Page Table

Structs

struct pte_tagged {
    enum pte_tag_type  type;
    uint64_t           payload;
};

enum pte_tag_type : uint8_t {
    PTE_TAG_TYPE_NONE = 0,
    PTE_TAG_TYPE_DEMAND_PAGED = 1,
};

typedef _Atomic uint64_t pte_atomic_t;

void pte_tagged_check(struct pte_tagged *pt);

uint64_t pte_tagged_pack(struct pte_tagged *pt);

struct pte_tagged pte_tagged_unpack(pte_t pte);

bool pte_locked(pte_atomic_t *pte);

uint64_t pte_read(pte_atomic_t *pte);

uint64_t pte_or(pte_atomic_t *pte, uint64_t val);

void pte_unlock_internal(pte_atomic_t *pte);

void pte_lock_internal(pte_atomic_t *pte);

enum irql pte_lock_irql(pte_atomic_t *pte);

void pte_unlock_irql(pte_atomic_t *pte, enum irql old_irql);

bool pte_has_tag(pte_atomic_t *pte);

uint64_t pte_tag_pte(pte_atomic_t *pte, struct pte_tagged *ptag);

struct pte_tagged pte_read_tag(pte_atomic_t *pte);

bool pte_in_use(pte_atomic_t *pte);

#define PT_LEVELS 4

#define PT_SHIFT_L1 12

#define PT_SHIFT_L2 21

#define PT_SHIFT_L3 30

#define PT_SHIFT_L4 39

#define PT_STRIDE 9

#define PTE_LOCK_SHIFT 9

#define PTE_AVAIL2_SHIFT 10

#define PTE_LOCK_BIT ((uint64_t) 1 << PTE_LOCK_SHIFT)

#define PTE_AVAIL2_BIT ((uint64_t) 1 << PTE_AVAIL2_SHIFT)

#define PTE_TAGGED_TYPE_SHIFT (PAGE_PRESENT_SHIFT + 1)

#define PTE_TAGGED_TYPE_MASK 0x3ULL

#define PTE_TAGGED_PAYLOAD_LOW_BITS 6

#define PTE_TAGGED_PAYLOAD_LOW_SHIFT 3 /* packed position of the low chunk */

#define PTE_TAGGED_PAYLOAD_HIGH_SHIFT \
    11 /* packed position of the high chunk \
        */

#define PTE_TAGGED_PAYLOAD_LOW_MASK ((1ULL << PTE_TAGGED_PAYLOAD_LOW_BITS) - 1)

#define PTE_TAGGED_PAYLOAD_BITS \
    (PTE_TAGGED_PAYLOAD_LOW_BITS + (64 - PTE_TAGGED_PAYLOAD_HIGH_SHIFT))

#define PTE_TAGGED_GET_TYPE(pte) \
    (((pte) >> PTE_TAGGED_TYPE_SHIFT) & PTE_TAGGED_TYPE_MASK)

#define PTE_TAGGED_SET_TYPE(type) ((uint64_t) (type) << PTE_TAGGED_TYPE_SHIFT)