From: Will Deacon <will.deacon@arm.com>
Date: Mon, 23 Mar 2015 19:07:02 +0000 (+0000)
Subject: arm64: errata: add workaround for cortex-a53 erratum #845719
X-Git-Tag: omap-for-v4.2/o2_dc~115^2~1
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=905e8c5dcaa147163672b06fe9dcb5abaacbc711;p=pandora-kernel.git

arm64: errata: add workaround for cortex-a53 erratum #845719

When running a compat (AArch32) userspace on Cortex-A53, a load at EL0
from a virtual address that matches the bottom 32 bits of the virtual
address used by a recent load at (AArch64) EL1 might return incorrect
data.

This patch works around the issue by writing to the contextidr_el1
register on the exception return path when returning to a 32-bit task.
This workaround is patched in at runtime based on the MIDR value of the
processor.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---

Reading git-diff-tree failed