[PATCH v4 0/7] coresight: Clear self hosted claim tag on probe

[James Clark]

I've gotten stuck a few times with unusable Coresight after a warm boot
due to lingering claim tags, especially when testing the Coresight
panic patchsets.

This change does some tidy ups, adds some debug messages and clears the
self hosted claim tag on probe. The last two commits are unrelated
tidyups but they touch some of the same functions so to avoid extra
conflicts I'm including them here.

This gets as far as fixing the claim tag issue, but there is some other
state not being cleared on probe that results in the following error.
This can be fixed up as a later change:

  coresight tmc_etf0: timeout while waiting for TMC to be Ready
  coresight tmc_etf0: Failed to enable : TMC is not ready

Changes in v4:
- Add _unlocked() suffix for consistency
- s/cs_access/csdev_access/

- Link to v3: https://lore.kernel.org/r/20250320-james-coresight-claim-tags-v3-0-d3145c153820@linaro.org

Changes in v3:
- Collapse rename and locked/unlocked addition commits of
  coresight_clear_self_claim_tag() so we don't change the name twice.
- Make coresight_clear_self_claim_tag() a bit more generic by only
  doing UNLOCK for MMIO devices (although there is no use of this right
  now)
- Link to v2: https://lore.kernel.org/r/20250318-james-coresight-claim-tags-v2-0-e9c8a9cde84e@linaro.org

Changes in v2:
 * Revert most of the interface changes, just call
   coresight_clear_self_claim_tag() directly. This is possible because
   we're not doing the read first, so it has fewer knock on effects.
 * Split out the change to add struct cs_access to etm3x
 * Add another warning for racing with external debugger

--
2.34.1

---
James Clark (7):
      coresight: Convert tag clear function to take a struct csdev_access
      coresight: Only check bottom two claim bits
      coresight: Add claim tag warnings and debug messages
      coresight: etm3x: Convert raw base pointer to struct coresight access
      coresight: Clear self hosted claim tag on probe
      coresight: Remove inlines from static function definitions
      coresight: Remove extern from function declarations

 drivers/hwtracing/coresight/coresight-catu.c       | 12 +--
 drivers/hwtracing/coresight/coresight-core.c       | 87 ++++++++++++++--------
 drivers/hwtracing/coresight/coresight-cti-core.c   |  2 +
 drivers/hwtracing/coresight/coresight-etb10.c      |  4 +-
 drivers/hwtracing/coresight/coresight-etm.h        |  6 +-
 drivers/hwtracing/coresight/coresight-etm3x-core.c | 28 +++----
 .../hwtracing/coresight/coresight-etm3x-sysfs.c    |  8 +-
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 ++-
 .../hwtracing/coresight/coresight-etm4x-sysfs.c    |  4 +-
 drivers/hwtracing/coresight/coresight-funnel.c     |  1 +
 drivers/hwtracing/coresight/coresight-platform.c   | 26 +++----
 drivers/hwtracing/coresight/coresight-priv.h       | 20 ++---
 drivers/hwtracing/coresight/coresight-replicator.c |  3 +-
 drivers/hwtracing/coresight/coresight-stm.c        |  6 +-
 .../coresight/coresight-syscfg-configfs.c          |  2 +-
 drivers/hwtracing/coresight/coresight-tmc-core.c   |  9 ++-
 drivers/hwtracing/coresight/coresight-tmc-etr.c    | 16 ++--
 drivers/hwtracing/coresight/coresight-trbe.c       | 18 ++---
 include/linux/coresight.h                          | 40 +++++-----
 19 files changed, 168 insertions(+), 134 deletions(-)
---
base-commit: 5442d22da7dbff3ba8c6720fc6f23ea4934d402d
change-id: 20250317-james-coresight-claim-tags-ae1461f1f5e0

Best regards,
-- 
James Clark <james.clark at linaro.org>