efi/arm64: Fix fdt-related memory reservation
authorMark Salter <msalter@redhat.com>
Mon, 8 Sep 2014 17:01:08 +0000 (13:01 -0400)
committerMatt Fleming <matt.fleming@intel.com>
Tue, 9 Sep 2014 06:51:09 +0000 (07:51 +0100)
commit0ceac9e094b065fe3fec19669740f338d3480498
tree13c1130bd8946b473214ac173019e45809340727
parent9cb0e394234d244fe5a97e743ec9dd7ddff7e64b
efi/arm64: Fix fdt-related memory reservation

Commit 86c8b27a01cf:
 "arm64: ignore DT memreserve entries when booting in UEFI mode

prevents early_init_fdt_scan_reserved_mem() from being called for
arm64 kernels booting via UEFI. This was done because the kernel
will use the UEFI memory map to determine reserved memory regions.
That approach has problems in that early_init_fdt_scan_reserved_mem()
also reserves the FDT itself and any node-specific reserved memory.
By chance of some kernel configs, the FDT may be overwritten before
it can be unflattened and the kernel will fail to boot. More subtle
problems will result if the FDT has node specific reserved memory
which is not really reserved.

This patch has the UEFI stub remove the memory reserve map entries
from the FDT as it does with the memory nodes. This allows
early_init_fdt_scan_reserved_mem() to be called unconditionally
so that the other needed reservations are made.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
arch/arm64/mm/init.c
drivers/firmware/efi/libstub/fdt.c