Messages in this thread | | | Subject | Re: [PATCH V3 08/14] coresight: core: Add support for dedicated percpu sinks | From | Suzuki K Poulose <> | Date | Thu, 28 Jan 2021 09:16:34 +0000 |
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On 1/27/21 8:55 AM, Anshuman Khandual wrote: > 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_PERCPU_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> > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > --- > Changes in V3: > > - Updated coresight_find_default_sink() > > drivers/hwtracing/coresight/coresight-core.c | 16 ++++++++++++++-- > include/linux/coresight.h | 12 ++++++++++++ > 2 files changed, 26 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c > index 0062c89..4795e28 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 > @@ -784,6 +785,13 @@ 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))) { > + _coresight_build_path(sink, sink, path); > + 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 +1007,12 @@ 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/include/linux/coresight.h b/include/linux/coresight.h > index 976ec26..bc3a5ca 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;
Please add () around the last line. Same below.
> +} > + > +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, >
With the above :
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
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