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 struct efi_memory_map memmap
;
61 static struct efi efi_phys __initdata
;
62 static efi_system_table_t efi_systab __initdata
;
64 static efi_config_table_type_t arch_tables
[] __initdata
= {
66 {UV_SYSTEM_TABLE_GUID
, "UVsystab", &efi
.uv_systab
},
68 {NULL_GUID
, NULL
, NULL
},
71 u64 efi_setup
; /* efi setup_data physical address */
73 static bool disable_runtime __initdata
= false;
74 static int __init
setup_noefi(char *arg
)
76 disable_runtime
= true;
79 early_param("noefi", setup_noefi
);
82 EXPORT_SYMBOL(add_efi_memmap
);
84 static int __init
setup_add_efi_memmap(char *arg
)
89 early_param("add_efi_memmap", setup_add_efi_memmap
);
91 static efi_status_t __init
phys_efi_set_virtual_address_map(
92 unsigned long memory_map_size
,
93 unsigned long descriptor_size
,
94 u32 descriptor_version
,
95 efi_memory_desc_t
*virtual_map
)
99 efi_call_phys_prelog();
100 status
= efi_call_phys(efi_phys
.set_virtual_address_map
,
101 memory_map_size
, descriptor_size
,
102 descriptor_version
, virtual_map
);
103 efi_call_phys_epilog();
107 void efi_get_time(struct timespec
*now
)
113 status
= efi
.get_time(&eft
, &cap
);
114 if (status
!= EFI_SUCCESS
)
115 pr_err("Oops: efitime: can't read time!\n");
117 now
->tv_sec
= mktime(eft
.year
, eft
.month
, eft
.day
, eft
.hour
,
118 eft
.minute
, eft
.second
);
123 * Tell the kernel about the EFI memory map. This might include
124 * more than the max 128 entries that can fit in the e820 legacy
125 * (zeropage) memory map.
128 static void __init
do_add_efi_memmap(void)
132 for (p
= memmap
.map
; p
< memmap
.map_end
; p
+= memmap
.desc_size
) {
133 efi_memory_desc_t
*md
= p
;
134 unsigned long long start
= md
->phys_addr
;
135 unsigned long long size
= md
->num_pages
<< EFI_PAGE_SHIFT
;
139 case EFI_LOADER_CODE
:
140 case EFI_LOADER_DATA
:
141 case EFI_BOOT_SERVICES_CODE
:
142 case EFI_BOOT_SERVICES_DATA
:
143 case EFI_CONVENTIONAL_MEMORY
:
144 if (md
->attribute
& EFI_MEMORY_WB
)
145 e820_type
= E820_RAM
;
147 e820_type
= E820_RESERVED
;
149 case EFI_ACPI_RECLAIM_MEMORY
:
150 e820_type
= E820_ACPI
;
152 case EFI_ACPI_MEMORY_NVS
:
153 e820_type
= E820_NVS
;
155 case EFI_UNUSABLE_MEMORY
:
156 e820_type
= E820_UNUSABLE
;
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
;
177 if (efi_enabled(EFI_PARAVIRT
))
181 /* Can't handle data above 4GB at this time */
182 if (e
->efi_memmap_hi
) {
183 pr_err("Memory map is above 4GB, disabling EFI.\n");
186 pmap
= e
->efi_memmap
;
188 pmap
= (e
->efi_memmap
| ((__u64
)e
->efi_memmap_hi
<< 32));
190 memmap
.phys_map
= (void *)pmap
;
191 memmap
.nr_map
= e
->efi_memmap_size
/
193 memmap
.desc_size
= e
->efi_memdesc_size
;
194 memmap
.desc_version
= e
->efi_memdesc_version
;
196 memblock_reserve(pmap
, memmap
.nr_map
* memmap
.desc_size
);
198 efi
.memmap
= &memmap
;
203 static void __init
print_efi_memmap(void)
206 efi_memory_desc_t
*md
;
210 for (p
= memmap
.map
, i
= 0;
212 p
+= memmap
.desc_size
, i
++) {
214 pr_info("mem%02u: type=%u, attr=0x%llx, range=[0x%016llx-0x%016llx) (%lluMB)\n",
215 i
, md
->type
, md
->attribute
, md
->phys_addr
,
216 md
->phys_addr
+ (md
->num_pages
<< EFI_PAGE_SHIFT
),
217 (md
->num_pages
>> (20 - EFI_PAGE_SHIFT
)));
219 #endif /* EFI_DEBUG */
222 void __init
efi_unmap_memmap(void)
224 clear_bit(EFI_MEMMAP
, &efi
.flags
);
226 early_memunmap(memmap
.map
, memmap
.nr_map
* memmap
.desc_size
);
231 static int __init
efi_systab_init(void *phys
)
233 if (efi_enabled(EFI_64BIT
)) {
234 efi_system_table_64_t
*systab64
;
235 struct efi_setup_data
*data
= NULL
;
239 data
= early_memremap(efi_setup
, sizeof(*data
));
243 systab64
= early_memremap((unsigned long)phys
,
245 if (systab64
== NULL
) {
246 pr_err("Couldn't map the system table!\n");
248 early_memunmap(data
, sizeof(*data
));
252 efi_systab
.hdr
= systab64
->hdr
;
253 efi_systab
.fw_vendor
= data
? (unsigned long)data
->fw_vendor
:
255 tmp
|= data
? data
->fw_vendor
: systab64
->fw_vendor
;
256 efi_systab
.fw_revision
= systab64
->fw_revision
;
257 efi_systab
.con_in_handle
= systab64
->con_in_handle
;
258 tmp
|= systab64
->con_in_handle
;
259 efi_systab
.con_in
= systab64
->con_in
;
260 tmp
|= systab64
->con_in
;
261 efi_systab
.con_out_handle
= systab64
->con_out_handle
;
262 tmp
|= systab64
->con_out_handle
;
263 efi_systab
.con_out
= systab64
->con_out
;
264 tmp
|= systab64
->con_out
;
265 efi_systab
.stderr_handle
= systab64
->stderr_handle
;
266 tmp
|= systab64
->stderr_handle
;
267 efi_systab
.stderr
= systab64
->stderr
;
268 tmp
|= systab64
->stderr
;
269 efi_systab
.runtime
= data
?
270 (void *)(unsigned long)data
->runtime
:
271 (void *)(unsigned long)systab64
->runtime
;
272 tmp
|= data
? data
->runtime
: systab64
->runtime
;
273 efi_systab
.boottime
= (void *)(unsigned long)systab64
->boottime
;
274 tmp
|= systab64
->boottime
;
275 efi_systab
.nr_tables
= systab64
->nr_tables
;
276 efi_systab
.tables
= data
? (unsigned long)data
->tables
:
278 tmp
|= data
? data
->tables
: systab64
->tables
;
280 early_memunmap(systab64
, sizeof(*systab64
));
282 early_memunmap(data
, sizeof(*data
));
285 pr_err("EFI data located above 4GB, disabling EFI.\n");
290 efi_system_table_32_t
*systab32
;
292 systab32
= early_memremap((unsigned long)phys
,
294 if (systab32
== NULL
) {
295 pr_err("Couldn't map the system table!\n");
299 efi_systab
.hdr
= systab32
->hdr
;
300 efi_systab
.fw_vendor
= systab32
->fw_vendor
;
301 efi_systab
.fw_revision
= systab32
->fw_revision
;
302 efi_systab
.con_in_handle
= systab32
->con_in_handle
;
303 efi_systab
.con_in
= systab32
->con_in
;
304 efi_systab
.con_out_handle
= systab32
->con_out_handle
;
305 efi_systab
.con_out
= systab32
->con_out
;
306 efi_systab
.stderr_handle
= systab32
->stderr_handle
;
307 efi_systab
.stderr
= systab32
->stderr
;
308 efi_systab
.runtime
= (void *)(unsigned long)systab32
->runtime
;
309 efi_systab
.boottime
= (void *)(unsigned long)systab32
->boottime
;
310 efi_systab
.nr_tables
= systab32
->nr_tables
;
311 efi_systab
.tables
= systab32
->tables
;
313 early_memunmap(systab32
, sizeof(*systab32
));
316 efi
.systab
= &efi_systab
;
319 * Verify the EFI Table
321 if (efi
.systab
->hdr
.signature
!= EFI_SYSTEM_TABLE_SIGNATURE
) {
322 pr_err("System table signature incorrect!\n");
325 if ((efi
.systab
->hdr
.revision
>> 16) == 0)
326 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
327 efi
.systab
->hdr
.revision
>> 16,
328 efi
.systab
->hdr
.revision
& 0xffff);
330 set_bit(EFI_SYSTEM_TABLES
, &efi
.flags
);
335 static int __init
efi_runtime_init32(void)
337 efi_runtime_services_32_t
*runtime
;
339 runtime
= early_memremap((unsigned long)efi
.systab
->runtime
,
340 sizeof(efi_runtime_services_32_t
));
342 pr_err("Could not map the runtime service table!\n");
347 * We will only need *early* access to the following two
348 * EFI runtime services before set_virtual_address_map
351 efi_phys
.set_virtual_address_map
=
352 (efi_set_virtual_address_map_t
*)
353 (unsigned long)runtime
->set_virtual_address_map
;
354 early_memunmap(runtime
, sizeof(efi_runtime_services_32_t
));
359 static int __init
efi_runtime_init64(void)
361 efi_runtime_services_64_t
*runtime
;
363 runtime
= early_memremap((unsigned long)efi
.systab
->runtime
,
364 sizeof(efi_runtime_services_64_t
));
366 pr_err("Could not map the runtime service table!\n");
371 * We will only need *early* access to the following two
372 * EFI runtime services before set_virtual_address_map
375 efi_phys
.set_virtual_address_map
=
376 (efi_set_virtual_address_map_t
*)
377 (unsigned long)runtime
->set_virtual_address_map
;
378 early_memunmap(runtime
, sizeof(efi_runtime_services_64_t
));
383 static int __init
efi_runtime_init(void)
388 * Check out the runtime services table. We need to map
389 * the runtime services table so that we can grab the physical
390 * address of several of the EFI runtime functions, needed to
391 * set the firmware into virtual mode.
393 * When EFI_PARAVIRT is in force then we could not map runtime
394 * service memory region because we do not have direct access to it.
395 * However, runtime services are available through proxy functions
396 * (e.g. in case of Xen dom0 EFI implementation they call special
397 * hypercall which executes relevant EFI functions) and that is why
398 * they are always enabled.
401 if (!efi_enabled(EFI_PARAVIRT
)) {
402 if (efi_enabled(EFI_64BIT
))
403 rv
= efi_runtime_init64();
405 rv
= efi_runtime_init32();
411 set_bit(EFI_RUNTIME_SERVICES
, &efi
.flags
);
416 static int __init
efi_memmap_init(void)
418 if (efi_enabled(EFI_PARAVIRT
))
421 /* Map the EFI memory map */
422 memmap
.map
= early_memremap((unsigned long)memmap
.phys_map
,
423 memmap
.nr_map
* memmap
.desc_size
);
424 if (memmap
.map
== NULL
) {
425 pr_err("Could not map the memory map!\n");
428 memmap
.map_end
= memmap
.map
+ (memmap
.nr_map
* memmap
.desc_size
);
433 set_bit(EFI_MEMMAP
, &efi
.flags
);
438 void __init
efi_init(void)
441 char vendor
[100] = "unknown";
446 if (boot_params
.efi_info
.efi_systab_hi
||
447 boot_params
.efi_info
.efi_memmap_hi
) {
448 pr_info("Table located above 4GB, disabling EFI.\n");
451 efi_phys
.systab
= (efi_system_table_t
*)boot_params
.efi_info
.efi_systab
;
453 efi_phys
.systab
= (efi_system_table_t
*)
454 (boot_params
.efi_info
.efi_systab
|
455 ((__u64
)boot_params
.efi_info
.efi_systab_hi
<<32));
458 if (efi_systab_init(efi_phys
.systab
))
461 efi
.config_table
= (unsigned long)efi
.systab
->tables
;
462 efi
.fw_vendor
= (unsigned long)efi
.systab
->fw_vendor
;
463 efi
.runtime
= (unsigned long)efi
.systab
->runtime
;
466 * Show what we know for posterity
468 c16
= tmp
= early_memremap(efi
.systab
->fw_vendor
, 2);
470 for (i
= 0; i
< sizeof(vendor
) - 1 && *c16
; ++i
)
474 pr_err("Could not map the firmware vendor!\n");
475 early_memunmap(tmp
, 2);
477 pr_info("EFI v%u.%.02u by %s\n",
478 efi
.systab
->hdr
.revision
>> 16,
479 efi
.systab
->hdr
.revision
& 0xffff, vendor
);
481 if (efi_reuse_config(efi
.systab
->tables
, efi
.systab
->nr_tables
))
484 if (efi_config_init(arch_tables
))
488 * Note: We currently don't support runtime services on an EFI
489 * that doesn't match the kernel 32/64-bit mode.
492 if (!efi_runtime_supported())
493 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
495 if (disable_runtime
|| efi_runtime_init())
498 if (efi_memmap_init())
504 void __init
efi_late_init(void)
509 void __init
efi_set_executable(efi_memory_desc_t
*md
, bool executable
)
513 addr
= md
->virt_addr
;
514 npages
= md
->num_pages
;
516 memrange_efi_to_native(&addr
, &npages
);
519 set_memory_x(addr
, npages
);
521 set_memory_nx(addr
, npages
);
524 void __init
runtime_code_page_mkexec(void)
526 efi_memory_desc_t
*md
;
529 /* Make EFI runtime service code area executable */
530 for (p
= memmap
.map
; p
< memmap
.map_end
; p
+= memmap
.desc_size
) {
533 if (md
->type
!= EFI_RUNTIME_SERVICES_CODE
)
536 efi_set_executable(md
, true);
540 void efi_memory_uc(u64 addr
, unsigned long size
)
542 unsigned long page_shift
= 1UL << EFI_PAGE_SHIFT
;
545 npages
= round_up(size
, page_shift
) / page_shift
;
546 memrange_efi_to_native(&addr
, &npages
);
547 set_memory_uc(addr
, npages
);
550 void __init
old_map_region(efi_memory_desc_t
*md
)
552 u64 start_pfn
, end_pfn
, end
;
556 start_pfn
= PFN_DOWN(md
->phys_addr
);
557 size
= md
->num_pages
<< PAGE_SHIFT
;
558 end
= md
->phys_addr
+ size
;
559 end_pfn
= PFN_UP(end
);
561 if (pfn_range_is_mapped(start_pfn
, end_pfn
)) {
562 va
= __va(md
->phys_addr
);
564 if (!(md
->attribute
& EFI_MEMORY_WB
))
565 efi_memory_uc((u64
)(unsigned long)va
, size
);
567 va
= efi_ioremap(md
->phys_addr
, size
,
568 md
->type
, md
->attribute
);
570 md
->virt_addr
= (u64
) (unsigned long) va
;
572 pr_err("ioremap of 0x%llX failed!\n",
573 (unsigned long long)md
->phys_addr
);
576 /* Merge contiguous regions of the same type and attribute */
577 static void __init
efi_merge_regions(void)
580 efi_memory_desc_t
*md
, *prev_md
= NULL
;
582 for (p
= memmap
.map
; p
< memmap
.map_end
; p
+= memmap
.desc_size
) {
591 if (prev_md
->type
!= md
->type
||
592 prev_md
->attribute
!= md
->attribute
) {
597 prev_size
= prev_md
->num_pages
<< EFI_PAGE_SHIFT
;
599 if (md
->phys_addr
== (prev_md
->phys_addr
+ prev_size
)) {
600 prev_md
->num_pages
+= md
->num_pages
;
601 md
->type
= EFI_RESERVED_TYPE
;
609 static void __init
get_systab_virt_addr(efi_memory_desc_t
*md
)
614 size
= md
->num_pages
<< EFI_PAGE_SHIFT
;
615 end
= md
->phys_addr
+ size
;
616 systab
= (u64
)(unsigned long)efi_phys
.systab
;
617 if (md
->phys_addr
<= systab
&& systab
< end
) {
618 systab
+= md
->virt_addr
- md
->phys_addr
;
619 efi
.systab
= (efi_system_table_t
*)(unsigned long)systab
;
623 static void __init
save_runtime_map(void)
626 efi_memory_desc_t
*md
;
627 void *tmp
, *p
, *q
= NULL
;
630 if (efi_enabled(EFI_OLD_MEMMAP
))
633 for (p
= memmap
.map
; p
< memmap
.map_end
; p
+= memmap
.desc_size
) {
636 if (!(md
->attribute
& EFI_MEMORY_RUNTIME
) ||
637 (md
->type
== EFI_BOOT_SERVICES_CODE
) ||
638 (md
->type
== EFI_BOOT_SERVICES_DATA
))
640 tmp
= krealloc(q
, (count
+ 1) * memmap
.desc_size
, GFP_KERNEL
);
645 memcpy(q
+ count
* memmap
.desc_size
, md
, memmap
.desc_size
);
649 efi_runtime_map_setup(q
, count
, memmap
.desc_size
);
654 pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
658 static void *realloc_pages(void *old_memmap
, int old_shift
)
662 ret
= (void *)__get_free_pages(GFP_KERNEL
, old_shift
+ 1);
667 * A first-time allocation doesn't have anything to copy.
672 memcpy(ret
, old_memmap
, PAGE_SIZE
<< old_shift
);
675 free_pages((unsigned long)old_memmap
, old_shift
);
680 * Map the efi memory ranges of the runtime services and update new_mmap with
683 static void * __init
efi_map_regions(int *count
, int *pg_shift
)
685 void *p
, *new_memmap
= NULL
;
686 unsigned long left
= 0;
687 efi_memory_desc_t
*md
;
689 for (p
= memmap
.map
; p
< memmap
.map_end
; p
+= memmap
.desc_size
) {
691 if (!(md
->attribute
& EFI_MEMORY_RUNTIME
)) {
693 if (md
->type
!= EFI_BOOT_SERVICES_CODE
&&
694 md
->type
!= EFI_BOOT_SERVICES_DATA
)
700 get_systab_virt_addr(md
);
702 if (left
< memmap
.desc_size
) {
703 new_memmap
= realloc_pages(new_memmap
, *pg_shift
);
707 left
+= PAGE_SIZE
<< *pg_shift
;
711 memcpy(new_memmap
+ (*count
* memmap
.desc_size
), md
,
714 left
-= memmap
.desc_size
;
721 static void __init
kexec_enter_virtual_mode(void)
724 efi_memory_desc_t
*md
;
730 * We don't do virtual mode, since we don't do runtime services, on
733 if (!efi_is_native()) {
739 * Map efi regions which were passed via setup_data. The virt_addr is a
740 * fixed addr which was used in first kernel of a kexec boot.
742 for (p
= memmap
.map
; p
< memmap
.map_end
; p
+= memmap
.desc_size
) {
744 efi_map_region_fixed(md
); /* FIXME: add error handling */
745 get_systab_virt_addr(md
);
752 efi_sync_low_kernel_mappings();
755 * Now that EFI is in virtual mode, update the function
756 * pointers in the runtime service table to the new virtual addresses.
758 * Call EFI services through wrapper functions.
760 efi
.runtime_version
= efi_systab
.hdr
.revision
;
762 efi_native_runtime_setup();
764 efi
.set_virtual_address_map
= NULL
;
766 if (efi_enabled(EFI_OLD_MEMMAP
) && (__supported_pte_mask
& _PAGE_NX
))
767 runtime_code_page_mkexec();
769 /* clean DUMMY object */
770 efi_delete_dummy_variable();
775 * This function will switch the EFI runtime services to virtual mode.
776 * Essentially, we look through the EFI memmap and map every region that
777 * has the runtime attribute bit set in its memory descriptor into the
778 * ->trampoline_pgd page table using a top-down VA allocation scheme.
780 * The old method which used to update that memory descriptor with the
781 * virtual address obtained from ioremap() is still supported when the
782 * kernel is booted with efi=old_map on its command line. Same old
783 * method enabled the runtime services to be called without having to
784 * thunk back into physical mode for every invocation.
786 * The new method does a pagetable switch in a preemption-safe manner
787 * so that we're in a different address space when calling a runtime
788 * function. For function arguments passing we do copy the PGDs of the
789 * kernel page table into ->trampoline_pgd prior to each call.
791 * Specially for kexec boot, efi runtime maps in previous kernel should
792 * be passed in via setup_data. In that case runtime ranges will be mapped
793 * to the same virtual addresses as the first kernel, see
794 * kexec_enter_virtual_mode().
796 static void __init
__efi_enter_virtual_mode(void)
798 int count
= 0, pg_shift
= 0;
799 void *new_memmap
= NULL
;
805 new_memmap
= efi_map_regions(&count
, &pg_shift
);
807 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
815 if (efi_setup_page_tables(__pa(new_memmap
), 1 << pg_shift
))
818 efi_sync_low_kernel_mappings();
819 efi_dump_pagetable();
821 if (efi_is_native()) {
822 status
= phys_efi_set_virtual_address_map(
823 memmap
.desc_size
* count
,
826 (efi_memory_desc_t
*)__pa(new_memmap
));
828 status
= efi_thunk_set_virtual_address_map(
829 efi_phys
.set_virtual_address_map
,
830 memmap
.desc_size
* count
,
833 (efi_memory_desc_t
*)__pa(new_memmap
));
836 if (status
!= EFI_SUCCESS
) {
837 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
839 panic("EFI call to SetVirtualAddressMap() failed!");
843 * Now that EFI is in virtual mode, update the function
844 * pointers in the runtime service table to the new virtual addresses.
846 * Call EFI services through wrapper functions.
848 efi
.runtime_version
= efi_systab
.hdr
.revision
;
851 efi_native_runtime_setup();
853 efi_thunk_runtime_setup();
855 efi
.set_virtual_address_map
= NULL
;
857 efi_runtime_mkexec();
860 * We mapped the descriptor array into the EFI pagetable above but we're
861 * not unmapping it here. Here's why:
863 * We're copying select PGDs from the kernel page table to the EFI page
864 * table and when we do so and make changes to those PGDs like unmapping
865 * stuff from them, those changes appear in the kernel page table and we
868 * From setup_real_mode():
871 * trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
873 * In this particular case, our allocation is in PGD 0 of the EFI page
874 * table but we've copied that PGD from PGD[272] of the EFI page table:
876 * pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272
878 * where the direct memory mapping in kernel space is.
880 * new_memmap's VA comes from that direct mapping and thus clearing it,
881 * it would get cleared in the kernel page table too.
883 * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
885 free_pages((unsigned long)new_memmap
, pg_shift
);
887 /* clean DUMMY object */
888 efi_delete_dummy_variable();
891 void __init
efi_enter_virtual_mode(void)
893 if (efi_enabled(EFI_PARAVIRT
))
897 kexec_enter_virtual_mode();
899 __efi_enter_virtual_mode();
903 * Convenience functions to obtain memory types and attributes
905 u32
efi_mem_type(unsigned long phys_addr
)
907 efi_memory_desc_t
*md
;
910 if (!efi_enabled(EFI_MEMMAP
))
913 for (p
= memmap
.map
; p
< memmap
.map_end
; p
+= memmap
.desc_size
) {
915 if ((md
->phys_addr
<= phys_addr
) &&
916 (phys_addr
< (md
->phys_addr
+
917 (md
->num_pages
<< EFI_PAGE_SHIFT
))))
923 u64
efi_mem_attributes(unsigned long phys_addr
)
925 efi_memory_desc_t
*md
;
928 if (!efi_enabled(EFI_MEMMAP
))
931 for (p
= memmap
.map
; p
< memmap
.map_end
; p
+= memmap
.desc_size
) {
933 if ((md
->phys_addr
<= phys_addr
) &&
934 (phys_addr
< (md
->phys_addr
+
935 (md
->num_pages
<< EFI_PAGE_SHIFT
))))
936 return md
->attribute
;
941 static int __init
parse_efi_cmdline(char *str
)
946 if (!strncmp(str
, "old_map", 7))
947 set_bit(EFI_OLD_MEMMAP
, &efi
.flags
);
951 early_param("efi", parse_efi_cmdline
);