linux-toradex.git/drivers/cpufreq/cpufreq-nforce2.c, branch v5.8-rc2

cpufreq: Avoid creating excessively large stack frames

2020-01-27T09:33:33+00:00

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

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166

2019-05-30T18:26:39+00:00

Based on 1 normalized pattern(s):

  licensed under the terms of the gnu gpl license version 2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 62 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Kate Stewart 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.929121379@linutronix.de
Signed-off-by: Greg Kroah-Hartman

cpufreq: nforce2: Remove meaningless return

2018-12-11T11:11:46+00:00

Delete a line of meaningless return and some useless blank lines. In a function
whose return type is void, returning on the last line is not required.

Signed-off-by: Yangtao Li 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Add CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING cpufreq driver flag

2017-07-25T22:15:46+00:00

The policy->transition_latency field is used for multiple purposes
today and its not straight forward at all. This is how it is used:

A. Set the correct transition_latency value.

B. Set it to CPUFREQ_ETERNAL because:
   1. We don't want automatic dynamic switching (with
      ondemand/conservative) to happen at all.
   2. We don't know the transition latency.

This patch handles the B.1. case in a more readable way. A new flag for
the cpufreq drivers is added to disallow use of cpufreq governors which
have dynamic_switching flag set.

All the current cpufreq drivers which are setting transition_latency
unconditionally to CPUFREQ_ETERNAL are updated to use it. They don't
need to set transition_latency anymore.

There shouldn't be any functional change after this patch.

Signed-off-by: Viresh Kumar 
Reviewed-by: Dominik Brodowski 
Signed-off-by: Rafael J. Wysocki

cpufreq: Use consistent prefixing via pr_fmt

2016-04-08T23:35:18+00:00

Use the more common kernel style adding a define for pr_fmt.

Miscellanea:

o Remove now unused PFX defines

Signed-off-by: Joe Perches 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Convert printk(KERN_ to pr_

2016-04-08T23:35:18+00:00

Use the more common logging style.

Miscellanea:

o Coalesce formats
o Realign arguments
o Add a missing space between a coalesced format

Signed-off-by: Joe Perches 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: nforce2: Fix typo in comment to function nforce2_init()

2015-06-15T13:45:24+00:00

Signed-off-by: Shailendra Verma 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: nforce2: remove DEFINE_PCI_DEVICE_TABLE macro

2014-05-16T23:16:15+00:00

Don't use DEFINE_PCI_DEVICE_TABLE macro, because this macro
is deprecated.

Signed-off-by: Jingoo Han 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end}

2014-03-26T15:41:41+00:00

CPUFreq core has new infrastructure that would guarantee serialized calls to
target() or target_index() callbacks. These are called
cpufreq_freq_transition_begin() and cpufreq_freq_transition_end().

This patch converts existing drivers to use these new set of routines.

Reviewed-by: Srivatsa S. Bhat 
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: nforce2: don't initialize part of policy set by core

2013-10-15T22:50:29+00:00

Many common initializations of struct policy are moved to core now and hence
this driver doesn't need to do it. This patch removes such code.

Most recent of those changes is to call ->get() in the core after calling
->init().

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki