Commit | Line | Data |
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9e9a367c | 1 | #include <linux/module.h> |
614dd058 | 2 | #include <linux/kernel.h> |
9e9a367c | 3 | #include <linux/slab.h> |
614dd058 RK |
4 | |
5 | #include <asm/cputype.h> | |
8903826d | 6 | #include <asm/idmap.h> |
614dd058 RK |
7 | #include <asm/pgalloc.h> |
8 | #include <asm/pgtable.h> | |
8903826d | 9 | #include <asm/sections.h> |
9f97da78 | 10 | #include <asm/system_info.h> |
8903826d WD |
11 | |
12 | pgd_t *idmap_pgd; | |
614dd058 | 13 | |
ae2de101 CM |
14 | #ifdef CONFIG_ARM_LPAE |
15 | static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end, | |
16 | unsigned long prot) | |
17 | { | |
18 | pmd_t *pmd; | |
19 | unsigned long next; | |
20 | ||
21 | if (pud_none_or_clear_bad(pud) || (pud_val(*pud) & L_PGD_SWAPPER)) { | |
22 | pmd = pmd_alloc_one(&init_mm, addr); | |
23 | if (!pmd) { | |
24 | pr_warning("Failed to allocate identity pmd.\n"); | |
25 | return; | |
26 | } | |
27 | pud_populate(&init_mm, pud, pmd); | |
28 | pmd += pmd_index(addr); | |
29 | } else | |
30 | pmd = pmd_offset(pud, addr); | |
31 | ||
32 | do { | |
33 | next = pmd_addr_end(addr, end); | |
34 | *pmd = __pmd((addr & PMD_MASK) | prot); | |
35 | flush_pmd_entry(pmd); | |
36 | } while (pmd++, addr = next, addr != end); | |
37 | } | |
38 | #else /* !CONFIG_ARM_LPAE */ | |
516295e5 | 39 | static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end, |
af3813d6 RK |
40 | unsigned long prot) |
41 | { | |
516295e5 | 42 | pmd_t *pmd = pmd_offset(pud, addr); |
af3813d6 RK |
43 | |
44 | addr = (addr & PMD_MASK) | prot; | |
45 | pmd[0] = __pmd(addr); | |
46 | addr += SECTION_SIZE; | |
47 | pmd[1] = __pmd(addr); | |
48 | flush_pmd_entry(pmd); | |
49 | } | |
ae2de101 | 50 | #endif /* CONFIG_ARM_LPAE */ |
af3813d6 | 51 | |
516295e5 RK |
52 | static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end, |
53 | unsigned long prot) | |
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_add_pmd(pud, addr, next, prot); | |
61 | } while (pud++, addr = next, addr != end); | |
62 | } | |
63 | ||
9e9a367c CD |
64 | static void identity_mapping_add(pgd_t *pgd, const char *text_start, |
65 | const char *text_end, unsigned long prot) | |
614dd058 | 66 | { |
9e9a367c CD |
67 | unsigned long addr, end; |
68 | unsigned long next; | |
69 | ||
70 | addr = virt_to_phys(text_start); | |
71 | end = virt_to_phys(text_end); | |
72 | ||
73 | prot |= PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF; | |
614dd058 | 74 | |
614dd058 RK |
75 | if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) |
76 | prot |= PMD_BIT4; | |
77 | ||
af3813d6 RK |
78 | pgd += pgd_index(addr); |
79 | do { | |
80 | next = pgd_addr_end(addr, end); | |
516295e5 | 81 | idmap_add_pud(pgd, addr, next, prot); |
af3813d6 | 82 | } while (pgd++, addr = next, addr != end); |
614dd058 RK |
83 | } |
84 | ||
8903826d WD |
85 | extern char __idmap_text_start[], __idmap_text_end[]; |
86 | ||
87 | static int __init init_static_idmap(void) | |
88 | { | |
8903826d WD |
89 | idmap_pgd = pgd_alloc(&init_mm); |
90 | if (!idmap_pgd) | |
91 | return -ENOMEM; | |
92 | ||
9e9a367c CD |
93 | pr_info("Setting up static identity map for 0x%p - 0x%p\n", |
94 | __idmap_text_start, __idmap_text_end); | |
95 | identity_mapping_add(idmap_pgd, __idmap_text_start, | |
96 | __idmap_text_end, 0); | |
8903826d | 97 | |
e4067855 NP |
98 | /* Flush L1 for the hardware to see this page table content */ |
99 | flush_cache_louis(); | |
100 | ||
2fb41059 | 101 | return 0; |
8903826d | 102 | } |
4e8ee7de | 103 | early_initcall(init_static_idmap); |
8903826d | 104 | |
614dd058 | 105 | /* |
2c8951ab WD |
106 | * In order to soft-boot, we need to switch to a 1:1 mapping for the |
107 | * cpu_reset functions. This will then ensure that we have predictable | |
108 | * results when turning off the mmu. | |
614dd058 | 109 | */ |
5aafec15 | 110 | void setup_mm_for_reboot(void) |
614dd058 | 111 | { |
2c8951ab WD |
112 | /* Switch to the identity mapping. */ |
113 | cpu_switch_mm(idmap_pgd, &init_mm); | |
89c7e4b8 | 114 | local_flush_bp_all(); |
2c8951ab | 115 | |
e4067855 NP |
116 | #ifdef CONFIG_CPU_HAS_ASID |
117 | /* | |
118 | * We don't have a clean ASID for the identity mapping, which | |
119 | * may clash with virtual addresses of the previous page tables | |
120 | * and therefore potentially in the TLB. | |
121 | */ | |
614dd058 | 122 | local_flush_tlb_all(); |
e4067855 | 123 | #endif |
614dd058 | 124 | } |