CoreSight

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2547 discussions

[PATCH v6 00/13] coresight: Update timestamp attribute to be an interval instead of bool

by James Clark

Do some cleanups then expand the timestamp format attribute from 1 bit to 4 bits for ETMv4 in Perf mode. The current interval is too high for most use cases, and particularly on the FVP the number of timestamps generated is excessive. This change not only still allows disabling or enabling timestamps, but also allows the interval to be configured. The old bit is kept deprecated and undocumented for now. There are known broken versions of Perf that don't read the format attribute positions from sysfs and instead hard code the timestamp bit. We can leave the old bit in the driver until we need the bit for another feature or enough time has passed that these old Perfs are unlikely to be used. The interval option is added as an event format attribute, rather than a Coresight config because it's something that the driver is already configuring automatically in Perf mode using any unused counter, so it's not possible to modify this with a config. Applies to coresight/next Signed-off-by: James Clark <james.clark(a)linaro.org> --- Changes in v6: - #ifdef out format attributes for ETMv3 instead of using is_visible(). Then the same block can be used to define format_attr_contextid_show() which avoids an awkward WARN_ONCE() and comments in arm32 for a function that's never called. - Link to v5: https://lore.kernel.org/r/20251118-james-cs-syncfreq-v5-0-82efd7b1a751@lina… Changes in v5: - Add parens to interval calculation in docs (Randy) - Swap "minimum interval" and "maximum interval" in docs. (Leo) - Add TRCSYNCPR.PERIOD to docs (Leo) - Use CONFIG_ARM64 to avoid is_kernel_in_hyp_mode() (Leo) - Add a comment for hidden ETMv3 format attributes (Leo) - Hide configid for ETMv3 (Leo) - Link to v4: https://lore.kernel.org/r/20251112-james-cs-syncfreq-v4-0-165ba21401dc@lina… Changes in v4: - Add #defines for true and false resources ETM_RES_SEL_TRUE/FALSE - Reword comment about finding a counter to say if there are no resources there are no counters. - Extend existing timestamp format attribute instead of adding a new one - Refactor all the config definitions and parsing to use GEN_PMU_FORMAT_ATTR()/ATTR_CFG_GET_FLD() so we can see where the unused bits are. - Link to v3: https://lore.kernel.org/r/20251002-james-cs-syncfreq-v3-0-fe5df2bf91d1@lina… Changes in v3: - Move the format attr definitions to coresight-etm-perf.h we can compile on arm32 without #ifdefs - (Leo) - Convert the new #ifdefs to a single one in an is_visible() function so that the code is cleaner - (Leo) - Drop the change to remove the holes in struct etmv4_config as they were grouped by function - (Mike) - Link to v2: https://lore.kernel.org/r/20250814-james-cs-syncfreq-v2-0-c76fcb87696d@lina… Changes in v2: - Only show the attribute for ETMv4 to improve usability and fix the arm32 build error. Wrapping everything in IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) isn't ideal, but the -perf.c file is shared between ETMv3 and ETMv4, and there is already precedent for doing it this way. - Link to v1: https://lore.kernel.org/r/20250811-james-cs-syncfreq-v1-0-b001cd6e3404@lina… --- James Clark (13): coresight: Change syncfreq to be a u8 coresight: Repack struct etmv4_drvdata coresight: Refactor etm4_config_timestamp_event() coresight: Hide unused ETMv3 format attributes coresight: Define format attributes with GEN_PMU_FORMAT_ATTR() coresight: Interpret ETMv3 config with ATTR_CFG_GET_FLD() coresight: Don't reject unrecognized ETMv3 format attributes coresight: Interpret perf config with ATTR_CFG_GET_FLD() coresight: Interpret ETMv4 config with ATTR_CFG_GET_FLD() coresight: Remove misleading definitions coresight: Extend width of timestamp format attribute coresight: Allow setting the timestamp interval coresight: docs: Document etm4x timestamp interval option Documentation/trace/coresight/coresight.rst | 16 +- drivers/hwtracing/coresight/coresight-etm-perf.c | 68 ++++----- drivers/hwtracing/coresight/coresight-etm-perf.h | 39 +++++ drivers/hwtracing/coresight/coresight-etm3x-core.c | 36 ++--- drivers/hwtracing/coresight/coresight-etm4x-core.c | 164 +++++++++++++-------- drivers/hwtracing/coresight/coresight-etm4x.h | 61 +++++--- include/linux/coresight-pmu.h | 24 --- 7 files changed, 244 insertions(+), 164 deletions(-) --- base-commit: 9e9182cab5ebc3ee7544e60ef08ba19fdf216920 change-id: 20250724-james-cs-syncfreq-7c2257a38ed3 Best regards, -- James Clark <james.clark(a)linaro.org>

1 week, 1 day

[PATCH v5 00/19] CoreSight: Refactor power management for CoreSight path

by Leo Yan

This series focuses on CoreSight path power management. The changes can be divided into four parts for review: Patches 01~06: Refactor the CPU idle flow with moving common code into the CoreSight core layer. Patches 07~14: Add link control during CPU idle. Patches 15~16: Support the sink (TRBE) control during CPU idle. Patches 17~19: 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 and FVP RevC. --- 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_impr… Changes in v4: - Changed to store path pointer in coresight_device, this is easier for fetching path pointer based on source device (Mike). - Dropped changes in CTI driver. - Only disabled path for CPU hot-plugged off but not enable path for hot-plugged in. - Removed James' test tags for modified patches. - Link to v3: https://lore.kernel.org/r/20250915-arm_coresight_power_management_fix-v3-0-… Signed-off-by: Leo Yan <leo.yan(a)arm.com> --- Leo Yan (18): coresight: sysfs: Validate CPU online status for per-CPU sources coresight: Set per-CPU source pointer coresight: Register CPU PM notifier in core layer coresight: etm4x: Hook CPU PM callbacks coresight: Add callback to determine if PM is needed 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: Add 'in_idle' argument to path 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 | 1 + drivers/hwtracing/coresight/coresight-core.c | 242 ++++++++++++++++++++- drivers/hwtracing/coresight/coresight-ctcu-core.c | 1 + drivers/hwtracing/coresight/coresight-cti-core.c | 1 + drivers/hwtracing/coresight/coresight-dummy.c | 1 + drivers/hwtracing/coresight/coresight-etb10.c | 1 + drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +- drivers/hwtracing/coresight/coresight-etm3x-core.c | 65 ++---- drivers/hwtracing/coresight/coresight-etm4x-core.c | 153 +++---------- drivers/hwtracing/coresight/coresight-funnel.c | 1 + drivers/hwtracing/coresight/coresight-priv.h | 3 + drivers/hwtracing/coresight/coresight-replicator.c | 1 + drivers/hwtracing/coresight/coresight-stm.c | 1 + drivers/hwtracing/coresight/coresight-syscfg.c | 22 +- drivers/hwtracing/coresight/coresight-syscfg.h | 2 + drivers/hwtracing/coresight/coresight-sysfs.c | 126 ++++------- drivers/hwtracing/coresight/coresight-tmc-core.c | 1 + drivers/hwtracing/coresight/coresight-tnoc.c | 2 + drivers/hwtracing/coresight/coresight-tpda.c | 1 + drivers/hwtracing/coresight/coresight-tpdm.c | 1 + drivers/hwtracing/coresight/coresight-tpiu.c | 1 + drivers/hwtracing/coresight/coresight-trbe.c | 62 +++++- drivers/hwtracing/coresight/ultrasoc-smb.c | 1 + include/linux/coresight.h | 11 + 24 files changed, 429 insertions(+), 274 deletions(-) --- base-commit: 9e9182cab5ebc3ee7544e60ef08ba19fdf216920 change-id: 20251104-arm_coresight_path_power_management_improvement-dab4966f8280 Best regards, -- Leo Yan <leo.yan(a)arm.com>

1 week, 1 day

[PATCH v4 00/15] CoreSight: Refactor power management for CoreSight path

by Leo Yan

This series is extracted from [1], focusing on CoreSight path power management. Compared to the previous version, this series is updated heavily for: 1) Dropped the global per CPU variable for saving path pointers. Instead, the activate path is now stored in the source device's structure. This allows fetching the path pointer naturally based on the source regardless of whether it is a per-CPU source or a system source (such as STM). This improvement addresses Mike's comment that, later we can polish coresight-sysfs.c to remove the tracer_path variables. 2) To simplify the series and make it easier to review, the CTI driver related fixes have been removed from this series and which will be sent out separately. 3) This series disables the path when a CPU is hot-plugged off but does not re-enable it when the CPU is subsequently hot-plugged in. This simplifies the implementation and keep it consistent with the perf session's behavior. It also improves security, as there is no risk of unintended tracing caused by a CPU being hot-plugged after a long period of inactivity. This series is dependent on ETM driver's PM improvement series [2] and has been verified on Juno-r2 and FVP RevC. [1] https://lore.kernel.org/linux-arm-kernel/20250915-arm_coresight_power_manag… [2] https://lore.kernel.org/linux-arm-kernel/20251103-arm_coresight_power_manag… --- Changes in v4: - Changed to store path pointer in coresight_device, this is easier for fetching path pointer based on source device (Mike). - Dropped changes in CTI driver. - Only disabled path for CPU hot-plugged off but not enable path for hot-plugged in. - Removed James' test tags for modified patches. - Link to v3: https://lore.kernel.org/r/20250915-arm_coresight_power_management_fix-v3-0-… Signed-off-by: Leo Yan <leo.yan(a)arm.com> --- Leo Yan (14): coresight: sysfs: Validate CPU online status for per-CPU sources coresight: Set per CPU source pointer coresight: Register CPU PM notifier in core layer coresight: etm4x: Hook CPU PM callbacks coresight: Add callback to determine if PM is needed 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 activated path into source device coresight: Add 'in_idle' argument to enable/disable path functions coresight: Control path during CPU idle coresight: Add PM callbacks for percpu sink 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 | 1 + drivers/hwtracing/coresight/coresight-core.c | 273 ++++++++++++++++++++- drivers/hwtracing/coresight/coresight-ctcu-core.c | 1 + drivers/hwtracing/coresight/coresight-cti-core.c | 1 + drivers/hwtracing/coresight/coresight-dummy.c | 1 + drivers/hwtracing/coresight/coresight-etb10.c | 1 + drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +- drivers/hwtracing/coresight/coresight-etm3x-core.c | 1 + drivers/hwtracing/coresight/coresight-etm4x-core.c | 137 ++--------- drivers/hwtracing/coresight/coresight-funnel.c | 1 + drivers/hwtracing/coresight/coresight-priv.h | 3 + drivers/hwtracing/coresight/coresight-replicator.c | 1 + drivers/hwtracing/coresight/coresight-stm.c | 1 + drivers/hwtracing/coresight/coresight-syscfg.c | 22 +- drivers/hwtracing/coresight/coresight-syscfg.h | 2 + drivers/hwtracing/coresight/coresight-sysfs.c | 12 +- drivers/hwtracing/coresight/coresight-tmc-core.c | 1 + drivers/hwtracing/coresight/coresight-tnoc.c | 2 + drivers/hwtracing/coresight/coresight-tpda.c | 1 + drivers/hwtracing/coresight/coresight-tpdm.c | 1 + drivers/hwtracing/coresight/coresight-tpiu.c | 1 + drivers/hwtracing/coresight/coresight-trbe.c | 85 ++++++- drivers/hwtracing/coresight/ultrasoc-smb.c | 1 + include/linux/coresight.h | 13 + 24 files changed, 425 insertions(+), 140 deletions(-) --- base-commit: f9ac95561513e18c2a2cf8905355dc5f0e030c46 change-id: 20251104-arm_coresight_path_power_management_improvement-dab4966f8280 Best regards, -- Leo Yan <leo.yan(a)arm.com>

1 week, 1 day

[PATCH v4 00/13] coresight: Update timestamp attribute to be an interval instead of bool

by James Clark

Do some cleanups then expand the timestamp format attribute from 1 bit to 4 bits for ETMv4 in Perf mode. The current interval is too high for most use cases, and particularly on the FVP the number of timestamps generated is excessive. This change not only still allows disabling or enabling timestamps, but also allows the interval to be configured. The old bit is kept deprecated and undocumented for now. There are known broken versions of Perf that don't read the format attribute positions from sysfs and instead hard code the timestamp bit. We can leave the old bit in the driver until we need the bit for another feature or enough time has passed that these old Perfs are unlikely to be used. The interval option is added as an event format attribute, rather than a Coresight config because it's something that the driver is already configuring automatically in Perf mode using any unused counter, so it's not possible to modify this with a config. Applies to coresight/next Signed-off-by: James Clark <james.clark(a)linaro.org> --- Changes in v4: - Add #defines for true and false resources ETM_RES_SEL_TRUE/FALSE - Reword comment about finding a counter to say if there are no resources there are no counters. - Extend existing timestamp format attribute instead of adding a new one - Refactor all the config definitions and parsing to use GEN_PMU_FORMAT_ATTR()/ATTR_CFG_GET_FLD() so we can see where the unused bits are. - Link to v3: https://lore.kernel.org/r/20251002-james-cs-syncfreq-v3-0-fe5df2bf91d1@lina… Changes in v3: - Move the format attr definitions to coresight-etm-perf.h we can compile on arm32 without #ifdefs - (Leo) - Convert the new #ifdefs to a single one in an is_visible() function so that the code is cleaner - (Leo) - Drop the change to remove the holes in struct etmv4_config as they were grouped by function - (Mike) - Link to v2: https://lore.kernel.org/r/20250814-james-cs-syncfreq-v2-0-c76fcb87696d@lina… Changes in v2: - Only show the attribute for ETMv4 to improve usability and fix the arm32 build error. Wrapping everything in IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) isn't ideal, but the -perf.c file is shared between ETMv3 and ETMv4, and there is already precedent for doing it this way. - Link to v1: https://lore.kernel.org/r/20250811-james-cs-syncfreq-v1-0-b001cd6e3404@lina… --- James Clark (13): coresight: Change syncfreq to be a u8 coresight: Repack struct etmv4_drvdata coresight: Refactor etm4_config_timestamp_event() coresight: Hide unused ETMv3 format attributes coresight: Define format attributes with GEN_PMU_FORMAT_ATTR() coresight: Interpret ETMv3 config with ATTR_CFG_GET_FLD() coresight: Don't reject unrecognized ETMv3 format attributes coresight: Interpret perf config with ATTR_CFG_GET_FLD() coresight: Interpret ETMv4 config with ATTR_CFG_GET_FLD() coresight: Remove misleading definitions coresight: Extend width of timestamp format attribute coresight: Allow setting the timestamp interval coresight: docs: Document etm4x timestamp interval option Documentation/trace/coresight/coresight.rst | 15 +- drivers/hwtracing/coresight/coresight-etm-perf.c | 59 +++++--- drivers/hwtracing/coresight/coresight-etm-perf.h | 39 +++++ drivers/hwtracing/coresight/coresight-etm3x-core.c | 36 ++--- drivers/hwtracing/coresight/coresight-etm4x-core.c | 164 +++++++++++++-------- drivers/hwtracing/coresight/coresight-etm4x.h | 62 +++++--- include/linux/coresight-pmu.h | 24 --- 7 files changed, 247 insertions(+), 152 deletions(-) --- base-commit: efdccf6a511891db037e08f1351e72eaa101021e change-id: 20250724-james-cs-syncfreq-7c2257a38ed3 Best regards, -- James Clark <james.clark(a)linaro.org>

1 week, 2 days

[PATCH v2 0/1] coresight: fix issue with insufficient claim tags

by Mike Leach

All CoreSight compliant components have an implementation defined number of 0 to 8 claim tag bits in the claim tag registers. These are used to claim the CoreSight resources by system agents. ARM recommends implementions have 4 claim tag registers. The CoreSight drivers implement a 2 claim tag bit protocol to allow self hosted and external debug agents to manage access to the hardware. However, if there are less than 2 claim tags available the protocol incorrectly returns an error on device claim, as no checks are made. If insufficient claim tags are present in a component then the protocol must return success on claim / disclaim to allow components to be used normally. Changes read the CLAIMSET bits to establish the number of available tags, and adjust the claim returns accordingly. Cache the claimtag protocol availablity in the coresight_device to reduce reads for the main claim/disclaim api. changes since v1: 1) Added claim tag availability cache into coresight_device when using the main coresight_claim_device() / coresight_disclaim_device() API. Applies to coresight/next Mike Leach (1): coresight: fix issue where coresight component has no claimtags drivers/hwtracing/coresight/coresight-core.c | 46 ++++++++++++++++++-- drivers/hwtracing/coresight/coresight-priv.h | 10 +++++ include/linux/coresight.h | 15 +++++++ 3 files changed, 68 insertions(+), 3 deletions(-) -- 2.32.0

1 week, 3 days

Re: [PATCH v4 13/13] coresight: docs: Document etm4x timestamp interval option

by James Clark

On 14/11/2025 5:02 am, Randy Dunlap wrote: > > > On 11/12/25 7:22 AM, James Clark wrote: >> Document how the new field is used, maximum value and the interaction >> with SYNC timestamps. >> >> Signed-off-by: James Clark <james.clark(a)linaro.org> >> --- >> Documentation/trace/coresight/coresight.rst | 15 +++++++++++++-- >> 1 file changed, 13 insertions(+), 2 deletions(-) >> >> diff --git a/Documentation/trace/coresight/coresight.rst b/Documentation/trace/coresight/coresight.rst >> index 806699871b80..80b5ed09d69b 100644 >> --- a/Documentation/trace/coresight/coresight.rst >> +++ b/Documentation/trace/coresight/coresight.rst >> @@ -613,8 +613,19 @@ They are also listed in the folder /sys/bus/event_source/devices/cs_etm/format/ >> - Session local version of the system wide setting: :ref:`ETM_MODE_RETURNSTACK >> <coresight-return-stack>` >> * - timestamp >> - - Session local version of the system wide setting: :ref:`ETMv4_MODE_TIMESTAMP >> - <coresight-timestamp>` >> + - Controls generation and interval of timestamps. >> + >> + 0 = off, 1 = maximum interval .. 15 = minimum interval. >> + >> + Values 1 - 14 use a counter that decrements every cycle to generate a >> + timestamp on underflow. The reload value for the counter is 2 raised to >> + the power of timestamp interval - 1. If the value is 1 then the reload >> + value is 1, if the value is 11 then the reload value is 1024 etc. > > value = 11: 2^11-1 = 2047 > > Maybe add some parens? > > Will do. I had them but I removed them because it was in a sentence so it made it look like a side note. I think I'll change from words to symbols: The reload value for the counter is 2 ^ (interval - 1). Thanks James

1 week, 6 days

[PATCH v5 0/3] coresight-tnoc: Add support for Interconnect TNOC

by Yuanfang Zhang

This patch series adds support for the Qualcomm CoreSight Interconnect TNOC (Trace Network On Chip) block, which acts as a CoreSight graph link forwarding trace data from subsystems to the Aggregator TNOC. Unlike the Aggregator TNOC, this block does not support aggregation or ATID assignment. Signed-off-by: Yuanfang Zhang <yuanfang.zhang(a)oss.qualcomm.com> --- Changes in v5: - Add the missing review-by tag for patch 3. - Link to v4: https://lore.kernel.org/r/20250831-itnoc-v4-0-f0fb0ef822a5@oss.qualcomm.com Changes in v4: - Fix unintended blank line removals in trace_noc_enable_hw. - Link to v3: https://lore.kernel.org/r/20250828-itnoc-v3-0-f1b55dea7a27@oss.qualcomm.com Changes in v3: - Add detail for changes in V2. - Remove '#address-cells' and '#size-cells' properties from in-ports field. - Fix comment indentation for packet description. - Link to v2: https://lore.kernel.org/r/20250819-itnoc-v2-0-2d0e6be44e2f@oss.qualcomm.com Changes in v2: - Removed the trailing '|' after the description in qcom,coresight-itnoc.yaml. - Dropped the 'select' section from the YAML file. - Updated node name to use a more generic naming convention. - Removed the 'items' property from the compatible field. - Deleted the description for the reg property. - Dropped clock-names and adjusted the order of clock-names and clocks. - Moved additionalProperties to follow the $ref of out-ports. - Change "atid" type from u32 to int, set it as "-EOPNOTSUPP" for non-AMBA device. - Link to v1: https://lore.kernel.org/r/20250815-itnoc-v1-0-62c8e4f7ad32@oss.qualcomm.com --- Yuanfang Zhang (3): dt-bindings: arm: qcom: Add Coresight Interconnect TNOC coresight-tnoc: add platform driver to support Interconnect TNOC coresight-tnoc: Add runtime PM support for Interconnect TNOC .../bindings/arm/qcom,coresight-itnoc.yaml | 90 ++++++++++++++ drivers/hwtracing/coresight/coresight-tnoc.c | 136 +++++++++++++++++++-- 2 files changed, 215 insertions(+), 11 deletions(-) --- base-commit: 2b52cf338d39d684a1c6af298e8204902c026aca change-id: 20250815-itnoc-460273d1b80c Best regards, -- Yuanfang Zhang <yuanfang.zhang(a)oss.qualcomm.com>

2 weeks

[PATCH v6 00/11] CoreSight: Refactor power management for ETMv3/4

by Leo Yan

This series is extracted from the CoreSight power management fixes and refactoring [1], focusing on ETMv3/4 power management. This series has been verified on Juno-r2 platform. [1] https://lore.kernel.org/linux-arm-kernel/20250915-arm_coresight_power_manag… --- Changes in v6: - Added a 'retain_ss_status' flag to indicate if need to restain single-shot status (Suzuki). - Introduced __etm4_disable_hw() without calling etm4_cs_{unlock|lock}() pairs, which is convenient for the save callback (Suzuki). - Link to v5: https://lore.kernel.org/r/20251103-arm_coresight_power_management_fix-v5-0-… Changes in v5: - Added more info for removing redundant DSB in etm4_{enable|disable}_trace_unit() (Suzuki/Levi). - Dropped moving isb() out from etm4_{enable|disable}_trace_unit() (Suzuki). - Reordered patches to move fixes earlier. - Link to v4: https://lore.kernel.org/r/20251024-arm_coresight_power_management_fix-v4-0-… Changes in v4: - Added patch 10 for retaining sequencer state in ETMv4 driver (Mike). - Added Mike's review tags. - Added James' test tags. - Link to v3: https://lore.kernel.org/r/20250915-arm_coresight_power_management_fix-v3-0-… Changes in v3: - Fixed building failure in ETMv3 driver (kernel test robot). - Refactoring ETMv3 change for checking CPU ID (Levi). - Fixed NULL pointer issue during CPU idle (James). - Fixed lockdep complaint for HARDIRQ-safe and HARDIRA-unsafe (James). - Fixed acquiring mutex in atomic context (James). - Rebased on the latest coresight-next branch. - Link to v2: https://lore.kernel.org/r/20250701-arm_cs_pm_fix_v3-v2-0-23ebb864fcc1@arm.c… Changes in v2: - Refactored ETMv4 suspend and resume for reusing the normal enabling and disabling flows (James). - Used a per-CPU structure to maintain path pointers (James). - Supported helpers in CPU PM flows (James). - Fixed the SMP-safe access to device mode. - Fixed the context synchronization in ETMv4x driver. - Link to v1: https://lore.kernel.org/linux-arm-kernel/20250516160742.1200904-1-leo.yan@a… Signed-off-by: Leo Yan <leo.yan(a)arm.com> --- Leo Yan (11): coresight: Change device mode to atomic type coresight: etm4x: Always set tracer's device mode on target CPU coresight: etm3x: Always set tracer's device mode on target CPU coresight: etm4x: Correct polling IDLE bit coresight: etm4x: Add context synchronization before enabling trace coresight: etm4x: Properly control filter in CPU idle with FEAT_TRF coresight: etm4x: Remove the redundant DSB coresight: etm4x: Remove the state_needs_restore flag coresight: etm4x: Add flag to retain single-shot status coresight: etm4x: Retain sequencer state coresight: etm4x: Reuse normal enable and disable logic in CPU idle drivers/hwtracing/coresight/coresight-etm3x-core.c | 59 ++-- drivers/hwtracing/coresight/coresight-etm4x-core.c | 358 +++++++-------------- drivers/hwtracing/coresight/coresight-etm4x.h | 64 +--- include/linux/coresight.h | 25 +- 4 files changed, 172 insertions(+), 334 deletions(-) --- base-commit: b139702a889692ec30702534ebb1ae2b11ed1cbf change-id: 20250909-arm_coresight_power_management_fix-139873f942e8 Best regards, -- Leo Yan <leo.yan(a)arm.com>

2 weeks, 1 day

Re: [PATCH v2] coresight: etm-perf: Fix reference count leak in etm_setup_aux

by Leo Yan

On 11/12/25 01:24, Ma Ke wrote: > @@ -454,6 +454,11 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, > goto err; > > out: > + if (user_sink) { > + put_device(&user_sink->dev); > + user_sink = NULL; > + } After searched kernel, I prefer to put device in coresight_get_sink_by_id(). Please refer acpi_dev_present() how to do that. I would like Suzuki's confirmation in case I introduce noise. Thanks, Leo

2 weeks, 1 day

[PATCH v7 00/11] CoreSight: Refactor power management for ETMv3/4

by Leo Yan

This series is extracted from the CoreSight power management fixes and refactoring [1], focusing on ETMv3/4 power management. This series has been verified on Juno-r2 platform. [1] https://lore.kernel.org/linux-arm-kernel/20250915-arm_coresight_power_manag… --- Changes in v7: - Updated the commit log in patch 11 (Mike). - Link to v6: https://lore.kernel.org/r/20251111-arm_coresight_power_management_fix-v6-0-… Changes in v6: - Added a 'retain_ss_status' flag to indicate if need to restain single-shot status (Suzuki). - Introduced __etm4_disable_hw() without calling etm4_cs_{unlock|lock}() pairs, which is convenient for the save callback (Suzuki). - Link to v5: https://lore.kernel.org/r/20251103-arm_coresight_power_management_fix-v5-0-… Changes in v5: - Added more info for removing redundant DSB in etm4_{enable|disable}_trace_unit() (Suzuki/Levi). - Dropped moving isb() out from etm4_{enable|disable}_trace_unit() (Suzuki). - Reordered patches to move fixes earlier. - Link to v4: https://lore.kernel.org/r/20251024-arm_coresight_power_management_fix-v4-0-… Changes in v4: - Added patch 10 for retaining sequencer state in ETMv4 driver (Mike). - Added Mike's review tags. - Added James' test tags. - Link to v3: https://lore.kernel.org/r/20250915-arm_coresight_power_management_fix-v3-0-… Changes in v3: - Fixed building failure in ETMv3 driver (kernel test robot). - Refactoring ETMv3 change for checking CPU ID (Levi). - Fixed NULL pointer issue during CPU idle (James). - Fixed lockdep complaint for HARDIRQ-safe and HARDIRA-unsafe (James). - Fixed acquiring mutex in atomic context (James). - Rebased on the latest coresight-next branch. - Link to v2: https://lore.kernel.org/r/20250701-arm_cs_pm_fix_v3-v2-0-23ebb864fcc1@arm.c… Changes in v2: - Refactored ETMv4 suspend and resume for reusing the normal enabling and disabling flows (James). - Used a per-CPU structure to maintain path pointers (James). - Supported helpers in CPU PM flows (James). - Fixed the SMP-safe access to device mode. - Fixed the context synchronization in ETMv4x driver. - Link to v1: https://lore.kernel.org/linux-arm-kernel/20250516160742.1200904-1-leo.yan@a… Signed-off-by: Leo Yan <leo.yan(a)arm.com> --- Leo Yan (11): coresight: Change device mode to atomic type coresight: etm4x: Always set tracer's device mode on target CPU coresight: etm3x: Always set tracer's device mode on target CPU coresight: etm4x: Correct polling IDLE bit coresight: etm4x: Add context synchronization before enabling trace coresight: etm4x: Properly control filter in CPU idle with FEAT_TRF coresight: etm4x: Remove the redundant DSB coresight: etm4x: Remove the state_needs_restore flag coresight: etm4x: Add flag to retain single-shot status coresight: etm4x: Retain sequencer state coresight: etm4x: Reuse normal enable and disable logic in CPU idle drivers/hwtracing/coresight/coresight-etm3x-core.c | 59 ++-- drivers/hwtracing/coresight/coresight-etm4x-core.c | 358 +++++++-------------- drivers/hwtracing/coresight/coresight-etm4x.h | 64 +--- include/linux/coresight.h | 25 +- 4 files changed, 172 insertions(+), 334 deletions(-) --- base-commit: b139702a889692ec30702534ebb1ae2b11ed1cbf change-id: 20250909-arm_coresight_power_management_fix-139873f942e8 Best regards, -- Leo Yan <leo.yan(a)arm.com>

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