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;
setup_add_efi_memmap(char * arg)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
do_add_efi_memmap(void)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 */
do_efi_soft_reserve(void)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
efi_memblock_x86_reserve_range(void)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 efi_fake_memmap_early();
230
231 WARN(efi.memmap.desc_version != 1,
232 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
233 efi.memmap.desc_version);
234
235 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
236 set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags);
237
238 return 0;
239 }
240
241 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
242 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
243 #define U64_HIGH_BIT (~(U64_MAX >> 1))
244
efi_memmap_entry_valid(const efi_memory_desc_t * md,int i)245 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
246 {
247 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
248 u64 end_hi = 0;
249 char buf[64];
250
251 if (md->num_pages == 0) {
252 end = 0;
253 } else if (md->num_pages > EFI_PAGES_MAX ||
254 EFI_PAGES_MAX - md->num_pages <
255 (md->phys_addr >> EFI_PAGE_SHIFT)) {
256 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
257 >> OVERFLOW_ADDR_SHIFT;
258
259 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
260 end_hi += 1;
261 } else {
262 return true;
263 }
264
265 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
266
267 if (end_hi) {
268 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
269 i, efi_md_typeattr_format(buf, sizeof(buf), md),
270 md->phys_addr, end_hi, end);
271 } else {
272 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
273 i, efi_md_typeattr_format(buf, sizeof(buf), md),
274 md->phys_addr, end);
275 }
276 return false;
277 }
278
efi_clean_memmap(void)279 static void __init efi_clean_memmap(void)
280 {
281 efi_memory_desc_t *out = efi.memmap.map;
282 const efi_memory_desc_t *in = out;
283 const efi_memory_desc_t *end = efi.memmap.map_end;
284 int i, n_removal;
285
286 for (i = n_removal = 0; in < end; i++) {
287 if (efi_memmap_entry_valid(in, i)) {
288 if (out != in)
289 memcpy(out, in, efi.memmap.desc_size);
290 out = (void *)out + efi.memmap.desc_size;
291 } else {
292 n_removal++;
293 }
294 in = (void *)in + efi.memmap.desc_size;
295 }
296
297 if (n_removal > 0) {
298 struct efi_memory_map_data data = {
299 .phys_map = efi.memmap.phys_map,
300 .desc_version = efi.memmap.desc_version,
301 .desc_size = efi.memmap.desc_size,
302 .size = efi.memmap.desc_size * (efi.memmap.nr_map - n_removal),
303 .flags = 0,
304 };
305
306 pr_warn("Removing %d invalid memory map entries.\n", n_removal);
307 efi_memmap_install(&data);
308 }
309 }
310
311 /*
312 * Firmware can use EfiMemoryMappedIO to request that MMIO regions be
313 * mapped by the OS so they can be accessed by EFI runtime services, but
314 * should have no other significance to the OS (UEFI r2.10, sec 7.2).
315 * However, most bootloaders and EFI stubs convert EfiMemoryMappedIO
316 * regions to E820_TYPE_RESERVED entries, which prevent Linux from
317 * allocating space from them (see remove_e820_regions()).
318 *
319 * Some platforms use EfiMemoryMappedIO entries for PCI MMCONFIG space and
320 * PCI host bridge windows, which means Linux can't allocate BAR space for
321 * hot-added devices.
322 *
323 * Remove large EfiMemoryMappedIO regions from the E820 map to avoid this
324 * problem.
325 *
326 * Retain small EfiMemoryMappedIO regions because on some platforms, these
327 * describe non-window space that's included in host bridge _CRS. If we
328 * assign that space to PCI devices, they don't work.
329 */
efi_remove_e820_mmio(void)330 static void __init efi_remove_e820_mmio(void)
331 {
332 efi_memory_desc_t *md;
333 u64 size, start, end;
334 int i = 0;
335
336 for_each_efi_memory_desc(md) {
337 if (md->type == EFI_MEMORY_MAPPED_IO) {
338 size = md->num_pages << EFI_PAGE_SHIFT;
339 start = md->phys_addr;
340 end = start + size - 1;
341 if (size >= 256*1024) {
342 pr_info("Remove mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluMB) from e820 map\n",
343 i, start, end, size >> 20);
344 e820__range_remove(start, size,
345 E820_TYPE_RESERVED, 1);
346 } else {
347 pr_info("Not removing mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluKB) from e820 map\n",
348 i, start, end, size >> 10);
349 }
350 }
351 i++;
352 }
353 }
354
efi_print_memmap(void)355 void __init efi_print_memmap(void)
356 {
357 efi_memory_desc_t *md;
358 int i = 0;
359
360 for_each_efi_memory_desc(md) {
361 char buf[64];
362
363 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
364 i++, efi_md_typeattr_format(buf, sizeof(buf), md),
365 md->phys_addr,
366 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
367 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
368 }
369 }
370
efi_systab_init(unsigned long phys)371 static int __init efi_systab_init(unsigned long phys)
372 {
373 int size = efi_enabled(EFI_64BIT) ? sizeof(efi_system_table_64_t)
374 : sizeof(efi_system_table_32_t);
375 const efi_table_hdr_t *hdr;
376 bool over4g = false;
377 void *p;
378 int ret;
379
380 hdr = p = early_memremap_ro(phys, size);
381 if (p == NULL) {
382 pr_err("Couldn't map the system table!\n");
383 return -ENOMEM;
384 }
385
386 ret = efi_systab_check_header(hdr);
387 if (ret) {
388 early_memunmap(p, size);
389 return ret;
390 }
391
392 if (efi_enabled(EFI_64BIT)) {
393 const efi_system_table_64_t *systab64 = p;
394
395 efi_runtime = systab64->runtime;
396 over4g = systab64->runtime > U32_MAX;
397
398 if (efi_setup) {
399 struct efi_setup_data *data;
400
401 data = early_memremap_ro(efi_setup, sizeof(*data));
402 if (!data) {
403 early_memunmap(p, size);
404 return -ENOMEM;
405 }
406
407 efi_fw_vendor = (unsigned long)data->fw_vendor;
408 efi_config_table = (unsigned long)data->tables;
409
410 over4g |= data->fw_vendor > U32_MAX ||
411 data->tables > U32_MAX;
412
413 early_memunmap(data, sizeof(*data));
414 } else {
415 efi_fw_vendor = systab64->fw_vendor;
416 efi_config_table = systab64->tables;
417
418 over4g |= systab64->fw_vendor > U32_MAX ||
419 systab64->tables > U32_MAX;
420 }
421 efi_nr_tables = systab64->nr_tables;
422 } else {
423 const efi_system_table_32_t *systab32 = p;
424
425 efi_fw_vendor = systab32->fw_vendor;
426 efi_runtime = systab32->runtime;
427 efi_config_table = systab32->tables;
428 efi_nr_tables = systab32->nr_tables;
429 }
430
431 efi.runtime_version = hdr->revision;
432
433 efi_systab_report_header(hdr, efi_fw_vendor);
434 early_memunmap(p, size);
435
436 if (IS_ENABLED(CONFIG_X86_32) && over4g) {
437 pr_err("EFI data located above 4GB, disabling EFI.\n");
438 return -EINVAL;
439 }
440
441 return 0;
442 }
443
efi_config_init(const efi_config_table_type_t * arch_tables)444 static int __init efi_config_init(const efi_config_table_type_t *arch_tables)
445 {
446 void *config_tables;
447 int sz, ret;
448
449 if (efi_nr_tables == 0)
450 return 0;
451
452 if (efi_enabled(EFI_64BIT))
453 sz = sizeof(efi_config_table_64_t);
454 else
455 sz = sizeof(efi_config_table_32_t);
456
457 /*
458 * Let's see what config tables the firmware passed to us.
459 */
460 config_tables = early_memremap(efi_config_table, efi_nr_tables * sz);
461 if (config_tables == NULL) {
462 pr_err("Could not map Configuration table!\n");
463 return -ENOMEM;
464 }
465
466 ret = efi_config_parse_tables(config_tables, efi_nr_tables,
467 arch_tables);
468
469 early_memunmap(config_tables, efi_nr_tables * sz);
470 return ret;
471 }
472
efi_init(void)473 void __init efi_init(void)
474 {
475 if (IS_ENABLED(CONFIG_X86_32) &&
476 (boot_params.efi_info.efi_systab_hi ||
477 boot_params.efi_info.efi_memmap_hi)) {
478 pr_info("Table located above 4GB, disabling EFI.\n");
479 return;
480 }
481
482 efi_systab_phys = boot_params.efi_info.efi_systab |
483 ((__u64)boot_params.efi_info.efi_systab_hi << 32);
484
485 if (efi_systab_init(efi_systab_phys))
486 return;
487
488 if (efi_reuse_config(efi_config_table, efi_nr_tables))
489 return;
490
491 if (efi_config_init(arch_tables))
492 return;
493
494 /*
495 * Note: We currently don't support runtime services on an EFI
496 * that doesn't match the kernel 32/64-bit mode.
497 */
498
499 if (!efi_runtime_supported())
500 pr_err("No EFI runtime due to 32/64-bit mismatch with kernel\n");
501
502 if (!efi_runtime_supported() || efi_runtime_disabled()) {
503 efi_memmap_unmap();
504 return;
505 }
506
507 /* Parse the EFI Properties table if it exists */
508 if (prop_phys != EFI_INVALID_TABLE_ADDR) {
509 efi_properties_table_t *tbl;
510
511 tbl = early_memremap_ro(prop_phys, sizeof(*tbl));
512 if (tbl == NULL) {
513 pr_err("Could not map Properties table!\n");
514 } else {
515 if (tbl->memory_protection_attribute &
516 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
517 set_bit(EFI_NX_PE_DATA, &efi.flags);
518
519 early_memunmap(tbl, sizeof(*tbl));
520 }
521 }
522
523 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
524 efi_clean_memmap();
525
526 efi_remove_e820_mmio();
527
528 if (efi_enabled(EFI_DBG))
529 efi_print_memmap();
530 }
531
532 /* Merge contiguous regions of the same type and attribute */
efi_merge_regions(void)533 static void __init efi_merge_regions(void)
534 {
535 efi_memory_desc_t *md, *prev_md = NULL;
536
537 for_each_efi_memory_desc(md) {
538 u64 prev_size;
539
540 if (!prev_md) {
541 prev_md = md;
542 continue;
543 }
544
545 if (prev_md->type != md->type ||
546 prev_md->attribute != md->attribute) {
547 prev_md = md;
548 continue;
549 }
550
551 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
552
553 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
554 prev_md->num_pages += md->num_pages;
555 md->type = EFI_RESERVED_TYPE;
556 md->attribute = 0;
557 continue;
558 }
559 prev_md = md;
560 }
561 }
562
realloc_pages(void * old_memmap,int old_shift)563 static void *realloc_pages(void *old_memmap, int old_shift)
564 {
565 void *ret;
566
567 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
568 if (!ret)
569 goto out;
570
571 /*
572 * A first-time allocation doesn't have anything to copy.
573 */
574 if (!old_memmap)
575 return ret;
576
577 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
578
579 out:
580 free_pages((unsigned long)old_memmap, old_shift);
581 return ret;
582 }
583
584 /*
585 * Iterate the EFI memory map in reverse order because the regions
586 * will be mapped top-down. The end result is the same as if we had
587 * mapped things forward, but doesn't require us to change the
588 * existing implementation of efi_map_region().
589 */
efi_map_next_entry_reverse(void * entry)590 static inline void *efi_map_next_entry_reverse(void *entry)
591 {
592 /* Initial call */
593 if (!entry)
594 return efi.memmap.map_end - efi.memmap.desc_size;
595
596 entry -= efi.memmap.desc_size;
597 if (entry < efi.memmap.map)
598 return NULL;
599
600 return entry;
601 }
602
603 /*
604 * efi_map_next_entry - Return the next EFI memory map descriptor
605 * @entry: Previous EFI memory map descriptor
606 *
607 * This is a helper function to iterate over the EFI memory map, which
608 * we do in different orders depending on the current configuration.
609 *
610 * To begin traversing the memory map @entry must be %NULL.
611 *
612 * Returns %NULL when we reach the end of the memory map.
613 */
efi_map_next_entry(void * entry)614 static void *efi_map_next_entry(void *entry)
615 {
616 if (efi_enabled(EFI_64BIT)) {
617 /*
618 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
619 * config table feature requires us to map all entries
620 * in the same order as they appear in the EFI memory
621 * map. That is to say, entry N must have a lower
622 * virtual address than entry N+1. This is because the
623 * firmware toolchain leaves relative references in
624 * the code/data sections, which are split and become
625 * separate EFI memory regions. Mapping things
626 * out-of-order leads to the firmware accessing
627 * unmapped addresses.
628 *
629 * Since we need to map things this way whether or not
630 * the kernel actually makes use of
631 * EFI_PROPERTIES_TABLE, let's just switch to this
632 * scheme by default for 64-bit.
633 */
634 return efi_map_next_entry_reverse(entry);
635 }
636
637 /* Initial call */
638 if (!entry)
639 return efi.memmap.map;
640
641 entry += efi.memmap.desc_size;
642 if (entry >= efi.memmap.map_end)
643 return NULL;
644
645 return entry;
646 }
647
should_map_region(efi_memory_desc_t * md)648 static bool should_map_region(efi_memory_desc_t *md)
649 {
650 /*
651 * Runtime regions always require runtime mappings (obviously).
652 */
653 if (md->attribute & EFI_MEMORY_RUNTIME)
654 return true;
655
656 /*
657 * 32-bit EFI doesn't suffer from the bug that requires us to
658 * reserve boot services regions, and mixed mode support
659 * doesn't exist for 32-bit kernels.
660 */
661 if (IS_ENABLED(CONFIG_X86_32))
662 return false;
663
664 /*
665 * EFI specific purpose memory may be reserved by default
666 * depending on kernel config and boot options.
667 */
668 if (md->type == EFI_CONVENTIONAL_MEMORY &&
669 efi_soft_reserve_enabled() &&
670 (md->attribute & EFI_MEMORY_SP))
671 return false;
672
673 /*
674 * Map all of RAM so that we can access arguments in the 1:1
675 * mapping when making EFI runtime calls.
676 */
677 if (efi_is_mixed()) {
678 if (md->type == EFI_CONVENTIONAL_MEMORY ||
679 md->type == EFI_LOADER_DATA ||
680 md->type == EFI_LOADER_CODE)
681 return true;
682 }
683
684 /*
685 * Map boot services regions as a workaround for buggy
686 * firmware that accesses them even when they shouldn't.
687 *
688 * See efi_{reserve,free}_boot_services().
689 */
690 if (md->type == EFI_BOOT_SERVICES_CODE ||
691 md->type == EFI_BOOT_SERVICES_DATA)
692 return true;
693
694 return false;
695 }
696
697 /*
698 * Map the efi memory ranges of the runtime services and update new_mmap with
699 * virtual addresses.
700 */
efi_map_regions(int * count,int * pg_shift)701 static void * __init efi_map_regions(int *count, int *pg_shift)
702 {
703 void *p, *new_memmap = NULL;
704 unsigned long left = 0;
705 unsigned long desc_size;
706 efi_memory_desc_t *md;
707
708 desc_size = efi.memmap.desc_size;
709
710 p = NULL;
711 while ((p = efi_map_next_entry(p))) {
712 md = p;
713
714 if (!should_map_region(md))
715 continue;
716
717 efi_map_region(md);
718
719 if (left < desc_size) {
720 new_memmap = realloc_pages(new_memmap, *pg_shift);
721 if (!new_memmap)
722 return NULL;
723
724 left += PAGE_SIZE << *pg_shift;
725 (*pg_shift)++;
726 }
727
728 memcpy(new_memmap + (*count * desc_size), md, desc_size);
729
730 left -= desc_size;
731 (*count)++;
732 }
733
734 return new_memmap;
735 }
736
kexec_enter_virtual_mode(void)737 static void __init kexec_enter_virtual_mode(void)
738 {
739 #ifdef CONFIG_KEXEC_CORE
740 efi_memory_desc_t *md;
741 unsigned int num_pages;
742
743 /*
744 * We don't do virtual mode, since we don't do runtime services, on
745 * non-native EFI.
746 */
747 if (efi_is_mixed()) {
748 efi_memmap_unmap();
749 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
750 return;
751 }
752
753 if (efi_alloc_page_tables()) {
754 pr_err("Failed to allocate EFI page tables\n");
755 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
756 return;
757 }
758
759 /*
760 * Map efi regions which were passed via setup_data. The virt_addr is a
761 * fixed addr which was used in first kernel of a kexec boot.
762 */
763 for_each_efi_memory_desc(md)
764 efi_map_region_fixed(md); /* FIXME: add error handling */
765
766 /*
767 * Unregister the early EFI memmap from efi_init() and install
768 * the new EFI memory map.
769 */
770 efi_memmap_unmap();
771
772 if (efi_memmap_init_late(efi.memmap.phys_map,
773 efi.memmap.desc_size * efi.memmap.nr_map)) {
774 pr_err("Failed to remap late EFI memory map\n");
775 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
776 return;
777 }
778
779 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
780 num_pages >>= PAGE_SHIFT;
781
782 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
783 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
784 return;
785 }
786
787 efi_sync_low_kernel_mappings();
788 efi_native_runtime_setup();
789 #endif
790 }
791
792 /*
793 * This function will switch the EFI runtime services to virtual mode.
794 * Essentially, we look through the EFI memmap and map every region that
795 * has the runtime attribute bit set in its memory descriptor into the
796 * efi_pgd page table.
797 *
798 * The new method does a pagetable switch in a preemption-safe manner
799 * so that we're in a different address space when calling a runtime
800 * function. For function arguments passing we do copy the PUDs of the
801 * kernel page table into efi_pgd prior to each call.
802 *
803 * Specially for kexec boot, efi runtime maps in previous kernel should
804 * be passed in via setup_data. In that case runtime ranges will be mapped
805 * to the same virtual addresses as the first kernel, see
806 * kexec_enter_virtual_mode().
807 */
__efi_enter_virtual_mode(void)808 static void __init __efi_enter_virtual_mode(void)
809 {
810 int count = 0, pg_shift = 0;
811 void *new_memmap = NULL;
812 efi_status_t status;
813 unsigned long pa;
814
815 if (efi_alloc_page_tables()) {
816 pr_err("Failed to allocate EFI page tables\n");
817 goto err;
818 }
819
820 efi_merge_regions();
821 new_memmap = efi_map_regions(&count, &pg_shift);
822 if (!new_memmap) {
823 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
824 goto err;
825 }
826
827 pa = __pa(new_memmap);
828
829 /*
830 * Unregister the early EFI memmap from efi_init() and install
831 * the new EFI memory map that we are about to pass to the
832 * firmware via SetVirtualAddressMap().
833 */
834 efi_memmap_unmap();
835
836 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
837 pr_err("Failed to remap late EFI memory map\n");
838 goto err;
839 }
840
841 if (efi_enabled(EFI_DBG)) {
842 pr_info("EFI runtime memory map:\n");
843 efi_print_memmap();
844 }
845
846 if (efi_setup_page_tables(pa, 1 << pg_shift))
847 goto err;
848
849 efi_sync_low_kernel_mappings();
850
851 status = efi_set_virtual_address_map(efi.memmap.desc_size * count,
852 efi.memmap.desc_size,
853 efi.memmap.desc_version,
854 (efi_memory_desc_t *)pa,
855 efi_systab_phys);
856 if (status != EFI_SUCCESS) {
857 pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n",
858 status);
859 goto err;
860 }
861
862 efi_check_for_embedded_firmwares();
863 efi_free_boot_services();
864
865 if (!efi_is_mixed())
866 efi_native_runtime_setup();
867 else
868 efi_thunk_runtime_setup();
869
870 /*
871 * Apply more restrictive page table mapping attributes now that
872 * SVAM() has been called and the firmware has performed all
873 * necessary relocation fixups for the new virtual addresses.
874 */
875 efi_runtime_update_mappings();
876
877 /* clean DUMMY object */
878 efi_delete_dummy_variable();
879 return;
880
881 err:
882 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
883 }
884
efi_enter_virtual_mode(void)885 void __init efi_enter_virtual_mode(void)
886 {
887 if (efi_enabled(EFI_PARAVIRT))
888 return;
889
890 efi.runtime = (efi_runtime_services_t *)efi_runtime;
891
892 if (efi_setup)
893 kexec_enter_virtual_mode();
894 else
895 __efi_enter_virtual_mode();
896
897 efi_dump_pagetable();
898 }
899
efi_is_table_address(unsigned long phys_addr)900 bool efi_is_table_address(unsigned long phys_addr)
901 {
902 unsigned int i;
903
904 if (phys_addr == EFI_INVALID_TABLE_ADDR)
905 return false;
906
907 for (i = 0; i < ARRAY_SIZE(efi_tables); i++)
908 if (*(efi_tables[i]) == phys_addr)
909 return true;
910
911 return false;
912 }
913
efi_systab_show_arch(char * str)914 char *efi_systab_show_arch(char *str)
915 {
916 if (uga_phys != EFI_INVALID_TABLE_ADDR)
917 str += sprintf(str, "UGA=0x%lx\n", uga_phys);
918 return str;
919 }
920
921 #define EFI_FIELD(var) efi_ ## var
922
923 #define EFI_ATTR_SHOW(name) \
924 static ssize_t name##_show(struct kobject *kobj, \
925 struct kobj_attribute *attr, char *buf) \
926 { \
927 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
928 }
929
930 EFI_ATTR_SHOW(fw_vendor);
931 EFI_ATTR_SHOW(runtime);
932 EFI_ATTR_SHOW(config_table);
933
934 struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
935 struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
936 struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
937
efi_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)938 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
939 {
940 if (attr == &efi_attr_fw_vendor.attr) {
941 if (efi_enabled(EFI_PARAVIRT) ||
942 efi_fw_vendor == EFI_INVALID_TABLE_ADDR)
943 return 0;
944 } else if (attr == &efi_attr_runtime.attr) {
945 if (efi_runtime == EFI_INVALID_TABLE_ADDR)
946 return 0;
947 } else if (attr == &efi_attr_config_table.attr) {
948 if (efi_config_table == EFI_INVALID_TABLE_ADDR)
949 return 0;
950 }
951 return attr->mode;
952 }
953
__x86_ima_efi_boot_mode(void)954 enum efi_secureboot_mode __x86_ima_efi_boot_mode(void)
955 {
956 return boot_params.secure_boot;
957 }
958