SE: move page allocation from PageTable to Process

PageTable supported an allocate() call that called back
through the Process to allocate memory, but did not have
a method to map addresses without allocating new pages.
It makes more sense for Process to do the allocation, so
this method was renamed allocateMem() and moved to Process,
and uses a new map() call on PageTable.

The remaining uses of the process pointer in PageTable
were only to get the name and the PID, so by passing these
in directly in the constructor, we can make PageTable
completely independent of Process.

6 files changed, 24 insertions, 13 deletions

diff --git a/src/sim/process.cc b/src/sim/process.cc
index 62b9b7002..ba106fb63 100644
--- a/src/sim/process.cc
+++ b/src/sim/process.cc
@@ -169,7 +169,7 @@ Process::Process(ProcessParams * params)
 
     mmap_start = mmap_end = 0;
     nxm_start = nxm_end = 0;
-    pTable = new PageTable(this);
+    pTable = new PageTable(name(), M5_pid);
     // other parameters will be initialized when the program is loaded
 }
 
@@ -328,13 +328,21 @@ Process::sim_fd_obj(int tgt_fd)
     return &fd_map[tgt_fd];
 }
 
+void
+Process::allocateMem(Addr vaddr, int64_t size, bool clobber)
+{
+    int npages = divCeil(size, (int64_t)VMPageSize);
+    Addr paddr = system->allocPhysPages(npages);
+    pTable->map(vaddr, paddr, size, clobber);
+}
+
 bool
 Process::fixupStackFault(Addr vaddr)
 {
     // Check if this is already on the stack and there's just no page there
     // yet.
     if (vaddr >= stack_min && vaddr < stack_base) {
-        pTable->allocate(roundDown(vaddr, VMPageSize), VMPageSize);
+        allocateMem(roundDown(vaddr, VMPageSize), VMPageSize);
         return true;
     }
 
@@ -347,7 +355,7 @@ Process::fixupStackFault(Addr vaddr)
                 fatal("Maximum stack size exceeded\n");
             if (stack_base - stack_min > 8 * 1024 * 1024)
                 fatal("Over max stack size for one thread\n");
-            pTable->allocate(stack_min, TheISA::PageBytes);
+            allocateMem(stack_min, TheISA::PageBytes);
             inform("Increasing stack size by one page.");
         };
         return true;
diff --git a/src/sim/process.hh b/src/sim/process.hh
index d48b1b463..4c31597b4 100644
--- a/src/sim/process.hh
+++ b/src/sim/process.hh
@@ -212,6 +212,8 @@ class Process : public SimObject
 
     virtual void syscall(int64_t callnum, ThreadContext *tc) = 0;
 
+    void allocateMem(Addr vaddr, int64_t size, bool clobber = false);
+
     /// Attempt to fix up a fault at vaddr by allocating a page on the stack.
     /// @return Whether the fault has been fixed.
     bool fixupStackFault(Addr vaddr);
diff --git a/src/sim/syscall_emul.cc b/src/sim/syscall_emul.cc
index 6873d4aa4..203eaff2a 100644
--- a/src/sim/syscall_emul.cc
+++ b/src/sim/syscall_emul.cc
@@ -166,8 +166,7 @@ brkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
         for (ChunkGenerator gen(p->brk_point, new_brk - p->brk_point,
                                 VMPageSize); !gen.done(); gen.next()) {
             if (!p->pTable->translate(gen.addr()))
-                p->pTable->allocate(roundDown(gen.addr(), VMPageSize),
-                                    VMPageSize);
+                p->allocateMem(roundDown(gen.addr(), VMPageSize), VMPageSize);
 
             // if the address is already there, zero it out
             else {
diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index 9bcf58844..50bf1a52f 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -677,7 +677,7 @@ mremapFunc(SyscallDesc *desc, int callnum, LiveProcess *process, ThreadContext *
     if (new_length > old_length) {
         if ((start + old_length) == process->mmap_end) {
             uint64_t diff = new_length - old_length;
-            process->pTable->allocate(process->mmap_end, diff);
+            process->allocateMem(process->mmap_end, diff);
             process->mmap_end += diff;
             return start;
         } else {
@@ -691,15 +691,15 @@ mremapFunc(SyscallDesc *desc, int callnum, LiveProcess *process, ThreadContext *
                         process->mmap_end, process->mmap_end + new_length, new_length);
                 start = process->mmap_end;
                 // add on the remaining unallocated pages
-                process->pTable->allocate(start + old_length, new_length - old_length);
+                process->allocateMem(start + old_length,
+                                     new_length - old_length);
                 process->mmap_end += new_length;
                 warn("returning %08p as start\n", start);
                 return start;
             }
         }
     } else {
-        process->pTable->deallocate(start + new_length, old_length -
-                new_length);
+        process->pTable->unmap(start + new_length, old_length - new_length);
         return start;
     }
 }
@@ -1065,7 +1065,7 @@ mmapFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
         }
     }
 
-    p->pTable->allocate(start, length, clobber);
+    p->allocateMem(start, length, clobber);
 
     return start;
 }
diff --git a/src/sim/system.cc b/src/sim/system.cc
index 81a8a0574..c58830c10 100644
--- a/src/sim/system.cc
+++ b/src/sim/system.cc
@@ -275,10 +275,10 @@ System::replaceThreadContext(ThreadContext *tc, int context_id)
 
 #if !FULL_SYSTEM
 Addr
-System::new_page()
+System::allocPhysPages(int npages)
 {
     Addr return_addr = pagePtr << LogVMPageSize;
-    ++pagePtr;
+    pagePtr += npages;
     if (return_addr >= physmem->size())
         fatal("Out of memory, please increase size of physical memory.");
     return return_addr;
diff --git a/src/sim/system.hh b/src/sim/system.hh
index a6bc47fc0..ed5193dfd 100644
--- a/src/sim/system.hh
+++ b/src/sim/system.hh
@@ -287,7 +287,9 @@ class System : public SimObject
 
 #else
 
-    Addr new_page();
+    /// Allocate npages contiguous unused physical pages
+    /// @return Starting address of first page
+    Addr allocPhysPages(int npages);
 
 #endif // FULL_SYSTEM