From: jeremycline on
gitlab.com
Hi,
As part of the ongoing rebase effort, the following configuration
options need to be reviewed.
As a reminder, the ARK configuration flow involves moving unreviewed
configuration options from the pending directory to the ark directory.
In the diff below, options are removed from the pending directory and
added to the ark hierarchy. The final options that need to be ACKed
are the files that are being added to the ark hierarchy.
If the value for a file that is added should be changed, please reply
with a better option.
CONFIG_ARM64_ERRATUM_1508412:
This option adds a workaround for Arm Cortex-A77 erratum 1508412.
Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
of a store-exclusive or read of PAR_EL1 and a load with device or
non-cacheable memory attributes. The workaround depends on a firmware
counterpart.
KVM guests must also have the workaround implemented or they can
deadlock the system.
Work around the issue by inserting DMB SY barriers around PAR_EL1
register reads and warning KVM users. The DMB barrier is sufficient
to prevent a speculative PAR_EL1 read.
If unsure, say Y.
Symbol: ARM64_ERRATUM_1508412 [=y]
Type : bool
Defined at arch/arm64/Kconfig:639
Prompt: Cortex-A77: 1508412: workaround deadlock on sequence of
NC/Device load and store exclusive or PAR read
Location:
-> Kernel Features
-> ARM errata workarounds via the alternatives framework
---
Cc: Mark Salter <msalter(a)redhat.com>
Signed-off-by: Fedora Kernel Team <kernel-team(a)fedoraproject.org>