blob: 2ade20d8eab3965d749e2c44d475cc931b52a3c3 [file] [log] [blame]
GuanXuetao56372b02011-01-15 18:17:56 +08001/*
2 * linux/arch/unicore32/mm/pgd.c
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/mm.h>
13#include <linux/gfp.h>
14#include <linux/highmem.h>
15
16#include <asm/pgalloc.h>
17#include <asm/page.h>
18#include <asm/tlbflush.h>
19
20#include "mm.h"
21
22#define FIRST_KERNEL_PGD_NR (FIRST_USER_PGD_NR + USER_PTRS_PER_PGD)
23
24/*
25 * need to get a 4k page for level 1
26 */
27pgd_t *get_pgd_slow(struct mm_struct *mm)
28{
29 pgd_t *new_pgd, *init_pgd;
30 pmd_t *new_pmd, *init_pmd;
31 pte_t *new_pte, *init_pte;
32
33 new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 0);
34 if (!new_pgd)
35 goto no_pgd;
36
37 memset(new_pgd, 0, FIRST_KERNEL_PGD_NR * sizeof(pgd_t));
38
39 /*
40 * Copy over the kernel and IO PGD entries
41 */
42 init_pgd = pgd_offset_k(0);
43 memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
44 (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
45
46 clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
47
48 if (!vectors_high()) {
49 /*
50 * On UniCore, first page must always be allocated since it
51 * contains the machine vectors.
52 */
53 new_pmd = pmd_alloc(mm, (pud_t *)new_pgd, 0);
54 if (!new_pmd)
55 goto no_pmd;
56
GuanXuetao4ef2ec62011-02-22 17:34:47 +080057 new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
GuanXuetao56372b02011-01-15 18:17:56 +080058 if (!new_pte)
59 goto no_pte;
60
61 init_pmd = pmd_offset((pud_t *)init_pgd, 0);
62 init_pte = pte_offset_map(init_pmd, 0);
63 set_pte(new_pte, *init_pte);
64 pte_unmap(init_pte);
65 pte_unmap(new_pte);
66 }
67
68 return new_pgd;
69
70no_pte:
71 pmd_free(mm, new_pmd);
Kirill A. Shutemovb30fe6c2015-02-11 15:26:53 -080072 mm_dec_nr_pmds(mm);
GuanXuetao56372b02011-01-15 18:17:56 +080073no_pmd:
74 free_pages((unsigned long)new_pgd, 0);
75no_pgd:
76 return NULL;
77}
78
79void free_pgd_slow(struct mm_struct *mm, pgd_t *pgd)
80{
81 pmd_t *pmd;
82 pgtable_t pte;
83
84 if (!pgd)
85 return;
86
87 /* pgd is always present and good */
88 pmd = pmd_off(pgd, 0);
89 if (pmd_none(*pmd))
90 goto free;
91 if (pmd_bad(*pmd)) {
92 pmd_ERROR(*pmd);
93 pmd_clear(pmd);
94 goto free;
95 }
96
97 pte = pmd_pgtable(*pmd);
98 pmd_clear(pmd);
99 pte_free(mm, pte);
Kirill A. Shutemovb30fe6c2015-02-11 15:26:53 -0800100 atomic_long_dec(&mm->nr_ptes);
GuanXuetao56372b02011-01-15 18:17:56 +0800101 pmd_free(mm, pmd);
Kirill A. Shutemovb30fe6c2015-02-11 15:26:53 -0800102 mm_dec_nr_pmds(mm);
GuanXuetao56372b02011-01-15 18:17:56 +0800103free:
104 free_pages((unsigned long) pgd, 0);
105}