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Commit Graph

7 Commits

Author SHA1 Message Date
Georgi Djakov
6ac3f01201 Merge branch 'icc-debugfs' into icc-next
This series introduces interconnect debugfs files that support voting
for any interconnect path the framework supports. It is useful for debug,
test and verification.

* icc-debugfs
  debugfs: Add write support to debugfs_create_str()
  interconnect: Reintroduce icc_get()
  interconnect: Add debugfs test client

Link: https://lore.kernel.org/r/20230807142914.12480-1-quic_mdtipton@quicinc.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-08-22 21:05:09 +03:00
Mike Tipton
770c69f037 interconnect: Add debugfs test client
It's often useful during test, debug, and development to issue path
votes from shell. Add a debugfs client for this purpose.

Example usage:
	cd /sys/kernel/debug/interconnect/test-client/

	# Configure node endpoints for the path from CPU to DDR on
	# qcom/sm8550.
	echo chm_apps > src_node
	echo ebi > dst_node

	# Get path between src_node and dst_node. This is only
	# necessary after updating the node endpoints.
	echo 1 > get

	# Set desired BW to 1GBps avg and 2GBps peak.
	echo 1000000 > avg_bw
	echo 2000000 > peak_bw

	# Vote for avg_bw and peak_bw on the latest path from "get".
	# Voting for multiple paths is possible by repeating this
	# process for different nodes endpoints.
	echo 1 > commit

Allowing userspace to directly enable and set bus rates can be dangerous
So, following in the footsteps of the regmap [0] and clk [1] frameworks,
keep these userspace controls compile-time disabled without Kconfig
options to enable them. Enabling this will require code changes to
define INTERCONNECT_ALLOW_WRITE_DEBUGFS.

[0] commit 09c6ecd394 ("regmap: Add support for writing to regmap registers via debugfs")
[1] commit 37215da555 ("clk: Add support for setting clk_rate via debugfs")

Signed-off-by: Mike Tipton <quic_mdtipton@quicinc.com>
Link: https://lore.kernel.org/r/20230807142914.12480-4-quic_mdtipton@quicinc.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-08-22 21:04:50 +03:00
Mike Tipton
1d13d3b745 interconnect: Reintroduce icc_get()
The original icc_get() that took integer node IDs was removed due to
lack of users. Reintroduce a new version that takes string node names,
which is needed for the debugfs client.

Signed-off-by: Mike Tipton <quic_mdtipton@quicinc.com>
Link: https://lore.kernel.org/r/20230807142914.12480-3-quic_mdtipton@quicinc.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-08-22 21:04:37 +03:00
Kees Cook
6f0c60f146 interconnect: Annotate struct icc_path 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_path.

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

Cc: Georgi Djakov <djakov@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>
Link: https://lore.kernel.org/r/20230817204144.never.605-kees@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-08-22 01:11:22 +03:00
Georgi Djakov
7d374b2090 interconnect: Add helpers for enabling/disabling a path
There is a repeated pattern in multiple drivers where they want to switch
the bandwidth between zero and some other value. This is happening often
in the suspend/resume callbacks. Let's add helper functions to enable and
disable the path, so that callers don't have to take care of remembering
the bandwidth values and handle this in the framework instead.

With this patch the users can call icc_disable() and icc_enable() to lower
their bandwidth request to zero and then restore it back to it's previous
value.

Suggested-by: Evan Green <evgreen@chromium.org>
Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20200507120846.8354-1-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-05-10 18:30:37 +03:00
Georgi Djakov
05309830e1 interconnect: Add a name to struct icc_path
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>
2019-12-16 09:25:23 +02:00
Georgi Djakov
dd018a9cf9 interconnect: Move internal structs into a separate file
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>
2019-12-16 09:25:23 +02:00