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 pud_t *new_pud, *init_pud;
34 pmd_t *new_pmd, *init_pmd;
35 pte_t *new_pte, *init_pte;
37 new_pgd = __pgd_alloc();
41 memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
44 * Copy over the kernel and IO PGD entries
46 init_pgd = pgd_offset_k(0);
47 memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
48 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
50 clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
52 #ifdef CONFIG_ARM_LPAE
54 * Allocate PMD table for modules and pkmap mappings.
56 new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
61 new_pmd = pmd_alloc(mm, new_pud, 0);
66 if (!vectors_high()) {
68 * On ARM, first page must always be allocated since it
69 * contains the machine vectors. The vectors are always high
72 new_pud = pud_alloc(mm, new_pgd, 0);
76 new_pmd = pmd_alloc(mm, new_pud, 0);
80 new_pte = pte_alloc_map(mm, new_pmd, 0);
84 #ifndef CONFIG_ARM_LPAE
86 * Modify the PTE pointer to have the correct domain. This
87 * needs to be the vectors domain to avoid the low vectors
90 pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK;
91 pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);
94 init_pud = pud_offset(init_pgd, 0);
95 init_pmd = pmd_offset(init_pud, 0);
96 init_pte = pte_offset_map(init_pmd, 0);
97 set_pte_ext(new_pte + 0, init_pte[0], 0);
98 set_pte_ext(new_pte + 1, init_pte[1], 0);
106 pmd_free(mm, new_pmd);
109 pud_free(mm, new_pud);
116 void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
126 pgd = pgd_base + pgd_index(0);
127 if (pgd_none_or_clear_bad(pgd))
130 pud = pud_offset(pgd, 0);
131 if (pud_none_or_clear_bad(pud))
134 pmd = pmd_offset(pud, 0);
135 if (pmd_none_or_clear_bad(pmd))
138 pte = pmd_pgtable(*pmd);
150 #ifdef CONFIG_ARM_LPAE
152 * Free modules/pkmap or identity pmd tables.
154 for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) {
155 if (pgd_none_or_clear_bad(pgd))
157 if (pgd_val(*pgd) & L_PGD_SWAPPER)
159 pud = pud_offset(pgd, 0);
160 if (pud_none_or_clear_bad(pud))
162 pmd = pmd_offset(pud, 0);
170 __pgd_free(pgd_base);