xref: /linux/arch/x86/platform/efi/efi.c (revision 7056741fd9fc14a65608549a4657cf5178f05f63)
1 /*
2  * Common EFI (Extensible Firmware Interface) support functions
3  * Based on Extensible Firmware Interface Specification version 1.0
4  *
5  * Copyright (C) 1999 VA Linux Systems
6  * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
7  * Copyright (C) 1999-2002 Hewlett-Packard Co.
8  *	David Mosberger-Tang <davidm@hpl.hp.com>
9  *	Stephane Eranian <eranian@hpl.hp.com>
10  * Copyright (C) 2005-2008 Intel Co.
11  *	Fenghua Yu <fenghua.yu@intel.com>
12  *	Bibo Mao <bibo.mao@intel.com>
13  *	Chandramouli Narayanan <mouli@linux.intel.com>
14  *	Huang Ying <ying.huang@intel.com>
15  *
16  * Copied from efi_32.c to eliminate the duplicated code between EFI
17  * 32/64 support code. --ying 2007-10-26
18  *
19  * All EFI Runtime Services are not implemented yet as EFI only
20  * supports physical mode addressing on SoftSDV. This is to be fixed
21  * in a future version.  --drummond 1999-07-20
22  *
23  * Implemented EFI runtime services and virtual mode calls.  --davidm
24  *
25  * Goutham Rao: <goutham.rao@intel.com>
26  *	Skip non-WB memory and ignore empty memory ranges.
27  */
28 
29 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30 
31 #include <linux/kernel.h>
32 #include <linux/init.h>
33 #include <linux/efi.h>
34 #include <linux/efi-bgrt.h>
35 #include <linux/export.h>
36 #include <linux/bootmem.h>
37 #include <linux/memblock.h>
38 #include <linux/spinlock.h>
39 #include <linux/uaccess.h>
40 #include <linux/time.h>
41 #include <linux/io.h>
42 #include <linux/reboot.h>
43 #include <linux/bcd.h>
44 
45 #include <asm/setup.h>
46 #include <asm/efi.h>
47 #include <asm/time.h>
48 #include <asm/cacheflush.h>
49 #include <asm/tlbflush.h>
50 #include <asm/x86_init.h>
51 
52 #define EFI_DEBUG	1
53 
54 int efi_enabled;
55 EXPORT_SYMBOL(efi_enabled);
56 
57 struct efi __read_mostly efi = {
58 	.mps        = EFI_INVALID_TABLE_ADDR,
59 	.acpi       = EFI_INVALID_TABLE_ADDR,
60 	.acpi20     = EFI_INVALID_TABLE_ADDR,
61 	.smbios     = EFI_INVALID_TABLE_ADDR,
62 	.sal_systab = EFI_INVALID_TABLE_ADDR,
63 	.boot_info  = EFI_INVALID_TABLE_ADDR,
64 	.hcdp       = EFI_INVALID_TABLE_ADDR,
65 	.uga        = EFI_INVALID_TABLE_ADDR,
66 	.uv_systab  = EFI_INVALID_TABLE_ADDR,
67 };
68 EXPORT_SYMBOL(efi);
69 
70 struct efi_memory_map memmap;
71 
72 bool efi_64bit;
73 static bool efi_native;
74 
75 static struct efi efi_phys __initdata;
76 static efi_system_table_t efi_systab __initdata;
77 
78 static int __init setup_noefi(char *arg)
79 {
80 	efi_enabled = 0;
81 	return 0;
82 }
83 early_param("noefi", setup_noefi);
84 
85 int add_efi_memmap;
86 EXPORT_SYMBOL(add_efi_memmap);
87 
88 static int __init setup_add_efi_memmap(char *arg)
89 {
90 	add_efi_memmap = 1;
91 	return 0;
92 }
93 early_param("add_efi_memmap", setup_add_efi_memmap);
94 
95 
96 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
97 {
98 	unsigned long flags;
99 	efi_status_t status;
100 
101 	spin_lock_irqsave(&rtc_lock, flags);
102 	status = efi_call_virt2(get_time, tm, tc);
103 	spin_unlock_irqrestore(&rtc_lock, flags);
104 	return status;
105 }
106 
107 static efi_status_t virt_efi_set_time(efi_time_t *tm)
108 {
109 	unsigned long flags;
110 	efi_status_t status;
111 
112 	spin_lock_irqsave(&rtc_lock, flags);
113 	status = efi_call_virt1(set_time, tm);
114 	spin_unlock_irqrestore(&rtc_lock, flags);
115 	return status;
116 }
117 
118 static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
119 					     efi_bool_t *pending,
120 					     efi_time_t *tm)
121 {
122 	unsigned long flags;
123 	efi_status_t status;
124 
125 	spin_lock_irqsave(&rtc_lock, flags);
126 	status = efi_call_virt3(get_wakeup_time,
127 				enabled, pending, tm);
128 	spin_unlock_irqrestore(&rtc_lock, flags);
129 	return status;
130 }
131 
132 static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
133 {
134 	unsigned long flags;
135 	efi_status_t status;
136 
137 	spin_lock_irqsave(&rtc_lock, flags);
138 	status = efi_call_virt2(set_wakeup_time,
139 				enabled, tm);
140 	spin_unlock_irqrestore(&rtc_lock, flags);
141 	return status;
142 }
143 
144 static efi_status_t virt_efi_get_variable(efi_char16_t *name,
145 					  efi_guid_t *vendor,
146 					  u32 *attr,
147 					  unsigned long *data_size,
148 					  void *data)
149 {
150 	return efi_call_virt5(get_variable,
151 			      name, vendor, attr,
152 			      data_size, data);
153 }
154 
155 static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
156 					       efi_char16_t *name,
157 					       efi_guid_t *vendor)
158 {
159 	return efi_call_virt3(get_next_variable,
160 			      name_size, name, vendor);
161 }
162 
163 static efi_status_t virt_efi_set_variable(efi_char16_t *name,
164 					  efi_guid_t *vendor,
165 					  u32 attr,
166 					  unsigned long data_size,
167 					  void *data)
168 {
169 	return efi_call_virt5(set_variable,
170 			      name, vendor, attr,
171 			      data_size, data);
172 }
173 
174 static efi_status_t virt_efi_query_variable_info(u32 attr,
175 						 u64 *storage_space,
176 						 u64 *remaining_space,
177 						 u64 *max_variable_size)
178 {
179 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
180 		return EFI_UNSUPPORTED;
181 
182 	return efi_call_virt4(query_variable_info, attr, storage_space,
183 			      remaining_space, max_variable_size);
184 }
185 
186 static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
187 {
188 	return efi_call_virt1(get_next_high_mono_count, count);
189 }
190 
191 static void virt_efi_reset_system(int reset_type,
192 				  efi_status_t status,
193 				  unsigned long data_size,
194 				  efi_char16_t *data)
195 {
196 	efi_call_virt4(reset_system, reset_type, status,
197 		       data_size, data);
198 }
199 
200 static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
201 					    unsigned long count,
202 					    unsigned long sg_list)
203 {
204 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
205 		return EFI_UNSUPPORTED;
206 
207 	return efi_call_virt3(update_capsule, capsules, count, sg_list);
208 }
209 
210 static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
211 						unsigned long count,
212 						u64 *max_size,
213 						int *reset_type)
214 {
215 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
216 		return EFI_UNSUPPORTED;
217 
218 	return efi_call_virt4(query_capsule_caps, capsules, count, max_size,
219 			      reset_type);
220 }
221 
222 static efi_status_t __init phys_efi_set_virtual_address_map(
223 	unsigned long memory_map_size,
224 	unsigned long descriptor_size,
225 	u32 descriptor_version,
226 	efi_memory_desc_t *virtual_map)
227 {
228 	efi_status_t status;
229 
230 	efi_call_phys_prelog();
231 	status = efi_call_phys4(efi_phys.set_virtual_address_map,
232 				memory_map_size, descriptor_size,
233 				descriptor_version, virtual_map);
234 	efi_call_phys_epilog();
235 	return status;
236 }
237 
238 static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
239 					     efi_time_cap_t *tc)
240 {
241 	unsigned long flags;
242 	efi_status_t status;
243 
244 	spin_lock_irqsave(&rtc_lock, flags);
245 	efi_call_phys_prelog();
246 	status = efi_call_phys2(efi_phys.get_time, virt_to_phys(tm),
247 				virt_to_phys(tc));
248 	efi_call_phys_epilog();
249 	spin_unlock_irqrestore(&rtc_lock, flags);
250 	return status;
251 }
252 
253 int efi_set_rtc_mmss(unsigned long nowtime)
254 {
255 	int real_seconds, real_minutes;
256 	efi_status_t 	status;
257 	efi_time_t 	eft;
258 	efi_time_cap_t 	cap;
259 
260 	status = efi.get_time(&eft, &cap);
261 	if (status != EFI_SUCCESS) {
262 		pr_err("Oops: efitime: can't read time!\n");
263 		return -1;
264 	}
265 
266 	real_seconds = nowtime % 60;
267 	real_minutes = nowtime / 60;
268 	if (((abs(real_minutes - eft.minute) + 15)/30) & 1)
269 		real_minutes += 30;
270 	real_minutes %= 60;
271 	eft.minute = real_minutes;
272 	eft.second = real_seconds;
273 
274 	status = efi.set_time(&eft);
275 	if (status != EFI_SUCCESS) {
276 		pr_err("Oops: efitime: can't write time!\n");
277 		return -1;
278 	}
279 	return 0;
280 }
281 
282 unsigned long efi_get_time(void)
283 {
284 	efi_status_t status;
285 	efi_time_t eft;
286 	efi_time_cap_t cap;
287 
288 	status = efi.get_time(&eft, &cap);
289 	if (status != EFI_SUCCESS)
290 		pr_err("Oops: efitime: can't read time!\n");
291 
292 	return mktime(eft.year, eft.month, eft.day, eft.hour,
293 		      eft.minute, eft.second);
294 }
295 
296 /*
297  * Tell the kernel about the EFI memory map.  This might include
298  * more than the max 128 entries that can fit in the e820 legacy
299  * (zeropage) memory map.
300  */
301 
302 static void __init do_add_efi_memmap(void)
303 {
304 	void *p;
305 
306 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
307 		efi_memory_desc_t *md = p;
308 		unsigned long long start = md->phys_addr;
309 		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
310 		int e820_type;
311 
312 		switch (md->type) {
313 		case EFI_LOADER_CODE:
314 		case EFI_LOADER_DATA:
315 		case EFI_BOOT_SERVICES_CODE:
316 		case EFI_BOOT_SERVICES_DATA:
317 		case EFI_CONVENTIONAL_MEMORY:
318 			if (md->attribute & EFI_MEMORY_WB)
319 				e820_type = E820_RAM;
320 			else
321 				e820_type = E820_RESERVED;
322 			break;
323 		case EFI_ACPI_RECLAIM_MEMORY:
324 			e820_type = E820_ACPI;
325 			break;
326 		case EFI_ACPI_MEMORY_NVS:
327 			e820_type = E820_NVS;
328 			break;
329 		case EFI_UNUSABLE_MEMORY:
330 			e820_type = E820_UNUSABLE;
331 			break;
332 		default:
333 			/*
334 			 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
335 			 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
336 			 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
337 			 */
338 			e820_type = E820_RESERVED;
339 			break;
340 		}
341 		e820_add_region(start, size, e820_type);
342 	}
343 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
344 }
345 
346 int __init efi_memblock_x86_reserve_range(void)
347 {
348 	unsigned long pmap;
349 
350 #ifdef CONFIG_X86_32
351 	/* Can't handle data above 4GB at this time */
352 	if (boot_params.efi_info.efi_memmap_hi) {
353 		pr_err("Memory map is above 4GB, disabling EFI.\n");
354 		return -EINVAL;
355 	}
356 	pmap = boot_params.efi_info.efi_memmap;
357 #else
358 	pmap = (boot_params.efi_info.efi_memmap |
359 		((__u64)boot_params.efi_info.efi_memmap_hi<<32));
360 #endif
361 	memmap.phys_map = (void *)pmap;
362 	memmap.nr_map = boot_params.efi_info.efi_memmap_size /
363 		boot_params.efi_info.efi_memdesc_size;
364 	memmap.desc_version = boot_params.efi_info.efi_memdesc_version;
365 	memmap.desc_size = boot_params.efi_info.efi_memdesc_size;
366 	memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
367 
368 	return 0;
369 }
370 
371 #if EFI_DEBUG
372 static void __init print_efi_memmap(void)
373 {
374 	efi_memory_desc_t *md;
375 	void *p;
376 	int i;
377 
378 	for (p = memmap.map, i = 0;
379 	     p < memmap.map_end;
380 	     p += memmap.desc_size, i++) {
381 		md = p;
382 		pr_info("mem%02u: type=%u, attr=0x%llx, "
383 			"range=[0x%016llx-0x%016llx) (%lluMB)\n",
384 			i, md->type, md->attribute, md->phys_addr,
385 			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
386 			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
387 	}
388 }
389 #endif  /*  EFI_DEBUG  */
390 
391 void __init efi_reserve_boot_services(void)
392 {
393 	void *p;
394 
395 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
396 		efi_memory_desc_t *md = p;
397 		u64 start = md->phys_addr;
398 		u64 size = md->num_pages << EFI_PAGE_SHIFT;
399 
400 		if (md->type != EFI_BOOT_SERVICES_CODE &&
401 		    md->type != EFI_BOOT_SERVICES_DATA)
402 			continue;
403 		/* Only reserve where possible:
404 		 * - Not within any already allocated areas
405 		 * - Not over any memory area (really needed, if above?)
406 		 * - Not within any part of the kernel
407 		 * - Not the bios reserved area
408 		*/
409 		if ((start+size >= virt_to_phys(_text)
410 				&& start <= virt_to_phys(_end)) ||
411 			!e820_all_mapped(start, start+size, E820_RAM) ||
412 			memblock_is_region_reserved(start, size)) {
413 			/* Could not reserve, skip it */
414 			md->num_pages = 0;
415 			memblock_dbg("Could not reserve boot range "
416 					"[0x%010llx-0x%010llx]\n",
417 						start, start+size-1);
418 		} else
419 			memblock_reserve(start, size);
420 	}
421 }
422 
423 static void __init efi_unmap_memmap(void)
424 {
425 	if (memmap.map) {
426 		early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
427 		memmap.map = NULL;
428 	}
429 }
430 
431 void __init efi_free_boot_services(void)
432 {
433 	void *p;
434 
435 	if (!efi_native)
436 		return;
437 
438 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
439 		efi_memory_desc_t *md = p;
440 		unsigned long long start = md->phys_addr;
441 		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
442 
443 		if (md->type != EFI_BOOT_SERVICES_CODE &&
444 		    md->type != EFI_BOOT_SERVICES_DATA)
445 			continue;
446 
447 		/* Could not reserve boot area */
448 		if (!size)
449 			continue;
450 
451 		free_bootmem_late(start, size);
452 	}
453 
454 	efi_unmap_memmap();
455 }
456 
457 static int __init efi_systab_init(void *phys)
458 {
459 	if (efi_64bit) {
460 		efi_system_table_64_t *systab64;
461 		u64 tmp = 0;
462 
463 		systab64 = early_ioremap((unsigned long)phys,
464 					 sizeof(*systab64));
465 		if (systab64 == NULL) {
466 			pr_err("Couldn't map the system table!\n");
467 			return -ENOMEM;
468 		}
469 
470 		efi_systab.hdr = systab64->hdr;
471 		efi_systab.fw_vendor = systab64->fw_vendor;
472 		tmp |= systab64->fw_vendor;
473 		efi_systab.fw_revision = systab64->fw_revision;
474 		efi_systab.con_in_handle = systab64->con_in_handle;
475 		tmp |= systab64->con_in_handle;
476 		efi_systab.con_in = systab64->con_in;
477 		tmp |= systab64->con_in;
478 		efi_systab.con_out_handle = systab64->con_out_handle;
479 		tmp |= systab64->con_out_handle;
480 		efi_systab.con_out = systab64->con_out;
481 		tmp |= systab64->con_out;
482 		efi_systab.stderr_handle = systab64->stderr_handle;
483 		tmp |= systab64->stderr_handle;
484 		efi_systab.stderr = systab64->stderr;
485 		tmp |= systab64->stderr;
486 		efi_systab.runtime = (void *)(unsigned long)systab64->runtime;
487 		tmp |= systab64->runtime;
488 		efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
489 		tmp |= systab64->boottime;
490 		efi_systab.nr_tables = systab64->nr_tables;
491 		efi_systab.tables = systab64->tables;
492 		tmp |= systab64->tables;
493 
494 		early_iounmap(systab64, sizeof(*systab64));
495 #ifdef CONFIG_X86_32
496 		if (tmp >> 32) {
497 			pr_err("EFI data located above 4GB, disabling EFI.\n");
498 			return -EINVAL;
499 		}
500 #endif
501 	} else {
502 		efi_system_table_32_t *systab32;
503 
504 		systab32 = early_ioremap((unsigned long)phys,
505 					 sizeof(*systab32));
506 		if (systab32 == NULL) {
507 			pr_err("Couldn't map the system table!\n");
508 			return -ENOMEM;
509 		}
510 
511 		efi_systab.hdr = systab32->hdr;
512 		efi_systab.fw_vendor = systab32->fw_vendor;
513 		efi_systab.fw_revision = systab32->fw_revision;
514 		efi_systab.con_in_handle = systab32->con_in_handle;
515 		efi_systab.con_in = systab32->con_in;
516 		efi_systab.con_out_handle = systab32->con_out_handle;
517 		efi_systab.con_out = systab32->con_out;
518 		efi_systab.stderr_handle = systab32->stderr_handle;
519 		efi_systab.stderr = systab32->stderr;
520 		efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
521 		efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
522 		efi_systab.nr_tables = systab32->nr_tables;
523 		efi_systab.tables = systab32->tables;
524 
525 		early_iounmap(systab32, sizeof(*systab32));
526 	}
527 
528 	efi.systab = &efi_systab;
529 
530 	/*
531 	 * Verify the EFI Table
532 	 */
533 	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
534 		pr_err("System table signature incorrect!\n");
535 		return -EINVAL;
536 	}
537 	if ((efi.systab->hdr.revision >> 16) == 0)
538 		pr_err("Warning: System table version "
539 		       "%d.%02d, expected 1.00 or greater!\n",
540 		       efi.systab->hdr.revision >> 16,
541 		       efi.systab->hdr.revision & 0xffff);
542 
543 	return 0;
544 }
545 
546 static int __init efi_config_init(u64 tables, int nr_tables)
547 {
548 	void *config_tables, *tablep;
549 	int i, sz;
550 
551 	if (efi_64bit)
552 		sz = sizeof(efi_config_table_64_t);
553 	else
554 		sz = sizeof(efi_config_table_32_t);
555 
556 	/*
557 	 * Let's see what config tables the firmware passed to us.
558 	 */
559 	config_tables = early_ioremap(tables, nr_tables * sz);
560 	if (config_tables == NULL) {
561 		pr_err("Could not map Configuration table!\n");
562 		return -ENOMEM;
563 	}
564 
565 	tablep = config_tables;
566 	pr_info("");
567 	for (i = 0; i < efi.systab->nr_tables; i++) {
568 		efi_guid_t guid;
569 		unsigned long table;
570 
571 		if (efi_64bit) {
572 			u64 table64;
573 			guid = ((efi_config_table_64_t *)tablep)->guid;
574 			table64 = ((efi_config_table_64_t *)tablep)->table;
575 			table = table64;
576 #ifdef CONFIG_X86_32
577 			if (table64 >> 32) {
578 				pr_cont("\n");
579 				pr_err("Table located above 4GB, disabling EFI.\n");
580 				early_iounmap(config_tables,
581 					      efi.systab->nr_tables * sz);
582 				return -EINVAL;
583 			}
584 #endif
585 		} else {
586 			guid = ((efi_config_table_32_t *)tablep)->guid;
587 			table = ((efi_config_table_32_t *)tablep)->table;
588 		}
589 		if (!efi_guidcmp(guid, MPS_TABLE_GUID)) {
590 			efi.mps = table;
591 			pr_cont(" MPS=0x%lx ", table);
592 		} else if (!efi_guidcmp(guid, ACPI_20_TABLE_GUID)) {
593 			efi.acpi20 = table;
594 			pr_cont(" ACPI 2.0=0x%lx ", table);
595 		} else if (!efi_guidcmp(guid, ACPI_TABLE_GUID)) {
596 			efi.acpi = table;
597 			pr_cont(" ACPI=0x%lx ", table);
598 		} else if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID)) {
599 			efi.smbios = table;
600 			pr_cont(" SMBIOS=0x%lx ", table);
601 #ifdef CONFIG_X86_UV
602 		} else if (!efi_guidcmp(guid, UV_SYSTEM_TABLE_GUID)) {
603 			efi.uv_systab = table;
604 			pr_cont(" UVsystab=0x%lx ", table);
605 #endif
606 		} else if (!efi_guidcmp(guid, HCDP_TABLE_GUID)) {
607 			efi.hcdp = table;
608 			pr_cont(" HCDP=0x%lx ", table);
609 		} else if (!efi_guidcmp(guid, UGA_IO_PROTOCOL_GUID)) {
610 			efi.uga = table;
611 			pr_cont(" UGA=0x%lx ", table);
612 		}
613 		tablep += sz;
614 	}
615 	pr_cont("\n");
616 	early_iounmap(config_tables, efi.systab->nr_tables * sz);
617 	return 0;
618 }
619 
620 static int __init efi_runtime_init(void)
621 {
622 	efi_runtime_services_t *runtime;
623 
624 	/*
625 	 * Check out the runtime services table. We need to map
626 	 * the runtime services table so that we can grab the physical
627 	 * address of several of the EFI runtime functions, needed to
628 	 * set the firmware into virtual mode.
629 	 */
630 	runtime = early_ioremap((unsigned long)efi.systab->runtime,
631 				sizeof(efi_runtime_services_t));
632 	if (!runtime) {
633 		pr_err("Could not map the runtime service table!\n");
634 		return -ENOMEM;
635 	}
636 	/*
637 	 * We will only need *early* access to the following
638 	 * two EFI runtime services before set_virtual_address_map
639 	 * is invoked.
640 	 */
641 	efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
642 	efi_phys.set_virtual_address_map =
643 		(efi_set_virtual_address_map_t *)
644 		runtime->set_virtual_address_map;
645 	/*
646 	 * Make efi_get_time can be called before entering
647 	 * virtual mode.
648 	 */
649 	efi.get_time = phys_efi_get_time;
650 	early_iounmap(runtime, sizeof(efi_runtime_services_t));
651 
652 	return 0;
653 }
654 
655 static int __init efi_memmap_init(void)
656 {
657 	/* Map the EFI memory map */
658 	memmap.map = early_ioremap((unsigned long)memmap.phys_map,
659 				   memmap.nr_map * memmap.desc_size);
660 	if (memmap.map == NULL) {
661 		pr_err("Could not map the memory map!\n");
662 		return -ENOMEM;
663 	}
664 	memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
665 
666 	if (add_efi_memmap)
667 		do_add_efi_memmap();
668 
669 	return 0;
670 }
671 
672 void __init efi_init(void)
673 {
674 	efi_char16_t *c16;
675 	char vendor[100] = "unknown";
676 	int i = 0;
677 	void *tmp;
678 
679 #ifdef CONFIG_X86_32
680 	if (boot_params.efi_info.efi_systab_hi ||
681 	    boot_params.efi_info.efi_memmap_hi) {
682 		pr_info("Table located above 4GB, disabling EFI.\n");
683 		efi_enabled = 0;
684 		return;
685 	}
686 	efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
687 	efi_native = !efi_64bit;
688 #else
689 	efi_phys.systab = (efi_system_table_t *)
690 			  (boot_params.efi_info.efi_systab |
691 			  ((__u64)boot_params.efi_info.efi_systab_hi<<32));
692 	efi_native = efi_64bit;
693 #endif
694 
695 	if (efi_systab_init(efi_phys.systab)) {
696 		efi_enabled = 0;
697 		return;
698 	}
699 
700 	/*
701 	 * Show what we know for posterity
702 	 */
703 	c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
704 	if (c16) {
705 		for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
706 			vendor[i] = *c16++;
707 		vendor[i] = '\0';
708 	} else
709 		pr_err("Could not map the firmware vendor!\n");
710 	early_iounmap(tmp, 2);
711 
712 	pr_info("EFI v%u.%.02u by %s\n",
713 		efi.systab->hdr.revision >> 16,
714 		efi.systab->hdr.revision & 0xffff, vendor);
715 
716 	if (efi_config_init(efi.systab->tables, efi.systab->nr_tables)) {
717 		efi_enabled = 0;
718 		return;
719 	}
720 
721 	/*
722 	 * Note: We currently don't support runtime services on an EFI
723 	 * that doesn't match the kernel 32/64-bit mode.
724 	 */
725 
726 	if (!efi_native)
727 		pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
728 	else if (efi_runtime_init()) {
729 		efi_enabled = 0;
730 		return;
731 	}
732 
733 	if (efi_memmap_init()) {
734 		efi_enabled = 0;
735 		return;
736 	}
737 #ifdef CONFIG_X86_32
738 	if (efi_native) {
739 		x86_platform.get_wallclock = efi_get_time;
740 		x86_platform.set_wallclock = efi_set_rtc_mmss;
741 	}
742 #endif
743 
744 #if EFI_DEBUG
745 	print_efi_memmap();
746 #endif
747 }
748 
749 void __init efi_late_init(void)
750 {
751 	efi_bgrt_init();
752 }
753 
754 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
755 {
756 	u64 addr, npages;
757 
758 	addr = md->virt_addr;
759 	npages = md->num_pages;
760 
761 	memrange_efi_to_native(&addr, &npages);
762 
763 	if (executable)
764 		set_memory_x(addr, npages);
765 	else
766 		set_memory_nx(addr, npages);
767 }
768 
769 static void __init runtime_code_page_mkexec(void)
770 {
771 	efi_memory_desc_t *md;
772 	void *p;
773 
774 	/* Make EFI runtime service code area executable */
775 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
776 		md = p;
777 
778 		if (md->type != EFI_RUNTIME_SERVICES_CODE)
779 			continue;
780 
781 		efi_set_executable(md, true);
782 	}
783 }
784 
785 /*
786  * We can't ioremap data in EFI boot services RAM, because we've already mapped
787  * it as RAM.  So, look it up in the existing EFI memory map instead.  Only
788  * callable after efi_enter_virtual_mode and before efi_free_boot_services.
789  */
790 void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
791 {
792 	void *p;
793 	if (WARN_ON(!memmap.map))
794 		return NULL;
795 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
796 		efi_memory_desc_t *md = p;
797 		u64 size = md->num_pages << EFI_PAGE_SHIFT;
798 		u64 end = md->phys_addr + size;
799 		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
800 		    md->type != EFI_BOOT_SERVICES_CODE &&
801 		    md->type != EFI_BOOT_SERVICES_DATA)
802 			continue;
803 		if (!md->virt_addr)
804 			continue;
805 		if (phys_addr >= md->phys_addr && phys_addr < end) {
806 			phys_addr += md->virt_addr - md->phys_addr;
807 			return (__force void __iomem *)(unsigned long)phys_addr;
808 		}
809 	}
810 	return NULL;
811 }
812 
813 /*
814  * This function will switch the EFI runtime services to virtual mode.
815  * Essentially, look through the EFI memmap and map every region that
816  * has the runtime attribute bit set in its memory descriptor and update
817  * that memory descriptor with the virtual address obtained from ioremap().
818  * This enables the runtime services to be called without having to
819  * thunk back into physical mode for every invocation.
820  */
821 void __init efi_enter_virtual_mode(void)
822 {
823 	efi_memory_desc_t *md, *prev_md = NULL;
824 	efi_status_t status;
825 	unsigned long size;
826 	u64 end, systab, addr, npages, end_pfn;
827 	void *p, *va, *new_memmap = NULL;
828 	int count = 0;
829 
830 	efi.systab = NULL;
831 
832 	/*
833 	 * We don't do virtual mode, since we don't do runtime services, on
834 	 * non-native EFI
835 	 */
836 
837 	if (!efi_native) {
838 		efi_unmap_memmap();
839 		return;
840 	}
841 
842 	/* Merge contiguous regions of the same type and attribute */
843 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
844 		u64 prev_size;
845 		md = p;
846 
847 		if (!prev_md) {
848 			prev_md = md;
849 			continue;
850 		}
851 
852 		if (prev_md->type != md->type ||
853 		    prev_md->attribute != md->attribute) {
854 			prev_md = md;
855 			continue;
856 		}
857 
858 		prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
859 
860 		if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
861 			prev_md->num_pages += md->num_pages;
862 			md->type = EFI_RESERVED_TYPE;
863 			md->attribute = 0;
864 			continue;
865 		}
866 		prev_md = md;
867 	}
868 
869 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
870 		md = p;
871 		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
872 		    md->type != EFI_BOOT_SERVICES_CODE &&
873 		    md->type != EFI_BOOT_SERVICES_DATA)
874 			continue;
875 
876 		size = md->num_pages << EFI_PAGE_SHIFT;
877 		end = md->phys_addr + size;
878 
879 		end_pfn = PFN_UP(end);
880 		if (end_pfn <= max_low_pfn_mapped
881 		    || (end_pfn > (1UL << (32 - PAGE_SHIFT))
882 			&& end_pfn <= max_pfn_mapped))
883 			va = __va(md->phys_addr);
884 		else
885 			va = efi_ioremap(md->phys_addr, size, md->type);
886 
887 		md->virt_addr = (u64) (unsigned long) va;
888 
889 		if (!va) {
890 			pr_err("ioremap of 0x%llX failed!\n",
891 			       (unsigned long long)md->phys_addr);
892 			continue;
893 		}
894 
895 		if (!(md->attribute & EFI_MEMORY_WB)) {
896 			addr = md->virt_addr;
897 			npages = md->num_pages;
898 			memrange_efi_to_native(&addr, &npages);
899 			set_memory_uc(addr, npages);
900 		}
901 
902 		systab = (u64) (unsigned long) efi_phys.systab;
903 		if (md->phys_addr <= systab && systab < end) {
904 			systab += md->virt_addr - md->phys_addr;
905 			efi.systab = (efi_system_table_t *) (unsigned long) systab;
906 		}
907 		new_memmap = krealloc(new_memmap,
908 				      (count + 1) * memmap.desc_size,
909 				      GFP_KERNEL);
910 		memcpy(new_memmap + (count * memmap.desc_size), md,
911 		       memmap.desc_size);
912 		count++;
913 	}
914 
915 	BUG_ON(!efi.systab);
916 
917 	status = phys_efi_set_virtual_address_map(
918 		memmap.desc_size * count,
919 		memmap.desc_size,
920 		memmap.desc_version,
921 		(efi_memory_desc_t *)__pa(new_memmap));
922 
923 	if (status != EFI_SUCCESS) {
924 		pr_alert("Unable to switch EFI into virtual mode "
925 			 "(status=%lx)!\n", status);
926 		panic("EFI call to SetVirtualAddressMap() failed!");
927 	}
928 
929 	/*
930 	 * Now that EFI is in virtual mode, update the function
931 	 * pointers in the runtime service table to the new virtual addresses.
932 	 *
933 	 * Call EFI services through wrapper functions.
934 	 */
935 	efi.runtime_version = efi_systab.fw_revision;
936 	efi.get_time = virt_efi_get_time;
937 	efi.set_time = virt_efi_set_time;
938 	efi.get_wakeup_time = virt_efi_get_wakeup_time;
939 	efi.set_wakeup_time = virt_efi_set_wakeup_time;
940 	efi.get_variable = virt_efi_get_variable;
941 	efi.get_next_variable = virt_efi_get_next_variable;
942 	efi.set_variable = virt_efi_set_variable;
943 	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
944 	efi.reset_system = virt_efi_reset_system;
945 	efi.set_virtual_address_map = NULL;
946 	efi.query_variable_info = virt_efi_query_variable_info;
947 	efi.update_capsule = virt_efi_update_capsule;
948 	efi.query_capsule_caps = virt_efi_query_capsule_caps;
949 	if (__supported_pte_mask & _PAGE_NX)
950 		runtime_code_page_mkexec();
951 
952 	kfree(new_memmap);
953 }
954 
955 /*
956  * Convenience functions to obtain memory types and attributes
957  */
958 u32 efi_mem_type(unsigned long phys_addr)
959 {
960 	efi_memory_desc_t *md;
961 	void *p;
962 
963 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
964 		md = p;
965 		if ((md->phys_addr <= phys_addr) &&
966 		    (phys_addr < (md->phys_addr +
967 				  (md->num_pages << EFI_PAGE_SHIFT))))
968 			return md->type;
969 	}
970 	return 0;
971 }
972 
973 u64 efi_mem_attributes(unsigned long phys_addr)
974 {
975 	efi_memory_desc_t *md;
976 	void *p;
977 
978 	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
979 		md = p;
980 		if ((md->phys_addr <= phys_addr) &&
981 		    (phys_addr < (md->phys_addr +
982 				  (md->num_pages << EFI_PAGE_SHIFT))))
983 			return md->attribute;
984 	}
985 	return 0;
986 }
987