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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2019 SiFive
*/
#include <linux/pagewalk.h>
#include <linux/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/bitops.h>
struct pageattr_masks {
pgprot_t set_mask;
pgprot_t clear_mask;
};
static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)
{
struct pageattr_masks *masks = walk->private;
unsigned long new_val = val;
new_val &= ~(pgprot_val(masks->clear_mask));
new_val |= (pgprot_val(masks->set_mask));
return new_val;
}
static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
pgd_t val = READ_ONCE(*pgd);
if (pgd_leaf(val)) {
val = __pgd(set_pageattr_masks(pgd_val(val), walk));
set_pgd(pgd, val);
}
return 0;
}
static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
p4d_t val = READ_ONCE(*p4d);
if (p4d_leaf(val)) {
val = __p4d(set_pageattr_masks(p4d_val(val), walk));
set_p4d(p4d, val);
}
return 0;
}
static int pageattr_pud_entry(pud_t *pud, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
pud_t val = READ_ONCE(*pud);
if (pud_leaf(val)) {
val = __pud(set_pageattr_masks(pud_val(val), walk));
set_pud(pud, val);
}
return 0;
}
static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
pmd_t val = READ_ONCE(*pmd);
if (pmd_leaf(val)) {
val = __pmd(set_pageattr_masks(pmd_val(val), walk));
set_pmd(pmd, val);
}
return 0;
}
static int pageattr_pte_entry(pte_t *pte, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
pte_t val = READ_ONCE(*pte);
val = __pte(set_pageattr_masks(pte_val(val), walk));
set_pte(pte, val);
return 0;
}
static int pageattr_pte_hole(unsigned long addr, unsigned long next,
int depth, struct mm_walk *walk)
{
/* Nothing to do here */
return 0;
}
const static struct mm_walk_ops pageattr_ops = {
.pgd_entry = pageattr_pgd_entry,
.p4d_entry = pageattr_p4d_entry,
.pud_entry = pageattr_pud_entry,
.pmd_entry = pageattr_pmd_entry,
.pte_entry = pageattr_pte_entry,
.pte_hole = pageattr_pte_hole,
};
static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
pgprot_t clear_mask)
{
int ret;
unsigned long start = addr;
unsigned long end = start + PAGE_SIZE * numpages;
struct pageattr_masks masks = {
.set_mask = set_mask,
.clear_mask = clear_mask
};
if (!numpages)
return 0;
mmap_read_lock(&init_mm);
ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
&masks);
mmap_read_unlock(&init_mm);
flush_tlb_kernel_range(start, end);
return ret;
}
int set_memory_ro(unsigned long addr, int numpages)
{
return __set_memory(addr, numpages, __pgprot(_PAGE_READ),
__pgprot(_PAGE_WRITE));
}
int set_memory_rw(unsigned long addr, int numpages)
{
return __set_memory(addr, numpages, __pgprot(_PAGE_READ | _PAGE_WRITE),
__pgprot(0));
}
int set_memory_x(unsigned long addr, int numpages)
{
return __set_memory(addr, numpages, __pgprot(_PAGE_EXEC), __pgprot(0));
}
int set_memory_nx(unsigned long addr, int numpages)
{
return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_EXEC));
}
int set_direct_map_invalid_noflush(struct page *page)
{
unsigned long start = (unsigned long)page_address(page);
unsigned long end = start + PAGE_SIZE;
struct pageattr_masks masks = {
.set_mask = __pgprot(0),
.clear_mask = __pgprot(_PAGE_PRESENT)
};
return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
}
int set_direct_map_default_noflush(struct page *page)
{
unsigned long start = (unsigned long)page_address(page);
unsigned long end = start + PAGE_SIZE;
struct pageattr_masks masks = {
.set_mask = PAGE_KERNEL,
.clear_mask = __pgprot(0)
};
return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
}
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (!debug_pagealloc_enabled())
return;
if (enable)
__set_memory((unsigned long)page_address(page), numpages,
__pgprot(_PAGE_PRESENT), __pgprot(0));
else
__set_memory((unsigned long)page_address(page), numpages,
__pgprot(0), __pgprot(_PAGE_PRESENT));
}
|
