Message ID | 1610511498-4058-9-git-send-email-anshuman.khandual@arm.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | arm64: coresight: Enable ETE and TRBE | expand |
On 1/13/21 4:18 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> > --- > drivers/hwtracing/coresight/coresight-core.c | 14 ++++++++++++++ > include/linux/coresight.h | 12 ++++++++++++ > 2 files changed, 26 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c > index 0062c89..b300606 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; > @@ -998,6 +1006,12 @@ coresight_find_default_sink(struct coresight_device *csdev) > { > int depth = 0; > > + if (coresight_is_percpu_source(csdev)) { On a system without per_cpu sink, this would reset the default sink for the source device every single time and fallback to searching every single time. So I think it would be better if did check if the def_sink was not set. We could fold this into the case below may be. i.e, 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); } Otherwise looks good to me. Suzuki
On 1/13/21 3:13 PM, Suzuki K Poulose wrote: > On 1/13/21 4:18 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> >> --- >> drivers/hwtracing/coresight/coresight-core.c | 14 ++++++++++++++ >> include/linux/coresight.h | 12 ++++++++++++ >> 2 files changed, 26 insertions(+) >> >> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c >> index 0062c89..b300606 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; >> @@ -998,6 +1006,12 @@ coresight_find_default_sink(struct coresight_device *csdev) >> { >> int depth = 0; >> + if (coresight_is_percpu_source(csdev)) { > > On a system without per_cpu sink, this would reset the default sink for the source device > every single time and fallback to searching every single time. Right. > So I think it would be better if did check if the def_sink was not set. > We could fold this into the case below may be. i.e, > > > 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); > } > > Otherwise looks good to me. struct coresight_device * 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) { 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; } Would this be better instead ? coresight_find_sink() is invoked both when the source is not percpu (traditional coresight sources) and also as a fallback in case a percpu sink is not found for the percpu source device.
On 1/15/21 2:36 AM, Anshuman Khandual wrote: > > > On 1/13/21 3:13 PM, Suzuki K Poulose wrote: >> On 1/13/21 4:18 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> >>> --- >>> drivers/hwtracing/coresight/coresight-core.c | 14 ++++++++++++++ >>> include/linux/coresight.h | 12 ++++++++++++ >>> 2 files changed, 26 insertions(+) >>> >>> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c >>> index 0062c89..b300606 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; >>> @@ -998,6 +1006,12 @@ coresight_find_default_sink(struct coresight_device *csdev) >>> { >>> int depth = 0; >>> + if (coresight_is_percpu_source(csdev)) { >> >> On a system without per_cpu sink, this would reset the default sink for the source device >> every single time and fallback to searching every single time. > > Right. > >> So I think it would be better if did check if the def_sink was not set. >> We could fold this into the case below may be. i.e, >> >> >> 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); >> } >> >> Otherwise looks good to me. > > struct coresight_device * > 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) { > 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; > } > > Would this be better instead ? coresight_find_sink() is invoked both when the > source is not percpu (traditional coresight sources) and also as a fallback in > case a percpu sink is not found for the percpu source device. Yes, this is exactly what I proposed above. Cheers Suzuki
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 0062c89..b300606 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; @@ -998,6 +1006,12 @@ coresight_find_default_sink(struct coresight_device *csdev) { int depth = 0; + if (coresight_is_percpu_source(csdev)) { + csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev)); + if (csdev->def_sink) + return csdev->def_sink; + } + /* 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); diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 267c3ac..e019182 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,
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> --- drivers/hwtracing/coresight/coresight-core.c | 14 ++++++++++++++ include/linux/coresight.h | 12 ++++++++++++ 2 files changed, 26 insertions(+)