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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 <linux/memblock.h>
8#include <asm/efi.h>
9#include <asm/mach/map.h>
10#include <asm/mmu_context.h>
11
12static int __init set_permissions(pte_t *ptep, 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
25int __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
46int __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);
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);
75 return 0;
76}
77
78static unsigned long __initdata cpu_state_table = EFI_INVALID_TABLE_ADDR;
79
80const efi_config_table_type_t efi_arch_tables[] __initconst = {
81 {LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table},
82 {}
83};
84
85static void __init load_cpu_state_table(void)
86{
87 if (cpu_state_table != EFI_INVALID_TABLE_ADDR) {
88 struct efi_arm_entry_state *state;
89 bool dump_state = true;
90
91 state = early_memremap_ro(cpu_state_table,
92 sizeof(struct efi_arm_entry_state));
93 if (state == NULL) {
94 pr_warn("Unable to map CPU entry state table.\n");
95 return;
96 }
97
98 if ((state->sctlr_before_ebs & 1) == 0)
99 pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n");
100 else if ((state->sctlr_after_ebs & 1) == 0)
101 pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n");
102 else
103 dump_state = false;
104
105 if (dump_state || efi_enabled(EFI_DBG)) {
106 pr_info("CPSR at EFI stub entry : 0x%08x\n",
107 state->cpsr_before_ebs);
108 pr_info("SCTLR at EFI stub entry : 0x%08x\n",
109 state->sctlr_before_ebs);
110 pr_info("CPSR after ExitBootServices() : 0x%08x\n",
111 state->cpsr_after_ebs);
112 pr_info("SCTLR after ExitBootServices(): 0x%08x\n",
113 state->sctlr_after_ebs);
114 }
115 early_memunmap(state, sizeof(struct efi_arm_entry_state));
116 }
117}
118
119void __init arm_efi_init(void)
120{
121 efi_init();
122
123 if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI) {
124 /* dummycon on ARM needs non-zero values for columns/lines */
125 screen_info.orig_video_cols = 80;
126 screen_info.orig_video_lines = 25;
127 }
128
129 /* ARM does not permit early mappings to persist across paging_init() */
130 efi_memmap_unmap();
131
132 load_cpu_state_table();
133}