Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Wed, 17 Mar 2021 13:31:36 -0600 | From | Mathieu Poirier <> | Subject | Re: [PATCH v4 17/19] coresight: core: Add support for dedicated percpu sinks |
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On Thu, Feb 25, 2021 at 07:35:41PM +0000, Suzuki K Poulose wrote: > From: Anshuman Khandual <anshuman.khandual@arm.com> > > Add support for dedicated sinks that are bound to individual CPUs. (e.g, > TRBE). To allow quicker access to the sink for a given CPU bound source, > keep a percpu array of the sink devices. Also, add support for building > a path to the CPU local sink from the ETM. > > This adds a new percpu sink type CORESIGHT_DEV_SUBTYPE_SINK_PERCPU_SYSMEM. > This new sink type is exclusively available and can only work with percpu > source type device CORESIGHT_DEV_SUBTYPE_SOURCE_PROC. > > This defines a percpu structure that accommodates a single coresight_device > which can be used to store an initialized instance from a sink driver. As > these sinks are exclusively linked and dependent on corresponding percpu > sources devices, they should also be the default sink device during a perf > session. > > Outwards device connections are scanned while establishing paths between a > source and a sink device. But such connections are not present for certain > percpu source and sink devices which are exclusively linked and dependent. > Build the path directly and skip connection scanning for such devices. > > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Mike Leach <mike.leach@linaro.org> > Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> > Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > [Moved the set/get percpu sink APIs from TRBE patch to here] > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > Changes: > - Export methods to set/get percpu sinks for fixing module > build for TRBE > - Addressed coding style comments (Suzuki) > - Check status of _coresight_build_path() (Mathieu) > --- > drivers/hwtracing/coresight/coresight-core.c | 29 ++++++++++++++++++-- > drivers/hwtracing/coresight/coresight-priv.h | 3 ++ > include/linux/coresight.h | 12 ++++++++ > 3 files changed, 42 insertions(+), 2 deletions(-)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c > index 0062c8935653..55c645616bf6 100644 > --- a/drivers/hwtracing/coresight/coresight-core.c > +++ b/drivers/hwtracing/coresight/coresight-core.c > @@ -23,6 +23,7 @@ > #include "coresight-priv.h" > > static DEFINE_MUTEX(coresight_mutex); > +DEFINE_PER_CPU(struct coresight_device *, csdev_sink); > > /** > * struct coresight_node - elements of a path, from source to sink > @@ -70,6 +71,18 @@ void coresight_remove_cti_ops(void) > } > EXPORT_SYMBOL_GPL(coresight_remove_cti_ops); > > +void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev) > +{ > + per_cpu(csdev_sink, cpu) = csdev; > +} > +EXPORT_SYMBOL_GPL(coresight_set_percpu_sink); > + > +struct coresight_device *coresight_get_percpu_sink(int cpu) > +{ > + return per_cpu(csdev_sink, cpu); > +} > +EXPORT_SYMBOL_GPL(coresight_get_percpu_sink); > + > static int coresight_id_match(struct device *dev, void *data) > { > int trace_id, i_trace_id; > @@ -784,6 +797,14 @@ static int _coresight_build_path(struct coresight_device *csdev, > if (csdev == sink) > goto out; > > + if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) && > + sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) { > + if (_coresight_build_path(sink, sink, path) == 0) { > + found = true; > + goto out; > + } > + } > + > /* Not a sink - recursively explore each port found on this element */ > for (i = 0; i < csdev->pdata->nr_outport; i++) { > struct coresight_device *child_dev; > @@ -999,8 +1020,12 @@ coresight_find_default_sink(struct coresight_device *csdev) > int depth = 0; > > /* look for a default sink if we have not found for this device */ > - if (!csdev->def_sink) > - csdev->def_sink = coresight_find_sink(csdev, &depth); > + if (!csdev->def_sink) { > + if (coresight_is_percpu_source(csdev)) > + csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev)); > + if (!csdev->def_sink) > + csdev->def_sink = coresight_find_sink(csdev, &depth); > + } > return csdev->def_sink; > } > > diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h > index f5f654ea2994..ff1dd2092ac5 100644 > --- a/drivers/hwtracing/coresight/coresight-priv.h > +++ b/drivers/hwtracing/coresight/coresight-priv.h > @@ -232,4 +232,7 @@ coresight_find_csdev_by_fwnode(struct fwnode_handle *r_fwnode); > void coresight_set_assoc_ectdev_mutex(struct coresight_device *csdev, > struct coresight_device *ect_csdev); > > +void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev); > +struct coresight_device *coresight_get_percpu_sink(int cpu); > + > #endif > diff --git a/include/linux/coresight.h b/include/linux/coresight.h > index 976ec2697610..8a3a3c199087 100644 > --- a/include/linux/coresight.h > +++ b/include/linux/coresight.h > @@ -50,6 +50,7 @@ enum coresight_dev_subtype_sink { > CORESIGHT_DEV_SUBTYPE_SINK_PORT, > CORESIGHT_DEV_SUBTYPE_SINK_BUFFER, > CORESIGHT_DEV_SUBTYPE_SINK_SYSMEM, > + CORESIGHT_DEV_SUBTYPE_SINK_PERCPU_SYSMEM, > }; > > enum coresight_dev_subtype_link { > @@ -428,6 +429,17 @@ static inline void csdev_access_write64(struct csdev_access *csa, u64 val, u32 o > csa->write(val, offset, false, true); > } > > +static inline bool coresight_is_percpu_source(struct coresight_device *csdev) > +{ > + return csdev && (csdev->type == CORESIGHT_DEV_TYPE_SOURCE) && > + (csdev->subtype.source_subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_PROC); > +} > + > +static inline bool coresight_is_percpu_sink(struct coresight_device *csdev) > +{ > + return csdev && (csdev->type == CORESIGHT_DEV_TYPE_SINK) && > + (csdev->subtype.sink_subtype == CORESIGHT_DEV_SUBTYPE_SINK_PERCPU_SYSMEM); > +} > #else /* !CONFIG_64BIT */ > > static inline u64 csdev_access_relaxed_read64(struct csdev_access *csa, > -- > 2.24.1 >
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