path: root/arch/x86/platform/efi/efi.c

/*
 * Common EFI (Extensible Firmware Interface) support functions
 * Based on Extensible Firmware Interface Specification version 1.0
 *
 * Copyright (C) 1999 VA Linux Systems
 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
 * Copyright (C) 1999-2002 Hewlett-Packard Co.
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 *	Stephane Eranian <eranian@hpl.hp.com>
 * Copyright (C) 2005-2008 Intel Co.
 *	Fenghua Yu <fenghua.yu@intel.com>
 *	Bibo Mao <bibo.mao@intel.com>
 *	Chandramouli Narayanan <mouli@linux.intel.com>
 *	Huang Ying <ying.huang@intel.com>
 *
 * Copied from efi_32.c to eliminate the duplicated code between EFI
 * 32/64 support code. --ying 2007-10-26
 *
 * All EFI Runtime Services are not implemented yet as EFI only
 * supports physical mode addressing on SoftSDV. This is to be fixed
 * in a future version.  --drummond 1999-07-20
 *
 * Implemented EFI runtime services and virtual mode calls.  --davidm
 *
 * Goutham Rao: <goutham.rao@intel.com>
 *	Skip non-WB memory and ignore empty memory ranges.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/efi.h>
#include <linux/efi-bgrt.h>
#include <linux/export.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/time.h>
#include <linux/io.h>
#include <linux/reboot.h>
#include <linux/bcd.h>

#include <asm/setup.h>
#include <asm/efi.h>
#include <asm/time.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/x86_init.h>

#define EFI_DEBUG	1

struct efi __read_mostly efi = {
	.mps        = EFI_INVALID_TABLE_ADDR,
	.acpi       = EFI_INVALID_TABLE_ADDR,
	.acpi20     = EFI_INVALID_TABLE_ADDR,
	.smbios     = EFI_INVALID_TABLE_ADDR,
	.sal_systab = EFI_INVALID_TABLE_ADDR,
	.boot_info  = EFI_INVALID_TABLE_ADDR,
	.hcdp       = EFI_INVALID_TABLE_ADDR,
	.uga        = EFI_INVALID_TABLE_ADDR,
	.uv_systab  = EFI_INVALID_TABLE_ADDR,
};
EXPORT_SYMBOL(efi);

struct efi_memory_map memmap;

static struct efi efi_phys __initdata;
static efi_system_table_t efi_systab __initdata;

static inline bool efi_is_native(void)
{
	return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
}

unsigned long x86_efi_facility;

/*
 * Returns 1 if 'facility' is enabled, 0 otherwise.
 */
int efi_enabled(int facility)
{
	return test_bit(facility, &x86_efi_facility) != 0;
}
EXPORT_SYMBOL(efi_enabled);

static bool disable_runtime = false;
static int __init setup_noefi(char *arg)
{
	disable_runtime = true;
	return 0;
}
early_param("noefi", setup_noefi);

int add_efi_memmap;
EXPORT_SYMBOL(add_efi_memmap);

static int __init setup_add_efi_memmap(char *arg)
{
	add_efi_memmap = 1;
	return 0;
}
early_param("add_efi_memmap", setup_add_efi_memmap);


static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
	unsigned long flags;
	efi_status_t status;

	spin_lock_irqsave(&rtc_lock, flags);
	status = efi_call_virt2(get_time, tm, tc);
	spin_unlock_irqrestore(&rtc_lock, flags);
	return status;
}

static efi_status_t virt_efi_set_time(efi_time_t *tm)
{
	unsigned long flags;
	efi_status_t status;

	spin_lock_irqsave(&rtc_lock, flags);
	status = efi_call_virt1(set_time, tm);
	spin_unlock_irqrestore(&rtc_lock, flags);
	return status;
}

static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
					     efi_bool_t *pending,
					     efi_time_t *tm)
{
	unsigned long flags;
	efi_status_t status;

	spin_lock_irqsave(&rtc_lock, flags);
	status = efi_call_virt3(get_wakeup_time,
				enabled, pending, tm);
	spin_unlock_irqrestore(&rtc_lock, flags);
	return status;
}

static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
{
	unsigned long flags;
	efi_status_t status;

	spin_lock_irqsave(&rtc_lock, flags);
	status = efi_call_virt2(set_wakeup_time,
				enabled, tm);
	spin_unlock_irqrestore(&rtc_lock, flags);
	return status;
}

static efi_status_t virt_efi_get_variable(efi_char16_t *name,
					  efi_guid_t *vendor,
					  u32 *attr,
					  unsigned long *data_size,
					  void *data)
{
	return efi_call_virt5(get_variable,
			      name, vendor, attr,
			      data_size, data);
}

static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
					       efi_char16_t *name,
					       efi_guid_t *vendor)
{
	return efi_call_virt3(get_next_variable,
			      name_size, name, vendor);
}

static efi_status_t virt_efi_set_variable(efi_char16_t *name,
					  efi_guid_t *vendor,
					  u32 attr,
					  unsigned long data_size,
					  void *data)
{
	return efi_call_virt5(set_variable,
			      name,