1/* @title: Page */
2#pragma once
3#include <compiler/core.h>
4#include <global.h>
5#include <math/align.h>
6#include <math/bit.h>
7#include <math/units.h>
8#include <mem/hhdm.h>
9#include <stdint.h>
10#include <sync/spinlock.h>
11
12struct folio;
13
14#define PAGE_SIZE KIB(4)
15#define PAGE_2MB MIB(2)
16#define PAGE_1GB GIB(1)
17
18#define PAGE_PRESENT_SHIFT (0)
19#define PAGE_PRESENT (0x1UL)
20#define PAGE_WRITE (0x2UL)
21#define PAGE_USER_ALLOWED (0x4UL)
22#define PAGE_XD BIT(63) // E(x)ecute (D)isable
23#define PAGE_PHYS_MASK (0x00FFFFFFF000UL)
24#define PAGE_UNCACHABLE BIT(4) /* PCD */
25#define PAGE_NO_FLAGS (0)
26#define PAGE_WRITETHROUGH BIT(3)
27#define PAGE_HUGE BIT(7) /* PS: 2MB at the PD level, 1GB at the PDPT */
28
29/* TODO: */
30#define PAGE_PAGEABLE (0)
31#define PAGE_MOVABLE (0)
32
33#define PAGE_2MB_PHYS_MASK (0x00FFFFE00000UL)
34#define PAGE_1GB_PHYS_MASK (0x00FFC0000000UL)
35#define PAGE_ALIGN_DOWN(x) ALIGN_DOWN((uintptr_t) (x), PAGE_SIZE)
36#define PAGE_ALIGN_UP(x) ALIGN_UP((uintptr_t) (x), PAGE_SIZE)
37#define PAGE_ALIGN_UP_WRAPPING(x) ALIGN_UP_WRAPPING((uintptr_t) (x), PAGE_SIZE)
38#define IS_PAGE_ALIGNED(x) IS_ALIGNED((uintptr_t) (x), PAGE_SIZE)
39#define PAGE_2MB_ALIGN_DOWN(x) ALIGN_DOWN((uintptr_t) (x), PAGE_2MB)
40#define PAGE_2MB_ALIGN_UP(x) ALIGN_UP((uintptr_t) (x), PAGE_2MB)
41#define PAGE_1GB_ALIGN_DOWN(x) ALIGN_DOWN((uintptr_t) (x), PAGE_1GB)
42#define PAGE_1GB_ALIGN_UP(x) ALIGN_UP((uintptr_t) (x), PAGE_1GB)
43
44#define PAGE_TO_PFN(addr) ((addr) / PAGE_SIZE)
45#define PFN_TO_PAGE(pfn) ((pfn) * PAGE_SIZE)
46
47#define PAGES_NEEDED_FOR(bytes) DIV_ROUND_UP((bytes), PAGE_SIZE)
48
49#define VMM_MAP_BASE 0xFFFFA00000200000
50#define VMM_MAP_LIMIT 0xFFFFA00010000000
51#define PT_ENTRIES 512
52#define PT_INDEX_MASK 0x1FFULL
53
54#define PAGE_4K_SHIFT 12
55#define PAGE_2M_SHIFT 21
56#define PAGE_1G_SHIFT 30
57
58#define PAGE_TAG_MASK 0x7ULL
59#define PAGE_PAYLOAD_ALIGNMENT 8
60
61enum page_tag {
62 /* Low 3 bits */
63 PAGE_TAG_NONE = 0,
64 PAGE_TAG_BUDDY = 1,
65 PAGE_TAG_FOLIO = 2,
66 PAGE_TAG_ARENA = 3, /* cached as a free single page in a domain arena */
67};
68
69struct page {
70 uint64_t meta;
71};
72
73struct page_table {
74 pte_t entries[512];
75} cc_packed;
76static_assert(sizeof(struct page_table) == PAGE_SIZE);
77
78static inline enum page_tag page_get_tag(const struct page *p) {
79 return (enum page_tag)(p->meta & PAGE_TAG_MASK);
80}
81
82static inline void page_set_tag(struct page *p, enum page_tag tag) {
83 p->meta = (p->meta & ~PAGE_TAG_MASK) | (tag & PAGE_TAG_MASK);
84}
85
86static inline uint64_t page_get_payload(const struct page *p) {
87 return p->meta & ~PAGE_TAG_MASK;
88}
89
90static inline void page_set_payload(struct page *p, uint64_t payload) {
91 p->meta = (p->meta & PAGE_TAG_MASK) | (payload & ~PAGE_TAG_MASK);
92}
93
94static inline void page_assert_tag(const struct page *p,
95 enum page_tag expected) {
96 enforce(page_get_tag(p) == expected);
97}
98
99static inline struct page *page_for_pfn(pfn_t pfn) {
100 if (pfn >= global.last_pfn)
101 return NULL;
102
103 return &global.page_array[pfn];
104}
105
106static inline struct page *page_for_paddr(paddr_t paddr) {
107 return page_for_pfn(PAGE_TO_PFN(paddr));
108}
109
110static inline pfn_t page_get_pfn(const struct page *bp) {
111 return (pfn_t) (bp - global.page_array);
112}
113
114static inline paddr_t page_get_paddr(const struct page *bp) {
115 return PFN_TO_PAGE(page_get_pfn(bp));
116}
117
118static inline vaddr_t page_get_vaddr(const struct page *bp) {
119 return hhdm_paddr_to_vaddr(p: page_get_paddr(bp));
120}
121