1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
// SPDX-License-Identifier: GPL-2.0
/*
* Helper routines for building identity mapping page tables. This is
* included by both the compressed kernel and the regular kernel.
*/
static void free_pte(struct x86_mapping_info *info, pmd_t *pmd)
{
pte_t *pte = pte_offset_kernel(pmd, 0);
info->free_pgt_page(pte, info->context);
}
static void free_pmd(struct x86_mapping_info *info, pud_t *pud)
{
pmd_t *pmd = pmd_offset(pud, 0);
int i;
for (i = 0; i < PTRS_PER_PMD; i++) {
if (!pmd_present(pmd[i]))
continue;
if (pmd_leaf(pmd[i]))
continue;
free_pte(info, &pmd[i]);
}
info->free_pgt_page(pmd, info->context);
}
static void free_pud(struct x86_mapping_info *info, p4d_t *p4d)
{
pud_t *pud = pud_offset(p4d, 0);
int i;
for (i = 0; i < PTRS_PER_PUD; i++) {
if (!pud_present(pud[i]))
continue;
if (pud_leaf(pud[i]))
continue;
free_pmd(info, &pud[i]);
}
info->free_pgt_page(pud, info->context);
}
static void free_p4d(struct x86_mapping_info *info, pgd_t *pgd)
{
p4d_t *p4d = p4d_offset(pgd, 0);
int i;
for (i = 0; i < PTRS_PER_P4D; i++) {
if (!p4d_present(p4d[i]))
continue;
free_pud(info, &p4d[i]);
}
if (pgtable_l5_enabled())
info->free_pgt_page(p4d, info->context);
}
void kernel_ident_mapping_free(struct x86_mapping_info *info, pgd_t *pgd)
{
int i;
for (i = 0; i < PTRS_PER_PGD; i++) {
if (!pgd_present(pgd[i]))
continue;
free_p4d(info, &pgd[i]);
}
info->free_pgt_page(pgd, info->context);
}
static void ident_pmd_init(struct x86_mapping_info *info, pmd_t *pmd_page,
unsigned long addr, unsigned long end)
{
addr &= PMD_MASK;
for (; addr < end; addr += PMD_SIZE) {
pmd_t *pmd = pmd_page + pmd_index(addr);
if (pmd_present(*pmd))
continue;
set_pmd(pmd, __pmd((addr - info->offset) | info->page_flag));
}
}
static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
unsigned long addr, unsigned long end)
{
unsigned long next;
for (; addr < end; addr = next) {
pud_t *pud = pud_page + pud_index(addr);
pmd_t *pmd;
bool use_gbpage;
next = (addr & PUD_MASK) + PUD_SIZE;
if (next > end)
next = end;
/* if this is already a gbpage, this portion is already mapped */
if (pud_leaf(*pud))
continue;
/* Is using a gbpage allowed? */
use_gbpage = info->direct_gbpages;
/* Don't use gbpage if it maps more than the requested region. */
/* at the begining: */
use_gbpage &= ((addr & ~PUD_MASK) == 0);
/* ... or at the end: */
use_gbpage &= ((next & ~PUD_MASK) == 0);
/* Never overwrite existing mappings */
use_gbpage &= !pud_present(*pud);
if (use_gbpage) {
pud_t pudval;
pudval = __pud((addr - info->offset) | info->page_flag);
set_pud(pud, pudval);
continue;
}
if (pud_present(*pud)) {
pmd = pmd_offset(pud, 0);
ident_pmd_init(info, pmd, addr, next);
continue;
}
pmd = (pmd_t *)info->alloc_pgt_page(info->context);
if (!pmd)
return -ENOMEM;
ident_pmd_init(info, pmd, addr, next);
set_pud(pud, __pud(__pa(pmd) | info->kernpg_flag));
}
return 0;
}
static int ident_p4d_init(struct x86_mapping_info *info, p4d_t *p4d_page,
unsigned long addr, unsigned long end)
{
unsigned long next;
int result;
for (; addr < end; addr = next) {
p4d_t *p4d = p4d_page + p4d_index(addr);
pud_t *pud;
next = (addr & P4D_MASK) + P4D_SIZE;
if (next > end)
next = end;
if (p4d_present(*p4d)) {
pud = pud_offset(p4d, 0);
result = ident_pud_init(info, pud, addr, next);
if (result)
return result;
continue;
}
pud = (pud_t *)info->alloc_pgt_page(info->context);
if (!pud)
return -ENOMEM;
result = ident_pud_init(info, pud, addr, next);
if (result)
return result;
set_p4d(p4d, __p4d(__pa(pud) | info->kernpg_flag));
}
return 0;
}
int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
unsigned long pstart, unsigned long pend)
{
unsigned long addr = pstart + info->offset;
unsigned long end = pend + info->offset;
unsigned long next;
int result;
/* Set the default pagetable flags if not supplied */
if (!info->kernpg_flag)
info->kernpg_flag = _KERNPG_TABLE;
/* Filter out unsupported __PAGE_KERNEL_* bits: */
info->kernpg_flag &= __default_kernel_pte_mask;
for (; addr < end; addr = next) {
pgd_t *pgd = pgd_page + pgd_index(addr);
p4d_t *p4d;
next = (addr & PGDIR_MASK) + PGDIR_SIZE;
if (next > end)
next = end;
if (pgd_present(*pgd)) {
p4d = p4d_offset(pgd, 0);
result = ident_p4d_init(info, p4d, addr, next);
if (result)
return result;
continue;
}
p4d = (p4d_t *)info->alloc_pgt_page(info->context);
if (!p4d)
return -ENOMEM;
result = ident_p4d_init(info, p4d, addr, next);
if (result)
return result;
if (pgtable_l5_enabled()) {
set_pgd(pgd, __pgd(__pa(p4d) | info->kernpg_flag));
} else {
/*
* With p4d folded, pgd is equal to p4d.
* The pgd entry has to point to the pud page table in this case.
*/
pud_t *pud = pud_offset(p4d, 0);
set_pgd(pgd, __pgd(__pa(pud) | info->kernpg_flag));
}
}
return 0;
}
|
