Commit 7fe5d2b1 authored Jan 15, 2015 by Ard Biesheuvel Committed by Catalin Marinas Jan 16, 2015

arm64/efi: handle potential failure to remap memory map



When remapping the UEFI memory map using ioremap_cache(), we
have to deal with potential failure. Note that, even if the
common case is for ioremap_cache() to return the existing linear
mapping of the memory map, we cannot rely on that to be always the
case, e.g., in the presence of a mem= kernel parameter.

At the same time, remove a stale comment and move the memmap code
together.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent d67703a8

arch/arm64/kernel/efi.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -229,19 +229,21 @@ static int __init arm64_enable_runtime_services(void)
		return -1;
		}

		mapsize = memmap.map_end - memmap.map;

		if (efi_runtime_disabled()) {
		pr_info("EFI runtime services will be disabled.\n");
		return -1;
		}

		pr_info("Remapping and enabling EFI services.\n");
		/* replace early memmap mapping with permanent mapping */

		mapsize = memmap.map_end - memmap.map;
		memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
		mapsize);
		if (!memmap.map) {
		pr_err("Failed to remap EFI memory map\n");
		return -1;
		}
		memmap.map_end = memmap.map + mapsize;

		efi.memmap = &memmap;

		efi.systab = (__force void *)ioremap_cache(efi_system_table,

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