[PATCH v4 0/2] PPTT handle Handle architecturally unknown cache types

Jeffrey Hugo
2018-10-04T15:20:36Z

The ARM Architecture Reference Manual allows for caches to be "invisible" and
thus not specified in the system registers under some scenarios such as if the
cache cannot be managed by set/way operations.

However, such caches may be specified in the ACPI PPTT table for workload
performance/scheduling optimizations.

Currently such caches can cause an error in lscpu -

lscpu: cannot open /sys/devices/system/cpu/cpu0/cache/index3/type: No such
file or directory

and result in no output, providing a poor user experience. lstopo is also
affected as such caches are not included in the output.

Address these issues by attempting to be a little more discerning about when
cache information is provided to userspace, and also utilize all sources for
cache information when possible.

[v4]
-Collected all current tags and ammended to individual patches
-Removed PPTT_CHECKED_ATTRIBUTES

[v3]
-removed valid flag in PPTT
-Added Jeremy Linton's reviewed-by

[v2]
-Updated cacheinfo per Sudeep's suggestion
-Integrated the PPTT fix into existing PPTT code per Sudeep's suggestion

Jeffrey Hugo (2):
drivers: base: cacheinfo: Do not populate sysfs for unknown cache
types
ACPI/PPTT: Handle architecturally unknown cache types

drivers/acpi/pptt.c | 15 +++++++++++----
drivers/base/cacheinfo.c | 2 ++
2 files changed, 13 insertions(+), 4 deletions(-)