 *
 *  SPDX-License-Identifier: BSD-2-Clause-Patent
 *
@@ -13,11 +13,24 @@
 #include <Library/DebugLib.h>
 #include <Library/HobLib.h>
 #include <Library/PcdLib.h>
+#include <Library/PeiServicesLib.h>
 #include <libfdt.h>
 
 #include <Guid/EarlyPL011BaseAddress.h>
 #include <Guid/FdtHob.h>
 
+STATIC CONST EFI_PEI_PPI_DESCRIPTOR mTpm2DiscoveredPpi = {
+  EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
+  &gOvmfTpmDiscoveredPpiGuid,
+  NULL
+};
+
+STATIC CONST EFI_PEI_PPI_DESCRIPTOR mTpm2InitializationDonePpi = {
+  EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
+  &gPeiTpmInitializationDonePpiGuid,
+  NULL
+};
+
 EFI_STATUS
 EFIAPI
 PlatformPeim (
@@ -31,14 +44,18 @@ PlatformPeim (
   UINT64             *FdtHobData;
   UINT64             *UartHobData;
   INT32              Node, Prev;
+  INT32              Parent, Depth;
   CONST CHAR8        *Compatible;
   CONST CHAR8        *CompItem;
   CONST CHAR8        *NodeStatus;
   INT32              Len;
+  INT32              RangesLen;
   INT32              StatusLen;
   CONST UINT64       *RegProp;
+  CONST UINT32       *RangesProp;
   UINT64             UartBase;
-
+  UINT64             TpmBase;
+  EFI_STATUS         Status;
 
   Base = (VOID*)(UINTN)PcdGet64 (PcdDeviceTreeInitialBaseAddress);
   ASSERT (Base != NULL);
@@ -58,18 +75,18 @@ PlatformPeim (
   ASSERT (UartHobData != NULL);
   *UartHobData = 0;
 
-  //
-  // Look for a UART node
-  //
-  for (Prev = 0;; Prev = Node) {
-    Node = fdt_next_node (Base, Prev, NULL);
+  TpmBase = 0;
+
+  for (Prev = Depth = 0;; Prev = Node) {
+    Node = fdt_next_node (Base, Prev, &Depth);
     if (Node < 0) {
       break;
     }
 
-    //
-    // Check for UART node
-    //
+    if (Depth == 1) {
+      Parent = Node;
+    }
+
     Compatible = fdt_getprop (Base, Node, "compatible", &Len);
 
     //
@@ -93,10 +110,74 @@ PlatformPeim (
 
         *UartHobData = UartBase;
         break;
+      } else if (FeaturePcdGet (PcdTpm2SupportEnabled) &&
+                 AsciiStrCmp (CompItem, "tcg,tpm-tis-mmio") == 0) {
+
+        RegProp = fdt_getprop (Base, Node, "reg", &Len);
+        ASSERT (Len == 8 || Len == 16);
+        if (Len == 8) {
+          TpmBase = fdt32_to_cpu (RegProp[0]);
+        } else if (Len == 16) {
+          TpmBase = fdt64_to_cpu (ReadUnaligned64 ((UINT64 *)RegProp));
+        }
+
+        if (Depth > 1) {
+          //
+          // QEMU/mach-virt may put the TPM on the platform bus, in which case
+          // we have to take its 'ranges' property into account to translate the
+          // MMIO address. This consists of a <child base, parent base, size>
+          // tuple, where the child base and the size use the same number of
+          // cells as the 'reg' property above, and the parent base uses 2 cells
+          //
+          RangesProp = fdt_getprop (Base, Parent, "ranges", &RangesLen);
+          ASSERT (RangesProp != NULL);
+
+          //
+          // a plain 'ranges' attribute without a value implies a 1:1 mapping
+          //
+          if (RangesLen != 0) {
+            //
+            // assume a single translated range with 2 cells for the parent base
+            //
+            if (RangesLen != Len + 2 * sizeof (UINT32)) {
+              DEBUG ((DEBUG_WARN,
+                "%a: 'ranges' property has unexpected size %d\n",
+                __FUNCTION__, RangesLen));
+              break;
+            }
+
+            if (Len == 8) {
+              TpmBase -= fdt32_to_cpu (RangesProp[0]);
+            } else {
+              TpmBase -= fdt64_to_cpu (ReadUnaligned64 ((UINT64 *)RangesProp));
+            }
+
+            //
+            // advance RangesProp to the parent bus address
+            //
+            RangesProp = (UINT32 *)((UINT8 *)RangesProp + Len / 2);
+            TpmBase += fdt64_to_cpu (ReadUnaligned64 ((UINT64 *)RangesProp));
+          }
+        }
+        break;
       }
     }
   }
 
+  if (FeaturePcdGet (PcdTpm2SupportEnabled)) {
+    if (TpmBase != 0) {
+      DEBUG ((DEBUG_INFO, "%a: TPM @ 0x%lx\n", __FUNCTION__, TpmBase));
+
+      Status = (EFI_STATUS)PcdSet64S (PcdTpmBaseAddress, TpmBase);
+      ASSERT_EFI_ERROR (Status);
+
+      Status = PeiServicesInstallPpi (&mTpm2DiscoveredPpi);
+    } else {
+      Status = PeiServicesInstallPpi (&mTpm2InitializationDonePpi);
+    }
+    ASSERT_EFI_ERROR (Status);
+  }
+
   BuildFvHob (PcdGet64 (PcdFvBaseAddress), PcdGet32 (PcdFvSize));
 
   return EFI_SUCCESS;
diff --git a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
index 5428040f121d..3f97ef080520 100644
--- a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
+++ b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
@@ -1,7 +1,7 @@
 #/** @file
 #
 #  Copyright (c) 2011-2015, ARM Limited. All rights reserved.
-#  Copyright (c) 2014, Linaro Limited. All rights reserved.
+#  Copyright (c) 2014-2020, Linaro Limited. All rights reserved.
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -11,7 +11,7 @@ [Defines]
   INF_VERSION                    = 0x00010005
   BASE_NAME                      = PlatformPeiLib
   FILE_GUID                      = 59C11815-F8DA-4F49-B4FB-EC1E41ED1F06
-  MODULE_TYPE                    = SEC
+  MODULE_TYPE                    = BASE
   VERSION_STRING                 = 1.0
   LIBRARY_CLASS                  = PlatformPeiLib
 
@@ -21,15 +21,21 @@ [Sources]
 [Packages]
   ArmPkg/ArmPkg.dec
   ArmVirtPkg/ArmVirtPkg.dec
-  MdePkg/MdePkg.dec
-  MdeModulePkg/MdeModulePkg.dec
   EmbeddedPkg/EmbeddedPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+  SecurityPkg/SecurityPkg.dec
+
+[FeaturePcd]
+  gArmVirtTokenSpaceGuid.PcdTpm2SupportEnabled
 
 [LibraryClasses]
   DebugLib
   HobLib
   FdtLib
   PcdLib
+  PeiServicesLib
 
 [FixedPcd]
   gArmTokenSpaceGuid.PcdFvSize
@@ -38,6 +44,11 @@ [FixedPcd]
 [Pcd]
   gArmTokenSpaceGuid.PcdFvBaseAddress
   gArmVirtTokenSpaceGuid.PcdDeviceTreeInitialBaseAddress
+  gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress         ## SOMETIMES_PRODUCES
+
+[Ppis]
+  gOvmfTpmDiscoveredPpiGuid                               ## SOMETIMES_PRODUCES
+  gPeiTpmInitializationDonePpiGuid                        ## SOMETIMES_PRODUCES
 
 [Guids]
   gEarlyPL011BaseAddressGuid
-- 
2.17.1