projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| da58fb65 AB |
2 | /* |
| 3 | * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org> | |
| da58fb65 AB |
4 | */ |
| 5 | ||
| 6 | #include <linux/efi.h> | |
| 7 | #include <asm/efi.h> | |
| 8 | #include <asm/mach/map.h> | |
| 9 | #include <asm/mmu_context.h> | |
| 10 | ||
| 9fc68b71 AB |
11 | static int __init set_permissions(pte_t *ptep, pgtable_t token, |
| 12 | unsigned long addr, void *data) | |
| 13 | { | |
| 14 | efi_memory_desc_t *md = data; | |
| 15 | pte_t pte = *ptep; | |
| 16 | ||
| 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); | |
| 22 | return 0; | |
| 23 | } | |
| 24 | ||
| 25 | int __init efi_set_mapping_permissions(struct mm_struct *mm, | |
| 26 | efi_memory_desc_t *md) | |
| 27 | { | |
| 28 | unsigned long base, size; | |
| 29 | ||
| 30 | base = md->virt_addr; | |
| 31 | size = md->num_pages << EFI_PAGE_SHIFT; | |
| 32 | ||
| 33 | /* | |
| 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 | |
| 37 | * blocks. | |
| 38 | */ | |
| 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); | |
| 42 | ||
| 43 | return 0; | |
| 44 | } | |
| 45 | ||
| da58fb65 AB |
46 | int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) |
| 47 | { | |
| 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, | |
| 52 | }; | |
| 53 | ||
| 54 | /* | |
| 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 | |
| 57 | * preference. | |
| 58 | */ | |
| 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; | |
| 65 | else | |
| 66 | desc.type = MT_DEVICE; | |
| 67 | ||
| 68 | create_mapping_late(mm, &desc, true); | |
| 9fc68b71 AB |
69 | |
| 70 | /* | |
| 71 | * If stricter permissions were specified, apply them now. | |
| 72 | */ | |
| 73 | if (md->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP)) | |
| 74 | return efi_set_mapping_permissions(mm, md); | |
| da58fb65 AB |
75 | return 0; |
| 76 | } |