1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2005-2017 Andes Technology Corporation
4 #include <linux/init_task.h>
5 #include <asm/pgalloc.h>
7 #define FIRST_KERNEL_PGD_NR (USER_PTRS_PER_PGD)
10 * need to get a page for level 1
13 pgd_t *pgd_alloc(struct mm_struct *mm)
15 pgd_t *new_pgd, *init_pgd;
18 new_pgd = (pgd_t *) __get_free_pages(GFP_KERNEL, 0);
21 for (i = 0; i < PTRS_PER_PGD; i++) {
25 new_pgd -= PTRS_PER_PGD;
27 init_pgd = pgd_offset_k(0);
29 memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
30 (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
32 cpu_dcache_wb_range((unsigned long)new_pgd,
33 (unsigned long)new_pgd +
34 PTRS_PER_PGD * sizeof(pgd_t));
35 inc_zone_page_state(virt_to_page((unsigned long *)new_pgd),
41 void pgd_free(struct mm_struct *mm, pgd_t * pgd)
60 dec_zone_page_state(virt_to_page((unsigned long *)pgd), NR_PAGETABLE);
65 free_pages((unsigned long)pgd, 0);
69 * In order to soft-boot, we need to insert a 1:1 mapping in place of
70 * the user-mode pages. This will then ensure that we have predictable
71 * results when turning the mmu off
73 void setup_mm_for_reboot(char mode)
80 if (current->mm && current->mm->pgd)
81 pgd = current->mm->pgd;
85 for (i = 0; i < USER_PTRS_PER_PGD; i++) {
86 pmdval = (i << PGDIR_SHIFT);
87 pmd = pmd_offset(pgd + i, i << PGDIR_SHIFT);
88 set_pmd(pmd, __pmd(pmdval));