106 lines
2.4 KiB
C
106 lines
2.4 KiB
C
/*
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* Copyright (c) 2026, Chloe M.
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* Provided under the BSD-3 clause.
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*
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* Description: Virtual address descriptor management
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* Author: Chloe M.
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*/
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#include <mm/vad.h>
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#include <hal/page.h>
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/* Prototypes */
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static LONG VadCmp(MM_VAD *V0, MM_VAD *V1);
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/* RBT generation */
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RB_PROTOTYPE(VadTree, _MM_VAD, TreeLink, VadCmp);
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RB_GENERATE(VadTree, _MM_VAD, TreeLink, VadCmp);
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static LONG
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VadCmp(MM_VAD *V0, MM_VAD *V1)
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{
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MM_RANGE *Range0, *Range1;
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Range0 = &V0->Range;
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Range1 = &V1->Range;
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return (Range0->VirtualBase < Range1->VirtualBase)
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? -1
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: Range0->VirtualBase > Range1->VirtualBase;
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}
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VOID
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MmVadTreeInit(MM_VAD_TREE *Tree)
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{
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if (Tree == NULL) {
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return;
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}
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Tree->Elements = 0;
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RB_INIT(&Tree->Head);
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}
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PT_STATUS
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MmVadTreeInsert(MM_VAD_TREE *Tree, MM_VAD *Vad)
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{
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if (Tree == NULL || Vad == NULL) {
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return STATUS_INVALID_PARAM;
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}
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RB_INSERT(VadTree, &Tree->Head, Vad);
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return STATUS_SUCCESS;
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}
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MM_VAD *
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MmVadTreeAllocate(MM_VAD_TREE *Tree, USIZE PageCount)
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{
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MM_VAD *VadBase, *VadIter;
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MM_VAD *VadTmp, *VadNext;
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MM_RANGE *RangeIter;
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UPTR RangeStart, RangeEnd;
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USIZE PagesFound = 0;
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USIZE RangeDelta;
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if (Tree == NULL || PageCount == 0) {
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return NULL;
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}
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VadBase = NULL;
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RB_FOREACH(VadIter, VadTree, &Tree->Head) {
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RangeIter = &VadIter->Range;
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RangeStart = RangeIter->VirtualBase;
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RangeEnd = RangeIter->VirtualBase + RangeIter->Length;
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RangeDelta = RangeEnd - RangeStart;
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/*
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* Do we have exactly a page here? Track that if so, otherwise
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* reset what we've already tracked.
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*/
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if (RangeDelta == PAGESIZE) {
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if (VadBase == NULL)
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VadBase = (MM_VAD *)RangeIter->VirtualBase;
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++PagesFound;
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} else {
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VadBase = NULL;
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--PagesFound;
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}
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/*
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* If we have found what we requested, remove the entire
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* range and return the base.
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*/
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if (PagesFound >= PageCount) {
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VadTmp = VadBase;
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while (VadTmp != VadIter) {
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VadNext = RB_NEXT(VadTree, &Tree->Head, VadTmp);
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RB_REMOVE(VadTree, &Tree->Head, VadTmp);
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VadTmp = VadNext;
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}
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RB_REMOVE(VadTree, &Tree->Head, VadTmp);
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return VadBase;
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}
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}
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return NULL;
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}
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