[ros-arm-bringup] 42220: - This is a HIGH RISK patch. It has been tested on multiple emulators and configurations but requires broader input. - Implement several changes to PFN database management: - The PTEs for the PFN Database are now created by ARM3. Unlike the old code which create PTE for every page on the machine, ARM3 only creates PTEs to account for pages that should be in the PFN database. - A second related change is what "pages should be in the PFN database". Previously, reserved or

Author: ros-arm-bringup
Date: Sat Jul 25 23:35:31 2009
New Revision: 42220

URL: http://svn.reactos.org/svn/reactos?rev=42220&view=rev
Log:
- This is a HIGH RISK patch. It has been tested on multiple emulators and configurations
but requires broader input.
- Implement several changes to PFN database management:
  - The PTEs for the PFN Database are now created by ARM3. Unlike the old code which
create PTE for every page on the machine, ARM3 only creates PTEs to account for pages that
should be in the PFN database.
  - A second related change is what "pages should be in the PFN database".
Previously, reserved or otherwise non-existing (ie: holes) memory regions would get a PFN
entry created and marked as "BIOS". This is wasteful and not compatible with
Windows: there should not be PFN entries created at all.
    - So we removed BIOS PFN entries, and now only create PTEs for valid pages as listed
in the physical memory ranges.
    - This allows machines with "holes" in their physical address space not to
waste dozens of MBs of nonpaged pool
    - Also saves memory on regular machines too, since 1-4MB worth of memory will now not
be in the DB anymore
  - To keep track of pages that are invalid/unknown/ignored, there is now a "PFN
Bitmap". This bitmap has one bit set for each valid PFN in the database.
    - And so, MiGetPfnEntry now also validates that, if there is a PFN Bitmap, the
requested PFN is actually present in the database.
  - This introduces a major functional change: device pages, reserved pages, and other
BIOS pages cannot be referenced, shared, or managed in any meaningful way.
    - We have attempted to fix parts of the OS that depended on this, but there may still
be bugs.
      - A known issue may be an assertion during reboot and/or shutdown in the hyperspace
mapping function. It is currently safe to simply "cont" in the debugger a couple
of times.
        - We are working on a fix.

Modified:
    trunk/reactos/ntoskrnl/include/internal/mm.h
    trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c
    trunk/reactos/ntoskrnl/mm/ARM3/miarm.h
    trunk/reactos/ntoskrnl/mm/freelist.c

Modified: trunk/reactos/ntoskrnl/include/internal/mm.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/include/internal/…
==============================================================================
--- trunk/reactos/ntoskrnl/include/internal/mm.h [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/include/internal/mm.h [iso-8859-1] Sat Jul 25 23:35:31 2009
@@ -1045,9 +1045,13 @@
 MiGetPfnEntry(IN PFN_TYPE Pfn)
 {
     PMMPFN Page;
+    extern RTL_BITMAP MiPfnBitMap;
 
     /* Make sure the PFN number is valid */
     if (Pfn > MmHighestPhysicalPage) return NULL;
+    
+    /* Make sure this page actually has a PFN entry */
+    if ((MiPfnBitMap.Buffer) && !(RtlTestBit(&MiPfnBitMap, Pfn))) return
NULL;
 
     /* Get the entry */
     Page = &MmPfnDatabase[Pfn];

Modified: trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/i386/init…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c [iso-8859-1] Sat Jul 25 23:35:31 2009
@@ -169,6 +169,20 @@
 // In Windows, this includes the Quark Color Table, but not in ARM³
 //
 ULONG MxPfnAllocation;
+
+//
+// Unlike the old ReactOS Memory Manager, ARM³ (and Windows) does not keep track
+// of pages that are not actually valid physical memory, such as ACPI reserved
+// regions, BIOS address ranges, or holes in physical memory address space which
+// could indicate device-mapped I/O memory.
+//
+// In fact, the lack of a PFN entry for a page usually indicates that this is
+// I/O space instead.
+//
+// A bitmap, called the PFN bitmap, keeps track of all page frames by assigning
+// a bit to each. If the bit is set, then the page is valid physical RAM.
+//
+RTL_BITMAP MiPfnBitMap;
 
 //
 // This structure describes the different pieces of RAM-backed address space
@@ -596,6 +610,9 @@
     ULONG OldCount;
     BOOLEAN IncludeType[LoaderMaximum];
     ULONG i;
+    PVOID Bitmap;
+    PPHYSICAL_MEMORY_RUN Run;
+    PFN_NUMBER FreePage, FreePageCount, PagesLeft, BasePage, PageCount;
     BoundaryAddressMultiple.QuadPart = 0;
     
     if (Phase == 0)
@@ -1108,9 +1125,138 @@
         // Now go ahead and initialize the ARM³ nonpaged pool
         //
         MiInitializeArmPool();
+
+        //
+        // Get current page data, since we won't be using MxGetNextPage as it
+        // would corrupt our state
+        //
+        FreePage = MxFreeDescriptor->BasePage;
+        FreePageCount = MxFreeDescriptor->PageCount;
+        PagesLeft = 0;
+        
+        //
+        // Loop the memory descriptors
+        //
+        NextEntry = KeLoaderBlock->MemoryDescriptorListHead.Flink;
+        while (NextEntry != &KeLoaderBlock->MemoryDescriptorListHead)
+        {
+            //
+            // Get the descriptor
+            //
+            MdBlock = CONTAINING_RECORD(NextEntry,
+                                        MEMORY_ALLOCATION_DESCRIPTOR,
+                                        ListEntry);
+            if ((MdBlock->MemoryType == LoaderFirmwarePermanent) ||
+                (MdBlock->MemoryType == LoaderBBTMemory) ||
+                (MdBlock->MemoryType == LoaderSpecialMemory))
+            {
+                //
+                // These pages are not part of the PFN database
+                //
+                NextEntry = MdBlock->ListEntry.Flink;
+                continue;
+            }
+            
+            //
+            // Next, check if this is our special free descriptor we've found
+            //
+            if (MdBlock == MxFreeDescriptor)
+            {
+                //
+                // Use the real numbers instead
+                //
+                BasePage = MxOldFreeDescriptor.BasePage;
+                PageCount = MxOldFreeDescriptor.PageCount;
+            }
+            else
+            {
+                //
+                // Use the descriptor's numbers
+                //
+                BasePage = MdBlock->BasePage;
+                PageCount = MdBlock->PageCount;
+            }
+            
+            //
+            // Get the PTEs for this range
+            //
+            PointerPte = MiAddressToPte(&MmPfnDatabase[BasePage]);
+            LastPte = MiAddressToPte(((ULONG_PTR)&MmPfnDatabase[BasePage +
PageCount]) - 1);
+            DPRINT("MD Type: %lx Base: %lx Count: %lx\n",
MdBlock->MemoryType, BasePage, PageCount);
+            
+            //
+            // Loop them
+            //
+            while (PointerPte <= LastPte)
+            {
+                //
+                // We'll only touch PTEs that aren't already valid
+                //
+                if (PointerPte->u.Hard.Valid == 0)
+                {
+                    //
+                    // Use the next free page
+                    //
+                    TempPte.u.Hard.PageFrameNumber = FreePage;
+                    ASSERT(FreePageCount != 0);
+                    
+                    //
+                    // Consume free pages
+                    //
+                    FreePage++;
+                    FreePageCount--;
+                    if (!FreePageCount)
+                    {
+                        //
+                        // Out of memory
+                        //
+                        KeBugCheckEx(INSTALL_MORE_MEMORY,
+                                     MmNumberOfPhysicalPages,
+                                     FreePageCount,
+                                     MxOldFreeDescriptor.PageCount,
+                                     1);
+                    }
+                    
+                    //
+                    // Write out this PTE
+                    //
+                    PagesLeft++;
+                    ASSERT(PointerPte->u.Hard.Valid == 0);
+                    ASSERT(TempPte.u.Hard.Valid == 1);
+                    *PointerPte = TempPte;
+                    
+                    //
+                    // Zero this page
+                    //
+                    RtlZeroMemory(MiPteToAddress(PointerPte), PAGE_SIZE);
+                }
+                
+                //
+                // Next!
+                //
+                PointerPte++;
+            }
+            
+            //
+            // Do the next address range
+            //
+            NextEntry = MdBlock->ListEntry.Flink;
+        }
+        
+        //
+        // Now update the free descriptors to consume the pages we used up during
+        // the PFN allocation loop
+        //
+        MxFreeDescriptor->BasePage = FreePage;
+        MxFreeDescriptor->PageCount = FreePageCount;
     }
     else if (Phase == 1) // IN BETWEEN, THE PFN DATABASE IS NOW CREATED
-    {        
+    {
+        //
+        // Reset the descriptor back so we can create the correct memory blocks
+        //
+        *MxFreeDescriptor = MxOldFreeDescriptor;
+        
         //
         // Initialize the nonpaged pool
         //
@@ -1197,16 +1343,57 @@
         //
         MmPhysicalMemoryBlock = MmInitializeMemoryLimits(LoaderBlock,
                                                          IncludeType);
+         
+        //
+        // Allocate enough buffer for the PFN bitmap
+        // Align it up to a 32-bit boundary
+        //
+        Bitmap = ExAllocatePoolWithTag(NonPagedPool,
+                                       (((MmHighestPhysicalPage + 1) + 31) / 32) * 4,
+                                       '  mM');
+        if (!Bitmap)
+        {
+            //
+            // This is critical
+            //
+            KeBugCheckEx(INSTALL_MORE_MEMORY,
+                         MmNumberOfPhysicalPages,
+                         MmLowestPhysicalPage,
+                         MmHighestPhysicalPage,
+                         0x101);
+        }
+        
+        //
+        // Initialize it and clear all the bits to begin with
+        //
+        RtlInitializeBitMap(&MiPfnBitMap,
+                            Bitmap,
+                            MmHighestPhysicalPage + 1);
+        RtlClearAllBits(&MiPfnBitMap);
+        
+        //
+        // Loop physical memory runs
+        //
         for (i = 0; i < MmPhysicalMemoryBlock->NumberOfRuns; i++)
         {
             //
-            // Dump it for debugging
-            //
-            PPHYSICAL_MEMORY_RUN Run;
+            // Get the run
+            //
             Run = &MmPhysicalMemoryBlock->Run[i];
             DPRINT("PHYSICAL RAM [0x%08p to 0x%08p]\n",
                    Run->BasePage << PAGE_SHIFT,
                    (Run->BasePage + Run->PageCount) << PAGE_SHIFT);
+
+            //
+            // Make sure it has pages inside it
+            //
+            if (Run->PageCount)
+            {
+                //
+                // Set the bits in the PFN bitmap
+                //
+                RtlSetBits(&MiPfnBitMap, Run->BasePage, Run->PageCount);
+            }
         }
         
         //

Modified: trunk/reactos/ntoskrnl/mm/ARM3/miarm.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/miarm.h?r…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/ARM3/miarm.h [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/ARM3/miarm.h [iso-8859-1] Sat Jul 25 23:35:31 2009
@@ -133,6 +133,7 @@
 extern MEMORY_ALLOCATION_DESCRIPTOR MxOldFreeDescriptor;
 extern ULONG MxPfnAllocation;
 extern MM_PAGED_POOL_INFO MmPagedPoolInfo;
+extern RTL_BITMAP MiPfnBitMap;
 
 VOID
 NTAPI

Modified: trunk/reactos/ntoskrnl/mm/freelist.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/freelist.c?rev…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/freelist.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/freelist.c [iso-8859-1] Sat Jul 25 23:35:31 2009
@@ -25,7 +25,6 @@
 
 #define MM_PHYSICAL_PAGE_FREE    (0x1)
 #define MM_PHYSICAL_PAGE_USED    (0x2)
-#define MM_PHYSICAL_PAGE_BIOS    (0x3)
 
 /* GLOBALS ****************************************************************/
 
@@ -98,6 +97,7 @@
 
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
    Page = MiGetPfnEntry(Pfn);
+   ASSERT(Page);
    ASSERT(Page->Flags.Type == MM_PHYSICAL_PAGE_USED);
    ASSERT(Page->Flags.Consumer == MC_USER);
    InsertTailList(&UserPageListHead, &Page->ListEntry);
@@ -115,6 +115,7 @@
 
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
    Page = MiGetPfnEntry(PreviousPfn);
+   ASSERT(Page);
    ASSERT(Page->Flags.Type == MM_PHYSICAL_PAGE_USED);
    ASSERT(Page->Flags.Consumer == MC_USER);
    NextListEntry = (PLIST_ENTRY)Page->ListEntry.Flink;
@@ -495,6 +496,7 @@
                 // Get the PFN entry for this page
                 //
                 Pfn1 = MiGetPfnEntry(Page);
+                ASSERT(Pfn1);
                 
                 //
                 // Make sure it's free and if this is our first pass, zeroed
@@ -591,6 +593,7 @@
         // Get the PFN entry for the page and check if we should zero it out
         //
         Pfn1 = MiGetPfnEntry(Page);
+        ASSERT(Pfn1);
         if (Pfn1->Flags.Zero == 0) MiZeroPage(Page);
     }
     
@@ -610,7 +613,7 @@
     PPHYSICAL_PAGE Pfn1;
     PCHAR State = "????", Consumer = "Unknown";
     KIRQL OldIrql;
-    ULONG Totals[5] = {0}, BiosPages = 0, FreePages = 0;
+    ULONG Totals[5] = {0}, FreePages = 0;
     
     KeRaiseIrql(HIGH_LEVEL, &OldIrql);
     
@@ -620,6 +623,7 @@
     for (i = 0; i <= MmHighestPhysicalPage; i++)
     {
         Pfn1 = MiGetPfnEntry(i);
+        if (!Pfn1) continue;
         
         //
         // Get the consumer
@@ -668,13 +672,6 @@
                 State = "Free";
                 Consumer = "Free";
                 FreePages++;
-                break;
-                
-            case MM_PHYSICAL_PAGE_BIOS:
-                
-                State = "BIOS";
-                Consumer = "System Reserved";
-                BiosPages++;
                 break;
         }
 
@@ -696,63 +693,24 @@
     DbgPrint("File System Cache:   %d pages\t[%d KB]\n", Totals[MC_CACHE], 
(Totals[MC_CACHE]  << PAGE_SHIFT) / 1024);
     DbgPrint("Process Working Set: %d pages\t[%d KB]\n", Totals[MC_USER],  
(Totals[MC_USER]   << PAGE_SHIFT) / 1024);
     DbgPrint("System:              %d pages\t[%d KB]\n", Totals[MC_SYSTEM],
(Totals[MC_SYSTEM] << PAGE_SHIFT) / 1024);
-    DbgPrint("BIOS:                %d pages\t[%d KB]\n", BiosPages,        
(BiosPages         << PAGE_SHIFT) / 1024);
     DbgPrint("Free:                %d pages\t[%d KB]\n", FreePages,        
(FreePages         << PAGE_SHIFT) / 1024);
     
     KeLowerIrql(OldIrql);
 }
 
-PFN_NUMBER
-NTAPI
-MxGetNextPage(IN PFN_NUMBER PageCount);
-
 VOID
 NTAPI
 MmInitializePageList(VOID)
 {
     ULONG i;
-    NTSTATUS Status;
-    PFN_TYPE Pfn = 0;
     PHYSICAL_PAGE UsedPage;
+    PMEMORY_ALLOCATION_DESCRIPTOR Md;
     PLIST_ENTRY NextEntry;
-    PMEMORY_ALLOCATION_DESCRIPTOR Md;
 
     /* Initialize the page lists */
     InitializeListHead(&UserPageListHead);
     InitializeListHead(&FreeUnzeroedPageListHead);
     InitializeListHead(&FreeZeroedPageListHead);
-
-    /* Loop every page required to hold the PFN database */
-    for (i = 0; i < MxPfnAllocation; i++)
-    {
-        PVOID Address = (char*)MmPfnDatabase + (i * PAGE_SIZE);
-
-        /* Check if FreeLDR has already allocated it for us */
-        if (!MmIsPagePresent(NULL, Address))
-        {
-            /* Use one of our highest usable pages */
-            Pfn = MxGetNextPage(1);
-
-            /* Set the PFN */
-            Status = MmCreateVirtualMappingForKernel(Address,
-                                                     PAGE_READWRITE,
-                                                     &Pfn,
-                                                     1);
-            if (!NT_SUCCESS(Status))
-            {
-                DPRINT1("Unable to create virtual mapping\n");
-                KeBugCheck(MEMORY_MANAGEMENT);
-            }
-        }
-        else
-        {
-            /* Setting the page protection is necessary to set the global bit */
-            MmSetPageProtect(NULL, Address, PAGE_READWRITE);
-        }
-    }
-
-    /* Clear the PFN database */
-    RtlZeroMemory(MmPfnDatabase, (MmHighestPhysicalPage + 1) * sizeof(PHYSICAL_PAGE));
 
     /* This is what a used page looks like */
     RtlZeroMemory(&UsedPage, sizeof(UsedPage));
@@ -779,17 +737,10 @@
             (Md->MemoryType == LoaderSpecialMemory) ||
             (Md->MemoryType == LoaderBad))
         {
-            /* Loop every page part of the block but valid in the database */
-            for (i = 0; i < Md->PageCount; i++)
-            {
-                /* Skip memory we ignore completely */
-                if ((Md->BasePage + i) > MmHighestPhysicalPage) break;
-                
-                /* These are pages reserved by the BIOS/ROMs */
-                MmPfnDatabase[Md->BasePage + i].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
-                MmPfnDatabase[Md->BasePage + i].Flags.Consumer = MC_NPPOOL;
-                MmStats.NrSystemPages++;
-            }
+            //
+            // We do not build PFN entries for this
+            //
+            continue;
         }
         else if ((Md->MemoryType == LoaderFree) ||
                  (Md->MemoryType == LoaderLoadedProgram) ||
@@ -872,13 +823,16 @@
    {
 	   oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
       Page = MiGetPfnEntry(Pfn);
-      if (Page->Flags.Type == MM_PHYSICAL_PAGE_FREE)
+      if (Page)
       {
-         DPRINT1("Mapping non-used page\n");
-         KeBugCheck(MEMORY_MANAGEMENT);
+          if (Page->Flags.Type == MM_PHYSICAL_PAGE_FREE)
+          {
+              DPRINT1("Mapping non-used page\n");
+              KeBugCheck(MEMORY_MANAGEMENT);
+          }
+          Page->MapCount++;
+          Page->ReferenceCount++;
       }
-      Page->MapCount++;
-      Page->ReferenceCount++;
       KeReleaseQueuedSpinLock(LockQueuePfnLock, oldIrql);
    }
 }
@@ -894,18 +848,21 @@
    {
 	  oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
       Page = MiGetPfnEntry(Pfn);
-      if (Page->Flags.Type == MM_PHYSICAL_PAGE_FREE)
+      if (Page)
       {
-         DPRINT1("Unmapping non-used page\n");
-         KeBugCheck(MEMORY_MANAGEMENT);
+          if (Page->Flags.Type == MM_PHYSICAL_PAGE_FREE)
+          {
+              DPRINT1("Unmapping non-used page\n");
+              KeBugCheck(MEMORY_MANAGEMENT);
+          }
+          if (Page->MapCount == 0)
+          {
+              DPRINT1("Unmapping not mapped page\n");
+              KeBugCheck(MEMORY_MANAGEMENT);
+          }
+          Page->MapCount--;
+          Page->ReferenceCount--;
       }
-      if (Page->MapCount == 0)
-      {
-         DPRINT1("Unmapping not mapped page\n");
-         KeBugCheck(MEMORY_MANAGEMENT);
-      }
-      Page->MapCount--;
-      Page->ReferenceCount--;
       KeReleaseQueuedSpinLock(LockQueuePfnLock, oldIrql);
    }
 }
@@ -952,6 +909,7 @@
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
 
    Page = MiGetPfnEntry(Pfn);
+   ASSERT(Page);
    if (Page->Flags.Type != MM_PHYSICAL_PAGE_USED)
    {
       DPRINT1("Referencing non-used page\n");
@@ -983,6 +941,7 @@
 
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
    Page = MiGetPfnEntry(Pfn);
+   ASSERT(Page);
    if (Page->Flags.Type != MM_PHYSICAL_PAGE_USED)
    {
       DPRINT1("Getting reference count for free page\n");
@@ -1017,6 +976,7 @@
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
     
    Page = MiGetPfnEntry(Pfn);
+   ASSERT(Page);
 
    if (Page->Flags.Type != MM_PHYSICAL_PAGE_USED)
    {
@@ -1088,6 +1048,7 @@
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
 
    Page = MiGetPfnEntry(Pfn);
+   ASSERT(Page);
    if (Page->Flags.Type != MM_PHYSICAL_PAGE_USED)
    {
       DPRINT1("Getting lock count for free page\n");
@@ -1112,6 +1073,7 @@
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
 
    Page = MiGetPfnEntry(Pfn);
+   ASSERT(Page);
    if (Page->Flags.Type != MM_PHYSICAL_PAGE_USED)
    {
       DPRINT1("Locking free page\n");
@@ -1143,6 +1105,7 @@
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
 
    Page = MiGetPfnEntry(Pfn);
+   ASSERT(Page);
    if (Page->Flags.Type != MM_PHYSICAL_PAGE_USED)
    {
       DPRINT1("Unlocking free page\n");
@@ -1173,7 +1136,7 @@
          /* Check if this allocation is for the PFN DB itself */
          if (MmStats.NrTotalPages == 0) 
          {
-             MxGetNextPage(1);
+             ASSERT(FALSE);
          }
 
          DPRINT1("MmAllocPage(): Out of memory\n");