Messages in this thread | | | Date | Mon, 16 Jan 2023 14:16:39 +0000 | Subject | Re: [PATCH v7 01/15] coresight: trace-id: Add API to dynamically assign Trace ID values | From | Suzuki K Poulose <> |
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Hi Mike
On 16/01/2023 12:49, Mike Leach wrote: > The existing mechanism to assign Trace ID values to sources is limited > and does not scale for larger multicore / multi trace source systems. > > The API introduces functions that reserve IDs based on availabilty > represented by a coresight_trace_id_map structure. This records the > used and free IDs in a bitmap. > > CPU bound sources such as ETMs use the coresight_trace_id_get_cpu_id > coresight_trace_id_put_cpu_id pair of functions. The API will record > the ID associated with the CPU. This ensures that the same ID will be > re-used while perf events are active on the CPU. The put_cpu_id function > will pend release of the ID until all perf cs_etm sessions are complete. > > For backward compatibility the functions will attempt to use the same > CPU IDs as the legacy system would have used if these are still available. > > Non-cpu sources, such as the STM can use coresight_trace_id_get_system_id / > coresight_trace_id_put_system_id. > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > --- > drivers/hwtracing/coresight/Makefile | 2 +- > .../hwtracing/coresight/coresight-trace-id.c | 265 ++++++++++++++++++ > .../hwtracing/coresight/coresight-trace-id.h | 156 +++++++++++ > include/linux/coresight-pmu.h | 10 + > 4 files changed, 432 insertions(+), 1 deletion(-) > create mode 100644 drivers/hwtracing/coresight/coresight-trace-id.c > create mode 100644 drivers/hwtracing/coresight/coresight-trace-id.h > > diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile > index b6c4a48140ec..329a0c704b87 100644 > --- a/drivers/hwtracing/coresight/Makefile > +++ b/drivers/hwtracing/coresight/Makefile > @@ -6,7 +6,7 @@ obj-$(CONFIG_CORESIGHT) += coresight.o > coresight-y := coresight-core.o coresight-etm-perf.o coresight-platform.o \ > coresight-sysfs.o coresight-syscfg.o coresight-config.o \ > coresight-cfg-preload.o coresight-cfg-afdo.o \ > - coresight-syscfg-configfs.o > + coresight-syscfg-configfs.o coresight-trace-id.o > obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o > coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \ > coresight-tmc-etr.o > diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c > new file mode 100644 > index 000000000000..9b85c376cb12 > --- /dev/null > +++ b/drivers/hwtracing/coresight/coresight-trace-id.c > @@ -0,0 +1,265 @@ > +// SPDX-License-Identifier: GPL-2.0
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> +int coresight_trace_id_read_cpu_id(int cpu) > +{ > + return _coresight_trace_id_read_cpu_id(cpu); > +} > +EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id); > + > +int coresight_trace_id_get_system_id(void) > +{ > + return coresight_trace_id_map_get_system_id(&id_map_default); > +} > +EXPORT_SYMBOL_GPL(coresight_trace_id_get_system_id); > + > +void coresight_trace_id_put_system_id(int id) > +{ > + coresight_trace_id_map_put_system_id(&id_map_default, id); > +} > +EXPORT_SYMBOL_GPL(coresight_trace_id_put_system_id); > + > +void coresight_trace_id_perf_start(void) > +{ > + atomic_inc(&perf_cs_etm_session_active); > +} > +EXPORT_SYMBOL_GPL(coresight_trace_id_perf_start); > + > +void coresight_trace_id_perf_stop(void) > +{ > + if (!atomic_dec_return(&perf_cs_etm_session_active)) > + coresight_trace_id_release_all_pending(); > +} > +EXPORT_SYMBOL_GPL(coresight_trace_id_perf_stop); > +
This blank new line at the end of the file generates a checkpatch warning for me. I have fixed it locally and applied it.
> diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h
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