1 /* SPDX-License-Identifier: GPL-2.0-only */
2 #ifndef _ASMARM64_PGTABLE_H_
3 #define _ASMARM64_PGTABLE_H_
4 /*
5 * Copyright (C) 2024, IBM Inc, Nicholas Piggin <npiggin@gmail.com>
6 *
7 * Derived from Linux kernel MMU code.
8 */
9 #include <alloc.h>
10 #include <alloc_page.h>
11 #include <asm/io.h>
12 #include <asm/setup.h>
13 #include <asm/page.h>
14 #include <asm/pgtable-hwdef.h>
15
16 #include <linux/compiler.h>
17
18 /*
19 * We can convert va <=> pa page table addresses with simple casts
20 * because we always allocate their pages with alloc_page(), and
21 * alloc_page() always returns identity mapped pages.
22 */
23 #define pgtable_va(x) ((void *)(unsigned long)(x))
24 #define pgtable_pa(x) ((unsigned long)(x))
25
26 #define pgd_none(pgd) (!pgd_val(pgd))
27 #define pud_none(pud) (!pud_val(pud))
28 #define pmd_none(pmd) (!pmd_val(pmd))
29 #define pte_none(pte) (!pte_val(pte))
30
31 #define pgd_valid(pgd) (pgd_val(pgd) & cpu_to_be64(_PAGE_VALID))
32 #define pud_valid(pud) (pud_val(pud) & cpu_to_be64(_PAGE_VALID))
33 #define pmd_valid(pmd) (pmd_val(pmd) & cpu_to_be64(_PAGE_VALID))
34 #define pte_valid(pte) (pte_val(pte) & cpu_to_be64(_PAGE_VALID))
35
36 #define pmd_huge(pmd) false
37
pgd_page_vaddr(pgd_t pgd)38 static inline pud_t *pgd_page_vaddr(pgd_t pgd)
39 {
40 return pgtable_va(be64_to_cpu(pgd_val(pgd)) & PHYS_MASK & ~0xfffULL);
41 }
42
pud_page_vaddr(pud_t pud)43 static inline pmd_t *pud_page_vaddr(pud_t pud)
44 {
45 return pgtable_va(be64_to_cpu(pud_val(pud)) & PHYS_MASK & ~0xfffULL);
46 }
47
pmd_page_vaddr(pmd_t pmd)48 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
49 {
50 return pgtable_va(be64_to_cpu(pmd_val(pmd)) & PHYS_MASK & ~0xfffULL);
51 }
52
53 #define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
54 #define pgd_offset(pt, addr) ((pt) + pgd_index(addr))
55 #define pud_index(addr) (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
56 #define pud_offset(pgd, addr) (pgd_page_vaddr(*(pgd)) + pud_index(addr))
57 #define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
58 #define pmd_offset(pud, addr) (pud_page_vaddr(*(pud)) + pmd_index(addr))
59 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
60 #define pte_offset(pmd, addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr))
61
62 #define pgd_free(pgd) free(pgd)
pgd_alloc_one(void)63 static inline pgd_t *pgd_alloc_one(void)
64 {
65 size_t sz = PTRS_PER_PGD * sizeof(pgd_t);
66 pgd_t *pgd = memalign_pages(sz, sz);
67 memset(pgd, 0, sz);
68 return pgd;
69 }
70
71 #define pud_free(pud) free(pud)
pud_alloc_one(void)72 static inline pud_t *pud_alloc_one(void)
73 {
74 size_t sz = PTRS_PER_PGD * sizeof(pud_t);
75 pud_t *pud = memalign_pages(sz, sz);
76 memset(pud, 0, sz);
77 return pud;
78 }
pud_alloc(pgd_t * pgd,unsigned long addr)79 static inline pud_t *pud_alloc(pgd_t *pgd, unsigned long addr)
80 {
81 if (pgd_none(*pgd)) {
82 pgd_t entry;
83 pgd_val(entry) = cpu_to_be64(pgtable_pa(pud_alloc_one()) | _PAGE_VALID | (12 - 3) /* 4k pud page */);
84 WRITE_ONCE(*pgd, entry);
85 }
86 return pud_offset(pgd, addr);
87 }
88
89 #define pmd_free(pmd) free(pmd)
pmd_alloc_one(void)90 static inline pmd_t *pmd_alloc_one(void)
91 {
92 size_t sz = PTRS_PER_PMD * sizeof(pmd_t);
93 pmd_t *pmd = memalign_pages(sz, sz);
94 memset(pmd, 0, sz);
95 return pmd;
96 }
pmd_alloc(pud_t * pud,unsigned long addr)97 static inline pmd_t *pmd_alloc(pud_t *pud, unsigned long addr)
98 {
99 if (pud_none(*pud)) {
100 pud_t entry;
101 pud_val(entry) = cpu_to_be64(pgtable_pa(pmd_alloc_one()) | _PAGE_VALID | (12 - 3) /* 4k pmd page */);
102 WRITE_ONCE(*pud, entry);
103 }
104 return pmd_offset(pud, addr);
105 }
106
107 #define pte_free(pte) free(pte)
pte_alloc_one(void)108 static inline pte_t *pte_alloc_one(void)
109 {
110 size_t sz = PTRS_PER_PTE * sizeof(pte_t);
111 pte_t *pte = memalign_pages(sz, sz);
112 memset(pte, 0, sz);
113 return pte;
114 }
pte_alloc(pmd_t * pmd,unsigned long addr)115 static inline pte_t *pte_alloc(pmd_t *pmd, unsigned long addr)
116 {
117 if (pmd_none(*pmd)) {
118 pmd_t entry;
119 pmd_val(entry) = cpu_to_be64(pgtable_pa(pte_alloc_one()) | _PAGE_VALID | (21 - PAGE_SHIFT) /* 4k/256B pte page */);
120 WRITE_ONCE(*pmd, entry);
121 }
122 return pte_offset(pmd, addr);
123 }
124
125 #endif /* _ASMPPC64_PGTABLE_H_ */
126