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 #ifdef CONFIG_EFI_COCO_SECRET
97 &efi.coco_secret,
98 #endif
99 };
100
101 u64 efi_setup; /* efi setup_data physical address */
102
103 static int add_efi_memmap __initdata;
setup_add_efi_memmap(char * arg)104 static int __init setup_add_efi_memmap(char *arg)
105 {
106 add_efi_memmap = 1;
107 return 0;
108 }
109 early_param("add_efi_memmap", setup_add_efi_memmap);
110
efi_find_mirror(void)111 void __init efi_find_mirror(void)
112 {
113 efi_memory_desc_t *md;
114 u64 mirror_size = 0, total_size = 0;
115
116 if (!efi_enabled(EFI_MEMMAP))
117 return;
118
119 for_each_efi_memory_desc(md) {
120 unsigned long long start = md->phys_addr;
121 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
122
123 total_size += size;
124 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
125 memblock_mark_mirror(start, size);
126 mirror_size += size;
127 }
128 }
129 if (mirror_size)
130 pr_info("Memory: %lldM/%lldM mirrored memory\n",
131 mirror_size>>20, total_size>>20);
132 }
133
134 /*
135 * Tell the kernel about the EFI memory map. This might include
136 * more than the max 128 entries that can fit in the passed in e820
137 * legacy (zeropage) memory map, but the kernel's e820 table can hold
138 * E820_MAX_ENTRIES.
139 */
140
do_add_efi_memmap(void)141 static void __init do_add_efi_memmap(void)
142 {
143 efi_memory_desc_t *md;
144
145 if (!efi_enabled(EFI_MEMMAP))
146 return;
147
148 for_each_efi_memory_desc(md) {
149 unsigned long long start = md->phys_addr;
150 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
151 int e820_type;
152
153 switch (md->type) {
154 case EFI_LOADER_CODE:
155 case EFI_LOADER_DATA:
156 case EFI_BOOT_SERVICES_CODE:
157 case EFI_BOOT_SERVICES_DATA:
158 case EFI_CONVENTIONAL_MEMORY:
159 if (efi_soft_reserve_enabled()
160 && (md->attribute & EFI_MEMORY_SP))
161 e820_type = E820_TYPE_SOFT_RESERVED;
162 else if (md->attribute & EFI_MEMORY_WB)
163 e820_type = E820_TYPE_RAM;
164 else
165 e820_type = E820_TYPE_RESERVED;
166 break;
167 case EFI_ACPI_RECLAIM_MEMORY:
168 e820_type = E820_TYPE_ACPI;
169 break;
170 case EFI_ACPI_MEMORY_NVS:
171 e820_type = E820_TYPE_NVS;
172 break;
173 case EFI_UNUSABLE_MEMORY:
174 e820_type = E820_TYPE_UNUSABLE;
175 break;
176 case EFI_PERSISTENT_MEMORY:
177 e820_type = E820_TYPE_PMEM;
178 break;
179 default:
180 /*
181 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
182 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
183 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
184 */
185 e820_type = E820_TYPE_RESERVED;
186 break;
187 }
188
189 e820__range_add(start, size, e820_type);
190 }
191 e820__update_table(e820_table);
192 }
193
194 /*
195 * Given add_efi_memmap defaults to 0 and there there is no alternative
196 * e820 mechanism for soft-reserved memory, import the full EFI memory
197 * map if soft reservations are present and enabled. Otherwise, the
198 * mechanism to disable the kernel's consideration of EFI_MEMORY_SP is
199 * the efi=nosoftreserve option.
200 */
do_efi_soft_reserve(void)201 static bool do_efi_soft_reserve(void)
202 {
203 efi_memory_desc_t *md;
204
205 if (!efi_enabled(EFI_MEMMAP))
206 return false;
207
208 if (!efi_soft_reserve_enabled())
209 return false;
210
211 for_each_efi_memory_desc(md)
212 if (md->type == EFI_CONVENTIONAL_MEMORY &&
213 (md->attribute & EFI_MEMORY_SP))
214 return true;
215 return false;
216 }
217
efi_memblock_x86_reserve_range(void)218 int __init efi_memblock_x86_reserve_range(void)
219 {
220 struct efi_info *e = &boot_params.efi_info;
221 struct efi_memory_map_data data;
222 phys_addr_t pmap;
223 int rv;
224
225 if (efi_enabled(EFI_PARAVIRT))
226 return 0;
227
228 /* Can't handle firmware tables above 4GB on i386 */
229 if (IS_ENABLED(CONFIG_X86_32) && e->efi_memmap_hi > 0) {
230 pr_err("Memory map is above 4GB, disabling EFI.\n");
231 return -EINVAL;
232 }
233 pmap = (phys_addr_t)(e->efi_memmap | ((u64)e->efi_memmap_hi << 32));
234
235 data.phys_map = pmap;
236 data.size = e->efi_memmap_size;
237 data.desc_size = e->efi_memdesc_size;
238 data.desc_version = e->efi_memdesc_version;
239
240 rv = efi_memmap_init_early(&data);
241 if (rv)
242 return rv;
243
244 if (add_efi_memmap || do_efi_soft_reserve())
245 do_add_efi_memmap();
246
247 efi_fake_memmap_early();
248
249 WARN(efi.memmap.desc_version != 1,
250 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
251 efi.memmap.desc_version);
252
253 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
254 set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags);
255
256 return 0;
257 }
258
259 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
260 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
261 #define U64_HIGH_BIT (~(U64_MAX >> 1))
262
efi_memmap_entry_valid(const efi_memory_desc_t * md,int i)263 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
264 {
265 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
266 u64 end_hi = 0;
267 char buf[64];
268
269 if (md->num_pages == 0) {
270 end = 0;
271 } else if (md->num_pages > EFI_PAGES_MAX ||
272 EFI_PAGES_MAX - md->num_pages <
273 (md->phys_addr >> EFI_PAGE_SHIFT)) {
274 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
275 >> OVERFLOW_ADDR_SHIFT;
276
277 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
278 end_hi += 1;
279 } else {
280 return true;
281 }
282
283 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
284
285 if (end_hi) {
286 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
287 i, efi_md_typeattr_format(buf, sizeof(buf), md),
288 md->phys_addr, end_hi, end);
289 } else {
290 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
291 i, efi_md_typeattr_format(buf, sizeof(buf), md),
292 md->phys_addr, end);
293 }
294 return false;
295 }
296
efi_clean_memmap(void)297 static void __init efi_clean_memmap(void)
298 {
299 efi_memory_desc_t *out = efi.memmap.map;
300 const efi_memory_desc_t *in = out;
301 const efi_memory_desc_t *end = efi.memmap.map_end;
302 int i, n_removal;
303
304 for (i = n_removal = 0; in < end; i++) {
305 if (efi_memmap_entry_valid(in, i)) {
306 if (out != in)
307 memcpy(out, in, efi.memmap.desc_size);
308 out = (void *)out + efi.memmap.desc_size;
309 } else {
310 n_removal++;
311 }
312 in = (void *)in + efi.memmap.desc_size;
313 }
314
315 if (n_removal > 0) {
316 struct efi_memory_map_data data = {
317 .phys_map = efi.memmap.phys_map,
318 .desc_version = efi.memmap.desc_version,
319 .desc_size = efi.memmap.desc_size,
320 .size = efi.memmap.desc_size * (efi.memmap.nr_map - n_removal),
321 .flags = 0,
322 };
323
324 pr_warn("Removing %d invalid memory map entries.\n", n_removal);
325 efi_memmap_install(&data);
326 }
327 }
328
efi_print_memmap(void)329 void __init efi_print_memmap(void)
330 {
331 efi_memory_desc_t *md;
332 int i = 0;
333
334 for_each_efi_memory_desc(md) {
335 char buf[64];
336
337 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
338 i++, efi_md_typeattr_format(buf, sizeof(buf), md),
339 md->phys_addr,
340 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
341 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
342 }
343 }
344
efi_systab_init(unsigned long phys)345 static int __init efi_systab_init(unsigned long phys)
346 {
347 int size = efi_enabled(EFI_64BIT) ? sizeof(efi_system_table_64_t)
348 : sizeof(efi_system_table_32_t);
349 const efi_table_hdr_t *hdr;
350 bool over4g = false;
351 void *p;
352 int ret;
353
354 hdr = p = early_memremap_ro(phys, size);
355 if (p == NULL) {
356 pr_err("Couldn't map the system table!\n");
357 return -ENOMEM;
358 }
359
360 ret = efi_systab_check_header(hdr, 1);
361 if (ret) {
362 early_memunmap(p, size);
363 return ret;
364 }
365
366 if (efi_enabled(EFI_64BIT)) {
367 const efi_system_table_64_t *systab64 = p;
368
369 efi_runtime = systab64->runtime;
370 over4g = systab64->runtime > U32_MAX;
371
372 if (efi_setup) {
373 struct efi_setup_data *data;
374
375 data = early_memremap_ro(efi_setup, sizeof(*data));
376 if (!data) {
377 early_memunmap(p, size);
378 return -ENOMEM;
379 }
380
381 efi_fw_vendor = (unsigned long)data->fw_vendor;
382 efi_config_table = (unsigned long)data->tables;
383
384 over4g |= data->fw_vendor > U32_MAX ||
385 data->tables > U32_MAX;
386
387 early_memunmap(data, sizeof(*data));
388 } else {
389 efi_fw_vendor = systab64->fw_vendor;
390 efi_config_table = systab64->tables;
391
392 over4g |= systab64->fw_vendor > U32_MAX ||
393 systab64->tables > U32_MAX;
394 }
395 efi_nr_tables = systab64->nr_tables;
396 } else {
397 const efi_system_table_32_t *systab32 = p;
398
399 efi_fw_vendor = systab32->fw_vendor;
400 efi_runtime = systab32->runtime;
401 efi_config_table = systab32->tables;
402 efi_nr_tables = systab32->nr_tables;
403 }
404
405 efi.runtime_version = hdr->revision;
406
407 efi_systab_report_header(hdr, efi_fw_vendor);
408 early_memunmap(p, size);
409
410 if (IS_ENABLED(CONFIG_X86_32) && over4g) {
411 pr_err("EFI data located above 4GB, disabling EFI.\n");
412 return -EINVAL;
413 }
414
415 return 0;
416 }
417
efi_config_init(const efi_config_table_type_t * arch_tables)418 static int __init efi_config_init(const efi_config_table_type_t *arch_tables)
419 {
420 void *config_tables;
421 int sz, ret;
422
423 if (efi_nr_tables == 0)
424 return 0;
425
426 if (efi_enabled(EFI_64BIT))
427 sz = sizeof(efi_config_table_64_t);
428 else
429 sz = sizeof(efi_config_table_32_t);
430
431 /*
432 * Let's see what config tables the firmware passed to us.
433 */
434 config_tables = early_memremap(efi_config_table, efi_nr_tables * sz);
435 if (config_tables == NULL) {
436 pr_err("Could not map Configuration table!\n");
437 return -ENOMEM;
438 }
439
440 ret = efi_config_parse_tables(config_tables, efi_nr_tables,
441 arch_tables);
442
443 early_memunmap(config_tables, efi_nr_tables * sz);
444 return ret;
445 }
446
efi_init(void)447 void __init efi_init(void)
448 {
449 if (IS_ENABLED(CONFIG_X86_32) &&
450 (boot_params.efi_info.efi_systab_hi ||
451 boot_params.efi_info.efi_memmap_hi)) {
452 pr_info("Table located above 4GB, disabling EFI.\n");
453 return;
454 }
455
456 efi_systab_phys = boot_params.efi_info.efi_systab |
457 ((__u64)boot_params.efi_info.efi_systab_hi << 32);
458
459 if (efi_systab_init(efi_systab_phys))
460 return;
461
462 if (efi_reuse_config(efi_config_table, efi_nr_tables))
463 return;
464
465 if (efi_config_init(arch_tables))
466 return;
467
468 /*
469 * Note: We currently don't support runtime services on an EFI
470 * that doesn't match the kernel 32/64-bit mode.
471 */
472
473 if (!efi_runtime_supported())
474 pr_err("No EFI runtime due to 32/64-bit mismatch with kernel\n");
475
476 if (!efi_runtime_supported() || efi_runtime_disabled()) {
477 efi_memmap_unmap();
478 return;
479 }
480
481 /* Parse the EFI Properties table if it exists */
482 if (prop_phys != EFI_INVALID_TABLE_ADDR) {
483 efi_properties_table_t *tbl;
484
485 tbl = early_memremap_ro(prop_phys, sizeof(*tbl));
486 if (tbl == NULL) {
487 pr_err("Could not map Properties table!\n");
488 } else {
489 if (tbl->memory_protection_attribute &
490 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
491 set_bit(EFI_NX_PE_DATA, &efi.flags);
492
493 early_memunmap(tbl, sizeof(*tbl));
494 }
495 }
496
497 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
498 efi_clean_memmap();
499
500 if (efi_enabled(EFI_DBG))
501 efi_print_memmap();
502 }
503
504 /* Merge contiguous regions of the same type and attribute */
efi_merge_regions(void)505 static void __init efi_merge_regions(void)
506 {
507 efi_memory_desc_t *md, *prev_md = NULL;
508
509 for_each_efi_memory_desc(md) {
510 u64 prev_size;
511
512 if (!prev_md) {
513 prev_md = md;
514 continue;
515 }
516
517 if (prev_md->type != md->type ||
518 prev_md->attribute != md->attribute) {
519 prev_md = md;
520 continue;
521 }
522
523 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
524
525 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
526 prev_md->num_pages += md->num_pages;
527 md->type = EFI_RESERVED_TYPE;
528 md->attribute = 0;
529 continue;
530 }
531 prev_md = md;
532 }
533 }
534
realloc_pages(void * old_memmap,int old_shift)535 static void *realloc_pages(void *old_memmap, int old_shift)
536 {
537 void *ret;
538
539 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
540 if (!ret)
541 goto out;
542
543 /*
544 * A first-time allocation doesn't have anything to copy.
545 */
546 if (!old_memmap)
547 return ret;
548
549 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
550
551 out:
552 free_pages((unsigned long)old_memmap, old_shift);
553 return ret;
554 }
555
556 /*
557 * Iterate the EFI memory map in reverse order because the regions
558 * will be mapped top-down. The end result is the same as if we had
559 * mapped things forward, but doesn't require us to change the
560 * existing implementation of efi_map_region().
561 */
efi_map_next_entry_reverse(void * entry)562 static inline void *efi_map_next_entry_reverse(void *entry)
563 {
564 /* Initial call */
565 if (!entry)
566 return efi.memmap.map_end - efi.memmap.desc_size;
567
568 entry -= efi.memmap.desc_size;
569 if (entry < efi.memmap.map)
570 return NULL;
571
572 return entry;
573 }
574
575 /*
576 * efi_map_next_entry - Return the next EFI memory map descriptor
577 * @entry: Previous EFI memory map descriptor
578 *
579 * This is a helper function to iterate over the EFI memory map, which
580 * we do in different orders depending on the current configuration.
581 *
582 * To begin traversing the memory map @entry must be %NULL.
583 *
584 * Returns %NULL when we reach the end of the memory map.
585 */
efi_map_next_entry(void * entry)586 static void *efi_map_next_entry(void *entry)
587 {
588 if (efi_enabled(EFI_64BIT)) {
589 /*
590 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
591 * config table feature requires us to map all entries
592 * in the same order as they appear in the EFI memory
593 * map. That is to say, entry N must have a lower
594 * virtual address than entry N+1. This is because the
595 * firmware toolchain leaves relative references in
596 * the code/data sections, which are split and become
597 * separate EFI memory regions. Mapping things
598 * out-of-order leads to the firmware accessing
599 * unmapped addresses.
600 *
601 * Since we need to map things this way whether or not
602 * the kernel actually makes use of
603 * EFI_PROPERTIES_TABLE, let's just switch to this
604 * scheme by default for 64-bit.
605 */
606 return efi_map_next_entry_reverse(entry);
607 }
608
609 /* Initial call */
610 if (!entry)
611 return efi.memmap.map;
612
613 entry += efi.memmap.desc_size;
614 if (entry >= efi.memmap.map_end)
615 return NULL;
616
617 return entry;
618 }
619
should_map_region(efi_memory_desc_t * md)620 static bool should_map_region(efi_memory_desc_t *md)
621 {
622 /*
623 * Runtime regions always require runtime mappings (obviously).
624 */
625 if (md->attribute & EFI_MEMORY_RUNTIME)
626 return true;
627
628 /*
629 * 32-bit EFI doesn't suffer from the bug that requires us to
630 * reserve boot services regions, and mixed mode support
631 * doesn't exist for 32-bit kernels.
632 */
633 if (IS_ENABLED(CONFIG_X86_32))
634 return false;
635
636 /*
637 * EFI specific purpose memory may be reserved by default
638 * depending on kernel config and boot options.
639 */
640 if (md->type == EFI_CONVENTIONAL_MEMORY &&
641 efi_soft_reserve_enabled() &&
642 (md->attribute & EFI_MEMORY_SP))
643 return false;
644
645 /*
646 * Map all of RAM so that we can access arguments in the 1:1
647 * mapping when making EFI runtime calls.
648 */
649 if (efi_is_mixed()) {
650 if (md->type == EFI_CONVENTIONAL_MEMORY ||
651 md->type == EFI_LOADER_DATA ||
652 md->type == EFI_LOADER_CODE)
653 return true;
654 }
655
656 /*
657 * Map boot services regions as a workaround for buggy
658 * firmware that accesses them even when they shouldn't.
659 *
660 * See efi_{reserve,free}_boot_services().
661 */
662 if (md->type == EFI_BOOT_SERVICES_CODE ||
663 md->type == EFI_BOOT_SERVICES_DATA)
664 return true;
665
666 return false;
667 }
668
669 /*
670 * Map the efi memory ranges of the runtime services and update new_mmap with
671 * virtual addresses.
672 */
efi_map_regions(int * count,int * pg_shift)673 static void * __init efi_map_regions(int *count, int *pg_shift)
674 {
675 void *p, *new_memmap = NULL;
676 unsigned long left = 0;
677 unsigned long desc_size;
678 efi_memory_desc_t *md;
679
680 desc_size = efi.memmap.desc_size;
681
682 p = NULL;
683 while ((p = efi_map_next_entry(p))) {
684 md = p;
685
686 if (!should_map_region(md))
687 continue;
688
689 efi_map_region(md);
690
691 if (left < desc_size) {
692 new_memmap = realloc_pages(new_memmap, *pg_shift);
693 if (!new_memmap)
694 return NULL;
695
696 left += PAGE_SIZE << *pg_shift;
697 (*pg_shift)++;
698 }
699
700 memcpy(new_memmap + (*count * desc_size), md, desc_size);
701
702 left -= desc_size;
703 (*count)++;
704 }
705
706 return new_memmap;
707 }
708
kexec_enter_virtual_mode(void)709 static void __init kexec_enter_virtual_mode(void)
710 {
711 #ifdef CONFIG_KEXEC_CORE
712 efi_memory_desc_t *md;
713 unsigned int num_pages;
714
715 /*
716 * We don't do virtual mode, since we don't do runtime services, on
717 * non-native EFI.
718 */
719 if (efi_is_mixed()) {
720 efi_memmap_unmap();
721 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
722 return;
723 }
724
725 if (efi_alloc_page_tables()) {
726 pr_err("Failed to allocate EFI page tables\n");
727 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
728 return;
729 }
730
731 /*
732 * Map efi regions which were passed via setup_data. The virt_addr is a
733 * fixed addr which was used in first kernel of a kexec boot.
734 */
735 for_each_efi_memory_desc(md)
736 efi_map_region_fixed(md); /* FIXME: add error handling */
737
738 /*
739 * Unregister the early EFI memmap from efi_init() and install
740 * the new EFI memory map.
741 */
742 efi_memmap_unmap();
743
744 if (efi_memmap_init_late(efi.memmap.phys_map,
745 efi.memmap.desc_size * efi.memmap.nr_map)) {
746 pr_err("Failed to remap late EFI memory map\n");
747 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
748 return;
749 }
750
751 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
752 num_pages >>= PAGE_SHIFT;
753
754 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
755 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
756 return;
757 }
758
759 efi_sync_low_kernel_mappings();
760 efi_native_runtime_setup();
761 #endif
762 }
763
764 /*
765 * This function will switch the EFI runtime services to virtual mode.
766 * Essentially, we look through the EFI memmap and map every region that
767 * has the runtime attribute bit set in its memory descriptor into the
768 * efi_pgd page table.
769 *
770 * The new method does a pagetable switch in a preemption-safe manner
771 * so that we're in a different address space when calling a runtime
772 * function. For function arguments passing we do copy the PUDs of the
773 * kernel page table into efi_pgd prior to each call.
774 *
775 * Specially for kexec boot, efi runtime maps in previous kernel should
776 * be passed in via setup_data. In that case runtime ranges will be mapped
777 * to the same virtual addresses as the first kernel, see
778 * kexec_enter_virtual_mode().
779 */
__efi_enter_virtual_mode(void)780 static void __init __efi_enter_virtual_mode(void)
781 {
782 int count = 0, pg_shift = 0;
783 void *new_memmap = NULL;
784 efi_status_t status;
785 unsigned long pa;
786
787 if (efi_alloc_page_tables()) {
788 pr_err("Failed to allocate EFI page tables\n");
789 goto err;
790 }
791
792 efi_merge_regions();
793 new_memmap = efi_map_regions(&count, &pg_shift);
794 if (!new_memmap) {
795 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
796 goto err;
797 }
798
799 pa = __pa(new_memmap);
800
801 /*
802 * Unregister the early EFI memmap from efi_init() and install
803 * the new EFI memory map that we are about to pass to the
804 * firmware via SetVirtualAddressMap().
805 */
806 efi_memmap_unmap();
807
808 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
809 pr_err("Failed to remap late EFI memory map\n");
810 goto err;
811 }
812
813 if (efi_enabled(EFI_DBG)) {
814 pr_info("EFI runtime memory map:\n");
815 efi_print_memmap();
816 }
817
818 if (efi_setup_page_tables(pa, 1 << pg_shift))
819 goto err;
820
821 efi_sync_low_kernel_mappings();
822
823 status = efi_set_virtual_address_map(efi.memmap.desc_size * count,
824 efi.memmap.desc_size,
825 efi.memmap.desc_version,
826 (efi_memory_desc_t *)pa,
827 efi_systab_phys);
828 if (status != EFI_SUCCESS) {
829 pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n",
830 status);
831 goto err;
832 }
833
834 efi_check_for_embedded_firmwares();
835 efi_free_boot_services();
836
837 if (!efi_is_mixed())
838 efi_native_runtime_setup();
839 else
840 efi_thunk_runtime_setup();
841
842 /*
843 * Apply more restrictive page table mapping attributes now that
844 * SVAM() has been called and the firmware has performed all
845 * necessary relocation fixups for the new virtual addresses.
846 */
847 efi_runtime_update_mappings();
848
849 /* clean DUMMY object */
850 efi_delete_dummy_variable();
851 return;
852
853 err:
854 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
855 }
856
efi_enter_virtual_mode(void)857 void __init efi_enter_virtual_mode(void)
858 {
859 if (efi_enabled(EFI_PARAVIRT))
860 return;
861
862 efi.runtime = (efi_runtime_services_t *)efi_runtime;
863
864 if (efi_setup)
865 kexec_enter_virtual_mode();
866 else
867 __efi_enter_virtual_mode();
868
869 efi_dump_pagetable();
870 }
871
efi_is_table_address(unsigned long phys_addr)872 bool efi_is_table_address(unsigned long phys_addr)
873 {
874 unsigned int i;
875
876 if (phys_addr == EFI_INVALID_TABLE_ADDR)
877 return false;
878
879 for (i = 0; i < ARRAY_SIZE(efi_tables); i++)
880 if (*(efi_tables[i]) == phys_addr)
881 return true;
882
883 return false;
884 }
885
efi_systab_show_arch(char * str)886 char *efi_systab_show_arch(char *str)
887 {
888 if (uga_phys != EFI_INVALID_TABLE_ADDR)
889 str += sprintf(str, "UGA=0x%lx\n", uga_phys);
890 return str;
891 }
892
893 #define EFI_FIELD(var) efi_ ## var
894
895 #define EFI_ATTR_SHOW(name) \
896 static ssize_t name##_show(struct kobject *kobj, \
897 struct kobj_attribute *attr, char *buf) \
898 { \
899 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
900 }
901
902 EFI_ATTR_SHOW(fw_vendor);
903 EFI_ATTR_SHOW(runtime);
904 EFI_ATTR_SHOW(config_table);
905
906 struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
907 struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
908 struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
909
efi_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)910 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
911 {
912 if (attr == &efi_attr_fw_vendor.attr) {
913 if (efi_enabled(EFI_PARAVIRT) ||
914 efi_fw_vendor == EFI_INVALID_TABLE_ADDR)
915 return 0;
916 } else if (attr == &efi_attr_runtime.attr) {
917 if (efi_runtime == EFI_INVALID_TABLE_ADDR)
918 return 0;
919 } else if (attr == &efi_attr_config_table.attr) {
920 if (efi_config_table == EFI_INVALID_TABLE_ADDR)
921 return 0;
922 }
923 return attr->mode;
924 }
925