mem: Add support for a security bit in the memory system

This patch adds the basic building blocks required to support e.g. ARM
TrustZone by discerning secure and non-secure memory accesses.

1 files changed, 26 insertions, 7 deletions

diff --git a/src/mem/cache/prefetch/stride.cc b/src/mem/cache/prefetch/stride.cc
index cb67f50f8..fd8b20fcc 100644
--- a/src/mem/cache/prefetch/stride.cc
+++ b/src/mem/cache/prefetch/stride.cc
@@ -1,4 +1,16 @@
 /*
+ * Copyright (c) 2012-2013 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
  * Copyright (c) 2005 The Regents of The University of Michigan
  * All rights reserved.
  *
@@ -48,6 +60,7 @@ StridePrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
     }
 
     Addr blk_addr = pkt->getAddr() & ~(Addr)(blkSize-1);
+    bool is_secure = pkt->isSecure();
     MasterID master_id = useMasterId ? pkt->req->masterId() : 0;
     Addr pc = pkt->req->getPC();
     assert(master_id < Max_Contexts);
@@ -56,7 +69,8 @@ StridePrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
     /* Scan Table for instAddr Match */
     std::list<StrideEntry*>::iterator iter;
     for (iter = tab.begin(); iter != tab.end(); iter++) {
-        if ((*iter)->instAddr == pc)
+        // Entries have to match on the security state as well
+        if ((*iter)->instAddr == pc && (*iter)->isSecure == is_secure)
             break;
     }
 
@@ -75,11 +89,13 @@ StridePrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
                 (*iter)->confidence = 0;
         }
 
-        DPRINTF(HWPrefetch, "hit: PC %x blk_addr %x stride %d (%s), conf %d\n",
-                pc, blk_addr, new_stride, stride_match ? "match" : "change",
+        DPRINTF(HWPrefetch, "hit: PC %x blk_addr %x (%s) stride %d (%s), "
+                "conf %d\n", pc, blk_addr, is_secure ? "s" : "ns", new_stride,
+                stride_match ? "match" : "change",
                 (*iter)->confidence);
 
         (*iter)->missAddr = blk_addr;
+        (*iter)->isSecure = is_secure;
 
         if ((*iter)->confidence <= 0)
             return;
@@ -91,8 +107,8 @@ StridePrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
                 pfSpanPage += degree - d + 1;
                 return;
             } else {
-                DPRINTF(HWPrefetch, "  queuing prefetch to %x @ %d\n",
-                        new_addr, latency);
+                DPRINTF(HWPrefetch, "  queuing prefetch to %x (%s) @ %d\n",
+                        new_addr, is_secure ? "s" : "ns", latency);
                 addresses.push_back(new_addr);
                 delays.push_back(latency);
             }
@@ -101,7 +117,8 @@ StridePrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
         // Miss in table
         // Find lowest confidence and replace
 
-        DPRINTF(HWPrefetch, "miss: PC %x blk_addr %x\n", pc, blk_addr);
+        DPRINTF(HWPrefetch, "miss: PC %x blk_addr %x (%s)\n", pc, blk_addr,
+                is_secure ? "s" : "ns");
 
         if (tab.size() >= 256) { //set default table size is 256
             std::list<StrideEntry*>::iterator min_pos = tab.begin();
@@ -112,7 +129,8 @@ StridePrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
                     min_conf = (*iter)->confidence;
                 }
             }
-            DPRINTF(HWPrefetch, "  replacing PC %x\n", (*min_pos)->instAddr);
+            DPRINTF(HWPrefetch, "  replacing PC %x (%s)\n",
+                    (*min_pos)->instAddr, (*min_pos)->isSecure ? "s" : "ns");
 
             // free entry and delete it
             delete *min_pos;
@@ -122,6 +140,7 @@ StridePrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
         StrideEntry *new_entry = new StrideEntry;
         new_entry->instAddr = pc;
         new_entry->missAddr = blk_addr;
+        new_entry->isSecure = is_secure;
         new_entry->stride = 0;
         new_entry->confidence = 0;
         tab.push_back(new_entry);