[NTOS]: Kill some debug spew.
[reactos.git] / reactos / ntoskrnl / mm / ARM3 / pool.c
index 63e0b53..37cb2e5 100644 (file)
@@ -22,12 +22,108 @@ LIST_ENTRY MmNonPagedPoolFreeListHead[MI_MAX_FREE_PAGE_LISTS];
 PFN_NUMBER MmNumberOfFreeNonPagedPool, MiExpansionPoolPagesInitialCharge;
 PVOID MmNonPagedPoolEnd0;
 PFN_NUMBER MiStartOfInitialPoolFrame, MiEndOfInitialPoolFrame;
+KGUARDED_MUTEX MmPagedPoolMutex;
+MM_PAGED_POOL_INFO MmPagedPoolInfo;
+SIZE_T MmAllocatedNonPagedPool;
+ULONG MmSpecialPoolTag;
+ULONG MmConsumedPoolPercentage;
+BOOLEAN MmProtectFreedNonPagedPool;
 
 /* PRIVATE FUNCTIONS **********************************************************/
 
 VOID
 NTAPI
-MiInitializeArmPool(VOID)
+MiInitializeNonPagedPoolThresholds(VOID)
+{
+    PFN_NUMBER Size = MmMaximumNonPagedPoolInPages;
+
+    /* Default low threshold of 8MB or one third of nonpaged pool */
+    MiLowNonPagedPoolThreshold = (8 * _1MB) >> PAGE_SHIFT;
+    MiLowNonPagedPoolThreshold = min(MiLowNonPagedPoolThreshold, Size / 3);
+
+    /* Default high threshold of 20MB or 50% */
+    MiHighNonPagedPoolThreshold = (20 * _1MB) >> PAGE_SHIFT;
+    MiHighNonPagedPoolThreshold = min(MiHighNonPagedPoolThreshold, Size / 2);
+    ASSERT(MiLowNonPagedPoolThreshold < MiHighNonPagedPoolThreshold);
+}
+
+VOID
+NTAPI
+MiInitializePoolEvents(VOID)
+{
+    KIRQL OldIrql;
+    PFN_NUMBER FreePoolInPages;
+
+    /* Lock paged pool */
+    KeAcquireGuardedMutex(&MmPagedPoolMutex);
+
+    /* Total size of the paged pool minus the allocated size, is free */
+    FreePoolInPages = MmSizeOfPagedPoolInPages - MmPagedPoolInfo.AllocatedPagedPool;
+
+    /* Check the initial state high state */
+    if (FreePoolInPages >= MiHighPagedPoolThreshold)
+    {
+        /* We have plenty of pool */
+        KeSetEvent(MiHighPagedPoolEvent, 0, FALSE);
+    }
+    else
+    {
+        /* We don't */
+        KeClearEvent(MiHighPagedPoolEvent);
+    }
+
+    /* Check the initial low state */
+    if (FreePoolInPages <= MiLowPagedPoolThreshold)
+    {
+        /* We're very low in free pool memory */
+        KeSetEvent(MiLowPagedPoolEvent, 0, FALSE);
+    }
+    else
+    {
+        /* We're not */
+        KeClearEvent(MiLowPagedPoolEvent);
+    }
+
+    /* Release the paged pool lock */
+    KeReleaseGuardedMutex(&MmPagedPoolMutex);
+
+    /* Now it's time for the nonpaged pool lock */
+    OldIrql = KeAcquireQueuedSpinLock(LockQueueMmNonPagedPoolLock);
+
+    /* Free pages are the maximum minus what's been allocated */
+    FreePoolInPages = MmMaximumNonPagedPoolInPages - MmAllocatedNonPagedPool;
+
+    /* Check if we have plenty */
+    if (FreePoolInPages >= MiHighNonPagedPoolThreshold)
+    {
+        /* We do, set the event */
+        KeSetEvent(MiHighNonPagedPoolEvent, 0, FALSE);
+    }
+    else
+    {
+        /* We don't, clear the event */
+        KeClearEvent(MiHighNonPagedPoolEvent);
+    }
+
+    /* Check if we have very little */
+    if (FreePoolInPages <= MiLowNonPagedPoolThreshold)
+    {
+        /* We do, set the event */
+        KeSetEvent(MiLowNonPagedPoolEvent, 0, FALSE);
+    }
+    else
+    {
+        /* We don't, clear it */
+        KeClearEvent(MiLowNonPagedPoolEvent);
+    }
+
+    /* We're done, release the nonpaged pool lock */
+    KeReleaseQueuedSpinLock(LockQueueMmNonPagedPoolLock, OldIrql);
+}
+
+VOID
+NTAPI
+MiInitializeNonPagedPool(VOID)
 {
     ULONG i;
     PFN_NUMBER PoolPages;
@@ -120,6 +216,762 @@ MiInitializeArmPool(VOID)
     // guard page on top so make sure to skip it. The bottom guard page will be
     // guaranteed by the fact our size is off by one.
     //
+    MiInitializeSystemPtes(PointerPte + 1,
+                           MiExpansionPoolPagesInitialCharge,
+                           NonPagedPoolExpansion);
+}
+
+PVOID
+NTAPI
+MiAllocatePoolPages(IN POOL_TYPE PoolType,
+                    IN SIZE_T SizeInBytes)
+{
+    PFN_NUMBER SizeInPages, PageFrameNumber;
+    ULONG i;
+    KIRQL OldIrql;
+    PLIST_ENTRY NextEntry, NextHead, LastHead;
+    PMMPTE PointerPte, StartPte;
+    MMPTE TempPte;
+    PMMPFN Pfn1;
+    PVOID BaseVa, BaseVaStart;
+    PMMFREE_POOL_ENTRY FreeEntry;
+    PKSPIN_LOCK_QUEUE LockQueue;
+    
+    //
+    // Figure out how big the allocation is in pages
+    //
+    SizeInPages = BYTES_TO_PAGES(SizeInBytes);
+    
+    //
+    // Handle paged pool
+    //
+    if (PoolType == PagedPool)
+    {
+        //
+        // Lock the paged pool mutex
+        //
+        KeAcquireGuardedMutex(&MmPagedPoolMutex);
+        
+        //
+        // Find some empty allocation space
+        //
+        i = RtlFindClearBitsAndSet(MmPagedPoolInfo.PagedPoolAllocationMap,
+                                   SizeInPages,
+                                   MmPagedPoolInfo.PagedPoolHint);
+        if (i == 0xFFFFFFFF)
+        {
+            //
+            // Get the page bit count
+            //
+            i = ((SizeInPages - 1) / 1024) + 1;
+            DPRINT1("Paged pool expansion: %d %x\n", i, SizeInPages);
+            
+            //
+            // Check if there is enougn paged pool expansion space left
+            //
+            if (MmPagedPoolInfo.NextPdeForPagedPoolExpansion >
+                MiAddressToPte(MmPagedPoolInfo.LastPteForPagedPool))
+            {
+                //
+                // Out of memory!
+                //
+                DPRINT1("OUT OF PAGED POOL!!!\n");
+                KeReleaseGuardedMutex(&MmPagedPoolMutex);
+                return NULL;
+            }
+            
+            //
+            // Check if we'll have to expand past the last PTE we have available
+            //            
+            if (((i - 1) + MmPagedPoolInfo.NextPdeForPagedPoolExpansion) >
+                 MiAddressToPte(MmPagedPoolInfo.LastPteForPagedPool))
+            {
+                //
+                // We can only support this much then
+                //
+                SizeInPages = MiAddressToPte(MmPagedPoolInfo.LastPteForPagedPool) - 
+                              MmPagedPoolInfo.NextPdeForPagedPoolExpansion +
+                              1;
+                ASSERT(SizeInPages < i);
+                i = SizeInPages;
+            }
+            else
+            {
+                //
+                // Otherwise, there is plenty of space left for this expansion
+                //
+                SizeInPages = i;
+            }
+            
+            //
+            // Get the template PTE we'll use to expand
+            //
+            TempPte = ValidKernelPte;
+            
+            //
+            // Get the first PTE in expansion space
+            //
+            PointerPte = MmPagedPoolInfo.NextPdeForPagedPoolExpansion;
+            BaseVa = MiPteToAddress(PointerPte);
+            BaseVaStart = BaseVa;
+            
+            //
+            // Lock the PFN database and loop pages
+            //            
+            OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);          
+            do
+            {
+                //
+                // It should not already be valid
+                //
+                ASSERT(PointerPte->u.Hard.Valid == 0);
+                
+                /* Request a page */
+                PageFrameNumber = MiRemoveAnyPage(0);
+                TempPte.u.Hard.PageFrameNumber = PageFrameNumber;
+                
+                //
+                // Save it into our double-buffered system page directory
+                //
+                /* This seems to be making the assumption that one PDE is one page long */
+                C_ASSERT(PAGE_SIZE == (PD_COUNT * (sizeof(MMPTE) * PDE_COUNT)));
+                MmSystemPagePtes[(ULONG_PTR)PointerPte & (PAGE_SIZE - 1) /
+                                 sizeof(MMPTE)] = TempPte;
+                            
+                /* Initialize the PFN */
+                MiInitializePfnForOtherProcess(PageFrameNumber,
+                                               PointerPte,
+                                               MmSystemPageDirectory[(PointerPte - (PMMPTE)PDE_BASE) / PDE_COUNT]);
+                             
+                /* Write the actual PTE now */
+                ASSERT(TempPte.u.Hard.Valid == 1);
+                *PointerPte++ = TempPte;
+                
+                //
+                // Move on to the next expansion address
+                //
+                BaseVa = (PVOID)((ULONG_PTR)BaseVa + PAGE_SIZE);
+            } while (--i > 0);
+            
+            //
+            // Release the PFN database lock
+            //            
+            KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
+            
+            //
+            // These pages are now available, clear their availablity bits
+            //
+            RtlClearBits(MmPagedPoolInfo.PagedPoolAllocationMap,
+                         (MmPagedPoolInfo.NextPdeForPagedPoolExpansion -
+                          MiAddressToPte(MmPagedPoolInfo.FirstPteForPagedPool)) *
+                         1024,
+                         SizeInPages * 1024);
+                        
+            //
+            // Update the next expansion location
+            //
+            MmPagedPoolInfo.NextPdeForPagedPoolExpansion += SizeInPages;
+            
+            //
+            // Zero out the newly available memory
+            //
+            RtlZeroMemory(BaseVaStart, SizeInPages * PAGE_SIZE);
+            
+            //
+            // Now try consuming the pages again
+            //
+            SizeInPages = BYTES_TO_PAGES(SizeInBytes);
+            i = RtlFindClearBitsAndSet(MmPagedPoolInfo.PagedPoolAllocationMap,
+                                       SizeInPages,
+                                       0);
+            if (i == 0xFFFFFFFF) 
+            {
+                //
+                // Out of memory!
+                //
+                DPRINT1("OUT OF PAGED POOL!!!\n");
+                KeReleaseGuardedMutex(&MmPagedPoolMutex);
+                return NULL;
+            }
+        }
+        
+        //
+        // Update the pool hint if the request was just one page
+        //
+        if (SizeInPages == 1) MmPagedPoolInfo.PagedPoolHint = i + 1;
+        
+        //
+        // Update the end bitmap so we know the bounds of this allocation when
+        // the time comes to free it
+        //
+        RtlSetBit(MmPagedPoolInfo.EndOfPagedPoolBitmap, i + SizeInPages - 1);
+        
+        //
+        // Now we can release the lock (it mainly protects the bitmap)
+        //
+        KeReleaseGuardedMutex(&MmPagedPoolMutex);
+        
+        //
+        // Now figure out where this allocation starts
+        //
+        BaseVa = (PVOID)((ULONG_PTR)MmPagedPoolStart + (i << PAGE_SHIFT));
+        
+        //
+        // Flush the TLB
+        //
+        KeFlushEntireTb(TRUE, TRUE);
+        
+        /* Setup a demand-zero writable PTE */
+        MI_MAKE_SOFTWARE_PTE(&TempPte, MM_READWRITE);
+        
+        //
+        // Find the first and last PTE, then loop them all
+        //
+        PointerPte = MiAddressToPte(BaseVa);
+        StartPte = PointerPte + SizeInPages;
+        do
+        {
+            //
+            // Write the demand zero PTE and keep going
+            //
+            ASSERT(PointerPte->u.Hard.Valid == 0);
+            *PointerPte++ = TempPte;
+        } while (PointerPte < StartPte);
+        
+        //
+        // Return the allocation address to the caller
+        //
+        return BaseVa;
+    }    
+    
+    //
+    // Allocations of less than 4 pages go into their individual buckets
+    //
+    i = SizeInPages - 1;
+    if (i >= MI_MAX_FREE_PAGE_LISTS) i = MI_MAX_FREE_PAGE_LISTS - 1;
+   
+    //
+    // Loop through all the free page lists based on the page index
+    //
+    NextHead = &MmNonPagedPoolFreeListHead[i];
+    LastHead = &MmNonPagedPoolFreeListHead[MI_MAX_FREE_PAGE_LISTS];
+    
+    //
+    // Acquire the nonpaged pool lock
+    //
+    OldIrql = KeAcquireQueuedSpinLock(LockQueueMmNonPagedPoolLock);
+    do
+    {
+        //
+        // Now loop through all the free page entries in this given list
+        //
+        NextEntry = NextHead->Flink;
+        while (NextEntry != NextHead)
+        {
+            //
+            // Grab the entry and see if it can handle our allocation
+            //
+            FreeEntry = CONTAINING_RECORD(NextEntry, MMFREE_POOL_ENTRY, List);
+            if (FreeEntry->Size >= SizeInPages)
+            {
+                //
+                // It does, so consume the pages from here
+                //
+                FreeEntry->Size -= SizeInPages;
+
+                //
+                // The allocation will begin in this free page area
+                //
+                BaseVa = (PVOID)((ULONG_PTR)FreeEntry +
+                                 (FreeEntry->Size  << PAGE_SHIFT));
+                
+                //
+                // This is not a free page segment anymore
+                //
+                RemoveEntryList(&FreeEntry->List);
+                
+                //
+                // However, check if its' still got space left
+                //
+                if (FreeEntry->Size != 0)
+                {
+                    //
+                    // Insert it back into a different list, based on its pages
+                    //
+                    i = FreeEntry->Size - 1;
+                    if (i >= MI_MAX_FREE_PAGE_LISTS) i = MI_MAX_FREE_PAGE_LISTS - 1;
+                    InsertTailList (&MmNonPagedPoolFreeListHead[i],
+                                    &FreeEntry->List);
+                }
+                
+                //
+                // Grab the PTE for this allocation
+                //
+                PointerPte = MiAddressToPte(BaseVa);
+                ASSERT(PointerPte->u.Hard.Valid == 1);
+                
+                //
+                // Grab the PFN NextEntry and index
+                //
+                Pfn1 = MiGetPfnEntry(PFN_FROM_PTE(PointerPte));
+                
+                //
+                // Now mark it as the beginning of an allocation
+                //
+                ASSERT(Pfn1->u3.e1.StartOfAllocation == 0);
+                Pfn1->u3.e1.StartOfAllocation = 1;
+                
+                //
+                // Check if the allocation is larger than one page
+                //
+                if (SizeInPages != 1)
+                {
+                    //
+                    // Navigate to the last PFN entry and PTE
+                    //
+                    PointerPte += SizeInPages - 1;
+                    ASSERT(PointerPte->u.Hard.Valid == 1);
+                    Pfn1 = MiGetPfnEntry(PointerPte->u.Hard.PageFrameNumber);
+                }
+                
+                //
+                // Mark this PFN as the last (might be the same as the first)
+                //
+                ASSERT(Pfn1->u3.e1.EndOfAllocation == 0);
+                Pfn1->u3.e1.EndOfAllocation = 1;
+                
+                //
+                // Release the nonpaged pool lock, and return the allocation
+                //
+                KeReleaseQueuedSpinLock(LockQueueMmNonPagedPoolLock, OldIrql);
+                return BaseVa;
+            }
+            
+            //
+            // Try the next free page entry
+            //
+            NextEntry = FreeEntry->List.Flink;
+        }
+    } while (++NextHead < LastHead);
+    
+    //
+    // If we got here, we're out of space.
+    // Start by releasing the lock
+    //
+    KeReleaseQueuedSpinLock(LockQueueMmNonPagedPoolLock, OldIrql);
+
+    //
+    // Allocate some system PTEs
+    //
+    StartPte = MiReserveSystemPtes(SizeInPages, NonPagedPoolExpansion);
+    PointerPte = StartPte;
+    if (StartPte == NULL)
+    {
+        //
+        // Ran out of memory
+        //
+        DPRINT1("Out of NP Expansion Pool\n");
+        return NULL;
+    }
+    
+    //
+    // Acquire the pool lock now
+    //
+    OldIrql = KeAcquireQueuedSpinLock(LockQueueMmNonPagedPoolLock);
+    
+    //
+    // Lock the PFN database too
+    //
+    LockQueue = &KeGetCurrentPrcb()->LockQueue[LockQueuePfnLock];
+    KeAcquireQueuedSpinLockAtDpcLevel(LockQueue);
+    
+    //
+    // Loop the pages
+    //
+    TempPte = ValidKernelPte;
+    do
+    {
+        /* Allocate a page */
+        PageFrameNumber = MiRemoveAnyPage(0);
+        
+        /* Get the PFN entry for it and fill it out */
+        Pfn1 = MiGetPfnEntry(PageFrameNumber);
+        Pfn1->u3.e2.ReferenceCount = 1;
+        Pfn1->u2.ShareCount = 1;
+        Pfn1->PteAddress = PointerPte;
+        Pfn1->u3.e1.PageLocation = ActiveAndValid;
+        Pfn1->u4.VerifierAllocation = 0;
+        
+        /* Write the PTE for it */
+        TempPte.u.Hard.PageFrameNumber = PageFrameNumber;
+        ASSERT(PointerPte->u.Hard.Valid == 0);
+        ASSERT(TempPte.u.Hard.Valid == 1);
+        *PointerPte++ = TempPte;
+    } while (--SizeInPages > 0);
+    
+    //
+    // This is the last page
+    //
+    Pfn1->u3.e1.EndOfAllocation = 1;
+    
+    //
+    // Get the first page and mark it as such
+    //
+    Pfn1 = MiGetPfnEntry(StartPte->u.Hard.PageFrameNumber);
+    Pfn1->u3.e1.StartOfAllocation = 1;
+    
+    //
+    // Release the PFN and nonpaged pool lock
+    //
+    KeReleaseQueuedSpinLockFromDpcLevel(LockQueue);
+    KeReleaseQueuedSpinLock(LockQueueMmNonPagedPoolLock, OldIrql);
+    
+    //
+    // Return the address
+    //
+    return MiPteToAddress(StartPte);
+}
+
+ULONG
+NTAPI
+MiFreePoolPages(IN PVOID StartingVa)
+{
+    PMMPTE PointerPte, StartPte;
+    PMMPFN Pfn1, StartPfn;
+    PFN_NUMBER FreePages, NumberOfPages;
+    KIRQL OldIrql;
+    PMMFREE_POOL_ENTRY FreeEntry, NextEntry, LastEntry;
+    ULONG i, End;
+    
+    //
+    // Handle paged pool
+    //
+    if ((StartingVa >= MmPagedPoolStart) && (StartingVa <= MmPagedPoolEnd))
+    {
+        //
+        // Calculate the offset from the beginning of paged pool, and convert it
+        // into pages
+        //
+        i = ((ULONG_PTR)StartingVa - (ULONG_PTR)MmPagedPoolStart) >> PAGE_SHIFT;
+        End = i;
+        
+        //
+        // Now use the end bitmap to scan until we find a set bit, meaning that
+        // this allocation finishes here
+        //
+        while (!RtlTestBit(MmPagedPoolInfo.EndOfPagedPoolBitmap, End)) End++;
+        
+        //
+        // Now calculate the total number of pages this allocation spans
+        //
+        NumberOfPages = End - i + 1;
+        
+        /* Delete the actual pages */
+        PointerPte = MmPagedPoolInfo.FirstPteForPagedPool + i;
+        FreePages = MiDeleteSystemPageableVm(PointerPte, NumberOfPages, 0, NULL);
+        ASSERT(FreePages == NumberOfPages);
+        
+        //
+        // Acquire the paged pool lock
+        //
+        KeAcquireGuardedMutex(&MmPagedPoolMutex);
+        
+        //
+        // Clear the allocation and free bits
+        //
+        RtlClearBit(MmPagedPoolInfo.EndOfPagedPoolBitmap, i);
+        RtlClearBits(MmPagedPoolInfo.PagedPoolAllocationMap, i, NumberOfPages);
+        
+        //
+        // Update the hint if we need to
+        //
+        if (i < MmPagedPoolInfo.PagedPoolHint) MmPagedPoolInfo.PagedPoolHint = i;
+        
+        //
+        // Release the lock protecting the bitmaps
+        //
+        KeReleaseGuardedMutex(&MmPagedPoolMutex);
+        
+        //
+        // And finally return the number of pages freed
+        //
+        return NumberOfPages;
+    }
+    
+    //
+    // Get the first PTE and its corresponding PFN entry
+    //
+    StartPte = PointerPte = MiAddressToPte(StartingVa);
+    StartPfn = Pfn1 = MiGetPfnEntry(PointerPte->u.Hard.PageFrameNumber);
+    
+    //
+    // Loop until we find the last PTE
+    //
+    while (Pfn1->u3.e1.EndOfAllocation == 0)
+    {
+        //
+        // Keep going
+        //
+        PointerPte++;
+        Pfn1 = MiGetPfnEntry(PointerPte->u.Hard.PageFrameNumber);
+    }
+    
+    //
+    // Now we know how many pages we have
+    //
+    NumberOfPages = PointerPte - StartPte + 1;
+    
+    //
+    // Acquire the nonpaged pool lock
+    //
+    OldIrql = KeAcquireQueuedSpinLock(LockQueueMmNonPagedPoolLock);
+    
+    //
+    // Mark the first and last PTEs as not part of an allocation anymore
+    //
+    StartPfn->u3.e1.StartOfAllocation = 0;    
+    Pfn1->u3.e1.EndOfAllocation = 0;
+    
+    //
+    // Assume we will free as many pages as the allocation was
+    //
+    FreePages = NumberOfPages;
+    
+    //
+    // Peek one page past the end of the allocation
+    //
+    PointerPte++;
+    
+    //
+    // Guard against going past initial nonpaged pool
+    //
+    if (MiGetPfnEntryIndex(Pfn1) == MiEndOfInitialPoolFrame)
+    {
+        //
+        // This page is on the outskirts of initial nonpaged pool, so ignore it
+        //
+        Pfn1 = NULL;
+    }
+    else
+    {
+        //
+        // Otherwise, our entire allocation must've fit within the initial non 
+        // paged pool, or the expansion nonpaged pool, so get the PFN entry of
+        // the next allocation
+        //
+        ASSERT((ULONG_PTR)StartingVa + NumberOfPages <= (ULONG_PTR)MmNonPagedPoolEnd);
+        if (PointerPte->u.Hard.Valid == 1)
+        {
+            //
+            // It's either expansion or initial: get the PFN entry
+            //
+            Pfn1 = MiGetPfnEntry(PointerPte->u.Hard.PageFrameNumber);            
+        }
+        else
+        {
+            //
+            // This means we've reached the guard page that protects the end of
+            // the expansion nonpaged pool
+            //
+            Pfn1 = NULL;
+        }
+        
+    }
+    
+    //
+    // Check if this allocation actually exists
+    //
+    if ((Pfn1) && (Pfn1->u3.e1.StartOfAllocation == 0))
+    {
+        //
+        // It doesn't, so we should actually locate a free entry descriptor
+        //
+        FreeEntry = (PMMFREE_POOL_ENTRY)((ULONG_PTR)StartingVa +
+                                         (NumberOfPages << PAGE_SHIFT));
+        ASSERT(FreeEntry->Owner == FreeEntry);
+        
+        //
+        // Consume this entry's pages, and remove it from its free list
+        //
+        FreePages += FreeEntry->Size;
+        RemoveEntryList (&FreeEntry->List);
+    }
+    
+    //
+    // Now get the official free entry we'll create for the caller's allocation
+    //
+    FreeEntry = StartingVa;
+    
+    //
+    // Check if the our allocation is the very first page
+    //
+    if (MiGetPfnEntryIndex(StartPfn) == MiStartOfInitialPoolFrame)
+    {
+        //
+        // Then we can't do anything or we'll risk underflowing
+        //
+        Pfn1 = NULL;
+    }
+    else
+    {
+        //
+        // Otherwise, get the PTE for the page right before our allocation
+        //
+        PointerPte -= NumberOfPages + 1;
+        if (PointerPte->u.Hard.Valid == 1)
+        {
+            //
+            // It's either expansion or initial nonpaged pool, get the PFN entry
+            //
+            Pfn1 = MiGetPfnEntry(PointerPte->u.Hard.PageFrameNumber);
+        }
+        else
+        {
+            //
+            // We must've reached the guard page, so don't risk touching it
+            //
+            Pfn1 = NULL;
+        }
+    }
+    
+    //
+    // Check if there is a valid PFN entry for the page before the allocation
+    // and then check if this page was actually the end of an allocation.
+    // If it wasn't, then we know for sure it's a free page
+    //
+    if ((Pfn1) && (Pfn1->u3.e1.EndOfAllocation == 0))
+    {
+        //
+        // Get the free entry descriptor for that given page range
+        //
+        FreeEntry = (PMMFREE_POOL_ENTRY)((ULONG_PTR)StartingVa - PAGE_SIZE);
+        FreeEntry = FreeEntry->Owner;
+        
+        //
+        // Check if the entry is small enough to be indexed on a free list
+        // If it is, we'll want to re-insert it, since we're about to
+        // collapse our pages on top of it, which will change its count
+        //
+        if (FreeEntry->Size < (MI_MAX_FREE_PAGE_LISTS - 1))
+        {
+            //
+            // Remove the list from where it is now
+            //
+            RemoveEntryList(&FreeEntry->List);
+            
+            //
+            // Update its size
+            //
+            FreeEntry->Size += FreePages;
+            
+            //
+            // And now find the new appropriate list to place it in
+            //
+            i = (ULONG)(FreeEntry->Size - 1);
+            if (i >= MI_MAX_FREE_PAGE_LISTS) i = MI_MAX_FREE_PAGE_LISTS - 1;
+            
+            //
+            // Do it
+            //
+            InsertTailList(&MmNonPagedPoolFreeListHead[i], &FreeEntry->List);
+        }
+        else
+        {
+            //
+            // Otherwise, just combine our free pages into this entry
+            //
+            FreeEntry->Size += FreePages;
+        }
+    }
+    
+    //
+    // Check if we were unable to do any compaction, and we'll stick with this
+    //
+    if (FreeEntry == StartingVa)
+    {
+        //
+        // Well, now we are a free entry. At worse we just have our newly freed
+        // pages, at best we have our pages plus whatever entry came after us
+        //
+        FreeEntry->Size = FreePages;
+        
+        //
+        // Find the appropriate list we should be on
+        //
+        i = FreeEntry->Size - 1;
+        if (i >= MI_MAX_FREE_PAGE_LISTS) i = MI_MAX_FREE_PAGE_LISTS - 1;
+        
+        //
+        // And insert us
+        //
+        InsertTailList (&MmNonPagedPoolFreeListHead[i], &FreeEntry->List);
+    }
+    
+    //
+    // Just a sanity check
+    //
+    ASSERT(FreePages != 0);
+    
+    //
+    // Get all the pages between our allocation and its end. These will all now
+    // become free page chunks.
+    //
+    NextEntry = StartingVa;
+    LastEntry = (PMMFREE_POOL_ENTRY)((ULONG_PTR)NextEntry + (FreePages << PAGE_SHIFT));    
+    do
+    {
+        //
+        // Link back to the parent free entry, and keep going
+        //
+        NextEntry->Owner = FreeEntry;    
+        NextEntry = (PMMFREE_POOL_ENTRY)((ULONG_PTR)NextEntry + PAGE_SIZE);
+    } while (NextEntry != LastEntry);
+    
+    //
+    // We're done, release the lock and let the caller know how much we freed
+    //
+    KeReleaseQueuedSpinLock(LockQueueMmNonPagedPoolLock, OldIrql);
+    return NumberOfPages;
+}
+
+
+BOOLEAN
+NTAPI
+MiRaisePoolQuota(IN POOL_TYPE PoolType,
+                 IN ULONG CurrentMaxQuota,
+                 OUT PULONG NewMaxQuota)
+{
+    //
+    // Not implemented
+    //
+    UNIMPLEMENTED;
+    *NewMaxQuota = CurrentMaxQuota + 65536;
+    return TRUE;
+}
+
+/* PUBLIC FUNCTIONS ***********************************************************/
+
+/*
+ * @unimplemented
+ */
+PVOID
+NTAPI
+MmAllocateMappingAddress(IN SIZE_T NumberOfBytes,
+                         IN ULONG PoolTag)
+{
+       UNIMPLEMENTED;
+       return NULL;
+}
+
+/*
+ * @unimplemented
+ */
+VOID
+NTAPI
+MmFreeMappingAddress(IN PVOID BaseAddress,
+                     IN ULONG PoolTag)
+{
+       UNIMPLEMENTED;
 }
 
 /* EOF */