[linux-2.6-block.git] / drivers / firmware / efi / arm-runtime.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/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;

static struct mm_struct efi_mm = {
	.mm_rb			= RB_ROOT,
	.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),
};

#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
#include <asm/ptdump.h>

static struct ptdump_info efi_ptdump_info = {
	.mm		= &efi_mm,
	.markers	= (struct addr_marker[]){
		{ 0,		"UEFI runtime start" },
		{ TASK_SIZE_64,	"UEFI runtime end" }
	},
	.base_addr	= 0,
};

static int __init ptdump_init(void)
{
	return ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");
}
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_info("  EFI remap %pa => %p\n",
				&phys, (void *)(unsigned long)md->virt_addr);
		} else {
			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;
	}

	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");

	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 -ENOMEM;
	}

	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_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(arm_dmi_init);
Commit	Line	Data
e5bc22a4 AB	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
bb817bef	14	#include <linux/dmi.h>
e5bc22a4	15	#include <linux/efi.h>
f7d92489	16	#include <linux/io.h>
e5bc22a4 AB	17	#include <linux/memblock.h>
	18	#include <linux/mm_types.h>
	19	#include <linux/preempt.h>
	20	#include <linux/rbtree.h>
	21	#include <linux/rwsem.h>
	22	#include <linux/sched.h>
	23	#include <linux/slab.h>
	24	#include <linux/spinlock.h>
	25
	26	#include <asm/cacheflush.h>
	27	#include <asm/efi.h>
e5bc22a4	28	#include <asm/mmu.h>
f7d92489	29	#include <asm/pgalloc.h>
e5bc22a4 AB	30	#include <asm/pgtable.h>
e5bc22a4 AB	31
e5bc22a4 AB	32	extern u64 efi_system_table;
	33
	34	static struct mm_struct efi_mm = {
	35	.mm_rb = RB_ROOT,
e5bc22a4 AB	36	.mm_users = ATOMIC_INIT(2),
	37	.mm_count = ATOMIC_INIT(1),
	38	.mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
	39	.page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
	40	.mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
	41	};
	42
4ddb9bf8	43	#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
9d80448a AB	44	#include <asm/ptdump.h>
	45
	46	static struct ptdump_info efi_ptdump_info = {
	47	.mm = &efi_mm,
	48	.markers = (struct addr_marker[]){
	49	{ 0, "UEFI runtime start" },
	50	{ TASK_SIZE_64, "UEFI runtime end" }
	51	},
	52	.base_addr = 0,
	53	};
	54
	55	static int __init ptdump_init(void)
	56	{
4ddb9bf8	57	return ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");
9d80448a AB	58	}
	59	device_initcall(ptdump_init);
	60
	61	#endif
	62
e5bc22a4 AB	63	static bool __init efi_virtmap_init(void)
	64	{
	65	efi_memory_desc_t *md;
14c43be6	66	bool systab_found;
e5bc22a4	67
f7d92489	68	efi_mm.pgd = pgd_alloc(&efi_mm);
d1eb9814	69	mm_init_cpumask(&efi_mm);
e5bc22a4 AB	70	init_new_context(NULL, &efi_mm);
e5bc22a4 AB	71
14c43be6	72	systab_found = false;
78ce248f	73	for_each_efi_memory_desc(md) {
f7d92489 AB	74	phys_addr_t phys = md->phys_addr;
f7d92489 AB	75	int ret;
e5bc22a4 AB	76
	77	if (!(md->attribute & EFI_MEMORY_RUNTIME))
	78	continue;
	79	if (md->virt_addr == 0)
	80	return false;
	81
f7d92489 AB	82	ret = efi_create_mapping(&efi_mm, md);
	83	if (!ret) {
	84	pr_info(" EFI remap %pa => %p\n",
	85	&phys, (void *)(unsigned long)md->virt_addr);
	86	} else {
	87	pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
	88	&phys, ret);
	89	return false;
	90	}
14c43be6 AB	91	/*
	92	* If this entry covers the address of the UEFI system table,
	93	* calculate and record its virtual address.
	94	*/
	95	if (efi_system_table >= phys &&
	96	efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) {
	97	efi.systab = (void *)(unsigned long)(efi_system_table -
	98	phys + md->virt_addr);
	99	systab_found = true;
	100	}
e5bc22a4	101	}
789957ef	102	if (!systab_found) {
14c43be6	103	pr_err("No virtual mapping found for the UEFI System Table\n");
789957ef AB	104	return false;
	105	}
	106
	107	if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
	108	return false;
	109
	110	return true;
e5bc22a4 AB	111	}
	112
	113	/*
	114	* Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
	115	* non-early mapping of the UEFI system table and virtual mappings for all
	116	* EFI_MEMORY_RUNTIME regions.
	117	*/
f7d92489	118	static int __init arm_enable_runtime_services(void)
e5bc22a4 AB	119	{
	120	u64 mapsize;
	121
	122	if (!efi_enabled(EFI_BOOT)) {
	123	pr_info("EFI services will not be available.\n");
	124	return 0;
	125	}
	126
	127	if (efi_runtime_disabled()) {
	128	pr_info("EFI runtime services will be disabled.\n");
	129	return 0;
	130	}
	131
0cac5c30 SZ	132	if (efi_enabled(EFI_RUNTIME_SERVICES)) {
	133	pr_info("EFI runtime services access via paravirt.\n");
	134	return 0;
	135	}
	136
e5bc22a4 AB	137	pr_info("Remapping and enabling EFI services.\n");
e5bc22a4 AB	138
9479c7ce	139	mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
884f4f66	140
dca0f971	141	if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
e5bc22a4 AB	142	pr_err("Failed to remap EFI memory map\n");
	143	return -ENOMEM;
	144	}
e5bc22a4	145
e5bc22a4	146	if (!efi_virtmap_init()) {
14c43be6	147	pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
e5bc22a4 AB	148	return -ENOMEM;
	149	}
	150
	151	/* Set up runtime services function pointers */
	152	efi_native_runtime_setup();
	153	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
	154
e5bc22a4 AB	155	return 0;
e5bc22a4 AB	156	}
f7d92489	157	early_initcall(arm_enable_runtime_services);
e5bc22a4 AB	158
	159	void efi_virtmap_load(void)
	160	{
	161	preempt_disable();
	162	efi_set_pgd(&efi_mm);
	163	}
	164
	165	void efi_virtmap_unload(void)
	166	{
	167	efi_set_pgd(current->active_mm);
	168	preempt_enable();
	169	}
bb817bef AB	170
	171
	172	static int __init arm_dmi_init(void)
	173	{
	174	/*
	175	* On arm64/ARM, DMI depends on UEFI, and dmi_scan_machine() needs to
	176	* be called early because dmi_id_init(), which is an arch_initcall
	177	* itself, depends on dmi_scan_machine() having been called already.
	178	*/
	179	dmi_scan_machine();
	180	if (dmi_available)
	181	dmi_set_dump_stack_arch_desc();
	182	return 0;
	183	}
	184	core_initcall(arm_dmi_init);