Commit | Line | Data |
---|---|---|
f84d0275 MS |
1 | /* |
2 | * Extensible Firmware Interface | |
3 | * | |
4 | * Based on Extensible Firmware Interface Specification version 2.4 | |
5 | * | |
6 | * Copyright (C) 2013, 2014 Linaro Ltd. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | * | |
12 | */ | |
13 | ||
d1ae8c00 | 14 | #include <linux/dmi.h> |
f84d0275 | 15 | #include <linux/efi.h> |
e5bc22a4 | 16 | #include <linux/init.h> |
f84d0275 | 17 | |
f84d0275 | 18 | #include <asm/efi.h> |
d1ae8c00 | 19 | |
1fd55a9a AB |
20 | /* |
21 | * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be | |
22 | * executable, everything else can be mapped with the XN bits | |
23 | * set. Also take the new (optional) RO/XP bits into account. | |
24 | */ | |
25 | static __init pteval_t create_mapping_protection(efi_memory_desc_t *md) | |
f7d92489 | 26 | { |
1fd55a9a AB |
27 | u64 attr = md->attribute; |
28 | u32 type = md->type; | |
f7d92489 | 29 | |
1fd55a9a AB |
30 | if (type == EFI_MEMORY_MAPPED_IO) |
31 | return PROT_DEVICE_nGnRE; | |
32 | ||
33 | if (WARN_ONCE(!PAGE_ALIGNED(md->phys_addr), | |
34 | "UEFI Runtime regions are not aligned to 64 KB -- buggy firmware?")) | |
35 | /* | |
36 | * If the region is not aligned to the page size of the OS, we | |
37 | * can not use strict permissions, since that would also affect | |
38 | * the mapping attributes of the adjacent regions. | |
39 | */ | |
40 | return pgprot_val(PAGE_KERNEL_EXEC); | |
41 | ||
42 | /* R-- */ | |
43 | if ((attr & (EFI_MEMORY_XP | EFI_MEMORY_RO)) == | |
44 | (EFI_MEMORY_XP | EFI_MEMORY_RO)) | |
45 | return pgprot_val(PAGE_KERNEL_RO); | |
46 | ||
47 | /* R-X */ | |
48 | if (attr & EFI_MEMORY_RO) | |
49 | return pgprot_val(PAGE_KERNEL_ROX); | |
50 | ||
51 | /* RW- */ | |
52 | if (attr & EFI_MEMORY_XP || type != EFI_RUNTIME_SERVICES_CODE) | |
53 | return pgprot_val(PAGE_KERNEL); | |
54 | ||
55 | /* RWX */ | |
56 | return pgprot_val(PAGE_KERNEL_EXEC); | |
57 | } | |
58 | ||
57fdb89a AB |
59 | /* we will fill this structure from the stub, so don't put it in .bss */ |
60 | struct screen_info screen_info __section(.data); | |
61 | ||
1fd55a9a AB |
62 | int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) |
63 | { | |
64 | pteval_t prot_val = create_mapping_protection(md); | |
f7d92489 AB |
65 | |
66 | create_pgd_mapping(mm, md->phys_addr, md->virt_addr, | |
67 | md->num_pages << EFI_PAGE_SHIFT, | |
68 | __pgprot(prot_val | PTE_NG)); | |
69 | return 0; | |
70 | } | |
71 | ||
d1ae8c00 YL |
72 | static int __init arm64_dmi_init(void) |
73 | { | |
74 | /* | |
75 | * On arm64, DMI depends on UEFI, and dmi_scan_machine() needs to | |
76 | * be called early because dmi_id_init(), which is an arch_initcall | |
77 | * itself, depends on dmi_scan_machine() having been called already. | |
78 | */ | |
79 | dmi_scan_machine(); | |
b07bfaa3 AB |
80 | if (dmi_available) |
81 | dmi_set_dump_stack_arch_desc(); | |
d1ae8c00 YL |
82 | return 0; |
83 | } | |
84 | core_initcall(arm64_dmi_init); | |
f3cdfd23 | 85 | |
60c0d45a AB |
86 | /* |
87 | * UpdateCapsule() depends on the system being shutdown via | |
88 | * ResetSystem(). | |
89 | */ | |
90 | bool efi_poweroff_required(void) | |
91 | { | |
92 | return efi_enabled(EFI_RUNTIME_SERVICES); | |
93 | } |