1#include <linux/kernel.h>
 2
 3#include <asm/cputype.h>
 
 4#include <asm/pgalloc.h>
 5#include <asm/pgtable.h>
 
 
 6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 7static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
 8	unsigned long prot)
 9{
10	pmd_t *pmd = pmd_offset(pud, addr);
11
12	addr = (addr & PMD_MASK) | prot;
13	pmd[0] = __pmd(addr);
14	addr += SECTION_SIZE;
15	pmd[1] = __pmd(addr);
16	flush_pmd_entry(pmd);
17}
 
18
19static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
20	unsigned long prot)
21{
22	pud_t *pud = pud_offset(pgd, addr);
23	unsigned long next;
24
25	do {
26		next = pud_addr_end(addr, end);
27		idmap_add_pmd(pud, addr, next, prot);
28	} while (pud++, addr = next, addr != end);
29}
30
31void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
32{
33	unsigned long prot, next;
34
35	prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;
36	if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
37		prot |= PMD_BIT4;
38
39	pgd += pgd_index(addr);
40	do {
41		next = pgd_addr_end(addr, end);
42		idmap_add_pud(pgd, addr, next, prot);
43	} while (pgd++, addr = next, addr != end);
44}
45
46#ifdef CONFIG_SMP
47static void idmap_del_pmd(pud_t *pud, unsigned long addr, unsigned long end)
48{
49	pmd_t *pmd = pmd_offset(pud, addr);
50	pmd_clear(pmd);
51}
52
53static void idmap_del_pud(pgd_t *pgd, unsigned long addr, unsigned long end)
54{
55	pud_t *pud = pud_offset(pgd, addr);
56	unsigned long next;
57
58	do {
59		next = pud_addr_end(addr, end);
60		idmap_del_pmd(pud, addr, next);
61	} while (pud++, addr = next, addr != end);
62}
63
64void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end)
65{
66	unsigned long next;
67
68	pgd += pgd_index(addr);
69	do {
70		next = pgd_addr_end(addr, end);
71		idmap_del_pud(pgd, addr, next);
72	} while (pgd++, addr = next, addr != end);
73}
74#endif
75
76/*
77 * In order to soft-boot, we need to insert a 1:1 mapping in place of
78 * the user-mode pages.  This will then ensure that we have predictable
79 * results when turning the mmu off
80 */
81void setup_mm_for_reboot(char mode)
82{
83	/*
84	 * We need to access to user-mode page tables here. For kernel threads
85	 * we don't have any user-mode mappings so we use the context that we
86	 * "borrowed".
87	 */
88	identity_mapping_add(current->active_mm->pgd, 0, TASK_SIZE);
 
89	local_flush_tlb_all();
90}

  1#include <linux/kernel.h>
  2
  3#include <asm/cputype.h>
  4#include <asm/idmap.h>
  5#include <asm/pgalloc.h>
  6#include <asm/pgtable.h>
  7#include <asm/sections.h>
  8#include <asm/system_info.h>
  9
 10pgd_t *idmap_pgd;
 11
 12#ifdef CONFIG_ARM_LPAE
 13static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
 14	unsigned long prot)
 15{
 16	pmd_t *pmd;
 17	unsigned long next;
 18
 19	if (pud_none_or_clear_bad(pud) || (pud_val(*pud) & L_PGD_SWAPPER)) {
 20		pmd = pmd_alloc_one(&init_mm, addr);
 21		if (!pmd) {
 22			pr_warning("Failed to allocate identity pmd.\n");
 23			return;
 24		}
 25		pud_populate(&init_mm, pud, pmd);
 26		pmd += pmd_index(addr);
 27	} else
 28		pmd = pmd_offset(pud, addr);
 29
 30	do {
 31		next = pmd_addr_end(addr, end);
 32		*pmd = __pmd((addr & PMD_MASK) | prot);
 33		flush_pmd_entry(pmd);
 34	} while (pmd++, addr = next, addr != end);
 35}
 36#else	/* !CONFIG_ARM_LPAE */
 37static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
 38	unsigned long prot)
 39{
 40	pmd_t *pmd = pmd_offset(pud, addr);
 41
 42	addr = (addr & PMD_MASK) | prot;
 43	pmd[0] = __pmd(addr);
 44	addr += SECTION_SIZE;
 45	pmd[1] = __pmd(addr);
 46	flush_pmd_entry(pmd);
 47}
 48#endif	/* CONFIG_ARM_LPAE */
 49
 50static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
 51	unsigned long prot)
 52{
 53	pud_t *pud = pud_offset(pgd, addr);
 54	unsigned long next;
 55
 56	do {
 57		next = pud_addr_end(addr, end);
 58		idmap_add_pmd(pud, addr, next, prot);
 59	} while (pud++, addr = next, addr != end);
 60}
 61
 62static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
 63{
 64	unsigned long prot, next;
 65
 66	prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF;
 67	if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
 68		prot |= PMD_BIT4;
 69
 70	pgd += pgd_index(addr);
 71	do {
 72		next = pgd_addr_end(addr, end);
 73		idmap_add_pud(pgd, addr, next, prot);
 74	} while (pgd++, addr = next, addr != end);
 75}
 76
 77extern char  __idmap_text_start[], __idmap_text_end[];
 
 
 
 
 
 78
 79static int __init init_static_idmap(void)
 80{
 81	phys_addr_t idmap_start, idmap_end;
 
 82
 83	idmap_pgd = pgd_alloc(&init_mm);
 84	if (!idmap_pgd)
 85		return -ENOMEM;
 
 
 86
 87	/* Add an identity mapping for the physical address of the section. */
 88	idmap_start = virt_to_phys((void *)__idmap_text_start);
 89	idmap_end = virt_to_phys((void *)__idmap_text_end);
 90
 91	pr_info("Setting up static identity map for 0x%llx - 0x%llx\n",
 92		(long long)idmap_start, (long long)idmap_end);
 93	identity_mapping_add(idmap_pgd, idmap_start, idmap_end);
 94
 95	return 0;
 96}
 97early_initcall(init_static_idmap);
 98
 99/*
100 * In order to soft-boot, we need to switch to a 1:1 mapping for the
101 * cpu_reset functions. This will then ensure that we have predictable
102 * results when turning off the mmu.
103 */
104void setup_mm_for_reboot(void)
105{
106	/* Clean and invalidate L1. */
107	flush_cache_all();
108
109	/* Switch to the identity mapping. */
110	cpu_switch_mm(idmap_pgd, &init_mm);
111
112	/* Flush the TLB. */
113	local_flush_tlb_all();
114}