arm64/efi: mark UEFI reserved regions as MEMBLOCK_NOMAP

Change the EFI memory reservation logic to use memblock_mark_nomap()
rather than memblock_reserve() to mark UEFI reserved regions as
occupied. In addition to reserving them against allocations done by
memblock, this will also prevent them from being covered by the linear
mapping.

Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 4eeb17198cfa..04531d35f1df 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -187,7 +187,7 @@ static __init void reserve_regions(void)
                         early_init_dt_add_memory_arch(paddr, size);
 
                 if (is_reserve_region(md)) {
-                        memblock_reserve(paddr, size);
+                        memblock_mark_nomap(paddr, size);
                         if (efi_enabled(EFI_DBG))
                                 pr_cont("*");
                 }
@@ -209,8 +209,6 @@ void __init efi_init(void)
 
         efi_system_table = params.system_table;
 
-        memblock_reserve(params.mmap & PAGE_MASK,
-                         PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
         memmap.phys_map = params.mmap;
         memmap.map = early_memremap(params.mmap, params.mmap_size);
         if (memmap.map == NULL) {
@@ -230,6 +228,9 @@ void __init efi_init(void)
 
         reserve_regions();
         early_memunmap(memmap.map, params.mmap_size);
+        memblock_mark_nomap(params.mmap & PAGE_MASK,
+                            PAGE_ALIGN(params.mmap_size +
+                                       (params.mmap & ~PAGE_MASK)));
 }
 
 static bool __init efi_virtmap_init(void)