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Implement generic PFN list linking function
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This commit is contained in:
Aiken Harris
2026-01-01 20:40:45 +01:00
parent c080f74714
commit 7bcd78fdf3
3 changed files with 203 additions and 3 deletions
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3
xtoskrnl/includes/mm/pfn.hh
View File

@@ -31,6 +31,7 @@ namespace MM
STATIC LOADER_MEMORY_DESCRIPTOR OriginalFreeDescriptor;
STATIC PMMPFNLIST PageLocationList[];
STATIC PFN_NUMBER PfnDatabaseSize;
STATIC MMPFNLIST RomPagesList;
STATIC MMPFNLIST StandbyPagesList;
STATIC MMPFNLIST ZeroedPagesList;
@@ -53,6 +54,8 @@ namespace MM
STATIC XTAPI VOID IncrementAvailablePages(VOID);
STATIC XTAPI VOID InitializePageTablePfns(VOID);
STATIC XTAPI VOID LinkFreePage(IN PFN_NUMBER PageFrameIndex);
STATIC XTAPI VOID LinkPage(IN PMMPFNLIST ListHead,
IN PFN_NUMBER PageFrameIndex);
STATIC XTAPI VOID LinkPfnForPageTable(IN PFN_NUMBER PageFrameIndex,
IN PMMPTE PointerPte);
STATIC XTAPI VOID ProcessMemoryDescriptor(IN PFN_NUMBER BasePage,

9
xtoskrnl/mm/data.cc
View File

@@ -72,9 +72,6 @@ ULONGLONG MM::Pfn::NumberOfPhysicalPages;
/* Old biggest free memory descriptor */
LOADER_MEMORY_DESCRIPTOR MM::Pfn::OriginalFreeDescriptor;
/* List containing standby pages (clean, can be reclaimed or repurposed) */
MMPFNLIST MM::Pfn::StandbyPagesList = {0, StandbyPageList, MAXULONG_PTR, MAXULONG_PTR};
/* Array of pointers to PFN lists */
PMMPFNLIST MM::Pfn::PageLocationList[] = {&ZeroedPagesList,
&FreePagesList,
@@ -88,6 +85,12 @@ PMMPFNLIST MM::Pfn::PageLocationList[] = {&ZeroedPagesList,
/* Size of the PFN database in pages */
PFN_NUMBER MM::Pfn::PfnDatabaseSize;
/* List containing pages mapped as Read-Only (ROM) */
MMPFNLIST MM::Pfn::RomPagesList = {0, StandbyPageList, MAXULONG_PTR, MAXULONG_PTR};
/* List containing standby pages (clean, can be reclaimed or repurposed) */
MMPFNLIST MM::Pfn::StandbyPagesList = {0, StandbyPageList, MAXULONG_PTR, MAXULONG_PTR};
/* List containing free physical pages that have been zeroed out */
MMPFNLIST MM::Pfn::ZeroedPagesList = {0, ZeroedPageList, MAXULONG_PTR, MAXULONG_PTR};

194
xtoskrnl/mm/pfn.cc
View File

@@ -326,6 +326,200 @@ MM::Pfn::LinkFreePage(IN PFN_NUMBER PageFrameIndex)
IncrementAvailablePages();
}
/**
* Links a physical page to the appropriate list.
*
* @param ListHead
* Pointer to the list head.
*
* @param PageFrameIndex
* The Page Frame Number (PFN) of the page to link.
*
* @return This routine does not return any value.
*
* @since XT 1.0
*/
XTAPI
VOID
MM::Pfn::LinkPage(IN PMMPFNLIST ListHead,
IN PFN_NUMBER PageFrameIndex)
{
PMMCOLOR_TABLES ColorHead;
MMPAGELISTS ListName;
PMMPFN PageFrame;
/* Get the memory layout */
PMMMEMORY_LAYOUT MemoryLayout = MM::Manager::GetMemoryLayout();
/* Get the PFN database entry for the target page */
PageFrame = &((PMMPFN)MemoryLayout->PfnDatabaseAddress)[PageFrameIndex];
/* Get the list name */
ListName = ListHead->ListName;
/* Handle pages being linked to the modified or standby lists */
if(ListName == ModifiedPageList || ListName == StandbyPageList)
{
/* Detect an invalid prototype/transition PTE state */
if(!MM::Paging::GetPteSoftwarePrototype(&PageFrame->OriginalPte) &&
MM::Paging::GetPteSoftwareTransition(&PageFrame->OriginalPte))
{
/* Crash system due to corrupted PFN/PTE state */
KE::Crash::PanicEx(0x71, 0x8888, 0, 0, 0);
}
}
/* Check if the page is ROM */
if(PageFrame->u3.e1.Rom == 1)
{
/* Link the page to the ROM list */
ListHead = &RomPagesList;
ListHead->Total++;
/* Append the page to the end of the ROM list */
if(ListHead->Blink != MAXULONG_PTR)
{
/* Update the previous tail to point to this page */
(&((PMMPFN)MemoryLayout->PfnDatabaseAddress)[ListHead->Blink])->u1.Flink = PageFrameIndex;
}
else
{
/* Initialize the list if it was empty */
ListHead->Flink = PageFrameIndex;
}
/* Update list tail and PFN linkage */
ListHead->Blink = PageFrameIndex;
PageFrame->u1.Flink = MAXULONG_PTR;
PageFrame->u2.Blink = ListHead->Blink;
PageFrame->u3.e1.PageLocation = ListName;
/* ROM pages require no further processing */
return;
}
/* Account for the page being inserted into the target list */
ListHead->Total++;
/* Redirect modified pages to the per-color modified list */
if(ListHead == &ModifiedPagesList)
{
/* Select the modified list matching the page color */
ListHead = MM::Colors::GetModifiedPages(PageFrame->u3.e1.PageColor);
ListHead->Total++;
}
else if((PageFrame->u3.e1.RemovalRequested == 1) && (ListName <= StandbyPageList))
{
/* Undo the insertion into the current list */
ListHead->Total--;
/* Preserve the standby location for removed pages */
if(ListName == StandbyPageList)
{
/* Keep the page marked as standby */
PageFrame->u3.e1.PageLocation = StandbyPageList;
}
/* Mark the page as no longer cache-mapped */
PageFrame->u3.e1.CacheAttribute = PfnNotMapped;
/* Move the page to the bad page list */
ListHead = &BadPagesList;
ListHead->Total++;
ListName = BadPageList;
}
/* Insert zeroed pages at the head of the list */
if(ListName == ZeroedPageList)
{
/* Link the page as the new list head */
ListHead->Flink = PageFrameIndex;
/* Initialize PFN forward and backward links */
PageFrame->u1.Flink = ListHead->Flink;
PageFrame->u2.Blink = MAXULONG_PTR;
/* Update the previous head if it exists */
if(ListHead->Flink != MAXULONG_PTR)
{
/* Fix up the backward link of the old head */
(&((PMMPFN)MemoryLayout->PfnDatabaseAddress)[ListHead->Flink])->u2.Blink = PageFrameIndex;
}
else
{
/* Set the tail if the list was empty */
ListHead->Blink = PageFrameIndex;
}
}
else
{
/* Append the page to the tail of the list */
if(ListHead->Blink != MAXULONG_PTR)
{
/* Link the current tail to the new page */
(&((PMMPFN)MemoryLayout->PfnDatabaseAddress)[ListHead->Blink])->u1.Flink = PageFrameIndex;
}
else
{
/* Initialize the list if it was empty */
ListHead->Flink = PageFrameIndex;
}
/* Update list tail */
ListHead->Blink = PageFrameIndex;
/* Terminate PFN forward link and set backward link */
PageFrame->u1.Flink = MAXULONG_PTR;
PageFrame->u2.Blink = ListHead->Blink;
}
/* Record the page’s current location */
PageFrame->u3.e1.PageLocation = ListName;
/* Handle pages that contribute to the available page count */
if(ListName <= StandbyPageList)
{
/* Increment the system-wide available page counter */
MM::Pfn::IncrementAvailablePages();
/* Select the free list matching the page color */
ColorHead = MM::Colors::GetFreePages(ZeroedPageList, PageFrameIndex & MM::Colors::GetPagingColorsMask());
/* Store the color list linkage in the original PTE */
MM::Paging::SetPte(&PageFrame->OriginalPte, ColorHead->Flink);
PageFrame->u4.PteFrame = MM_PFN_PTE_FRAME;
/* Insert the page into the color free list */
ColorHead->Flink = PageFrameIndex;
/* Update the previous head or initialize the tail */
if(ColorHead->Flink != MAXULONG_PTR)
{
/* Fix up the PTE frame of the previous entry */
(&((PMMPFN)MemoryLayout->PfnDatabaseAddress)[ColorHead->Flink])->u4.PteFrame = PageFrameIndex;
}
else
{
/* Set the tail for an empty color list */
ColorHead->Blink = (PVOID)PageFrame;
}
/* Increment the color list page count */
ColorHead->Count++;
}
else if(ListName == ModifiedPageList)
{
/* Modified page insertion logic not implemented yet */
UNIMPLEMENTED;
}
else if(ListName == ModifiedReadOnlyPageList)
{
/* Modified read-only page handling not implemented yet */
UNIMPLEMENTED;
}
}
/**
* Initializes the PFN database entry for a physical page that is used as a page table.
*