2 * Common EFI (Extensible Firmware Interface) support functions
3 * Based on Extensible Firmware Interface Specification version 1.0
5 * Copyright (C) 1999 VA Linux Systems
6 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
7 * Copyright (C) 1999-2002 Hewlett-Packard Co.
8 * David Mosberger-Tang <davidm@hpl.hp.com>
9 * Stephane Eranian <eranian@hpl.hp.com>
10 * Copyright (C) 2005-2008 Intel Co.
11 * Fenghua Yu <fenghua.yu@intel.com>
12 * Bibo Mao <bibo.mao@intel.com>
13 * Chandramouli Narayanan <mouli@linux.intel.com>
14 * Huang Ying <ying.huang@intel.com>
15 * Copyright (C) 2013 SuSE Labs
16 * Borislav Petkov <bp@suse.de> - runtime services VA mapping
18 * Copied from efi_32.c to eliminate the duplicated code between EFI
19 * 32/64 support code. --ying 2007-10-26
21 * All EFI Runtime Services are not implemented yet as EFI only
22 * supports physical mode addressing on SoftSDV. This is to be fixed
23 * in a future version. --drummond 1999-07-20
25 * Implemented EFI runtime services and virtual mode calls. --davidm
27 * Goutham Rao: <goutham.rao@intel.com>
28 * Skip non-WB memory and ignore empty memory ranges.
31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33 #include <linux/kernel.h>
34 #include <linux/init.h>
35 #include <linux/efi.h>
36 #include <linux/efi-bgrt.h>
37 #include <linux/export.h>
38 #include <linux/bootmem.h>
39 #include <linux/slab.h>
40 #include <linux/memblock.h>
41 #include <linux/spinlock.h>
42 #include <linux/uaccess.h>
43 #include <linux/time.h>
45 #include <linux/reboot.h>
46 #include <linux/bcd.h>
48 #include <asm/setup.h>
51 #include <asm/cacheflush.h>
52 #include <asm/tlbflush.h>
53 #include <asm/x86_init.h>
55 #include <asm/uv/uv.h>
59 #define EFI_MIN_RESERVE 5120
61 #define EFI_DUMMY_GUID \
62 EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
64 static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
66 struct efi_memory_map memmap;
68 static struct efi efi_phys __initdata;
69 static efi_system_table_t efi_systab __initdata;
71 unsigned long x86_efi_facility;
73 static __initdata efi_config_table_type_t arch_tables[] = {
75 {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab},
77 {NULL_GUID, NULL, NULL},
80 u64 efi_setup; /* efi setup_data physical address */
83 * Returns 1 if 'facility' is enabled, 0 otherwise.
85 int efi_enabled(int facility)
87 return test_bit(facility, &x86_efi_facility) != 0;
89 EXPORT_SYMBOL(efi_enabled);
91 static bool __initdata disable_runtime = false;
92 static int __init setup_noefi(char *arg)
94 disable_runtime = true;
97 early_param("noefi", setup_noefi);
100 EXPORT_SYMBOL(add_efi_memmap);
102 static int __init setup_add_efi_memmap(char *arg)
107 early_param("add_efi_memmap", setup_add_efi_memmap);
109 static bool efi_no_storage_paranoia;
111 static int __init setup_storage_paranoia(char *arg)
113 efi_no_storage_paranoia = true;
116 early_param("efi_no_storage_paranoia", setup_storage_paranoia);
118 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
123 spin_lock_irqsave(&rtc_lock, flags);
124 status = efi_call_virt2(get_time, tm, tc);
125 spin_unlock_irqrestore(&rtc_lock, flags);
129 static efi_status_t virt_efi_set_time(efi_time_t *tm)
134 spin_lock_irqsave(&rtc_lock, flags);
135 status = efi_call_virt1(set_time, tm);
136 spin_unlock_irqrestore(&rtc_lock, flags);
140 static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
147 spin_lock_irqsave(&rtc_lock, flags);
148 status = efi_call_virt3(get_wakeup_time,
149 enabled, pending, tm);
150 spin_unlock_irqrestore(&rtc_lock, flags);
154 static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
159 spin_lock_irqsave(&rtc_lock, flags);
160 status = efi_call_virt2(set_wakeup_time,
162 spin_unlock_irqrestore(&rtc_lock, flags);
166 static efi_status_t virt_efi_get_variable(efi_char16_t *name,
169 unsigned long *data_size,
172 return efi_call_virt5(get_variable,
177 static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
181 return efi_call_virt3(get_next_variable,
182 name_size, name, vendor);
185 static efi_status_t virt_efi_set_variable(efi_char16_t *name,
188 unsigned long data_size,
191 return efi_call_virt5(set_variable,
196 static efi_status_t virt_efi_query_variable_info(u32 attr,
198 u64 *remaining_space,
199 u64 *max_variable_size)
201 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
202 return EFI_UNSUPPORTED;
204 return efi_call_virt4(query_variable_info, attr, storage_space,
205 remaining_space, max_variable_size);
208 static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
210 return efi_call_virt1(get_next_high_mono_count, count);
213 static void virt_efi_reset_system(int reset_type,
215 unsigned long data_size,
218 efi_call_virt4(reset_system, reset_type, status,
222 static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
224 unsigned long sg_list)
226 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
227 return EFI_UNSUPPORTED;
229 return efi_call_virt3(update_capsule, capsules, count, sg_list);
232 static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
237 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
238 return EFI_UNSUPPORTED;
240 return efi_call_virt4(query_capsule_caps, capsules, count, max_size,
244 static efi_status_t __init phys_efi_set_virtual_address_map(
245 unsigned long memory_map_size,
246 unsigned long descriptor_size,
247 u32 descriptor_version,
248 efi_memory_desc_t *virtual_map)
252 efi_call_phys_prelog();
253 status = efi_call_phys4(efi_phys.set_virtual_address_map,
254 memory_map_size, descriptor_size,
255 descriptor_version, virtual_map);
256 efi_call_phys_epilog();
260 static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
266 spin_lock_irqsave(&rtc_lock, flags);
267 efi_call_phys_prelog();
268 status = efi_call_phys2(efi_phys.get_time, virt_to_phys(tm),
270 efi_call_phys_epilog();
271 spin_unlock_irqrestore(&rtc_lock, flags);
275 int efi_set_rtc_mmss(const struct timespec *now)
277 unsigned long nowtime = now->tv_sec;
283 status = efi.get_time(&eft, &cap);
284 if (status != EFI_SUCCESS) {
285 pr_err("Oops: efitime: can't read time!\n");
289 rtc_time_to_tm(nowtime, &tm);
290 if (!rtc_valid_tm(&tm)) {
291 eft.year = tm.tm_year + 1900;
292 eft.month = tm.tm_mon + 1;
293 eft.day = tm.tm_mday;
294 eft.minute = tm.tm_min;
295 eft.second = tm.tm_sec;
299 "%s: Invalid EFI RTC value: write of %lx to EFI RTC failed\n",
300 __FUNCTION__, nowtime);
304 status = efi.set_time(&eft);
305 if (status != EFI_SUCCESS) {
306 pr_err("Oops: efitime: can't write time!\n");
312 void efi_get_time(struct timespec *now)
318 status = efi.get_time(&eft, &cap);
319 if (status != EFI_SUCCESS)
320 pr_err("Oops: efitime: can't read time!\n");
322 now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour,
323 eft.minute, eft.second);
328 * Tell the kernel about the EFI memory map. This might include
329 * more than the max 128 entries that can fit in the e820 legacy
330 * (zeropage) memory map.
333 static void __init do_add_efi_memmap(void)
337 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
338 efi_memory_desc_t *md = p;
339 unsigned long long start = md->phys_addr;
340 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
344 case EFI_LOADER_CODE:
345 case EFI_LOADER_DATA:
346 case EFI_BOOT_SERVICES_CODE:
347 case EFI_BOOT_SERVICES_DATA:
348 case EFI_CONVENTIONAL_MEMORY:
349 if (md->attribute & EFI_MEMORY_WB)
350 e820_type = E820_RAM;
352 e820_type = E820_RESERVED;
354 case EFI_ACPI_RECLAIM_MEMORY:
355 e820_type = E820_ACPI;
357 case EFI_ACPI_MEMORY_NVS:
358 e820_type = E820_NVS;
360 case EFI_UNUSABLE_MEMORY:
361 e820_type = E820_UNUSABLE;
365 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
366 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
367 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
369 e820_type = E820_RESERVED;
372 e820_add_region(start, size, e820_type);
374 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
377 int __init efi_memblock_x86_reserve_range(void)
379 struct efi_info *e = &boot_params.efi_info;
383 /* Can't handle data above 4GB at this time */
384 if (e->efi_memmap_hi) {
385 pr_err("Memory map is above 4GB, disabling EFI.\n");
388 pmap = e->efi_memmap;
390 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
392 memmap.phys_map = (void *)pmap;
393 memmap.nr_map = e->efi_memmap_size /
395 memmap.desc_size = e->efi_memdesc_size;
396 memmap.desc_version = e->efi_memdesc_version;
398 memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
400 efi.memmap = &memmap;
405 static void __init print_efi_memmap(void)
408 efi_memory_desc_t *md;
412 for (p = memmap.map, i = 0;
414 p += memmap.desc_size, i++) {
416 pr_info("mem%02u: type=%u, attr=0x%llx, "
417 "range=[0x%016llx-0x%016llx) (%lluMB)\n",
418 i, md->type, md->attribute, md->phys_addr,
419 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
420 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
422 #endif /* EFI_DEBUG */
425 void __init efi_reserve_boot_services(void)
429 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
430 efi_memory_desc_t *md = p;
431 u64 start = md->phys_addr;
432 u64 size = md->num_pages << EFI_PAGE_SHIFT;
434 if (md->type != EFI_BOOT_SERVICES_CODE &&
435 md->type != EFI_BOOT_SERVICES_DATA)
437 /* Only reserve where possible:
438 * - Not within any already allocated areas
439 * - Not over any memory area (really needed, if above?)
440 * - Not within any part of the kernel
441 * - Not the bios reserved area
443 if ((start + size > __pa_symbol(_text)
444 && start <= __pa_symbol(_end)) ||
445 !e820_all_mapped(start, start+size, E820_RAM) ||
446 memblock_is_region_reserved(start, size)) {
447 /* Could not reserve, skip it */
449 memblock_dbg("Could not reserve boot range "
450 "[0x%010llx-0x%010llx]\n",
451 start, start+size-1);
453 memblock_reserve(start, size);
457 void __init efi_unmap_memmap(void)
459 clear_bit(EFI_MEMMAP, &x86_efi_facility);
461 early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
466 void __init efi_free_boot_services(void)
470 if (!efi_is_native())
473 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
474 efi_memory_desc_t *md = p;
475 unsigned long long start = md->phys_addr;
476 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
478 if (md->type != EFI_BOOT_SERVICES_CODE &&
479 md->type != EFI_BOOT_SERVICES_DATA)
482 /* Could not reserve boot area */
486 free_bootmem_late(start, size);
492 static int __init efi_systab_init(void *phys)
494 if (efi_enabled(EFI_64BIT)) {
495 efi_system_table_64_t *systab64;
496 struct efi_setup_data *data = NULL;
500 data = early_memremap(efi_setup, sizeof(*data));
504 systab64 = early_ioremap((unsigned long)phys,
506 if (systab64 == NULL) {
507 pr_err("Couldn't map the system table!\n");
509 early_iounmap(data, sizeof(*data));
513 efi_systab.hdr = systab64->hdr;
514 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
516 tmp |= data ? data->fw_vendor : systab64->fw_vendor;
517 efi_systab.fw_revision = systab64->fw_revision;
518 efi_systab.con_in_handle = systab64->con_in_handle;
519 tmp |= systab64->con_in_handle;
520 efi_systab.con_in = systab64->con_in;
521 tmp |= systab64->con_in;
522 efi_systab.con_out_handle = systab64->con_out_handle;
523 tmp |= systab64->con_out_handle;
524 efi_systab.con_out = systab64->con_out;
525 tmp |= systab64->con_out;
526 efi_systab.stderr_handle = systab64->stderr_handle;
527 tmp |= systab64->stderr_handle;
528 efi_systab.stderr = systab64->stderr;
529 tmp |= systab64->stderr;
530 efi_systab.runtime = data ?
531 (void *)(unsigned long)data->runtime :
532 (void *)(unsigned long)systab64->runtime;
533 tmp |= data ? data->runtime : systab64->runtime;
534 efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
535 tmp |= systab64->boottime;
536 efi_systab.nr_tables = systab64->nr_tables;
537 efi_systab.tables = data ? (unsigned long)data->tables :
539 tmp |= data ? data->tables : systab64->tables;
541 early_iounmap(systab64, sizeof(*systab64));
543 early_iounmap(data, sizeof(*data));
546 pr_err("EFI data located above 4GB, disabling EFI.\n");
551 efi_system_table_32_t *systab32;
553 systab32 = early_ioremap((unsigned long)phys,
555 if (systab32 == NULL) {
556 pr_err("Couldn't map the system table!\n");
560 efi_systab.hdr = systab32->hdr;
561 efi_systab.fw_vendor = systab32->fw_vendor;
562 efi_systab.fw_revision = systab32->fw_revision;
563 efi_systab.con_in_handle = systab32->con_in_handle;
564 efi_systab.con_in = systab32->con_in;
565 efi_systab.con_out_handle = systab32->con_out_handle;
566 efi_systab.con_out = systab32->con_out;
567 efi_systab.stderr_handle = systab32->stderr_handle;
568 efi_systab.stderr = systab32->stderr;
569 efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
570 efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
571 efi_systab.nr_tables = systab32->nr_tables;
572 efi_systab.tables = systab32->tables;
574 early_iounmap(systab32, sizeof(*systab32));
577 efi.systab = &efi_systab;
580 * Verify the EFI Table
582 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
583 pr_err("System table signature incorrect!\n");
586 if ((efi.systab->hdr.revision >> 16) == 0)
587 pr_err("Warning: System table version "
588 "%d.%02d, expected 1.00 or greater!\n",
589 efi.systab->hdr.revision >> 16,
590 efi.systab->hdr.revision & 0xffff);
595 static int __init efi_runtime_init(void)
597 efi_runtime_services_t *runtime;
600 * Check out the runtime services table. We need to map
601 * the runtime services table so that we can grab the physical
602 * address of several of the EFI runtime functions, needed to
603 * set the firmware into virtual mode.
605 runtime = early_ioremap((unsigned long)efi.systab->runtime,
606 sizeof(efi_runtime_services_t));
608 pr_err("Could not map the runtime service table!\n");
612 * We will only need *early* access to the following
613 * two EFI runtime services before set_virtual_address_map
616 efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
617 efi_phys.set_virtual_address_map =
618 (efi_set_virtual_address_map_t *)
619 runtime->set_virtual_address_map;
621 * Make efi_get_time can be called before entering
624 efi.get_time = phys_efi_get_time;
625 early_iounmap(runtime, sizeof(efi_runtime_services_t));
630 static int __init efi_memmap_init(void)
632 /* Map the EFI memory map */
633 memmap.map = early_ioremap((unsigned long)memmap.phys_map,
634 memmap.nr_map * memmap.desc_size);
635 if (memmap.map == NULL) {
636 pr_err("Could not map the memory map!\n");
639 memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
648 * A number of config table entries get remapped to virtual addresses
649 * after entering EFI virtual mode. However, the kexec kernel requires
650 * their physical addresses therefore we pass them via setup_data and
651 * correct those entries to their respective physical addresses here.
653 * Currently only handles smbios which is necessary for some firmware
656 static int __init efi_reuse_config(u64 tables, int nr_tables)
660 struct efi_setup_data *data;
665 if (!efi_enabled(EFI_64BIT))
668 data = early_memremap(efi_setup, sizeof(*data));
677 sz = sizeof(efi_config_table_64_t);
679 p = tablep = early_memremap(tables, nr_tables * sz);
681 pr_err("Could not map Configuration table!\n");
686 for (i = 0; i < efi.systab->nr_tables; i++) {
689 guid = ((efi_config_table_64_t *)p)->guid;
691 if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
692 ((efi_config_table_64_t *)p)->table = data->smbios;
695 early_iounmap(tablep, nr_tables * sz);
698 early_iounmap(data, sizeof(*data));
703 void __init efi_init(void)
706 char vendor[100] = "unknown";
711 if (boot_params.efi_info.efi_systab_hi ||
712 boot_params.efi_info.efi_memmap_hi) {
713 pr_info("Table located above 4GB, disabling EFI.\n");
716 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
718 efi_phys.systab = (efi_system_table_t *)
719 (boot_params.efi_info.efi_systab |
720 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
723 if (efi_systab_init(efi_phys.systab))
726 set_bit(EFI_SYSTEM_TABLES, &x86_efi_facility);
728 efi.config_table = (unsigned long)efi.systab->tables;
729 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor;
730 efi.runtime = (unsigned long)efi.systab->runtime;
733 * Show what we know for posterity
735 c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
737 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
741 pr_err("Could not map the firmware vendor!\n");
742 early_iounmap(tmp, 2);
744 pr_info("EFI v%u.%.02u by %s\n",
745 efi.systab->hdr.revision >> 16,
746 efi.systab->hdr.revision & 0xffff, vendor);
748 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
751 if (efi_config_init(arch_tables))
754 set_bit(EFI_CONFIG_TABLES, &x86_efi_facility);
757 * Note: We currently don't support runtime services on an EFI
758 * that doesn't match the kernel 32/64-bit mode.
761 if (!efi_is_native())
762 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
764 if (disable_runtime || efi_runtime_init())
766 set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
768 if (efi_memmap_init())
771 set_bit(EFI_MEMMAP, &x86_efi_facility);
776 void __init efi_late_init(void)
781 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
785 addr = md->virt_addr;
786 npages = md->num_pages;
788 memrange_efi_to_native(&addr, &npages);
791 set_memory_x(addr, npages);
793 set_memory_nx(addr, npages);
796 void __init runtime_code_page_mkexec(void)
798 efi_memory_desc_t *md;
801 /* Make EFI runtime service code area executable */
802 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
805 if (md->type != EFI_RUNTIME_SERVICES_CODE)
808 efi_set_executable(md, true);
812 void efi_memory_uc(u64 addr, unsigned long size)
814 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
817 npages = round_up(size, page_shift) / page_shift;
818 memrange_efi_to_native(&addr, &npages);
819 set_memory_uc(addr, npages);
822 void __init old_map_region(efi_memory_desc_t *md)
824 u64 start_pfn, end_pfn, end;
828 start_pfn = PFN_DOWN(md->phys_addr);
829 size = md->num_pages << PAGE_SHIFT;
830 end = md->phys_addr + size;
831 end_pfn = PFN_UP(end);
833 if (pfn_range_is_mapped(start_pfn, end_pfn)) {
834 va = __va(md->phys_addr);
836 if (!(md->attribute & EFI_MEMORY_WB))
837 efi_memory_uc((u64)(unsigned long)va, size);
839 va = efi_ioremap(md->phys_addr, size,
840 md->type, md->attribute);
842 md->virt_addr = (u64) (unsigned long) va;
844 pr_err("ioremap of 0x%llX failed!\n",
845 (unsigned long long)md->phys_addr);
848 /* Merge contiguous regions of the same type and attribute */
849 static void __init efi_merge_regions(void)
852 efi_memory_desc_t *md, *prev_md = NULL;
854 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
863 if (prev_md->type != md->type ||
864 prev_md->attribute != md->attribute) {
869 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
871 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
872 prev_md->num_pages += md->num_pages;
873 md->type = EFI_RESERVED_TYPE;
881 static void __init get_systab_virt_addr(efi_memory_desc_t *md)
886 size = md->num_pages << EFI_PAGE_SHIFT;
887 end = md->phys_addr + size;
888 systab = (u64)(unsigned long)efi_phys.systab;
889 if (md->phys_addr <= systab && systab < end) {
890 systab += md->virt_addr - md->phys_addr;
891 efi.systab = (efi_system_table_t *)(unsigned long)systab;
895 static int __init save_runtime_map(void)
897 efi_memory_desc_t *md;
898 void *tmp, *p, *q = NULL;
901 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
904 if (!(md->attribute & EFI_MEMORY_RUNTIME) ||
905 (md->type == EFI_BOOT_SERVICES_CODE) ||
906 (md->type == EFI_BOOT_SERVICES_DATA))
908 tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL);
913 memcpy(q + count * memmap.desc_size, md, memmap.desc_size);
917 efi_runtime_map_setup(q, count, memmap.desc_size);
926 * Map efi regions which were passed via setup_data. The virt_addr is a fixed
927 * addr which was used in first kernel of a kexec boot.
929 static void __init efi_map_regions_fixed(void)
932 efi_memory_desc_t *md;
934 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
936 efi_map_region_fixed(md); /* FIXME: add error handling */
937 get_systab_virt_addr(md);
943 * Map efi memory ranges for runtime serivce and update new_memmap with virtual
946 static void * __init efi_map_regions(int *count)
948 efi_memory_desc_t *md;
949 void *p, *tmp, *new_memmap = NULL;
951 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
953 if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
955 if (md->type != EFI_BOOT_SERVICES_CODE &&
956 md->type != EFI_BOOT_SERVICES_DATA)
962 get_systab_virt_addr(md);
964 tmp = krealloc(new_memmap, (*count + 1) * memmap.desc_size,
969 memcpy(new_memmap + (*count * memmap.desc_size), md,
981 * This function will switch the EFI runtime services to virtual mode.
982 * Essentially, we look through the EFI memmap and map every region that
983 * has the runtime attribute bit set in its memory descriptor into the
984 * ->trampoline_pgd page table using a top-down VA allocation scheme.
986 * The old method which used to update that memory descriptor with the
987 * virtual address obtained from ioremap() is still supported when the
988 * kernel is booted with efi=old_map on its command line. Same old
989 * method enabled the runtime services to be called without having to
990 * thunk back into physical mode for every invocation.
992 * The new method does a pagetable switch in a preemption-safe manner
993 * so that we're in a different address space when calling a runtime
994 * function. For function arguments passing we do copy the PGDs of the
995 * kernel page table into ->trampoline_pgd prior to each call.
997 * Specially for kexec boot, efi runtime maps in previous kernel should
998 * be passed in via setup_data. In that case runtime ranges will be mapped
999 * to the same virtual addresses as the first kernel.
1001 void __init efi_enter_virtual_mode(void)
1003 efi_status_t status;
1004 void *new_memmap = NULL;
1010 * We don't do virtual mode, since we don't do runtime services, on
1013 if (!efi_is_native()) {
1019 efi_map_regions_fixed();
1021 efi_merge_regions();
1022 new_memmap = efi_map_regions(&count);
1024 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
1029 err = save_runtime_map();
1031 pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
1033 BUG_ON(!efi.systab);
1035 efi_setup_page_tables();
1036 efi_sync_low_kernel_mappings();
1039 status = phys_efi_set_virtual_address_map(
1040 memmap.desc_size * count,
1042 memmap.desc_version,
1043 (efi_memory_desc_t *)__pa(new_memmap));
1045 if (status != EFI_SUCCESS) {
1046 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
1048 panic("EFI call to SetVirtualAddressMap() failed!");
1053 * Now that EFI is in virtual mode, update the function
1054 * pointers in the runtime service table to the new virtual addresses.
1056 * Call EFI services through wrapper functions.
1058 efi.runtime_version = efi_systab.hdr.revision;
1059 efi.get_time = virt_efi_get_time;
1060 efi.set_time = virt_efi_set_time;
1061 efi.get_wakeup_time = virt_efi_get_wakeup_time;
1062 efi.set_wakeup_time = virt_efi_set_wakeup_time;
1063 efi.get_variable = virt_efi_get_variable;
1064 efi.get_next_variable = virt_efi_get_next_variable;
1065 efi.set_variable = virt_efi_set_variable;
1066 efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
1067 efi.reset_system = virt_efi_reset_system;
1068 efi.set_virtual_address_map = NULL;
1069 efi.query_variable_info = virt_efi_query_variable_info;
1070 efi.update_capsule = virt_efi_update_capsule;
1071 efi.query_capsule_caps = virt_efi_query_capsule_caps;
1073 efi_runtime_mkexec();
1077 /* clean DUMMY object */
1078 efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
1079 EFI_VARIABLE_NON_VOLATILE |
1080 EFI_VARIABLE_BOOTSERVICE_ACCESS |
1081 EFI_VARIABLE_RUNTIME_ACCESS,
1086 * Convenience functions to obtain memory types and attributes
1088 u32 efi_mem_type(unsigned long phys_addr)
1090 efi_memory_desc_t *md;
1093 if (!efi_enabled(EFI_MEMMAP))
1096 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1098 if ((md->phys_addr <= phys_addr) &&
1099 (phys_addr < (md->phys_addr +
1100 (md->num_pages << EFI_PAGE_SHIFT))))
1106 u64 efi_mem_attributes(unsigned long phys_addr)
1108 efi_memory_desc_t *md;
1111 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1113 if ((md->phys_addr <= phys_addr) &&
1114 (phys_addr < (md->phys_addr +
1115 (md->num_pages << EFI_PAGE_SHIFT))))
1116 return md->attribute;
1122 * Some firmware has serious problems when using more than 50% of the EFI
1123 * variable store, i.e. it triggers bugs that can brick machines. Ensure that
1124 * we never use more than this safe limit.
1126 * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
1129 efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
1131 efi_status_t status;
1132 u64 storage_size, remaining_size, max_size;
1134 if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
1137 status = efi.query_variable_info(attributes, &storage_size,
1138 &remaining_size, &max_size);
1139 if (status != EFI_SUCCESS)
1143 * Some firmware implementations refuse to boot if there's insufficient
1144 * space in the variable store. We account for that by refusing the
1145 * write if permitting it would reduce the available space to under
1146 * 5KB. This figure was provided by Samsung, so should be safe.
1148 if ((remaining_size - size < EFI_MIN_RESERVE) &&
1149 !efi_no_storage_paranoia) {
1152 * Triggering garbage collection may require that the firmware
1153 * generate a real EFI_OUT_OF_RESOURCES error. We can force
1154 * that by attempting to use more space than is available.
1156 unsigned long dummy_size = remaining_size + 1024;
1157 void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
1160 return EFI_OUT_OF_RESOURCES;
1162 status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
1163 EFI_VARIABLE_NON_VOLATILE |
1164 EFI_VARIABLE_BOOTSERVICE_ACCESS |
1165 EFI_VARIABLE_RUNTIME_ACCESS,
1168 if (status == EFI_SUCCESS) {
1170 * This should have failed, so if it didn't make sure
1171 * that we delete it...
1173 efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
1174 EFI_VARIABLE_NON_VOLATILE |
1175 EFI_VARIABLE_BOOTSERVICE_ACCESS |
1176 EFI_VARIABLE_RUNTIME_ACCESS,
1183 * The runtime code may now have triggered a garbage collection
1184 * run, so check the variable info again
1186 status = efi.query_variable_info(attributes, &storage_size,
1187 &remaining_size, &max_size);
1189 if (status != EFI_SUCCESS)
1193 * There still isn't enough room, so return an error
1195 if (remaining_size - size < EFI_MIN_RESERVE)
1196 return EFI_OUT_OF_RESOURCES;
1201 EXPORT_SYMBOL_GPL(efi_query_variable_store);
1203 static int __init parse_efi_cmdline(char *str)
1208 if (!strncmp(str, "old_map", 7))
1209 set_bit(EFI_OLD_MEMMAP, &x86_efi_facility);
1213 early_param("efi", parse_efi_cmdline);
1215 void __init efi_apply_memmap_quirks(void)
1218 * Once setup is done earlier, unmap the EFI memory map on mismatched
1219 * firmware/kernel architectures since there is no support for runtime
1222 if (!efi_is_native()) {
1223 pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
1228 * UV doesn't support the new EFI pagetable mapping yet.
1231 set_bit(EFI_OLD_MEMMAP, &x86_efi_facility);