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Message-Id: <20230308173904.3449231-1-james.clark@arm.com>
Date: Wed, 8 Mar 2023 17:38:54 +0000
From: James Clark <james.clark@....com>
To: coresight@...ts.linaro.org
Cc: James Clark <james.clark@....com>,
Mathieu Poirier <mathieu.poirier@...aro.org>,
Suzuki K Poulose <suzuki.poulose@....com>,
Mike Leach <mike.leach@...aro.org>,
Leo Yan <leo.yan@...aro.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 0/8] coresight: Fix CTI module refcount leak by making it a helper device
Currently there is a refcount leak in CTI when using system wide mode
or tracing multithreaded applications. See the last commit for a
reproducer. This prevents the module from being unloaded.
Historically there have been a few issues and fixes attempted around
here which have resulted in some extra logic and a member to keep
track of CTI being enabled 'struct coresight_device->ect_enabled'.
The fix in commit 665c157e0204 ("coresight: cti: Fix hang in
cti_disable_hw()") was also related to CTI having its own
enable/disable path which came later than other devices.
If we make CTI a helper device and enable helper devices adjacent to
the path we get very similar enable/disable behavior to now, but with
more reuse of the existing reference counting logic in the coresight
core code. This also affects CATU which can have a little bit of
its hard coded enable/disable code removed.
Enabling CATU on the generic path does require that input connections
are tracked so that it can get its associated ETR buffer.
Applies to coresight/next (669c4614236a7) but also requires the
realloc_array patch here [1].
Also available in full here [2].
[1]: https://lore.kernel.org/linux-arm-kernel/20230306152723.3090195-1-james.clark@arm.com/
[2]: https://gitlab.arm.com/linux-arm/linux-jc/-/tree/james-cs-cti-module-refcount-fix-v1
James Clark (8):
coresight: Use enum type for cs_mode wherever possible
coresight: Change name of pdata->conns
coresight: Rename nr_outports to nr_outconns
coresight: Dynamically add connections
coresight: Store in-connections as well as out-connections
coresight: Refactor out buffer allocation function for ETR
coresight: Enable and disable helper devices adjacent to the path
coresight: Fix CTI module refcount leak by making it a helper device
drivers/hwtracing/coresight/coresight-catu.c | 34 ++-
drivers/hwtracing/coresight/coresight-core.c | 258 +++++++++++-------
.../hwtracing/coresight/coresight-cti-core.c | 56 ++--
.../hwtracing/coresight/coresight-cti-sysfs.c | 4 +-
drivers/hwtracing/coresight/coresight-cti.h | 4 +-
drivers/hwtracing/coresight/coresight-etb10.c | 3 +-
.../coresight/coresight-etm3x-core.c | 6 +-
.../coresight/coresight-etm4x-core.c | 6 +-
.../hwtracing/coresight/coresight-platform.c | 168 +++++++++---
drivers/hwtracing/coresight/coresight-priv.h | 9 +-
drivers/hwtracing/coresight/coresight-stm.c | 6 +-
drivers/hwtracing/coresight/coresight-sysfs.c | 1 -
.../hwtracing/coresight/coresight-tmc-etf.c | 2 +-
.../hwtracing/coresight/coresight-tmc-etr.c | 88 +++---
drivers/hwtracing/coresight/coresight-tmc.h | 2 +
drivers/hwtracing/coresight/coresight-tpdm.c | 4 +-
drivers/hwtracing/coresight/coresight-tpiu.c | 3 +-
drivers/hwtracing/coresight/coresight-trbe.c | 3 +-
drivers/hwtracing/coresight/ultrasoc-smb.c | 3 +-
drivers/hwtracing/coresight/ultrasoc-smb.h | 2 +-
include/linux/coresight.h | 92 ++++---
21 files changed, 483 insertions(+), 271 deletions(-)
--
2.34.1
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