1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Common EFI (Extensible Firmware Interface) support functions
4 * Based on Extensible Firmware Interface Specification version 1.0
5 *
6 * Copyright (C) 1999 VA Linux Systems
7 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
8 * Copyright (C) 1999-2002 Hewlett-Packard Co.
9 * David Mosberger-Tang <davidm@hpl.hp.com>
10 * Stephane Eranian <eranian@hpl.hp.com>
11 * Copyright (C) 2005-2008 Intel Co.
12 * Fenghua Yu <fenghua.yu@intel.com>
13 * Bibo Mao <bibo.mao@intel.com>
14 * Chandramouli Narayanan <mouli@linux.intel.com>
15 * Huang Ying <ying.huang@intel.com>
16 * Copyright (C) 2013 SuSE Labs
17 * Borislav Petkov <bp@suse.de> - runtime services VA mapping
18 *
19 * Copied from efi_32.c to eliminate the duplicated code between EFI
20 * 32/64 support code. --ying 2007-10-26
21 *
22 * All EFI Runtime Services are not implemented yet as EFI only
23 * supports physical mode addressing on SoftSDV. This is to be fixed
24 * in a future version. --drummond 1999-07-20
25 *
26 * Implemented EFI runtime services and virtual mode calls. --davidm
27 *
28 * Goutham Rao: <goutham.rao@intel.com>
29 * Skip non-WB memory and ignore empty memory ranges.
30 */
31
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34 #include <linux/kernel.h>
35 #include <linux/init.h>
36 #include <linux/efi.h>
37 #include <linux/efi-bgrt.h>
38 #include <linux/export.h>
39 #include <linux/memblock.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/uaccess.h>
43 #include <linux/time.h>
44 #include <linux/io.h>
45 #include <linux/reboot.h>
46 #include <linux/bcd.h>
47
48 #include <asm/setup.h>
49 #include <asm/efi.h>
50 #include <asm/e820/api.h>
51 #include <asm/time.h>
52 #include <asm/tlbflush.h>
53 #include <asm/x86_init.h>
54 #include <asm/uv/uv.h>
55
56 static unsigned long efi_systab_phys __initdata;
57 static unsigned long prop_phys = EFI_INVALID_TABLE_ADDR;
58 static unsigned long uga_phys = EFI_INVALID_TABLE_ADDR;
59 static unsigned long efi_runtime, efi_nr_tables;
60
61 unsigned long efi_fw_vendor, efi_config_table;
62
63 static const efi_config_table_type_t arch_tables[] __initconst = {
64 {EFI_PROPERTIES_TABLE_GUID, &prop_phys, "PROP" },
65 {UGA_IO_PROTOCOL_GUID, &uga_phys, "UGA" },
66 #ifdef CONFIG_X86_UV
67 {UV_SYSTEM_TABLE_GUID, &uv_systab_phys, "UVsystab" },
68 #endif
69 {},
70 };
71
72 static const unsigned long * const efi_tables[] = {
73 &efi.acpi,
74 &efi.acpi20,
75 &efi.smbios,
76 &efi.smbios3,
77 &uga_phys,
78 #ifdef CONFIG_X86_UV
79 &uv_systab_phys,
80 #endif
81 &efi_fw_vendor,
82 &efi_runtime,
83 &efi_config_table,
84 &efi.esrt,
85 &prop_phys,
86 &efi_mem_attr_table,
87 #ifdef CONFIG_EFI_RCI2_TABLE
88 &rci2_table_phys,
89 #endif
90 &efi.tpm_log,
91 &efi.tpm_final_log,
92 &efi_rng_seed,
93 #ifdef CONFIG_LOAD_UEFI_KEYS
94 &efi.mokvar_table,
95 #endif
96 };
97
98 u64 efi_setup; /* efi setup_data physical address */
99
100 static int add_efi_memmap __initdata;
setup_add_efi_memmap(char * arg)101 static int __init setup_add_efi_memmap(char *arg)
102 {
103 add_efi_memmap = 1;
104 return 0;
105 }
106 early_param("add_efi_memmap", setup_add_efi_memmap);
107
efi_find_mirror(void)108 void __init efi_find_mirror(void)
109 {
110 efi_memory_desc_t *md;
111 u64 mirror_size = 0, total_size = 0;
112
113 if (!efi_enabled(EFI_MEMMAP))
114 return;
115
116 for_each_efi_memory_desc(md) {
117 unsigned long long start = md->phys_addr;
118 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
119
120 total_size += size;
121 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
122 memblock_mark_mirror(start, size);
123 mirror_size += size;
124 }
125 }
126 if (mirror_size)
127 pr_info("Memory: %lldM/%lldM mirrored memory\n",
128 mirror_size>>20, total_size>>20);
129 }
130
131 /*
132 * Tell the kernel about the EFI memory map. This might include
133 * more than the max 128 entries that can fit in the passed in e820
134 * legacy (zeropage) memory map, but the kernel's e820 table can hold
135 * E820_MAX_ENTRIES.
136 */
137
do_add_efi_memmap(void)138 static void __init do_add_efi_memmap(void)
139 {
140 efi_memory_desc_t *md;
141
142 if (!efi_enabled(EFI_MEMMAP))
143 return;
144
145 for_each_efi_memory_desc(md) {
146 unsigned long long start = md->phys_addr;
147 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
148 int e820_type;
149
150 switch (md->type) {
151 case EFI_LOADER_CODE:
152 case EFI_LOADER_DATA:
153 case EFI_BOOT_SERVICES_CODE:
154 case EFI_BOOT_SERVICES_DATA:
155 case EFI_CONVENTIONAL_MEMORY:
156 if (efi_soft_reserve_enabled()
157 && (md->attribute & EFI_MEMORY_SP))
158 e820_type = E820_TYPE_SOFT_RESERVED;
159 else if (md->attribute & EFI_MEMORY_WB)
160 e820_type = E820_TYPE_RAM;
161 else
162 e820_type = E820_TYPE_RESERVED;
163 break;
164 case EFI_ACPI_RECLAIM_MEMORY:
165 e820_type = E820_TYPE_ACPI;
166 break;
167 case EFI_ACPI_MEMORY_NVS:
168 e820_type = E820_TYPE_NVS;
169 break;
170 case EFI_UNUSABLE_MEMORY:
171 e820_type = E820_TYPE_UNUSABLE;
172 break;
173 case EFI_PERSISTENT_MEMORY:
174 e820_type = E820_TYPE_PMEM;
175 break;
176 default:
177 /*
178 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
179 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
180 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
181 */
182 e820_type = E820_TYPE_RESERVED;
183 break;
184 }
185
186 e820__range_add(start, size, e820_type);
187 }
188 e820__update_table(e820_table);
189 }
190
191 /*
192 * Given add_efi_memmap defaults to 0 and there there is no alternative
193 * e820 mechanism for soft-reserved memory, import the full EFI memory
194 * map if soft reservations are present and enabled. Otherwise, the
195 * mechanism to disable the kernel's consideration of EFI_MEMORY_SP is
196 * the efi=nosoftreserve option.
197 */
do_efi_soft_reserve(void)198 static bool do_efi_soft_reserve(void)
199 {
200 efi_memory_desc_t *md;
201
202 if (!efi_enabled(EFI_MEMMAP))
203 return false;
204
205 if (!efi_soft_reserve_enabled())
206 return false;
207
208 for_each_efi_memory_desc(md)
209 if (md->type == EFI_CONVENTIONAL_MEMORY &&
210 (md->attribute & EFI_MEMORY_SP))
211 return true;
212 return false;
213 }
214
efi_memblock_x86_reserve_range(void)215 int __init efi_memblock_x86_reserve_range(void)
216 {
217 struct efi_info *e = &boot_params.efi_info;
218 struct efi_memory_map_data data;
219 phys_addr_t pmap;
220 int rv;
221
222 if (efi_enabled(EFI_PARAVIRT))
223 return 0;
224
225 /* Can't handle firmware tables above 4GB on i386 */
226 if (IS_ENABLED(CONFIG_X86_32) && e->efi_memmap_hi > 0) {
227 pr_err("Memory map is above 4GB, disabling EFI.\n");
228 return -EINVAL;
229 }
230 pmap = (phys_addr_t)(e->efi_memmap | ((u64)e->efi_memmap_hi << 32));
231
232 data.phys_map = pmap;
233 data.size = e->efi_memmap_size;
234 data.desc_size = e->efi_memdesc_size;
235 data.desc_version = e->efi_memdesc_version;
236
237 rv = efi_memmap_init_early(&data);
238 if (rv)
239 return rv;
240
241 if (add_efi_memmap || do_efi_soft_reserve())
242 do_add_efi_memmap();
243
244 efi_fake_memmap_early();
245
246 WARN(efi.memmap.desc_version != 1,
247 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
248 efi.memmap.desc_version);
249
250 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
251 set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags);
252
253 return 0;
254 }
255
256 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
257 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
258 #define U64_HIGH_BIT (~(U64_MAX >> 1))
259
efi_memmap_entry_valid(const efi_memory_desc_t * md,int i)260 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
261 {
262 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
263 u64 end_hi = 0;
264 char buf[64];
265
266 if (md->num_pages == 0) {
267 end = 0;
268 } else if (md->num_pages > EFI_PAGES_MAX ||
269 EFI_PAGES_MAX - md->num_pages <
270 (md->phys_addr >> EFI_PAGE_SHIFT)) {
271 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
272 >> OVERFLOW_ADDR_SHIFT;
273
274 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
275 end_hi += 1;
276 } else {
277 return true;
278 }
279
280 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
281
282 if (end_hi) {
283 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
284 i, efi_md_typeattr_format(buf, sizeof(buf), md),
285 md->phys_addr, end_hi, end);
286 } else {
287 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
288 i, efi_md_typeattr_format(buf, sizeof(buf), md),
289 md->phys_addr, end);
290 }
291 return false;
292 }
293
efi_clean_memmap(void)294 static void __init efi_clean_memmap(void)
295 {
296 efi_memory_desc_t *out = efi.memmap.map;
297 const efi_memory_desc_t *in = out;
298 const efi_memory_desc_t *end = efi.memmap.map_end;
299 int i, n_removal;
300
301 for (i = n_removal = 0; in < end; i++) {
302 if (efi_memmap_entry_valid(in, i)) {
303 if (out != in)
304 memcpy(out, in, efi.memmap.desc_size);
305 out = (void *)out + efi.memmap.desc_size;
306 } else {
307 n_removal++;
308 }
309 in = (void *)in + efi.memmap.desc_size;
310 }
311
312 if (n_removal > 0) {
313 struct efi_memory_map_data data = {
314 .phys_map = efi.memmap.phys_map,
315 .desc_version = efi.memmap.desc_version,
316 .desc_size = efi.memmap.desc_size,
317 .size = efi.memmap.desc_size * (efi.memmap.nr_map - n_removal),
318 .flags = 0,
319 };
320
321 pr_warn("Removing %d invalid memory map entries.\n", n_removal);
322 efi_memmap_install(&data);
323 }
324 }
325
efi_print_memmap(void)326 void __init efi_print_memmap(void)
327 {
328 efi_memory_desc_t *md;
329 int i = 0;
330
331 for_each_efi_memory_desc(md) {
332 char buf[64];
333
334 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
335 i++, efi_md_typeattr_format(buf, sizeof(buf), md),
336 md->phys_addr,
337 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
338 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
339 }
340 }
341
efi_systab_init(unsigned long phys)342 static int __init efi_systab_init(unsigned long phys)
343 {
344 int size = efi_enabled(EFI_64BIT) ? sizeof(efi_system_table_64_t)
345 : sizeof(efi_system_table_32_t);
346 const efi_table_hdr_t *hdr;
347 bool over4g = false;
348 void *p;
349 int ret;
350
351 hdr = p = early_memremap_ro(phys, size);
352 if (p == NULL) {
353 pr_err("Couldn't map the system table!\n");
354 return -ENOMEM;
355 }
356
357 ret = efi_systab_check_header(hdr, 1);
358 if (ret) {
359 early_memunmap(p, size);
360 return ret;
361 }
362
363 if (efi_enabled(EFI_64BIT)) {
364 const efi_system_table_64_t *systab64 = p;
365
366 efi_runtime = systab64->runtime;
367 over4g = systab64->runtime > U32_MAX;
368
369 if (efi_setup) {
370 struct efi_setup_data *data;
371
372 data = early_memremap_ro(efi_setup, sizeof(*data));
373 if (!data) {
374 early_memunmap(p, size);
375 return -ENOMEM;
376 }
377
378 efi_fw_vendor = (unsigned long)data->fw_vendor;
379 efi_config_table = (unsigned long)data->tables;
380
381 over4g |= data->fw_vendor > U32_MAX ||
382 data->tables > U32_MAX;
383
384 early_memunmap(data, sizeof(*data));
385 } else {
386 efi_fw_vendor = systab64->fw_vendor;
387 efi_config_table = systab64->tables;
388
389 over4g |= systab64->fw_vendor > U32_MAX ||
390 systab64->tables > U32_MAX;
391 }
392 efi_nr_tables = systab64->nr_tables;
393 } else {
394 const efi_system_table_32_t *systab32 = p;
395
396 efi_fw_vendor = systab32->fw_vendor;
397 efi_runtime = systab32->runtime;
398 efi_config_table = systab32->tables;
399 efi_nr_tables = systab32->nr_tables;
400 }
401
402 efi.runtime_version = hdr->revision;
403
404 efi_systab_report_header(hdr, efi_fw_vendor);
405 early_memunmap(p, size);
406
407 if (IS_ENABLED(CONFIG_X86_32) && over4g) {
408 pr_err("EFI data located above 4GB, disabling EFI.\n");
409 return -EINVAL;
410 }
411
412 return 0;
413 }
414
efi_config_init(const efi_config_table_type_t * arch_tables)415 static int __init efi_config_init(const efi_config_table_type_t *arch_tables)
416 {
417 void *config_tables;
418 int sz, ret;
419
420 if (efi_nr_tables == 0)
421 return 0;
422
423 if (efi_enabled(EFI_64BIT))
424 sz = sizeof(efi_config_table_64_t);
425 else
426 sz = sizeof(efi_config_table_32_t);
427
428 /*
429 * Let's see what config tables the firmware passed to us.
430 */
431 config_tables = early_memremap(efi_config_table, efi_nr_tables * sz);
432 if (config_tables == NULL) {
433 pr_err("Could not map Configuration table!\n");
434 return -ENOMEM;
435 }
436
437 ret = efi_config_parse_tables(config_tables, efi_nr_tables,
438 arch_tables);
439
440 early_memunmap(config_tables, efi_nr_tables * sz);
441 return ret;
442 }
443
efi_init(void)444 void __init efi_init(void)
445 {
446 if (IS_ENABLED(CONFIG_X86_32) &&
447 (boot_params.efi_info.efi_systab_hi ||
448 boot_params.efi_info.efi_memmap_hi)) {
449 pr_info("Table located above 4GB, disabling EFI.\n");
450 return;
451 }
452
453 efi_systab_phys = boot_params.efi_info.efi_systab |
454 ((__u64)boot_params.efi_info.efi_systab_hi << 32);
455
456 if (efi_systab_init(efi_systab_phys))
457 return;
458
459 if (efi_reuse_config(efi_config_table, efi_nr_tables))
460 return;
461
462 if (efi_config_init(arch_tables))
463 return;
464
465 /*
466 * Note: We currently don't support runtime services on an EFI
467 * that doesn't match the kernel 32/64-bit mode.
468 */
469
470 if (!efi_runtime_supported())
471 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
472
473 if (!efi_runtime_supported() || efi_runtime_disabled()) {
474 efi_memmap_unmap();
475 return;
476 }
477
478 /* Parse the EFI Properties table if it exists */
479 if (prop_phys != EFI_INVALID_TABLE_ADDR) {
480 efi_properties_table_t *tbl;
481
482 tbl = early_memremap_ro(prop_phys, sizeof(*tbl));
483 if (tbl == NULL) {
484 pr_err("Could not map Properties table!\n");
485 } else {
486 if (tbl->memory_protection_attribute &
487 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
488 set_bit(EFI_NX_PE_DATA, &efi.flags);
489
490 early_memunmap(tbl, sizeof(*tbl));
491 }
492 }
493
494 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
495 efi_clean_memmap();
496
497 if (efi_enabled(EFI_DBG))
498 efi_print_memmap();
499 }
500
501 /* Merge contiguous regions of the same type and attribute */
efi_merge_regions(void)502 static void __init efi_merge_regions(void)
503 {
504 efi_memory_desc_t *md, *prev_md = NULL;
505
506 for_each_efi_memory_desc(md) {
507 u64 prev_size;
508
509 if (!prev_md) {
510 prev_md = md;
511 continue;
512 }
513
514 if (prev_md->type != md->type ||
515 prev_md->attribute != md->attribute) {
516 prev_md = md;
517 continue;
518 }
519
520 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
521
522 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
523 prev_md->num_pages += md->num_pages;
524 md->type = EFI_RESERVED_TYPE;
525 md->attribute = 0;
526 continue;
527 }
528 prev_md = md;
529 }
530 }
531
realloc_pages(void * old_memmap,int old_shift)532 static void *realloc_pages(void *old_memmap, int old_shift)
533 {
534 void *ret;
535
536 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
537 if (!ret)
538 goto out;
539
540 /*
541 * A first-time allocation doesn't have anything to copy.
542 */
543 if (!old_memmap)
544 return ret;
545
546 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
547
548 out:
549 free_pages((unsigned long)old_memmap, old_shift);
550 return ret;
551 }
552
553 /*
554 * Iterate the EFI memory map in reverse order because the regions
555 * will be mapped top-down. The end result is the same as if we had
556 * mapped things forward, but doesn't require us to change the
557 * existing implementation of efi_map_region().
558 */
efi_map_next_entry_reverse(void * entry)559 static inline void *efi_map_next_entry_reverse(void *entry)
560 {
561 /* Initial call */
562 if (!entry)
563 return efi.memmap.map_end - efi.memmap.desc_size;
564
565 entry -= efi.memmap.desc_size;
566 if (entry < efi.memmap.map)
567 return NULL;
568
569 return entry;
570 }
571
572 /*
573 * efi_map_next_entry - Return the next EFI memory map descriptor
574 * @entry: Previous EFI memory map descriptor
575 *
576 * This is a helper function to iterate over the EFI memory map, which
577 * we do in different orders depending on the current configuration.
578 *
579 * To begin traversing the memory map @entry must be %NULL.
580 *
581 * Returns %NULL when we reach the end of the memory map.
582 */
efi_map_next_entry(void * entry)583 static void *efi_map_next_entry(void *entry)
584 {
585 if (efi_enabled(EFI_64BIT)) {
586 /*
587 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
588 * config table feature requires us to map all entries
589 * in the same order as they appear in the EFI memory
590 * map. That is to say, entry N must have a lower
591 * virtual address than entry N+1. This is because the
592 * firmware toolchain leaves relative references in
593 * the code/data sections, which are split and become
594 * separate EFI memory regions. Mapping things
595 * out-of-order leads to the firmware accessing
596 * unmapped addresses.
597 *
598 * Since we need to map things this way whether or not
599 * the kernel actually makes use of
600 * EFI_PROPERTIES_TABLE, let's just switch to this
601 * scheme by default for 64-bit.
602 */
603 return efi_map_next_entry_reverse(entry);
604 }
605
606 /* Initial call */
607 if (!entry)
608 return efi.memmap.map;
609
610 entry += efi.memmap.desc_size;
611 if (entry >= efi.memmap.map_end)
612 return NULL;
613
614 return entry;
615 }
616
should_map_region(efi_memory_desc_t * md)617 static bool should_map_region(efi_memory_desc_t *md)
618 {
619 /*
620 * Runtime regions always require runtime mappings (obviously).
621 */
622 if (md->attribute & EFI_MEMORY_RUNTIME)
623 return true;
624
625 /*
626 * 32-bit EFI doesn't suffer from the bug that requires us to
627 * reserve boot services regions, and mixed mode support
628 * doesn't exist for 32-bit kernels.
629 */
630 if (IS_ENABLED(CONFIG_X86_32))
631 return false;
632
633 /*
634 * EFI specific purpose memory may be reserved by default
635 * depending on kernel config and boot options.
636 */
637 if (md->type == EFI_CONVENTIONAL_MEMORY &&
638 efi_soft_reserve_enabled() &&
639 (md->attribute & EFI_MEMORY_SP))
640 return false;
641
642 /*
643 * Map all of RAM so that we can access arguments in the 1:1
644 * mapping when making EFI runtime calls.
645 */
646 if (efi_is_mixed()) {
647 if (md->type == EFI_CONVENTIONAL_MEMORY ||
648 md->type == EFI_LOADER_DATA ||
649 md->type == EFI_LOADER_CODE)
650 return true;
651 }
652
653 /*
654 * Map boot services regions as a workaround for buggy
655 * firmware that accesses them even when they shouldn't.
656 *
657 * See efi_{reserve,free}_boot_services().
658 */
659 if (md->type == EFI_BOOT_SERVICES_CODE ||
660 md->type == EFI_BOOT_SERVICES_DATA)
661 return true;
662
663 return false;
664 }
665
666 /*
667 * Map the efi memory ranges of the runtime services and update new_mmap with
668 * virtual addresses.
669 */
efi_map_regions(int * count,int * pg_shift)670 static void * __init efi_map_regions(int *count, int *pg_shift)
671 {
672 void *p, *new_memmap = NULL;
673 unsigned long left = 0;
674 unsigned long desc_size;
675 efi_memory_desc_t *md;
676
677 desc_size = efi.memmap.desc_size;
678
679 p = NULL;
680 while ((p = efi_map_next_entry(p))) {
681 md = p;
682
683 if (!should_map_region(md))
684 continue;
685
686 efi_map_region(md);
687
688 if (left < desc_size) {
689 new_memmap = realloc_pages(new_memmap, *pg_shift);
690 if (!new_memmap)
691 return NULL;
692
693 left += PAGE_SIZE << *pg_shift;
694 (*pg_shift)++;
695 }
696
697 memcpy(new_memmap + (*count * desc_size), md, desc_size);
698
699 left -= desc_size;
700 (*count)++;
701 }
702
703 return new_memmap;
704 }
705
kexec_enter_virtual_mode(void)706 static void __init kexec_enter_virtual_mode(void)
707 {
708 #ifdef CONFIG_KEXEC_CORE
709 efi_memory_desc_t *md;
710 unsigned int num_pages;
711
712 /*
713 * We don't do virtual mode, since we don't do runtime services, on
714 * non-native EFI.
715 */
716 if (efi_is_mixed()) {
717 efi_memmap_unmap();
718 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
719 return;
720 }
721
722 if (efi_alloc_page_tables()) {
723 pr_err("Failed to allocate EFI page tables\n");
724 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
725 return;
726 }
727
728 /*
729 * Map efi regions which were passed via setup_data. The virt_addr is a
730 * fixed addr which was used in first kernel of a kexec boot.
731 */
732 for_each_efi_memory_desc(md)
733 efi_map_region_fixed(md); /* FIXME: add error handling */
734
735 /*
736 * Unregister the early EFI memmap from efi_init() and install
737 * the new EFI memory map.
738 */
739 efi_memmap_unmap();
740
741 if (efi_memmap_init_late(efi.memmap.phys_map,
742 efi.memmap.desc_size * efi.memmap.nr_map)) {
743 pr_err("Failed to remap late EFI memory map\n");
744 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
745 return;
746 }
747
748 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
749 num_pages >>= PAGE_SHIFT;
750
751 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
752 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
753 return;
754 }
755
756 efi_sync_low_kernel_mappings();
757 efi_native_runtime_setup();
758 #endif
759 }
760
761 /*
762 * This function will switch the EFI runtime services to virtual mode.
763 * Essentially, we look through the EFI memmap and map every region that
764 * has the runtime attribute bit set in its memory descriptor into the
765 * efi_pgd page table.
766 *
767 * The new method does a pagetable switch in a preemption-safe manner
768 * so that we're in a different address space when calling a runtime
769 * function. For function arguments passing we do copy the PUDs of the
770 * kernel page table into efi_pgd prior to each call.
771 *
772 * Specially for kexec boot, efi runtime maps in previous kernel should
773 * be passed in via setup_data. In that case runtime ranges will be mapped
774 * to the same virtual addresses as the first kernel, see
775 * kexec_enter_virtual_mode().
776 */
__efi_enter_virtual_mode(void)777 static void __init __efi_enter_virtual_mode(void)
778 {
779 int count = 0, pg_shift = 0;
780 void *new_memmap = NULL;
781 efi_status_t status;
782 unsigned long pa;
783
784 if (efi_alloc_page_tables()) {
785 pr_err("Failed to allocate EFI page tables\n");
786 goto err;
787 }
788
789 efi_merge_regions();
790 new_memmap = efi_map_regions(&count, &pg_shift);
791 if (!new_memmap) {
792 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
793 goto err;
794 }
795
796 pa = __pa(new_memmap);
797
798 /*
799 * Unregister the early EFI memmap from efi_init() and install
800 * the new EFI memory map that we are about to pass to the
801 * firmware via SetVirtualAddressMap().
802 */
803 efi_memmap_unmap();
804
805 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
806 pr_err("Failed to remap late EFI memory map\n");
807 goto err;
808 }
809
810 if (efi_enabled(EFI_DBG)) {
811 pr_info("EFI runtime memory map:\n");
812 efi_print_memmap();
813 }
814
815 if (efi_setup_page_tables(pa, 1 << pg_shift))
816 goto err;
817
818 efi_sync_low_kernel_mappings();
819
820 status = efi_set_virtual_address_map(efi.memmap.desc_size * count,
821 efi.memmap.desc_size,
822 efi.memmap.desc_version,
823 (efi_memory_desc_t *)pa,
824 efi_systab_phys);
825 if (status != EFI_SUCCESS) {
826 pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n",
827 status);
828 goto err;
829 }
830
831 efi_check_for_embedded_firmwares();
832 efi_free_boot_services();
833
834 if (!efi_is_mixed())
835 efi_native_runtime_setup();
836 else
837 efi_thunk_runtime_setup();
838
839 /*
840 * Apply more restrictive page table mapping attributes now that
841 * SVAM() has been called and the firmware has performed all
842 * necessary relocation fixups for the new virtual addresses.
843 */
844 efi_runtime_update_mappings();
845
846 /* clean DUMMY object */
847 efi_delete_dummy_variable();
848 return;
849
850 err:
851 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
852 }
853
efi_enter_virtual_mode(void)854 void __init efi_enter_virtual_mode(void)
855 {
856 if (efi_enabled(EFI_PARAVIRT))
857 return;
858
859 efi.runtime = (efi_runtime_services_t *)efi_runtime;
860
861 if (efi_setup)
862 kexec_enter_virtual_mode();
863 else
864 __efi_enter_virtual_mode();
865
866 efi_dump_pagetable();
867 }
868
efi_is_table_address(unsigned long phys_addr)869 bool efi_is_table_address(unsigned long phys_addr)
870 {
871 unsigned int i;
872
873 if (phys_addr == EFI_INVALID_TABLE_ADDR)
874 return false;
875
876 for (i = 0; i < ARRAY_SIZE(efi_tables); i++)
877 if (*(efi_tables[i]) == phys_addr)
878 return true;
879
880 return false;
881 }
882
efi_systab_show_arch(char * str)883 char *efi_systab_show_arch(char *str)
884 {
885 if (uga_phys != EFI_INVALID_TABLE_ADDR)
886 str += sprintf(str, "UGA=0x%lx\n", uga_phys);
887 return str;
888 }
889
890 #define EFI_FIELD(var) efi_ ## var
891
892 #define EFI_ATTR_SHOW(name) \
893 static ssize_t name##_show(struct kobject *kobj, \
894 struct kobj_attribute *attr, char *buf) \
895 { \
896 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
897 }
898
899 EFI_ATTR_SHOW(fw_vendor);
900 EFI_ATTR_SHOW(runtime);
901 EFI_ATTR_SHOW(config_table);
902
903 struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
904 struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
905 struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
906
efi_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)907 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
908 {
909 if (attr == &efi_attr_fw_vendor.attr) {
910 if (efi_enabled(EFI_PARAVIRT) ||
911 efi_fw_vendor == EFI_INVALID_TABLE_ADDR)
912 return 0;
913 } else if (attr == &efi_attr_runtime.attr) {
914 if (efi_runtime == EFI_INVALID_TABLE_ADDR)
915 return 0;
916 } else if (attr == &efi_attr_config_table.attr) {
917 if (efi_config_table == EFI_INVALID_TABLE_ADDR)
918 return 0;
919 }
920 return attr->mode;
921 }
922