text: /*
   * x86_64 specific EFI support functions
   * Based on Extensible Firmware Interface Specification version 1.0
   *
   * 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>
   *
   * Code to convert EFI to E820 map has been implemented in elilo bootloader
   * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
   * is setup appropriately for EFI runtime code.
   * - mouli 06/14/2007.
   *
   */
  
  #define pr_fmt(fmt) "efi: " fmt
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/mm.h>
  #include <linux/types.h>
  #include <linux/spinlock.h>
  #include <linux/bootmem.h>
  #include <linux/ioport.h>
  #include <linux/init.h>
  #include <linux/mc146818rtc.h>
  #include <linux/efi.h>
  #include <linux/uaccess.h>
  #include <linux/io.h>
  #include <linux/reboot.h>
  #include <linux/slab.h>
  #include <linux/ucs2_string.h>
  
  #include <asm/setup.h>
  #include <asm/page.h>
  #include <asm/e820.h>
  #include <asm/pgtable.h>
  #include <asm/tlbflush.h>
  #include <asm/proto.h>
  #include <asm/efi.h>
  #include <asm/cacheflush.h>
  #include <asm/fixmap.h>
  #include <asm/realmode.h>
  #include <asm/time.h>
  #include <asm/pgalloc.h>
  #include <asm/sections.h>
  
  /*
   * We allocate runtime services regions bottom-up, starting from -4G, i.e.
   * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
   */
  static u64 efi_va = EFI_VA_START;
  
  struct efi_scratch efi_scratch;
  
  static void __init early_code_mapping_set_exec(int executable)
  {
  	efi_memory_desc_t *md;
  
  	if (!(__supported_pte_mask & _PAGE_NX))
  		return;
  
  	/* Make EFI service code area executable */
  	for_each_efi_memory_desc(md) {
  		if (md->type == EFI_RUNTIME_SERVICES_CODE ||
  		    md->type == EFI_BOOT_SERVICES_CODE)
  			efi_set_executable(md, executable);
  	}
  }
  
  pgd_t * __init efi_call_phys_prolog(void)
  {
  	unsigned long vaddress;
  	pgd_t *save_pgd;
  
  	int pgd;
  	int n_pgds;
  
  	if (!efi_enabled(EFI_OLD_MEMMAP)) {
  		save_pgd = (pgd_t *)read_cr3();
  		write_cr3((unsigned long)efi_scratch.efi_pgt);
  		goto out;
  	}
  
  	early_code_mapping_set_exec(1);
  
  	n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
  	save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL);
  
  	for (pgd = 0; pgd < n_pgds; pgd++) {
  		save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE);
  		vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
  		set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
  	}
  out:
  	__flush_tlb_all();
  
  	return save_pgd;
  }
  
  void __init efi_call_phys_epilog(pgd_t *save_pgd)
  {
  	/*
  	 * After the lock is released, the original page table is restored.
  	 */
  	int pgd_idx;
  	int nr_pgds;
  
  	if (!efi_enabled(EFI_OLD_MEMMAP)) {
  		write_cr3((unsigned long)save_pgd);
  		__flush_tlb_all();
  		return;
  	}
  
  	nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
  
  	for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++)
  		set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
  
  	kfree(save_pgd);
  
  	__flush_tlb_all();
  	early_code_mapping_set_exec(0);
  }
  
  static pgd_t *efi_pgd;
  
  /*
   * We need our own copy of the higher levels of the page tables
   * because we want to avoid inserting EFI region mappings (EFI_VA_END
   * to EFI_VA_START) into the standard kernel page tables. Everything
   * else can be shared, see efi_sync_low_kernel_mappings().
   */
  int __init efi_alloc_page_tables(void)
  {
  	pgd_t *pgd;
  	pud_t *pud;
  	gfp_t gfp_mask;
  
  	if (efi_enabled(EFI_OLD_MEMMAP))
  		return 0;
  
  	gfp_mask = GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO;
  	efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
  	if (!efi_pgd)
  		return -ENOMEM;
  
  	pgd = efi_pgd + pgd_index(EFI_VA_END);
  
  	pud = pud_alloc_one(NULL, 0);
  	if (!pud) {
  		free_page((unsigned long)efi_pgd);
  		return -ENOMEM;
  	}
  
  	pgd_populate(NULL, pgd, pud);
  
  	return 0;
  }
  
  /*
   * Add low kernel mappings for passing arguments to EFI functions.
   */
  void efi_sync_low_kernel_mappings(void)
  {
  	unsigned num_entries;
  	pgd_t *pgd_k, *pgd_efi;
  	pud_t *pud_k, *pud_efi;
  
  	if (efi_enabled(EFI_OLD_MEMMAP))
  		return;
  
  	/*
  	 * We can share all PGD entries apart from the one entry that
  	 * covers the EFI runtime mapping space.
  	 *
  	 * Make sure the EFI runtime region mappings are guaranteed to
  	 * only span a single PGD entry and that the entry also maps
  	 * other important kernel regions.
  	 */
  	BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
  	BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
  			(EFI_VA_END & PGDIR_MASK));
  
  	pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
  	pgd_k = pgd_offset_k(PAGE_OFFSET);
  
  	num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
  	memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
  
  	/*
  	 * We share all the PUD entries apart from those that map the
  	 * EFI regions. Copy around them.
  	 */
  	BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
  	BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
  
  	pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
  	pud_efi = pud_offset(pgd_efi, 0);
  
  	pgd_k = pgd_offset_k(EFI_VA_END);
  	pud_k = pud_offset(pgd_k, 0);
  
  	num_entries = pud_index(EFI_VA_END);
  	memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
  
  	pud_efi = pud_offset(pgd_efi, EFI_VA_START);
  	pud_k = pud_offset(pgd_k, EFI_VA_START);
  
  	num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
  	memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
  }
  
  /*
   * Wrapper for slow_virt_to_phys() that handles NULL addresses.
   */
  static inline phys_addr_t
  virt_to_phys_or_null_size(void *va, unsigned long size)
  {
  	bool bad_size;
  
  	if (!va)
  		return 0;
  
  	if (virt_addr_valid(va))
  		return virt_to_phys(va);
  
  	/*
  	 * A fully aligned variable on the stack is guaranteed not to
  	 * cross a page bounary. Try to catch strings on the stack by
  	 * checking that 'size' is a power of two.
  	 */
  	bad_size = size > PAGE_SIZE || !is_power_of_2(size);
  
  	WARN_ON(!IS_ALIGNED((unsigned long)va, size) || bad_size);
  
  	return slow_virt_to_phys(va);
  }
  
  #define virt_to_phys_or_null(addr)				\
  	virt_to_phys_or_null_size((addr), sizeof(*(addr)))
  
  int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
  {
  	unsigned long pfn, text;
  	struct page *page;
  	unsigned npages;
  	pgd_t *pgd;
  
  	if (efi_enabled(EFI_OLD_MEMMAP))
  		return 0;
  
  	efi_scratch.efi_pgt = (pgd_t *)__pa(efi_pgd);
  	pgd = efi_pgd;
  
  	/*
  	 * It can happen that the physical address of new_memmap lands in memory
  	 * which is not mapped in the EFI page table. Therefore we need to go
  	 * and ident-map those pages containing the map before calling
  	 * phys_efi_set_virtual_address_map().
  	 */
  	pfn = pa_memmap >> PAGE_SHIFT;
  	if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, _PAGE_NX | _PAGE_RW)) {
  		pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
  		return 1;
  	}
  
  	efi_scratch.use_pgd = true;
  
  	/*
  	 * Certain firmware versions are way too sentimential and still believe
  	 * they are exclusive and unquestionable owners of the first physical page,
  	 * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
  	 * (but then write-access it later during SetVirtualAddressMap()).
  	 *
  	 * Create a 1:1 mapping for this page, to avoid triple faults during early
  	 * boot with such firmware. We are free to hand this page to the BIOS,
  	 * as trim_bios_range() will reserve the first page and isolate it away
  	 * from memory allocators anyway.
  	 */
  	if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, _PAGE_RW)) {
  		pr_err("Failed to create 1:1 mapping for the first page!\n");
  		return 1;
  	}
  
  	/*
  	 * When making calls to the firmware everything needs to be 1:1
  	 * mapped and addressable with 32-bit pointers. Map the kernel
  	 * text and allocate a new stack because we can't rely on the
  	 * stack pointer being < 4GB.
  	 */
  	if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
  		return 0;
  
  	page = alloc_page(GFP_KERNEL|__GFP_DMA32);
  	if (!page)
  		panic("Unable to allocate EFI runtime stack < 4GB\n");
  
  	efi_scratch.phys_stack = virt_to_phys(page_address(page));
  	efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
  
  	npages = (_etext - _text) >> PAGE_SHIFT;
  	text = __pa(_text);
  	pfn = text >> PAGE_SHIFT;
  
  	if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, _PAGE_RW)) {
  		pr_err("Failed to map kernel text 1:1\n");
  		return 1;
  	}
  
  	return 0;
  }
  
  static void __init __map_region(efi_memory_desc_t *md, u64 va)
  {
  	unsigned long flags = _PAGE_RW;
  	unsigned long pfn;
  	pgd_t *pgd = efi_pgd;
  
  	if (!(md->attribute & EFI_MEMORY_WB))
  		flags |= _PAGE_PCD;
  
  	pfn = md->phys_addr >> PAGE_SHIFT;
  	if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
  		pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
  			   md->phys_addr, va);
  }
  
  void __init efi_map_region(efi_memory_desc_t *md)
  {
  	unsigned long size = md->num_pages << PAGE_SHIFT;
  	u64 pa = md->phys_addr;
  
  	if (efi_enabled(EFI_OLD_MEMMAP))
  		return old_map_region(md);
  
  	/*
  	 * Make sure the 1:1 mappings are present as a catch-all for b0rked
  	 * firmware which doesn't update all internal pointers after switching
  	 * to virtual mode and would otherwise crap on us.
  	 */
  	__map_region(md, md->phys_addr);
  
  	/*
  	 * Enforce the 1:1 mapping as the default virtual address when
  	 * booting in EFI mixed mode, because even though we may be
  	 * running a 64-bit kernel, the firmware may only be 32-bit.
  	 */
  	if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
  		md->virt_addr = md->phys_addr;
  		return;
  	}
  
  	efi_va -= size;
  
  	/* Is PA 2M-aligned? */
  	if (!(pa & (PMD_SIZE - 1))) {
  		efi_va &= PMD_MASK;
  	} else {
  		u64 pa_offset = pa & (PMD_SIZE - 1);
  		u64 prev_va = efi_va;
  
  		/* get us the same offset within this 2M page */
  		efi_va = (efi_va & PMD_MASK) + pa_offset;
  
  		if (efi_va > prev_va)
  			efi_va -= PMD_SIZE;
  	}
  
  	if (efi_va < EFI_VA_END) {
  		pr_warn(FW_WARN "VA address range overflow!\n");
  		return;
  	}
  
  	/* Do the VA map */
  	__map_region(md, efi_va);
  	md->virt_addr = efi_va;
  }
  
  /*
   * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
   * md->virt_addr is the original virtual address which had been mapped in kexec
   * 1st kernel.
   */
  void __init efi_map_region_fixed(efi_memory_desc_t *md)
  {
  	__map_region(md, md->phys_addr);
  	__map_region(md, md->virt_addr);
  }
  
  void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
  				 u32 type, u64 attribute)
  {
  	unsigned long last_map_pfn;
  
  	if (type == EFI_MEMORY_MAPPED_IO)
  		return ioremap(phys_addr, size);
  
  	last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
  	if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
  		unsigned long top = last_map_pfn << PAGE_SHIFT;
  		efi_ioremap(top, size - (top - phys_addr), type, attribute);
  	}
  
  	if (!(attribute & EFI_MEMORY_WB))
  		efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
  
  	return (void __iomem *)__va(phys_addr);
  }
  
  void __init parse_efi_setup(u64 phys_addr, u32 data_len)
  {
  	efi_setup = phys_addr + sizeof(struct setup_data);
  }
  
  void __init efi_runtime_update_mappings(void)
  {
  	unsigned long pfn;
  	pgd_t *pgd = efi_pgd;
  	efi_memory_desc_t *md;
  
  	if (efi_enabled(EFI_OLD_MEMMAP)) {
  		if (__supported_pte_mask & _PAGE_NX)
  			runtime_code_page_mkexec();
  		return;
  	}
  
  	if (!efi_enabled(EFI_NX_PE_DATA))
  		return;
  
  	for_each_efi_memory_desc(md) {
  		unsigned long pf = 0;
  
  		if (!(md->attribute & EFI_MEMORY_RUNTIME))
  			continue;
  
  		if (!(md->attribute & EFI_MEMORY_WB))
  			pf |= _PAGE_PCD;
  
  		if ((md->attribute & EFI_MEMORY_XP) ||
  			(md->type == EFI_RUNTIME_SERVICES_DATA))
  			pf |= _PAGE_NX;
  
  		if (!(md->attribute & EFI_MEMORY_RO) &&
  			(md->type != EFI_RUNTIME_SERVICES_CODE))
  			pf |= _PAGE_RW;
  
  		/* Update the 1:1 mapping */
  		pfn = md->phys_addr >> PAGE_SHIFT;
  		if (kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf))
  			pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
  				   md->phys_addr, md->virt_addr);
  
  		if (kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf))
  			pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
  				   md->phys_addr, md->virt_addr);
  	}
  }
  
  void __init efi_dump_pagetable(void)
  {
  #ifdef CONFIG_EFI_PGT_DUMP
  	ptdump_walk_pgd_level(NULL, efi_pgd);
  #endif
  }
  
  #ifdef CONFIG_EFI_MIXED
  extern efi_status_t efi64_thunk(u32, ...);
  
  #define runtime_service32(func)						 \
  ({									 \
  	u32 table = (u32)(unsigned long)efi.systab;			 \
  	u32 *rt, *___f;							 \
  									 \
  	rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime));	 \
  	___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
  	*___f;								 \
  })
  
  /*
   * Switch to the EFI page tables early so that we can access the 1:1
   * runtime services mappings which are not mapped in any other page
   * tables. This function must be called before runtime_service32().
   *
   * Also, disable interrupts because the IDT points to 64-bit handlers,
   * which aren't going to function correctly when we switch to 32-bit.
   */
  #define efi_thunk(f, ...)						\
  ({									\
  	efi_status_t __s;						\
  	unsigned long __flags;						\
  	u32 __func;							\
  									\
  	local_irq_save(__flags);					\
  	arch_efi_call_virt_setup();					\
  									\
  	__func = runtime_service32(f);					\
  	__s = efi64_thunk(__func, __VA_ARGS__);				\
  									\
  	arch_efi_call_virt_teardown();					\
  	local_irq_restore(__flags);					\
  									\
  	__s;								\
  })
  
  efi_status_t efi_thunk_set_virtual_address_map(
  	void *phys_set_virtual_address_map,
  	unsigned long memory_map_size,
  	unsigned long descriptor_size,
  	u32 descriptor_version,
  	efi_memory_desc_t *virtual_map)
  {
  	efi_status_t status;
  	unsigned long flags;
  	u32 func;
  
  	efi_sync_low_kernel_mappings();
  	local_irq_save(flags);
  
  	efi_scratch.prev_cr3 = read_cr3();
  	write_cr3((unsigned long)efi_scratch.efi_pgt);
  	__flush_tlb_all();
  
  	func = (u32)(unsigned long)phys_set_virtual_address_map;
  	status = efi64_thunk(func, memory_map_size, descriptor_size,
  			     descriptor_version, virtual_map);
  
  	write_cr3(efi_scratch.prev_cr3);
  	__flush_tlb_all();
  	local_irq_restore(flags);
  
  	return status;
  }
  
  static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
  {
  	efi_status_t status;
  	u32 phys_tm, phys_tc;
  
  	spin_lock(&rtc_lock);
  
  	phys_tm = virt_to_phys_or_null(tm);
  	phys_tc = virt_to_phys_or_null(tc);
  
  	status = efi_thunk(get_time, phys_tm, phys_tc);
  
  	spin_unlock(&rtc_lock);
  
  	return status;
  }
  
  static efi_status_t efi_thunk_set_time(efi_time_t *tm)
  {
  	efi_status_t status;
  	u32 phys_tm;
  
  	spin_lock(&rtc_lock);
  
  	phys_tm = virt_to_phys_or_null(tm);
  
  	status = efi_thunk(set_time, phys_tm);
  
  	spin_unlock(&rtc_lock);
  
  	return status;
  }
  
  static efi_status_t
  efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
  			  efi_time_t *tm)
  {
  	efi_status_t status;
  	u32 phys_enabled, phys_pending, phys_tm;
  
  	spin_lock(&rtc_lock);
  
  	phys_enabled = virt_to_phys_or_null(enabled);
  	phys_pending = virt_to_phys_or_null(pending);
  	phys_tm = virt_to_phys_or_null(tm);
  
  	status = efi_thunk(get_wakeup_time, phys_enabled,
  			     phys_pending, phys_tm);
  
  	spin_unlock(&rtc_lock);
  
  	return status;
  }
  
  static efi_status_t
  efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
  {
  	efi_status_t status;
  	u32 phys_tm;
  
  	spin_lock(&rtc_lock);
  
  	phys_tm = virt_to_phys_or_null(tm);
  
  	status = efi_thunk(set_wakeup_time, enabled, phys_tm);
  
  	spin_unlock(&rtc_lock);
  
  	return status;
  }
  
  static unsigned long efi_name_size(efi_char16_t *name)
  {
  	return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
  }
  
  static efi_status_t
  efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
  		       u32 *attr, unsigned long *data_size, void *data)
  {
  	efi_status_t status;
  	u32 phys_name, phys_vendor, phys_attr;
  	u32 phys_data_size, phys_data;
  
  	phys_data_size = virt_to_phys_or_null(data_size);
  	phys_vendor = virt_to_phys_or_null(vendor);
  	phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
  	phys_attr = virt_to_phys_or_null(attr);
  	phys_data = virt_to_phys_or_null_size(data, *data_size);
  
  	status = efi_thunk(get_variable, phys_name, phys_vendor,
  			   phys_attr, phys_data_size, phys_data);
  
  	return status;
  }
  
  static efi_status_t
  efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
  		       u32 attr, unsigned long data_size, void *data)
  {
  	u32 phys_name, phys_vendor, phys_data;
  	efi_status_t status;
  
  	phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
  	phys_vendor = virt_to_phys_or_null(vendor);
  	phys_data = virt_to_phys_or_null_size(data, data_size);
  
  	/* If data_size is > sizeof(u32) we've got problems */
  	status = efi_thunk(set_variable, phys_name, phys_vendor,
  			   attr, data_size, phys_data);
  
  	return status;
  }
  
  static efi_status_t
  efi_thunk_get_next_variable(unsigned long *name_size,
  			    efi_char16_t *name,
  			    efi_guid_t *vendor)
  {
  	efi_status_t status;
  	u32 phys_name_size, phys_name, phys_vendor;
  
  	phys_name_size = virt_to_phys_or_null(name_size);
  	phys_vendor = virt_to_phys_or_null(vendor);
  	phys_name = virt_to_phys_or_null_size(name, *name_size);
  
  	status = efi_thunk(get_next_variable, phys_name_size,
  			   phys_name, phys_vendor);
  
  	return status;
  }
  
  static efi_status_t
  efi_thunk_get_next_high_mono_count(u32 *count)
  {
  	efi_status_t status;
  	u32 phys_count;
  
  	phys_count = virt_to_phys_or_null(count);
  	status = efi_thunk(get_next_high_mono_count, phys_count);
  
  	return status;
  }
  
  static void
  efi_thunk_reset_system(int reset_type, efi_status_t status,
  		       unsigned long data_size, efi_char16_t *data)
  {
  	u32 phys_data;
  
  	phys_data = virt_to_phys_or_null_size(data, data_size);
  
  	efi_thunk(reset_system, reset_type, status, data_size, phys_data);
  }
  
  static efi_status_t
  efi_thunk_update_capsule(efi_capsule_header_t **capsules,
  			 unsigned long count, unsigned long sg_list)
  {
  	/*
  	 * To properly support this function we would need to repackage
  	 * 'capsules' because the firmware doesn't understand 64-bit
  	 * pointers.
  	 */
  	return EFI_UNSUPPORTED;
  }
  
  static efi_status_t
  efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
  			      u64 *remaining_space,
  			      u64 *max_variable_size)
  {
  	efi_status_t status;
  	u32 phys_storage, phys_remaining, phys_max;
  
  	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
  		return EFI_UNSUPPORTED;
  
  	phys_storage = virt_to_phys_or_null(storage_space);
  	phys_remaining = virt_to_phys_or_null(remaining_space);
  	phys_max = virt_to_phys_or_null(max_variable_size);
  
  	status = efi_thunk(query_variable_info, attr, phys_storage,
  			   phys_remaining, phys_max);
  
  	return status;
  }
  
  static efi_status_t
  efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
  			     unsigned long count, u64 *max_size,
  			     int *reset_type)
  {
  	/*
  	 * To properly support this function we would need to repackage
  	 * 'capsules' because the firmware doesn't understand 64-bit
  	 * pointers.
  	 */
  	return EFI_UNSUPPORTED;
  }
  
  void efi_thunk_runtime_setup(void)
  {
  	efi.get_time = efi_thunk_get_time;
  	efi.set_time = efi_thunk_set_time;
  	efi.get_wakeup_time = efi_thunk_get_wakeup_time;
  	efi.set_wakeup_time = efi_thunk_set_wakeup_time;
  	efi.get_variable = efi_thunk_get_variable;
  	efi.get_next_variable = efi_thunk_get_next_variable;
  	efi.set_variable = efi_thunk_set_variable;
  	efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
  	efi.reset_system = efi_thunk_reset_system;
  	efi.query_variable_info = efi_thunk_query_variable_info;
  	efi.update_capsule = efi_thunk_update_capsule;
  	efi.query_capsule_caps = efi_thunk_query_capsule_caps;
  }
  #endif /* CONFIG_EFI_MIXED */
  