aboutsummaryrefslogtreecommitdiff
path: root/drivers/firmware/efi/arm-runtime.c
blob: 9dda2602c862ad08622439abae2935148f3de1b0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
// SPDX-License-Identifier: GPL-2.0
/*
 * Extensible Firmware Interface
 *
 * Based on Extensible Firmware Interface Specification version 2.4
 *
 * Copyright (C) 2013, 2014 Linaro Ltd.
 */

#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/io.h>
#include <linux/memblock.h>
#include <linux/mm_types.h>
#include <linux/preempt.h>
#include <linux/rbtree.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <asm/cacheflush.h>
#include <asm/efi.h>
#include <asm/mmu.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>

extern u64 efi_system_table;

#if defined(CONFIG_PTDUMP_DEBUGFS) && defined(CONFIG_ARM64)
#include <asm/ptdump.h>

static struct ptdump_info efi_ptdump_info = {
	.mm		= &efi_mm,
	.markers	= (struct addr_marker[]){
		{ 0,				"UEFI runtime start" },
		{ DEFAULT_MAP_WINDOW_64,	"UEFI runtime end" },
		{ -1,				NULL }
	},
	.base_addr	= 0,
};

static int __init ptdump_init(void)
{
	if (efi_enabled(EFI_RUNTIME_SERVICES))
		ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");

	return 0;
}
device_initcall(ptdump_init);

#endif

static bool __init efi_virtmap_init(void)
{
	efi_memory_desc_t *md;
	bool systab_found;

	efi_mm.pgd = pgd_alloc(&efi_mm);
	mm_init_cpumask(&efi_mm);
	init_new_context(NULL, &efi_mm);

	systab_found = false;
	for_each_efi_memory_desc(md) {
		phys_addr_t phys = md->phys_addr;
		int ret;

		if (!(md->attribute & EFI_MEMORY_RUNTIME))
			continue;
		if (md->virt_addr == 0)
			return false;

		ret = efi_create_mapping(&efi_mm, md);
		if (ret) {
			pr_warn("  EFI remap %pa: failed to create mapping (%d)\n",
				&phys, ret);
			return false;
		}
		/*
		 * If this entry covers the address of the UEFI system table,
		 * calculate and record its virtual address.
		 */
		if (efi_system_table >= phys &&
		    efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) {
			efi.systab = (void *)(unsigned long)(efi_system_table -
							     phys + md->virt_addr);
			systab_found = true;
		}
	}
	if (!systab_found) {
		pr_err("No virtual mapping found for the UEFI System Table\n");
		return false;
	}

	if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
		return false;

	return true;
}

/*
 * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
 * non-early mapping of the UEFI system table and virtual mappings for all
 * EFI_MEMORY_RUNTIME regions.
 */
static int __init arm_enable_runtime_services(void)
{
	u64 mapsize;

	if (!efi_enabled(EFI_BOOT)) {
		pr_info("EFI services will not be available.\n");
		return 0;
	}

	efi_memmap_unmap();

	mapsize = efi.memmap.desc_size * efi.memmap.nr_map;

	if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
		pr_err("Failed to remap EFI memory map\n");
		return 0;
	}

	if (efi_soft_reserve_enabled()) {
		efi_memory_desc_t *md;

		for_each_efi_memory_desc(md) {
			int md_size = md->num_pages << EFI_PAGE_SHIFT;
			struct resource *res;

			if (!(md->attribute & EFI_MEMORY_SP))
				continue;

			res = kzalloc(sizeof(*res), GFP_KERNEL);
			if (WARN_ON(!res))
				break;

			res->start	= md->phys_addr;
			res->end	= md->phys_addr + md_size - 1;
			res->name	= "Soft Reserved";
			res->flags	= IORESOURCE_MEM;
			res->desc	= IORES_DESC_SOFT_RESERVED;

			insert_resource(&iomem_resource, res);
		}
	}

	if (efi_runtime_disabled()) {
		pr_info("EFI runtime services will be disabled.\n");
		return 0;
	}

	if (efi_enabled(EFI_RUNTIME_SERVICES)) {
		pr_info("EFI runtime services access via paravirt.\n");
		return 0;
	}

	pr_info("Remapping and enabling EFI services.\n");

	if (!efi_virtmap_init()) {
		pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
		return -ENOMEM;
	}

	/* Set up runtime services function pointers */
	efi_native_runtime_setup();
	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);

	return 0;
}
early_initcall(arm_enable_runtime_services);

void efi_virtmap_load(void)
{
	preempt_disable();
	efi_set_pgd(&efi_mm);
}

void efi_virtmap_unload(void)
{
	efi_set_pgd(current->active_mm);
	preempt_enable();
}


static int __init arm_dmi_init(void)
{
	/*
	 * On arm64/ARM, DMI depends on UEFI, and dmi_setup() needs to
	 * be called early because dmi_id_init(), which is an arch_initcall
	 * itself, depends on dmi_scan_machine() having been called already.
	 */
	dmi_setup();
	return 0;
}
core_initcall(arm_dmi_init);