This series is to enable AUX pause and resume on Arm CoreSight.
The first patch extracts the trace unit controlling operations to two functions. These two functions will be used by AUX pause and resume.
Patches 02 and 03 change the ETMv4 driver to prepare callback functions for AUX pause and resume.
Patch 04 changes the ETM perf layer to support AUX pause and resume in a perf session. The patches 05 updates buffer on AUX pause occasion, which can mitigate the trace data lose issue.
Patch 07 documents the AUX pause usages with Arm CoreSight.
This patch set has been verified on the Hikey960 board and TC platform. The previous one uses ETR and the later uses TRBE as sink.
It is suggested to disable CPUIdle (add `nohlt` option in Linux command line) when verifying this series. ETM and funnel drivers are found issues during CPU suspend and resume which will be addressed separately.
Changes from v2: - Rebased on CoreSight next branch. - Dropped the uAPI 'update_buf_on_pause' and updated document respectively (Suzuki). - Renamed ETM callbacks to .pause_perf() and .resume_perf() (Suzuki). - Minor improvement for error handling in the AUX resume flow.
Changes from v1: - Added validation function pointers in pause and resume APIs (Mike).
Leo Yan (6): coresight: etm4x: Extract the trace unit controlling coresight: Introduce pause and resume APIs for source coresight: etm4x: Hook pause and resume callbacks coresight: perf: Support AUX trace pause and resume coresight: perf: Update buffer on AUX pause Documentation: coresight: Document AUX pause and resume
.../trace/coresight/coresight-perf.rst | 31 ++++ drivers/hwtracing/coresight/coresight-core.c | 22 +++ .../hwtracing/coresight/coresight-etm-perf.c | 84 +++++++++- .../coresight/coresight-etm4x-core.c | 143 +++++++++++++----- drivers/hwtracing/coresight/coresight-etm4x.h | 2 + drivers/hwtracing/coresight/coresight-priv.h | 2 + include/linux/coresight.h | 4 + 7 files changed, 246 insertions(+), 42 deletions(-)