From 4d398302c41b402cea25fd46f7e9c4bbb4d89fa2 Mon Sep 17 00:00:00 2001
From: Gabe Black <gabe.black@gmail.com>
Date: Sat, 11 Sep 2021 05:25:56 -0700
Subject: [PATCH] sim: Make the page shift a member of the MemPool class.

Pass it in through the constructor, rather than have the MemPool call
into the System object every time it needs the page shift. This is
simpler, more efficient, and removes a dependency between the MemPool
class and the System class.

Change-Id: I059bcb0db249251b32bff1beba3eadfe306d9081
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/50339
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---
 src/sim/mem_pool.cc | 16 ++++++++--------
 src/sim/mem_pool.hh |  4 ++--
 src/sim/system.cc   |  7 ++++---
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/sim/mem_pool.cc b/src/sim/mem_pool.cc
index 2614ad5ff8..f568e28a4a 100644
--- a/src/sim/mem_pool.cc
+++ b/src/sim/mem_pool.cc
@@ -33,14 +33,14 @@
 
 #include "sim/mem_pool.hh"
 
-#include "sim/system.hh"
+#include "base/logging.hh"
 
 namespace gem5
 {
 
-MemPool::MemPool(System *system, Addr ptr, Addr limit)
-        : sys(system), freePageNum(ptr >> sys->getPageShift()),
-        _totalPages(limit >> sys->getPageShift())
+MemPool::MemPool(Addr page_shift, Addr ptr, Addr limit)
+        : pageShift(page_shift), freePageNum(ptr >> page_shift),
+        _totalPages(limit >> page_shift)
 {
 }
 
@@ -59,7 +59,7 @@ MemPool::setFreePage(Counter value)
 Addr
 MemPool::freePageAddr() const
 {
-    return freePageNum << sys->getPageShift();
+    return freePageNum << pageShift;
 }
 
 Counter
@@ -83,19 +83,19 @@ MemPool::freePages() const
 Addr
 MemPool::allocatedBytes() const
 {
-    return allocatedPages() << sys->getPageShift();
+    return allocatedPages() << pageShift;
 }
 
 Addr
 MemPool::freeBytes() const
 {
-    return freePages() << sys->getPageShift();
+    return freePages() << pageShift;
 }
 
 Addr
 MemPool::totalBytes() const
 {
-    return totalPages() << sys->getPageShift();
+    return totalPages() << pageShift;
 }
 
 Addr
diff --git a/src/sim/mem_pool.hh b/src/sim/mem_pool.hh
index e8bd439156..49523f4e10 100644
--- a/src/sim/mem_pool.hh
+++ b/src/sim/mem_pool.hh
@@ -45,7 +45,7 @@ class System;
 class MemPool
 {
   private:
-    System *sys;
+    Addr pageShift;
 
     /** Page number to free memory. */
     Counter freePageNum;
@@ -54,7 +54,7 @@ class MemPool
     Counter _totalPages;
 
   public:
-    MemPool(System *system, Addr ptr, Addr limit);
+    MemPool(Addr page_shift, Addr ptr, Addr limit);
 
     Counter freePage() const;
     void setFreePage(Counter value);
diff --git a/src/sim/system.cc b/src/sim/system.cc
index 299ba66873..38952762b1 100644
--- a/src/sim/system.cc
+++ b/src/sim/system.cc
@@ -236,9 +236,10 @@ System::System(const Params &p)
             if (_m5opRange.valid()) {
                 // Make sure the m5op range is not included.
                 for (const auto &range: mem.exclude({_m5opRange}))
-                    memPools.emplace_back(this, range.start(), range.end());
+                    memPools.emplace_back(getPageShift(),
+                            range.start(), range.end());
             } else {
-                memPools.emplace_back(this, mem.start(), mem.end());
+                memPools.emplace_back(getPageShift(), mem.start(), mem.end());
             }
         }
 
@@ -468,7 +469,7 @@ System::unserialize(CheckpointIn &cp)
 
     assert(ptrs.size() == limits.size());
     for (size_t i = 0; i < ptrs.size(); i++)
-        memPools.emplace_back(this, ptrs[i], limits[i]);
+        memPools.emplace_back(getPageShift(), ptrs[i], limits[i]);
 
     // also unserialize the memories in the system
     physmem.unserializeSection(cp, "physmem");