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>
16 * Copied from efi_32.c to eliminate the duplicated code between EFI
17 * 32/64 support code. --ying 2007-10-26
19 * All EFI Runtime Services are not implemented yet as EFI only
20 * supports physical mode addressing on SoftSDV. This is to be fixed
21 * in a future version. --drummond 1999-07-20
23 * Implemented EFI runtime services and virtual mode calls. --davidm
25 * Goutham Rao: <goutham.rao@intel.com>
26 * Skip non-WB memory and ignore empty memory ranges.
29 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31 #include <linux/kernel.h>
32 #include <linux/init.h>
33 #include <linux/efi.h>
34 #include <linux/efi-bgrt.h>
35 #include <linux/export.h>
36 #include <linux/bootmem.h>
37 #include <linux/slab.h>
38 #include <linux/memblock.h>
39 #include <linux/spinlock.h>
40 #include <linux/uaccess.h>
41 #include <linux/time.h>
43 #include <linux/reboot.h>
44 #include <linux/bcd.h>
45 #include <linux/ucs2_string.h>
47 #include <asm/setup.h>
50 #include <asm/cacheflush.h>
51 #include <asm/tlbflush.h>
52 #include <asm/x86_init.h>
58 * There's some additional metadata associated with each
59 * variable. Intel's reference implementation is 60 bytes - bump that
60 * to account for potential alignment constraints
62 #define VAR_METADATA_SIZE 64
64 struct efi __read_mostly efi = {
65 .mps = EFI_INVALID_TABLE_ADDR,
66 .acpi = EFI_INVALID_TABLE_ADDR,
67 .acpi20 = EFI_INVALID_TABLE_ADDR,
68 .smbios = EFI_INVALID_TABLE_ADDR,
69 .sal_systab = EFI_INVALID_TABLE_ADDR,
70 .boot_info = EFI_INVALID_TABLE_ADDR,
71 .hcdp = EFI_INVALID_TABLE_ADDR,
72 .uga = EFI_INVALID_TABLE_ADDR,
73 .uv_systab = EFI_INVALID_TABLE_ADDR,
77 struct efi_memory_map memmap;
79 static struct efi efi_phys __initdata;
80 static efi_system_table_t efi_systab __initdata;
82 static u64 efi_var_store_size;
83 static u64 efi_var_remaining_size;
84 static u64 efi_var_max_var_size;
85 static u64 boot_used_size;
86 static u64 boot_var_size;
87 static u64 active_size;
89 unsigned long x86_efi_facility;
92 * Returns 1 if 'facility' is enabled, 0 otherwise.
94 int efi_enabled(int facility)
96 return test_bit(facility, &x86_efi_facility) != 0;
98 EXPORT_SYMBOL(efi_enabled);
100 static bool __initdata disable_runtime = false;
101 static int __init setup_noefi(char *arg)
103 disable_runtime = true;
106 early_param("noefi", setup_noefi);
109 EXPORT_SYMBOL(add_efi_memmap);
111 static int __init setup_add_efi_memmap(char *arg)
116 early_param("add_efi_memmap", setup_add_efi_memmap);
118 static bool efi_no_storage_paranoia;
120 static int __init setup_storage_paranoia(char *arg)
122 efi_no_storage_paranoia = true;
125 early_param("efi_no_storage_paranoia", setup_storage_paranoia);
128 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
133 spin_lock_irqsave(&rtc_lock, flags);
134 status = efi_call_virt2(get_time, tm, tc);
135 spin_unlock_irqrestore(&rtc_lock, flags);
139 static efi_status_t virt_efi_set_time(efi_time_t *tm)
144 spin_lock_irqsave(&rtc_lock, flags);
145 status = efi_call_virt1(set_time, tm);
146 spin_unlock_irqrestore(&rtc_lock, flags);
150 static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
157 spin_lock_irqsave(&rtc_lock, flags);
158 status = efi_call_virt3(get_wakeup_time,
159 enabled, pending, tm);
160 spin_unlock_irqrestore(&rtc_lock, flags);
164 static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
169 spin_lock_irqsave(&rtc_lock, flags);
170 status = efi_call_virt2(set_wakeup_time,
172 spin_unlock_irqrestore(&rtc_lock, flags);
176 static efi_status_t virt_efi_get_variable(efi_char16_t *name,
179 unsigned long *data_size,
182 return efi_call_virt5(get_variable,
187 static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
192 static bool finished = false;
195 status = efi_call_virt3(get_next_variable,
196 name_size, name, vendor);
198 if (status == EFI_NOT_FOUND) {
200 if (var_size < boot_used_size) {
201 boot_var_size = boot_used_size - var_size;
202 active_size += boot_var_size;
204 printk(KERN_WARNING FW_BUG "efi: Inconsistent initial sizes\n");
208 if (boot_used_size && !finished) {
214 s = virt_efi_get_variable(name, vendor, &attr, &size, NULL);
216 if (s != EFI_BUFFER_TOO_SMALL || !size)
219 tmp = kmalloc(size, GFP_ATOMIC);
224 s = virt_efi_get_variable(name, vendor, &attr, &size, tmp);
226 if (s == EFI_SUCCESS && (attr & EFI_VARIABLE_NON_VOLATILE)) {
228 var_size += ucs2_strsize(name, 1024);
230 active_size += VAR_METADATA_SIZE;
231 active_size += ucs2_strsize(name, 1024);
240 static efi_status_t virt_efi_set_variable(efi_char16_t *name,
243 unsigned long data_size,
248 unsigned long orig_size = 0;
250 status = virt_efi_get_variable(name, vendor, &orig_attr, &orig_size,
253 if (status != EFI_BUFFER_TOO_SMALL)
256 status = efi_call_virt5(set_variable,
260 if (status == EFI_SUCCESS) {
262 active_size -= orig_size;
263 active_size -= ucs2_strsize(name, 1024);
264 active_size -= VAR_METADATA_SIZE;
267 active_size += data_size;
268 active_size += ucs2_strsize(name, 1024);
269 active_size += VAR_METADATA_SIZE;
276 static efi_status_t virt_efi_query_variable_info(u32 attr,
278 u64 *remaining_space,
279 u64 *max_variable_size)
281 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
282 return EFI_UNSUPPORTED;
284 return efi_call_virt4(query_variable_info, attr, storage_space,
285 remaining_space, max_variable_size);
288 static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
290 return efi_call_virt1(get_next_high_mono_count, count);
293 static void virt_efi_reset_system(int reset_type,
295 unsigned long data_size,
298 efi_call_virt4(reset_system, reset_type, status,
302 static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
304 unsigned long sg_list)
306 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
307 return EFI_UNSUPPORTED;
309 return efi_call_virt3(update_capsule, capsules, count, sg_list);
312 static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
317 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
318 return EFI_UNSUPPORTED;
320 return efi_call_virt4(query_capsule_caps, capsules, count, max_size,
324 static efi_status_t __init phys_efi_set_virtual_address_map(
325 unsigned long memory_map_size,
326 unsigned long descriptor_size,
327 u32 descriptor_version,
328 efi_memory_desc_t *virtual_map)
332 efi_call_phys_prelog();
333 status = efi_call_phys4(efi_phys.set_virtual_address_map,
334 memory_map_size, descriptor_size,
335 descriptor_version, virtual_map);
336 efi_call_phys_epilog();
340 static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
346 spin_lock_irqsave(&rtc_lock, flags);
347 efi_call_phys_prelog();
348 status = efi_call_phys2(efi_phys.get_time, virt_to_phys(tm),
350 efi_call_phys_epilog();
351 spin_unlock_irqrestore(&rtc_lock, flags);
355 int efi_set_rtc_mmss(unsigned long nowtime)
362 status = efi.get_time(&eft, &cap);
363 if (status != EFI_SUCCESS) {
364 pr_err("Oops: efitime: can't read time!\n");
368 rtc_time_to_tm(nowtime, &tm);
369 if (!rtc_valid_tm(&tm)) {
370 eft.year = tm.tm_year + 1900;
371 eft.month = tm.tm_mon + 1;
372 eft.day = tm.tm_mday;
373 eft.minute = tm.tm_min;
374 eft.second = tm.tm_sec;
378 "%s: Invalid EFI RTC value: write of %lx to EFI RTC failed\n",
379 __FUNCTION__, nowtime);
383 status = efi.set_time(&eft);
384 if (status != EFI_SUCCESS) {
385 pr_err("Oops: efitime: can't write time!\n");
391 unsigned long efi_get_time(void)
397 status = efi.get_time(&eft, &cap);
398 if (status != EFI_SUCCESS)
399 pr_err("Oops: efitime: can't read time!\n");
401 return mktime(eft.year, eft.month, eft.day, eft.hour,
402 eft.minute, eft.second);
406 * Tell the kernel about the EFI memory map. This might include
407 * more than the max 128 entries that can fit in the e820 legacy
408 * (zeropage) memory map.
411 static void __init do_add_efi_memmap(void)
415 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
416 efi_memory_desc_t *md = p;
417 unsigned long long start = md->phys_addr;
418 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
422 case EFI_LOADER_CODE:
423 case EFI_LOADER_DATA:
424 case EFI_BOOT_SERVICES_CODE:
425 case EFI_BOOT_SERVICES_DATA:
426 case EFI_CONVENTIONAL_MEMORY:
427 if (md->attribute & EFI_MEMORY_WB)
428 e820_type = E820_RAM;
430 e820_type = E820_RESERVED;
432 case EFI_ACPI_RECLAIM_MEMORY:
433 e820_type = E820_ACPI;
435 case EFI_ACPI_MEMORY_NVS:
436 e820_type = E820_NVS;
438 case EFI_UNUSABLE_MEMORY:
439 e820_type = E820_UNUSABLE;
443 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
444 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
445 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
447 e820_type = E820_RESERVED;
450 e820_add_region(start, size, e820_type);
452 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
455 int __init efi_memblock_x86_reserve_range(void)
457 struct efi_info *e = &boot_params.efi_info;
461 /* Can't handle data above 4GB at this time */
462 if (e->efi_memmap_hi) {
463 pr_err("Memory map is above 4GB, disabling EFI.\n");
466 pmap = e->efi_memmap;
468 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
470 memmap.phys_map = (void *)pmap;
471 memmap.nr_map = e->efi_memmap_size /
473 memmap.desc_size = e->efi_memdesc_size;
474 memmap.desc_version = e->efi_memdesc_version;
476 memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
482 static void __init print_efi_memmap(void)
484 efi_memory_desc_t *md;
488 for (p = memmap.map, i = 0;
490 p += memmap.desc_size, i++) {
492 pr_info("mem%02u: type=%u, attr=0x%llx, "
493 "range=[0x%016llx-0x%016llx) (%lluMB)\n",
494 i, md->type, md->attribute, md->phys_addr,
495 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
496 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
499 #endif /* EFI_DEBUG */
501 void __init efi_reserve_boot_services(void)
505 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
506 efi_memory_desc_t *md = p;
507 u64 start = md->phys_addr;
508 u64 size = md->num_pages << EFI_PAGE_SHIFT;
510 if (md->type != EFI_BOOT_SERVICES_CODE &&
511 md->type != EFI_BOOT_SERVICES_DATA)
513 /* Only reserve where possible:
514 * - Not within any already allocated areas
515 * - Not over any memory area (really needed, if above?)
516 * - Not within any part of the kernel
517 * - Not the bios reserved area
519 if ((start+size >= __pa_symbol(_text)
520 && start <= __pa_symbol(_end)) ||
521 !e820_all_mapped(start, start+size, E820_RAM) ||
522 memblock_is_region_reserved(start, size)) {
523 /* Could not reserve, skip it */
525 memblock_dbg("Could not reserve boot range "
526 "[0x%010llx-0x%010llx]\n",
527 start, start+size-1);
529 memblock_reserve(start, size);
533 void __init efi_unmap_memmap(void)
535 clear_bit(EFI_MEMMAP, &x86_efi_facility);
537 early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
542 void __init efi_free_boot_services(void)
546 if (!efi_is_native())
549 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
550 efi_memory_desc_t *md = p;
551 unsigned long long start = md->phys_addr;
552 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
554 if (md->type != EFI_BOOT_SERVICES_CODE &&
555 md->type != EFI_BOOT_SERVICES_DATA)
558 /* Could not reserve boot area */
562 free_bootmem_late(start, size);
568 static int __init efi_systab_init(void *phys)
570 if (efi_enabled(EFI_64BIT)) {
571 efi_system_table_64_t *systab64;
574 systab64 = early_ioremap((unsigned long)phys,
576 if (systab64 == NULL) {
577 pr_err("Couldn't map the system table!\n");
581 efi_systab.hdr = systab64->hdr;
582 efi_systab.fw_vendor = systab64->fw_vendor;
583 tmp |= systab64->fw_vendor;
584 efi_systab.fw_revision = systab64->fw_revision;
585 efi_systab.con_in_handle = systab64->con_in_handle;
586 tmp |= systab64->con_in_handle;
587 efi_systab.con_in = systab64->con_in;
588 tmp |= systab64->con_in;
589 efi_systab.con_out_handle = systab64->con_out_handle;
590 tmp |= systab64->con_out_handle;
591 efi_systab.con_out = systab64->con_out;
592 tmp |= systab64->con_out;
593 efi_systab.stderr_handle = systab64->stderr_handle;
594 tmp |= systab64->stderr_handle;
595 efi_systab.stderr = systab64->stderr;
596 tmp |= systab64->stderr;
597 efi_systab.runtime = (void *)(unsigned long)systab64->runtime;
598 tmp |= systab64->runtime;
599 efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
600 tmp |= systab64->boottime;
601 efi_systab.nr_tables = systab64->nr_tables;
602 efi_systab.tables = systab64->tables;
603 tmp |= systab64->tables;
605 early_iounmap(systab64, sizeof(*systab64));
608 pr_err("EFI data located above 4GB, disabling EFI.\n");
613 efi_system_table_32_t *systab32;
615 systab32 = early_ioremap((unsigned long)phys,
617 if (systab32 == NULL) {
618 pr_err("Couldn't map the system table!\n");
622 efi_systab.hdr = systab32->hdr;
623 efi_systab.fw_vendor = systab32->fw_vendor;
624 efi_systab.fw_revision = systab32->fw_revision;
625 efi_systab.con_in_handle = systab32->con_in_handle;
626 efi_systab.con_in = systab32->con_in;
627 efi_systab.con_out_handle = systab32->con_out_handle;
628 efi_systab.con_out = systab32->con_out;
629 efi_systab.stderr_handle = systab32->stderr_handle;
630 efi_systab.stderr = systab32->stderr;
631 efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
632 efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
633 efi_systab.nr_tables = systab32->nr_tables;
634 efi_systab.tables = systab32->tables;
636 early_iounmap(systab32, sizeof(*systab32));
639 efi.systab = &efi_systab;
642 * Verify the EFI Table
644 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
645 pr_err("System table signature incorrect!\n");
648 if ((efi.systab->hdr.revision >> 16) == 0)
649 pr_err("Warning: System table version "
650 "%d.%02d, expected 1.00 or greater!\n",
651 efi.systab->hdr.revision >> 16,
652 efi.systab->hdr.revision & 0xffff);
657 static int __init efi_config_init(u64 tables, int nr_tables)
659 void *config_tables, *tablep;
662 if (efi_enabled(EFI_64BIT))
663 sz = sizeof(efi_config_table_64_t);
665 sz = sizeof(efi_config_table_32_t);
668 * Let's see what config tables the firmware passed to us.
670 config_tables = early_ioremap(tables, nr_tables * sz);
671 if (config_tables == NULL) {
672 pr_err("Could not map Configuration table!\n");
676 tablep = config_tables;
678 for (i = 0; i < efi.systab->nr_tables; i++) {
682 if (efi_enabled(EFI_64BIT)) {
684 guid = ((efi_config_table_64_t *)tablep)->guid;
685 table64 = ((efi_config_table_64_t *)tablep)->table;
690 pr_err("Table located above 4GB, disabling EFI.\n");
691 early_iounmap(config_tables,
692 efi.systab->nr_tables * sz);
697 guid = ((efi_config_table_32_t *)tablep)->guid;
698 table = ((efi_config_table_32_t *)tablep)->table;
700 if (!efi_guidcmp(guid, MPS_TABLE_GUID)) {
702 pr_cont(" MPS=0x%lx ", table);
703 } else if (!efi_guidcmp(guid, ACPI_20_TABLE_GUID)) {
705 pr_cont(" ACPI 2.0=0x%lx ", table);
706 } else if (!efi_guidcmp(guid, ACPI_TABLE_GUID)) {
708 pr_cont(" ACPI=0x%lx ", table);
709 } else if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID)) {
711 pr_cont(" SMBIOS=0x%lx ", table);
713 } else if (!efi_guidcmp(guid, UV_SYSTEM_TABLE_GUID)) {
714 efi.uv_systab = table;
715 pr_cont(" UVsystab=0x%lx ", table);
717 } else if (!efi_guidcmp(guid, HCDP_TABLE_GUID)) {
719 pr_cont(" HCDP=0x%lx ", table);
720 } else if (!efi_guidcmp(guid, UGA_IO_PROTOCOL_GUID)) {
722 pr_cont(" UGA=0x%lx ", table);
727 early_iounmap(config_tables, efi.systab->nr_tables * sz);
731 static int __init efi_runtime_init(void)
733 efi_runtime_services_t *runtime;
736 * Check out the runtime services table. We need to map
737 * the runtime services table so that we can grab the physical
738 * address of several of the EFI runtime functions, needed to
739 * set the firmware into virtual mode.
741 runtime = early_ioremap((unsigned long)efi.systab->runtime,
742 sizeof(efi_runtime_services_t));
744 pr_err("Could not map the runtime service table!\n");
748 * We will only need *early* access to the following
749 * two EFI runtime services before set_virtual_address_map
752 efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
753 efi_phys.set_virtual_address_map =
754 (efi_set_virtual_address_map_t *)
755 runtime->set_virtual_address_map;
757 * Make efi_get_time can be called before entering
760 efi.get_time = phys_efi_get_time;
761 early_iounmap(runtime, sizeof(efi_runtime_services_t));
766 static int __init efi_memmap_init(void)
768 /* Map the EFI memory map */
769 memmap.map = early_ioremap((unsigned long)memmap.phys_map,
770 memmap.nr_map * memmap.desc_size);
771 if (memmap.map == NULL) {
772 pr_err("Could not map the memory map!\n");
775 memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
783 void __init efi_init(void)
786 char vendor[100] = "unknown";
789 struct setup_data *data;
790 struct efi_var_bootdata *efi_var_data;
794 if (boot_params.efi_info.efi_systab_hi ||
795 boot_params.efi_info.efi_memmap_hi) {
796 pr_info("Table located above 4GB, disabling EFI.\n");
799 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
801 efi_phys.systab = (efi_system_table_t *)
802 (boot_params.efi_info.efi_systab |
803 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
806 if (efi_systab_init(efi_phys.systab))
809 pa_data = boot_params.hdr.setup_data;
811 data = early_ioremap(pa_data, sizeof(*efi_var_data));
812 if (data->type == SETUP_EFI_VARS) {
813 efi_var_data = (struct efi_var_bootdata *)data;
815 efi_var_store_size = efi_var_data->store_size;
816 efi_var_remaining_size = efi_var_data->remaining_size;
817 efi_var_max_var_size = efi_var_data->max_var_size;
819 pa_data = data->next;
820 early_iounmap(data, sizeof(*efi_var_data));
823 boot_used_size = efi_var_store_size - efi_var_remaining_size;
825 set_bit(EFI_SYSTEM_TABLES, &x86_efi_facility);
828 * Show what we know for posterity
830 c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
832 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
836 pr_err("Could not map the firmware vendor!\n");
837 early_iounmap(tmp, 2);
839 pr_info("EFI v%u.%.02u by %s\n",
840 efi.systab->hdr.revision >> 16,
841 efi.systab->hdr.revision & 0xffff, vendor);
843 if (efi_config_init(efi.systab->tables, efi.systab->nr_tables))
846 set_bit(EFI_CONFIG_TABLES, &x86_efi_facility);
849 * Note: We currently don't support runtime services on an EFI
850 * that doesn't match the kernel 32/64-bit mode.
853 if (!efi_is_native())
854 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
856 if (disable_runtime || efi_runtime_init())
858 set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
861 if (efi_memmap_init())
864 set_bit(EFI_MEMMAP, &x86_efi_facility);
867 if (efi_is_native()) {
868 x86_platform.get_wallclock = efi_get_time;
869 x86_platform.set_wallclock = efi_set_rtc_mmss;
878 void __init efi_late_init(void)
883 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
887 addr = md->virt_addr;
888 npages = md->num_pages;
890 memrange_efi_to_native(&addr, &npages);
893 set_memory_x(addr, npages);
895 set_memory_nx(addr, npages);
898 static void __init runtime_code_page_mkexec(void)
900 efi_memory_desc_t *md;
903 /* Make EFI runtime service code area executable */
904 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
907 if (md->type != EFI_RUNTIME_SERVICES_CODE)
910 efi_set_executable(md, true);
915 * We can't ioremap data in EFI boot services RAM, because we've already mapped
916 * it as RAM. So, look it up in the existing EFI memory map instead. Only
917 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
919 void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
922 if (WARN_ON(!memmap.map))
924 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
925 efi_memory_desc_t *md = p;
926 u64 size = md->num_pages << EFI_PAGE_SHIFT;
927 u64 end = md->phys_addr + size;
928 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
929 md->type != EFI_BOOT_SERVICES_CODE &&
930 md->type != EFI_BOOT_SERVICES_DATA)
934 if (phys_addr >= md->phys_addr && phys_addr < end) {
935 phys_addr += md->virt_addr - md->phys_addr;
936 return (__force void __iomem *)(unsigned long)phys_addr;
942 void efi_memory_uc(u64 addr, unsigned long size)
944 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
947 npages = round_up(size, page_shift) / page_shift;
948 memrange_efi_to_native(&addr, &npages);
949 set_memory_uc(addr, npages);
953 * This function will switch the EFI runtime services to virtual mode.
954 * Essentially, look through the EFI memmap and map every region that
955 * has the runtime attribute bit set in its memory descriptor and update
956 * that memory descriptor with the virtual address obtained from ioremap().
957 * This enables the runtime services to be called without having to
958 * thunk back into physical mode for every invocation.
960 void __init efi_enter_virtual_mode(void)
962 efi_memory_desc_t *md, *prev_md = NULL;
965 u64 end, systab, start_pfn, end_pfn;
966 void *p, *va, *new_memmap = NULL;
972 * We don't do virtual mode, since we don't do runtime services, on
976 if (!efi_is_native()) {
981 /* Merge contiguous regions of the same type and attribute */
982 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
991 if (prev_md->type != md->type ||
992 prev_md->attribute != md->attribute) {
997 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
999 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
1000 prev_md->num_pages += md->num_pages;
1001 md->type = EFI_RESERVED_TYPE;
1008 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1010 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
1011 md->type != EFI_BOOT_SERVICES_CODE &&
1012 md->type != EFI_BOOT_SERVICES_DATA)
1015 size = md->num_pages << EFI_PAGE_SHIFT;
1016 end = md->phys_addr + size;
1018 start_pfn = PFN_DOWN(md->phys_addr);
1019 end_pfn = PFN_UP(end);
1020 if (pfn_range_is_mapped(start_pfn, end_pfn)) {
1021 va = __va(md->phys_addr);
1023 if (!(md->attribute & EFI_MEMORY_WB))
1024 efi_memory_uc((u64)(unsigned long)va, size);
1026 va = efi_ioremap(md->phys_addr, size,
1027 md->type, md->attribute);
1029 md->virt_addr = (u64) (unsigned long) va;
1032 pr_err("ioremap of 0x%llX failed!\n",
1033 (unsigned long long)md->phys_addr);
1037 systab = (u64) (unsigned long) efi_phys.systab;
1038 if (md->phys_addr <= systab && systab < end) {
1039 systab += md->virt_addr - md->phys_addr;
1040 efi.systab = (efi_system_table_t *) (unsigned long) systab;
1042 new_memmap = krealloc(new_memmap,
1043 (count + 1) * memmap.desc_size,
1045 memcpy(new_memmap + (count * memmap.desc_size), md,
1050 BUG_ON(!efi.systab);
1052 status = phys_efi_set_virtual_address_map(
1053 memmap.desc_size * count,
1055 memmap.desc_version,
1056 (efi_memory_desc_t *)__pa(new_memmap));
1058 if (status != EFI_SUCCESS) {
1059 pr_alert("Unable to switch EFI into virtual mode "
1060 "(status=%lx)!\n", status);
1061 panic("EFI call to SetVirtualAddressMap() failed!");
1065 * Now that EFI is in virtual mode, update the function
1066 * pointers in the runtime service table to the new virtual addresses.
1068 * Call EFI services through wrapper functions.
1070 efi.runtime_version = efi_systab.hdr.revision;
1071 efi.get_time = virt_efi_get_time;
1072 efi.set_time = virt_efi_set_time;
1073 efi.get_wakeup_time = virt_efi_get_wakeup_time;
1074 efi.set_wakeup_time = virt_efi_set_wakeup_time;
1075 efi.get_variable = virt_efi_get_variable;
1076 efi.get_next_variable = virt_efi_get_next_variable;
1077 efi.set_variable = virt_efi_set_variable;
1078 efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
1079 efi.reset_system = virt_efi_reset_system;
1080 efi.set_virtual_address_map = NULL;
1081 efi.query_variable_info = virt_efi_query_variable_info;
1082 efi.update_capsule = virt_efi_update_capsule;
1083 efi.query_capsule_caps = virt_efi_query_capsule_caps;
1084 if (__supported_pte_mask & _PAGE_NX)
1085 runtime_code_page_mkexec();
1091 * Convenience functions to obtain memory types and attributes
1093 u32 efi_mem_type(unsigned long phys_addr)
1095 efi_memory_desc_t *md;
1098 if (!efi_enabled(EFI_MEMMAP))
1101 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1103 if ((md->phys_addr <= phys_addr) &&
1104 (phys_addr < (md->phys_addr +
1105 (md->num_pages << EFI_PAGE_SHIFT))))
1111 u64 efi_mem_attributes(unsigned long phys_addr)
1113 efi_memory_desc_t *md;
1116 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1118 if ((md->phys_addr <= phys_addr) &&
1119 (phys_addr < (md->phys_addr +
1120 (md->num_pages << EFI_PAGE_SHIFT))))
1121 return md->attribute;
1127 * Some firmware has serious problems when using more than 50% of the EFI
1128 * variable store, i.e. it triggers bugs that can brick machines. Ensure that
1129 * we never use more than this safe limit.
1131 * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
1134 efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
1136 efi_status_t status;
1137 u64 storage_size, remaining_size, max_size;
1139 status = efi.query_variable_info(attributes, &storage_size,
1140 &remaining_size, &max_size);
1141 if (status != EFI_SUCCESS)
1144 if (!max_size && remaining_size > size)
1145 printk_once(KERN_ERR FW_BUG "Broken EFI implementation"
1146 " is returning MaxVariableSize=0\n");
1148 * Some firmware implementations refuse to boot if there's insufficient
1149 * space in the variable store. We account for that by refusing the
1150 * write if permitting it would reduce the available space to under
1151 * 50%. However, some firmware won't reclaim variable space until
1152 * after the used (not merely the actively used) space drops below
1153 * a threshold. We can approximate that case with the value calculated
1154 * above. If both the firmware and our calculations indicate that the
1155 * available space would drop below 50%, refuse the write.
1158 if (!storage_size || size > remaining_size ||
1159 (max_size && size > max_size))
1160 return EFI_OUT_OF_RESOURCES;
1162 if (!efi_no_storage_paranoia &&
1163 ((active_size + size + VAR_METADATA_SIZE > storage_size / 2) &&
1164 (remaining_size - size < storage_size / 2)))
1165 return EFI_OUT_OF_RESOURCES;
1169 EXPORT_SYMBOL_GPL(efi_query_variable_store);