mem: Move the Rank construction logic to the Rank constructor

This change was made so Rank objects have their name assigned
when they are instantiated. Therefore, they can initialize their
member objects with their name and it is less likely to change during
runtime.

(NOTE: I would recommend hiding the fields which would cause the name to
change behind getters. Since modification of `Rank.rank` during runtime
will cause the `name()` to change.)

Change-Id: Id51c3553b40e489792c57950e18b8ce927e43173
Signed-off-by: Sean Wilson <spwilson2@wisc.edu>
Reviewed-on: https://gem5-review.googlesource.com/3742
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

src/mem/dram_ctrl.cc

@@ -104,32 +104,8 @@ DRAMCtrl::DRAMCtrl(const DRAMCtrlParams* p) :
              "must be a power of two\n", burstSize);
 
     for (int i = 0; i < ranksPerChannel; i++) {
-        Rank* rank = new Rank(*this, p);
+        Rank* rank = new Rank(*this, p, i);
         ranks.push_back(rank);
-
-        rank->actTicks.resize(activationLimit, 0);
-        rank->banks.resize(banksPerRank);
-        rank->rank = i;
-
-        for (int b = 0; b < banksPerRank; b++) {
-            rank->banks[b].bank = b;
-            // GDDR addressing of banks to BG is linear.
-            // Here we assume that all DRAM generations address bank groups as
-            // follows:
-            if (bankGroupArch) {
-                // Simply assign lower bits to bank group in order to
-                // rotate across bank groups as banks are incremented
-                // e.g. with 4 banks per bank group and 16 banks total:
-                //    banks 0,4,8,12  are in bank group 0
-                //    banks 1,5,9,13  are in bank group 1
-                //    banks 2,6,10,14 are in bank group 2
-                //    banks 3,7,11,15 are in bank group 3
-                rank->banks[b].bankgr = b % bankGroupsPerRank;
-            } else {
-                // No bank groups; simply assign to bank number
-                rank->banks[b].bankgr = b;
-            }
-        }
     }
 
     // perform a basic check of the write thresholds
@@ -1626,16 +1602,37 @@ DRAMCtrl::minBankPrep(const deque<DRAMPacket*>& queue,
     return make_pair(bank_mask, hidden_bank_prep);
 }
 
-DRAMCtrl::Rank::Rank(DRAMCtrl& _memory, const DRAMCtrlParams* _p)
+DRAMCtrl::Rank::Rank(DRAMCtrl& _memory, const DRAMCtrlParams* _p, int rank)
     : EventManager(&_memory), memory(_memory),
       pwrStateTrans(PWR_IDLE), pwrStatePostRefresh(PWR_IDLE),
       pwrStateTick(0), refreshDueAt(0), pwrState(PWR_IDLE),
-      refreshState(REF_IDLE), inLowPowerState(false), rank(0),
+      refreshState(REF_IDLE), inLowPowerState(false), rank(rank),
       readEntries(0), writeEntries(0), outstandingEvents(0),
-      wakeUpAllowedAt(0), power(_p, false), numBanksActive(0),
+      wakeUpAllowedAt(0), power(_p, false), banks(_p->banks_per_rank),
+      numBanksActive(0), actTicks(_p->activation_limit, 0),
       writeDoneEvent(*this), activateEvent(*this), prechargeEvent(*this),
       refreshEvent(*this), powerEvent(*this), wakeUpEvent(*this)
-{ }
+{
+    for (int b = 0; b < _p->banks_per_rank; b++) {
+        banks[b].bank = b;
+        // GDDR addressing of banks to BG is linear.
+        // Here we assume that all DRAM generations address bank groups as
+        // follows:
+        if (_p->bank_groups_per_rank > 0) {
+            // Simply assign lower bits to bank group in order to
+            // rotate across bank groups as banks are incremented
+            // e.g. with 4 banks per bank group and 16 banks total:
+            //    banks 0,4,8,12  are in bank group 0
+            //    banks 1,5,9,13  are in bank group 1
+            //    banks 2,6,10,14 are in bank group 2
+            //    banks 3,7,11,15 are in bank group 3
+            banks[b].bankgr = b % _p->bank_groups_per_rank;
+        } else {
+            // No bank groups; simply assign to bank number
+            banks[b].bankgr = b;
+        }
+    }
+}
 
 void
 DRAMCtrl::Rank::startup(Tick ref_tick)

src/mem/dram_ctrl.hh

@@ -451,7 +451,7 @@ class DRAMCtrl : public AbstractMemory
         /** List to keep track of activate ticks */
         std::deque<Tick> actTicks;
 
-        Rank(DRAMCtrl& _memory, const DRAMCtrlParams* _p);
+        Rank(DRAMCtrl& _memory, const DRAMCtrlParams* _p, int rank);
 
         const std::string name() const
         {