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
|
#include <linux/kernel.h>
#include <asm/cputype.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
static void idmap_add_pmd(pgd_t *pgd, unsigned long addr, unsigned long end,
unsigned long prot)
{
pmd_t *pmd = pmd_offset(pgd, addr);
addr = (addr & PMD_MASK) | prot;
pmd[0] = __pmd(addr);
addr += SECTION_SIZE;
pmd[1] = __pmd(addr);
flush_pmd_entry(pmd);
}
void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
{
unsigned long prot, next;
prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;
if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
prot |= PMD_BIT4;
pgd += pgd_index(addr);
do {
next = pgd_addr_end(addr, end);
idmap_add_pmd(pgd, addr, next, prot);
} while (pgd++, addr = next, addr != end);
}
#ifdef CONFIG_SMP
static void idmap_del_pmd(pgd_t *pgd, unsigned long addr, unsigned long end)
{
pmd_t *pmd = pmd_offset(pgd, addr);
pmd_clear(pmd);
}
void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end)
{
unsigned long next;
pgd += pgd_index(addr);
do {
next = pgd_addr_end(addr, end);
idmap_del_pmd(pgd, addr, next);
} while (pgd++, addr = next, addr != end);
}
#endif
/*
* In order to soft-boot, we need to insert a 1:1 mapping in place of
* the user-mode pages. This will then ensure that we have predictable
* results when turning the mmu off
*/
void setup_mm_for_reboot(char mode)
{
/*
* We need to access to user-mode page tables here. For kernel threads
* we don't have any user-mode mappings so we use the context that we
* "borrowed".
*/
identity_mapping_add(current->active_mm->pgd, 0, TASK_SIZE);
local_flush_tlb_all();
}
|
