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