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 #ifdef CONFIG_UNACCEPTED_MEMORY
100 &efi.unaccepted,
101 #endif
102 };
103
104 u64 efi_setup; /* efi setup_data physical address */
105
106 static int add_efi_memmap __initdata;
107 static int __init setup_add_efi_memmap(char *arg)
108 {
109 add_efi_memmap = 1;
110 return 0;
111 }
112 early_param("add_efi_memmap", setup_add_efi_memmap);
113
114 /*
115 * Tell the kernel about the EFI memory map. This might include
116 * more than the max 128 entries that can fit in the passed in e820
117 * legacy (zeropage) memory map, but the kernel's e820 table can hold
118 * E820_MAX_ENTRIES.
119 */
120
121 static void __init do_add_efi_memmap(void)
122 {
123 efi_memory_desc_t *md;
124
125 if (!efi_enabled(EFI_MEMMAP))
126 return;
127
128 for_each_efi_memory_desc(md) {
129 unsigned long long start = md->phys_addr;
130 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
131 int e820_type;
132
133 switch (md->type) {
134 case EFI_LOADER_CODE:
135 case EFI_LOADER_DATA:
136 case EFI_BOOT_SERVICES_CODE:
137 case EFI_BOOT_SERVICES_DATA:
138 case EFI_CONVENTIONAL_MEMORY:
139 if (efi_soft_reserve_enabled()
140 && (md->attribute & EFI_MEMORY_SP))
141 e820_type = E820_TYPE_SOFT_RESERVED;
142 else if (md->attribute & EFI_MEMORY_WB)
143 e820_type = E820_TYPE_RAM;
144 else
145 e820_type = E820_TYPE_RESERVED;
146 break;
147 case EFI_ACPI_RECLAIM_MEMORY:
148 e820_type = E820_TYPE_ACPI;
149 break;
150 case EFI_ACPI_MEMORY_NVS:
151 e820_type = E820_TYPE_NVS;
152 break;
153 case EFI_UNUSABLE_MEMORY:
154 e820_type = E820_TYPE_UNUSABLE;
155 break;
156 case EFI_PERSISTENT_MEMORY:
157 e820_type = E820_TYPE_PMEM;
158 break;
159 default:
160 /*
161 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
162 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
163 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
164 */
165 e820_type = E820_TYPE_RESERVED;
166 break;
167 }
168
169 e820__range_add(start, size, e820_type);
170 }
171 e820__update_table(e820_table);
172 }
173
174 /*
175 * Given add_efi_memmap defaults to 0 and there is no alternative
176 * e820 mechanism for soft-reserved memory, import the full EFI memory
177 * map if soft reservations are present and enabled. Otherwise, the
178 * mechanism to disable the kernel's consideration of EFI_MEMORY_SP is
179 * the efi=nosoftreserve option.
180 */
181 static bool do_efi_soft_reserve(void)
182 {
183 efi_memory_desc_t *md;
184
185 if (!efi_enabled(EFI_MEMMAP))
186 return false;
187
188 if (!efi_soft_reserve_enabled())
189 return false;
190
191 for_each_efi_memory_desc(md)
192 if (md->type == EFI_CONVENTIONAL_MEMORY &&
193 (md->attribute & EFI_MEMORY_SP))
194 return true;
195 return false;
196 }
197
198 int __init efi_memblock_x86_reserve_range(void)
199 {
200 struct efi_info *e = &boot_params.efi_info;
201 struct efi_memory_map_data data;
202 phys_addr_t pmap;
203 int rv;
204
205 if (efi_enabled(EFI_PARAVIRT))
206 return 0;
207
208 /* Can't handle firmware tables above 4GB on i386 */
209 if (IS_ENABLED(CONFIG_X86_32) && e->efi_memmap_hi > 0) {
210 pr_err("Memory map is above 4GB, disabling EFI.\n");
211 return -EINVAL;
212 }
213 pmap = (phys_addr_t)(e->efi_memmap | ((u64)e->efi_memmap_hi << 32));
214
215 data.phys_map = pmap;
216 data.size = e->efi_memmap_size;
217 data.desc_size = e->efi_memdesc_size;
218 data.desc_version = e->efi_memdesc_version;
219
220 if (!efi_enabled(EFI_PARAVIRT)) {
221 rv = efi_memmap_init_early(&data);
222 if (rv)
223 return rv;
224 }
225
226 if (add_efi_memmap || do_efi_soft_reserve())
227 do_add_efi_memmap();
228
229 WARN(efi.memmap.desc_version != 1,
230 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
231 efi.memmap.desc_version);
232
233 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
234 set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags);
235
236 return 0;
237 }
238
239 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
240 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
241 #define U64_HIGH_BIT (~(U64_MAX >> 1))
242
243 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
244 {
245 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
246 u64 end_hi = 0;
247 char buf[64];
248
249 if (md->num_pages == 0) {
250 end = 0;
251 } else if (md->num_pages > EFI_PAGES_MAX ||
252 EFI_PAGES_MAX - md->num_pages <
253 (md->phys_addr >> EFI_PAGE_SHIFT)) {
254 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
255 >> OVERFLOW_ADDR_SHIFT;
256
257 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
258 end_hi += 1;
259 } else {
260 return true;
261 }
262
263 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
264
265 if (end_hi) {
266 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
267 i, efi_md_typeattr_format(buf, sizeof(buf), md),
268 md->phys_addr, end_hi, end);
269 } else {
270 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
271 i, efi_md_typeattr_format(buf, sizeof(buf), md),
272 md->phys_addr, end);
273 }
274 return false;
275 }
276
277 static void __init efi_clean_memmap(void)
278 {
279 efi_memory_desc_t *out = efi.memmap.map;
280 const efi_memory_desc_t *in = out;
281 const efi_memory_desc_t *end = efi.memmap.map_end;
282 int i, n_removal;
283
284 for (i = n_removal = 0; in < end; i++) {
285 if (efi_memmap_entry_valid(in, i)) {
286 if (out != in)
287 memcpy(out, in, efi.memmap.desc_size);
288 out = (void *)out + efi.memmap.desc_size;
289 } else {
290 n_removal++;
291 }
292 in = (void *)in + efi.memmap.desc_size;
293 }
294
295 if (n_removal > 0) {
296 struct efi_memory_map_data data = {
297 .phys_map = efi.memmap.phys_map,
298 .desc_version = efi.memmap.desc_version,
299 .desc_size = efi.memmap.desc_size,
300 .size = efi.memmap.desc_size * (efi.memmap.nr_map - n_removal),
301 .flags = 0,
302 };
303
304 pr_warn("Removing %d invalid memory map entries.\n", n_removal);
305 efi_memmap_install(&data);
306 }
307 }
308
309 /*
310 * Firmware can use EfiMemoryMappedIO to request that MMIO regions be
311 * mapped by the OS so they can be accessed by EFI runtime services, but
312 * should have no other significance to the OS (UEFI r2.10, sec 7.2).
313 * However, most bootloaders and EFI stubs convert EfiMemoryMappedIO
314 * regions to E820_TYPE_RESERVED entries, which prevent Linux from
315 * allocating space from them (see remove_e820_regions()).
316 *
317 * Some platforms use EfiMemoryMappedIO entries for PCI MMCONFIG space and
318 * PCI host bridge windows, which means Linux can't allocate BAR space for
319 * hot-added devices.
320 *
321 * Remove large EfiMemoryMappedIO regions from the E820 map to avoid this
322 * problem.
323 *
324 * Retain small EfiMemoryMappedIO regions because on some platforms, these
325 * describe non-window space that's included in host bridge _CRS. If we
326 * assign that space to PCI devices, they don't work.
327 */
328 static void __init efi_remove_e820_mmio(void)
329 {
330 efi_memory_desc_t *md;
331 u64 size, start, end;
332 int i = 0;
333
334 for_each_efi_memory_desc(md) {
335 if (md->type == EFI_MEMORY_MAPPED_IO) {
336 size = md->num_pages << EFI_PAGE_SHIFT;
337 start = md->phys_addr;
338 end = start + size - 1;
339 if (size >= 256*1024) {
340 pr_info("Remove mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluMB) from e820 map\n",
341 i, start, end, size >> 20);
342 e820__range_remove(start, size,
343 E820_TYPE_RESERVED, 1);
344 } else {
345 pr_info("Not removing mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluKB) from e820 map\n",
346 i, start, end, size >> 10);
347 }
348 }
349 i++;
350 }
351 }
352
353 void __init efi_print_memmap(void)
354 {
355 efi_memory_desc_t *md;
356 int i = 0;
357
358 for_each_efi_memory_desc(md) {
359 char buf[64];
360
361 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
362 i++, efi_md_typeattr_format(buf, sizeof(buf), md),
363 md->phys_addr,
364 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
365 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
366 }
367 }
368
369 static int __init efi_systab_init(unsigned long phys)
370 {
371 int size = efi_enabled(EFI_64BIT) ? sizeof(efi_system_table_64_t)
372 : sizeof(efi_system_table_32_t);
373 const efi_table_hdr_t *hdr;
374 bool over4g = false;
375 void *p;
376 int ret;
377
378 hdr = p = early_memremap_ro(phys, size);
379 if (p == NULL) {
380 pr_err("Couldn't map the system table!\n");
381 return -ENOMEM;
382 }
383
384 ret = efi_systab_check_header(hdr);
385 if (ret) {
386 early_memunmap(p, size);
387 return ret;
388 }
389
390 if (efi_enabled(EFI_64BIT)) {
391 const efi_system_table_64_t *systab64 = p;
392
393 efi_runtime = systab64->runtime;
394 over4g = systab64->runtime > U32_MAX;
395
396 if (efi_setup) {
397 struct efi_setup_data *data;
398
399 data = early_memremap_ro(efi_setup, sizeof(*data));
400 if (!data) {
401 early_memunmap(p, size);
402 return -ENOMEM;
403 }
404
405 efi_fw_vendor = (unsigned long)data->fw_vendor;
406 efi_config_table = (unsigned long)data->tables;
407
408 over4g |= data->fw_vendor > U32_MAX ||
409 data->tables > U32_MAX;
410
411 early_memunmap(data, sizeof(*data));
412 } else {
413 efi_fw_vendor = systab64->fw_vendor;
414 efi_config_table = systab64->tables;
415
416 over4g |= systab64->fw_vendor > U32_MAX ||
417 systab64->tables > U32_MAX;
418 }
419 efi_nr_tables = systab64->nr_tables;
420 } else {
421 const efi_system_table_32_t *systab32 = p;
422
423 efi_fw_vendor = systab32->fw_vendor;
424 efi_runtime = systab32->runtime;
425 efi_config_table = systab32->tables;
426 efi_nr_tables = systab32->nr_tables;
427 }
428
429 efi.runtime_version = hdr->revision;
430
431 efi_systab_report_header(hdr, efi_fw_vendor);
432 early_memunmap(p, size);
433
434 if (IS_ENABLED(CONFIG_X86_32) && over4g) {
435 pr_err("EFI data located above 4GB, disabling EFI.\n");
436 return -EINVAL;
437 }
438
439 return 0;
440 }
441
442 static int __init efi_config_init(const efi_config_table_type_t *arch_tables)
443 {
444 void *config_tables;
445 int sz, ret;
446
447 if (efi_nr_tables == 0)
448 return 0;
449
450 if (efi_enabled(EFI_64BIT))
451 sz = sizeof(efi_config_table_64_t);
452 else
453 sz = sizeof(efi_config_table_32_t);
454
455 /*
456 * Let's see what config tables the firmware passed to us.
457 */
458 config_tables = early_memremap(efi_config_table, efi_nr_tables * sz);
459 if (config_tables == NULL) {
460 pr_err("Could not map Configuration table!\n");
461 return -ENOMEM;
462 }
463
464 ret = efi_config_parse_tables(config_tables, efi_nr_tables,
465 arch_tables);
466
467 early_memunmap(config_tables, efi_nr_tables * sz);
468 return ret;
469 }
470
471 void __init efi_init(void)
472 {
473 if (IS_ENABLED(CONFIG_X86_32) &&
474 (boot_params.efi_info.efi_systab_hi ||
475 boot_params.efi_info.efi_memmap_hi)) {
476 pr_info("Table located above 4GB, disabling EFI.\n");
477 return;
478 }
479
480 efi_systab_phys = boot_params.efi_info.efi_systab |
481 ((__u64)boot_params.efi_info.efi_systab_hi << 32);
482
483 if (efi_systab_init(efi_systab_phys))
484 return;
485
486 if (efi_reuse_config(efi_config_table, efi_nr_tables))
487 return;
488
489 if (efi_config_init(arch_tables))
490 return;
491
492 /*
493 * Note: We currently don't support runtime services on an EFI
494 * that doesn't match the kernel 32/64-bit mode.
495 */
496
497 if (!efi_runtime_supported())
498 pr_err("No EFI runtime due to 32/64-bit mismatch with kernel\n");
499
500 if (!efi_runtime_supported() || efi_runtime_disabled()) {
501 efi_memmap_unmap();
502 return;
503 }
504
505 /* Parse the EFI Properties table if it exists */
506 if (prop_phys != EFI_INVALID_TABLE_ADDR) {
507 efi_properties_table_t *tbl;
508
509 tbl = early_memremap_ro(prop_phys, sizeof(*tbl));
510 if (tbl == NULL) {
511 pr_err("Could not map Properties table!\n");
512 } else {
513 if (tbl->memory_protection_attribute &
514 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
515 set_bit(EFI_NX_PE_DATA, &efi.flags);
516
517 early_memunmap(tbl, sizeof(*tbl));
518 }
519 }
520
521 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
522 efi_clean_memmap();
523
524 efi_remove_e820_mmio();
525
526 if (efi_enabled(EFI_DBG))
527 efi_print_memmap();
528 }
529
530 /* Merge contiguous regions of the same type and attribute */
531 static void __init efi_merge_regions(void)
532 {
533 efi_memory_desc_t *md, *prev_md = NULL;
534
535 for_each_efi_memory_desc(md) {
536 u64 prev_size;
537
538 if (!prev_md) {
539 prev_md = md;
540 continue;
541 }
542
543 if (prev_md->type != md->type ||
544 prev_md->attribute != md->attribute) {
545 prev_md = md;
546 continue;
547 }
548
549 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
550
551 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
552 prev_md->num_pages += md->num_pages;
553 md->type = EFI_RESERVED_TYPE;
554 md->attribute = 0;
555 continue;
556 }
557 prev_md = md;
558 }
559 }
560
561 static void *realloc_pages(void *old_memmap, int old_shift)
562 {
563 void *ret;
564
565 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
566 if (!ret)
567 goto out;
568
569 /*
570 * A first-time allocation doesn't have anything to copy.
571 */
572 if (!old_memmap)
573 return ret;
574
575 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
576
577 out:
578 free_pages((unsigned long)old_memmap, old_shift);
579 return ret;
580 }
581
582 /*
583 * Iterate the EFI memory map in reverse order because the regions
584 * will be mapped top-down. The end result is the same as if we had
585 * mapped things forward, but doesn't require us to change the
586 * existing implementation of efi_map_region().
587 */
588 static inline void *efi_map_next_entry_reverse(void *entry)
589 {
590 /* Initial call */
591 if (!entry)
592 return efi.memmap.map_end - efi.memmap.desc_size;
593
594 entry -= efi.memmap.desc_size;
595 if (entry < efi.memmap.map)
596 return NULL;
597
598 return entry;
599 }
600
601 /*
602 * efi_map_next_entry - Return the next EFI memory map descriptor
603 * @entry: Previous EFI memory map descriptor
604 *
605 * This is a helper function to iterate over the EFI memory map, which
606 * we do in different orders depending on the current configuration.
607 *
608 * To begin traversing the memory map @entry must be %NULL.
609 *
610 * Returns %NULL when we reach the end of the memory map.
611 */
612 static void *efi_map_next_entry(void *entry)
613 {
614 if (efi_enabled(EFI_64BIT)) {
615 /*
616 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
617 * config table feature requires us to map all entries
618 * in the same order as they appear in the EFI memory
619 * map. That is to say, entry N must have a lower
620 * virtual address than entry N+1. This is because the
621 * firmware toolchain leaves relative references in
622 * the code/data sections, which are split and become
623 * separate EFI memory regions. Mapping things
624 * out-of-order leads to the firmware accessing
625 * unmapped addresses.
626 *
627 * Since we need to map things this way whether or not
628 * the kernel actually makes use of
629 * EFI_PROPERTIES_TABLE, let's just switch to this
630 * scheme by default for 64-bit.
631 */
632 return efi_map_next_entry_reverse(entry);
633 }
634
635 /* Initial call */
636 if (!entry)
637 return efi.memmap.map;
638
639 entry += efi.memmap.desc_size;
640 if (entry >= efi.memmap.map_end)
641 return NULL;
642
643 return entry;
644 }
645
646 static bool should_map_region(efi_memory_desc_t *md)
647 {
648 /*
649 * Runtime regions always require runtime mappings (obviously).
650 */
651 if (md->attribute & EFI_MEMORY_RUNTIME)
652 return true;
653
654 /*
655 * 32-bit EFI doesn't suffer from the bug that requires us to
656 * reserve boot services regions, and mixed mode support
657 * doesn't exist for 32-bit kernels.
658 */
659 if (IS_ENABLED(CONFIG_X86_32))
660 return false;
661
662 /*
663 * EFI specific purpose memory may be reserved by default
664 * depending on kernel config and boot options.
665 */
666 if (md->type == EFI_CONVENTIONAL_MEMORY &&
667 efi_soft_reserve_enabled() &&
668 (md->attribute & EFI_MEMORY_SP))
669 return false;
670
671 /*
672 * Map all of RAM so that we can access arguments in the 1:1
673 * mapping when making EFI runtime calls.
674 */
675 if (efi_is_mixed()) {
676 if (md->type == EFI_CONVENTIONAL_MEMORY ||
677 md->type == EFI_LOADER_DATA ||
678 md->type == EFI_LOADER_CODE)
679 return true;
680 }
681
682 /*
683 * Map boot services regions as a workaround for buggy
684 * firmware that accesses them even when they shouldn't.
685 *
686 * See efi_{reserve,free}_boot_services().
687 */
688 if (md->type == EFI_BOOT_SERVICES_CODE ||
689 md->type == EFI_BOOT_SERVICES_DATA)
690 return true;
691
692 return false;
693 }
694
695 /*
696 * Map the efi memory ranges of the runtime services and update new_mmap with
697 * virtual addresses.
698 */
699 static void * __init efi_map_regions(int *count, int *pg_shift)
700 {
701 void *p, *new_memmap = NULL;
702 unsigned long left = 0;
703 unsigned long desc_size;
704 efi_memory_desc_t *md;
705
706 desc_size = efi.memmap.desc_size;
707
708 p = NULL;
709 while ((p = efi_map_next_entry(p))) {
710 md = p;
711
712 if (!should_map_region(md))
713 continue;
714
715 efi_map_region(md);
716
717 if (left < desc_size) {
718 new_memmap = realloc_pages(new_memmap, *pg_shift);
719 if (!new_memmap)
720 return NULL;
721
722 left += PAGE_SIZE << *pg_shift;
723 (*pg_shift)++;
724 }
725
726 memcpy(new_memmap + (*count * desc_size), md, desc_size);
727
728 left -= desc_size;
729 (*count)++;
730 }
731
732 return new_memmap;
733 }
734
735 static void __init kexec_enter_virtual_mode(void)
736 {
737 #ifdef CONFIG_KEXEC_CORE
738 efi_memory_desc_t *md;
739 unsigned int num_pages;
740
741 /*
742 * We don't do virtual mode, since we don't do runtime services, on
743 * non-native EFI.
744 */
745 if (efi_is_mixed()) {
746 efi_memmap_unmap();
747 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
748 return;
749 }
750
751 if (efi_alloc_page_tables()) {
752 pr_err("Failed to allocate EFI page tables\n");
753 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
754 return;
755 }
756
757 /*
758 * Map efi regions which were passed via setup_data. The virt_addr is a
759 * fixed addr which was used in first kernel of a kexec boot.
760 */
761 for_each_efi_memory_desc(md)
762 efi_map_region_fixed(md); /* FIXME: add error handling */
763
764 /*
765 * Unregister the early EFI memmap from efi_init() and install
766 * the new EFI memory map.
767 */
768 efi_memmap_unmap();
769
770 if (efi_memmap_init_late(efi.memmap.phys_map,
771 efi.memmap.desc_size * efi.memmap.nr_map)) {
772 pr_err("Failed to remap late EFI memory map\n");
773 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
774 return;
775 }
776
777 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
778 num_pages >>= PAGE_SHIFT;
779
780 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
781 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
782 return;
783 }
784
785 efi_sync_low_kernel_mappings();
786 efi_native_runtime_setup();
787 #endif
788 }
789
790 /*
791 * This function will switch the EFI runtime services to virtual mode.
792 * Essentially, we look through the EFI memmap and map every region that
793 * has the runtime attribute bit set in its memory descriptor into the
794 * efi_pgd page table.
795 *
796 * The new method does a pagetable switch in a preemption-safe manner
797 * so that we're in a different address space when calling a runtime
798 * function. For function arguments passing we do copy the PUDs of the
799 * kernel page table into efi_pgd prior to each call.
800 *
801 * Specially for kexec boot, efi runtime maps in previous kernel should
802 * be passed in via setup_data. In that case runtime ranges will be mapped
803 * to the same virtual addresses as the first kernel, see
804 * kexec_enter_virtual_mode().
805 */
806 static void __init __efi_enter_virtual_mode(void)
807 {
808 int count = 0, pg_shift = 0;
809 void *new_memmap = NULL;
810 efi_status_t status;
811 unsigned long pa;
812
813 if (efi_alloc_page_tables()) {
814 pr_err("Failed to allocate EFI page tables\n");
815 goto err;
816 }
817
818 efi_merge_regions();
819 new_memmap = efi_map_regions(&count, &pg_shift);
820 if (!new_memmap) {
821 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
822 goto err;
823 }
824
825 pa = __pa(new_memmap);
826
827 /*
828 * Unregister the early EFI memmap from efi_init() and install
829 * the new EFI memory map that we are about to pass to the
830 * firmware via SetVirtualAddressMap().
831 */
832 efi_memmap_unmap();
833
834 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
835 pr_err("Failed to remap late EFI memory map\n");
836 goto err;
837 }
838
839 if (efi_enabled(EFI_DBG)) {
840 pr_info("EFI runtime memory map:\n");
841 efi_print_memmap();
842 }
843
844 if (efi_setup_page_tables(pa, 1 << pg_shift))
845 goto err;
846
847 efi_sync_low_kernel_mappings();
848
849 status = efi_set_virtual_address_map(efi.memmap.desc_size * count,
850 efi.memmap.desc_size,
851 efi.memmap.desc_version,
852 (efi_memory_desc_t *)pa,
853 efi_systab_phys);
854 if (status != EFI_SUCCESS) {
855 pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n",
856 status);
857 goto err;
858 }
859
860 efi_check_for_embedded_firmwares();
861 efi_free_boot_services();
862
863 if (!efi_is_mixed())
864 efi_native_runtime_setup();
865 else
866 efi_thunk_runtime_setup();
867
868 /*
869 * Apply more restrictive page table mapping attributes now that
870 * SVAM() has been called and the firmware has performed all
871 * necessary relocation fixups for the new virtual addresses.
872 */
873 efi_runtime_update_mappings();
874
875 /* clean DUMMY object */
876 efi_delete_dummy_variable();
877 return;
878
879 err:
880 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
881 }
882
883 void __init efi_enter_virtual_mode(void)
884 {
885 if (efi_enabled(EFI_PARAVIRT))
886 return;
887
888 efi.runtime = (efi_runtime_services_t *)efi_runtime;
889
890 if (efi_setup)
891 kexec_enter_virtual_mode();
892 else
893 __efi_enter_virtual_mode();
894
895 efi_dump_pagetable();
896 }
897
898 bool efi_is_table_address(unsigned long phys_addr)
899 {
900 unsigned int i;
901
902 if (phys_addr == EFI_INVALID_TABLE_ADDR)
903 return false;
904
905 for (i = 0; i < ARRAY_SIZE(efi_tables); i++)
906 if (*(efi_tables[i]) == phys_addr)
907 return true;
908
909 return false;
910 }
911
912 char *efi_systab_show_arch(char *str)
913 {
914 if (uga_phys != EFI_INVALID_TABLE_ADDR)
915 str += sprintf(str, "UGA=0x%lx\n", uga_phys);
916 return str;
917 }
918
919 #define EFI_FIELD(var) efi_ ## var
920
921 #define EFI_ATTR_SHOW(name) \
922 static ssize_t name##_show(struct kobject *kobj, \
923 struct kobj_attribute *attr, char *buf) \
924 { \
925 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
926 }
927
928 EFI_ATTR_SHOW(fw_vendor);
929 EFI_ATTR_SHOW(runtime);
930 EFI_ATTR_SHOW(config_table);
931
932 struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
933 struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
934 struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
935
936 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
937 {
938 if (attr == &efi_attr_fw_vendor.attr) {
939 if (efi_enabled(EFI_PARAVIRT) ||
940 efi_fw_vendor == EFI_INVALID_TABLE_ADDR)
941 return 0;
942 } else if (attr == &efi_attr_runtime.attr) {
943 if (efi_runtime == EFI_INVALID_TABLE_ADDR)
944 return 0;
945 } else if (attr == &efi_attr_config_table.attr) {
946 if (efi_config_table == EFI_INVALID_TABLE_ADDR)
947 return 0;
948 }
949 return attr->mode;
950 }
951
952 enum efi_secureboot_mode __x86_ima_efi_boot_mode(void)
953 {
954 return boot_params.secure_boot;
955 }
956
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