tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Entries per page directory level. The PTE level must use a 64b record
3 * for each page table entry. The PMD and PGD level use a 32b record for
4 * each entry by assuming that each entry is page aligned.
5 */
6#define PTE_INDEX_SIZE 9
7#define PMD_INDEX_SIZE 7
8#define PUD_INDEX_SIZE 7
9#define PGD_INDEX_SIZE 9
10
11#define PTE_TABLE_SIZE (sizeof(pte_t) << PTE_INDEX_SIZE)
12#define PMD_TABLE_SIZE (sizeof(pmd_t) << PMD_INDEX_SIZE)
13#define PUD_TABLE_SIZE (sizeof(pud_t) << PUD_INDEX_SIZE)
14#define PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE)
15
16#define PTRS_PER_PTE (1 << PTE_INDEX_SIZE)
17#define PTRS_PER_PMD (1 << PMD_INDEX_SIZE)
18#define PTRS_PER_PUD (1 << PMD_INDEX_SIZE)
19#define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)
20
21/* PMD_SHIFT determines what a second-level page table entry can map */
22#define PMD_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
23#define PMD_SIZE (1UL << PMD_SHIFT)
24#define PMD_MASK (~(PMD_SIZE-1))
25
26/* With 4k base page size, hugepage PTEs go at the PMD level */
27#define MIN_HUGEPTE_SHIFT PMD_SHIFT
28
29/* PUD_SHIFT determines what a third-level page table entry can map */
30#define PUD_SHIFT (PMD_SHIFT + PMD_INDEX_SIZE)
31#define PUD_SIZE (1UL << PUD_SHIFT)
32#define PUD_MASK (~(PUD_SIZE-1))
33
34/* PGDIR_SHIFT determines what a fourth-level page table entry can map */
35#define PGDIR_SHIFT (PUD_SHIFT + PUD_INDEX_SIZE)
36#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
37#define PGDIR_MASK (~(PGDIR_SIZE-1))
38
39/* PTE bits */
40#define _PAGE_SECONDARY 0x8000 /* software: HPTE is in secondary group */
41#define _PAGE_GROUP_IX 0x7000 /* software: HPTE index within group */
42#define _PAGE_F_SECOND _PAGE_SECONDARY
43#define _PAGE_F_GIX _PAGE_GROUP_IX
44
45/* PTE flags to conserve for HPTE identification */
46#define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | \
47 _PAGE_SECONDARY | _PAGE_GROUP_IX)
48
49/* PAGE_MASK gives the right answer below, but only by accident */
50/* It should be preserving the high 48 bits and then specifically */
51/* preserving _PAGE_SECONDARY | _PAGE_GROUP_IX */
52#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | \
53 _PAGE_HPTEFLAGS)
54
55/* Bits to mask out from a PMD to get to the PTE page */
56#define PMD_MASKED_BITS 0
57/* Bits to mask out from a PUD to get to the PMD page */
58#define PUD_MASKED_BITS 0
59/* Bits to mask out from a PGD to get to the PUD page */
60#define PGD_MASKED_BITS 0
61
62/* shift to put page number into pte */
63#define PTE_RPN_SHIFT (17)
64
65#ifdef STRICT_MM_TYPECHECKS
66#define __real_pte(e,p) ((real_pte_t){(e)})
67#define __rpte_to_pte(r) ((r).pte)
68#else
69#define __real_pte(e,p) (e)
70#define __rpte_to_pte(r) (__pte(r))
71#endif
72#define __rpte_to_hidx(r,index) (pte_val(__rpte_to_pte(r)) >> 12)
73
74#define pte_iterate_hashed_subpages(rpte, psize, va, index, shift) \
75 do { \
76 index = 0; \
77 shift = mmu_psize_defs[psize].shift; \
78
79#define pte_iterate_hashed_end() } while(0)
80
81/*
82 * 4-level page tables related bits
83 */
84
85#define pgd_none(pgd) (!pgd_val(pgd))
86#define pgd_bad(pgd) (pgd_val(pgd) == 0)
87#define pgd_present(pgd) (pgd_val(pgd) != 0)
88#define pgd_clear(pgdp) (pgd_val(*(pgdp)) = 0)
89#define pgd_page(pgd) (pgd_val(pgd) & ~PGD_MASKED_BITS)
90
91#define pud_offset(pgdp, addr) \
92 (((pud_t *) pgd_page(*(pgdp))) + \
93 (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
94
95#define pud_ERROR(e) \
96 printk("%s:%d: bad pud %08lx.\n", __FILE__, __LINE__, pud_val(e))