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75 lines
2.0 KiB
75 lines
2.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2015 Linaro Ltd <[email protected]> |
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*/ |
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#include <linux/efi.h> |
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#include <asm/efi.h> |
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#include <asm/mach/map.h> |
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#include <asm/mmu_context.h> |
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static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) |
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{ |
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efi_memory_desc_t *md = data; |
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pte_t pte = *ptep; |
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if (md->attribute & EFI_MEMORY_RO) |
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pte = set_pte_bit(pte, __pgprot(L_PTE_RDONLY)); |
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if (md->attribute & EFI_MEMORY_XP) |
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pte = set_pte_bit(pte, __pgprot(L_PTE_XN)); |
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set_pte_ext(ptep, pte, PTE_EXT_NG); |
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return 0; |
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} |
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int __init efi_set_mapping_permissions(struct mm_struct *mm, |
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efi_memory_desc_t *md) |
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{ |
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unsigned long base, size; |
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base = md->virt_addr; |
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size = md->num_pages << EFI_PAGE_SHIFT; |
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/* |
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* We can only use apply_to_page_range() if we can guarantee that the |
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* entire region was mapped using pages. This should be the case if the |
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* region does not cover any naturally aligned SECTION_SIZE sized |
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* blocks. |
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*/ |
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if (round_down(base + size, SECTION_SIZE) < |
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round_up(base, SECTION_SIZE) + SECTION_SIZE) |
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return apply_to_page_range(mm, base, size, set_permissions, md); |
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return 0; |
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} |
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int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) |
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{ |
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struct map_desc desc = { |
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.virtual = md->virt_addr, |
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.pfn = __phys_to_pfn(md->phys_addr), |
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.length = md->num_pages * EFI_PAGE_SIZE, |
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}; |
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/* |
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* Order is important here: memory regions may have all of the |
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* bits below set (and usually do), so we check them in order of |
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* preference. |
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*/ |
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if (md->attribute & EFI_MEMORY_WB) |
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desc.type = MT_MEMORY_RWX; |
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else if (md->attribute & EFI_MEMORY_WT) |
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desc.type = MT_MEMORY_RWX_NONCACHED; |
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else if (md->attribute & EFI_MEMORY_WC) |
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desc.type = MT_DEVICE_WC; |
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else |
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desc.type = MT_DEVICE; |
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create_mapping_late(mm, &desc, true); |
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/* |
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* If stricter permissions were specified, apply them now. |
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*/ |
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if (md->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP)) |
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return efi_set_mapping_permissions(mm, md); |
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return 0; |
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}
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