The 'icc_bw_lock' mutex is introduced in commit af42269c35
("interconnect: Fix locking for runpm vs reclaim") in order to decouple
serialization of bw aggregation from codepaths that require memory
allocation.
However commit d30f83d278 ("interconnect: core: Add dynamic id
allocation support") added a devm_kasprintf() call into a path protected
by the 'icc_bw_lock' which causes the following lockdep warning on
machines like the Lenovo ThinkPad X13s:
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc3 #15 Not tainted
------------------------------------------------------
(udev-worker)/342 is trying to acquire lock:
ffffb973f7ec4638 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_node_track_caller_noprof+0xa0/0x3e0
but task is already holding lock:
ffffb973f7f7f0e8 (icc_bw_lock){+.+.}-{4:4}, at: icc_node_add+0x44/0x154
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (icc_bw_lock){+.+.}-{4:4}:
icc_init+0x48/0x108
do_one_initcall+0x64/0x30c
kernel_init_freeable+0x27c/0x500
kernel_init+0x20/0x1d8
ret_from_fork+0x10/0x20
-> #0 (fs_reclaim){+.+.}-{0:0}:
__lock_acquire+0x136c/0x2114
lock_acquire+0x1c8/0x354
fs_reclaim_acquire+0x74/0xa8
__kmalloc_node_track_caller_noprof+0xa0/0x3e0
devm_kmalloc+0x54/0x124
devm_kvasprintf+0x74/0xd4
devm_kasprintf+0x58/0x80
icc_node_add+0xb4/0x154
qcom_osm_l3_probe+0x20c/0x314 [icc_osm_l3]
platform_probe+0x68/0xd8
really_probe+0xc0/0x38c
__driver_probe_device+0x7c/0x160
driver_probe_device+0x40/0x110
__driver_attach+0xfc/0x208
bus_for_each_dev+0x74/0xd0
driver_attach+0x24/0x30
bus_add_driver+0x110/0x234
driver_register+0x60/0x128
__platform_driver_register+0x24/0x30
osm_l3_driver_init+0x20/0x1000 [icc_osm_l3]
do_one_initcall+0x64/0x30c
do_init_module+0x58/0x23c
load_module+0x1df8/0x1f70
init_module_from_file+0x88/0xc4
idempotent_init_module+0x188/0x280
__arm64_sys_finit_module+0x6c/0xd8
invoke_syscall+0x48/0x110
el0_svc_common.constprop.0+0xc0/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x4c/0x158
el0t_64_sync_handler+0xc8/0xcc
el0t_64_sync+0x198/0x19c
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(icc_bw_lock);
lock(fs_reclaim);
lock(icc_bw_lock);
lock(fs_reclaim);
*** DEADLOCK ***
The icc_node_add() functions is not designed to fail, and as such it
should not do any memory allocation. In order to avoid this, add a new
helper function for the name generation to be called by drivers which
are using the new dynamic id feature.
Fixes: d30f83d278 ("interconnect: core: Add dynamic id allocation support")
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://lore.kernel.org/r/20250625-icc-bw-lockdep-v3-1-2b8f8b8987c4@gmail.com
Co-developed-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20250627075854.26943-1-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>
The current interconnect framework relies on static IDs for node
creation and registration, which limits topologies with multiple
instances of the same interconnect provider. To address this,
introduce icc_node_create_dyn() and icc_link_nodes() APIs to
dynamically allocate IDs for interconnect nodes during creation
and link. This change removes the dependency on static IDs,
allowing multiple instances of the same hardware, such as EPSS L3.
Signed-off-by: Raviteja Laggyshetty <quic_rlaggysh@quicinc.com>
Link: https://lore.kernel.org/r/20250415095343.32125-3-quic_rlaggysh@quicinc.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
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>
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>
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>
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>
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: 11f1ceca70 ("interconnect: Add generic on-chip interconnect API")
Fixes: 87e3031b6f ("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>
* icc-syncstate:
interconnect: Add get_bw() callback
interconnect: Add sync state support
interconnect: qcom: Use icc_sync_state
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
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>
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>
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>
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>
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>
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>
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 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>
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>
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>
