1 // SPDX-License-Identifier: GPL-2.0
3 * x86_64 specific EFI support functions
4 * Based on Extensible Firmware Interface Specification version 1.0
6 * Copyright (C) 2005-2008 Intel Co.
7 * Fenghua Yu <fenghua.yu@intel.com>
8 * Bibo Mao <bibo.mao@intel.com>
9 * Chandramouli Narayanan <mouli@linux.intel.com>
10 * Huang Ying <ying.huang@intel.com>
12 * Code to convert EFI to E820 map has been implemented in elilo bootloader
13 * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
14 * is setup appropriately for EFI runtime code.
19 #define pr_fmt(fmt) "efi: " fmt
21 #include <linux/kernel.h>
22 #include <linux/init.h>
24 #include <linux/types.h>
25 #include <linux/spinlock.h>
26 #include <linux/memblock.h>
27 #include <linux/ioport.h>
28 #include <linux/mc146818rtc.h>
29 #include <linux/efi.h>
30 #include <linux/export.h>
31 #include <linux/uaccess.h>
33 #include <linux/reboot.h>
34 #include <linux/slab.h>
35 #include <linux/ucs2_string.h>
36 #include <linux/mem_encrypt.h>
37 #include <linux/sched/task.h>
39 #include <asm/setup.h>
41 #include <asm/e820/api.h>
42 #include <asm/tlbflush.h>
43 #include <asm/proto.h>
45 #include <asm/cacheflush.h>
46 #include <asm/fixmap.h>
47 #include <asm/realmode.h>
49 #include <asm/pgalloc.h>
53 * We allocate runtime services regions top-down, starting from -4G, i.e.
54 * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
56 static u64 efi_va = EFI_VA_START;
57 static struct mm_struct *efi_prev_mm;
60 * We need our own copy of the higher levels of the page tables
61 * because we want to avoid inserting EFI region mappings (EFI_VA_END
62 * to EFI_VA_START) into the standard kernel page tables. Everything
63 * else can be shared, see efi_sync_low_kernel_mappings().
65 * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
68 int __init efi_alloc_page_tables(void)
75 gfp_mask = GFP_KERNEL | __GFP_ZERO;
76 efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
80 pgd = efi_pgd + pgd_index(EFI_VA_END);
81 p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
85 pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
90 mm_init_cpumask(&efi_mm);
91 init_new_context(NULL, &efi_mm);
96 if (pgtable_l5_enabled())
97 free_page((unsigned long)pgd_page_vaddr(*pgd));
99 free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
105 * Add low kernel mappings for passing arguments to EFI functions.
107 void efi_sync_low_kernel_mappings(void)
109 unsigned num_entries;
110 pgd_t *pgd_k, *pgd_efi;
111 p4d_t *p4d_k, *p4d_efi;
112 pud_t *pud_k, *pud_efi;
113 pgd_t *efi_pgd = efi_mm.pgd;
115 pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
116 pgd_k = pgd_offset_k(PAGE_OFFSET);
118 num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
119 memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
121 pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
122 pgd_k = pgd_offset_k(EFI_VA_END);
123 p4d_efi = p4d_offset(pgd_efi, 0);
124 p4d_k = p4d_offset(pgd_k, 0);
126 num_entries = p4d_index(EFI_VA_END);
127 memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
130 * We share all the PUD entries apart from those that map the
131 * EFI regions. Copy around them.
133 BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
134 BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
136 p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
137 p4d_k = p4d_offset(pgd_k, EFI_VA_END);
138 pud_efi = pud_offset(p4d_efi, 0);
139 pud_k = pud_offset(p4d_k, 0);
141 num_entries = pud_index(EFI_VA_END);
142 memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
144 pud_efi = pud_offset(p4d_efi, EFI_VA_START);
145 pud_k = pud_offset(p4d_k, EFI_VA_START);
147 num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
148 memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
152 * Wrapper for slow_virt_to_phys() that handles NULL addresses.
154 static inline phys_addr_t
155 virt_to_phys_or_null_size(void *va, unsigned long size)
162 if (virt_addr_valid(va))
163 return virt_to_phys(va);
165 pa = slow_virt_to_phys(va);
167 /* check if the object crosses a page boundary */
168 if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
174 #define virt_to_phys_or_null(addr) \
175 virt_to_phys_or_null_size((addr), sizeof(*(addr)))
177 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
179 unsigned long pfn, text, pf, rodata;
182 pgd_t *pgd = efi_mm.pgd;
185 * It can happen that the physical address of new_memmap lands in memory
186 * which is not mapped in the EFI page table. Therefore we need to go
187 * and ident-map those pages containing the map before calling
188 * phys_efi_set_virtual_address_map().
190 pfn = pa_memmap >> PAGE_SHIFT;
191 pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
192 if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
193 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
198 * Certain firmware versions are way too sentimental and still believe
199 * they are exclusive and unquestionable owners of the first physical page,
200 * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
201 * (but then write-access it later during SetVirtualAddressMap()).
203 * Create a 1:1 mapping for this page, to avoid triple faults during early
204 * boot with such firmware. We are free to hand this page to the BIOS,
205 * as trim_bios_range() will reserve the first page and isolate it away
206 * from memory allocators anyway.
208 if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
209 pr_err("Failed to create 1:1 mapping for the first page!\n");
214 * When SEV-ES is active, the GHCB as set by the kernel will be used
215 * by firmware. Create a 1:1 unencrypted mapping for each GHCB.
217 if (sev_es_efi_map_ghcbs(pgd)) {
218 pr_err("Failed to create 1:1 mapping for the GHCBs!\n");
223 * When making calls to the firmware everything needs to be 1:1
224 * mapped and addressable with 32-bit pointers. Map the kernel
225 * text and allocate a new stack because we can't rely on the
226 * stack pointer being < 4GB.
231 page = alloc_page(GFP_KERNEL|__GFP_DMA32);
233 pr_err("Unable to allocate EFI runtime stack < 4GB\n");
237 efi_mixed_mode_stack_pa = page_to_phys(page + 1); /* stack grows down */
239 npages = (_etext - _text) >> PAGE_SHIFT;
241 pfn = text >> PAGE_SHIFT;
244 if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
245 pr_err("Failed to map kernel text 1:1\n");
249 npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
250 rodata = __pa(__start_rodata);
251 pfn = rodata >> PAGE_SHIFT;
253 pf = _PAGE_NX | _PAGE_ENC;
254 if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
255 pr_err("Failed to map kernel rodata 1:1\n");
262 static void __init __map_region(efi_memory_desc_t *md, u64 va)
264 unsigned long flags = _PAGE_RW;
266 pgd_t *pgd = efi_mm.pgd;
269 * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
270 * executable images in memory that consist of both R-X and
271 * RW- sections, so we cannot apply read-only or non-exec
272 * permissions just yet. However, modern EFI systems provide
273 * a memory attributes table that describes those sections
274 * with the appropriate restricted permissions, which are
275 * applied in efi_runtime_update_mappings() below. All other
276 * regions can be mapped non-executable at this point, with
277 * the exception of boot services code regions, but those will
278 * be unmapped again entirely in efi_free_boot_services().
280 if (md->type != EFI_BOOT_SERVICES_CODE &&
281 md->type != EFI_RUNTIME_SERVICES_CODE)
284 if (!(md->attribute & EFI_MEMORY_WB))
287 if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
290 pfn = md->phys_addr >> PAGE_SHIFT;
291 if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
292 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
296 void __init efi_map_region(efi_memory_desc_t *md)
298 unsigned long size = md->num_pages << PAGE_SHIFT;
299 u64 pa = md->phys_addr;
302 * Make sure the 1:1 mappings are present as a catch-all for b0rked
303 * firmware which doesn't update all internal pointers after switching
304 * to virtual mode and would otherwise crap on us.
306 __map_region(md, md->phys_addr);
309 * Enforce the 1:1 mapping as the default virtual address when
310 * booting in EFI mixed mode, because even though we may be
311 * running a 64-bit kernel, the firmware may only be 32-bit.
313 if (efi_is_mixed()) {
314 md->virt_addr = md->phys_addr;
320 /* Is PA 2M-aligned? */
321 if (!(pa & (PMD_SIZE - 1))) {
324 u64 pa_offset = pa & (PMD_SIZE - 1);
325 u64 prev_va = efi_va;
327 /* get us the same offset within this 2M page */
328 efi_va = (efi_va & PMD_MASK) + pa_offset;
330 if (efi_va > prev_va)
334 if (efi_va < EFI_VA_END) {
335 pr_warn(FW_WARN "VA address range overflow!\n");
340 __map_region(md, efi_va);
341 md->virt_addr = efi_va;
345 * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
346 * md->virt_addr is the original virtual address which had been mapped in kexec
349 void __init efi_map_region_fixed(efi_memory_desc_t *md)
351 __map_region(md, md->phys_addr);
352 __map_region(md, md->virt_addr);
355 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
357 efi_setup = phys_addr + sizeof(struct setup_data);
360 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
363 pgd_t *pgd = efi_mm.pgd;
366 /* Update the 1:1 mapping */
367 pfn = md->phys_addr >> PAGE_SHIFT;
368 err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
370 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
371 md->phys_addr, md->virt_addr);
374 err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
376 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
377 md->phys_addr, md->virt_addr);
383 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
385 unsigned long pf = 0;
387 if (md->attribute & EFI_MEMORY_XP)
390 if (!(md->attribute & EFI_MEMORY_RO))
396 return efi_update_mappings(md, pf);
399 void __init efi_runtime_update_mappings(void)
401 efi_memory_desc_t *md;
404 * Use the EFI Memory Attribute Table for mapping permissions if it
405 * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
407 if (efi_enabled(EFI_MEM_ATTR)) {
408 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
413 * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
414 * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
415 * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
416 * published by the firmware. Even if we find a buggy implementation of
417 * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
418 * EFI_PROPERTIES_TABLE, because of the same reason.
421 if (!efi_enabled(EFI_NX_PE_DATA))
424 for_each_efi_memory_desc(md) {
425 unsigned long pf = 0;
427 if (!(md->attribute & EFI_MEMORY_RUNTIME))
430 if (!(md->attribute & EFI_MEMORY_WB))
433 if ((md->attribute & EFI_MEMORY_XP) ||
434 (md->type == EFI_RUNTIME_SERVICES_DATA))
437 if (!(md->attribute & EFI_MEMORY_RO) &&
438 (md->type != EFI_RUNTIME_SERVICES_CODE))
444 efi_update_mappings(md, pf);
448 void __init efi_dump_pagetable(void)
450 #ifdef CONFIG_EFI_PGT_DUMP
451 ptdump_walk_pgd_level(NULL, &efi_mm);
456 * Makes the calling thread switch to/from efi_mm context. Can be used
457 * in a kernel thread and user context. Preemption needs to remain disabled
458 * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
459 * can not change under us.
460 * It should be ensured that there are no concurrent calls to this function.
462 void efi_enter_mm(void)
464 efi_prev_mm = current->active_mm;
465 current->active_mm = &efi_mm;
466 switch_mm(efi_prev_mm, &efi_mm, NULL);
469 void efi_leave_mm(void)
471 current->active_mm = efi_prev_mm;
472 switch_mm(&efi_mm, efi_prev_mm, NULL);
475 static DEFINE_SPINLOCK(efi_runtime_lock);
478 * DS and ES contain user values. We need to save them.
479 * The 32-bit EFI code needs a valid DS, ES, and SS. There's no
480 * need to save the old SS: __KERNEL_DS is always acceptable.
482 #define __efi_thunk(func, ...) \
484 unsigned short __ds, __es; \
485 efi_status_t ____s; \
487 savesegment(ds, __ds); \
488 savesegment(es, __es); \
490 loadsegment(ss, __KERNEL_DS); \
491 loadsegment(ds, __KERNEL_DS); \
492 loadsegment(es, __KERNEL_DS); \
494 ____s = efi64_thunk(efi.runtime->mixed_mode.func, __VA_ARGS__); \
496 loadsegment(ds, __ds); \
497 loadsegment(es, __es); \
499 ____s ^= (____s & BIT(31)) | (____s & BIT_ULL(31)) << 32; \
504 * Switch to the EFI page tables early so that we can access the 1:1
505 * runtime services mappings which are not mapped in any other page
508 * Also, disable interrupts because the IDT points to 64-bit handlers,
509 * which aren't going to function correctly when we switch to 32-bit.
511 #define efi_thunk(func...) \
515 arch_efi_call_virt_setup(); \
517 __s = __efi_thunk(func); \
519 arch_efi_call_virt_teardown(); \
524 static efi_status_t __init __no_sanitize_address
525 efi_thunk_set_virtual_address_map(unsigned long memory_map_size,
526 unsigned long descriptor_size,
527 u32 descriptor_version,
528 efi_memory_desc_t *virtual_map)
533 efi_sync_low_kernel_mappings();
534 local_irq_save(flags);
538 status = __efi_thunk(set_virtual_address_map, memory_map_size,
539 descriptor_size, descriptor_version, virtual_map);
542 local_irq_restore(flags);
547 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
549 return EFI_UNSUPPORTED;
552 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
554 return EFI_UNSUPPORTED;
558 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
561 return EFI_UNSUPPORTED;
565 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
567 return EFI_UNSUPPORTED;
570 static unsigned long efi_name_size(efi_char16_t *name)
572 return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
576 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
577 u32 *attr, unsigned long *data_size, void *data)
579 u8 buf[24] __aligned(8);
580 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
582 u32 phys_name, phys_vendor, phys_attr;
583 u32 phys_data_size, phys_data;
586 spin_lock_irqsave(&efi_runtime_lock, flags);
590 phys_data_size = virt_to_phys_or_null(data_size);
591 phys_vendor = virt_to_phys_or_null(vnd);
592 phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
593 phys_attr = virt_to_phys_or_null(attr);
594 phys_data = virt_to_phys_or_null_size(data, *data_size);
596 if (!phys_name || (data && !phys_data))
597 status = EFI_INVALID_PARAMETER;
599 status = efi_thunk(get_variable, phys_name, phys_vendor,
600 phys_attr, phys_data_size, phys_data);
602 spin_unlock_irqrestore(&efi_runtime_lock, flags);
608 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
609 u32 attr, unsigned long data_size, void *data)
611 u8 buf[24] __aligned(8);
612 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
613 u32 phys_name, phys_vendor, phys_data;
617 spin_lock_irqsave(&efi_runtime_lock, flags);
621 phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
622 phys_vendor = virt_to_phys_or_null(vnd);
623 phys_data = virt_to_phys_or_null_size(data, data_size);
625 if (!phys_name || (data && !phys_data))
626 status = EFI_INVALID_PARAMETER;
628 status = efi_thunk(set_variable, phys_name, phys_vendor,
629 attr, data_size, phys_data);
631 spin_unlock_irqrestore(&efi_runtime_lock, flags);
637 efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
638 u32 attr, unsigned long data_size,
641 u8 buf[24] __aligned(8);
642 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
643 u32 phys_name, phys_vendor, phys_data;
647 if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
648 return EFI_NOT_READY;
652 phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
653 phys_vendor = virt_to_phys_or_null(vnd);
654 phys_data = virt_to_phys_or_null_size(data, data_size);
656 if (!phys_name || (data && !phys_data))
657 status = EFI_INVALID_PARAMETER;
659 status = efi_thunk(set_variable, phys_name, phys_vendor,
660 attr, data_size, phys_data);
662 spin_unlock_irqrestore(&efi_runtime_lock, flags);
668 efi_thunk_get_next_variable(unsigned long *name_size,
672 u8 buf[24] __aligned(8);
673 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
675 u32 phys_name_size, phys_name, phys_vendor;
678 spin_lock_irqsave(&efi_runtime_lock, flags);
682 phys_name_size = virt_to_phys_or_null(name_size);
683 phys_vendor = virt_to_phys_or_null(vnd);
684 phys_name = virt_to_phys_or_null_size(name, *name_size);
687 status = EFI_INVALID_PARAMETER;
689 status = efi_thunk(get_next_variable, phys_name_size,
690 phys_name, phys_vendor);
692 spin_unlock_irqrestore(&efi_runtime_lock, flags);
699 efi_thunk_get_next_high_mono_count(u32 *count)
701 return EFI_UNSUPPORTED;
705 efi_thunk_reset_system(int reset_type, efi_status_t status,
706 unsigned long data_size, efi_char16_t *data)
711 spin_lock_irqsave(&efi_runtime_lock, flags);
713 phys_data = virt_to_phys_or_null_size(data, data_size);
715 efi_thunk(reset_system, reset_type, status, data_size, phys_data);
717 spin_unlock_irqrestore(&efi_runtime_lock, flags);
721 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
722 unsigned long count, unsigned long sg_list)
725 * To properly support this function we would need to repackage
726 * 'capsules' because the firmware doesn't understand 64-bit
729 return EFI_UNSUPPORTED;
733 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
734 u64 *remaining_space,
735 u64 *max_variable_size)
738 u32 phys_storage, phys_remaining, phys_max;
741 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
742 return EFI_UNSUPPORTED;
744 spin_lock_irqsave(&efi_runtime_lock, flags);
746 phys_storage = virt_to_phys_or_null(storage_space);
747 phys_remaining = virt_to_phys_or_null(remaining_space);
748 phys_max = virt_to_phys_or_null(max_variable_size);
750 status = efi_thunk(query_variable_info, attr, phys_storage,
751 phys_remaining, phys_max);
753 spin_unlock_irqrestore(&efi_runtime_lock, flags);
759 efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
760 u64 *remaining_space,
761 u64 *max_variable_size)
764 u32 phys_storage, phys_remaining, phys_max;
767 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
768 return EFI_UNSUPPORTED;
770 if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
771 return EFI_NOT_READY;
773 phys_storage = virt_to_phys_or_null(storage_space);
774 phys_remaining = virt_to_phys_or_null(remaining_space);
775 phys_max = virt_to_phys_or_null(max_variable_size);
777 status = efi_thunk(query_variable_info, attr, phys_storage,
778 phys_remaining, phys_max);
780 spin_unlock_irqrestore(&efi_runtime_lock, flags);
786 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
787 unsigned long count, u64 *max_size,
791 * To properly support this function we would need to repackage
792 * 'capsules' because the firmware doesn't understand 64-bit
795 return EFI_UNSUPPORTED;
798 void __init efi_thunk_runtime_setup(void)
800 if (!IS_ENABLED(CONFIG_EFI_MIXED))
803 efi.get_time = efi_thunk_get_time;
804 efi.set_time = efi_thunk_set_time;
805 efi.get_wakeup_time = efi_thunk_get_wakeup_time;
806 efi.set_wakeup_time = efi_thunk_set_wakeup_time;
807 efi.get_variable = efi_thunk_get_variable;
808 efi.get_next_variable = efi_thunk_get_next_variable;
809 efi.set_variable = efi_thunk_set_variable;
810 efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
811 efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
812 efi.reset_system = efi_thunk_reset_system;
813 efi.query_variable_info = efi_thunk_query_variable_info;
814 efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
815 efi.update_capsule = efi_thunk_update_capsule;
816 efi.query_capsule_caps = efi_thunk_query_capsule_caps;
819 efi_status_t __init __no_sanitize_address
820 efi_set_virtual_address_map(unsigned long memory_map_size,
821 unsigned long descriptor_size,
822 u32 descriptor_version,
823 efi_memory_desc_t *virtual_map,
824 unsigned long systab_phys)
826 const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
831 return efi_thunk_set_virtual_address_map(memory_map_size,
839 /* Disable interrupts around EFI calls: */
840 local_irq_save(flags);
841 status = efi_call(efi.runtime->set_virtual_address_map,
842 memory_map_size, descriptor_size,
843 descriptor_version, virtual_map);
844 local_irq_restore(flags);
848 /* grab the virtually remapped EFI runtime services table pointer */
849 efi.runtime = READ_ONCE(systab->runtime);