[PATCH v5 00/12] fix several inconsistencies with sysfs configuration in etmX

[Yeoreum Yun]

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().

This patch based on v7.0

Patch History
=============
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@xxxxxxx/

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@xxxxxxx/

from v2 to v3:
  - fix build error for etm3x.
  - fix checkpatch warning.
  - https://lore.kernel.org/all/20260410074310.2693385-1-yeoreum.yun@xxxxxxx/

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@xxxxxxx/

Yeoreum Yun (12):
  coresight: etm4x: fix wrong check of etm4x_sspcicrn_present()
  coresight: etm4x: fix underflow for nrseqstate
  coresight: etm4x: introduce struct etm4_caps
  coresight: etm4x: exclude ss_status from drvdata->config
  coresight: etm4x: remove redundant fields in etmv4_save_state
  coresight: etm4x: fix leaked trace id
  coresight: etm4x: fix inconsistencies with sysfs configuration
  coresight: etm4x: remove redundant call etm4_enable_hw() with hotplug
  coresight: etm3x: change drvdata->spinlock type to raw_spin_lock_t
  coresight: etm3x: introduce struct etm_caps
  coresight: etm3x: fix inconsistencies with sysfs configuration
  coresight: etm3x: remove redundant call etm_enable_hw() with hotplug

 drivers/hwtracing/coresight/coresight-etm.h   |  46 ++-
 .../coresight/coresight-etm3x-core.c          | 100 ++---
 .../coresight/coresight-etm3x-sysfs.c         | 159 ++++----
 .../hwtracing/coresight/coresight-etm4x-cfg.c |   3 +-
 .../coresight/coresight-etm4x-core.c          | 374 ++++++++++--------
 .../coresight/coresight-etm4x-sysfs.c         | 199 ++++++----
 drivers/hwtracing/coresight/coresight-etm4x.h | 190 ++++-----
 7 files changed, 588 insertions(+), 483 deletions(-)


base-commit: 028ef9c96e96197026887c0f092424679298aae8
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LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}