arm64: efi: Add fake memory support

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S
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.
Signed-off-by: NMa Wupeng <mawupeng1@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

Documentation/admin-guide/kernel-parameters.txt

@@ -1159,7 +1159,7 @@
 			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/mm/init.c

@@ -724,6 +724,9 @@ void __init arm64_memblock_init(void)
 	else
 		arm64_dma_phys_limit = PHYS_MASK + 1;
 
+	if (efi_enabled(EFI_MEMMAP))
+		efi_fake_memmap();
+
 	reserve_pin_memory_res();
 
 	/*

drivers/firmware/efi/Kconfig

@@ -54,7 +54,7 @@ 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.