interconnect: constify of_phandle_args in xlate

The xlate callbacks are supposed to translate of_phandle_args to proper
provider without modifying the of_phandle_args. Make the argument
pointer to const for code safety and readability.

Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Thierry Reding <treding@nvidia.com> # Tegra
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Alim Akhtar <alim.akhtar@samsung.com> # Samsung
Link: https://lore.kernel.org/r/20240220072213.35779-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

interconnect: qcom: Annotate struct icc_onecell_data with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct icc_onecell_data.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Georgi Djakov <djakov@kernel.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230817204215.never.916-kees@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

interconnect: drop unused icc_link_destroy() interface

Now that the link array is deallocated when destroying nodes and the
explicit link removal has been dropped from the exynos driver there are
no further users of and no need for the icc_link_destroy() interface.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230306075651.2449-24-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

interconnect: drop racy registration API

Now that all interconnect drivers have been converted to the new
provider registration API, the old racy interface can be removed.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230306075651.2449-22-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

interconnect: fix provider registration API

The current interconnect provider interface is inherently racy as
providers are expected to be added before being fully initialised.

Specifically, nodes are currently not added and the provider data is not
initialised until after registering the provider which can cause racing
DT lookups to fail.

Add a new provider API which will be used to fix up the interconnect
drivers.

The old API is reimplemented using the new interface and will be removed
once all drivers have been fixed.

Fixes: 11f1ceca7031 ("interconnect: Add generic on-chip interconnect API")
Fixes: 87e3031b6fbd ("interconnect: Allow endpoints translation via DT")
Cc: stable@vger.kernel.org # 5.1
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # i.MX8MP MSC SM2-MB-EP1 Board
Link: https://lore.kernel.org/r/20230306075651.2449-4-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

interconnect: Make icc_provider_del() return void

All users ignore the return value of icc_provider_del(). Consequently
make it not return an error code.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220718121409.171773-8-u.kleine-koenig@pengutronix.de
Signed-off-by: Georgi Djakov <djakov@kernel.org>

interconnect: Add sync state support

The bootloaders often do some initial configuration of the interconnects
in the system and we want to keep this configuration until all consumers
have probed and expressed their bandwidth needs. This is because we don't
want to change the configuration by starting to disable unused paths until
every user had a chance to request the amount of bandwidth it needs.

To accomplish this we will implement an interconnect specific sync_state
callback which will synchronize (aggregate and set) the current bandwidth
settings when all consumers have been probed.

Link: https://lore.kernel.org/r/20200825170152.6434-3-georgi.djakov@linaro.org
Reviewed-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

interconnect: Add get_bw() callback

The interconnect controller hardware may support querying the current
bandwidth settings, so add a callback for providers to implement this
functionality if supported.

Link: https://lore.kernel.org/r/20200825170152.6434-2-georgi.djakov@linaro.org
Reviewed-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

interconnect: Introduce xlate_extended() callback

Currently there is the xlate() callback, which is used by providers for
mapping the nodes from phandle arguments. That's fine for simple mappings,
but the phandle arguments could contain an additional data, such as tag
information. Let's create another callback xlate_extended() for the cases
where providers want also populate the path tag data.

Tested-by: Sibi Sankar <sibis@codeaurora.org>
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20200903133134.17201-2-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

interconnect: Mark all dummy functions as static inline

There are a few dummy stub functions that are not marked as static inline
yet. Currently this header file is not included in any other file outside
of drivers/interconnect/, but that might not be the case in the future.
If this file gets included and the framework is disabled, we will be see
warnings. Let's fix this in advance.

Link: https://lore.kernel.org/r/20200228145945.13579-1-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

interconnect: Allow inter-provider pairs to be configured

This patch adds support for a new boolean 'inter_set' field in struct
icc_provider. Setting it to 'true' enables calling '->set' for
inter-provider node pairs. All existing users of the interconnect
framework allocate this structure with kzalloc, and are therefore
unaffected by this change.

This makes it easier for hierarchies like exynos-bus, where every bus
is probed separately and registers a separate interconnect provider, to
model constraints between buses.

Signed-off-by: Artur Świgoń <a.swigon@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200521122841.8867-4-s.nawrocki@samsung.com
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

interconnect: Export of_icc_get_from_provider()

This patch makes the above function public (for use in exynos-bus devfreq
driver).

Signed-off-by: Artur Świgoń <a.swigon@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Link: https://lore.kernel.org/r/20200521122841.8867-2-s.nawrocki@samsung.com
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

interconnect: Add a common standard aggregate function

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>

interconnect: Add a common helper for removing all nodes

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>

interconnect: Add pre_aggregate() callback

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>

interconnect: Add support for path tags

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>

interconnect: Allow endpoints translation via DT

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>

interconnect: Add generic on-chip interconnect API

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>