[Skiboot] [PATCH 1/2] SCOM Restore: Handle case of old HB and new STOP API case.

[Akshay Adiga]

From: Prem Shanker Jha <premjha2 at in.ibm.com>

Commit addresses a situation where STOP API is new and HB is
old. It detects the siutation and retains legacy behavior.
This situation can arise if PHYP tries to use SCOM restore
changes of STOP API with older fipsdriver or OPAL does the
same on older HB binaries.
Key_Cronus_Test=PM_REGRESS

Change-Id: Iaaa866169904a47e10c79ae4894d2eedccfafe53
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/62610
Tested-by: Jenkins Server <pfd-jenkins+hostboot at us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot at us.ibm.com>
Tested-by: Cronus HW CI <cronushw-ci+hostboot at us.ibm.com>
Reviewed-by: RANGANATHPRASAD G. BRAHMASAMUDRA <prasadbgr at in.ibm.com>
Reviewed-by: AMIT J. TENDOLKAR <amit.tendolkar at in.ibm.com>
Reviewed-by: Gregory S. Still <stillgs at us.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/62614
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot at us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot at us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot at us.ibm.com>
Reviewed-by: Christian R. Geddes <crgeddes at us.ibm.com>
[build fixes for OPAL : Akshay Adiga]
Signed-off-by: Akshay Adiga <akshay.adiga at linux.vnet.ibm.com>
---
 libpore/p9_stop_api.C | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/libpore/p9_stop_api.C b/libpore/p9_stop_api.C
index 4e6a1f89..03d9ff99 100644
--- a/libpore/p9_stop_api.C
+++ b/libpore/p9_stop_api.C
@@ -32,6 +32,8 @@
 // *HWP Team        :  PM
 // *HWP Level       :  2
 // *HWP Consumed by :  HB:HYP
+
+// *INDENT-OFF*
 #ifdef PPC_HYP
     #include <HvPlicModule.H>
 #endif
@@ -69,6 +71,8 @@ const StopSprReg_t g_sprRegister[] =
 };
 
 const uint32_t MAX_SPR_SUPPORTED =  10;
+const uint32_t LEGACY_CORE_SCOM_SUPPORTED   =   15;
+const uint32_t LEGACY_QUAD_SCOM_SUPPORTED   =   63;
 
 //-----------------------------------------------------------------------------
 
@@ -835,16 +839,24 @@ StopReturnCode_t p9_stop_save_scom( void* const   i_pImage,
             l_maxScomRestoreEntry   =
                 *(uint32_t*)((uint8_t*)i_pImage + CPMR_HOMER_OFFSET + CPMR_MAX_SCOM_REST_PER_CORE_BYTE);
             pScomEntry              =   CORE_ID_SCOM_START(i_pImage, chipletId )
-                                        cacheEntry              =   false;
-	    if( !l_maxScomRestoreEntry )
-	    {
-                l_maxScomRestoreEntry   = 15;
+            cacheEntry              =   false;
+
+            if( !l_maxScomRestoreEntry )
+            {
+                //Old HB and new STOP API case. Retain legacy Number
+                l_maxScomRestoreEntry   =  SWIZZLE_4_BYTE(LEGACY_CORE_SCOM_SUPPORTED);
             }
         }
         else
         {
             l_maxScomRestoreEntry   =
                 *(uint32_t*)((uint8_t*)i_pImage + QPMR_HOMER_OFFSET + QPMR_QUAD_MAX_SCOM_ENTRY_BYTE);
+
+            if( !l_maxScomRestoreEntry )
+            {
+                // Incase of a bad HOMER header initialization, fall back on legacy number.
+                l_maxScomRestoreEntry   =  SWIZZLE_4_BYTE(LEGACY_QUAD_SCOM_SUPPORTED);
+            }
             // chiplet is a cache. let us find start address of cache section
             // associated with given chiplet. A cache section associated with
             // given chiplet is split in to L2, L3 and EQ area.
@@ -895,13 +907,16 @@ StopReturnCode_t p9_stop_save_scom( void* const   i_pImage,
                 break;
         }
 
+
         if(( imageVer > LEGACY_SCOM_RESTORE_VER ) && ( cacheEntry ) )
         {
             //STOP API migrated to newer algorithm for creation of entries
+
             pScomEntry  =   CACHE_SCOM_ADDR(i_pImage,
                                             chipletId,
                                             l_maxScomRestoreEntry )
-                            entryLimit  =   l_maxScomRestoreEntry;
+
+            entryLimit  =   l_maxScomRestoreEntry;
         }
 
         if(( !pScomEntry ) || ( l_rc ) )
-- 
2.17.1