Secure Boot: Dynamically set TPM I2C master path in MRW parser

Historically the TPM target as described in the MRW passes directly through to
the Hostboot targeting model without modification (other than filtering out
unwanted attributes).  This approach does not work in multi-TPM or multi-node
systems since the TPM object's I2C master path gets cloned within and across
nodes.  Instead, for multi-node systems, the MRW parser must now walk the I2C
bus connections between each TPM and the chip driving it, and dynamically
compute/set the TPM's I2C master path.  This behavior only activates for
multi-TPM systems due to limitations in other workbooks, as in these cases, the
pre-existing behavior sufficies.

Change-Id: I5845760a390841d083dc0bbe633bc19a90ab23e6
RTC: 184515
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/55240
CI-Ready: Nicholas E. Bofferding <bofferdn@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: Santosh S. Puranik <santosh.puranik@in.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: ILYA SMIRNOV <ismirno@us.ibm.com>
Reviewed-by: Marshall J. Wilks <mjwilks@us.ibm.com>
Reviewed-by: Michael Baiocchi <mbaiocch@us.ibm.com>
Reviewed-by: William G. Hoffa <wghoffa@us.ibm.com>

1 files changed, 101 insertions, 1 deletions

diff --git a/src/usr/targeting/common/processMrw.pl b/src/usr/targeting/common/processMrw.pl
index f152cda67..9d9494a5f 100755
--- a/src/usr/targeting/common/processMrw.pl
+++ b/src/usr/targeting/common/processMrw.pl
@@ -212,9 +212,49 @@ sub addObusCfgToGpuSensors
     }
 }
 
+#  @brief Returns whether system has multiple possible TPMs or not
+#
+#  @par Detailed Description:
+#      Returns whether system has multiple possible TPMs or not.
+#      The MRW parser activates more complicated I2C master detection logic when
+#      a system blueprint defines more than one TPM, in order to avoid having to
+#      fix other non-compliant workbooks.  If every workbook is determined to
+#      model the TPM and its I2C connection properly, this special case can be
+#      removed.
+#
+#  @param[in] $targetsRef Reference to array of targets in the system
+#  @retval 0 System does not have multiple possible TPMs
+#  @retval 1 System has multiple possible TPMs
+#
+#  @TODO RTC: 189374 Remove API when all platforms' MRW supports dynamically
+#      determining the processor driving it.
+
+sub isMultiTpmSystem
+{
+    my $targetsRef = shift;
+
+    my $tpms=0;
+    foreach my $target (@$targetsRef)
+    {
+        my $type = $targetObj->getType($target);
+        if($type eq "TPM")
+        {
+            ++$tpms;
+            if($tpms >1)
+            {
+                last;
+            }
+        }
+    }
+
+    return ($tpms > 1) ? 1 : 0;
+}
+
 #--------------------------------------------------
 ## loop through all targets and do stuff
-foreach my $target (sort keys %{ $targetObj->getAllTargets() })
+my @targets = sort keys %{ $targetObj->getAllTargets() };
+my $isMultiTpmSys = isMultiTpmSystem(\@targets);
+foreach my $target (@targets)
 {
     my $type = $targetObj->getType($target);
     if ($type eq "SYS")
@@ -312,6 +352,12 @@ foreach my $target (sort keys %{ $targetObj->getAllTargets() })
         $targetObj->deleteAttribute($target,"SLOT_NAME");
         $targetObj->deleteAttribute($target,"VENDOR_ID");
     }
+    # @TODO RTC: 189374 Remove multiple TPMs filter when all platforms' MRW
+    # supports dynamically determining the processor driving it.
+    elsif (($type eq "TPM") && $isMultiTpmSys)
+    {
+        processTpm($targetObj, $target);
+    }
 
     processIpmiSensors($targetObj,$target);
 }
@@ -696,6 +742,60 @@ sub parseBitwise
         $targetObj->setAttribute($target,$attribute,$mask);
     }
 }
+
+#  @brief Processes a TPM target
+#
+#  @par Detailed Description:
+#      Processes a TPM target; notably determines the TPM's I2C master chip and
+#      updates the associated field in the TPM_INFO attribute, especially useful
+#      on multi-node or multi-TPM systems.
+#
+#  @param[in] $targetObj Object model reference
+#  @param[in] $target    Handle of the target to process
+
+sub processTpm
+{
+    my $targetObj = shift;
+    my $target    = shift;
+
+    # Get any connection involving TPM target's child I2C slave targets
+    my $i2cBuses=$targetObj->findDestConnections($target,"I2C","");
+    if ($i2cBuses ne "")
+    {
+        foreach my $i2cBus (@{$i2cBuses->{CONN}})
+        {
+            # On the I2C master side of the connection, ascend one level to the
+            # parent chip
+            my $i2cMasterParentTarget=$i2cBus->{SOURCE_PARENT};
+            my $i2cMasterParentTargetType =
+                $targetObj->getType($i2cMasterParentTarget);
+
+            # Hostboot code assumes CEC TPMs are only connected to processors.
+            # Unless that assumption changes, this sanity check is required to
+            # catch modeling errors.
+            if($i2cMasterParentTargetType ne "PROC")
+            {
+                die   "Model integrity error; CEC TPM I2C connections must "
+                    . "originate at a PROC target, not a "
+                    . "$i2cMasterParentTargetType target.\n";
+            }
+
+            # Get its physical path
+            my $i2cMasterParentTargetPath = $targetObj->getAttribute(
+                $i2cMasterParentTarget,"PHYS_PATH");
+
+            # Set the TPM's I2C master path accordingly
+            $targetObj->setAttributeField(
+                $target, "TPM_INFO","i2cMasterPath",
+                $i2cMasterParentTargetPath);
+
+            # All TPM I2C buses must be driven from the same I2C master, so only
+            # process the first one
+            last;
+        }
+    }
+}
+
 #--------------------------------------------------
 ## Processor
 ##