[ros-arm-bringup] 39938: - Rework Hyperspace Mapping Interface for Page zeroing. It is now more efficient and adapted to ReactOS. - This also fixes some race conditions. - There was a lot of difficulty getting this patch through because of everyone else adding their 2 cents to the code. Next time, wait.

Author: ros-arm-bringup
Date: Tue Mar 10 23:52:39 2009
New Revision: 39938

URL: http://svn.reactos.org/svn/reactos?rev=39938&view=rev
Log:
- Rework Hyperspace Mapping Interface for Page zeroing. It is now more efficient and
adapted to ReactOS.
- This also fixes some race conditions.
- There was a lot of difficulty getting this patch through because of everyone else adding
their 2 cents to the code. Next time, wait. 


Modified:
    trunk/reactos/ntoskrnl/include/internal/mm.h
    trunk/reactos/ntoskrnl/mm/hypermap.c
    trunk/reactos/ntoskrnl/mm/i386/page.c
    trunk/reactos/ntoskrnl/mm/kmap.c
    trunk/reactos/ntoskrnl/mm/section.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] Tue Mar 10 23:52:39 2009
@@ -65,6 +65,8 @@
 #define MI_MAPPING_RANGE_START              (ULONG)HYPER_SPACE
 #define MI_MAPPING_RANGE_END                (MI_MAPPING_RANGE_START + \
                                              MI_HYPERSPACE_PTES * PAGE_SIZE)
+#define MI_ZERO_PTE                         (PMMPTE)(MI_MAPPING_RANGE_END + \
+                                             PAGE_SIZE)
 
 /* Signature of free pool blocks */
 #define MM_FREE_POOL_TAG    TAG('F', 'r', 'p', 'l')
@@ -1086,11 +1088,7 @@
 
 PVOID
 NTAPI
-MiMapPagesToZeroInHyperSpace(IN PFN_NUMBER Page);
-
-VOID
-NTAPI
-MiUnmapPagesInZeroSpace(IN PVOID Address);
+MiMapPageToZeroInHyperSpace(IN PFN_NUMBER Page);
 
 //
 // ReactOS Compatibility Layer

Modified: trunk/reactos/ntoskrnl/mm/hypermap.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/hypermap.c?rev…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/hypermap.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/hypermap.c [iso-8859-1] Tue Mar 10 23:52:39 2009
@@ -130,11 +130,10 @@
 
 PVOID
 NTAPI
-MiMapPagesToZeroInHyperSpace(IN PFN_NUMBER Page)
+MiMapPageToZeroInHyperSpace(IN PFN_NUMBER Page)
 {
     MMPTE TempPte;
     PMMPTE PointerPte;
-    PFN_NUMBER Offset;
     PVOID Address; 
     
     //
@@ -149,49 +148,24 @@
     TempPte.u.Hard.PageFrameNumber = Page;
     
     //
-    // Pick the first hyperspace PTE
+    // Get the Zero PTE and its address
     //
-    PointerPte = MmFirstReservedMappingPte;
-
-    //
-    // Now get the first free PTE
-    //
-    Offset = PFN_FROM_PTE(PointerPte);
-    if (!Offset)
-    {
-        //
-        // Reset the PTEs
-        //
-        Offset = MI_HYPERSPACE_PTES;
-        KeFlushProcessTb();
-    }
+    PointerPte = MiAddressToPte(MI_ZERO_PTE);
+    Address = (PVOID)((ULONG_PTR)PointerPte << 10);
     
     //
-    // Prepare the next PTE
+    // Invalidate the old address
     //
-    PointerPte->u.Hard.PageFrameNumber = Offset - 1;
+    __invlpg(Address);
     
     //
     // Write the current PTE
     //
-    PointerPte += Offset;
-    ASSERT(PointerPte->u.Hard.Valid == 0);
-    ASSERT(TempPte.u.Hard.Valid == 1);
+    TempPte.u.Hard.PageFrameNumber = Page;
     *PointerPte = TempPte;
     
     //
     // Return the address
     //
-    Address = (PVOID)((ULONG_PTR)PointerPte << 10);
     return Address;
 }
-
-VOID
-NTAPI
-MiUnmapPagesInZeroSpace(IN PVOID Address)
-{
-    //
-    // Blow away the mapping
-    //
-    MiAddressToPte(Address)->u.Long = 0;
-}

Modified: trunk/reactos/ntoskrnl/mm/i386/page.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/i386/page.c?re…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/i386/page.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/i386/page.c [iso-8859-1] Tue Mar 10 23:52:39 2009
@@ -783,6 +783,7 @@
         DPRINT1("Setting kernel address with process context\n");
         KeBugCheck(MEMORY_MANAGEMENT);
     }
+
     if (SwapEntry & (1 << 31))
     {
         KeBugCheck(MEMORY_MANAGEMENT);
@@ -1086,7 +1087,7 @@
     
     if (Process != NULL && Process != PsGetCurrentProcess())
     {
-        Pde =
MiMapPagesToZeroInHyperSpace(PTE_TO_PFN(Process->Pcb.DirectoryTableBase[0]));
+        Pde =
MiMapPageToZeroInHyperSpace(PTE_TO_PFN(Process->Pcb.DirectoryTableBase[0]));
     }
     else
     {
@@ -1098,10 +1099,6 @@
         {
             InterlockedCompareExchangePte(&Pde[Offset],
MmGlobalKernelPageDirectory[Offset], 0);
         }
-    }
-    if (Pde != (PULONG)PAGEDIRECTORY_MAP)
-    {
-        MiUnmapPagesInZeroSpace(Pde);
     }
 }
 

Modified: trunk/reactos/ntoskrnl/mm/kmap.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/kmap.c?rev=399…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/kmap.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/kmap.c [iso-8859-1] Tue Mar 10 23:52:39 2009
@@ -22,13 +22,12 @@
 {
    PVOID TempAddress;
 
-   TempAddress = MiMapPagesToZeroInHyperSpace(Page);
+   TempAddress = MiMapPageToZeroInHyperSpace(Page);
    if (TempAddress == NULL)
    {
       return(STATUS_NO_MEMORY);
    }
    memset(TempAddress, 0, PAGE_SIZE);
-   MiUnmapPagesInZeroSpace(TempAddress);
    return(STATUS_SUCCESS);
 }
 

Modified: trunk/reactos/ntoskrnl/mm/section.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/section.c?rev=…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/section.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/section.c [iso-8859-1] Tue Mar 10 23:52:39 2009
@@ -691,7 +691,7 @@
             return Status;
          }
       }
-      PageAddr = MiMapPagesToZeroInHyperSpace(*Page);
+      PageAddr = MiMapPageToZeroInHyperSpace(*Page);
       CacheSegOffset = BaseOffset + CacheSeg->Bcb->CacheSegmentSize - FileOffset;
       Length = RawLength - SegOffset;
       if (Length <= CacheSegOffset && Length <= PAGE_SIZE)
@@ -714,7 +714,6 @@
                                        &CacheSeg);
          if (!NT_SUCCESS(Status))
          {
-            MiUnmapPagesInZeroSpace(PageAddr);
             return(Status);
          }
          if (!UptoDate)
@@ -727,7 +726,6 @@
             if (!NT_SUCCESS(Status))
             {
                CcRosReleaseCacheSegment(Bcb, CacheSeg, FALSE, FALSE, FALSE);
-               MiUnmapPagesInZeroSpace(PageAddr);
                return Status;
             }
          }
@@ -741,7 +739,6 @@
          }
       }
       CcRosReleaseCacheSegment(Bcb, CacheSeg, TRUE, FALSE, FALSE);
-      MiUnmapPagesInZeroSpace(PageAddr);
    }
    return(STATUS_SUCCESS);
 }