efi/arm*: Use memremap() to create the persistent memmap mapping

Instead of using ioremap_cache(), which is slightly inappropriate for
mapping firmware tables, and is not even allowed on ARM for mapping
regions that are covered by a struct page, use memremap(), which was
invented for this purpose, and will also reuse the existing kernel
direct mapping if the requested region is covered by it.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-10-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index 55a9ea041068426e23129b4564e6410794494a2b..19283deac375d76a8de6e59796c60b930186ea40 100644 (file)
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -105,8 +105,7 @@ static int __init arm_enable_runtime_services(void)
 
        mapsize = efi.memmap.map_end - efi.memmap.map;
 
-       efi.memmap.map = (__force void *)ioremap_cache(efi.memmap.phys_map,
-                                                      mapsize);
+       efi.memmap.map = memremap(efi.memmap.phys_map, mapsize, MEMREMAP_WB);
        if (!efi.memmap.map) {
                pr_err("Failed to remap EFI memory map\n");
                return -ENOMEM;