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-or-later
/*
* This file contains the routines setting up the linux page tables.
* -- paulus
*
* Derived from arch/ppc/mm/init.c:
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>
#include <linux/set_memory.h>
#include <asm/pgalloc.h>
#include <asm/fixmap.h>
#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/early_ioremap.h>
#include <mm/mmu_decl.h>
static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data;
notrace void __init early_ioremap_init(void)
{
unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE);
pte_t *ptep = (pte_t *)early_fixmap_pagetable;
pmd_t *pmdp = pmd_off_k(addr);
for (; (s32)(FIXADDR_TOP - addr) > 0;
addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++)
pmd_populate_kernel(&init_mm, pmdp, ptep);
early_ioremap_setup();
}
static void __init *early_alloc_pgtable(unsigned long size)
{
void *ptr = memblock_alloc(size, size);
if (!ptr)
panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
__func__, size, size);
return ptr;
}
pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va)
{
if (pmd_none(*pmdp)) {
pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
return pte_offset_kernel(pmdp, va);
}
int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
{
pmd_t *pd;
pte_t *pg;
int err = -ENOMEM;
/* Use upper 10 bits of VA to index the first level map */
pd = pmd_off_k(va);
/* Use middle 10 bits of VA to index the second-level map */
if (likely(slab_is_available()))
pg = pte_alloc_kernel(pd, va);
else
pg = early_pte_alloc_kernel(pd, va);
if (pg) {
err = 0;
/* The PTE should never be already set nor present in the
* hash table
*/
BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot));
set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
}
smp_wmb();
return err;
}
/*
* Map in a chunk of physical memory starting at start.
*/
static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
{
unsigned long v, s;
phys_addr_t p;
bool ktext;
s = offset;
v = PAGE_OFFSET + s;
p = memstart_addr + s;
for (; s < top; s += PAGE_SIZE) {
ktext = core_kernel_text(v);
map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
v += PAGE_SIZE;
p += PAGE_SIZE;
}
}
void __init mapin_ram(void)
{
phys_addr_t base, end;
u64 i;
for_each_mem_range(i, &base, &end) {
phys_addr_t top = min(end, total_lowmem);
if (base >= top)
continue;
base = mmu_mapin_ram(base, top);
__mapin_ram_chunk(base, top);
}
}
void mark_initmem_nx(void)
{
unsigned long numpages = PFN_UP((unsigned long)_einittext) -
PFN_DOWN((unsigned long)_sinittext);
mmu_mark_initmem_nx();
if (!v_block_mapped((unsigned long)_sinittext)) {
set_memory_nx((unsigned long)_sinittext, numpages);
set_memory_rw((unsigned long)_sinittext, numpages);
}
}
#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void)
{
unsigned long numpages;
if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX) && mmu_has_feature(MMU_FTR_HPTE_TABLE))
pr_warn("This platform has HASH MMU, STRICT_MODULE_RWX won't work\n");
if (v_block_mapped((unsigned long)_stext + 1)) {
mmu_mark_rodata_ro();
ptdump_check_wx();
return;
}
/*
* mark .text and .rodata as read only. Use __init_begin rather than
* __end_rodata to cover NOTES and EXCEPTION_TABLE.
*/
numpages = PFN_UP((unsigned long)__init_begin) -
PFN_DOWN((unsigned long)_stext);
set_memory_ro((unsigned long)_stext, numpages);
// mark_initmem_nx() should have already run by now
ptdump_check_wx();
}
#endif
#if defined(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && defined(CONFIG_DEBUG_PAGEALLOC)
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
unsigned long addr = (unsigned long)page_address(page);
if (PageHighMem(page))
return;
if (enable)
set_memory_p(addr, numpages);
else
set_memory_np(addr, numpages);
}
#endif /* CONFIG_DEBUG_PAGEALLOC */
|
