aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/platform/efi/efi.c
blob: 37718f0f053d53346566c80958885f159b61dcde (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
/*
 * 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.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/efi.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
#define PFX 		"EFI: "

int efi_enabled;
EXPORT_SYMBOL(efi_enabled);

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 int __init setup_noefi(char *arg)
{
	efi_enabled = 0;
	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, vendor, attr,
			      data_size, data);
}

static efi_status_t virt_efi_query_variable_info(u32 attr,
						 u64 *storage_space,
						 u64 *remaining_space,
						 u64 *max_variable_size)
{
	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
		return EFI_UNSUPPORTED;

	return efi_call_virt4(query_variable_info, attr, storage_space,
			      remaining_space, max_variable_size);
}

static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
{
	return efi_call_virt1(get_next_high_mono_count, count);
}

static void virt_efi_reset_system(int reset_type,
				  efi_status_t status,
				  unsigned long data_size,
				  efi_char16_t *data)
{
	efi_call_virt4(reset_system, reset_type, status,
		       data_size, data);
}

static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
					    unsigned long count,
					    unsigned long sg_list)
{
	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
		return EFI_UNSUPPORTED;

	return efi_call_virt3(update_capsule, capsules, count, sg_list);
}

static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
						unsigned long count,
						u64 *max_size,
						int *reset_type)
{
	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
		return EFI_UNSUPPORTED;

	return efi_call_virt4(query_capsule_caps, capsules, count, max_size,
			      reset_type);
}

static efi_status_t __init phys_efi_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;

	efi_call_phys_prelog();
	status = efi_call_phys4(efi_phys.set_virtual_address_map,
				memory_map_size, descriptor_size,
				descriptor_version, virtual_map);
	efi_call_phys_epilog();
	return status;
}

static efi_status_t __init phys_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);
	efi_call_phys_prelog();
	status = efi_call_phys2(efi_phys.get_time, tm, tc);
	efi_call_phys_epilog();
	spin_unlock_irqrestore(&rtc_lock, flags);
	return status;
}

int efi_set_rtc_mmss(unsigned long nowtime)
{
	int real_seconds, real_minutes;
	efi_status_t 	status;
	efi_time_t 	eft;
	efi_time_cap_t 	cap;

	status = efi.get_time(&eft, &cap);
	if (status != EFI_SUCCESS) {
		printk(KERN_ERR "Oops: efitime: can't read time!\n");
		return -1;
	}

	real_seconds = nowtime % 60;
	real_minutes = nowtime / 60;
	if (((abs(real_minutes - eft.minute) + 15)/30) & 1)
		real_minutes += 30;
	real_minutes %= 60;
	eft.minute = real_minutes;
	eft.second = real_seconds;

	status = efi.set_time(&eft);
	if (status != EFI_SUCCESS) {
		printk(KERN_ERR "Oops: efitime: can't write time!\n");
		return -1;
	}
	return 0;
}

unsigned long efi_get_time(void)
{
	efi_status_t status;
	efi_time_t eft;
	efi_time_cap_t cap;

	status = efi.get_time(&eft, &cap);
	if (status != EFI_SUCCESS)
		printk(KERN_ERR "Oops: efitime: can't read time!\n");

	return mktime(eft.year, eft.month, eft.day, eft.hour,
		      eft.minute, eft.second);
}

/*
 * Tell the kernel about the EFI memory map.  This might include
 * more than the max 128 entries that can fit in the e820 legacy
 * (zeropage) memory map.
 */

static void __init do_add_efi_memmap(void)
{
	void *p;

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		efi_memory_desc_t *md = p;
		unsigned long long start = md->phys_addr;
		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
		int e820_type;

		switch (md->type) {
		case EFI_LOADER_CODE:
		case EFI_LOADER_DATA:
		case EFI_BOOT_SERVICES_CODE:
		case EFI_BOOT_SERVICES_DATA:
		case EFI_CONVENTIONAL_MEMORY:
			if (md->attribute & EFI_MEMORY_WB)
				e820_type = E820_RAM;
			else
				e820_type = E820_RESERVED;
			break;
		case EFI_ACPI_RECLAIM_MEMORY:
			e820_type = E820_ACPI;
			break;
		case EFI_ACPI_MEMORY_NVS:
			e820_type = E820_NVS;
			break;
		case EFI_UNUSABLE_MEMORY:
			e820_type = E820_UNUSABLE;
			break;
		default:
			/*
			 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
			 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
			 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
			 */
			e820_type = E820_RESERVED;
			break;
		}
		e820_add_region(start, size, e820_type);
	}
	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
}

void __init efi_memblock_x86_reserve_range(void)
{
	unsigned long pmap;

#ifdef CONFIG_X86_32
	pmap = boot_params.efi_info.efi_memmap;
#else
	pmap = (boot_params.efi_info.efi_memmap |
		((__u64)boot_params.efi_info.efi_memmap_hi<<32));
#endif
	memmap.phys_map = (void *)pmap;
	memmap.nr_map = boot_params.efi_info.efi_memmap_size /
		boot_params.efi_info.efi_memdesc_size;
	memmap.desc_version = boot_params.efi_info.efi_memdesc_version;
	memmap.desc_size = boot_params.efi_info.efi_memdesc_size;
	memblock_x86_reserve_range(pmap, pmap + memmap.nr_map * memmap.desc_size,
		      "EFI memmap");
}

#if EFI_DEBUG
static void __init print_efi_memmap(void)
{
	efi_memory_desc_t *md;
	void *p;
	int i;

	for (p = memmap.map, i = 0;
	     p < memmap.map_end;
	     p += memmap.desc_size, i++) {
		md = p;
		printk(KERN_INFO PFX "mem%02u: type=%u, attr=0x%llx, "
			"range=[0x%016llx-0x%016llx) (%lluMB)\n",
			i, md->type, md->attribute, md->phys_addr,
			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
	}
}
#endif  /*  EFI_DEBUG  */

void __init efi_reserve_boot_services(void)
{
	void *p;

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		efi_memory_desc_t *md = p;
		u64 start = md->phys_addr;
		u64 size = md->num_pages << EFI_PAGE_SHIFT;

		if (md->type != EFI_BOOT_SERVICES_CODE &&
		    md->type != EFI_BOOT_SERVICES_DATA)
			continue;
		/* Only reserve where possible:
		 * - Not within any already allocated areas
		 * - Not over any memory area (really needed, if above?)
		 * - Not within any part of the kernel
		 * - Not the bios reserved area
		*/
		if ((start+size >= virt_to_phys(_text)
				&& start <= virt_to_phys(_end)) ||
			!e820_all_mapped(start, start+size, E820_RAM) ||
			memblock_x86_check_reserved_size(&start, &size,
							1<<EFI_PAGE_SHIFT)) {
			/* Could not reserve, skip it */
			md->num_pages = 0;
			memblock_dbg(PFX "Could not reserve boot range "
					"[0x%010llx-0x%010llx]\n",
						start, start+size-1);
		} else
			memblock_x86_reserve_range(start, start+size,
							"EFI Boot");
	}
}

static void __init efi_free_boot_services(void)
{
	void *p;

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		efi_memory_desc_t *md = p;
		unsigned long long start = md->phys_addr;
		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;

		if (md->type != EFI_BOOT_SERVICES_CODE &&
		    md->type != EFI_BOOT_SERVICES_DATA)
			continue;

		/* Could not reserve boot area */
		if (!size)
			continue;

		free_bootmem_late(start, size);
	}
}

void __init efi_init(void)
{
	efi_config_table_t *config_tables;
	efi_runtime_services_t *runtime;
	efi_char16_t *c16;
	char vendor[100] = "unknown";
	int i = 0;
	void *tmp;

#ifdef CONFIG_X86_32
	efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
#else
	efi_phys.systab = (efi_system_table_t *)
		(boot_params.efi_info.efi_systab |
		 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
#endif

	efi.systab = early_ioremap((unsigned long)efi_phys.systab,
				   sizeof(efi_system_table_t));
	if (efi.systab == NULL)
		printk(KERN_ERR "Couldn't map the EFI system table!\n");
	memcpy(&efi_systab, efi.systab, sizeof(efi_system_table_t));
	early_iounmap(efi.systab, sizeof(efi_system_table_t));
	efi.systab = &efi_systab;

	/*
	 * Verify the EFI Table
	 */
	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
		printk(KERN_ERR "EFI system table signature incorrect!\n");
	if ((efi.systab->hdr.revision >> 16) == 0)
		printk(KERN_ERR "Warning: EFI system table version "
		       "%d.%02d, expected 1.00 or greater!\n",
		       efi.systab->hdr.revision >> 16,
		       efi.systab->hdr.revision & 0xffff);

	/*
	 * Show what we know for posterity
	 */
	c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
	if (c16) {
		for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
			vendor[i] = *c16++;
		vendor[i] = '\0';
	} else
		printk(KERN_ERR PFX "Could not map the firmware vendor!\n");
	early_iounmap(tmp, 2);

	printk(KERN_INFO "EFI v%u.%.02u by %s\n",
	       efi.systab->hdr.revision >> 16,
	       efi.systab->hdr.revision & 0xffff, vendor);

	/*
	 * Let's see what config tables the firmware passed to us.
	 */
	config_tables = early_ioremap(
		efi.systab->tables,
		efi.systab->nr_tables * sizeof(efi_config_table_t));
	if (config_tables == NULL)
		printk(KERN_ERR "Could not map EFI Configuration Table!\n");

	printk(KERN_INFO);
	for (i = 0; i < efi.systab->nr_tables; i++) {
		if (!efi_guidcmp(config_tables[i].guid, MPS_TABLE_GUID)) {
			efi.mps = config_tables[i].table;
			printk(" MPS=0x%lx ", config_tables[i].table);
		} else if (!efi_guidcmp(config_tables[i].guid,
					ACPI_20_TABLE_GUID)) {
			efi.acpi20 = config_tables[i].table;
			printk(" ACPI 2.0=0x%lx ", config_tables[i].table);
		} else if (!efi_guidcmp(config_tables[i].guid,
					ACPI_TABLE_GUID)) {
			efi.acpi = config_tables[i].table;
			printk(" ACPI=0x%lx ", config_tables[i].table);
		} else if (!efi_guidcmp(config_tables[i].guid,
					SMBIOS_TABLE_GUID)) {
			efi.smbios = config_tables[i].table;
			printk(" SMBIOS=0x%lx ", config_tables[i].table);
#ifdef CONFIG_X86_UV
		} else if (!efi_guidcmp(config_tables[i].guid,
					UV_SYSTEM_TABLE_GUID)) {
			efi.uv_systab = config_tables[i].table;
			printk(" UVsystab=0x%lx ", config_tables[i].table);
#endif
		} else if (!efi_guidcmp(config_tables[i].guid,
					HCDP_TABLE_GUID)) {
			efi.hcdp = config_tables[i].table;
			printk(" HCDP=0x%lx ", config_tables[i].table);
		} else if (!efi_guidcmp(config_tables[i].guid,
					UGA_IO_PROTOCOL_GUID)) {
			efi.uga = config_tables[i].table;
			printk(" UGA=0x%lx ", config_tables[i].table);
		}
	}
	printk("\n");
	early_iounmap(config_tables,
			  efi.systab->nr_tables * sizeof(efi_config_table_t));

	/*
	 * Check out the runtime services table. We need to map
	 * the runtime services table so that we can grab the physical
	 * address of several of the EFI runtime functions, needed to
	 * set the firmware into virtual mode.
	 */
	runtime = early_ioremap((unsigned long)efi.systab->runtime,
				sizeof(efi_runtime_services_t));
	if (runtime != NULL) {
		/*
		 * We will only need *early* access to the following
		 * two EFI runtime services before set_virtual_address_map
		 * is invoked.
		 */
		efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
		efi_phys.set_virtual_address_map =
			(efi_set_virtual_address_map_t *)
			runtime->set_virtual_address_map;
		/*
		 * Make efi_get_time can be called before entering
		 * virtual mode.
		 */
		efi.get_time = phys_efi_get_time;
	} else
		printk(KERN_ERR "Could not map the EFI runtime service "
		       "table!\n");
	early_iounmap(runtime, sizeof(efi_runtime_services_t));

	/* Map the EFI memory map */
	memmap.map = early_ioremap((unsigned long)memmap.phys_map,
				   memmap.nr_map * memmap.desc_size);
	if (memmap.map == NULL)
		printk(KERN_ERR "Could not map the EFI memory map!\n");
	memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);

	if (memmap.desc_size != sizeof(efi_memory_desc_t))
		printk(KERN_WARNING
		  "Kernel-defined memdesc doesn't match the one from EFI!\n");

	if (add_efi_memmap)
		do_add_efi_memmap();

#ifdef CONFIG_X86_32
	x86_platform.get_wallclock = efi_get_time;
	x86_platform.set_wallclock = efi_set_rtc_mmss;
#endif

#if EFI_DEBUG
	print_efi_memmap();
#endif
}

void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
{
	u64 addr, npages;

	addr = md->virt_addr;
	npages = md->num_pages;

	memrange_efi_to_native(&addr, &npages);

	if (executable)
		set_memory_x(addr, npages);
	else
		set_memory_nx(addr, npages);
}

static void __init runtime_code_page_mkexec(void)
{
	efi_memory_desc_t *md;
	void *p;

	/* Make EFI runtime service code area executable */
	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		md = p;

		if (md->type != EFI_RUNTIME_SERVICES_CODE)
			continue;

		efi_set_executable(md, true);
	}
}

/*
 * This function will switch the EFI runtime services to virtual mode.
 * Essentially, look through the EFI memmap and map every region that
 * has the runtime attribute bit set in its memory descriptor and update
 * that memory descriptor with the virtual address obtained from ioremap().
 * This enables the runtime services to be called without having to
 * thunk back into physical mode for every invocation.
 */
void __init efi_enter_virtual_mode(void)
{
	efi_memory_desc_t *md, *prev_md = NULL;
	efi_status_t status;
	unsigned long size;
	u64 end, systab, addr, npages, end_pfn;
	void *p, *va, *new_memmap = NULL;
	int count = 0;

	efi.systab = NULL;

	/* Merge contiguous regions of the same type and attribute */
	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		u64 prev_size;
		md = p;

		if (!prev_md) {
			prev_md = md;
			continue;
		}

		if (prev_md->type != md->type ||
		    prev_md->attribute != md->attribute) {
			prev_md = md;
			continue;
		}

		prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;

		if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
			prev_md->num_pages += md->num_pages;
			md->type = EFI_RESERVED_TYPE;
			md->attribute = 0;
			continue;
		}
		prev_md = md;
	}

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		md = p;
		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
		    md->type != EFI_BOOT_SERVICES_CODE &&
		    md->type != EFI_BOOT_SERVICES_DATA)
			continue;

		size = md->num_pages << EFI_PAGE_SHIFT;
		end = md->phys_addr + size;

		end_pfn = PFN_UP(end);
		if (end_pfn <= max_low_pfn_mapped
		    || (end_pfn > (1UL << (32 - PAGE_SHIFT))
			&& end_pfn <= max_pfn_mapped))
			va = __va(md->phys_addr);
		else
			va = efi_ioremap(md->phys_addr, size, md->type);

		md->virt_addr = (u64) (unsigned long) va;

		if (!va) {
			printk(KERN_ERR PFX "ioremap of 0x%llX failed!\n",
			       (unsigned long long)md->phys_addr);
			continue;
		}

		if (!(md->attribute & EFI_MEMORY_WB)) {
			addr = md->virt_addr;
			npages = md->num_pages;
			memrange_efi_to_native(&addr, &npages);
			set_memory_uc(addr, npages);
		}

		systab = (u64) (unsigned long) efi_phys.systab;
		if (md->phys_addr <= systab && systab < end) {
			systab += md->virt_addr - md->phys_addr;
			efi.systab = (efi_system_table_t *) (unsigned long) systab;
		}
		new_memmap = krealloc(new_memmap,
				      (count + 1) * memmap.desc_size,
				      GFP_KERNEL);
		memcpy(new_memmap + (count * memmap.desc_size), md,
		       memmap.desc_size);
		count++;
	}

	BUG_ON(!efi.systab);

	status = phys_efi_set_virtual_address_map(
		memmap.desc_size * count,
		memmap.desc_size,
		memmap.desc_version,
		(efi_memory_desc_t *)__pa(new_memmap));

	if (status != EFI_SUCCESS) {
		printk(KERN_ALERT "Unable to switch EFI into virtual mode "
		       "(status=%lx)!\n", status);
		panic("EFI call to SetVirtualAddressMap() failed!");
	}

	/*
	 * Thankfully, it does seem that no runtime services other than
	 * SetVirtualAddressMap() will touch boot services code, so we can
	 * get rid of it all at this point
	 */
	efi_free_boot_services();

	/*
	 * Now that EFI is in virtual mode, update the function
	 * pointers in the runtime service table to the new virtual addresses.
	 *
	 * Call EFI services through wrapper functions.
	 */
	efi.get_time = virt_efi_get_time;
	efi.set_time = virt_efi_set_time;
	efi.get_wakeup_time = virt_efi_get_wakeup_time;
	efi.set_wakeup_time = virt_efi_set_wakeup_time;
	efi.get_variable = virt_efi_get_variable;
	efi.get_next_variable = virt_efi_get_next_variable;
	efi.set_variable = virt_efi_set_variable;
	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
	efi.reset_system = virt_efi_reset_system;
	efi.set_virtual_address_map = NULL;
	efi.query_variable_info = virt_efi_query_variable_info;
	efi.update_capsule = virt_efi_update_capsule;
	efi.query_capsule_caps = virt_efi_query_capsule_caps;
	if (__supported_pte_mask & _PAGE_NX)
		runtime_code_page_mkexec();
	early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
	memmap.map = NULL;
	kfree(new_memmap);
}

/*
 * Convenience functions to obtain memory types and attributes
 */
u32 efi_mem_type(unsigned long phys_addr)
{
	efi_memory_desc_t *md;
	void *p;

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		md = p;
		if ((md->phys_addr <= phys_addr) &&
		    (phys_addr < (md->phys_addr +
				  (md->num_pages << EFI_PAGE_SHIFT))))
			return md->type;
	}
	return 0;
}

u64 efi_mem_attributes(unsigned long phys_addr)
{
	efi_memory_desc_t *md;
	void *p;

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		md = p;
		if ((md->phys_addr <= phys_addr) &&
		    (phys_addr < (md->phys_addr +
				  (md->num_pages << EFI_PAGE_SHIFT))))
			return md->attribute;
	}
	return 0;
}