summaryrefslogtreecommitdiff
path: root/arch/x86/platform/efi/efi_64.c
blob: c5e393f8bb3f6363f47d94f42465155a2e333179 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
// SPDX-License-Identifier: GPL-2.0
/*
 * 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/memblock.h>
#include <linux/ioport.h>
#include <linux/mc146818rtc.h>
#include <linux/efi.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/ucs2_string.h>
#include <linux/mem_encrypt.h>
#include <linux/sched/task.h>

#include <asm/setup.h>
#include <asm/page.h>
#include <asm/e820/api.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>

/*
 * We allocate runtime services regions top-down, 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;

EXPORT_SYMBOL_GPL(efi_mm);

/*
 * 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().
 *
 * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
 * allocation.
 */
int __init efi_alloc_page_tables(void)
{
	pgd_t *pgd, *efi_pgd;
	p4d_t *p4d;
	pud_t *pud;
	gfp_t gfp_mask;

	if (efi_have_uv1_memmap())
		return 0;

	gfp_mask = GFP_KERNEL | __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);
	p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
	if (!p4d) {
		free_page((unsigned long)efi_pgd);
		return -ENOMEM;
	}

	pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
	if (!pud) {
		if (pgtable_l5_enabled())
			free_page((unsigned long) pgd_page_vaddr(*pgd));
		free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
		return -ENOMEM;
	}

	efi_mm.pgd = efi_pgd;
	mm_init_cpumask(&efi_mm);
	init_new_context(NULL, &efi_mm);

	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;
	p4d_t *p4d_k, *p4d_efi;
	pud_t *pud_k, *pud_efi;
	pgd_t *efi_pgd = efi_mm.pgd;

	if (efi_have_uv1_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.
	 */
	MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
	MAYBE_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);

	/*
	 * As with PGDs, we share all P4D entries apart from the one entry
	 * that covers the EFI runtime mapping space.
	 */
	BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));
	BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));

	pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
	pgd_k = pgd_offset_k(EFI_VA_END);
	p4d_efi = p4d_offset(pgd_efi, 0);
	p4d_k = p4d_offset(pgd_k, 0);

	num_entries = p4d_index(EFI_VA_END);
	memcpy(p4d_efi, p4d_k, sizeof(p4d_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);

	p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
	p4d_k = p4d_offset(pgd_k, EFI_VA_END);
	pud_efi = pud_offset(p4d_efi, 0);
	pud_k = pud_offset(p4d_k, 0);

	num_entries = pud_index(EFI_VA_END);
	memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);

	pud_efi = pud_offset(p4d_efi, EFI_VA_START);
	pud_k = pud_offset(p4d_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)
{
	phys_addr_t pa;

	if (!va)
		return 0;

	if (virt_addr_valid(va))
		return virt_to_phys(va);

	pa = slow_virt_to_phys(va);

	/* check if the object crosses a page boundary */
	if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
		return 0;

	return pa;
}

#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, pf, rodata;
	struct page *page;
	unsigned npages;
	pgd_t *pgd = efi_mm.pgd;

	if (efi_have_uv1_memmap())
		return 0;

	/*
	 * 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;
	pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
	if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
		pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
		return 1;
	}

	/*
	 * 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, pf)) {
		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 (!efi_is_mixed())
		return 0;

	page = alloc_page(GFP_KERNEL|__GFP_DMA32);
	if (!page) {
		pr_err("Unable to allocate EFI runtime stack < 4GB\n");
		return 1;
	}

	efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */

	npages = (_etext - _text) >> PAGE_SHIFT;
	text = __pa(_text);
	pfn = text >> PAGE_SHIFT;

	pf = _PAGE_ENC;
	if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
		pr_err("Failed to map kernel text 1:1\n");
		return 1;
	}

	npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
	rodata = __pa(__start_rodata);
	pfn = rodata >> PAGE_SHIFT;
	if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
		pr_err("Failed to map kernel rodata 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_mm.pgd;

	/*
	 * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
	 * executable images in memory that consist of both R-X and
	 * RW- sections, so we cannot apply read-only or non-exec
	 * permissions just yet. However, modern EFI systems provide
	 * a memory attributes table that describes those sections
	 * with the appropriate restricted permissions, which are
	 * applied in efi_runtime_update_mappings() below. All other
	 * regions can be mapped non-executable at this point, with
	 * the exception of boot services code regions, but those will
	 * be unmapped again entirely in efi_free_boot_services().
	 */
	if (md->type != EFI_BOOT_SERVICES_CODE &&
	    md->type != EFI_RUNTIME_SERVICES_CODE)
		flags |= _PAGE_NX;

	if (!(md->attribute & EFI_MEMORY_WB))
		flags |= _PAGE_PCD;

	if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
		flags |= _PAGE_ENC;

	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_have_uv1_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_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 __init parse_efi_setup(u64 phys_addr, u32 data_len)
{
	efi_setup = phys_addr + sizeof(struct setup_data);
}

static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
{
	unsigned long pfn;
	pgd_t *pgd = efi_mm.pgd;
	int err1, err2;

	/* Update the 1:1 mapping */
	pfn = md->phys_addr >> PAGE_SHIFT;
	err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
	if (err1) {
		pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
			   md->phys_addr, md->virt_addr);
	}

	err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
	if (err2) {
		pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
			   md->phys_addr, md->virt_addr);
	}

	return err1 || err2;
}

static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
{
	unsigned long pf = 0;

	if (md->attribute & EFI_MEMORY_XP)
		pf |= _PAGE_NX;

	if (!(md->attribute & EFI_MEMORY_RO))
		pf |= _PAGE_RW;

	if (sev_active())
		pf |= _PAGE_ENC;

	return efi_update_mappings(md, pf);
}

void __init efi_runtime_update_mappings(void)
{
	efi_memory_desc_t *md;

	if (efi_have_uv1_memmap()) {
		if (__supported_pte_mask & _PAGE_NX)
			runtime_code_page_mkexec();
		return;
	}

	/*
	 * Use the EFI Memory Attribute Table for mapping permissions if it
	 * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
	 */
	if (efi_enabled(EFI_MEM_ATTR)) {
		efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
		return;
	}

	/*
	 * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
	 * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
	 * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
	 * published by the firmware. Even if we find a buggy implementation of
	 * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
	 * EFI_PROPERTIES_TABLE, because of the same reason.
	 */

	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;

		if (sev_active())
			pf |= _PAGE_ENC;

		efi_update_mappings(md, pf);
	}
}

void __init efi_dump_pagetable(void)
{
#ifdef CONFIG_EFI_PGT_DUMP
	if (efi_have_uv1_memmap())
		ptdump_walk_pgd_level(NULL, &init_mm);
	else
		ptdump_walk_pgd_level(NULL, &efi_mm);
#endif
}

/*
 * Makes the calling thread switch to/from efi_mm context. Can be used
 * in a kernel thread and user context. Preemption needs to remain disabled
 * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
 * can not change under us.
 * It should be ensured that there are no concurent calls to this function.
 */
void efi_switch_mm(struct mm_struct *mm)
{
	efi_scratch.prev_mm = current->active_mm;
	current->active_mm = mm;
	switch_mm(efi_scratch.prev_mm, mm, NULL);
}

static DEFINE_SPINLOCK(efi_runtime_lock);

/*
 * DS and ES contain user values.  We need to save them.
 * The 32-bit EFI code needs a valid DS, ES, and SS.  There's no
 * need to save the old SS: __KERNEL_DS is always acceptable.
 */
#define __efi_thunk(func, ...)						\
({									\
	unsigned short __ds, __es;					\
	efi_status_t ____s;						\
									\
	savesegment(ds, __ds);						\
	savesegment(es, __es);						\
									\
	loadsegment(ss, __KERNEL_DS);					\
	loadsegment(ds, __KERNEL_DS);					\
	loadsegment(es, __KERNEL_DS);					\
									\
	____s = efi64_thunk(efi.runtime->mixed_mode.func, __VA_ARGS__);	\
									\
	loadsegment(ds, __ds);						\
	loadsegment(es, __es);						\
									\
	____s ^= (____s & BIT(31)) | (____s & BIT_ULL(31)) << 32;	\
	____s;								\
})

/*
 * 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.
 *
 * 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(func...)						\
({									\
	efi_status_t __s;						\
									\
	arch_efi_call_virt_setup();					\
									\
	__s = __efi_thunk(func);					\
									\
	arch_efi_call_virt_teardown();					\
									\
	__s;								\
})

static efi_status_t __init __no_sanitize_address
efi_thunk_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;

	efi_sync_low_kernel_mappings();
	local_irq_save(flags);

	efi_switch_mm(&efi_mm);

	status = __efi_thunk(set_virtual_address_map, memory_map_size,
			     descriptor_size, descriptor_version, virtual_map);

	efi_switch_mm(efi_scratch.prev_mm);
	local_irq_restore(flags);

	return status;
}

static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
	return EFI_UNSUPPORTED;
}

static efi_status_t efi_thunk_set_time(efi_time_t *tm)
{
	return EFI_UNSUPPORTED;
}

static efi_status_t
efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
			  efi_time_t *tm)
{
	return EFI_UNSUPPORTED;
}

static efi_status_t
efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
{
	return EFI_UNSUPPORTED;
}

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)
{
	u8 buf[24] __aligned(8);
	efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
	efi_status_t status;
	u32 phys_name, phys_vendor, phys_attr;
	u32 phys_data_size, phys_data;
	unsigned long flags;

	spin_lock_irqsave(&efi_runtime_lock, flags);

	*vnd = *vendor;

	phys_data_size = virt_to_phys_or_null(data_size);
	phys_vendor = virt_to_phys_or_null(vnd);
	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);

	if (!phys_name || (data && !phys_data))
		status = EFI_INVALID_PARAMETER;
	else
		status = efi_thunk(get_variable, phys_name, phys_vendor,
				   phys_attr, phys_data_size, phys_data);

	spin_unlock_irqrestore(&efi_runtime_lock, flags);

	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)
{
	u8 buf[24] __aligned(8);
	efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
	u32 phys_name, phys_vendor, phys_data;
	efi_status_t status;
	unsigned long flags;

	spin_lock_irqsave(&efi_runtime_lock, flags);

	*vnd = *vendor;

	phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
	phys_vendor = virt_to_phys_or_null(vnd);
	phys_data = virt_to_phys_or_null_size(data, data_size);

	if (!phys_name || (data && !phys_data))
		status = EFI_INVALID_PARAMETER;
	else
		status = efi_thunk(set_variable, phys_name, phys_vendor,
				   attr, data_size, phys_data);

	spin_unlock_irqrestore(&efi_runtime_lock, flags);

	return status;
}

static efi_status_t
efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
				   u32 attr, unsigned long data_size,
				   void *data)
{
	u8 buf[24] __aligned(8);
	efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
	u32 phys_name, phys_vendor, phys_data;
	efi_status_t status;
	unsigned long flags;

	if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
		return EFI_NOT_READY;

	*vnd = *vendor;

	phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
	phys_vendor = virt_to_phys_or_null(vnd);
	phys_data = virt_to_phys_or_null_size(data, data_size);

	if (!phys_name || (data && !phys_data))
		status = EFI_INVALID_PARAMETER;
	else
		status = efi_thunk(set_variable, phys_name, phys_vendor,
				   attr, data_size, phys_data);

	spin_unlock_irqrestore(&efi_runtime_lock, flags);

	return status;
}

static efi_status_t
efi_thunk_get_next_variable(unsigned long *name_size,
			    efi_char16_t *name,
			    efi_guid_t *vendor)
{
	u8 buf[24] __aligned(8);
	efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
	efi_status_t status;
	u32 phys_name_size, phys_name, phys_vendor;
	unsigned long flags;

	spin_lock_irqsave(&efi_runtime_lock, flags);

	*vnd = *vendor;

	phys_name_size = virt_to_phys_or_null(name_size);
	phys_vendor = virt_to_phys_or_null(vnd);
	phys_name = virt_to_phys_or_null_size(name, *name_size);

	if (!phys_name)
		status = EFI_INVALID_PARAMETER;
	else
		status = efi_thunk(get_next_variable, phys_name_size,
				   phys_name, phys_vendor);

	spin_unlock_irqrestore(&efi_runtime_lock, flags);

	*vendor = *vnd;
	return status;
}

static efi_status_t
efi_thunk_get_next_high_mono_count(u32 *count)
{
	return EFI_UNSUPPORTED;
}

static void
efi_thunk_reset_system(int reset_type, efi_status_t status,
		       unsigned long data_size, efi_char16_t *data)
{
	u32 phys_data;
	unsigned long flags;

	spin_lock_irqsave(&efi_runtime_lock, flags);

	phys_data = virt_to_phys_or_null_size(data, data_size);

	efi_thunk(reset_system, reset_type, status, data_size, phys_data);

	spin_unlock_irqrestore(&efi_runtime_lock, flags);
}

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;
	unsigned long flags;

	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
		return EFI_UNSUPPORTED;

	spin_lock_irqsave(&efi_runtime_lock, flags);

	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);

	spin_unlock_irqrestore(&efi_runtime_lock, flags);

	return status;
}

static efi_status_t
efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
					  u64 *remaining_space,
					  u64 *max_variable_size)
{
	efi_status_t status;
	u32 phys_storage, phys_remaining, phys_max;
	unsigned long flags;

	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
		return EFI_UNSUPPORTED;

	if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
		return EFI_NOT_READY;

	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);

	spin_unlock_irqrestore(&efi_runtime_lock, flags);

	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 __init efi_thunk_runtime_setup(void)
{
	if (!IS_ENABLED(CONFIG_EFI_MIXED))
		return;

	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.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
	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.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
	efi.update_capsule = efi_thunk_update_capsule;
	efi.query_capsule_caps = efi_thunk_query_capsule_caps;
}

efi_status_t __init __no_sanitize_address
efi_set_virtual_address_map(unsigned long memory_map_size,
			    unsigned long descriptor_size,
			    u32 descriptor_version,
			    efi_memory_desc_t *virtual_map,
			    unsigned long systab_phys)
{
	const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
	efi_status_t status;
	unsigned long flags;
	pgd_t *save_pgd = NULL;

	if (efi_is_mixed())
		return efi_thunk_set_virtual_address_map(memory_map_size,
							 descriptor_size,
							 descriptor_version,
							 virtual_map);

	if (efi_have_uv1_memmap()) {
		save_pgd = efi_uv1_memmap_phys_prolog();
		if (!save_pgd)
			return EFI_ABORTED;
	} else {
		efi_switch_mm(&efi_mm);
	}

	kernel_fpu_begin();

	/* Disable interrupts around EFI calls: */
	local_irq_save(flags);
	status = efi_call(efi.runtime->set_virtual_address_map,
			  memory_map_size, descriptor_size,
			  descriptor_version, virtual_map);
	local_irq_restore(flags);

	kernel_fpu_end();

	/* grab the virtually remapped EFI runtime services table pointer */
	efi.runtime = READ_ONCE(systab->runtime);

	if (save_pgd)
		efi_uv1_memmap_phys_epilog(save_pgd);
	else
		efi_switch_mm(efi_scratch.prev_mm);

	return status;
}