[mirror_ubuntu-hirsute-kernel.git] / arch / arm64 / kernel / efi.c

/*
 * Extensible Firmware Interface
 *
 * Based on Extensible Firmware Interface Specification version 2.4
 *
 * Copyright (C) 2013, 2014 Linaro Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/atomic.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/export.h>
#include <linux/memblock.h>
#include <linux/mm_types.h>
#include <linux/bootmem.h>
#include <linux/of.h>
#include <linux/of_fdt.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/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>

struct efi_memory_map memmap;

static u64 efi_system_table;

static pgd_t efi_pgd[PTRS_PER_PGD] __page_aligned_bss;

static struct mm_struct efi_mm = {
	.mm_rb			= RB_ROOT,
	.pgd			= efi_pgd,
	.mm_users		= ATOMIC_INIT(2),
	.mm_count		= ATOMIC_INIT(1),
	.mmap_sem		= __RWSEM_INITIALIZER(efi_mm.mmap_sem),
	.page_table_lock	= __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),
};

static int __init is_normal_ram(efi_memory_desc_t *md)
{
	if (md->attribute & EFI_MEMORY_WB)
		return 1;
	return 0;
}

/*
 * Translate a EFI virtual address into a physical address: this is necessary,
 * as some data members of the EFI system table are virtually remapped after
 * SetVirtualAddressMap() has been called.
 */
static phys_addr_t efi_to_phys(unsigned long addr)
{
	efi_memory_desc_t *md;

	for_each_efi_memory_desc(&memmap, md) {
		if (!(md->attribute & EFI_MEMORY_RUNTIME))
			continue;
		if (md->virt_addr == 0)
			/* no virtual mapping has been installed by the stub */
			break;
		if (md->virt_addr <= addr &&
		    (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
			return md->phys_addr + addr - md->virt_addr;
	}
	return addr;
}

static int __init uefi_init(void)
{
	efi_char16_t *c16;
	void *config_tables;
	u64 table_size;
	char vendor[100] = "unknown";
	int i, retval;

	efi.systab = early_memremap(efi_system_table,
				    sizeof(efi_system_table_t));
	if (efi.systab == NULL) {
		pr_warn("Unable to map EFI system table.\n");
		return -ENOMEM;
	}

	set_bit(EFI_BOOT, &efi.flags);
	set_bit(EFI_64BIT, &efi.flags);

	/*
	 * Verify the EFI Table
	 */
	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
		pr_err("System table signature incorrect\n");
		retval = -EINVAL;
		goto out;
	}
	if ((efi.systab->hdr.revision >> 16) < 2)
		pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
			efi.systab->hdr.revision >> 16,
			efi.systab->hdr.revision & 0xffff);

	/* Show what we know for posterity */
	c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor),
			     sizeof(vendor) * sizeof(efi_char16_t));
	if (c16) {
		for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
			vendor[i] = c16[i];
		vendor[i] = '\0';
		early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
	}

	pr_info("EFI v%u.%.02u by %s\n",
		efi.systab->hdr.revision >> 16,
		efi.systab->hdr.revision & 0xffff, vendor);

	table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
	config_tables = early_memremap(efi_to_phys(efi.systab->tables),
				       table_size);

	retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
					 sizeof(efi_config_table_64_t), NULL);

	early_memunmap(config_tables, table_size);
out:
	early_memunmap(efi.systab,  sizeof(efi_system_table_t));
	return retval;
}

/*
 * Return true for RAM regions we want to permanently reserve.
 */
static __init int is_reserve_region(efi_memory_desc_t *md)
{
	switch (md->type) {
	case EFI_LOADER_CODE:
	case EFI_LOADER_DATA:
	case EFI_BOOT_SERVICES_CODE:
	case EFI_BOOT_SERVICES_DATA:
	case EFI_CONVENTIONAL_MEMORY:
	case EFI_PERSISTENT_MEMORY:
		return 0;
	default:
		break;
	}
	return is_normal_ram(md);
}

static __init void reserve_regions(void)
{
	efi_memory_desc_t *md;
	u64 paddr, npages, size;

	if (efi_enabled(EFI_DBG))
		pr_info("Processing EFI memory map:\n");

	for_each_efi_memory_desc(&memmap, md) {
		paddr = md->phys_addr;
		npages = md->num_pages;

		if (efi_enabled(EFI_DBG)) {
			char buf[64];

			pr_info("  0x%012llx-0x%012llx %s",
				paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
				efi_md_typeattr_format(buf, sizeof(buf), md));
		}

		memrange_efi_to_native(&paddr, &npages);
		size = npages << PAGE_SHIFT;

		if (is_normal_ram(md))
			early_init_dt_add_memory_arch(paddr, size);

		if (is_reserve_region(md)) {
			memblock_reserve(paddr, size);
			if (efi_enabled(EFI_DBG))
				pr_cont("*");
		}

		if (efi_enabled(EFI_DBG))
			pr_cont("\n");
	}

	set_bit(EFI_MEMMAP, &efi.flags);
}

void __init efi_init(void)
{
	struct efi_fdt_params params;

	/* Grab UEFI information placed in FDT by stub */
	if (!efi_get_fdt_params(&params))
		return;

	efi_system_table = params.system_table;

	memblock_reserve(params.mmap & PAGE_MASK,
			 PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
	memmap.phys_map = params.mmap;
	memmap.map = early_memremap(params.mmap, params.mmap_size);
	memmap.map_end = memmap.map + params.mmap_size;
	memmap.desc_size = params.desc_size;
	memmap.desc_version = params.desc_ver;

	if (uefi_init() < 0)
		return;

	reserve_regions();
	early_memunmap(memmap.map, params.mmap_size);
}

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

	init_new_context(NULL, &efi_mm);

	for_each_efi_memory_desc(&memmap, md) {
		u64 paddr, npages, size;
		pgprot_t prot;

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

		paddr = md->phys_addr;
		npages = md->num_pages;
		memrange_efi_to_native(&paddr, &npages);
		size = npages << PAGE_SHIFT;

		pr_info("  EFI remap 0x%016llx => %p\n",
			md->phys_addr, (void *)md->virt_addr);

		/*
		 * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
		 * executable, everything else can be mapped with the XN bits
		 * set.
		 */
		if (!is_normal_ram(md))
			prot = __pgprot(PROT_DEVICE_nGnRE);
		else if (md->type == EFI_RUNTIME_SERVICES_CODE ||
			 !PAGE_ALIGNED(md->phys_addr))
			prot = PAGE_KERNEL_EXEC;
		else
			prot = PAGE_KERNEL;

		create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size,
				   __pgprot(pgprot_val(prot) | PTE_NG));
	}
	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 arm64_enable_runtime_services(void)
{
	u64 mapsize;

	if (!efi_enabled(EFI_BOOT)) {
		pr_info("EFI services will not be available.\n");
		return -1;
	}

	if (efi_runtime_disabled()) {
		pr_info("EFI runtime services will be disabled.\n");
		return -1;
	}

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

	mapsize = memmap.map_end - memmap.map;
	memmap.map = (__force void *)ioremap_cache(memmap.phys_map,
						   mapsize);
	if (!memmap.map) {
		pr_err("Failed to remap EFI memory map\n");
		return -1;
	}
	memmap.map_end = memmap.map + mapsize;
	efi.memmap = &memmap;

	efi.systab = (__force void *)ioremap_cache(efi_system_table,
						   sizeof(efi_system_table_t));
	if (!efi.systab) {
		pr_err("Failed to remap EFI System Table\n");
		return -1;
	}
	set_bit(EFI_SYSTEM_TABLES, &efi.flags);

	if (!efi_virtmap_init()) {
		pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
		return -1;
	}

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

	efi.runtime_version = efi.systab->hdr.revision;

	return 0;
}
early_initcall(arm64_enable_runtime_services);

static int __init arm64_dmi_init(void)
{
	/*
	 * On arm64, DMI depends on UEFI, and dmi_scan_machine() 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_scan_machine();
	if (dmi_available)
		dmi_set_dump_stack_arch_desc();
	return 0;
}
core_initcall(arm64_dmi_init);

static void efi_set_pgd(struct mm_struct *mm)
{
	switch_mm(NULL, mm, NULL);
}

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();
}

/*
 * UpdateCapsule() depends on the system being shutdown via
 * ResetSystem().
 */
bool efi_poweroff_required(void)
{
	return efi_enabled(EFI_RUNTIME_SERVICES);
}
Commit	Line	Data
f84d0275 MS	1	/*
	2	* Extensible Firmware Interface
	3	*
	4	* Based on Extensible Firmware Interface Specification version 2.4
	5	*
	6	* Copyright (C) 2013, 2014 Linaro Ltd.
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	*/
	13
f3cdfd23	14	#include <linux/atomic.h>
d1ae8c00	15	#include <linux/dmi.h>
f84d0275 MS	16	#include <linux/efi.h>
	17	#include <linux/export.h>
	18	#include <linux/memblock.h>
f3cdfd23	19	#include <linux/mm_types.h>
f84d0275 MS	20	#include <linux/bootmem.h>
	21	#include <linux/of.h>
	22	#include <linux/of_fdt.h>
f3cdfd23 AB	23	#include <linux/preempt.h>
	24	#include <linux/rbtree.h>
	25	#include <linux/rwsem.h>
f84d0275 MS	26	#include <linux/sched.h>
f84d0275 MS	27	#include <linux/slab.h>
f3cdfd23	28	#include <linux/spinlock.h>
f84d0275 MS	29
	30	#include <asm/cacheflush.h>
	31	#include <asm/efi.h>
	32	#include <asm/tlbflush.h>
	33	#include <asm/mmu_context.h>
f3cdfd23 AB	34	#include <asm/mmu.h>
f3cdfd23 AB	35	#include <asm/pgtable.h>
f84d0275 MS	36
	37	struct efi_memory_map memmap;
	38
f84d0275 MS	39	static u64 efi_system_table;
f84d0275 MS	40
60305db9 AB	41	static pgd_t efi_pgd[PTRS_PER_PGD] __page_aligned_bss;
	42
	43	static struct mm_struct efi_mm = {
	44	.mm_rb = RB_ROOT,
	45	.pgd = efi_pgd,
	46	.mm_users = ATOMIC_INIT(2),
	47	.mm_count = ATOMIC_INIT(1),
	48	.mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
	49	.page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
	50	.mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
60305db9 AB	51	};
60305db9 AB	52
f84d0275 MS	53	static int __init is_normal_ram(efi_memory_desc_t *md)
	54	{
	55	if (md->attribute & EFI_MEMORY_WB)
	56	return 1;
	57	return 0;
	58	}
	59
f3cdfd23 AB	60	/*
	61	* Translate a EFI virtual address into a physical address: this is necessary,
	62	* as some data members of the EFI system table are virtually remapped after
	63	* SetVirtualAddressMap() has been called.
	64	*/
	65	static phys_addr_t efi_to_phys(unsigned long addr)
	66	{
	67	efi_memory_desc_t *md;
	68
	69	for_each_efi_memory_desc(&memmap, md) {
	70	if (!(md->attribute & EFI_MEMORY_RUNTIME))
	71	continue;
	72	if (md->virt_addr == 0)
	73	/* no virtual mapping has been installed by the stub */
	74	break;
	75	if (md->virt_addr <= addr &&
	76	(addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
	77	return md->phys_addr + addr - md->virt_addr;
	78	}
	79	return addr;
	80	}
	81
f84d0275 MS	82	static int __init uefi_init(void)
	83	{
	84	efi_char16_t *c16;
f3cdfd23 AB	85	void *config_tables;
f3cdfd23 AB	86	u64 table_size;
f84d0275 MS	87	char vendor[100] = "unknown";
	88	int i, retval;
	89
	90	efi.systab = early_memremap(efi_system_table,
	91	sizeof(efi_system_table_t));
	92	if (efi.systab == NULL) {
	93	pr_warn("Unable to map EFI system table.\n");
	94	return -ENOMEM;
	95	}
	96
	97	set_bit(EFI_BOOT, &efi.flags);
	98	set_bit(EFI_64BIT, &efi.flags);
	99
	100	/*
	101	* Verify the EFI Table
	102	*/
	103	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
	104	pr_err("System table signature incorrect\n");
88f8abd5 DY	105	retval = -EINVAL;
88f8abd5 DY	106	goto out;
f84d0275 MS	107	}
	108	if ((efi.systab->hdr.revision >> 16) < 2)
	109	pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
	110	efi.systab->hdr.revision >> 16,
	111	efi.systab->hdr.revision & 0xffff);
	112
	113	/* Show what we know for posterity */
f3cdfd23	114	c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor),
f91b1fea	115	sizeof(vendor) * sizeof(efi_char16_t));
f84d0275 MS	116	if (c16) {
	117	for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
	118	vendor[i] = c16[i];
	119	vendor[i] = '\0';
f91b1fea	120	early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
f84d0275 MS	121	}
	122
	123	pr_info("EFI v%u.%.02u by %s\n",
	124	efi.systab->hdr.revision >> 16,
	125	efi.systab->hdr.revision & 0xffff, vendor);
	126
f3cdfd23 AB	127	table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
	128	config_tables = early_memremap(efi_to_phys(efi.systab->tables),
	129	table_size);
	130
	131	retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
	132	sizeof(efi_config_table_64_t), NULL);
f84d0275	133
f3cdfd23	134	early_memunmap(config_tables, table_size);
88f8abd5	135	out:
f84d0275	136	early_memunmap(efi.systab, sizeof(efi_system_table_t));
f84d0275 MS	137	return retval;
	138	}
	139
f84d0275 MS	140	/*
	141	* Return true for RAM regions we want to permanently reserve.
	142	*/
	143	static __init int is_reserve_region(efi_memory_desc_t *md)
	144	{
61139eb0 AB	145	switch (md->type) {
	146	case EFI_LOADER_CODE:
	147	case EFI_LOADER_DATA:
	148	case EFI_BOOT_SERVICES_CODE:
	149	case EFI_BOOT_SERVICES_DATA:
	150	case EFI_CONVENTIONAL_MEMORY:
ad5fb870	151	case EFI_PERSISTENT_MEMORY:
f84d0275	152	return 0;
61139eb0 AB	153	default:
	154	break;
	155	}
	156	return is_normal_ram(md);
f84d0275 MS	157	}
	158
	159	static __init void reserve_regions(void)
	160	{
	161	efi_memory_desc_t *md;
	162	u64 paddr, npages, size;
	163
c9494dc8	164	if (efi_enabled(EFI_DBG))
f84d0275 MS	165	pr_info("Processing EFI memory map:\n");
	166
	167	for_each_efi_memory_desc(&memmap, md) {
	168	paddr = md->phys_addr;
	169	npages = md->num_pages;
	170
c9494dc8	171	if (efi_enabled(EFI_DBG)) {
65ba758f LE	172	char buf[64];
	173
	174	pr_info(" 0x%012llx-0x%012llx %s",
f84d0275	175	paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
65ba758f LE	176	efi_md_typeattr_format(buf, sizeof(buf), md));
65ba758f LE	177	}
f84d0275 MS	178
	179	memrange_efi_to_native(&paddr, &npages);
	180	size = npages << PAGE_SHIFT;
	181
	182	if (is_normal_ram(md))
	183	early_init_dt_add_memory_arch(paddr, size);
	184
3033b845	185	if (is_reserve_region(md)) {
f84d0275	186	memblock_reserve(paddr, size);
c9494dc8	187	if (efi_enabled(EFI_DBG))
f84d0275 MS	188	pr_cont("*");
	189	}
	190
c9494dc8	191	if (efi_enabled(EFI_DBG))
f84d0275 MS	192	pr_cont("\n");
f84d0275 MS	193	}
86c8b27a LL	194
86c8b27a LL	195	set_bit(EFI_MEMMAP, &efi.flags);
f84d0275 MS	196	}
f84d0275 MS	197
f84d0275 MS	198	void __init efi_init(void)
	199	{
	200	struct efi_fdt_params params;
	201
	202	/* Grab UEFI information placed in FDT by stub */
7968c0e3	203	if (!efi_get_fdt_params(&params))
f84d0275 MS	204	return;
	205
	206	efi_system_table = params.system_table;
	207
	208	memblock_reserve(params.mmap & PAGE_MASK,
	209	PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
44511fb9	210	memmap.phys_map = params.mmap;
f84d0275 MS	211	memmap.map = early_memremap(params.mmap, params.mmap_size);
	212	memmap.map_end = memmap.map + params.mmap_size;
	213	memmap.desc_size = params.desc_size;
	214	memmap.desc_version = params.desc_ver;
	215
	216	if (uefi_init() < 0)
	217	return;
	218
	219	reserve_regions();
60305db9 AB	220	early_memunmap(memmap.map, params.mmap_size);
	221	}
	222
	223	static bool __init efi_virtmap_init(void)
	224	{
	225	efi_memory_desc_t *md;
	226
65da0a8e AB	227	init_new_context(NULL, &efi_mm);
65da0a8e AB	228
60305db9 AB	229	for_each_efi_memory_desc(&memmap, md) {
	230	u64 paddr, npages, size;
	231	pgprot_t prot;
	232
	233	if (!(md->attribute & EFI_MEMORY_RUNTIME))
	234	continue;
	235	if (md->virt_addr == 0)
	236	return false;
	237
	238	paddr = md->phys_addr;
	239	npages = md->num_pages;
	240	memrange_efi_to_native(&paddr, &npages);
	241	size = npages << PAGE_SHIFT;
	242
	243	pr_info(" EFI remap 0x%016llx => %p\n",
	244	md->phys_addr, (void *)md->virt_addr);
	245
	246	/*
	247	* Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
	248	* executable, everything else can be mapped with the XN bits
	249	* set.
	250	*/
	251	if (!is_normal_ram(md))
	252	prot = __pgprot(PROT_DEVICE_nGnRE);
0ce3cc00 AB	253	else if (md->type == EFI_RUNTIME_SERVICES_CODE \|\|
0ce3cc00 AB	254	!PAGE_ALIGNED(md->phys_addr))
60305db9 AB	255	prot = PAGE_KERNEL_EXEC;
	256	else
	257	prot = PAGE_KERNEL;
	258
65da0a8e AB	259	create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size,
65da0a8e AB	260	__pgprot(pgprot_val(prot) \| PTE_NG));
60305db9 AB	261	}
60305db9 AB	262	return true;
f84d0275 MS	263	}
f84d0275 MS	264
f84d0275	265	/*
f3cdfd23 AB	266	* Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
	267	* non-early mapping of the UEFI system table and virtual mappings for all
	268	* EFI_MEMORY_RUNTIME regions.
f84d0275	269	*/
f3cdfd23	270	static int __init arm64_enable_runtime_services(void)
f84d0275	271	{
f84d0275	272	u64 mapsize;
f84d0275 MS	273
	274	if (!efi_enabled(EFI_BOOT)) {
	275	pr_info("EFI services will not be available.\n");
	276	return -1;
	277	}
	278
6632210f DY	279	if (efi_runtime_disabled()) {
	280	pr_info("EFI runtime services will be disabled.\n");
	281	return -1;
	282	}
	283
	284	pr_info("Remapping and enabling EFI services.\n");
7fe5d2b1 AB	285
7fe5d2b1 AB	286	mapsize = memmap.map_end - memmap.map;
44511fb9	287	memmap.map = (__force void *)ioremap_cache(memmap.phys_map,
f84d0275	288	mapsize);
7fe5d2b1 AB	289	if (!memmap.map) {
	290	pr_err("Failed to remap EFI memory map\n");
	291	return -1;
	292	}
f84d0275	293	memmap.map_end = memmap.map + mapsize;
f84d0275 MS	294	efi.memmap = &memmap;
f84d0275 MS	295
f3cdfd23 AB	296	efi.systab = (__force void *)ioremap_cache(efi_system_table,
f3cdfd23 AB	297	sizeof(efi_system_table_t));
99a5603e	298	if (!efi.systab) {
f3cdfd23 AB	299	pr_err("Failed to remap EFI System Table\n");
f3cdfd23 AB	300	return -1;
99a5603e AB	301	}
99a5603e AB	302	set_bit(EFI_SYSTEM_TABLES, &efi.flags);
f84d0275	303
60305db9	304	if (!efi_virtmap_init()) {
f3cdfd23	305	pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
f84d0275 MS	306	return -1;
	307	}
	308
	309	/* Set up runtime services function pointers */
e15dd494	310	efi_native_runtime_setup();
f84d0275 MS	311	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
f84d0275 MS	312
6a7519e8 SP	313	efi.runtime_version = efi.systab->hdr.revision;
6a7519e8 SP	314
f84d0275 MS	315	return 0;
f84d0275 MS	316	}
f3cdfd23	317	early_initcall(arm64_enable_runtime_services);
d1ae8c00 YL	318
	319	static int __init arm64_dmi_init(void)
	320	{
	321	/*
	322	* On arm64, DMI depends on UEFI, and dmi_scan_machine() needs to
	323	* be called early because dmi_id_init(), which is an arch_initcall
	324	* itself, depends on dmi_scan_machine() having been called already.
	325	*/
	326	dmi_scan_machine();
b07bfaa3 AB	327	if (dmi_available)
b07bfaa3 AB	328	dmi_set_dump_stack_arch_desc();
d1ae8c00 YL	329	return 0;
	330	}
	331	core_initcall(arm64_dmi_init);
f3cdfd23	332
f3cdfd23 AB	333	static void efi_set_pgd(struct mm_struct *mm)
f3cdfd23 AB	334	{
65da0a8e	335	switch_mm(NULL, mm, NULL);
f3cdfd23 AB	336	}
	337
	338	void efi_virtmap_load(void)
	339	{
	340	preempt_disable();
	341	efi_set_pgd(&efi_mm);
	342	}
	343
	344	void efi_virtmap_unload(void)
	345	{
	346	efi_set_pgd(current->active_mm);
	347	preempt_enable();
	348	}
60c0d45a AB	349
	350	/*
	351	* UpdateCapsule() depends on the system being shutdown via
	352	* ResetSystem().
	353	*/
	354	bool efi_poweroff_required(void)
	355	{
	356	return efi_enabled(EFI_RUNTIME_SERVICES);
	357	}