Paged memory management. More...

#include <core.h>
#include <libc/stdlib.h>
#include <libc/string.h>
#include <kernel/x86/cpu.h>
#include <kernel/interrupt/interrupt.h>
#include <kernel/mem/kmem.h>
#include <kernel/mem/pmap.h>
#include <kernel/mem/paging.h>

Data Structures
struct	pf_t
	The pf structure represents a record in the page frame database. More...

struct	pfdb
	The pfdb describes the state of the page frame database. More...

Macros
#define	CONTAINS_TABLE (1 << 0)

#define	PAGE_SHIFT 12

#define	PAGE_SHIFT_LARGE 21

#define	PFN_INVALID ((uint32_t)-1)

#define	PADDR_TO_PF(a) ((pf_t *)(pfdb.pf + ((a) >> PAGE_SHIFT)))

#define	PF_TO_PADDR(pf) ((uint64_t)((pf) - pfdb.pf) << PAGE_SHIFT)

#define	PFN_TO_PF(pfn) ((pf_t *)((pfn) + pfdb.pf))

#define	PF_TO_PFN(pf) ((uint32_t)((pf) - pfdb.pf))

#define	PTE_TO_PADDR(pte) ((pte) & ~PGMASK_OFFSET)

Enumerations

Functions
	STATIC_ASSERT (sizeof(pf_t)==32,"Unexpected page frame size")

static void *	reserve_region (const pmap_t *map, uint64_t size, uint32_t alignshift)
	Reserve an aligned region of memory managed by the memory table module. More...

void	page_init ()
	Initialize the page frame database. More...

static pf_t *	pfalloc ()

static void	pffree (pf_t *pf)

static uint64_t	pgalloc ()

static void	pgfree (uint64_t paddr)

static void	pgfree_recurse (page_t *page, int level)

static void	add_pte (pagetable_t *pt, uint64_t vaddr, uint64_t paddr, uint32_t pflags, uint32_t addflags)
	Add to the page table an entry mapping a virtual address to a physical address. More...

static uint64_t	remove_pte (pagetable_t *pt, uint64_t vaddr)

void	pagetable_create (pagetable_t pt, void vaddr, uint64_t size)
	Create a new page table that can be used to associate virtual addresses with physical addresses. More...

void	pagetable_destroy (pagetable_t *pt)
	Destroy a page table. More...

void	pagetable_activate (pagetable_t *pt)
	Activate a page table on the CPU, so all virtual memory operations are performed relative to the page table. More...

void *	page_alloc (pagetable_t pt, void vaddr_in, int count)
	Allocate one or more pages contiguous in virtual memory. More...

void	page_free (pagetable_t pt, void vaddr_in, int count)
	Free one or more contiguous pages from virtual memory. More...

Variables
static struct pfdb	pfdb

static pagetable_t	kpt

static pagetable_t *	active_pt

Detailed Description

Paged memory management.

Definition in file paging.c.

Data Structure Documentation

struct pf_t

The pf structure represents a record in the page frame database.

Definition at line 45 of file paging.c.

Data Fields
uint32_t	prev	Index of prev pfn on available list.
uint32_t	next	Index of next pfn on available list.
uint16_t	refcount	Number of references to this page.
uint16_t	sharecount	Number of processes sharing page.
uint16_t	flags
uint8_t	type	PFTYPE of page frame.
uint8_t	reserved0
uint64_t	reserved1
uint64_t	reserved2

struct pfdb

The pfdb describes the state of the page frame database.

Definition at line 61 of file paging.c.

Data Fields
pf_t *	pf	Pointer to array of page frames.
uint32_t	count	Total number of frames in the pfdb.
uint32_t	avail	Available number of frames in the pfdb.
uint32_t	head	Index of available frame list head.
uint32_t	tail	Index of available frame list tail.

Macro Definition Documentation

#define CONTAINS_TABLE (1 << 0)

Definition at line 20 of file paging.c.

Referenced by add_pte().

#define PAGE_SHIFT 12

Definition at line 23 of file paging.c.

Referenced by page_init().

#define PAGE_SHIFT_LARGE 21

Definition at line 24 of file paging.c.

Referenced by page_init().

#define PFN_INVALID ((uint32_t)-1)

Definition at line 27 of file paging.c.

Referenced by page_init(), pfalloc(), and pffree().

#define PADDR_TO_PF ( a ) ((pf_t *)(pfdb.pf + ((a) >> PAGE_SHIFT)))

Definition at line 30 of file paging.c.

Referenced by pgfree(), and pgfree_recurse().

#define PF_TO_PADDR ( pf ) ((uint64_t)((pf) - pfdb.pf) << PAGE_SHIFT)

Definition at line 31 of file paging.c.

Referenced by pgalloc().

#define PFN_TO_PF ( pfn ) ((pf_t *)((pfn) + pfdb.pf))

Definition at line 32 of file paging.c.

Referenced by page_init(), and pfalloc().

#define PF_TO_PFN ( pf ) ((uint32_t)((pf) - pfdb.pf))

Definition at line 33 of file paging.c.

Referenced by pffree().

#define PTE_TO_PADDR ( pte ) ((pte) & ~PGMASK_OFFSET)

Definition at line 34 of file paging.c.

Referenced by pgfree_recurse().

Enumeration Type Documentation

anonymous enum

Enumerator
PFTYPE_RESERVED
PFTYPE_AVAILABLE
PFTYPE_ALLOCATED

Definition at line 37 of file paging.c.

Function Documentation

STATIC_ASSERT	(	sizeof(pf_t)	= `=32`,
		"Unexpected page frame size"
	)

static void* reserve_region	(	const pmap_t *	map,
		uint64_t	size,
		uint32_t	alignshift
	)

static

Reserve an aligned region of memory managed by the memory table module.

Definition at line 78 of file paging.c.

Referenced by page_init().

void page_init ( )

Initialize the page frame database.

The page frame database manages the physical memory used by all memory pages known to the kernel.

Definition at line 107 of file paging.c.

Referenced by kmain().

static pf_t* pfalloc ( )

static

Definition at line 180 of file paging.c.

Referenced by pgalloc().

static void pffree ( pf_t * pf )

static

Definition at line 202 of file paging.c.

Referenced by pgfree().

static uint64_t pgalloc ( )

static

Definition at line 222 of file paging.c.

Referenced by add_pte(), page_alloc(), and pagetable_create().

static void pgfree ( uint64_t paddr )

static

Definition at line 236 of file paging.c.

Referenced by page_free(), and pgfree_recurse().

static void pgfree_recurse	(	page_t *	page,
		int	level
	)

static

Definition at line 244 of file paging.c.

Referenced by pagetable_destroy().

static void add_pte	(	pagetable_t *	pt,
		uint64_t	vaddr,
		uint64_t	paddr,
		uint32_t	pflags,
		uint32_t	addflags
	)

static

Add to the page table an entry mapping a virtual address to a physical address.

Definition at line 276 of file paging.c.

Referenced by page_alloc().

static uint64_t remove_pte	(	pagetable_t *	pt,
		uint64_t	vaddr
	)

static

Definition at line 337 of file paging.c.

Referenced by page_free().

void pagetable_create	(	pagetable_t *	pt,
		void *	vaddr,
		uint64_t	size
	)

Create a new page table that can be used to associate virtual addresses with physical addresses.

The page table includes protected mappings for kernel memory.

Parameters

[in]	pt	A pointer to the pagetable structure that will hold the page table.
[in]	vaddr	The virtual address within the new page table where the page table will be mapped.
[in]	size	Maximum size of the page table in bytes. Must be a multiple of PAGE_SIZE.

Returns: A handle to the created page table.

Definition at line 364 of file paging.c.

Referenced by cmd_test_heap().

void pagetable_destroy ( pagetable_t * pt )

Destroy a page table.

Parameters

[in] pt A handle to the page table to destroy.

Definition at line 383 of file paging.c.

Referenced by cmd_test_heap().

void pagetable_activate ( pagetable_t * pt )

Activate a page table on the CPU, so all virtual memory operations are performed relative to the page table.

Parameters

[in] pt A handle to the activated page table. Pass NULL to activate the kernel page table.

Definition at line 403 of file paging.c.

Referenced by cmd_test_heap().

void* page_alloc	(	pagetable_t *	pt,
		void *	vaddr,
		int	count
	)

Allocate one or more pages contiguous in virtual memory.

Parameters

[in]	pt	Handle to the page table from which to allocate the page(s).
[in]	vaddr	The virtual address of the first allocated page.
[in]	count	The number of contiguous virtual memory pages to allocate.

Returns: A virtual memory pointer to the first page allocated.

Definition at line 415 of file paging.c.

Referenced by grow_heap(), and heap_create().

void page_free	(	pagetable_t *	pt,
		void *	vaddr,
		int	count
	)

Free one or more contiguous pages from virtual memory.

Parameters

[in]	pt	Handle to ehte page table from which to free the page(s).
[in]	vaddr	The virtual address of the first allocated page.
[in]	count	The number of contiguous virtual memory pages to free.

Definition at line 425 of file paging.c.

Referenced by heap_destroy().