MEM: Enable multiple distributed generalized memories

This patch removes the assumption on having on single instance of
PhysicalMemory, and enables a distributed memory where the individual
memories in the system are each responsible for a single contiguous
address range.

All memories inherit from an AbstractMemory that encompasses the basic
behaviuor of a random access memory, and provides untimed access
methods. What was previously called PhysicalMemory is now
SimpleMemory, and a subclass of AbstractMemory. All future types of
memory controllers should inherit from AbstractMemory.

To enable e.g. the atomic CPU and RubyPort to access the now
distributed memory, the system has a wrapper class, called
PhysicalMemory that is aware of all the memories in the system and
their associated address ranges. This class thus acts as an
infinitely-fast bus and performs address decoding for these "shortcut"
accesses. Each memory can specify that it should not be part of the
global address map (used e.g. by the functional memories by some
testers). Moreover, each memory can be configured to be reported to
the OS configuration table, useful for populating ATAG structures, and
any potential ACPI tables.

Checkpointing support currently assumes that all memories have the
same size and organisation when creating and resuming from the
checkpoint. A future patch will enable a more flexible
re-organisation.

--HG--
rename : src/mem/PhysicalMemory.py => src/mem/AbstractMemory.py
rename : src/mem/PhysicalMemory.py => src/mem/SimpleMemory.py
rename : src/mem/physical.cc => src/mem/abstract_mem.cc
rename : src/mem/physical.hh => src/mem/abstract_mem.hh
rename : src/mem/physical.cc => src/mem/simple_mem.cc
rename : src/mem/physical.hh => src/mem/simple_mem.hh

2 files changed, 6 insertions, 13 deletions

diff --git a/src/cpu/simple/atomic.cc b/src/cpu/simple/atomic.cc
index 41bcf9268..90f4fa579 100644
--- a/src/cpu/simple/atomic.cc
+++ b/src/cpu/simple/atomic.cc
@@ -95,10 +95,6 @@ AtomicSimpleCPU::init()
         }
     }
 
-    if (fastmem) {
-        AddrRangeList pmAddrList = system->physmem->getAddrRanges();
-        physMemAddr = *pmAddrList.begin();
-    }
     // Atomic doesn't do MT right now, so contextId == threadId
     ifetch_req.setThreadContext(_cpuId, 0); // Add thread ID if we add MT
     data_read_req.setThreadContext(_cpuId, 0); // Add thread ID here too
@@ -283,8 +279,8 @@ AtomicSimpleCPU::readMem(Addr addr, uint8_t * data,
             if (req->isMmappedIpr())
                 dcache_latency += TheISA::handleIprRead(thread->getTC(), &pkt);
             else {
-                if (fastmem && pkt.getAddr() == physMemAddr)
-                    dcache_latency += system->physmem->doAtomicAccess(&pkt);
+                if (fastmem && system->isMemAddr(pkt.getAddr()))
+                    system->getPhysMem().access(&pkt);
                 else
                     dcache_latency += dcachePort.sendAtomic(&pkt);
             }
@@ -385,8 +381,8 @@ AtomicSimpleCPU::writeMem(uint8_t *data, unsigned size,
                     dcache_latency +=
                         TheISA::handleIprWrite(thread->getTC(), &pkt);
                 } else {
-                    if (fastmem && pkt.getAddr() == physMemAddr)
-                        dcache_latency += system->physmem->doAtomicAccess(&pkt);
+                    if (fastmem && system->isMemAddr(pkt.getAddr()))
+                        system->getPhysMem().access(&pkt);
                     else
                         dcache_latency += dcachePort.sendAtomic(&pkt);
                 }
@@ -481,9 +477,8 @@ AtomicSimpleCPU::tick()
                                                Packet::Broadcast);
                     ifetch_pkt.dataStatic(&inst);
 
-                    if (fastmem && ifetch_pkt.getAddr() == physMemAddr)
-                        icache_latency =
-                            system->physmem->doAtomicAccess(&ifetch_pkt);
+                    if (fastmem && system->isMemAddr(ifetch_pkt.getAddr()))
+                        system->getPhysMem().access(&ifetch_pkt);
                     else
                         icache_latency = icachePort.sendAtomic(&ifetch_pkt);
 
diff --git a/src/cpu/simple/atomic.hh b/src/cpu/simple/atomic.hh
index c0112836a..3e6238f7d 100644
--- a/src/cpu/simple/atomic.hh
+++ b/src/cpu/simple/atomic.hh
@@ -110,8 +110,6 @@ class AtomicSimpleCPU : public BaseSimpleCPU
     bool dcache_access;
     Tick dcache_latency;
 
-    Range<Addr> physMemAddr;
-
   protected:
 
     /** Return a reference to the data port. */