kernel.git/drivers/cpufreq/freq_table.c, branch linux-5.4.y

cpufreq: Avoid creating excessively large stack frames

2020-02-11T12:35:25Z

commit 1e4f63aecb53e48468661e922fc2fa3b83e55722 upstream. In the process of modifying a cpufreq policy, the cpufreq core makes a copy of it including all of the internals which is stored on the CPU stack. Because struct cpufreq_policy is relatively large, this may cause the size of the stack frame to exceed the 2 KB limit and so the GCC complains when -Wframe-larger-than= is used. In fact, it is not necessary to copy the entire policy structure in order to modify it, however. First, because cpufreq_set_policy() obtains the min and max policy limits from frequency QoS now, it is not necessary to pass the limits to it from the callers. The only things that need to be passed to it from there are the new governor pointer or (if there is a built-in governor in the driver) the "policy" value representing the governor choice. They both can be passed as individual arguments, though, so make cpufreq_set_policy() take them this way and rework its callers accordingly. This avoids making copies of cpufreq policies in the callers of cpufreq_set_policy(). Second, cpufreq_set_policy() still needs to pass the new policy data to the ->verify() callback of the cpufreq driver whose task is to sanitize the min and max policy limits. It still does not need to make a full copy of struct cpufreq_policy for this purpose, but it needs to pass a few items from it to the driver in case they are needed (different drivers have different needs in that respect and all of them have to be covered). For this reason, introduce struct cpufreq_policy_data to hold copies of the members of struct cpufreq_policy used by the existing ->verify() driver callbacks and pass a pointer to a temporary structure of that type to ->verify() (instead of passing a pointer to full struct cpufreq_policy to it). While at it, notice that intel_pstate and longrun don't really need to verify the "policy" value in struct cpufreq_policy, so drop those check from them to avoid copying "policy" into struct cpufreq_policy_data (which allows it to be slightly smaller). Also while at it fix up white space in a couple of places and make cpufreq_set_policy() static (as it can be so). Fixes: 3000ce3c52f8 ("cpufreq: Use per-policy frequency QoS") Link: https://lore.kernel.org/linux-pm/CAMuHMdX6-jb1W8uC2_237m8ctCpsnGp=JCxqt8pCWVqNXHmkVg@mail.gmail.com Reported-by: kbuild test robot Reported-by: Geert Uytterhoeven Cc: 5.4+ # 5.4+ Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55Z

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

cpufreq: boost: Remove CONFIG_CPU_FREQ_BOOST_SW Kconfig option

2019-04-10T08:00:50Z

Commit 2fb4719b2560 ("cpufreq / boost: Kconfig: Support for software-managed BOOST") added the CONFIG_CPU_FREQ_BOOST_SW config. However EXYNOS based cpufreq drivers have been removed because of switching to cpufreq-dt driver which will set boost-attr if required. So, let's remove this option and update cpufreq_generic_attr[]. Signed-off-by: Yue Hu Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

cpufreq: Drop cpufreq_table_validate_and_show()

2018-04-10T06:40:45Z

This isn't used anymore. Remove the helper and update documentation accordingly. Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

cpufreq: Validate frequency table in the core

2018-02-27T17:22:12Z

By design, cpufreq drivers are responsible for calling cpufreq_frequency_table_cpuinfo() from their ->init() callbacks to validate the frequency table. However, if a cpufreq driver is buggy and fails to do so properly, it lead to unexpected behavior of the driver or the cpufreq core at a later point in time. It would be better if the core could validate the frequency table during driver initialization. To that end, introduce cpufreq_table_validate_and_sort() and make the cpufreq core call it right after invoking the ->init() callback of the driver and destroy the cpufreq policy if the table is invalid. For the time being the validation of the table happens twice, once from the driver and then from the core. The individual drivers will be updated separately to drop table validation if they don't need it for other reasons. The frequency table is marked "sorted" or "unsorted" by the new helper now instead of in cpufreq_table_validate_and_show(), as it should only be done after validating the table (which the drivers won't do going forward). Signed-off-by: Viresh Kumar [ rjw: Subject/changelog ] Signed-off-by: Rafael J. Wysocki

cpufreq: Add and use cpufreq_for_each_{valid_,}entry_idx()

2018-02-08T09:21:39Z

Pointer subtraction is slow and tedious. Therefore, replace all instances where cpufreq_for_each_{valid_,}entry loops contained such substractions with an iteration macro providing an index to the frequency_table entry. Suggested-by: Al Viro Link: http://lkml.kernel.org/r/20180120020237.GM13338@ZenIV.linux.org.uk Acked-by: Viresh Kumar Signed-off-by: Dominik Brodowski Signed-off-by: Rafael J. Wysocki

cpufreq: Handle sorted frequency tables more efficiently

2016-07-06T22:13:20Z

cpufreq drivers aren't required to provide a sorted frequency table today, and even the ones which provide a sorted table aren't handled efficiently by cpufreq core. This patch adds infrastructure to verify if the freq-table provided by the drivers is sorted or not, and use efficient helpers if they are sorted. Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

cpufreq: Return index from cpufreq_frequency_table_target()

2016-06-08T22:58:06Z

This routine can't fail unless the frequency table is invalid and doesn't contain any valid entries. Make it return the index and WARN() in case it is used for an invalid table. Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

cpufreq: Drop freq-table param to cpufreq_frequency_table_target()

2016-06-08T22:58:06Z

The policy already has this pointer set, use it instead. Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

cpufreq: Remove cpufreq_frequency_get_table()

2016-06-08T22:58:05Z

Most of the callers of cpufreq_frequency_get_table() already have the pointer to a valid 'policy' structure and they don't really need to go through the per-cpu variable first and then a check to validate the frequency, in order to find the freq-table for the policy. Directly use the policy->freq_table field instead for them. Only one user of that API is left after above changes, cpu_cooling.c and it accesses the freq_table in a racy way as the policy can get freed in between. Fix it by using cpufreq_cpu_get() properly. Since there are no more users of cpufreq_frequency_get_table() left, get rid of it. Signed-off-by: Viresh Kumar Acked-by: Javi Merino (cpu_cooling.c) Signed-off-by: Rafael J. Wysocki