1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * efi.c - EFI subsystem
4 *
5 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
6 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
7 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
8 *
9 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
10 * allowing the efivarfs to be mounted or the efivars module to be loaded.
11 * The existance of /sys/firmware/efi may also be used by userspace to
12 * determine that the system supports EFI.
13 */
14
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16
17 #include <linux/kobject.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/device.h>
21 #include <linux/efi.h>
22 #include <linux/of.h>
23 #include <linux/of_fdt.h>
24 #include <linux/io.h>
25 #include <linux/kexec.h>
26 #include <linux/platform_device.h>
27 #include <linux/random.h>
28 #include <linux/reboot.h>
29 #include <linux/slab.h>
30 #include <linux/acpi.h>
31 #include <linux/ucs2_string.h>
32 #include <linux/memblock.h>
33 #include <linux/security.h>
34
35 #include <asm/early_ioremap.h>
36
37 struct efi __read_mostly efi = {
38 .mps = EFI_INVALID_TABLE_ADDR,
39 .acpi = EFI_INVALID_TABLE_ADDR,
40 .acpi20 = EFI_INVALID_TABLE_ADDR,
41 .smbios = EFI_INVALID_TABLE_ADDR,
42 .smbios3 = EFI_INVALID_TABLE_ADDR,
43 .boot_info = EFI_INVALID_TABLE_ADDR,
44 .hcdp = EFI_INVALID_TABLE_ADDR,
45 .uga = EFI_INVALID_TABLE_ADDR,
46 .fw_vendor = EFI_INVALID_TABLE_ADDR,
47 .runtime = EFI_INVALID_TABLE_ADDR,
48 .config_table = EFI_INVALID_TABLE_ADDR,
49 .esrt = EFI_INVALID_TABLE_ADDR,
50 .properties_table = EFI_INVALID_TABLE_ADDR,
51 .mem_attr_table = EFI_INVALID_TABLE_ADDR,
52 .rng_seed = EFI_INVALID_TABLE_ADDR,
53 .tpm_log = EFI_INVALID_TABLE_ADDR,
54 .tpm_final_log = EFI_INVALID_TABLE_ADDR,
55 .mem_reserve = EFI_INVALID_TABLE_ADDR,
56 };
57 EXPORT_SYMBOL(efi);
58
59 struct mm_struct efi_mm = {
60 .mm_rb = RB_ROOT,
61 .mm_users = ATOMIC_INIT(2),
62 .mm_count = ATOMIC_INIT(1),
63 .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
64 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
65 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
66 .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
67 };
68
69 struct workqueue_struct *efi_rts_wq;
70
71 static bool disable_runtime;
setup_noefi(char * arg)72 static int __init setup_noefi(char *arg)
73 {
74 disable_runtime = true;
75 return 0;
76 }
77 early_param("noefi", setup_noefi);
78
efi_runtime_disabled(void)79 bool efi_runtime_disabled(void)
80 {
81 return disable_runtime;
82 }
83
parse_efi_cmdline(char * str)84 static int __init parse_efi_cmdline(char *str)
85 {
86 if (!str) {
87 pr_warn("need at least one option\n");
88 return -EINVAL;
89 }
90
91 if (parse_option_str(str, "debug"))
92 set_bit(EFI_DBG, &efi.flags);
93
94 if (parse_option_str(str, "noruntime"))
95 disable_runtime = true;
96
97 return 0;
98 }
99 early_param("efi", parse_efi_cmdline);
100
101 struct kobject *efi_kobj;
102
103 /*
104 * Let's not leave out systab information that snuck into
105 * the efivars driver
106 * Note, do not add more fields in systab sysfs file as it breaks sysfs
107 * one value per file rule!
108 */
systab_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)109 static ssize_t systab_show(struct kobject *kobj,
110 struct kobj_attribute *attr, char *buf)
111 {
112 char *str = buf;
113
114 if (!kobj || !buf)
115 return -EINVAL;
116
117 if (efi.mps != EFI_INVALID_TABLE_ADDR)
118 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
119 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
120 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
121 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
122 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
123 /*
124 * If both SMBIOS and SMBIOS3 entry points are implemented, the
125 * SMBIOS3 entry point shall be preferred, so we list it first to
126 * let applications stop parsing after the first match.
127 */
128 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
129 str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
130 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
131 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
132 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
133 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
134 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
135 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
136 if (efi.uga != EFI_INVALID_TABLE_ADDR)
137 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
138
139 return str - buf;
140 }
141
142 static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
143
144 #define EFI_FIELD(var) efi.var
145
146 #define EFI_ATTR_SHOW(name) \
147 static ssize_t name##_show(struct kobject *kobj, \
148 struct kobj_attribute *attr, char *buf) \
149 { \
150 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
151 }
152
153 EFI_ATTR_SHOW(fw_vendor);
154 EFI_ATTR_SHOW(runtime);
155 EFI_ATTR_SHOW(config_table);
156
fw_platform_size_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)157 static ssize_t fw_platform_size_show(struct kobject *kobj,
158 struct kobj_attribute *attr, char *buf)
159 {
160 return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
161 }
162
163 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
164 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
165 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
166 static struct kobj_attribute efi_attr_fw_platform_size =
167 __ATTR_RO(fw_platform_size);
168
169 static struct attribute *efi_subsys_attrs[] = {
170 &efi_attr_systab.attr,
171 &efi_attr_fw_vendor.attr,
172 &efi_attr_runtime.attr,
173 &efi_attr_config_table.attr,
174 &efi_attr_fw_platform_size.attr,
175 NULL,
176 };
177
efi_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)178 static umode_t efi_attr_is_visible(struct kobject *kobj,
179 struct attribute *attr, int n)
180 {
181 if (attr == &efi_attr_fw_vendor.attr) {
182 if (efi_enabled(EFI_PARAVIRT) ||
183 efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
184 return 0;
185 } else if (attr == &efi_attr_runtime.attr) {
186 if (efi.runtime == EFI_INVALID_TABLE_ADDR)
187 return 0;
188 } else if (attr == &efi_attr_config_table.attr) {
189 if (efi.config_table == EFI_INVALID_TABLE_ADDR)
190 return 0;
191 }
192
193 return attr->mode;
194 }
195
196 static const struct attribute_group efi_subsys_attr_group = {
197 .attrs = efi_subsys_attrs,
198 .is_visible = efi_attr_is_visible,
199 };
200
201 static struct efivars generic_efivars;
202 static struct efivar_operations generic_ops;
203
generic_ops_register(void)204 static int generic_ops_register(void)
205 {
206 generic_ops.get_variable = efi.get_variable;
207 generic_ops.set_variable = efi.set_variable;
208 generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
209 generic_ops.get_next_variable = efi.get_next_variable;
210 generic_ops.query_variable_store = efi_query_variable_store;
211
212 return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
213 }
214
generic_ops_unregister(void)215 static void generic_ops_unregister(void)
216 {
217 efivars_unregister(&generic_efivars);
218 }
219
220 #if IS_ENABLED(CONFIG_ACPI)
221 #define EFIVAR_SSDT_NAME_MAX 16
222 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
efivar_ssdt_setup(char * str)223 static int __init efivar_ssdt_setup(char *str)
224 {
225 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
226
227 if (ret)
228 return ret;
229
230 if (strlen(str) < sizeof(efivar_ssdt))
231 memcpy(efivar_ssdt, str, strlen(str));
232 else
233 pr_warn("efivar_ssdt: name too long: %s\n", str);
234 return 0;
235 }
236 __setup("efivar_ssdt=", efivar_ssdt_setup);
237
efivar_ssdt_iter(efi_char16_t * name,efi_guid_t vendor,unsigned long name_size,void * data)238 static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
239 unsigned long name_size, void *data)
240 {
241 struct efivar_entry *entry;
242 struct list_head *list = data;
243 char utf8_name[EFIVAR_SSDT_NAME_MAX];
244 int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
245
246 ucs2_as_utf8(utf8_name, name, limit - 1);
247 if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
248 return 0;
249
250 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
251 if (!entry)
252 return 0;
253
254 memcpy(entry->var.VariableName, name, name_size);
255 memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
256
257 efivar_entry_add(entry, list);
258
259 return 0;
260 }
261
efivar_ssdt_load(void)262 static __init int efivar_ssdt_load(void)
263 {
264 LIST_HEAD(entries);
265 struct efivar_entry *entry, *aux;
266 unsigned long size;
267 void *data;
268 int ret;
269
270 if (!efivar_ssdt[0])
271 return 0;
272
273 ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
274
275 list_for_each_entry_safe(entry, aux, &entries, list) {
276 pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
277 &entry->var.VendorGuid);
278
279 list_del(&entry->list);
280
281 ret = efivar_entry_size(entry, &size);
282 if (ret) {
283 pr_err("failed to get var size\n");
284 goto free_entry;
285 }
286
287 data = kmalloc(size, GFP_KERNEL);
288 if (!data) {
289 ret = -ENOMEM;
290 goto free_entry;
291 }
292
293 ret = efivar_entry_get(entry, NULL, &size, data);
294 if (ret) {
295 pr_err("failed to get var data\n");
296 goto free_data;
297 }
298
299 ret = acpi_load_table(data);
300 if (ret) {
301 pr_err("failed to load table: %d\n", ret);
302 goto free_data;
303 }
304
305 goto free_entry;
306
307 free_data:
308 kfree(data);
309
310 free_entry:
311 kfree(entry);
312 }
313
314 return ret;
315 }
316 #else
efivar_ssdt_load(void)317 static inline int efivar_ssdt_load(void) { return 0; }
318 #endif
319
320 /*
321 * We register the efi subsystem with the firmware subsystem and the
322 * efivars subsystem with the efi subsystem, if the system was booted with
323 * EFI.
324 */
efisubsys_init(void)325 static int __init efisubsys_init(void)
326 {
327 int error;
328
329 if (!efi_enabled(EFI_BOOT))
330 return 0;
331
332 /*
333 * Since we process only one efi_runtime_service() at a time, an
334 * ordered workqueue (which creates only one execution context)
335 * should suffice all our needs.
336 */
337 efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
338 if (!efi_rts_wq) {
339 pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
340 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
341 return 0;
342 }
343
344 /* We register the efi directory at /sys/firmware/efi */
345 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
346 if (!efi_kobj) {
347 pr_err("efi: Firmware registration failed.\n");
348 return -ENOMEM;
349 }
350
351 error = generic_ops_register();
352 if (error)
353 goto err_put;
354
355 if (efi_enabled(EFI_RUNTIME_SERVICES))
356 efivar_ssdt_load();
357
358 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
359 if (error) {
360 pr_err("efi: Sysfs attribute export failed with error %d.\n",
361 error);
362 goto err_unregister;
363 }
364
365 error = efi_runtime_map_init(efi_kobj);
366 if (error)
367 goto err_remove_group;
368
369 /* and the standard mountpoint for efivarfs */
370 error = sysfs_create_mount_point(efi_kobj, "efivars");
371 if (error) {
372 pr_err("efivars: Subsystem registration failed.\n");
373 goto err_remove_group;
374 }
375
376 return 0;
377
378 err_remove_group:
379 sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
380 err_unregister:
381 generic_ops_unregister();
382 err_put:
383 kobject_put(efi_kobj);
384 return error;
385 }
386
387 subsys_initcall(efisubsys_init);
388
389 /*
390 * Find the efi memory descriptor for a given physical address. Given a
391 * physical address, determine if it exists within an EFI Memory Map entry,
392 * and if so, populate the supplied memory descriptor with the appropriate
393 * data.
394 */
efi_mem_desc_lookup(u64 phys_addr,efi_memory_desc_t * out_md)395 int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
396 {
397 efi_memory_desc_t *md;
398
399 if (!efi_enabled(EFI_MEMMAP)) {
400 pr_err_once("EFI_MEMMAP is not enabled.\n");
401 return -EINVAL;
402 }
403
404 if (!out_md) {
405 pr_err_once("out_md is null.\n");
406 return -EINVAL;
407 }
408
409 for_each_efi_memory_desc(md) {
410 u64 size;
411 u64 end;
412
413 size = md->num_pages << EFI_PAGE_SHIFT;
414 end = md->phys_addr + size;
415 if (phys_addr >= md->phys_addr && phys_addr < end) {
416 memcpy(out_md, md, sizeof(*out_md));
417 return 0;
418 }
419 }
420 return -ENOENT;
421 }
422
423 /*
424 * Calculate the highest address of an efi memory descriptor.
425 */
efi_mem_desc_end(efi_memory_desc_t * md)426 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
427 {
428 u64 size = md->num_pages << EFI_PAGE_SHIFT;
429 u64 end = md->phys_addr + size;
430 return end;
431 }
432
efi_arch_mem_reserve(phys_addr_t addr,u64 size)433 void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
434
435 /**
436 * efi_mem_reserve - Reserve an EFI memory region
437 * @addr: Physical address to reserve
438 * @size: Size of reservation
439 *
440 * Mark a region as reserved from general kernel allocation and
441 * prevent it being released by efi_free_boot_services().
442 *
443 * This function should be called drivers once they've parsed EFI
444 * configuration tables to figure out where their data lives, e.g.
445 * efi_esrt_init().
446 */
efi_mem_reserve(phys_addr_t addr,u64 size)447 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
448 {
449 if (!memblock_is_region_reserved(addr, size))
450 memblock_reserve(addr, size);
451
452 /*
453 * Some architectures (x86) reserve all boot services ranges
454 * until efi_free_boot_services() because of buggy firmware
455 * implementations. This means the above memblock_reserve() is
456 * superfluous on x86 and instead what it needs to do is
457 * ensure the @start, @size is not freed.
458 */
459 efi_arch_mem_reserve(addr, size);
460 }
461
462 static __initdata efi_config_table_type_t common_tables[] = {
463 {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
464 {ACPI_TABLE_GUID, "ACPI", &efi.acpi},
465 {HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
466 {MPS_TABLE_GUID, "MPS", &efi.mps},
467 {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
468 {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
469 {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
470 {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
471 {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
472 {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
473 {LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed},
474 {LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
475 {LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log},
476 {LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &efi.mem_reserve},
477 #ifdef CONFIG_EFI_RCI2_TABLE
478 {DELLEMC_EFI_RCI2_TABLE_GUID, NULL, &rci2_table_phys},
479 #endif
480 {NULL_GUID, NULL, NULL},
481 };
482
match_config_table(efi_guid_t * guid,unsigned long table,efi_config_table_type_t * table_types)483 static __init int match_config_table(efi_guid_t *guid,
484 unsigned long table,
485 efi_config_table_type_t *table_types)
486 {
487 int i;
488
489 if (table_types) {
490 for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
491 if (!efi_guidcmp(*guid, table_types[i].guid)) {
492 *(table_types[i].ptr) = table;
493 if (table_types[i].name)
494 pr_cont(" %s=0x%lx ",
495 table_types[i].name, table);
496 return 1;
497 }
498 }
499 }
500
501 return 0;
502 }
503
efi_config_parse_tables(void * config_tables,int count,int sz,efi_config_table_type_t * arch_tables)504 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
505 efi_config_table_type_t *arch_tables)
506 {
507 void *tablep;
508 int i;
509
510 tablep = config_tables;
511 pr_info("");
512 for (i = 0; i < count; i++) {
513 efi_guid_t guid;
514 unsigned long table;
515
516 if (efi_enabled(EFI_64BIT)) {
517 u64 table64;
518 guid = ((efi_config_table_64_t *)tablep)->guid;
519 table64 = ((efi_config_table_64_t *)tablep)->table;
520 table = table64;
521 #ifndef CONFIG_64BIT
522 if (table64 >> 32) {
523 pr_cont("\n");
524 pr_err("Table located above 4GB, disabling EFI.\n");
525 return -EINVAL;
526 }
527 #endif
528 } else {
529 guid = ((efi_config_table_32_t *)tablep)->guid;
530 table = ((efi_config_table_32_t *)tablep)->table;
531 }
532
533 if (!match_config_table(&guid, table, common_tables))
534 match_config_table(&guid, table, arch_tables);
535
536 tablep += sz;
537 }
538 pr_cont("\n");
539 set_bit(EFI_CONFIG_TABLES, &efi.flags);
540
541 if (efi.rng_seed != EFI_INVALID_TABLE_ADDR) {
542 struct linux_efi_random_seed *seed;
543 u32 size = 0;
544
545 seed = early_memremap(efi.rng_seed, sizeof(*seed));
546 if (seed != NULL) {
547 size = seed->size;
548 early_memunmap(seed, sizeof(*seed));
549 } else {
550 pr_err("Could not map UEFI random seed!\n");
551 }
552 if (size > 0) {
553 seed = early_memremap(efi.rng_seed,
554 sizeof(*seed) + size);
555 if (seed != NULL) {
556 pr_notice("seeding entropy pool\n");
557 add_bootloader_randomness(seed->bits, seed->size);
558 early_memunmap(seed, sizeof(*seed) + size);
559 } else {
560 pr_err("Could not map UEFI random seed!\n");
561 }
562 }
563 }
564
565 if (efi_enabled(EFI_MEMMAP))
566 efi_memattr_init();
567
568 efi_tpm_eventlog_init();
569
570 /* Parse the EFI Properties table if it exists */
571 if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
572 efi_properties_table_t *tbl;
573
574 tbl = early_memremap(efi.properties_table, sizeof(*tbl));
575 if (tbl == NULL) {
576 pr_err("Could not map Properties table!\n");
577 return -ENOMEM;
578 }
579
580 if (tbl->memory_protection_attribute &
581 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
582 set_bit(EFI_NX_PE_DATA, &efi.flags);
583
584 early_memunmap(tbl, sizeof(*tbl));
585 }
586
587 if (efi.mem_reserve != EFI_INVALID_TABLE_ADDR) {
588 unsigned long prsv = efi.mem_reserve;
589
590 while (prsv) {
591 struct linux_efi_memreserve *rsv;
592 u8 *p;
593 int i;
594
595 /*
596 * Just map a full page: that is what we will get
597 * anyway, and it permits us to map the entire entry
598 * before knowing its size.
599 */
600 p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
601 PAGE_SIZE);
602 if (p == NULL) {
603 pr_err("Could not map UEFI memreserve entry!\n");
604 return -ENOMEM;
605 }
606
607 rsv = (void *)(p + prsv % PAGE_SIZE);
608
609 /* reserve the entry itself */
610 memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size));
611
612 for (i = 0; i < atomic_read(&rsv->count); i++) {
613 memblock_reserve(rsv->entry[i].base,
614 rsv->entry[i].size);
615 }
616
617 prsv = rsv->next;
618 early_memunmap(p, PAGE_SIZE);
619 }
620 }
621
622 return 0;
623 }
624
efi_config_init(efi_config_table_type_t * arch_tables)625 int __init efi_config_init(efi_config_table_type_t *arch_tables)
626 {
627 void *config_tables;
628 int sz, ret;
629
630 if (efi.systab->nr_tables == 0)
631 return 0;
632
633 if (efi_enabled(EFI_64BIT))
634 sz = sizeof(efi_config_table_64_t);
635 else
636 sz = sizeof(efi_config_table_32_t);
637
638 /*
639 * Let's see what config tables the firmware passed to us.
640 */
641 config_tables = early_memremap(efi.systab->tables,
642 efi.systab->nr_tables * sz);
643 if (config_tables == NULL) {
644 pr_err("Could not map Configuration table!\n");
645 return -ENOMEM;
646 }
647
648 ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
649 arch_tables);
650
651 early_memunmap(config_tables, efi.systab->nr_tables * sz);
652 return ret;
653 }
654
655 #ifdef CONFIG_EFI_VARS_MODULE
efi_load_efivars(void)656 static int __init efi_load_efivars(void)
657 {
658 struct platform_device *pdev;
659
660 if (!efi_enabled(EFI_RUNTIME_SERVICES))
661 return 0;
662
663 pdev = platform_device_register_simple("efivars", 0, NULL, 0);
664 return PTR_ERR_OR_ZERO(pdev);
665 }
666 device_initcall(efi_load_efivars);
667 #endif
668
669 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
670
671 #define UEFI_PARAM(name, prop, field) \
672 { \
673 { name }, \
674 { prop }, \
675 offsetof(struct efi_fdt_params, field), \
676 FIELD_SIZEOF(struct efi_fdt_params, field) \
677 }
678
679 struct params {
680 const char name[32];
681 const char propname[32];
682 int offset;
683 int size;
684 };
685
686 static __initdata struct params fdt_params[] = {
687 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
688 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
689 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
690 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
691 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
692 };
693
694 static __initdata struct params xen_fdt_params[] = {
695 UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),
696 UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),
697 UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),
698 UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),
699 UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)
700 };
701
702 #define EFI_FDT_PARAMS_SIZE ARRAY_SIZE(fdt_params)
703
704 static __initdata struct {
705 const char *uname;
706 const char *subnode;
707 struct params *params;
708 } dt_params[] = {
709 { "hypervisor", "uefi", xen_fdt_params },
710 { "chosen", NULL, fdt_params },
711 };
712
713 struct param_info {
714 int found;
715 void *params;
716 const char *missing;
717 };
718
__find_uefi_params(unsigned long node,struct param_info * info,struct params * params)719 static int __init __find_uefi_params(unsigned long node,
720 struct param_info *info,
721 struct params *params)
722 {
723 const void *prop;
724 void *dest;
725 u64 val;
726 int i, len;
727
728 for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {
729 prop = of_get_flat_dt_prop(node, params[i].propname, &len);
730 if (!prop) {
731 info->missing = params[i].name;
732 return 0;
733 }
734
735 dest = info->params + params[i].offset;
736 info->found++;
737
738 val = of_read_number(prop, len / sizeof(u32));
739
740 if (params[i].size == sizeof(u32))
741 *(u32 *)dest = val;
742 else
743 *(u64 *)dest = val;
744
745 if (efi_enabled(EFI_DBG))
746 pr_info(" %s: 0x%0*llx\n", params[i].name,
747 params[i].size * 2, val);
748 }
749
750 return 1;
751 }
752
fdt_find_uefi_params(unsigned long node,const char * uname,int depth,void * data)753 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
754 int depth, void *data)
755 {
756 struct param_info *info = data;
757 int i;
758
759 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
760 const char *subnode = dt_params[i].subnode;
761
762 if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
763 info->missing = dt_params[i].params[0].name;
764 continue;
765 }
766
767 if (subnode) {
768 int err = of_get_flat_dt_subnode_by_name(node, subnode);
769
770 if (err < 0)
771 return 0;
772
773 node = err;
774 }
775
776 return __find_uefi_params(node, info, dt_params[i].params);
777 }
778
779 return 0;
780 }
781
efi_get_fdt_params(struct efi_fdt_params * params)782 int __init efi_get_fdt_params(struct efi_fdt_params *params)
783 {
784 struct param_info info;
785 int ret;
786
787 pr_info("Getting EFI parameters from FDT:\n");
788
789 info.found = 0;
790 info.params = params;
791
792 ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
793 if (!info.found)
794 pr_info("UEFI not found.\n");
795 else if (!ret)
796 pr_err("Can't find '%s' in device tree!\n",
797 info.missing);
798
799 return ret;
800 }
801 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
802
803 static __initdata char memory_type_name[][20] = {
804 "Reserved",
805 "Loader Code",
806 "Loader Data",
807 "Boot Code",
808 "Boot Data",
809 "Runtime Code",
810 "Runtime Data",
811 "Conventional Memory",
812 "Unusable Memory",
813 "ACPI Reclaim Memory",
814 "ACPI Memory NVS",
815 "Memory Mapped I/O",
816 "MMIO Port Space",
817 "PAL Code",
818 "Persistent Memory",
819 };
820
efi_md_typeattr_format(char * buf,size_t size,const efi_memory_desc_t * md)821 char * __init efi_md_typeattr_format(char *buf, size_t size,
822 const efi_memory_desc_t *md)
823 {
824 char *pos;
825 int type_len;
826 u64 attr;
827
828 pos = buf;
829 if (md->type >= ARRAY_SIZE(memory_type_name))
830 type_len = snprintf(pos, size, "[type=%u", md->type);
831 else
832 type_len = snprintf(pos, size, "[%-*s",
833 (int)(sizeof(memory_type_name[0]) - 1),
834 memory_type_name[md->type]);
835 if (type_len >= size)
836 return buf;
837
838 pos += type_len;
839 size -= type_len;
840
841 attr = md->attribute;
842 if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
843 EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
844 EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
845 EFI_MEMORY_NV |
846 EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
847 snprintf(pos, size, "|attr=0x%016llx]",
848 (unsigned long long)attr);
849 else
850 snprintf(pos, size,
851 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
852 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
853 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
854 attr & EFI_MEMORY_NV ? "NV" : "",
855 attr & EFI_MEMORY_XP ? "XP" : "",
856 attr & EFI_MEMORY_RP ? "RP" : "",
857 attr & EFI_MEMORY_WP ? "WP" : "",
858 attr & EFI_MEMORY_RO ? "RO" : "",
859 attr & EFI_MEMORY_UCE ? "UCE" : "",
860 attr & EFI_MEMORY_WB ? "WB" : "",
861 attr & EFI_MEMORY_WT ? "WT" : "",
862 attr & EFI_MEMORY_WC ? "WC" : "",
863 attr & EFI_MEMORY_UC ? "UC" : "");
864 return buf;
865 }
866
867 /*
868 * IA64 has a funky EFI memory map that doesn't work the same way as
869 * other architectures.
870 */
871 #ifndef CONFIG_IA64
872 /*
873 * efi_mem_attributes - lookup memmap attributes for physical address
874 * @phys_addr: the physical address to lookup
875 *
876 * Search in the EFI memory map for the region covering
877 * @phys_addr. Returns the EFI memory attributes if the region
878 * was found in the memory map, 0 otherwise.
879 */
efi_mem_attributes(unsigned long phys_addr)880 u64 efi_mem_attributes(unsigned long phys_addr)
881 {
882 efi_memory_desc_t *md;
883
884 if (!efi_enabled(EFI_MEMMAP))
885 return 0;
886
887 for_each_efi_memory_desc(md) {
888 if ((md->phys_addr <= phys_addr) &&
889 (phys_addr < (md->phys_addr +
890 (md->num_pages << EFI_PAGE_SHIFT))))
891 return md->attribute;
892 }
893 return 0;
894 }
895
896 /*
897 * efi_mem_type - lookup memmap type for physical address
898 * @phys_addr: the physical address to lookup
899 *
900 * Search in the EFI memory map for the region covering @phys_addr.
901 * Returns the EFI memory type if the region was found in the memory
902 * map, EFI_RESERVED_TYPE (zero) otherwise.
903 */
efi_mem_type(unsigned long phys_addr)904 int efi_mem_type(unsigned long phys_addr)
905 {
906 const efi_memory_desc_t *md;
907
908 if (!efi_enabled(EFI_MEMMAP))
909 return -ENOTSUPP;
910
911 for_each_efi_memory_desc(md) {
912 if ((md->phys_addr <= phys_addr) &&
913 (phys_addr < (md->phys_addr +
914 (md->num_pages << EFI_PAGE_SHIFT))))
915 return md->type;
916 }
917 return -EINVAL;
918 }
919 #endif
920
efi_status_to_err(efi_status_t status)921 int efi_status_to_err(efi_status_t status)
922 {
923 int err;
924
925 switch (status) {
926 case EFI_SUCCESS:
927 err = 0;
928 break;
929 case EFI_INVALID_PARAMETER:
930 err = -EINVAL;
931 break;
932 case EFI_OUT_OF_RESOURCES:
933 err = -ENOSPC;
934 break;
935 case EFI_DEVICE_ERROR:
936 err = -EIO;
937 break;
938 case EFI_WRITE_PROTECTED:
939 err = -EROFS;
940 break;
941 case EFI_SECURITY_VIOLATION:
942 err = -EACCES;
943 break;
944 case EFI_NOT_FOUND:
945 err = -ENOENT;
946 break;
947 case EFI_ABORTED:
948 err = -EINTR;
949 break;
950 default:
951 err = -EINVAL;
952 }
953
954 return err;
955 }
956
957 static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
958 static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
959
efi_memreserve_map_root(void)960 static int __init efi_memreserve_map_root(void)
961 {
962 if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
963 return -ENODEV;
964
965 efi_memreserve_root = memremap(efi.mem_reserve,
966 sizeof(*efi_memreserve_root),
967 MEMREMAP_WB);
968 if (WARN_ON_ONCE(!efi_memreserve_root))
969 return -ENOMEM;
970 return 0;
971 }
972
efi_mem_reserve_persistent(phys_addr_t addr,u64 size)973 int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
974 {
975 struct linux_efi_memreserve *rsv;
976 unsigned long prsv;
977 int rc, index;
978
979 if (efi_memreserve_root == (void *)ULONG_MAX)
980 return -ENODEV;
981
982 if (!efi_memreserve_root) {
983 rc = efi_memreserve_map_root();
984 if (rc)
985 return rc;
986 }
987
988 /* first try to find a slot in an existing linked list entry */
989 for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
990 rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
991 index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
992 if (index < rsv->size) {
993 rsv->entry[index].base = addr;
994 rsv->entry[index].size = size;
995
996 memunmap(rsv);
997 return 0;
998 }
999 memunmap(rsv);
1000 }
1001
1002 /* no slot found - allocate a new linked list entry */
1003 rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
1004 if (!rsv)
1005 return -ENOMEM;
1006
1007 /*
1008 * The memremap() call above assumes that a linux_efi_memreserve entry
1009 * never crosses a page boundary, so let's ensure that this remains true
1010 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
1011 * using SZ_4K explicitly in the size calculation below.
1012 */
1013 rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
1014 atomic_set(&rsv->count, 1);
1015 rsv->entry[0].base = addr;
1016 rsv->entry[0].size = size;
1017
1018 spin_lock(&efi_mem_reserve_persistent_lock);
1019 rsv->next = efi_memreserve_root->next;
1020 efi_memreserve_root->next = __pa(rsv);
1021 spin_unlock(&efi_mem_reserve_persistent_lock);
1022
1023 return 0;
1024 }
1025
efi_memreserve_root_init(void)1026 static int __init efi_memreserve_root_init(void)
1027 {
1028 if (efi_memreserve_root)
1029 return 0;
1030 if (efi_memreserve_map_root())
1031 efi_memreserve_root = (void *)ULONG_MAX;
1032 return 0;
1033 }
1034 early_initcall(efi_memreserve_root_init);
1035
1036 #ifdef CONFIG_KEXEC
update_efi_random_seed(struct notifier_block * nb,unsigned long code,void * unused)1037 static int update_efi_random_seed(struct notifier_block *nb,
1038 unsigned long code, void *unused)
1039 {
1040 struct linux_efi_random_seed *seed;
1041 u32 size = 0;
1042
1043 if (!kexec_in_progress)
1044 return NOTIFY_DONE;
1045
1046 seed = memremap(efi.rng_seed, sizeof(*seed), MEMREMAP_WB);
1047 if (seed != NULL) {
1048 size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1049 memunmap(seed);
1050 } else {
1051 pr_err("Could not map UEFI random seed!\n");
1052 }
1053 if (size > 0) {
1054 seed = memremap(efi.rng_seed, sizeof(*seed) + size,
1055 MEMREMAP_WB);
1056 if (seed != NULL) {
1057 seed->size = size;
1058 get_random_bytes(seed->bits, seed->size);
1059 memunmap(seed);
1060 } else {
1061 pr_err("Could not map UEFI random seed!\n");
1062 }
1063 }
1064 return NOTIFY_DONE;
1065 }
1066
1067 static struct notifier_block efi_random_seed_nb = {
1068 .notifier_call = update_efi_random_seed,
1069 };
1070
register_update_efi_random_seed(void)1071 static int register_update_efi_random_seed(void)
1072 {
1073 if (efi.rng_seed == EFI_INVALID_TABLE_ADDR)
1074 return 0;
1075 return register_reboot_notifier(&efi_random_seed_nb);
1076 }
1077 late_initcall(register_update_efi_random_seed);
1078 #endif
1079
