FIRDATA: isolation issues due to SCOM errors from 0x50040018

The first change is to reset the SBE FIFO after SCOM failures on
slave processors. This ensures the FIFO is realigned for subsequent
SCOMs.

The second change is to ignore chiplet offline SCOM errors from
0x50040018 on master processors. These are expected if a core is
asleep at the time of the checkstop. The data returned from the
SCOM will still show active attentions from chiplets that are online.

This commit does not fix chiplet offline SCOM errors from 0x50040018
on slave processors. That will come later in another commit.

Change-Id: Ie60329efed169c9f4afa94154fd86fe466384609
CQ: SW404945
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/48666
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Prachi Gupta <pragupta@us.ibm.com>
Reviewed-by: William G. Hoffa <wghoffa@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: William A. Bryan <wilbryan@us.ibm.com>
Reviewed-by: Brian J. Stegmiller <bjs@us.ibm.com>
Reviewed-by: Martha Broyles <mbroyles@us.ibm.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/src/occ_gpe0/firdata/scom_util.c b/src/occ_gpe0/firdata/scom_util.c
index 3f14acb..ed806cb 100644
--- a/src/occ_gpe0/firdata/scom_util.c
+++ b/src/occ_gpe0/firdata/scom_util.c
@@ -361,11 +361,21 @@ int32_t SCOM_getScom( SCOM_Trgt_t i_trgt, uint32_t i_addr, uint64_t * o_val )
         //Use SBE FIFO if it's a slave proc
         if(!chip_targ.isMaster)
         {
-            return getFifoScom(&chip_targ, trans_addr, o_val);
+            rc = getFifoScom(&chip_targ, trans_addr, o_val);
         }
         else
         {
             rc = getscom_abs(trans_addr, o_val);
+
+            // Add exception for chiplet offline errors on the UNIT_CS or
+            // HOST_ATTN broadcast registers. The value returned will still be
+            // valid. Even though one or more of the chiplets may have been
+            // offline.
+            if ( 2 == rc &&
+                 (0x50040018 == i_addr || 0x50040009 == i_addr) )
+            {
+                rc = SUCCESS;
+            }
         }
     }