arm64: efi: Add fake memory support

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4PM01
CVE: NA

--------------------------------

Fake memory map is used for faking memory's attribute values.
Commit 0f96a99d ("efi: Add "efi_fake_mem" boot option") introduce the
efi_fake_mem function. Now it can support arm64 with this patch.
For example you can mark 0-6G memory as EFI_MEMORY_MORE_RELIABLE by adding
efi_fake_mem=6G@0:0x10000 in the bootarg. You find more info about
fake memmap in kernel-parameters.txt.

Variable memstart_addr is only confirmed after arm64_memblock_init(). So
efi_fake_memmap() is needed to add after arm64_memblock_init().

Otherwise:

efi_memmap_alloc
   memblock_phys_alloc
     kmemleak_alloc_phys
        kmemleak_alloc(__va(phys), size, min_count, gfp);

this __va() will convert phys to a fault va and lead to a kmemleak error.
Signed-off-by: NMa Wupeng <mawupeng1@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

Documentation/admin-guide/kernel-parameters.txt

@@ -1290,7 +1290,7 @@
 			you are really sure that your UEFI does sane gc and
 			fulfills the spec otherwise your board may brick.
 
-	efi_fake_mem=	nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI; X86]
+	efi_fake_mem=	nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI; X86; ARM64]
 			Add arbitrary attribute to specific memory range by
 			updating original EFI memory map.
 			Region of memory which aa attribute is added to is

arch/arm64/kernel/setup.c

@@ -387,6 +387,8 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
 
 	arm64_memblock_init();
 
+	efi_fake_memmap();
+
 	paging_init();
 
 	acpi_table_upgrade();

drivers/firmware/efi/Kconfig

@@ -50,7 +50,7 @@ config EFI_RUNTIME_MAP
 
 config EFI_FAKE_MEMMAP
 	bool "Enable EFI fake memory map"
-	depends on EFI && X86
+	depends on EFI && (X86 || ARM64)
 	default n
 	help
 	  Saying Y here will enable "efi_fake_mem" boot option.