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Page Table

include/mem/page_table.h View source View on GitHub

Structs

Section titled “Structs”

pte_tagged

Section titled “pte_tagged”
struct pte_tagged (2 fields) source

This is a bit like a tagged pointer, just that the payload moseys around LOCK_BIT and AVAIL2, and the type sits right above PRESENT

The layout is effectively

[ payload higher ] [ LOCK + AVAIL2 ] [ payload lower ] [ type ] [ P = 0 ]

§ enum pte_tag_type type
§ uint64_t payload
NOTE

higher 5 bits MUST be zero

Enums

Section titled “Enums”

pte_tag_type

Section titled “pte_tag_type”
enum pte_tag_type : uint8_t (2 variants) source

Packed into the low X bits

§ PTE_TAG_TYPE_NONE = 0
§ PTE_TAG_TYPE_DEMAND_PAGED = 1

Type Aliases

Section titled “Type Aliases”

pte_atomic_t

Section titled “pte_atomic_t”
typedef atomic_uint64_t pte_atomic_t
source

Functions

Section titled “Functions”

pte_is_shared

Section titled “pte_is_shared”
bool pte_is_shared(uint64_t pte)
source

pte_tagged_check

Section titled “pte_tagged_check”
void pte_tagged_check(struct pte_tagged *pt)
source

pte_tagged_pack

Section titled “pte_tagged_pack”
uint64_t pte_tagged_pack(struct pte_tagged *pt)
source

pte_tagged_unpack

Section titled “pte_tagged_unpack”
struct pte_tagged pte_tagged_unpack(pte_t pte)
source

pte_locked

Section titled “pte_locked”
bool pte_locked(pte_atomic_t *pte)
source

pte_read

Section titled “pte_read”
uint64_t pte_read(pte_atomic_t *pte)
source

pte_or

Section titled “pte_or”
uint64_t pte_or(pte_atomic_t *pte, uint64_t val)
source

pte_unlock_internal

Section titled “pte_unlock_internal”
void pte_unlock_internal(pte_atomic_t *pte)
source

pte_lock_internal

Section titled “pte_lock_internal”
void pte_lock_internal(pte_atomic_t *pte)
source
TODO

use bit_spinlock.h

pte_lock_irql

Section titled “pte_lock_irql”
enum irql pte_lock_irql(pte_atomic_t *pte)
source

pte_unlock_irql

Section titled “pte_unlock_irql”
void pte_unlock_irql(pte_atomic_t *pte, enum irql old_irql)
source

pte_has_tag

Section titled “pte_has_tag”
bool pte_has_tag(pte_atomic_t *pte)
source

pte_tag_pte

Section titled “pte_tag_pte”
uint64_t pte_tag_pte(pte_atomic_t *pte, struct pte_tagged *ptag)
source

pte_read_tag

Section titled “pte_read_tag”
struct pte_tagged pte_read_tag(pte_atomic_t *pte)
source

pte_in_use

Section titled “pte_in_use”
bool pte_in_use(pte_atomic_t *pte)
source

Macros

Section titled “Macros”

PT_LEVELS

Section titled “PT_LEVELS”
#define PT_LEVELS 4
source

PT_SHIFT_L1

Section titled “PT_SHIFT_L1”
#define PT_SHIFT_L1 12
source

PT_SHIFT_L2

Section titled “PT_SHIFT_L2”
#define PT_SHIFT_L2 21
source

PT_SHIFT_L3

Section titled “PT_SHIFT_L3”
#define PT_SHIFT_L3 30
source

PT_SHIFT_L4

Section titled “PT_SHIFT_L4”
#define PT_SHIFT_L4 39
source

PT_STRIDE

Section titled “PT_STRIDE”
#define PT_STRIDE 9
source

PTE_LOCK_SHIFT

Section titled “PTE_LOCK_SHIFT”
#define PTE_LOCK_SHIFT 9
source

PTE_AVAIL2_SHIFT

Section titled “PTE_AVAIL2_SHIFT”
#define PTE_AVAIL2_SHIFT 10
source

PTE_LOCK_BIT

Section titled “PTE_LOCK_BIT”
#define PTE_LOCK_BIT BIT(PTE_LOCK_SHIFT)
source

PTE_AVAIL2_BIT

Section titled “PTE_AVAIL2_BIT”
#define PTE_AVAIL2_BIT BIT(PTE_AVAIL2_SHIFT)
source

PTE_SHARED_SHIFT

Section titled “PTE_SHARED_SHIFT”
#define PTE_SHARED_SHIFT 11
source

Mark an entry whose child table is shared with other entries, this is what we use in aliasing. The subtree should never be freed through this entry, since every other entry pointing at it would see the change too. This should only ever be set on present entries

PTE_SHARED_BIT

Section titled “PTE_SHARED_BIT”
#define PTE_SHARED_BIT BIT(PTE_SHARED_SHIFT)
source

PTE_TAGGED_TYPE_SHIFT

Section titled “PTE_TAGGED_TYPE_SHIFT”
#define PTE_TAGGED_TYPE_SHIFT (PAGE_PRESENT_SHIFT + 1)
source

Packed layout:

bit  0       P = 0
bits 1-2     type
bits 3-8     payload low  (6 bits)
bit  9       LOCK    (not payload)
bit  10      AVAIL2  (not payload)
bits 11-63   payload high (53 bits)

Do note that SHARED is not accounted for here, because that bit is only ever set on PRESENT entries

PTE_TAGGED_TYPE_MASK

Section titled “PTE_TAGGED_TYPE_MASK”
#define PTE_TAGGED_TYPE_MASK 0x3ULL
source

PTE_TAGGED_PAYLOAD_LOW_BITS

Section titled “PTE_TAGGED_PAYLOAD_LOW_BITS”
#define PTE_TAGGED_PAYLOAD_LOW_BITS 6
source

PTE_TAGGED_PAYLOAD_LOW_SHIFT

Section titled “PTE_TAGGED_PAYLOAD_LOW_SHIFT”
#define PTE_TAGGED_PAYLOAD_LOW_SHIFT 3
source

packed position of the low chunk

PTE_TAGGED_PAYLOAD_HIGH_SHIFT

Section titled “PTE_TAGGED_PAYLOAD_HIGH_SHIFT”
#define PTE_TAGGED_PAYLOAD_HIGH_SHIFT
source
Expansion
#define PTE_TAGGED_PAYLOAD_HIGH_SHIFT \
    11 /* packed position of the high chunk \
        */

PTE_TAGGED_PAYLOAD_LOW_MASK

Section titled “PTE_TAGGED_PAYLOAD_LOW_MASK”
#define PTE_TAGGED_PAYLOAD_LOW_MASK (BIT(PTE_TAGGED_PAYLOAD_LOW_BITS) - 1)
source

PTE_TAGGED_PAYLOAD_BITS

Section titled “PTE_TAGGED_PAYLOAD_BITS”
#define PTE_TAGGED_PAYLOAD_BITS
source
Expansion
#define PTE_TAGGED_PAYLOAD_BITS \
    (PTE_TAGGED_PAYLOAD_LOW_BITS + (64 - PTE_TAGGED_PAYLOAD_HIGH_SHIFT))

PTE_TAGGED_GET_TYPE

Section titled “PTE_TAGGED_GET_TYPE”
#define PTE_TAGGED_GET_TYPE(pte)
source
Expansion
#define PTE_TAGGED_GET_TYPE(pte) \
    (((pte) >> PTE_TAGGED_TYPE_SHIFT) & PTE_TAGGED_TYPE_MASK)

PTE_TAGGED_SET_TYPE

Section titled “PTE_TAGGED_SET_TYPE”
#define PTE_TAGGED_SET_TYPE(type)
source
Expansion
#define PTE_TAGGED_SET_TYPE(type) ((uint64_t) (type) << PTE_TAGGED_TYPE_SHIFT)