kernel/linux.git/drivers/interconnect/core.c, branch v6.13.6

interconnect: Use of_property_present() for non-boolean properties

2024-11-04T23:27:39+00:00

The use of of_property_read_bool() for non-boolean properties is deprecated in favor of of_property_present() when testing for property presence. Signed-off-by: "Rob Herring (Arm)" Link: https://lore.kernel.org/r/20241104190650.275278-1-robh@kernel.org Signed-off-by: Georgi Djakov

interconnect: Remove a useless kfree_const() usage

2024-10-22T08:17:24+00:00

"path->name" is allocated in of_icc_get_by_index() using kasprintf(), so there is no point in using kfree_const() to free it. Switch to the more standard kfree() to free this. Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/06630f9ec3e153d0e7773b8d97a17e7c53e0d606.1727375615.git.christophe.jaillet@wanadoo.fr Signed-off-by: Georgi Djakov

Merge tag 'icc-6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/djakov/icc into char-work-linus

2024-04-11T12:44:49+00:00

Georgi writes: interconnect fixes for v6.9-rc Here are fixes for two reported issues. One of them is a fix for a driver that tries to access a non-existent resource which prints a warning message during boot. The other one is fixing a race condition in the core framework where one struct member has been left unprotected by mutex. - interconnect: qcom: x1e80100: Remove inexistent ACV_PERF BCM - interconnect: Don't access req_list while it's being manipulated Signed-off-by: Georgi Djakov * tag 'icc-6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/djakov/icc: interconnect: Don't access req_list while it's being manipulated interconnect: qcom: x1e80100: Remove inexistent ACV_PERF BCM

interconnect: Don't access req_list while it's being manipulated

2024-03-14T11:51:44+00:00

The icc_lock mutex was split into separate icc_lock and icc_bw_lock mutexes in [1] to avoid lockdep splats. However, this didn't adequately protect access to icc_node::req_list. The icc_set_bw() function will eventually iterate over req_list while only holding icc_bw_lock, but req_list can be modified while only holding icc_lock. This causes races between icc_set_bw(), of_icc_get(), and icc_put(). Example A: CPU0 CPU1 ---- ---- icc_set_bw(path_a) mutex_lock(&icc_bw_lock); icc_put(path_b) mutex_lock(&icc_lock); aggregate_requests() hlist_for_each_entry(r, ... hlist_del(... Example B: CPU0 CPU1 ---- ---- icc_set_bw(path_a) mutex_lock(&icc_bw_lock); path_b = of_icc_get() of_icc_get_by_index() mutex_lock(&icc_lock); path_find() path_init() aggregate_requests() hlist_for_each_entry(r, ... hlist_add_head(... Fix this by ensuring icc_bw_lock is always held before manipulating icc_node::req_list. The additional places icc_bw_lock is held don't perform any memory allocations, so we should still be safe from the original lockdep splats that motivated the separate locks. [1] commit af42269c3523 ("interconnect: Fix locking for runpm vs reclaim") Signed-off-by: Mike Tipton Fixes: af42269c3523 ("interconnect: Fix locking for runpm vs reclaim") Reviewed-by: Rob Clark Link: https://lore.kernel.org/r/20240305225652.22872-1-quic_mdtipton@quicinc.com Signed-off-by: Georgi Djakov

interconnect: constify of_phandle_args in xlate

2024-02-25T22:38:17+00:00

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 Acked-by: Thierry Reding # Tegra Signed-off-by: Krzysztof Kozlowski Acked-by: Alim Akhtar # Samsung Link: https://lore.kernel.org/r/20240220072213.35779-1-krzysztof.kozlowski@linaro.org Signed-off-by: Georgi Djakov

interconnect: Treat xlate() returning NULL node as an error

2023-11-22T12:36:03+00:00

Currently, if provider->xlate() or provider->xlate_extended() "successfully" return a NULL node, then of_icc_get_from_provider() won't consider that an error and will successfully return the NULL node. This bypasses error handling in of_icc_get_by_index() and leads to NULL dereferences in path_find(). This could be avoided by ensuring provider callbacks always return an error for NULL nodes, but it's better to explicitly protect against this in the common framework. Fixes: 87e3031b6fbd ("interconnect: Allow endpoints translation via DT") Signed-off-by: Mike Tipton Link: https://lore.kernel.org/r/20231025145829.11603-1-quic_mdtipton@quicinc.com Signed-off-by: Georgi Djakov

Merge branch 'icc-debugfs' into icc-next

2023-08-22T18:05:09+00:00

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

interconnect: Add debugfs test client

2023-08-22T18:04:50+00:00

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 09c6ecd39410 ("regmap: Add support for writing to regmap registers via debugfs") [1] commit 37215da5553e ("clk: Add support for setting clk_rate via debugfs") Signed-off-by: Mike Tipton Link: https://lore.kernel.org/r/20230807142914.12480-4-quic_mdtipton@quicinc.com Signed-off-by: Georgi Djakov

interconnect: Reintroduce icc_get()

2023-08-22T18:04:37+00:00

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 Link: https://lore.kernel.org/r/20230807142914.12480-3-quic_mdtipton@quicinc.com Signed-off-by: Georgi Djakov

interconnect: Teach lockdep about icc_bw_lock order

2023-08-21T22:25:06+00:00

Teach lockdep that icc_bw_lock is needed in code paths that could deadlock if they trigger reclaim. Signed-off-by: Rob Clark Link: https://lore.kernel.org/r/20230807171148.210181-8-robdclark@gmail.com Signed-off-by: Georgi Djakov