1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Extensible Firmware Interface
4 *
5 * Based on Extensible Firmware Interface Specification version 2.4
6 *
7 * Copyright (C) 2013, 2014 Linaro Ltd.
8 */
9
10#include <linux/dmi.h>
11#include <linux/efi.h>
12#include <linux/io.h>
13#include <linux/memblock.h>
14#include <linux/mm_types.h>
15#include <linux/preempt.h>
16#include <linux/rbtree.h>
17#include <linux/rwsem.h>
18#include <linux/sched.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21#include <linux/pgtable.h>
22
23#include <asm/cacheflush.h>
24#include <asm/efi.h>
25#include <asm/mmu.h>
26#include <asm/pgalloc.h>
27
28#if defined(CONFIG_PTDUMP_DEBUGFS) && defined(CONFIG_ARM64)
29#include <asm/ptdump.h>
30
31static struct ptdump_info efi_ptdump_info = {
32	.mm		= &efi_mm,
33	.markers	= (struct addr_marker[]){
34		{ 0,				"UEFI runtime start" },
35		{ DEFAULT_MAP_WINDOW_64,	"UEFI runtime end" },
36		{ -1,				NULL }
37	},
38	.base_addr	= 0,
39};
40
41static int __init ptdump_init(void)
42{
43	if (efi_enabled(EFI_RUNTIME_SERVICES))
44		ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");
45
46	return 0;
47}
48device_initcall(ptdump_init);
49
50#endif
51
52static bool __init efi_virtmap_init(void)
53{
54	efi_memory_desc_t *md;
55
56	efi_mm.pgd = pgd_alloc(&efi_mm);
57	mm_init_cpumask(&efi_mm);
58	init_new_context(NULL, &efi_mm);
59
60	for_each_efi_memory_desc(md) {
61		phys_addr_t phys = md->phys_addr;
62		int ret;
63
64		if (!(md->attribute & EFI_MEMORY_RUNTIME))
65			continue;
66		if (md->virt_addr == 0)
67			return false;
68
69		ret = efi_create_mapping(&efi_mm, md);
70		if (ret) {
71			pr_warn("  EFI remap %pa: failed to create mapping (%d)\n",
72				&phys, ret);
73			return false;
74		}
75	}
76
77	if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
78		return false;
79
80	return true;
81}
82
83/*
84 * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
85 * non-early mapping of the UEFI system table and virtual mappings for all
86 * EFI_MEMORY_RUNTIME regions.
87 */
88static int __init arm_enable_runtime_services(void)
89{
90	u64 mapsize;
91
92	if (!efi_enabled(EFI_BOOT)) {
93		pr_info("EFI services will not be available.\n");
94		return 0;
95	}
96
97	efi_memmap_unmap();
98
99	mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
100
101	if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
102		pr_err("Failed to remap EFI memory map\n");
103		return 0;
104	}
105
106	if (efi_soft_reserve_enabled()) {
107		efi_memory_desc_t *md;
108
109		for_each_efi_memory_desc(md) {
110			int md_size = md->num_pages << EFI_PAGE_SHIFT;
111			struct resource *res;
112
113			if (!(md->attribute & EFI_MEMORY_SP))
114				continue;
115
116			res = kzalloc(sizeof(*res), GFP_KERNEL);
117			if (WARN_ON(!res))
118				break;
119
120			res->start	= md->phys_addr;
121			res->end	= md->phys_addr + md_size - 1;
122			res->name	= "Soft Reserved";
123			res->flags	= IORESOURCE_MEM;
124			res->desc	= IORES_DESC_SOFT_RESERVED;
125
126			insert_resource(&iomem_resource, res);
127		}
128	}
129
130	if (efi_runtime_disabled()) {
131		pr_info("EFI runtime services will be disabled.\n");
132		return 0;
133	}
134
135	if (efi_enabled(EFI_RUNTIME_SERVICES)) {
136		pr_info("EFI runtime services access via paravirt.\n");
137		return 0;
138	}
139
140	pr_info("Remapping and enabling EFI services.\n");
141
142	if (!efi_virtmap_init()) {
143		pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
144		return -ENOMEM;
145	}
146
147	/* Set up runtime services function pointers */
148	efi_native_runtime_setup();
149	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
150
151	return 0;
152}
153early_initcall(arm_enable_runtime_services);
154
155void efi_virtmap_load(void)
156{
157	preempt_disable();
158	efi_set_pgd(&efi_mm);
159}
160
161void efi_virtmap_unload(void)
162{
163	efi_set_pgd(current->active_mm);
164	preempt_enable();
165}
166
167
168static int __init arm_dmi_init(void)
169{
170	/*
171	 * On arm64/ARM, DMI depends on UEFI, and dmi_setup() needs to
172	 * be called early because dmi_id_init(), which is an arch_initcall
173	 * itself, depends on dmi_scan_machine() having been called already.
174	 */
175	dmi_setup();
176	return 0;
177}
178core_initcall(arm_dmi_init);
179