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git.proxmox.com Git - mirror_ubuntu-hirsute-kernel.git/blob - arch/arm/kernel/efi.c
1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
8 #include <asm/mach/map.h>
9 #include <asm/mmu_context.h>
11 static int __init
set_permissions(pte_t
*ptep
, pgtable_t token
,
12 unsigned long addr
, void *data
)
14 efi_memory_desc_t
*md
= data
;
17 if (md
->attribute
& EFI_MEMORY_RO
)
18 pte
= set_pte_bit(pte
, __pgprot(L_PTE_RDONLY
));
19 if (md
->attribute
& EFI_MEMORY_XP
)
20 pte
= set_pte_bit(pte
, __pgprot(L_PTE_XN
));
21 set_pte_ext(ptep
, pte
, PTE_EXT_NG
);
25 int __init
efi_set_mapping_permissions(struct mm_struct
*mm
,
26 efi_memory_desc_t
*md
)
28 unsigned long base
, size
;
31 size
= md
->num_pages
<< EFI_PAGE_SHIFT
;
34 * We can only use apply_to_page_range() if we can guarantee that the
35 * entire region was mapped using pages. This should be the case if the
36 * region does not cover any naturally aligned SECTION_SIZE sized
39 if (round_down(base
+ size
, SECTION_SIZE
) <
40 round_up(base
, SECTION_SIZE
) + SECTION_SIZE
)
41 return apply_to_page_range(mm
, base
, size
, set_permissions
, md
);
46 int __init
efi_create_mapping(struct mm_struct
*mm
, efi_memory_desc_t
*md
)
48 struct map_desc desc
= {
49 .virtual = md
->virt_addr
,
50 .pfn
= __phys_to_pfn(md
->phys_addr
),
51 .length
= md
->num_pages
* EFI_PAGE_SIZE
,
55 * Order is important here: memory regions may have all of the
56 * bits below set (and usually do), so we check them in order of
59 if (md
->attribute
& EFI_MEMORY_WB
)
60 desc
.type
= MT_MEMORY_RWX
;
61 else if (md
->attribute
& EFI_MEMORY_WT
)
62 desc
.type
= MT_MEMORY_RWX_NONCACHED
;
63 else if (md
->attribute
& EFI_MEMORY_WC
)
64 desc
.type
= MT_DEVICE_WC
;
66 desc
.type
= MT_DEVICE
;
68 create_mapping_late(mm
, &desc
, true);
71 * If stricter permissions were specified, apply them now.
73 if (md
->attribute
& (EFI_MEMORY_RO
| EFI_MEMORY_XP
))
74 return efi_set_mapping_permissions(mm
, md
);