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>
57 static struct efi efi_phys __initdata
;
58 static efi_system_table_t efi_systab __initdata
;
60 static efi_config_table_type_t arch_tables
[] __initdata
= {
62 {UV_SYSTEM_TABLE_GUID
, "UVsystab", &efi
.uv_systab
},
64 {NULL_GUID
, NULL
, NULL
},
67 u64 efi_setup
; /* efi setup_data physical address */
69 static int add_efi_memmap __initdata
;
70 static int __init
setup_add_efi_memmap(char *arg
)
75 early_param("add_efi_memmap", setup_add_efi_memmap
);
77 static efi_status_t __init
phys_efi_set_virtual_address_map(
78 unsigned long memory_map_size
,
79 unsigned long descriptor_size
,
80 u32 descriptor_version
,
81 efi_memory_desc_t
*virtual_map
)
87 save_pgd
= efi_call_phys_prolog();
89 /* Disable interrupts around EFI calls: */
90 local_irq_save(flags
);
91 status
= efi_call_phys(efi_phys
.set_virtual_address_map
,
92 memory_map_size
, descriptor_size
,
93 descriptor_version
, virtual_map
);
94 local_irq_restore(flags
);
96 efi_call_phys_epilog(save_pgd
);
101 void __init
efi_find_mirror(void)
103 efi_memory_desc_t
*md
;
104 u64 mirror_size
= 0, total_size
= 0;
106 for_each_efi_memory_desc(md
) {
107 unsigned long long start
= md
->phys_addr
;
108 unsigned long long size
= md
->num_pages
<< EFI_PAGE_SHIFT
;
111 if (md
->attribute
& EFI_MEMORY_MORE_RELIABLE
) {
112 memblock_mark_mirror(start
, size
);
117 pr_info("Memory: %lldM/%lldM mirrored memory\n",
118 mirror_size
>>20, total_size
>>20);
122 * Tell the kernel about the EFI memory map. This might include
123 * more than the max 128 entries that can fit in the e820 legacy
124 * (zeropage) memory map.
127 static void __init
do_add_efi_memmap(void)
129 efi_memory_desc_t
*md
;
131 for_each_efi_memory_desc(md
) {
132 unsigned long long start
= md
->phys_addr
;
133 unsigned long long size
= md
->num_pages
<< EFI_PAGE_SHIFT
;
137 case EFI_LOADER_CODE
:
138 case EFI_LOADER_DATA
:
139 case EFI_BOOT_SERVICES_CODE
:
140 case EFI_BOOT_SERVICES_DATA
:
141 case EFI_CONVENTIONAL_MEMORY
:
142 if (md
->attribute
& EFI_MEMORY_WB
)
143 e820_type
= E820_RAM
;
145 e820_type
= E820_RESERVED
;
147 case EFI_ACPI_RECLAIM_MEMORY
:
148 e820_type
= E820_ACPI
;
150 case EFI_ACPI_MEMORY_NVS
:
151 e820_type
= E820_NVS
;
153 case EFI_UNUSABLE_MEMORY
:
154 e820_type
= E820_UNUSABLE
;
156 case EFI_PERSISTENT_MEMORY
:
157 e820_type
= E820_PMEM
;
161 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
162 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
163 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
165 e820_type
= E820_RESERVED
;
168 e820_add_region(start
, size
, e820_type
);
170 sanitize_e820_map(e820
.map
, ARRAY_SIZE(e820
.map
), &e820
.nr_map
);
173 int __init
efi_memblock_x86_reserve_range(void)
175 struct efi_info
*e
= &boot_params
.efi_info
;
178 if (efi_enabled(EFI_PARAVIRT
))
182 /* Can't handle data above 4GB at this time */
183 if (e
->efi_memmap_hi
) {
184 pr_err("Memory map is above 4GB, disabling EFI.\n");
187 pmap
= e
->efi_memmap
;
189 pmap
= (e
->efi_memmap
| ((__u64
)e
->efi_memmap_hi
<< 32));
191 efi
.memmap
.phys_map
= pmap
;
192 efi
.memmap
.nr_map
= e
->efi_memmap_size
/
194 efi
.memmap
.desc_size
= e
->efi_memdesc_size
;
195 efi
.memmap
.desc_version
= e
->efi_memdesc_version
;
197 WARN(efi
.memmap
.desc_version
!= 1,
198 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
199 efi
.memmap
.desc_version
);
201 memblock_reserve(pmap
, efi
.memmap
.nr_map
* efi
.memmap
.desc_size
);
206 void __init
efi_print_memmap(void)
208 efi_memory_desc_t
*md
;
211 for_each_efi_memory_desc(md
) {
214 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
215 i
++, efi_md_typeattr_format(buf
, sizeof(buf
), md
),
217 md
->phys_addr
+ (md
->num_pages
<< EFI_PAGE_SHIFT
) - 1,
218 (md
->num_pages
>> (20 - EFI_PAGE_SHIFT
)));
222 void __init
efi_unmap_memmap(void)
226 clear_bit(EFI_MEMMAP
, &efi
.flags
);
228 size
= efi
.memmap
.nr_map
* efi
.memmap
.desc_size
;
229 if (efi
.memmap
.map
) {
230 early_memunmap(efi
.memmap
.map
, size
);
231 efi
.memmap
.map
= NULL
;
235 static int __init
efi_systab_init(void *phys
)
237 if (efi_enabled(EFI_64BIT
)) {
238 efi_system_table_64_t
*systab64
;
239 struct efi_setup_data
*data
= NULL
;
243 data
= early_memremap(efi_setup
, sizeof(*data
));
247 systab64
= early_memremap((unsigned long)phys
,
249 if (systab64
== NULL
) {
250 pr_err("Couldn't map the system table!\n");
252 early_memunmap(data
, sizeof(*data
));
256 efi_systab
.hdr
= systab64
->hdr
;
257 efi_systab
.fw_vendor
= data
? (unsigned long)data
->fw_vendor
:
259 tmp
|= data
? data
->fw_vendor
: systab64
->fw_vendor
;
260 efi_systab
.fw_revision
= systab64
->fw_revision
;
261 efi_systab
.con_in_handle
= systab64
->con_in_handle
;
262 tmp
|= systab64
->con_in_handle
;
263 efi_systab
.con_in
= systab64
->con_in
;
264 tmp
|= systab64
->con_in
;
265 efi_systab
.con_out_handle
= systab64
->con_out_handle
;
266 tmp
|= systab64
->con_out_handle
;
267 efi_systab
.con_out
= systab64
->con_out
;
268 tmp
|= systab64
->con_out
;
269 efi_systab
.stderr_handle
= systab64
->stderr_handle
;
270 tmp
|= systab64
->stderr_handle
;
271 efi_systab
.stderr
= systab64
->stderr
;
272 tmp
|= systab64
->stderr
;
273 efi_systab
.runtime
= data
?
274 (void *)(unsigned long)data
->runtime
:
275 (void *)(unsigned long)systab64
->runtime
;
276 tmp
|= data
? data
->runtime
: systab64
->runtime
;
277 efi_systab
.boottime
= (void *)(unsigned long)systab64
->boottime
;
278 tmp
|= systab64
->boottime
;
279 efi_systab
.nr_tables
= systab64
->nr_tables
;
280 efi_systab
.tables
= data
? (unsigned long)data
->tables
:
282 tmp
|= data
? data
->tables
: systab64
->tables
;
284 early_memunmap(systab64
, sizeof(*systab64
));
286 early_memunmap(data
, sizeof(*data
));
289 pr_err("EFI data located above 4GB, disabling EFI.\n");
294 efi_system_table_32_t
*systab32
;
296 systab32
= early_memremap((unsigned long)phys
,
298 if (systab32
== NULL
) {
299 pr_err("Couldn't map the system table!\n");
303 efi_systab
.hdr
= systab32
->hdr
;
304 efi_systab
.fw_vendor
= systab32
->fw_vendor
;
305 efi_systab
.fw_revision
= systab32
->fw_revision
;
306 efi_systab
.con_in_handle
= systab32
->con_in_handle
;
307 efi_systab
.con_in
= systab32
->con_in
;
308 efi_systab
.con_out_handle
= systab32
->con_out_handle
;
309 efi_systab
.con_out
= systab32
->con_out
;
310 efi_systab
.stderr_handle
= systab32
->stderr_handle
;
311 efi_systab
.stderr
= systab32
->stderr
;
312 efi_systab
.runtime
= (void *)(unsigned long)systab32
->runtime
;
313 efi_systab
.boottime
= (void *)(unsigned long)systab32
->boottime
;
314 efi_systab
.nr_tables
= systab32
->nr_tables
;
315 efi_systab
.tables
= systab32
->tables
;
317 early_memunmap(systab32
, sizeof(*systab32
));
320 efi
.systab
= &efi_systab
;
323 * Verify the EFI Table
325 if (efi
.systab
->hdr
.signature
!= EFI_SYSTEM_TABLE_SIGNATURE
) {
326 pr_err("System table signature incorrect!\n");
329 if ((efi
.systab
->hdr
.revision
>> 16) == 0)
330 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
331 efi
.systab
->hdr
.revision
>> 16,
332 efi
.systab
->hdr
.revision
& 0xffff);
337 static int __init
efi_runtime_init32(void)
339 efi_runtime_services_32_t
*runtime
;
341 runtime
= early_memremap((unsigned long)efi
.systab
->runtime
,
342 sizeof(efi_runtime_services_32_t
));
344 pr_err("Could not map the runtime service table!\n");
349 * We will only need *early* access to the SetVirtualAddressMap
350 * EFI runtime service. All other runtime services will be called
351 * via the virtual mapping.
353 efi_phys
.set_virtual_address_map
=
354 (efi_set_virtual_address_map_t
*)
355 (unsigned long)runtime
->set_virtual_address_map
;
356 early_memunmap(runtime
, sizeof(efi_runtime_services_32_t
));
361 static int __init
efi_runtime_init64(void)
363 efi_runtime_services_64_t
*runtime
;
365 runtime
= early_memremap((unsigned long)efi
.systab
->runtime
,
366 sizeof(efi_runtime_services_64_t
));
368 pr_err("Could not map the runtime service table!\n");
373 * We will only need *early* access to the SetVirtualAddressMap
374 * EFI runtime service. All other runtime services will be called
375 * via the virtual mapping.
377 efi_phys
.set_virtual_address_map
=
378 (efi_set_virtual_address_map_t
*)
379 (unsigned long)runtime
->set_virtual_address_map
;
380 early_memunmap(runtime
, sizeof(efi_runtime_services_64_t
));
385 static int __init
efi_runtime_init(void)
390 * Check out the runtime services table. We need to map
391 * the runtime services table so that we can grab the physical
392 * address of several of the EFI runtime functions, needed to
393 * set the firmware into virtual mode.
395 * When EFI_PARAVIRT is in force then we could not map runtime
396 * service memory region because we do not have direct access to it.
397 * However, runtime services are available through proxy functions
398 * (e.g. in case of Xen dom0 EFI implementation they call special
399 * hypercall which executes relevant EFI functions) and that is why
400 * they are always enabled.
403 if (!efi_enabled(EFI_PARAVIRT
)) {
404 if (efi_enabled(EFI_64BIT
))
405 rv
= efi_runtime_init64();
407 rv
= efi_runtime_init32();
413 set_bit(EFI_RUNTIME_SERVICES
, &efi
.flags
);
418 static int __init
efi_memmap_init(void)
420 unsigned long addr
, size
;
422 if (efi_enabled(EFI_PARAVIRT
))
425 /* Map the EFI memory map */
426 size
= efi
.memmap
.nr_map
* efi
.memmap
.desc_size
;
427 addr
= (unsigned long)efi
.memmap
.phys_map
;
429 efi
.memmap
.map
= early_memremap(addr
, size
);
430 if (efi
.memmap
.map
== NULL
) {
431 pr_err("Could not map the memory map!\n");
435 efi
.memmap
.map_end
= efi
.memmap
.map
+ size
;
440 set_bit(EFI_MEMMAP
, &efi
.flags
);
445 void __init
efi_init(void)
448 char vendor
[100] = "unknown";
453 if (boot_params
.efi_info
.efi_systab_hi
||
454 boot_params
.efi_info
.efi_memmap_hi
) {
455 pr_info("Table located above 4GB, disabling EFI.\n");
458 efi_phys
.systab
= (efi_system_table_t
*)boot_params
.efi_info
.efi_systab
;
460 efi_phys
.systab
= (efi_system_table_t
*)
461 (boot_params
.efi_info
.efi_systab
|
462 ((__u64
)boot_params
.efi_info
.efi_systab_hi
<<32));
465 if (efi_systab_init(efi_phys
.systab
))
468 efi
.config_table
= (unsigned long)efi
.systab
->tables
;
469 efi
.fw_vendor
= (unsigned long)efi
.systab
->fw_vendor
;
470 efi
.runtime
= (unsigned long)efi
.systab
->runtime
;
473 * Show what we know for posterity
475 c16
= tmp
= early_memremap(efi
.systab
->fw_vendor
, 2);
477 for (i
= 0; i
< sizeof(vendor
) - 1 && *c16
; ++i
)
481 pr_err("Could not map the firmware vendor!\n");
482 early_memunmap(tmp
, 2);
484 pr_info("EFI v%u.%.02u by %s\n",
485 efi
.systab
->hdr
.revision
>> 16,
486 efi
.systab
->hdr
.revision
& 0xffff, vendor
);
488 if (efi_reuse_config(efi
.systab
->tables
, efi
.systab
->nr_tables
))
491 if (efi_config_init(arch_tables
))
495 * Note: We currently don't support runtime services on an EFI
496 * that doesn't match the kernel 32/64-bit mode.
499 if (!efi_runtime_supported())
500 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
502 if (efi_runtime_disabled() || efi_runtime_init())
505 if (efi_memmap_init())
508 if (efi_enabled(EFI_DBG
))
514 void __init
efi_late_init(void)
519 void __init
efi_set_executable(efi_memory_desc_t
*md
, bool executable
)
523 addr
= md
->virt_addr
;
524 npages
= md
->num_pages
;
526 memrange_efi_to_native(&addr
, &npages
);
529 set_memory_x(addr
, npages
);
531 set_memory_nx(addr
, npages
);
534 void __init
runtime_code_page_mkexec(void)
536 efi_memory_desc_t
*md
;
538 /* Make EFI runtime service code area executable */
539 for_each_efi_memory_desc(md
) {
540 if (md
->type
!= EFI_RUNTIME_SERVICES_CODE
)
543 efi_set_executable(md
, true);
547 void __init
efi_memory_uc(u64 addr
, unsigned long size
)
549 unsigned long page_shift
= 1UL << EFI_PAGE_SHIFT
;
552 npages
= round_up(size
, page_shift
) / page_shift
;
553 memrange_efi_to_native(&addr
, &npages
);
554 set_memory_uc(addr
, npages
);
557 void __init
old_map_region(efi_memory_desc_t
*md
)
559 u64 start_pfn
, end_pfn
, end
;
563 start_pfn
= PFN_DOWN(md
->phys_addr
);
564 size
= md
->num_pages
<< PAGE_SHIFT
;
565 end
= md
->phys_addr
+ size
;
566 end_pfn
= PFN_UP(end
);
568 if (pfn_range_is_mapped(start_pfn
, end_pfn
)) {
569 va
= __va(md
->phys_addr
);
571 if (!(md
->attribute
& EFI_MEMORY_WB
))
572 efi_memory_uc((u64
)(unsigned long)va
, size
);
574 va
= efi_ioremap(md
->phys_addr
, size
,
575 md
->type
, md
->attribute
);
577 md
->virt_addr
= (u64
) (unsigned long) va
;
579 pr_err("ioremap of 0x%llX failed!\n",
580 (unsigned long long)md
->phys_addr
);
583 /* Merge contiguous regions of the same type and attribute */
584 static void __init
efi_merge_regions(void)
586 efi_memory_desc_t
*md
, *prev_md
= NULL
;
588 for_each_efi_memory_desc(md
) {
596 if (prev_md
->type
!= md
->type
||
597 prev_md
->attribute
!= md
->attribute
) {
602 prev_size
= prev_md
->num_pages
<< EFI_PAGE_SHIFT
;
604 if (md
->phys_addr
== (prev_md
->phys_addr
+ prev_size
)) {
605 prev_md
->num_pages
+= md
->num_pages
;
606 md
->type
= EFI_RESERVED_TYPE
;
614 static void __init
get_systab_virt_addr(efi_memory_desc_t
*md
)
619 size
= md
->num_pages
<< EFI_PAGE_SHIFT
;
620 end
= md
->phys_addr
+ size
;
621 systab
= (u64
)(unsigned long)efi_phys
.systab
;
622 if (md
->phys_addr
<= systab
&& systab
< end
) {
623 systab
+= md
->virt_addr
- md
->phys_addr
;
624 efi
.systab
= (efi_system_table_t
*)(unsigned long)systab
;
628 static void __init
save_runtime_map(void)
630 #ifdef CONFIG_KEXEC_CORE
631 unsigned long desc_size
;
632 efi_memory_desc_t
*md
;
633 void *tmp
, *q
= NULL
;
636 if (efi_enabled(EFI_OLD_MEMMAP
))
639 desc_size
= efi
.memmap
.desc_size
;
641 for_each_efi_memory_desc(md
) {
642 if (!(md
->attribute
& EFI_MEMORY_RUNTIME
) ||
643 (md
->type
== EFI_BOOT_SERVICES_CODE
) ||
644 (md
->type
== EFI_BOOT_SERVICES_DATA
))
646 tmp
= krealloc(q
, (count
+ 1) * desc_size
, GFP_KERNEL
);
651 memcpy(q
+ count
* desc_size
, md
, desc_size
);
655 efi_runtime_map_setup(q
, count
, desc_size
);
660 pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
664 static void *realloc_pages(void *old_memmap
, int old_shift
)
668 ret
= (void *)__get_free_pages(GFP_KERNEL
, old_shift
+ 1);
673 * A first-time allocation doesn't have anything to copy.
678 memcpy(ret
, old_memmap
, PAGE_SIZE
<< old_shift
);
681 free_pages((unsigned long)old_memmap
, old_shift
);
686 * Iterate the EFI memory map in reverse order because the regions
687 * will be mapped top-down. The end result is the same as if we had
688 * mapped things forward, but doesn't require us to change the
689 * existing implementation of efi_map_region().
691 static inline void *efi_map_next_entry_reverse(void *entry
)
695 return efi
.memmap
.map_end
- efi
.memmap
.desc_size
;
697 entry
-= efi
.memmap
.desc_size
;
698 if (entry
< efi
.memmap
.map
)
705 * efi_map_next_entry - Return the next EFI memory map descriptor
706 * @entry: Previous EFI memory map descriptor
708 * This is a helper function to iterate over the EFI memory map, which
709 * we do in different orders depending on the current configuration.
711 * To begin traversing the memory map @entry must be %NULL.
713 * Returns %NULL when we reach the end of the memory map.
715 static void *efi_map_next_entry(void *entry
)
717 if (!efi_enabled(EFI_OLD_MEMMAP
) && efi_enabled(EFI_64BIT
)) {
719 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
720 * config table feature requires us to map all entries
721 * in the same order as they appear in the EFI memory
722 * map. That is to say, entry N must have a lower
723 * virtual address than entry N+1. This is because the
724 * firmware toolchain leaves relative references in
725 * the code/data sections, which are split and become
726 * separate EFI memory regions. Mapping things
727 * out-of-order leads to the firmware accessing
728 * unmapped addresses.
730 * Since we need to map things this way whether or not
731 * the kernel actually makes use of
732 * EFI_PROPERTIES_TABLE, let's just switch to this
733 * scheme by default for 64-bit.
735 return efi_map_next_entry_reverse(entry
);
740 return efi
.memmap
.map
;
742 entry
+= efi
.memmap
.desc_size
;
743 if (entry
>= efi
.memmap
.map_end
)
750 * Map the efi memory ranges of the runtime services and update new_mmap with
753 static void * __init
efi_map_regions(int *count
, int *pg_shift
)
755 void *p
, *new_memmap
= NULL
;
756 unsigned long left
= 0;
757 unsigned long desc_size
;
758 efi_memory_desc_t
*md
;
760 desc_size
= efi
.memmap
.desc_size
;
763 while ((p
= efi_map_next_entry(p
))) {
765 if (!(md
->attribute
& EFI_MEMORY_RUNTIME
)) {
767 if (md
->type
!= EFI_BOOT_SERVICES_CODE
&&
768 md
->type
!= EFI_BOOT_SERVICES_DATA
)
774 get_systab_virt_addr(md
);
776 if (left
< desc_size
) {
777 new_memmap
= realloc_pages(new_memmap
, *pg_shift
);
781 left
+= PAGE_SIZE
<< *pg_shift
;
785 memcpy(new_memmap
+ (*count
* desc_size
), md
, desc_size
);
794 static void __init
kexec_enter_virtual_mode(void)
796 #ifdef CONFIG_KEXEC_CORE
797 efi_memory_desc_t
*md
;
798 unsigned int num_pages
;
803 * We don't do virtual mode, since we don't do runtime services, on
806 if (!efi_is_native()) {
808 clear_bit(EFI_RUNTIME_SERVICES
, &efi
.flags
);
812 if (efi_alloc_page_tables()) {
813 pr_err("Failed to allocate EFI page tables\n");
814 clear_bit(EFI_RUNTIME_SERVICES
, &efi
.flags
);
819 * Map efi regions which were passed via setup_data. The virt_addr is a
820 * fixed addr which was used in first kernel of a kexec boot.
822 for_each_efi_memory_desc(md
) {
823 efi_map_region_fixed(md
); /* FIXME: add error handling */
824 get_systab_virt_addr(md
);
831 num_pages
= ALIGN(efi
.memmap
.nr_map
* efi
.memmap
.desc_size
, PAGE_SIZE
);
832 num_pages
>>= PAGE_SHIFT
;
834 if (efi_setup_page_tables(efi
.memmap
.phys_map
, num_pages
)) {
835 clear_bit(EFI_RUNTIME_SERVICES
, &efi
.flags
);
839 efi_sync_low_kernel_mappings();
842 * Now that EFI is in virtual mode, update the function
843 * pointers in the runtime service table to the new virtual addresses.
845 * Call EFI services through wrapper functions.
847 efi
.runtime_version
= efi_systab
.hdr
.revision
;
849 efi_native_runtime_setup();
851 efi
.set_virtual_address_map
= NULL
;
853 if (efi_enabled(EFI_OLD_MEMMAP
) && (__supported_pte_mask
& _PAGE_NX
))
854 runtime_code_page_mkexec();
856 /* clean DUMMY object */
857 efi_delete_dummy_variable();
862 * This function will switch the EFI runtime services to virtual mode.
863 * Essentially, we look through the EFI memmap and map every region that
864 * has the runtime attribute bit set in its memory descriptor into the
865 * efi_pgd page table.
867 * The old method which used to update that memory descriptor with the
868 * virtual address obtained from ioremap() is still supported when the
869 * kernel is booted with efi=old_map on its command line. Same old
870 * method enabled the runtime services to be called without having to
871 * thunk back into physical mode for every invocation.
873 * The new method does a pagetable switch in a preemption-safe manner
874 * so that we're in a different address space when calling a runtime
875 * function. For function arguments passing we do copy the PUDs of the
876 * kernel page table into efi_pgd prior to each call.
878 * Specially for kexec boot, efi runtime maps in previous kernel should
879 * be passed in via setup_data. In that case runtime ranges will be mapped
880 * to the same virtual addresses as the first kernel, see
881 * kexec_enter_virtual_mode().
883 static void __init
__efi_enter_virtual_mode(void)
885 int count
= 0, pg_shift
= 0;
886 void *new_memmap
= NULL
;
891 if (efi_alloc_page_tables()) {
892 pr_err("Failed to allocate EFI page tables\n");
893 clear_bit(EFI_RUNTIME_SERVICES
, &efi
.flags
);
898 new_memmap
= efi_map_regions(&count
, &pg_shift
);
900 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
901 clear_bit(EFI_RUNTIME_SERVICES
, &efi
.flags
);
909 if (efi_setup_page_tables(__pa(new_memmap
), 1 << pg_shift
)) {
910 clear_bit(EFI_RUNTIME_SERVICES
, &efi
.flags
);
914 efi_sync_low_kernel_mappings();
916 if (efi_is_native()) {
917 status
= phys_efi_set_virtual_address_map(
918 efi
.memmap
.desc_size
* count
,
919 efi
.memmap
.desc_size
,
920 efi
.memmap
.desc_version
,
921 (efi_memory_desc_t
*)__pa(new_memmap
));
923 status
= efi_thunk_set_virtual_address_map(
924 efi_phys
.set_virtual_address_map
,
925 efi
.memmap
.desc_size
* count
,
926 efi
.memmap
.desc_size
,
927 efi
.memmap
.desc_version
,
928 (efi_memory_desc_t
*)__pa(new_memmap
));
931 if (status
!= EFI_SUCCESS
) {
932 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
934 panic("EFI call to SetVirtualAddressMap() failed!");
938 * Now that EFI is in virtual mode, update the function
939 * pointers in the runtime service table to the new virtual addresses.
941 * Call EFI services through wrapper functions.
943 efi
.runtime_version
= efi_systab
.hdr
.revision
;
946 efi_native_runtime_setup();
948 efi_thunk_runtime_setup();
950 efi
.set_virtual_address_map
= NULL
;
953 * Apply more restrictive page table mapping attributes now that
954 * SVAM() has been called and the firmware has performed all
955 * necessary relocation fixups for the new virtual addresses.
957 efi_runtime_update_mappings();
958 efi_dump_pagetable();
961 * We mapped the descriptor array into the EFI pagetable above
962 * but we're not unmapping it here because if we're running in
963 * EFI mixed mode we need all of memory to be accessible when
964 * we pass parameters to the EFI runtime services in the
967 free_pages((unsigned long)new_memmap
, pg_shift
);
969 /* clean DUMMY object */
970 efi_delete_dummy_variable();
973 void __init
efi_enter_virtual_mode(void)
975 if (efi_enabled(EFI_PARAVIRT
))
979 kexec_enter_virtual_mode();
981 __efi_enter_virtual_mode();
985 * Convenience functions to obtain memory types and attributes
987 u32
efi_mem_type(unsigned long phys_addr
)
989 efi_memory_desc_t
*md
;
991 if (!efi_enabled(EFI_MEMMAP
))
994 for_each_efi_memory_desc(md
) {
995 if ((md
->phys_addr
<= phys_addr
) &&
996 (phys_addr
< (md
->phys_addr
+
997 (md
->num_pages
<< EFI_PAGE_SHIFT
))))
1003 static int __init
arch_parse_efi_cmdline(char *str
)
1006 pr_warn("need at least one option\n");
1010 if (parse_option_str(str
, "old_map"))
1011 set_bit(EFI_OLD_MEMMAP
, &efi
.flags
);
1015 early_param("efi", arch_parse_efi_cmdline
);