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>
54 #include <asm/uv/uv.h>
56 static struct efi efi_phys __initdata;
57 static efi_system_table_t efi_systab __initdata;
59 static efi_config_table_type_t arch_tables[] __initdata = {
61 {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab},
63 {NULL_GUID, NULL, NULL},
66 u64 efi_setup; /* efi setup_data physical address */
68 static int add_efi_memmap __initdata;
69 static int __init setup_add_efi_memmap(char *arg)
74 early_param("add_efi_memmap", setup_add_efi_memmap);
76 static efi_status_t __init phys_efi_set_virtual_address_map(
77 unsigned long memory_map_size,
78 unsigned long descriptor_size,
79 u32 descriptor_version,
80 efi_memory_desc_t *virtual_map)
86 save_pgd = efi_call_phys_prolog();
88 /* Disable interrupts around EFI calls: */
89 local_irq_save(flags);
90 status = efi_call_phys(efi_phys.set_virtual_address_map,
91 memory_map_size, descriptor_size,
92 descriptor_version, virtual_map);
93 local_irq_restore(flags);
95 efi_call_phys_epilog(save_pgd);
100 void __init efi_find_mirror(void)
102 efi_memory_desc_t *md;
103 u64 mirror_size = 0, total_size = 0;
105 for_each_efi_memory_desc(md) {
106 unsigned long long start = md->phys_addr;
107 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
110 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
111 memblock_mark_mirror(start, size);
116 pr_info("Memory: %lldM/%lldM mirrored memory\n",
117 mirror_size>>20, total_size>>20);
121 * Tell the kernel about the EFI memory map. This might include
122 * more than the max 128 entries that can fit in the e820 legacy
123 * (zeropage) memory map.
126 static void __init do_add_efi_memmap(void)
128 efi_memory_desc_t *md;
130 for_each_efi_memory_desc(md) {
131 unsigned long long start = md->phys_addr;
132 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
136 case EFI_LOADER_CODE:
137 case EFI_LOADER_DATA:
138 case EFI_BOOT_SERVICES_CODE:
139 case EFI_BOOT_SERVICES_DATA:
140 case EFI_CONVENTIONAL_MEMORY:
141 if (md->attribute & EFI_MEMORY_WB)
142 e820_type = E820_RAM;
144 e820_type = E820_RESERVED;
146 case EFI_ACPI_RECLAIM_MEMORY:
147 e820_type = E820_ACPI;
149 case EFI_ACPI_MEMORY_NVS:
150 e820_type = E820_NVS;
152 case EFI_UNUSABLE_MEMORY:
153 e820_type = E820_UNUSABLE;
155 case EFI_PERSISTENT_MEMORY:
156 e820_type = E820_PMEM;
160 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
161 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
162 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
164 e820_type = E820_RESERVED;
167 e820_add_region(start, size, e820_type);
169 sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
172 int __init efi_memblock_x86_reserve_range(void)
174 struct efi_info *e = &boot_params.efi_info;
175 struct efi_memory_map_data data;
179 if (efi_enabled(EFI_PARAVIRT))
183 /* Can't handle data above 4GB at this time */
184 if (e->efi_memmap_hi) {
185 pr_err("Memory map is above 4GB, disabling EFI.\n");
188 pmap = e->efi_memmap;
190 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
192 data.phys_map = pmap;
193 data.size = e->efi_memmap_size;
194 data.desc_size = e->efi_memdesc_size;
195 data.desc_version = e->efi_memdesc_version;
197 rv = efi_memmap_init_early(&data);
204 WARN(efi.memmap.desc_version != 1,
205 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
206 efi.memmap.desc_version);
208 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
213 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
214 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
215 #define U64_HIGH_BIT (~(U64_MAX >> 1))
217 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
219 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
223 if (md->num_pages == 0) {
225 } else if (md->num_pages > EFI_PAGES_MAX ||
226 EFI_PAGES_MAX - md->num_pages <
227 (md->phys_addr >> EFI_PAGE_SHIFT)) {
228 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
229 >> OVERFLOW_ADDR_SHIFT;
231 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
237 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
240 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
241 i, efi_md_typeattr_format(buf, sizeof(buf), md),
242 md->phys_addr, end_hi, end);
244 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
245 i, efi_md_typeattr_format(buf, sizeof(buf), md),
251 static void __init efi_clean_memmap(void)
253 efi_memory_desc_t *out = efi.memmap.map;
254 const efi_memory_desc_t *in = out;
255 const efi_memory_desc_t *end = efi.memmap.map_end;
258 for (i = n_removal = 0; in < end; i++) {
259 if (efi_memmap_entry_valid(in, i)) {
261 memcpy(out, in, efi.memmap.desc_size);
262 out = (void *)out + efi.memmap.desc_size;
266 in = (void *)in + efi.memmap.desc_size;
270 u64 size = efi.memmap.nr_map - n_removal;
272 pr_warn("Removing %d invalid memory map entries.\n", n_removal);
273 efi_memmap_install(efi.memmap.phys_map, size);
277 void __init efi_print_memmap(void)
279 efi_memory_desc_t *md;
282 for_each_efi_memory_desc(md) {
285 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
286 i++, efi_md_typeattr_format(buf, sizeof(buf), md),
288 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
289 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
293 static int __init efi_systab_init(void *phys)
295 if (efi_enabled(EFI_64BIT)) {
296 efi_system_table_64_t *systab64;
297 struct efi_setup_data *data = NULL;
301 data = early_memremap(efi_setup, sizeof(*data));
305 systab64 = early_memremap((unsigned long)phys,
307 if (systab64 == NULL) {
308 pr_err("Couldn't map the system table!\n");
310 early_memunmap(data, sizeof(*data));
314 efi_systab.hdr = systab64->hdr;
315 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
317 tmp |= data ? data->fw_vendor : systab64->fw_vendor;
318 efi_systab.fw_revision = systab64->fw_revision;
319 efi_systab.con_in_handle = systab64->con_in_handle;
320 tmp |= systab64->con_in_handle;
321 efi_systab.con_in = systab64->con_in;
322 tmp |= systab64->con_in;
323 efi_systab.con_out_handle = systab64->con_out_handle;
324 tmp |= systab64->con_out_handle;
325 efi_systab.con_out = systab64->con_out;
326 tmp |= systab64->con_out;
327 efi_systab.stderr_handle = systab64->stderr_handle;
328 tmp |= systab64->stderr_handle;
329 efi_systab.stderr = systab64->stderr;
330 tmp |= systab64->stderr;
331 efi_systab.runtime = data ?
332 (void *)(unsigned long)data->runtime :
333 (void *)(unsigned long)systab64->runtime;
334 tmp |= data ? data->runtime : systab64->runtime;
335 efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
336 tmp |= systab64->boottime;
337 efi_systab.nr_tables = systab64->nr_tables;
338 efi_systab.tables = data ? (unsigned long)data->tables :
340 tmp |= data ? data->tables : systab64->tables;
342 early_memunmap(systab64, sizeof(*systab64));
344 early_memunmap(data, sizeof(*data));
347 pr_err("EFI data located above 4GB, disabling EFI.\n");
352 efi_system_table_32_t *systab32;
354 systab32 = early_memremap((unsigned long)phys,
356 if (systab32 == NULL) {
357 pr_err("Couldn't map the system table!\n");
361 efi_systab.hdr = systab32->hdr;
362 efi_systab.fw_vendor = systab32->fw_vendor;
363 efi_systab.fw_revision = systab32->fw_revision;
364 efi_systab.con_in_handle = systab32->con_in_handle;
365 efi_systab.con_in = systab32->con_in;
366 efi_systab.con_out_handle = systab32->con_out_handle;
367 efi_systab.con_out = systab32->con_out;
368 efi_systab.stderr_handle = systab32->stderr_handle;
369 efi_systab.stderr = systab32->stderr;
370 efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
371 efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
372 efi_systab.nr_tables = systab32->nr_tables;
373 efi_systab.tables = systab32->tables;
375 early_memunmap(systab32, sizeof(*systab32));
378 efi.systab = &efi_systab;
381 * Verify the EFI Table
383 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
384 pr_err("System table signature incorrect!\n");
387 if ((efi.systab->hdr.revision >> 16) == 0)
388 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
389 efi.systab->hdr.revision >> 16,
390 efi.systab->hdr.revision & 0xffff);
395 static int __init efi_runtime_init32(void)
397 efi_runtime_services_32_t *runtime;
399 runtime = early_memremap((unsigned long)efi.systab->runtime,
400 sizeof(efi_runtime_services_32_t));
402 pr_err("Could not map the runtime service table!\n");
407 * We will only need *early* access to the SetVirtualAddressMap
408 * EFI runtime service. All other runtime services will be called
409 * via the virtual mapping.
411 efi_phys.set_virtual_address_map =
412 (efi_set_virtual_address_map_t *)
413 (unsigned long)runtime->set_virtual_address_map;
414 early_memunmap(runtime, sizeof(efi_runtime_services_32_t));
419 static int __init efi_runtime_init64(void)
421 efi_runtime_services_64_t *runtime;
423 runtime = early_memremap((unsigned long)efi.systab->runtime,
424 sizeof(efi_runtime_services_64_t));
426 pr_err("Could not map the runtime service table!\n");
431 * We will only need *early* access to the SetVirtualAddressMap
432 * EFI runtime service. All other runtime services will be called
433 * via the virtual mapping.
435 efi_phys.set_virtual_address_map =
436 (efi_set_virtual_address_map_t *)
437 (unsigned long)runtime->set_virtual_address_map;
438 early_memunmap(runtime, sizeof(efi_runtime_services_64_t));
443 static int __init efi_runtime_init(void)
448 * Check out the runtime services table. We need to map
449 * the runtime services table so that we can grab the physical
450 * address of several of the EFI runtime functions, needed to
451 * set the firmware into virtual mode.
453 * When EFI_PARAVIRT is in force then we could not map runtime
454 * service memory region because we do not have direct access to it.
455 * However, runtime services are available through proxy functions
456 * (e.g. in case of Xen dom0 EFI implementation they call special
457 * hypercall which executes relevant EFI functions) and that is why
458 * they are always enabled.
461 if (!efi_enabled(EFI_PARAVIRT)) {
462 if (efi_enabled(EFI_64BIT))
463 rv = efi_runtime_init64();
465 rv = efi_runtime_init32();
471 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
476 void __init efi_init(void)
479 char vendor[100] = "unknown";
484 if (boot_params.efi_info.efi_systab_hi ||
485 boot_params.efi_info.efi_memmap_hi) {
486 pr_info("Table located above 4GB, disabling EFI.\n");
489 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
491 efi_phys.systab = (efi_system_table_t *)
492 (boot_params.efi_info.efi_systab |
493 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
496 if (efi_systab_init(efi_phys.systab))
499 efi.config_table = (unsigned long)efi.systab->tables;
500 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor;
501 efi.runtime = (unsigned long)efi.systab->runtime;
504 * Show what we know for posterity
506 c16 = tmp = early_memremap(efi.systab->fw_vendor, 2);
508 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
512 pr_err("Could not map the firmware vendor!\n");
513 early_memunmap(tmp, 2);
515 pr_info("EFI v%u.%.02u by %s\n",
516 efi.systab->hdr.revision >> 16,
517 efi.systab->hdr.revision & 0xffff, vendor);
519 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
522 if (efi_config_init(arch_tables))
526 * Note: We currently don't support runtime services on an EFI
527 * that doesn't match the kernel 32/64-bit mode.
530 if (!efi_runtime_supported())
531 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
533 if (efi_runtime_disabled() || efi_runtime_init()) {
541 if (efi_enabled(EFI_DBG))
545 void __init efi_late_init(void)
550 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
554 addr = md->virt_addr;
555 npages = md->num_pages;
557 memrange_efi_to_native(&addr, &npages);
560 set_memory_x(addr, npages);
562 set_memory_nx(addr, npages);
565 void __init runtime_code_page_mkexec(void)
567 efi_memory_desc_t *md;
569 /* Make EFI runtime service code area executable */
570 for_each_efi_memory_desc(md) {
571 if (md->type != EFI_RUNTIME_SERVICES_CODE)
574 efi_set_executable(md, true);
578 void __init efi_memory_uc(u64 addr, unsigned long size)
580 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
583 npages = round_up(size, page_shift) / page_shift;
584 memrange_efi_to_native(&addr, &npages);
585 set_memory_uc(addr, npages);
588 void __init old_map_region(efi_memory_desc_t *md)
590 u64 start_pfn, end_pfn, end;
594 start_pfn = PFN_DOWN(md->phys_addr);
595 size = md->num_pages << PAGE_SHIFT;
596 end = md->phys_addr + size;
597 end_pfn = PFN_UP(end);
599 if (pfn_range_is_mapped(start_pfn, end_pfn)) {
600 va = __va(md->phys_addr);
602 if (!(md->attribute & EFI_MEMORY_WB))
603 efi_memory_uc((u64)(unsigned long)va, size);
605 va = efi_ioremap(md->phys_addr, size,
606 md->type, md->attribute);
608 md->virt_addr = (u64) (unsigned long) va;
610 pr_err("ioremap of 0x%llX failed!\n",
611 (unsigned long long)md->phys_addr);
614 /* Merge contiguous regions of the same type and attribute */
615 static void __init efi_merge_regions(void)
617 efi_memory_desc_t *md, *prev_md = NULL;
619 for_each_efi_memory_desc(md) {
627 if (prev_md->type != md->type ||
628 prev_md->attribute != md->attribute) {
633 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
635 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
636 prev_md->num_pages += md->num_pages;
637 md->type = EFI_RESERVED_TYPE;
645 static void __init get_systab_virt_addr(efi_memory_desc_t *md)
650 size = md->num_pages << EFI_PAGE_SHIFT;
651 end = md->phys_addr + size;
652 systab = (u64)(unsigned long)efi_phys.systab;
653 if (md->phys_addr <= systab && systab < end) {
654 systab += md->virt_addr - md->phys_addr;
655 efi.systab = (efi_system_table_t *)(unsigned long)systab;
659 static void *realloc_pages(void *old_memmap, int old_shift)
663 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
668 * A first-time allocation doesn't have anything to copy.
673 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
676 free_pages((unsigned long)old_memmap, old_shift);
681 * Iterate the EFI memory map in reverse order because the regions
682 * will be mapped top-down. The end result is the same as if we had
683 * mapped things forward, but doesn't require us to change the
684 * existing implementation of efi_map_region().
686 static inline void *efi_map_next_entry_reverse(void *entry)
690 return efi.memmap.map_end - efi.memmap.desc_size;
692 entry -= efi.memmap.desc_size;
693 if (entry < efi.memmap.map)
700 * efi_map_next_entry - Return the next EFI memory map descriptor
701 * @entry: Previous EFI memory map descriptor
703 * This is a helper function to iterate over the EFI memory map, which
704 * we do in different orders depending on the current configuration.
706 * To begin traversing the memory map @entry must be %NULL.
708 * Returns %NULL when we reach the end of the memory map.
710 static void *efi_map_next_entry(void *entry)
712 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
714 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
715 * config table feature requires us to map all entries
716 * in the same order as they appear in the EFI memory
717 * map. That is to say, entry N must have a lower
718 * virtual address than entry N+1. This is because the
719 * firmware toolchain leaves relative references in
720 * the code/data sections, which are split and become
721 * separate EFI memory regions. Mapping things
722 * out-of-order leads to the firmware accessing
723 * unmapped addresses.
725 * Since we need to map things this way whether or not
726 * the kernel actually makes use of
727 * EFI_PROPERTIES_TABLE, let's just switch to this
728 * scheme by default for 64-bit.
730 return efi_map_next_entry_reverse(entry);
735 return efi.memmap.map;
737 entry += efi.memmap.desc_size;
738 if (entry >= efi.memmap.map_end)
744 static bool should_map_region(efi_memory_desc_t *md)
747 * Runtime regions always require runtime mappings (obviously).
749 if (md->attribute & EFI_MEMORY_RUNTIME)
753 * 32-bit EFI doesn't suffer from the bug that requires us to
754 * reserve boot services regions, and mixed mode support
755 * doesn't exist for 32-bit kernels.
757 if (IS_ENABLED(CONFIG_X86_32))
761 * Map all of RAM so that we can access arguments in the 1:1
762 * mapping when making EFI runtime calls.
764 if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) {
765 if (md->type == EFI_CONVENTIONAL_MEMORY ||
766 md->type == EFI_LOADER_DATA ||
767 md->type == EFI_LOADER_CODE)
772 * Map boot services regions as a workaround for buggy
773 * firmware that accesses them even when they shouldn't.
775 * See efi_{reserve,free}_boot_services().
777 if (md->type == EFI_BOOT_SERVICES_CODE ||
778 md->type == EFI_BOOT_SERVICES_DATA)
785 * Map the efi memory ranges of the runtime services and update new_mmap with
788 static void * __init efi_map_regions(int *count, int *pg_shift)
790 void *p, *new_memmap = NULL;
791 unsigned long left = 0;
792 unsigned long desc_size;
793 efi_memory_desc_t *md;
795 desc_size = efi.memmap.desc_size;
798 while ((p = efi_map_next_entry(p))) {
801 if (!should_map_region(md))
805 get_systab_virt_addr(md);
807 if (left < desc_size) {
808 new_memmap = realloc_pages(new_memmap, *pg_shift);
812 left += PAGE_SIZE << *pg_shift;
816 memcpy(new_memmap + (*count * desc_size), md, desc_size);
825 static void __init kexec_enter_virtual_mode(void)
827 #ifdef CONFIG_KEXEC_CORE
828 efi_memory_desc_t *md;
829 unsigned int num_pages;
834 * We don't do virtual mode, since we don't do runtime services, on
837 if (!efi_is_native()) {
839 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
843 if (efi_alloc_page_tables()) {
844 pr_err("Failed to allocate EFI page tables\n");
845 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
850 * Map efi regions which were passed via setup_data. The virt_addr is a
851 * fixed addr which was used in first kernel of a kexec boot.
853 for_each_efi_memory_desc(md) {
854 efi_map_region_fixed(md); /* FIXME: add error handling */
855 get_systab_virt_addr(md);
859 * Unregister the early EFI memmap from efi_init() and install
860 * the new EFI memory map.
864 if (efi_memmap_init_late(efi.memmap.phys_map,
865 efi.memmap.desc_size * efi.memmap.nr_map)) {
866 pr_err("Failed to remap late EFI memory map\n");
867 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
873 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
874 num_pages >>= PAGE_SHIFT;
876 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
877 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
881 efi_sync_low_kernel_mappings();
884 * Now that EFI is in virtual mode, update the function
885 * pointers in the runtime service table to the new virtual addresses.
887 * Call EFI services through wrapper functions.
889 efi.runtime_version = efi_systab.hdr.revision;
891 efi_native_runtime_setup();
893 efi.set_virtual_address_map = NULL;
895 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
896 runtime_code_page_mkexec();
898 /* clean DUMMY object */
899 efi_delete_dummy_variable();
904 * This function will switch the EFI runtime services to virtual mode.
905 * Essentially, we look through the EFI memmap and map every region that
906 * has the runtime attribute bit set in its memory descriptor into the
907 * efi_pgd page table.
909 * The old method which used to update that memory descriptor with the
910 * virtual address obtained from ioremap() is still supported when the
911 * kernel is booted with efi=old_map on its command line. Same old
912 * method enabled the runtime services to be called without having to
913 * thunk back into physical mode for every invocation.
915 * The new method does a pagetable switch in a preemption-safe manner
916 * so that we're in a different address space when calling a runtime
917 * function. For function arguments passing we do copy the PUDs of the
918 * kernel page table into efi_pgd prior to each call.
920 * Specially for kexec boot, efi runtime maps in previous kernel should
921 * be passed in via setup_data. In that case runtime ranges will be mapped
922 * to the same virtual addresses as the first kernel, see
923 * kexec_enter_virtual_mode().
925 static void __init __efi_enter_virtual_mode(void)
927 int count = 0, pg_shift = 0;
928 void *new_memmap = NULL;
934 if (efi_alloc_page_tables()) {
935 pr_err("Failed to allocate EFI page tables\n");
936 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
941 new_memmap = efi_map_regions(&count, &pg_shift);
943 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
944 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
948 pa = __pa(new_memmap);
951 * Unregister the early EFI memmap from efi_init() and install
952 * the new EFI memory map that we are about to pass to the
953 * firmware via SetVirtualAddressMap().
957 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
958 pr_err("Failed to remap late EFI memory map\n");
959 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
965 if (efi_setup_page_tables(pa, 1 << pg_shift)) {
966 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
970 efi_sync_low_kernel_mappings();
972 if (efi_is_native()) {
973 status = phys_efi_set_virtual_address_map(
974 efi.memmap.desc_size * count,
975 efi.memmap.desc_size,
976 efi.memmap.desc_version,
977 (efi_memory_desc_t *)pa);
979 status = efi_thunk_set_virtual_address_map(
980 efi_phys.set_virtual_address_map,
981 efi.memmap.desc_size * count,
982 efi.memmap.desc_size,
983 efi.memmap.desc_version,
984 (efi_memory_desc_t *)pa);
987 if (status != EFI_SUCCESS) {
988 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
990 panic("EFI call to SetVirtualAddressMap() failed!");
994 * Now that EFI is in virtual mode, update the function
995 * pointers in the runtime service table to the new virtual addresses.
997 * Call EFI services through wrapper functions.
999 efi.runtime_version = efi_systab.hdr.revision;
1001 if (efi_is_native())
1002 efi_native_runtime_setup();
1004 efi_thunk_runtime_setup();
1006 efi.set_virtual_address_map = NULL;
1009 * Apply more restrictive page table mapping attributes now that
1010 * SVAM() has been called and the firmware has performed all
1011 * necessary relocation fixups for the new virtual addresses.
1013 efi_runtime_update_mappings();
1014 efi_dump_pagetable();
1016 /* clean DUMMY object */
1017 efi_delete_dummy_variable();
1020 void __init efi_enter_virtual_mode(void)
1022 if (efi_enabled(EFI_PARAVIRT))
1026 kexec_enter_virtual_mode();
1028 __efi_enter_virtual_mode();
1032 * Convenience functions to obtain memory types and attributes
1034 u32 efi_mem_type(unsigned long phys_addr)
1036 efi_memory_desc_t *md;
1038 if (!efi_enabled(EFI_MEMMAP))
1041 for_each_efi_memory_desc(md) {
1042 if ((md->phys_addr <= phys_addr) &&
1043 (phys_addr < (md->phys_addr +
1044 (md->num_pages << EFI_PAGE_SHIFT))))
1050 static int __init arch_parse_efi_cmdline(char *str)
1053 pr_warn("need at least one option\n");
1057 if (parse_option_str(str, "old_map"))
1058 set_bit(EFI_OLD_MEMMAP, &efi.flags);
1062 early_param("efi", arch_parse_efi_cmdline);