1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
 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
11static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
12{
13	efi_memory_desc_t *md = data;
14	pte_t pte = *ptep;
15
16	if (md->attribute & EFI_MEMORY_RO)
17		pte = set_pte_bit(pte, __pgprot(L_PTE_RDONLY));
18	if (md->attribute & EFI_MEMORY_XP)
19		pte = set_pte_bit(pte, __pgprot(L_PTE_XN));
20	set_pte_ext(ptep, pte, PTE_EXT_NG);
21	return 0;
22}
23
24int __init efi_set_mapping_permissions(struct mm_struct *mm,
25				       efi_memory_desc_t *md)
26{
27	unsigned long base, size;
28
29	base = md->virt_addr;
30	size = md->num_pages << EFI_PAGE_SHIFT;
31
32	/*
33	 * We can only use apply_to_page_range() if we can guarantee that the
34	 * entire region was mapped using pages. This should be the case if the
35	 * region does not cover any naturally aligned SECTION_SIZE sized
36	 * blocks.
37	 */
38	if (round_down(base + size, SECTION_SIZE) <
39	    round_up(base, SECTION_SIZE) + SECTION_SIZE)
40		return apply_to_page_range(mm, base, size, set_permissions, md);
41
42	return 0;
43}
44
45int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
46{
47	struct map_desc desc = {
48		.virtual	= md->virt_addr,
49		.pfn		= __phys_to_pfn(md->phys_addr),
50		.length		= md->num_pages * EFI_PAGE_SIZE,
51	};
52
53	/*
54	 * Order is important here: memory regions may have all of the
55	 * bits below set (and usually do), so we check them in order of
56	 * preference.
57	 */
58	if (md->attribute & EFI_MEMORY_WB)
59		desc.type = MT_MEMORY_RWX;
60	else if (md->attribute & EFI_MEMORY_WT)
61		desc.type = MT_MEMORY_RWX_NONCACHED;
62	else if (md->attribute & EFI_MEMORY_WC)
63		desc.type = MT_DEVICE_WC;
64	else
65		desc.type = MT_DEVICE;
66
67	create_mapping_late(mm, &desc, true);
68
69	/*
70	 * If stricter permissions were specified, apply them now.
71	 */
72	if (md->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP))
73		return efi_set_mapping_permissions(mm, md);
74	return 0;
75}

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
 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
11static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
12{
13	efi_memory_desc_t *md = data;
14	pte_t pte = *ptep;
15
16	if (md->attribute & EFI_MEMORY_RO)
17		pte = set_pte_bit(pte, __pgprot(L_PTE_RDONLY));
18	if (md->attribute & EFI_MEMORY_XP)
19		pte = set_pte_bit(pte, __pgprot(L_PTE_XN));
20	set_pte_ext(ptep, pte, PTE_EXT_NG);
21	return 0;
22}
23
24int __init efi_set_mapping_permissions(struct mm_struct *mm,
25				       efi_memory_desc_t *md)
26{
27	unsigned long base, size;
28
29	base = md->virt_addr;
30	size = md->num_pages << EFI_PAGE_SHIFT;
31
32	/*
33	 * We can only use apply_to_page_range() if we can guarantee that the
34	 * entire region was mapped using pages. This should be the case if the
35	 * region does not cover any naturally aligned SECTION_SIZE sized
36	 * blocks.
37	 */
38	if (round_down(base + size, SECTION_SIZE) <
39	    round_up(base, SECTION_SIZE) + SECTION_SIZE)
40		return apply_to_page_range(mm, base, size, set_permissions, md);
41
42	return 0;
43}
44
45int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
46{
47	struct map_desc desc = {
48		.virtual	= md->virt_addr,
49		.pfn		= __phys_to_pfn(md->phys_addr),
50		.length		= md->num_pages * EFI_PAGE_SIZE,
51	};
52
53	/*
54	 * Order is important here: memory regions may have all of the
55	 * bits below set (and usually do), so we check them in order of
56	 * preference.
57	 */
58	if (md->attribute & EFI_MEMORY_WB)
59		desc.type = MT_MEMORY_RWX;
60	else if (md->attribute & EFI_MEMORY_WT)
61		desc.type = MT_MEMORY_RWX_NONCACHED;
62	else if (md->attribute & EFI_MEMORY_WC)
63		desc.type = MT_DEVICE_WC;
64	else
65		desc.type = MT_DEVICE;
66
67	create_mapping_late(mm, &desc, true);
68
69	/*
70	 * If stricter permissions were specified, apply them now.
71	 */
72	if (md->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP))
73		return efi_set_mapping_permissions(mm, md);
74	return 0;
75}