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614dd058 RK |
1 | #include <linux/kernel.h> |
2 | ||
3 | #include <asm/cputype.h> | |
8903826d | 4 | #include <asm/idmap.h> |
614dd058 RK |
5 | #include <asm/pgalloc.h> |
6 | #include <asm/pgtable.h> | |
8903826d | 7 | #include <asm/sections.h> |
9f97da78 | 8 | #include <asm/system_info.h> |
8903826d WD |
9 | |
10 | pgd_t *idmap_pgd; | |
614dd058 | 11 | |
ae2de101 CM |
12 | #ifdef CONFIG_ARM_LPAE |
13 | static 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 */ | |
516295e5 | 37 | static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end, |
af3813d6 RK |
38 | unsigned long prot) |
39 | { | |
516295e5 | 40 | pmd_t *pmd = pmd_offset(pud, addr); |
af3813d6 RK |
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 | } | |
ae2de101 | 48 | #endif /* CONFIG_ARM_LPAE */ |
af3813d6 | 49 | |
516295e5 RK |
50 | static 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 | ||
4e8ee7de | 62 | static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) |
614dd058 | 63 | { |
af3813d6 | 64 | unsigned long prot, next; |
614dd058 | 65 | |
ae2de101 | 66 | prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF; |
614dd058 RK |
67 | if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) |
68 | prot |= PMD_BIT4; | |
69 | ||
af3813d6 RK |
70 | pgd += pgd_index(addr); |
71 | do { | |
72 | next = pgd_addr_end(addr, end); | |
516295e5 | 73 | idmap_add_pud(pgd, addr, next, prot); |
af3813d6 | 74 | } while (pgd++, addr = next, addr != end); |
614dd058 RK |
75 | } |
76 | ||
8903826d WD |
77 | extern char __idmap_text_start[], __idmap_text_end[]; |
78 | ||
79 | static 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 | } | |
4e8ee7de | 97 | early_initcall(init_static_idmap); |
8903826d | 98 | |
614dd058 | 99 | /* |
2c8951ab WD |
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. | |
614dd058 | 103 | */ |
5aafec15 | 104 | void setup_mm_for_reboot(void) |
614dd058 | 105 | { |
2c8951ab WD |
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. */ | |
614dd058 RK |
113 | local_flush_tlb_all(); |
114 | } |