arm64: ignore DT memreserve entries when booting in UEFI mode

UEFI provides its own method for marking regions to reserve, via the
memory map which is also used to initialise memblock. So when using the
UEFI memory map, ignore any memreserve entries present in the DT.
Reported-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NLeif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arch/arm64/kernel/efi.c

@@ -188,6 +188,8 @@ static __init void reserve_regions(void)
 		if (uefi_debug)
 			pr_cont("\n");
 	}
+
+	set_bit(EFI_MEMMAP, &efi.flags);
 }
 
 

arch/arm64/mm/init.c

@@ -32,6 +32,7 @@
 #include <linux/of_fdt.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-contiguous.h>
+#include <linux/efi.h>
 
 #include <asm/fixmap.h>
 #include <asm/sections.h>
@@ -148,7 +149,8 @@ void __init arm64_memblock_init(void)
 		memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
 #endif
 
-	early_init_fdt_scan_reserved_mem();
+	if (!efi_enabled(EFI_MEMMAP))
+		early_init_fdt_scan_reserved_mem();
 
 	/* 4GB maximum for 32-bit only capable devices */
 	if (IS_ENABLED(CONFIG_ZONE_DMA))