kernelconfig_penguin
CONFIG_ARM64_ERRATUM_2038923 is not available for the default architecture x86.
Result is shown for architecture arm64
depends
CONFIG_COMPILE_TEST

Cortex-A510: 2038923: workaround TRBE corruption with enable

configname: CONFIG_ARM64_ERRATUM_2038923

Linux Kernel Configuration
└─> Kernel Features
└─> ARM errata workarounds via the alternatives framework
└─> Cortex-A510: 2038923: workaround TRBE corruption with enable

This option adds the workaround for ARM Cortex-A510 erratum 2038923.

Affected Cortex-A510 core might cause an inconsistent view on whether trace is
prohibited within the CPU. As a result, the trace buffer or trace buffer state
might be corrupted. This happens after TRBE buffer has been enabled by setting
TRBLIMITR_EL1.E, followed by just a single context synchronization event before
execution changes from a context, in which trace is prohibited to one where it
isn't, or vice versa. In these mentioned conditions, the view of whether trace
is prohibited is inconsistent between parts of the CPU, and the trace buffer or
the trace buffer state might be corrupted.

Work around this in the driver by preventing an inconsistent view of whether the
trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
two ISB instructions if no ERET is to take place.

If unsure, say Y.