1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/arch/arm/mm/pgd.c
5 * Copyright (C) 1998-2005 Russell King
9 #include <linux/highmem.h>
10 #include <linux/slab.h>
13 #include <asm/pgalloc.h>
15 #include <asm/tlbflush.h>
19 #ifdef CONFIG_ARM_LPAE
20 #define __pgd_alloc() kmalloc_array(PTRS_PER_PGD, sizeof(pgd_t), GFP_KERNEL)
21 #define __pgd_free(pgd) kfree(pgd)
23 #define __pgd_alloc() (pgd_t *)__get_free_pages(GFP_KERNEL, 2)
24 #define __pgd_free(pgd) free_pages((unsigned long)pgd, 2)
28 * need to get a 16k page for level 1
30 pgd_t *pgd_alloc(struct mm_struct *mm)
32 pgd_t *new_pgd, *init_pgd;
33 p4d_t *new_p4d, *init_p4d;
34 pud_t *new_pud, *init_pud;
35 pmd_t *new_pmd, *init_pmd;
36 pte_t *new_pte, *init_pte;
38 new_pgd = __pgd_alloc();
42 memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
45 * Copy over the kernel and IO PGD entries
47 init_pgd = pgd_offset_k(0);
48 memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
49 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
51 clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
53 #ifdef CONFIG_ARM_LPAE
55 * Allocate PMD table for modules and pkmap mappings.
57 new_p4d = p4d_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
62 new_pud = pud_alloc(mm, new_p4d, MODULES_VADDR);
66 new_pmd = pmd_alloc(mm, new_pud, 0);
71 * Copy PMD table for KASAN shadow mappings.
73 init_pgd = pgd_offset_k(TASK_SIZE);
74 init_p4d = p4d_offset(init_pgd, TASK_SIZE);
75 init_pud = pud_offset(init_p4d, TASK_SIZE);
76 init_pmd = pmd_offset(init_pud, TASK_SIZE);
77 new_pmd = pmd_offset(new_pud, TASK_SIZE);
78 memcpy(new_pmd, init_pmd,
79 (pmd_index(MODULES_VADDR) - pmd_index(TASK_SIZE))
81 clean_dcache_area(new_pmd, PTRS_PER_PMD * sizeof(pmd_t));
82 #endif /* CONFIG_KASAN */
83 #endif /* CONFIG_LPAE */
85 if (!vectors_high()) {
87 * On ARM, first page must always be allocated since it
88 * contains the machine vectors. The vectors are always high
91 new_p4d = p4d_alloc(mm, new_pgd, 0);
95 new_pud = pud_alloc(mm, new_p4d, 0);
99 new_pmd = pmd_alloc(mm, new_pud, 0);
103 new_pte = pte_alloc_map(mm, new_pmd, 0);
107 #ifndef CONFIG_ARM_LPAE
109 * Modify the PTE pointer to have the correct domain. This
110 * needs to be the vectors domain to avoid the low vectors
113 pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK;
114 pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);
117 init_p4d = p4d_offset(init_pgd, 0);
118 init_pud = pud_offset(init_p4d, 0);
119 init_pmd = pmd_offset(init_pud, 0);
120 init_pte = pte_offset_map(init_pmd, 0);
121 set_pte_ext(new_pte + 0, init_pte[0], 0);
122 set_pte_ext(new_pte + 1, init_pte[1], 0);
130 pmd_free(mm, new_pmd);
133 pud_free(mm, new_pud);
135 p4d_free(mm, new_p4d);
142 void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
153 pgd = pgd_base + pgd_index(0);
154 if (pgd_none_or_clear_bad(pgd))
157 p4d = p4d_offset(pgd, 0);
158 if (p4d_none_or_clear_bad(p4d))
161 pud = pud_offset(p4d, 0);
162 if (pud_none_or_clear_bad(pud))
165 pmd = pmd_offset(pud, 0);
166 if (pmd_none_or_clear_bad(pmd))
169 pte = pmd_pgtable(*pmd);
184 #ifdef CONFIG_ARM_LPAE
186 * Free modules/pkmap or identity pmd tables.
188 for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) {
189 if (pgd_none_or_clear_bad(pgd))
191 if (pgd_val(*pgd) & L_PGD_SWAPPER)
193 p4d = p4d_offset(pgd, 0);
194 if (p4d_none_or_clear_bad(p4d))
196 pud = pud_offset(p4d, 0);
197 if (pud_none_or_clear_bad(pud))
199 pmd = pmd_offset(pud, 0);
210 __pgd_free(pgd_base);