PK DEC timer interrupts too close together

Change-Id: If62e99e8977fda7211df4e56b78f0d64d2d13217
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/37820
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: PPE CI <ppe-ci+hostboot@us.ibm.com>
Reviewed-by: RAHUL BATRA <rbatra@us.ibm.com>
Reviewed-by: YUE DU <daviddu@us.ibm.com>
Reviewed-by: Gregory S. Still <stillgs@us.ibm.com>

2 files changed, 18 insertions, 9 deletions

diff --git a/import/chips/p9/procedures/ppe/pk/kernel/pk_api.h b/import/chips/p9/procedures/ppe/pk/kernel/pk_api.h
index 48405df7..a841cb8b 100644
--- a/import/chips/p9/procedures/ppe/pk/kernel/pk_api.h
+++ b/import/chips/p9/procedures/ppe/pk/kernel/pk_api.h
@@ -234,6 +234,10 @@
 
 #define PK_TIMEBASE_MAX ((PkTimebase)-1)
 
+/// The minimum count the DEC counter can have so as to not overrun PK
+///  with DEC interrupts.
+#define PK_DEC_MIN  32
+
 /// A special value that specifies that the timebase will not be reset during
 /// pk_init().
 
@@ -955,7 +959,10 @@ extern PkDeque _pk_bh_queue;
 static inline void
 pk_bh_schedule(PkBottomHalf* bottom_half)
 {
-    pk_deque_push_back(&_pk_bh_queue, (PkDeque*)bottom_half);
+    if(!pk_deque_is_queued((PkDeque*)bottom_half))
+    {
+        pk_deque_push_back(&_pk_bh_queue, (PkDeque*)bottom_half);
+    }
 }
 
 #define PK_BH_INIT(_handler, _arg) \
diff --git a/import/chips/p9/procedures/ppe/pk/ppe42/ppe42_core.c b/import/chips/p9/procedures/ppe/pk/ppe42/ppe42_core.c
index fb37c652..e7355257 100644
--- a/import/chips/p9/procedures/ppe/pk/ppe42/ppe42_core.c
+++ b/import/chips/p9/procedures/ppe/pk/ppe42/ppe42_core.c
@@ -114,17 +114,15 @@ __pk_schedule_hardware_timeout(PkTimebase timeout)
     PkTimebase       diff;
     uint32_t         new_dec;
 
+    now = pk_timebase_get();
+    //update the 64bit accumulator with the current
+    ppe42_64bit_timebase =  now;
+
     if (timeout != PK_TIMEBASE_MAX)
     {
-
-        now = pk_timebase_get();
-
-        //update our 64bit accumulator with the current snapshot
-        ppe42_64bit_timebase = now;
-
         if (timeout <= now)
         {
-            new_dec = 1;
+            new_dec = PK_DEC_MIN;
         }
         else
         {
@@ -137,11 +135,15 @@ __pk_schedule_hardware_timeout(PkTimebase timeout)
             else
             {
                 new_dec = diff;
+
+                if(new_dec < PK_DEC_MIN)
+                {
+                    new_dec = PK_DEC_MIN;
+                }
             }
         }
 
         mtspr(SPRN_DEC, new_dec);
-
     }
 }