[coreboot-gerrit] Patch merged into coreboot/master: arm64: mmu: Prevent CPU prefetch instructions from device memory

the following patch was just integrated into master:
commit c159a0ec4a41a4243df60a1a94c1d4848f6492c5
Author: Jimmy Huang 
Date:   Tue Sep 15 15:29:10 2015 +0800

arm64: mmu: Prevent CPU prefetch instructions from device memory

Set XN bit of block upper attribute to device memory in mmu. CPU may
    speculatively prefetch instructions from device memory, but the IO
    subsystem of some implementation may not support this operation. Set
    this attribute to device memory mmu entries can prevent CPU from
    prefetching device memory.

BRANCH=none
    BUG=none
    TEST=build and booted to kernel on oak-rev3 with dcm enabled.

Change-Id: I52ac7d7c84220624aaf6a48d64b9110d7afeb293
    Signed-off-by: Patrick Georgi 
    Original-Commit-Id: 7b01a4157cb046a5e75ea7625060a602e7a63c3c
    Original-Change-Id: Id535e990a23b6c89123b5a4e64d7ed21eebed607
    Original-Signed-off-by: Jimmy Huang 
    Original-Reviewed-on: https://chromium-review.googlesource.com/302301
    Original-Commit-Ready: Yidi Lin 
    Original-Tested-by: Yidi Lin 
    Original-Reviewed-by: Aaron Durbin 
    Original-Reviewed-by: Julius Werner 
    Reviewed-on: http://review.coreboot.org/11722
    Tested-by: build bot (Jenkins)
    Reviewed-by: Patrick Georgi

See http://review.coreboot.org/11722 for details.

-gerrit