This series focuses on CoreSight path power management. The changes can be divided into four parts for review:
Patches 01~07: Refactor the CPU idle flow with moving common code into the CoreSight core layer. Patches 08~15: Refactor path enabling and disabling with range, add path control during CPU idle. Patches 16~17: Support the sink (TRBE) control during CPU idle. Patches 18~20: Move the CPU hotplug flow into the coresight core layer and simplify the code.
This series is rebased on the coresight-next branch and has been verified on Juno-r2 (ETM + ETR) and FVP RevC (ETE + TRBE).
--- Changes in v7: - Added a flag in coresight_desc to indicate CPU bound device (Suzuki). - Used coresight_mutex to protect per-CPU source pointer (Suzuki). - Added a spinlock for exclusive access per-CPU source pointer (Suzuki). - Dropped .pm_is_needed() callback (Suzuki). - Supported range in path enabling / disabling (Suzuki). - Gathered test and review tags (Levi / James). - Link to v6: https://lore.kernel.org/r/20260305-arm_coresight_path_power_management_impro...
Changes in v6: - Rebase on the latest coresight-next branch. - Always save and restore TRBE context during idle (Will). - Use get_cpu() / put_cpu() when set the per CPU source pointer. - Link to v5: https://lore.kernel.org/r/20251119-arm_coresight_path_power_management_impro...
Changes in v5: - Set the per-CPU source pointer on target CPU (Suzuki). - Reused existed enable/disable buffer functions in TRBE callbacks (James). - Refactored refcount for source devices in SysFS mode. - Released path in cpu-hotplug off flow to avoid memory leak. - Updated ETMv3 driver when move common code into core layer. - Rebased on the latest coresight-next branch. - Link to v4: https://lore.kernel.org/r/20251104-arm_coresight_path_power_management_impro...
Signed-off-by: Leo Yan leo.yan@arm.com
--- Leo Yan (19): coresight: Populate CPU ID into coresight_device coresight: Remove .cpu_id() callback from source ops coresight: sysfs: Validate CPU online status for per-CPU sources coresight: Move per-CPU source pointer to core layer coresight: Register CPU PM notifier in core layer coresight: etm4x: Hook CPU PM callbacks coresight: etm4x: Remove redundant condition checks in save and restore coresight: syscfg: Use spinlock to protect active variables coresight: Introduce coresight_enable_source() helper coresight: Save active path for system tracers coresight: etm4x: Set active path on target CPU coresight: etm3x: Set active path on target CPU coresight: sysfs: Use source's path pointer for path control coresight: Control path with range coresight: Control path during CPU idle coresight: Add PM callbacks for sink device coresight: sysfs: Increment refcount only for system tracers coresight: Take hotplug lock in enable_source_store() for Sysfs mode coresight: Move CPU hotplug callbacks to core layer
Yabin Cui (1): coresight: trbe: Save and restore state across CPU low power state
drivers/hwtracing/coresight/coresight-catu.c | 2 +- drivers/hwtracing/coresight/coresight-core.c | 377 +++++++++++++++++++-- drivers/hwtracing/coresight/coresight-cti-core.c | 9 +- drivers/hwtracing/coresight/coresight-etm-perf.c | 25 +- drivers/hwtracing/coresight/coresight-etm3x-core.c | 73 +--- drivers/hwtracing/coresight/coresight-etm4x-core.c | 154 ++------- drivers/hwtracing/coresight/coresight-priv.h | 4 + drivers/hwtracing/coresight/coresight-syscfg.c | 21 +- drivers/hwtracing/coresight/coresight-syscfg.h | 2 + drivers/hwtracing/coresight/coresight-sysfs.c | 126 +++---- drivers/hwtracing/coresight/coresight-trbe.c | 61 +++- include/linux/coresight.h | 15 +- 12 files changed, 546 insertions(+), 323 deletions(-) --- base-commit: a90863095f84f6d17c49716e4e2212d28a6b25b5 change-id: 20251104-arm_coresight_path_power_management_improvement-dab4966f8280
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