The interconnect graphs can be difficult to understand and the current
"interconnect_summary" file doesn't even display links in any way.
Add a new "interconnect_graph" file to debugfs in the graphviz "dot"
format which describes interconnect providers, nodes and links.
The file is human-readable and can be visualized by piping through
graphviz. Example:
ssh $TARGET cat /sys/kernel/debug/interconnect/interconnect_graph \
| dot -Tsvg > interconnect_graph.svg
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Currently there is one very standard aggregation method that is used by
several drivers. Let's add this as a common function, so that drivers
could just point to it, instead of copy/pasting code.
Suggested-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
The tracepoints can help with understanding the system behavior of a
given interconnect path when the consumer drivers change their bandwidth
demands. This might be interesting when we want to monitor the requested
interconnect bandwidth for each client driver. The paths may share the
same nodes and this will help to understand "who and when is requesting
what". All this is useful for subsystem drivers developers and may also
provide hints when optimizing the power and performance profile of the
system.
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
When debugging interconnect things, it turned out that saving the path
name and including it in the traces is quite useful, especially for
devices with multiple paths.
For the path name we use the one specified in DT, or if we use platform
data, the name is based on the source and destination node names.
Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Move the interconnect framework internal structs into a separate file,
so that it can be included and used by ftrace code. This will allow us
to expose some more useful information in the traces.
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
The removal of all nodes from a provider seem to be a common functionality
for all existing users and it would make sense to factor out this into a
a common helper function.
Suggested-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
We must ensure that the tag is not changed while we aggregate the
requests. Currently the icc_set_tag() is not using any locks and this
may cause the values to be aggregated incorrectly. Fix this by acquiring
the icc_lock while we set the tag.
Link: https://lore.kernel.org/lkml/20191018141750.17032-1-georgi.djakov@linaro.org/
Fixes: 127ab2cc5f ("interconnect: Add support for path tags")
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Introduce an optional callback in interconnect provider drivers. It can be
used for implementing actions, that need to be executed before the actual
aggregation of the bandwidth requests has started.
The benefit of this for now is that it will significantly simplify the code
in provider drivers.
Suggested-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Consumers may have use cases with different bandwidth requirements based
on the system or driver state. The consumer driver can append a specific
tag to the path and pass this information to the interconnect platform
driver to do the aggregation based on this state.
Introduce icc_set_tag() function that will allow the consumers to append
an optional tag to each path. The aggregation of these tagged paths is
platform specific.
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
When consumers report their bandwidth needs with icc_set_bw(), it's
possible that the requested amount of bandwidth is not available or just
the new configuration fails to apply on some path. In this case revert to
the previous configuration and propagate the error back to the consumers
to let them know that bandwidth is not available, hardware is busy or
whatever error is returned by the interconnect platform driver.
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a functionality to provide information about the current constraints
per each node and provider.
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently we support only platform data for specifying the interconnect
endpoints. As now the endpoints are hard-coded into the consumer driver
this may lead to complications when a single driver is used by multiple
SoCs, which may have different interconnect topology.
To avoid cluttering the consumer drivers, introduce a translation function
to help us get the board specific interconnect data from device-tree.
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch introduces a new API to get requirements and configure the
interconnect buses across the entire chipset to fit with the current
demand.
The API is using a consumer/provider-based model, where the providers are
the interconnect buses and the consumers could be various drivers.
The consumers request interconnect resources (path) between endpoints and
set the desired constraints on this data flow path. The providers receive
requests from consumers and aggregate these requests for all master-slave
pairs on that path. Then the providers configure each node along the path
to support a bandwidth that satisfies all bandwidth requests that cross
through that node. The topology could be complicated and multi-tiered and
is SoC specific.
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
