[linux-block.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 uefi_debug __initdata;
static int __init uefi_debug_setup(char *str)
{
	uefi_debug = 1;

	return 0;
}
early_param("uefi_debug", uefi_debug_setup);

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));
	if (c16) {
		for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
			vendor[i] = c16[i];
		vendor[i] = '\0';
		early_memunmap(c16, sizeof(vendor));
	}

	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:
		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 (uefi_debug)
		pr_info("Processing EFI memory map:\n");

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

		if (uefi_debug) {
			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 (uefi_debug)
				pr_cont("*");
		}

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