108 lines
2.2 KiB
C
108 lines
2.2 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: Pool allocator
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* Author: Chloe M.
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*/
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#ifndef _EX_POOL_H_
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#define _EX_POOL_H_ 1
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#include <ptdef.h>
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/* Maximum levels per region */
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#define POOL_LEVEL_MAX 8
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/* Minimum log2 granularity */
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#define POOL_MIN_LOG2 3
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/* Compute the granularity at a specific level */
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#define POOL_LEVEL_GRAN(X) \
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(1 << ((X) + POOL_MIN_LOG2))
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/*
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* Valid types that can be assigned to an allocated region
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*
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* @POOL_NON_PAGED: This type is not paged to disk
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*/
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typedef enum {
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POOL_NON_PAGED
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} POOL_TYPE;
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/*
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* A pool page represents a single allocatable
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* unit within a pool segment.
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*
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* @Bitmap: Bitmap within pool page [0=free, 1=allocated]
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* @Next: Next page within list
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*/
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typedef struct _POOL_PAGE {
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UQUAD Bitmap;
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struct _POOL_PAGE *Next;
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} POOL_PAGE;
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/*
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* A pool segment represents a list of pages at a specific
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* granularity.
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*
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* @FirstPage: Last page in segment
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* @PageCount: Number of pages in this segment
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*/
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typedef struct {
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POOL_PAGE *FirstPage;
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USIZE PageCount;
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} POOL_SEGMENT;
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/*
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* A pool region represents a whole area in which several
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* pool levels can reside.
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*
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* @Level: Segment levels
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*/
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typedef struct {
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POOL_SEGMENT Level[POOL_LEVEL_MAX];
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} POOL_REGION;
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/*
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* A pool header is prepended to the start of allocated
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* memory.
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*
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* @Gran: Granularity of page bitmap
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* @BitBase: Allocation bitbase
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* @SizeBytes: Allocation size in bytes
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* @Tag: Tag assigned to allocation
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* @Page: Page we reside in
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*/
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typedef struct {
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USHORT Gran;
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UCHAR BitBase : 6;
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USIZE SizeBytes;
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ULONG Tag;
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POOL_PAGE *Page;
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} POOL_HEADER;
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/*
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* Initialize a pool region
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*
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* @Region: Pool region to initialize
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*/
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VOID ExPoolRegionInit(POOL_REGION *Region);
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/*
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* Allocate a memory pool of a specific type and assign a tag
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* to it for verifying frees among other debugging needs.
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*
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* @Type: Pool type to assign
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* @ByteCount: Number of bytes to allocate
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* @Tag: Tag to assign to allocated memory
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*
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* Returns NULL upon failure.
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*/
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VOID *ExAllocatePoolWithTag(
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POOL_TYPE Type, USIZE ByteCount,
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ULONG Tag
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);
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#endif /* !_EX_POOL_H_ */
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