[mirror_ubuntu-artful-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),
	INIT_MM_CONTEXT(efi_mm)
};

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 = (void *)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;

	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)
			prot = PAGE_KERNEL_EXEC;
		else
			prot = PAGE_KERNEL;

		create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size, prot);
	}
	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((phys_addr_t)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)
{
	if (mm == &init_mm)
		cpu_set_reserved_ttbr0();
	else
		cpu_switch_mm(mm->pgd, mm);

	flush_tlb_all();
	if (icache_is_aivivt())
		__flush_icache_all();
}

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),
	51	INIT_MM_CONTEXT(efi_mm)
	52	};
	53
f84d0275 MS	54	static int __init is_normal_ram(efi_memory_desc_t *md)
	55	{
	56	if (md->attribute & EFI_MEMORY_WB)
	57	return 1;
	58	return 0;
	59	}
	60
f3cdfd23 AB	61	/*
	62	* Translate a EFI virtual address into a physical address: this is necessary,
	63	* as some data members of the EFI system table are virtually remapped after
	64	* SetVirtualAddressMap() has been called.
	65	*/
	66	static phys_addr_t efi_to_phys(unsigned long addr)
	67	{
	68	efi_memory_desc_t *md;
	69
	70	for_each_efi_memory_desc(&memmap, md) {
	71	if (!(md->attribute & EFI_MEMORY_RUNTIME))
	72	continue;
	73	if (md->virt_addr == 0)
	74	/* no virtual mapping has been installed by the stub */
	75	break;
	76	if (md->virt_addr <= addr &&
	77	(addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
	78	return md->phys_addr + addr - md->virt_addr;
	79	}
	80	return addr;
	81	}
	82
f84d0275 MS	83	static int __init uefi_init(void)
	84	{
	85	efi_char16_t *c16;
f3cdfd23 AB	86	void *config_tables;
f3cdfd23 AB	87	u64 table_size;
f84d0275 MS	88	char vendor[100] = "unknown";
	89	int i, retval;
	90
	91	efi.systab = early_memremap(efi_system_table,
	92	sizeof(efi_system_table_t));
	93	if (efi.systab == NULL) {
	94	pr_warn("Unable to map EFI system table.\n");
	95	return -ENOMEM;
	96	}
	97
	98	set_bit(EFI_BOOT, &efi.flags);
	99	set_bit(EFI_64BIT, &efi.flags);
	100
	101	/*
	102	* Verify the EFI Table
	103	*/
	104	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
	105	pr_err("System table signature incorrect\n");
88f8abd5 DY	106	retval = -EINVAL;
88f8abd5 DY	107	goto out;
f84d0275 MS	108	}
	109	if ((efi.systab->hdr.revision >> 16) < 2)
	110	pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
	111	efi.systab->hdr.revision >> 16,
	112	efi.systab->hdr.revision & 0xffff);
	113
	114	/* Show what we know for posterity */
f3cdfd23	115	c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor),
f91b1fea	116	sizeof(vendor) * sizeof(efi_char16_t));
f84d0275 MS	117	if (c16) {
	118	for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
	119	vendor[i] = c16[i];
	120	vendor[i] = '\0';
f91b1fea	121	early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
f84d0275 MS	122	}
	123
	124	pr_info("EFI v%u.%.02u by %s\n",
	125	efi.systab->hdr.revision >> 16,
	126	efi.systab->hdr.revision & 0xffff, vendor);
	127
f3cdfd23 AB	128	table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
	129	config_tables = early_memremap(efi_to_phys(efi.systab->tables),
	130	table_size);
	131
	132	retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
	133	sizeof(efi_config_table_64_t), NULL);
f84d0275	134
f3cdfd23	135	early_memunmap(config_tables, table_size);
88f8abd5	136	out:
f84d0275	137	early_memunmap(efi.systab, sizeof(efi_system_table_t));
f84d0275 MS	138	return retval;
	139	}
	140
f84d0275 MS	141	/*
	142	* Return true for RAM regions we want to permanently reserve.
	143	*/
	144	static __init int is_reserve_region(efi_memory_desc_t *md)
	145	{
61139eb0 AB	146	switch (md->type) {
	147	case EFI_LOADER_CODE:
	148	case EFI_LOADER_DATA:
	149	case EFI_BOOT_SERVICES_CODE:
	150	case EFI_BOOT_SERVICES_DATA:
	151	case EFI_CONVENTIONAL_MEMORY:
ad5fb870	152	case EFI_PERSISTENT_MEMORY:
f84d0275	153	return 0;
61139eb0 AB	154	default:
	155	break;
	156	}
	157	return is_normal_ram(md);
f84d0275 MS	158	}
	159
	160	static __init void reserve_regions(void)
	161	{
	162	efi_memory_desc_t *md;
	163	u64 paddr, npages, size;
	164
c9494dc8	165	if (efi_enabled(EFI_DBG))
f84d0275 MS	166	pr_info("Processing EFI memory map:\n");
	167
	168	for_each_efi_memory_desc(&memmap, md) {
	169	paddr = md->phys_addr;
	170	npages = md->num_pages;
	171
c9494dc8	172	if (efi_enabled(EFI_DBG)) {
65ba758f LE	173	char buf[64];
	174
	175	pr_info(" 0x%012llx-0x%012llx %s",
f84d0275	176	paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
65ba758f LE	177	efi_md_typeattr_format(buf, sizeof(buf), md));
65ba758f LE	178	}
f84d0275 MS	179
	180	memrange_efi_to_native(&paddr, &npages);
	181	size = npages << PAGE_SHIFT;
	182
	183	if (is_normal_ram(md))
	184	early_init_dt_add_memory_arch(paddr, size);
	185
3033b845	186	if (is_reserve_region(md)) {
f84d0275	187	memblock_reserve(paddr, size);
c9494dc8	188	if (efi_enabled(EFI_DBG))
f84d0275 MS	189	pr_cont("*");
	190	}
	191
c9494dc8	192	if (efi_enabled(EFI_DBG))
f84d0275 MS	193	pr_cont("\n");
f84d0275 MS	194	}
86c8b27a LL	195
86c8b27a LL	196	set_bit(EFI_MEMMAP, &efi.flags);
f84d0275 MS	197	}
f84d0275 MS	198
f84d0275 MS	199	void __init efi_init(void)
	200	{
	201	struct efi_fdt_params params;
	202
	203	/* Grab UEFI information placed in FDT by stub */
7968c0e3	204	if (!efi_get_fdt_params(&params))
f84d0275 MS	205	return;
	206
	207	efi_system_table = params.system_table;
	208
	209	memblock_reserve(params.mmap & PAGE_MASK,
	210	PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
	211	memmap.phys_map = (void *)params.mmap;
	212	memmap.map = early_memremap(params.mmap, params.mmap_size);
	213	memmap.map_end = memmap.map + params.mmap_size;
	214	memmap.desc_size = params.desc_size;
	215	memmap.desc_version = params.desc_ver;
	216
	217	if (uefi_init() < 0)
	218	return;
	219
	220	reserve_regions();
60305db9 AB	221	early_memunmap(memmap.map, params.mmap_size);
	222	}
	223
	224	static bool __init efi_virtmap_init(void)
	225	{
	226	efi_memory_desc_t *md;
	227
	228	for_each_efi_memory_desc(&memmap, md) {
	229	u64 paddr, npages, size;
	230	pgprot_t prot;
	231
	232	if (!(md->attribute & EFI_MEMORY_RUNTIME))
	233	continue;
	234	if (md->virt_addr == 0)
	235	return false;
	236
	237	paddr = md->phys_addr;
	238	npages = md->num_pages;
	239	memrange_efi_to_native(&paddr, &npages);
	240	size = npages << PAGE_SHIFT;
	241
	242	pr_info(" EFI remap 0x%016llx => %p\n",
	243	md->phys_addr, (void *)md->virt_addr);
	244
	245	/*
	246	* Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
	247	* executable, everything else can be mapped with the XN bits
	248	* set.
	249	*/
	250	if (!is_normal_ram(md))
	251	prot = __pgprot(PROT_DEVICE_nGnRE);
	252	else if (md->type == EFI_RUNTIME_SERVICES_CODE)
	253	prot = PAGE_KERNEL_EXEC;
	254	else
	255	prot = PAGE_KERNEL;
	256
	257	create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size, prot);
	258	}
	259	return true;
f84d0275 MS	260	}
f84d0275 MS	261
f84d0275	262	/*
f3cdfd23 AB	263	* Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
	264	* non-early mapping of the UEFI system table and virtual mappings for all
	265	* EFI_MEMORY_RUNTIME regions.
f84d0275	266	*/
f3cdfd23	267	static int __init arm64_enable_runtime_services(void)
f84d0275	268	{
f84d0275	269	u64 mapsize;
f84d0275 MS	270
	271	if (!efi_enabled(EFI_BOOT)) {
	272	pr_info("EFI services will not be available.\n");
	273	return -1;
	274	}
	275
6632210f DY	276	if (efi_runtime_disabled()) {
	277	pr_info("EFI runtime services will be disabled.\n");
	278	return -1;
	279	}
	280
	281	pr_info("Remapping and enabling EFI services.\n");
7fe5d2b1 AB	282
7fe5d2b1 AB	283	mapsize = memmap.map_end - memmap.map;
f84d0275 MS	284	memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
f84d0275 MS	285	mapsize);
7fe5d2b1 AB	286	if (!memmap.map) {
	287	pr_err("Failed to remap EFI memory map\n");
	288	return -1;
	289	}
f84d0275	290	memmap.map_end = memmap.map + mapsize;
f84d0275 MS	291	efi.memmap = &memmap;
f84d0275 MS	292
f3cdfd23 AB	293	efi.systab = (__force void *)ioremap_cache(efi_system_table,
f3cdfd23 AB	294	sizeof(efi_system_table_t));
99a5603e	295	if (!efi.systab) {
f3cdfd23 AB	296	pr_err("Failed to remap EFI System Table\n");
f3cdfd23 AB	297	return -1;
99a5603e AB	298	}
99a5603e AB	299	set_bit(EFI_SYSTEM_TABLES, &efi.flags);
f84d0275	300
60305db9	301	if (!efi_virtmap_init()) {
f3cdfd23	302	pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
f84d0275 MS	303	return -1;
	304	}
	305
	306	/* Set up runtime services function pointers */
e15dd494	307	efi_native_runtime_setup();
f84d0275 MS	308	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
f84d0275 MS	309
6a7519e8 SP	310	efi.runtime_version = efi.systab->hdr.revision;
6a7519e8 SP	311
f84d0275 MS	312	return 0;
f84d0275 MS	313	}
f3cdfd23	314	early_initcall(arm64_enable_runtime_services);
d1ae8c00 YL	315
	316	static int __init arm64_dmi_init(void)
	317	{
	318	/*
	319	* On arm64, DMI depends on UEFI, and dmi_scan_machine() needs to
	320	* be called early because dmi_id_init(), which is an arch_initcall
	321	* itself, depends on dmi_scan_machine() having been called already.
	322	*/
	323	dmi_scan_machine();
b07bfaa3 AB	324	if (dmi_available)
b07bfaa3 AB	325	dmi_set_dump_stack_arch_desc();
d1ae8c00 YL	326	return 0;
	327	}
	328	core_initcall(arm64_dmi_init);
f3cdfd23	329
f3cdfd23 AB	330	static void efi_set_pgd(struct mm_struct *mm)
f3cdfd23 AB	331	{
130c93fd WD	332	if (mm == &init_mm)
	333	cpu_set_reserved_ttbr0();
	334	else
	335	cpu_switch_mm(mm->pgd, mm);
	336
f3cdfd23 AB	337	flush_tlb_all();
	338	if (icache_is_aivivt())
	339	__flush_icache_all();
	340	}
	341
	342	void efi_virtmap_load(void)
	343	{
	344	preempt_disable();
	345	efi_set_pgd(&efi_mm);
	346	}
	347
	348	void efi_virtmap_unload(void)
	349	{
	350	efi_set_pgd(current->active_mm);
	351	preempt_enable();
	352	}
60c0d45a AB	353
	354	/*
	355	* UpdateCapsule() depends on the system being shutdown via
	356	* ResetSystem().
	357	*/
	358	bool efi_poweroff_required(void)
	359	{
	360	return efi_enabled(EFI_RUNTIME_SERVICES);
	361	}