x86: reserve EFI memory map with reserve_early

This patch reserves the EFI memory map with reserve_early(). Because EFI
memory map is allocated by bootloader, if it is not reserved by
reserved_early(), it may be overwritten through address returned by
find_e820_area().

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: andi@firstfloor.org
Cc: mingo@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 20 insertions, 13 deletions

diff --git a/arch/x86/kernel/efi.c b/arch/x86/kernel/efi.c
index 4a1a26d5931f..d5c7fcdd1861 100644
--- a/arch/x86/kernel/efi.c
+++ b/arch/x86/kernel/efi.c
@@ -238,6 +238,23 @@ static void __init add_efi_memmap(void)
         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 }
 
+void __init efi_reserve_early(void)
+{
+        unsigned long pmap;
+
+        pmap = boot_params.efi_info.efi_memmap;
+#ifdef CONFIG_X86_64
+        pmap += (__u64)boot_params.efi_info.efi_memmap_hi << 32;
+#endif
+        memmap.phys_map = (void *)pmap;
+        memmap.nr_map = boot_params.efi_info.efi_memmap_size /
+                boot_params.efi_info.efi_memdesc_size;
+        memmap.desc_version = boot_params.efi_info.efi_memdesc_version;
+        memmap.desc_size = boot_params.efi_info.efi_memdesc_size;
+        reserve_early(pmap, pmap + memmap.nr_map * memmap.desc_size,
+                      "EFI memmap");
+}
+
 #if EFI_DEBUG
 static void __init print_efi_memmap(void)
 {
@@ -267,21 +284,11 @@ void __init efi_init(void)
         int i = 0;
         void *tmp;
 
-#ifdef CONFIG_X86_32
         efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
-        memmap.phys_map = (void *)boot_params.efi_info.efi_memmap;
-#else
-        efi_phys.systab = (efi_system_table_t *)
-                (boot_params.efi_info.efi_systab |
-                 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
-        memmap.phys_map = (void *)
-                (boot_params.efi_info.efi_memmap |
-                 ((__u64)boot_params.efi_info.efi_memmap_hi<<32));
+#ifdef CONFIG_X86_64
+        efi_phys.systab = (void *)efi_phys.systab +
+                ((__u64)boot_params.efi_info.efi_systab_hi<<32);
 #endif
-        memmap.nr_map = boot_params.efi_info.efi_memmap_size /
-                boot_params.efi_info.efi_memdesc_size;
-        memmap.desc_version = boot_params.efi_info.efi_memdesc_version;
-        memmap.desc_size = boot_params.efi_info.efi_memdesc_size;
 
         efi.systab = early_ioremap((unsigned long)efi_phys.systab,
                                    sizeof(efi_system_table_t));