This series adds the support for using the tmc-etr in perf mode for storing the trace to system RAM. The ETR uses a separate buffer (double buffering) for storing the trace. This is copied back to the ring buffer when the event is stopped. We try to match the ETR buffer to the larger of perf ring buffer or the size configured for the ETR via sysfs. This allows tuning the buffer size to prevent overflows and loosing trace data, as we don't have overflow interrupt support (yet).
Applies on coresight/next
Changes since v2: - Split hotplug lock cleanup from per-cpu path management - Add support for tracing on hotplugged CPUs (based on patch by Mathieu) - Fix handling of perf mode in etb10 driver - Fix CS_UNLOCK() typo in ETR perf driver - Rename call backs from tmc_etr_<op>_perf_buffer => tmc_<op>_etr_buffer to be consistent with ETF driver - Modify the commit description for removing set_buffer call back.
Changes since v1 : - Fix path for each CPU where the event might be recorded. - Handle errors in enabling source - Remove set_buffer callback to avoid complicating the error handling. - Fix a bug in handling sysfs mode specific buffers
Changes since [0] : - Drop buffer rotation logic for etr-buf - Do not use perf ring buffer. (Add support later) - Fix handling of sink, preventing mixed modes of operation.
[0] - TMC ETR perf support - http://lists.infradead.org/pipermail/linux-arm-kernel/2018-May/574875.html
Suzuki K Poulose (13): coresight: Fix handling of sinks coresight: etb10: Fix handling of perf mode coresight: perf: Fix per cpu path management coresight: perf: Avoid unncessary CPU hotplug read lock coresight: perf: Allow tracing on hotplugged CPUs coresight: perf: Disable trace path upon source error coresight: tmc-etr: Handle driver mode specific ETR buffers coresight: tmc-etr: Relax collection of trace from sysfs mode coresight: Convert driver messages to dev_dbg coresight: perf: Remove reset_buffer call back for sinks coresight: perf: Add helper to retrieve sink configuration coresight: perf: Remove set_buffer call back coresight: etm-perf: Add support for ETR backend
.../coresight/coresight-dynamic-replicator.c | 4 +- drivers/hwtracing/coresight/coresight-etb10.c | 100 +++---- drivers/hwtracing/coresight/coresight-etm-perf.c | 134 +++++---- drivers/hwtracing/coresight/coresight-etm-perf.h | 26 ++ drivers/hwtracing/coresight/coresight-etm3x.c | 4 +- drivers/hwtracing/coresight/coresight-etm4x.c | 4 +- drivers/hwtracing/coresight/coresight-funnel.c | 4 +- drivers/hwtracing/coresight/coresight-priv.h | 2 +- drivers/hwtracing/coresight/coresight-replicator.c | 4 +- drivers/hwtracing/coresight/coresight-stm.c | 4 +- drivers/hwtracing/coresight/coresight-tmc-etf.c | 94 +++--- drivers/hwtracing/coresight/coresight-tmc-etr.c | 327 ++++++++++++++++++--- drivers/hwtracing/coresight/coresight-tmc.c | 4 +- drivers/hwtracing/coresight/coresight-tmc.h | 4 + drivers/hwtracing/coresight/coresight-tpiu.c | 6 +- drivers/hwtracing/coresight/coresight.c | 31 +- include/linux/coresight.h | 12 +- 17 files changed, 517 insertions(+), 247 deletions(-)