[PATCH 2/4] 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.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmVirtPkg/ArmVirtPkg.dec                            |  5 ++
 ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf | 12 ++-
 ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c   | 82 +++++++++++++++++---
 3 files changed, 87 insertions(+), 12 deletions(-)

diff --git a/ArmVirtPkg/ArmVirtPkg.dec b/ArmVirtPkg/ArmVirtPkg.dec
index a019cc269d10..ed5114887489 100644
--- a/ArmVirtPkg/ArmVirtPkg.dec
+++ b/ArmVirtPkg/ArmVirtPkg.dec
@@ -58,6 +58,11 @@ [PcdsFixedAtBuild, PcdsPatchableInModule]
   #
   gArmVirtTokenSpaceGuid.PcdTerminalTypeGuidBuffer|{0x65, 0x60, 0xA6, 0xDF, 0x19, 0xB4, 0xD3, 0x11, 0x9A, 0x2D, 0x00, 0x90, 0x27, 0x3F, 0xC1, 0x4D}|VOID*|0x00000007
 
+  #
+  # Boolean PCD that defines whether TPM2 support is enabled
+  #
+  gArmVirtTokenSpaceGuid.PcdTpm2SupportEnabled|FALSE|BOOLEAN|0x00000004
+
 [PcdsDynamic]
   #
   # Whether to force disable ACPI, regardless of the fw_cfg settings
diff --git a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
index 46db117ac28e..c41ee22c9767 100644
--- a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
+++ b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.inf
@@ -21,22 +21,30 @@ [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
 
 [LibraryClasses]
   DebugLib
   HobLib
   FdtLib
+  PeiServicesLib
 
 [FixedPcd]
   gArmTokenSpaceGuid.PcdFvSize
   gArmVirtTokenSpaceGuid.PcdDeviceTreeAllocationPadding
+  gArmVirtTokenSpaceGuid.PcdTpm2SupportEnabled
 
 [Pcd]
   gArmTokenSpaceGuid.PcdFvBaseAddress
   gArmVirtTokenSpaceGuid.PcdDeviceTreeInitialBaseAddress
+  gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress         ## SOMETIMES_PRODUCES
+
+[Ppis]
+  gOvmfTpmDiscoveredPpiGuid                               ## SOMETIMES_PRODUCES
 
 [Guids]
   gEarlyPL011BaseAddressGuid
diff --git a/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c b/ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c
index 0a1469550db0..249e45c04624 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 +13,18 @@
 #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
+};
+
 EFI_STATUS
 EFIAPI
 PlatformPeim (
@@ -31,13 +38,18 @@ 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);
@@ -58,18 +70,16 @@ PlatformPeim (
   ASSERT (UartHobData != NULL);
   *UartHobData = 0;
 
-  //
-  // Look for a UART node
-  //
-  for (Prev = 0;; Prev = Node) {
-    Node = fdt_next_node (Base, Prev, NULL);
+  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);
 
     //
@@ -89,10 +99,62 @@ PlatformPeim (
 
         UartBase = fdt64_to_cpu (ReadUnaligned64 (RegProp));
 
-        DEBUG ((EFI_D_INFO, "%a: PL011 UART @ 0x%lx\n", __FUNCTION__, UartBase));
+        DEBUG ((DEBUG_INFO, "%a: PL011 UART @ 0x%lx\n", __FUNCTION__, UartBase));
 
         *UartHobData = UartBase;
         break;
+      } else if (FixedPcdGetBool (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));
+          }
+        }
+
+        DEBUG ((DEBUG_INFO, "%a: TPM @ 0x%lx\n", __FUNCTION__, TpmBase));
+
+        Status = PcdSet64S (PcdTpmBaseAddress, TpmBase);
+        ASSERT_RETURN_ERROR (Status);
+
+        Status = PeiServicesInstallPpi (&mTpm2DiscoveredPpi);
+        ASSERT_EFI_ERROR (Status);
+        break;
       }
     }
   }
-- 
2.20.1