The current ETMx configuration via sysfs can lead to the following inconsistencies:
- If a configuration is modified via sysfs while a perf session is active, the running configuration may differ between before a sched-out and after a subsequent sched-in.
- If a perf session and sysfs session tries to enable concurrently, configuration from configfs could be corrupted (etm4).
- There is chance to corrupt drvdata->config if perf session tries to enabled among handling cscfg_csdev_disable_active_config() in etm4_disable_sysfs() (etm4).
To resolve these inconsistencies, the configuration should be separated into:
- active_config, which is applied configuration for the current session - config, which stores the settings configured via sysfs.
and apply configuration from configfs after taking a mode.
Also, This patch set includes some small fixes: - missing trace id release in etm4x. - underflow issue for nrseqstate. - wrong check in etm4x_sspcicrn_present(). - missing call of cscfg_csdev_disable_active_config()
This patch based on coresight tree's next
Patch History ============= from v8 to v9: - add feat_csdev_lock guard interface. - set feat_csdev->drv_spinlock as NULL for etmv4_drvdata. - https://lore.kernel.org/all/20260629090007.1718746-1-yeoreum.yun@arm.com/
from v7 to v8: - accept @Leo Yan' suggestion to handle error. - small minor fixes following @Suzuki' suggestion. - https://lore.kernel.org/all/20260519154812.254884-1-yeoreum.yun@arm.com/
from v6 to v7: - rebase on coresight/next - add ETM_MAX_SEQ_TRANSITIONS define - remove redundant patch relavent cpu-hotplug as coresight-pm patch merged. - https://lore.kernel.org/all/20260422132203.977549-1-yeoreum.yun@arm.com/
from v5 to v6: - fix missing of calling cscfg_csdev_disable_active_config() - add rb & fixes tags. - add ss_status field in etm4x_drvdata to expose STATUS and PENDING bits. - https://lore.kernel.org/all/20260415165528.3369607-1-yeoreum.yun@arm.com/
from v4 to v5: - add rb-tag. - fix underflow issue for nrseqstate. - fix wrong check in etm4_sspcicrn_present(). - remove redundant fields on etmv4_save_state. - rename caps->ss_status to ss_cmp. - fix wrong location of etm4_release_trace_id. - https://lore.kernel.org/all/20260413142003.3549310-1-yeoreum.yun@arm.com/
from v3 to v4: - change etm_drvdata->spinlock type to raw_spin_lock_t - remove redundant call etmX_enable_hw() with starting_cpu() callsback. - fix missing trace id release. - add missing docs. - https://lore.kernel.org/all/20260412175506.412301-1-yeoreum.yun@arm.com/
from v2 to v3: - fix build error for etm3x. - fix checkpatch warning. - https://lore.kernel.org/all/20260410074310.2693385-1-yeoreum.yun@arm.com/
from v1 to v2 - rebased to v7.0-rc7. - introduce etmX_caps structure to save etmX's capabilities. - remove ss_status from etmv4_config. - modify active_config after taking a mode (perf/sysfs). - https://lore.kernel.org/all/20260317181705.2456271-1-yeoreum.yun@arm.com/
Yeoreum Yun (13): coresight: etm4x: fix wrong check of etm4x_sspcicrn_present() coresight: etm4x: fix underflow for usage of (nrseqstate - 1) coresight: etm4x: fix leaked trace id coresight: etm4x: fix inconsistencies with sysfs configuration coresight: etm4x: missing cscfg_csdev_disable_active_config() in perf enable coresight: etm3x: fix inconsistencies with sysfs configuration coresight: etm3x: change drvdata->spinlock type to raw_spin_lock_t coresight: etm3x: remove redundant cpu online check on etm_enable_sysfs() coresight: etm4x: introduce struct etm4_caps coresight: etm4x: exclude ss_status from drvdata->config coresight: etm4x: remove s_ex_level from config coresight: etm4x: remove redundant fields in etmv4_save_state coresight: etm3x: introduce struct etm_caps
.../hwtracing/coresight/coresight-config.c | 18 +- .../hwtracing/coresight/coresight-config.h | 26 + drivers/hwtracing/coresight/coresight-etm.h | 48 +- .../coresight/coresight-etm3x-core.c | 96 ++-- .../coresight/coresight-etm3x-sysfs.c | 159 +++--- .../hwtracing/coresight/coresight-etm4x-cfg.c | 16 +- .../coresight/coresight-etm4x-core.c | 454 ++++++++++-------- .../coresight/coresight-etm4x-sysfs.c | 204 ++++---- drivers/hwtracing/coresight/coresight-etm4x.h | 204 ++++---- 9 files changed, 682 insertions(+), 543 deletions(-)
base-commit: 98495b5a4d77dd22e106f462b76e1093a55b29a7