Avoid istep skipping in secure mode

Change-Id: I273c1e1f6720db08eb66366a3c1e88f8b10b5411
RTC: 184523
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/51931
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Shakeeb A. Pasha B K <shakeebbk@in.ibm.com>
Reviewed-by: RAJA DAS <rajadas2@in.ibm.com>
Reviewed-by: Sachin Gupta <sgupta2m@in.ibm.com>

4 files changed, 64 insertions, 9 deletions

diff --git a/src/sbefw/app/power/istep.C b/src/sbefw/app/power/istep.C
index 77445b85..29622d8d 100644
--- a/src/sbefw/app/power/istep.C
+++ b/src/sbefw/app/power/istep.C
@@ -6,6 +6,7 @@
 /* OpenPOWER sbe Project                                                  */
 /*                                                                        */
 /* Contributors Listed Below - COPYRIGHT 2017,2018                        */
+/* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
 /* Licensed under the Apache License, Version 2.0 (the "License");        */
@@ -44,19 +45,18 @@ using namespace fapi2;
 //----------------------------------------------------------------------------
 bool validateIstep (const uint8_t i_major, const uint8_t i_minor)
 {
-    bool valid = true;
+    #define SBE_FUNC "validateIstep "
+    bool valid = false;
     do
     {
         if( 0 == i_minor )
         {
-            valid = false;
             break;
         }
         // istep 2.1 loads image to PIBMEM
         // So SBE control loop can not execute istep 2.1.
         if(( i_major == 2 ) && ( i_minor == 1) )
         {
-            valid = false;
             break;
         }
 
@@ -65,26 +65,66 @@ bool validateIstep (const uint8_t i_major, const uint8_t i_minor)
             if(( i_major == 3 && i_minor > SLAVE_LAST_MINOR_ISTEP ) ||
                ( i_major > 3 ))
             {
-                valid = false;
                 break;
             }
         }
 
+        uint32_t prevMajorNumber =
+                    SbeRegAccess::theSbeRegAccess().getSbeMajorIstepNumber();
+        uint32_t prevMinorNumber =
+                    SbeRegAccess::theSbeRegAccess().getSbeMinorIstepNumber();
+        SBE_INFO(SBE_FUNC"prevMajorNumber:%u prevMinorNumber:%u ",
+                         prevMajorNumber, prevMinorNumber );
+        if( 0 == prevMajorNumber )
+        {
+            prevMajorNumber = 2;
+            prevMinorNumber = 1;
+        }
+
+        uint32_t nextMajorIstep = prevMajorNumber;
+        uint32_t nextMinorIstep = prevMinorNumber + 1;
+
         for(size_t entry = 0; entry < istepTable.len; entry++)
         {
             auto istepTableEntry = &istepTable.istepMajorArr[entry];
+            if( istepTableEntry->istepMajorNum == prevMajorNumber)
+            {
+                if( prevMinorNumber == istepTableEntry->len )
+                {
+                    nextMajorIstep = prevMajorNumber + 1;
+                    nextMinorIstep =  1;
+                }
+            }
             if( i_major == istepTableEntry->istepMajorNum )
             {
                 if( i_minor > istepTableEntry->len )
                 {
-                    valid = false;
+                    break;
+                }
+                // If secuirty is not enabled, no further chacks asre required
+                if( !SBE_GLOBAL->sbeFWSecurityEnabled)
+                {
+                    valid = true;
+                    break;
                 }
+
+                if( ( i_major != nextMajorIstep) ||
+                    ( i_minor != nextMinorIstep) )
+                {
+                    SBE_ERROR("Secuity validation failed for executing istep "
+                           "Skipping istep or MPIPL via istep not allowed "
+                           "in secure mode. nextMajorIstep:%u "
+                           "nextMinorIstep:%u", nextMajorIstep, nextMinorIstep);
+                    break;
+                }
+                valid = true;
                 break;
             }
         }
     } while(0);
 
     return valid;
+    #undef SBE_FUNC
 }
 
 //----------------------------------------------------------------------------
diff --git a/src/sbefw/core/ipl.C b/src/sbefw/core/ipl.C
index 965a198b..d331af59 100644
--- a/src/sbefw/core/ipl.C
+++ b/src/sbefw/core/ipl.C
@@ -6,6 +6,7 @@
 /* OpenPOWER sbe Project                                                  */
 /*                                                                        */
 /* Contributors Listed Below - COPYRIGHT 2017,2018                        */
+/* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
 /* Licensed under the Apache License, Version 2.0 (the "License");        */
@@ -66,14 +67,16 @@ ReturnCode sbeExecuteIstep (const uint8_t i_major, const uint8_t i_minor)
         }
     }
 
-    (void)SbeRegAccess::theSbeRegAccess().updateSbeStep(i_major, i_minor);
-
     if(rc != FAPI2_RC_SUCCESS)
     {
         SBE_ERROR( SBE_FUNC" FAPI RC:0x%08X", rc);
         (void)SbeRegAccess::theSbeRegAccess().stateTransition(
                                                     SBE_DUMP_FAILURE_EVENT);
     }
+    else
+    {
+        (void)SbeRegAccess::theSbeRegAccess().updateSbeStep(i_major, i_minor);
+    } 
 
     return rc;
     #undef SBE_FUNC
diff --git a/src/sbefw/core/sbeglobals.H b/src/sbefw/core/sbeglobals.H
index c26967a6..e182a20b 100644
--- a/src/sbefw/core/sbeglobals.H
+++ b/src/sbefw/core/sbeglobals.H
@@ -5,7 +5,8 @@
 /*                                                                        */
 /* OpenPOWER sbe Project                                                  */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2017                             */
+/* Contributors Listed Below - COPYRIGHT 2017,2018                        */
+/* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
 /* Licensed under the Apache License, Version 2.0 (the "License");        */
diff --git a/src/sbefw/core/sberegaccess.H b/src/sbefw/core/sberegaccess.H
index 420cf795..a51f6e81 100644
--- a/src/sbefw/core/sberegaccess.H
+++ b/src/sbefw/core/sberegaccess.H
@@ -5,7 +5,8 @@
 /*                                                                        */
 /* OpenPOWER sbe Project                                                  */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2016,2017                        */
+/* Contributors Listed Below - COPYRIGHT 2016,2018                        */
+/* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
 /* Licensed under the Apache License, Version 2.0 (the "License");        */
@@ -220,6 +221,16 @@ class SbeRegAccess
         }
 
         /**
+         * @brief Get the SBE minor istep number
+         *
+         * @return SBE current minor istep number
+         *
+         */
+        uint8_t getSbeMinorIstepNumber() const
+        {
+            return iv_minorStep;
+        }
+        /**
          * @brief Update the SBE State as per the transition event
          *
          * @param [in] i_event Transition Event