Messages in this thread | | | From | Mike Leach <> | Date | Tue, 17 Jan 2023 13:02:29 +0000 | Subject | Re: [PATCH v7 01/15] coresight: trace-id: Add API to dynamically assign Trace ID values |
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On Mon, 16 Jan 2023 at 14:16, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: > > 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 > > ... > > > +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. > OK, thanks.
The only thing I get out of checkpatch.pl for this patch (and indeed the entire set) is:
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
Mike
> > diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h > >
-- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
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