| Message ID | 1611737738-1493-9-git-send-email-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: coresight: Enable ETE and TRBE | expand |
On 1/27/21 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>
On Thu, Jan 28, 2021 at 09:16:34AM +0000, Suzuki K Poulose wrote: > 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); The return value for _coresight_build_path() needs to be checked. Otherwise a failure to allocate a node for the sink will go unoticed and make for a very hard problem to debug. > > + 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, Do we absolutely need to add a new sink type? It is only used in _coresight_build_path() and that code could be: if (coresight_is_percpu_source(csdev)) { sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev)); if (sink && sink == csdev) { _coresight_build_path(sink, sink, path); > > }; > > 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>
HI Anshuman On Wed, 27 Jan 2021 at 08:55, Anshuman Khandual <anshuman.khandual@arm.com> 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. > Really need to tighten up the terminology here - I think what you mean is a PE architecturally defined sink - i.e. one that can be determined by reading the feature registers on the PE, rather than an ETR which cannot. However, the Coresight Base System Architecture specification does recommend a per cpu design using an ETR per CPU - now I assume that this case is not catered for in this patch? > 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. > CORESIGHT_DEV_SUBTYPE_SOURCE_PERCPU_PROC - this does not exist. > > 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); > If you do indeed mean the architecturally defined sinks then this could be 'csdev_pe_arch_sink' - or something similar to indicate the reliance on the PE architecture, unless per-cpu ETR topologies are also handled here. > /** > * 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, If this is needed then could it not be ..._SINK_SYSMEM_PROC - to be consistent with ..._SOURCE_PROC? > }; > > 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) All cpu sources are per cpu - that is ETMv3, ETMv4, PTM, ETE - this might be better as simply coresight_is_cpu_source() as all the aforementioned types will return true. > +{ > + 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, > -- > 2.7.4 > Regards Mike
On Mon, Feb 15, 2021 at 04:27:26PM +0000, Mike Leach wrote: > HI Anshuman > > On Wed, 27 Jan 2021 at 08:55, Anshuman Khandual > <anshuman.khandual@arm.com> 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. > > > > Really need to tighten up the terminology here - I think what you mean > is a PE architecturally defined sink - i.e. one that can be determined > by reading the feature registers on the PE, rather than an ETR which > cannot. > However, the Coresight Base System Architecture specification does > recommend a per cpu design using an ETR per CPU - now I assume that > this case is not catered for in this patch? > > > 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. > > > > CORESIGHT_DEV_SUBTYPE_SOURCE_PERCPU_PROC - this does not exist. > > > > > 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); > > > > If you do indeed mean the architecturally defined sinks then this > could be 'csdev_pe_arch_sink' - or something similar to indicate the > reliance on the PE architecture, unless per-cpu ETR topologies are > also handled here. I would like to treat systems with one ETR per CPU the same way we do for TRBEs. That way we have two distinct way of working, i.e topologies where the sink is shared and 1:1 topologies. As such moving forward with "csdev_pe_arch_sink" could become misleading when 1:1 ETR topologies are supported. Mathieu > > > /** > > * 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, > > If this is needed then could it not be ..._SINK_SYSMEM_PROC - to be > consistent with ..._SOURCE_PROC? > > > }; > > > > 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) > > All cpu sources are per cpu - that is ETMv3, ETMv4, PTM, ETE - this > might be better as simply coresight_is_cpu_source() as all the > aforementioned types will return true. > > > +{ > > + 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, > > -- > > 2.7.4 > > > > Regards > > Mike > -- > Mike Leach > Principal Engineer, ARM Ltd. > Manchester Design Centre. UK
Hi Mathieu, On Mon, 15 Feb 2021 at 16:56, Mathieu Poirier <mathieu.poirier@linaro.org> wrote: > > On Mon, Feb 15, 2021 at 04:27:26PM +0000, Mike Leach wrote: > > HI Anshuman > > > > On Wed, 27 Jan 2021 at 08:55, Anshuman Khandual > > <anshuman.khandual@arm.com> 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. > > > > > > > Really need to tighten up the terminology here - I think what you mean > > is a PE architecturally defined sink - i.e. one that can be determined > > by reading the feature registers on the PE, rather than an ETR which > > cannot. > > However, the Coresight Base System Architecture specification does > > recommend a per cpu design using an ETR per CPU - now I assume that > > this case is not catered for in this patch? > > > > > 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. > > > > > > > CORESIGHT_DEV_SUBTYPE_SOURCE_PERCPU_PROC - this does not exist. > > > > > > > > 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); > > > > > > > If you do indeed mean the architecturally defined sinks then this > > could be 'csdev_pe_arch_sink' - or something similar to indicate the > > reliance on the PE architecture, unless per-cpu ETR topologies are > > also handled here. > > I would like to treat systems with one ETR per CPU the same way we do for TRBEs. > That way we have two distinct way of working, i.e topologies where the sink is > shared and 1:1 topologies. As such moving forward with "csdev_pe_arch_sink" > could become misleading when 1:1 ETR topologies are supported. > > Mathieu > I believe that In terms of connecting source -> sink for 1:1 ETM:ETR, then the existing code will already work via the normal build path and ports declarations. Suzukis changes in coresight-etm-perf to allow multiple sinks of the same type to be active for ETE:TRBE will also work for ETx:ETR. (at least in terms of path building - there may still be other issues that come into play about buffers etc). The TRBE .dts doesn''t have any ports and is as such outside this framework. This patch appears to be making it detectable when connecting source -> sink where we have ETE:TRBE on a given CPU - as in the subsequent patches, the TRBE driver registers in the per cpu sink array. So these changes are not really related to 1:1 specifically, but the detectability of PE architected sinks. There is a need for the per cpu array for TRBE as there is no other way of finding them - but not for ETR - which should work just fine without changes I think. Regards Mike > > > > > /** > > > * 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, > > > > If this is needed then could it not be ..._SINK_SYSMEM_PROC - to be > > consistent with ..._SOURCE_PROC? > > > > > }; > > > > > > 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) > > > > All cpu sources are per cpu - that is ETMv3, ETMv4, PTM, ETE - this > > might be better as simply coresight_is_cpu_source() as all the > > aforementioned types will return true. > > > > > +{ > > > + 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, > > > -- > > > 2.7.4 > > > > > > > Regards > > > > Mike > > -- > > Mike Leach > > Principal Engineer, ARM Ltd. > > Manchester Design Centre. UK -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
On 1/28/21 2:46 PM, Suzuki K Poulose wrote: > 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. Okay, will do. > >> +} >> + >> +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; Okay, will add here as well. >> +} >> #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>
On 2/5/21 12:04 AM, Mathieu Poirier wrote: > On Thu, Jan 28, 2021 at 09:16:34AM +0000, Suzuki K Poulose wrote: >> 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); > > The return value for _coresight_build_path() needs to be checked. Otherwise a > failure to allocate a node for the sink will go unoticed and make for a very > hard problem to debug. How about this instead ? diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 4795e28..e93e669 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -787,9 +787,10 @@ static int _coresight_build_path(struct coresight_device *csdev, 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; + if (_coresight_build_path(sink, sink, path) == 0) { + found = true; + goto out; + } } /* Not a sink - recursively explore each port found on this element */ > >>> + 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, > > Do we absolutely need to add a new sink type? It is only used in > _coresight_build_path() and that code could be: > > if (coresight_is_percpu_source(csdev)) { > sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev)); Do you mean if (sink == per_cpu(...)) above ? > if (sink && sink == csdev) { How could the sink fetched from the source csdev be the same ? I would still suggest keeping CORESIGHT_DEV_SUBTYPE_SINK_PERCPU_SYSMEM for logical separation between source and sink, which also improves clarity and readability.
On Mon, Feb 15, 2021 at 05:58:37PM +0000, Mike Leach wrote: > Hi Mathieu, > > On Mon, 15 Feb 2021 at 16:56, Mathieu Poirier > <mathieu.poirier@linaro.org> wrote: > > > > On Mon, Feb 15, 2021 at 04:27:26PM +0000, Mike Leach wrote: > > > HI Anshuman > > > > > > On Wed, 27 Jan 2021 at 08:55, Anshuman Khandual > > > <anshuman.khandual@arm.com> 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. > > > > > > > > > > Really need to tighten up the terminology here - I think what you mean > > > is a PE architecturally defined sink - i.e. one that can be determined > > > by reading the feature registers on the PE, rather than an ETR which > > > cannot. > > > However, the Coresight Base System Architecture specification does > > > recommend a per cpu design using an ETR per CPU - now I assume that > > > this case is not catered for in this patch? > > > > > > > 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. > > > > > > > > > > CORESIGHT_DEV_SUBTYPE_SOURCE_PERCPU_PROC - this does not exist. > > > > > > > > > > > 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); > > > > > > > > > > If you do indeed mean the architecturally defined sinks then this > > > could be 'csdev_pe_arch_sink' - or something similar to indicate the > > > reliance on the PE architecture, unless per-cpu ETR topologies are > > > also handled here. > > > > I would like to treat systems with one ETR per CPU the same way we do for TRBEs. > > That way we have two distinct way of working, i.e topologies where the sink is > > shared and 1:1 topologies. As such moving forward with "csdev_pe_arch_sink" > > could become misleading when 1:1 ETR topologies are supported. > > > > Mathieu > > > > I believe that In terms of connecting source -> sink for 1:1 ETM:ETR, > then the existing code will already work via the normal build path and > ports declarations. Suzukis changes in coresight-etm-perf to allow > multiple sinks of the same type to be active for ETE:TRBE will also > work for ETx:ETR. (at least in terms of path building - there may > still be other issues that come into play about buffers etc). > > The TRBE .dts doesn''t have any ports and is as such outside this > framework. This patch appears to be making it detectable when > connecting source -> sink where we have ETE:TRBE on a given CPU - as > in the subsequent patches, the TRBE driver registers in the per cpu > sink array. > > So these changes are not really related to 1:1 specifically, but the > detectability of PE architected sinks. There is a need for the per cpu > array for TRBE as there is no other way of finding them - but not for > ETR - which should work just fine without changes I think. I thought about this further after reading the above... ETRs have ports, they are present in the DTS and are already supported. There is no point in trying to handle them the same way TRBEs are handled in this set. We can look at the (potential) advantage of doing so at a later time if the need arises but not in this set. Thanks, Mathieu > > Regards > > Mike > > > > > > > > > /** > > > > * 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, > > > > > > If this is needed then could it not be ..._SINK_SYSMEM_PROC - to be > > > consistent with ..._SOURCE_PROC? > > > > > > > }; > > > > > > > > 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) > > > > > > All cpu sources are per cpu - that is ETMv3, ETMv4, PTM, ETE - this > > > might be better as simply coresight_is_cpu_source() as all the > > > aforementioned types will return true. > > > > > > > +{ > > > > + 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, > > > > -- > > > > 2.7.4 > > > > > > > > > > Regards > > > > > > Mike > > > -- > > > Mike Leach > > > Principal Engineer, ARM Ltd. > > > Manchester Design Centre. UK > > > > -- > Mike Leach > Principal Engineer, ARM Ltd. > Manchester Design Centre. UK
On Tue, Feb 16, 2021 at 04:10:18PM +0530, Anshuman Khandual wrote: > > > On 2/5/21 12:04 AM, Mathieu Poirier wrote: > > On Thu, Jan 28, 2021 at 09:16:34AM +0000, Suzuki K Poulose wrote: > >> 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); > > > > The return value for _coresight_build_path() needs to be checked. Otherwise a > > failure to allocate a node for the sink will go unoticed and make for a very > > hard problem to debug. > > How about this instead ? > > diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c > index 4795e28..e93e669 100644 > --- a/drivers/hwtracing/coresight/coresight-core.c > +++ b/drivers/hwtracing/coresight/coresight-core.c > @@ -787,9 +787,10 @@ static int _coresight_build_path(struct coresight_device *csdev, > > 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; > + if (_coresight_build_path(sink, sink, path) == 0) { > + found = true; > + goto out; > + } I am missing the context now but it is a step in the right direction. I will re-assess on your next revision. > } > > /* Not a sink - recursively explore each port found on this element */ > > > > >>> + 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, > > > > Do we absolutely need to add a new sink type? It is only used in > > _coresight_build_path() and that code could be: > > > > if (coresight_is_percpu_source(csdev)) { > > sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev)); > > Do you mean if (sink == per_cpu(...)) above ? > > > if (sink && sink == csdev) { > > How could the sink fetched from the source csdev be the same ? The above should have been: if (coresight_is_percpu_source(csdev)) { per_cpu_sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev)); if (per_cpu_sink && per_cpu_sink == sink) { Apologies for the confusion. Mathieu > > I would still suggest keeping CORESIGHT_DEV_SUBTYPE_SINK_PERCPU_SYSMEM for > logical separation between source and sink, which also improves clarity > and readability.
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; +} + +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> --- 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(-)