Later commits would change the way policies are managed today. Policies
wouldn't be freed on cpu hotplug (currently they aren't freed only for
suspend), and while the CPU is offline, the sysfs cpufreq files would
still be present.
User may accidentally try to update the sysfs files in following
directory: '/sys/devices/system/cpu/cpuX/cpufreq/'. And that would
result in undefined behavior as policy wouldn't be active then.
Apart from updating the store() routine, we also update __cpufreq_get()
which can call cpufreq_out_of_sync(). The later routine tries to update
policy->cur and starts notifying kernel about it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
During initialization and exit it is possible that the target pstate
might not actually be set. Furthermore, the result can be that the
driver and the processor are out of synch and, under some conditions,
the driver might never send the processor the proper target pstate.
This patch adds a bypass or do_checks flag to the call to
intel_pstate_set_pstate. If bypass, then specifically bypass clamp
checks and the do not send if it is the same as last time check. If
do_checks, then, and as before, do the current policy clamp checks,
and do not do actual send if the new target is the same as the old.
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Reported-by: Marien Zwart <marien.zwart@gmail.com>
Reported-by: Alex Lochmann <alexander.lochmann@tu-dortmund.de>
Reported-by: Piotr Ko?aczkowski <pkolaczk@gmail.com>
Reported-by: Clemens Eisserer <linuxhippy@gmail.com>
Tested-by: Marien Zwart <marien.zwart@gmail.com>
Tested-by: Doug Smythies <dsmythies@telus.net>
[ rjw: Dropped pointless symbol definitions, rebased ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit ce717613f3 (intel_pstate: Turn per cpu printk into pr_debug)
turned per cpu printk into pr_debug. However, only half of the change
was done, introducing an inconsistency between entry and exit from
driver pstate control. This patch changes the exit message to pr_debug
also.
The various messages are inconsistent with respect to any identifier
text that can be used to help isolate the desired information from a
huge log. This patch makes a consistent identifier portion of the
string.
Amends: ce717613f3 (intel_pstate: Turn per cpu printk into pr_debug)
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In order to prepare for the next few commits, that will stop migrating
sysfs files on cpu hotplug, this patch starts managing sysfs-cpu
separately.
The behavior is still the same as we are still migrating sysfs files on
hotplug, later commits would change that.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Later commits would change the way policies are managed today. Policies
wouldn't be freed on cpu hotplug (currently they aren't freed on
suspend), and while the CPU is offline, the sysfs cpufreq files would
still be present.
Because we don't mark policy->governor as NULL, it still contains
pointer of the last used governor. And if the governor is removed, while
all the CPUs of a policy are hotplugged out, this pointer wouldn't be
valid anymore. And if we try to read the 'scaling_governor', etc. from
sysfs, it will result in kernel OOPs.
To prevent this, mark policy->governor as NULL for all inactive policies
while the governor is removed from kernel.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
History of which governor was used last is common to all CPUs within a
policy and maintaining it per-cpu isn't the best approach for sure.
Apart from wasting memory, this also increases the complexity of
managing this data structure as it has to be updated for all CPUs.
To make that somewhat simpler, lets store this information in a new
field 'last_governor' in struct cpufreq_policy and update it on removal
of last cpu of a policy.
As a side-effect it also solves an old problem, consider a system with
two clusters 0 & 1. And there is one policy per cluster.
Cluster 0: CPU0 and 1.
Cluster 1: CPU2 and 3.
- CPU2 is first brought online, and governor is set to performance
(default as cpufreq_cpu_governor wasn't set).
- Governor is changed to ondemand.
- CPU2 is taken offline and cpufreq_cpu_governor is updated for CPU2.
- CPU3 is brought online.
- Because cpufreq_cpu_governor wasn't set for CPU3, the default governor
performance is picked for CPU3.
This patch fixes the bug as we now have a single variable to update for
policy.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We reach here while adding policy for a CPU and enter into the 'if'
block only if a policy already exists for the CPU.
As cpufreq_cpu_data is set for all policy->related_cpus now, when the
policy is first added, we can use that to find the CPU's policy instead
of traversing the list of all active policies.
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We can extract the same information from cpufreq_cpu_data as it is also
available for inactive policies now. And so don't need
cpufreq_cpu_data_fallback anymore.
Also add a WARN_ON() for the case where we try to restore from an active
policy.
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Now that we can check policy->cpus to find if policy is active or not,
we don't need to clean cpufreq_cpu_data and delete policy from the list
on light weight tear down of policies (like in suspend).
To make it consistent and clean, set cpufreq_cpu_data for all related
CPUs when the policy is first created and clean it only while it is
freed.
Also update cpufreq_cpu_get_raw() to check if cpu is part of
policy->cpus mask, so that we don't end up getting policies for offline
CPUs.
In order to make sure that no users of 'policy' are using an inactive
policy, use cpufreq_cpu_get_raw() instead of directly accessing
cpufreq_cpu_data.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
policy->cpus is cleared unconditionally now on hotplug-out of a CPU and
it can be checked to know if a policy is active or not. Create helper
routines to iterate over all active/inactive policies, based on
policy->cpus field.
Replace all instances of for_each_policy() with for_each_active_policy()
to make them iterate only for active policies. (We haven't made changes
yet to keep inactive policies in the same list, but that will be
followed in a later patch).
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
With the addition of switcher code, there's compile-time dependency on
BIG_LITTLE to get arm_big_little driver compiling on ARM64. Since ARM64
will never add support for bL switcher, it's better to remove the
dependency so that the driver can be reused on ARM64 platforms.
This patch adds stubs to remove BIG_LITTLE dependency in the driver.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 007bea098b (intel_pstate: Add setting voltage value for
baytrail P states.) introduced byt_set_pstate() with the assumption that
it would always be run by the CPU whose MSR is to be written by it. It
turns out, however, that is not always the case in practice, so modify
byt_set_pstate() to enforce the MSR write done by it to always happen on
the right CPU.
Fixes: 007bea098b (intel_pstate: Add setting voltage value for baytrail P states.)
Signed-off-by: Joe Konno <joe.konno@intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We clear policy->cpus mask while CPUs are hotplugged out. We do it for all CPUs
except the last CPU of the policy. I don't remember what the rationale behind
that was, but I couldn't think of anything that will break if we remove this
conditional clearing and always clear policy->cpus.
The benefit we get out of it is, we can know if a policy is active or not by
checking if this field is empty or not. That will be used by later commits.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are two cases when we may try to add CPUs we're already handling:
- On boot, the first cpu has marked all policy->cpus managed and so we
will find policy for all other policy->cpus later on.
- When a managed cpu is hotplugged out and later brought back in.
Currently, separate paths and checks take care of the two. While the
first one is detected by testing cpu against 'policy->cpus', the other
one is detected by testing cpu against 'policy->related_cpus'.
We can handle them both via a single path and there is no need to do
special checking for the first one.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
[ rjw: Changelog, comments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Simply returning here with an error is not enough. It shouldn't be allowed at
all to try calling cpufreq_cpu_get() for an invalid CPU.
Add a WARN here to make it clear that it wouldn't be acceptable at all.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The file 'Documentation/cpu-freq/user-guide.txt' has duplicate
description of sysfs interface 'scaling_driver'.
[first]
scaling_driver : this file shows what cpufreq driver is
used to set the frequency on this CPU
[second]
scaling_driver : Hardware driver for cpufreq.
Although this does not affect anything, I think we should only have
one. so delete the second one because the first one is described in
more detail.
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The intel_pstate driver is difficult to debug and investigate without tsc.
Also, it is likely use of tsc, and some version of C0 percentage,
will be re-introdcued in futute.
There have also been occasions where it is desirebale to know, and
confirm, the previous target pstate.
This patch brings back tsc, adds previous target pstate,
and adds both to the trace data collection.
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The "cpu-cluster.<n>" used to get the cluster clock is not used by any
platform. Moreover __of_clk_get_by_name used in clk_get return error if
the "clock-names" in the DT doesn't match this string. When using DT,
it's not compulsory to specify the clock name unless there are multiple
clock input entries in the consumer.
This patch removes the unused clock string from the driver.
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The actual frequency is set through "clk_change_rate" which is void
function. If the underlying hardware fails and returns error, the error
is lost in the clk layer. In order to track such failures, we need to
read back the frequency(just the cached value as clk_recalc called after
clk->ops->set_rate gets the frequency)
This patch adds check to see if the frequency is set correctly or if
they were any hardware failures and sends the appropriate errors to the
cpufreq core.
Reviewed-by: Michael Turquette <mike.turquette@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pxa255_run_freqs and pxa255_turbo_freqs are only read.
This patch updates arrays declaration, find_freq_tables()
and its callsites.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
typedef is not really useful here. Replace it by structure
to improve readability. typedef should only be used in some cases.
(See Documentation/CodingStyle Chapter 5 for details).
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
